Zinc and marble are worked in the neighbourhood.
The principal mining product is mercury, extracted at Idria, while iron and copper ore, zinc and coal are also found.
The joists are covered with a waterproof material such as asphalt, lead, zinc or copper, the three last materials being usually laid upon boarding, which stiffens the structure and forms a good surface to fix the weatherproof covering upon.
Iron, zinc and lead are found in the vicinity, and some coal is mined.
Ore of cobalt is obtained in no other locality in India, and although zinc blende has been found elsewhere it is known to have been extracted only in this province.
In Norwood and Rogers's process a thin coating of tin is applied to the iron before it is dipped in the zinc, by putting the plates between layers of granulated tin in a wooden tank containing a dilute solution of stannous chloride, when tin is deposited on them by galvanic action.
In "cold galvanizing" the zinc is deposited electrolytically from a bath, preferably kept neutral or slightly acid, containing a io% solution of crystallized zinc sulphate, ZnSO 4.7H20.
The output of zinc was 2,168,783 lb (valued at $127,958).
For example, when metallic zinc is dissolved in dilute sulphuric acid with production of zinc sulphate (in solution) and hydrogen gas, a definite quantity of heat is produced for a given amount of zinc dissolved, provided that the excess of energy in the initial system appears entirely as heat.
Thus the heat of formation of anhydrous zinc sulphate, ZnSO 4j which cannot be determined directly, may be arrived at by summation (in Hess's units) as follows: Heats of formation are still determined for the most part in a precisely similar manner.
The Monteponi Company smelts its own zinc, but the lead is almost all smelted at the furnaces of Pertusola near Spezia.
Copper, lead and zinc are produced in small quantities, being found in fissure veins with gold and silver.
There are important zinc works at Auby and St Amand (Nord) and Viviez (Aveyron) and Noyelles-Godault (Pas-de-Calais); there are lead works at the latter place, and others of greater irirportance at Couron (Loire-Infrieure).
Sodium amalgam or zinc and hydrochloric acid reduce it to lactic acid, whilst hydriodic acid gives propionic acid.
GALVANIZED IRON, sheet iron having its surface covered with a thin coating of zinc. In spite of the name, galvanic action has often no part in the production of galvanized iron, which is prepared by dipping the iron, properly cleaned and pickled in acid, in a bath of molten zinc. The hotter the zinc the thinner the coating, but as a high temperature of the bath is attended with certain objections, it is a common practice to use a moderate temperature and clear off the excess of zinc by passing the plates between rollers.
The table below gives the average production of zinc, argentiferous lead, iron-pyrites and other ores during the quinquennial period 1901f 905.
The manufactures comprise sheet-iron, boilers, zinc, brick and tiles, paraffin, petroleum, soap and candles.
zinc with solutions of copper salts), the thermal effect is practically independent of the nature of the acid radical in the salt employed.
The mines near the city are very productive, and thousands of men and beasts are employed in transporting lead, iron, copper, zinc and sulphur to the coast.
Joplin is the trade centre of a rich agricultural and fruit-growing district, but its growth has been chiefly due to its situation in one of the must productive zinc and lead regions in the country, for which it is the commercial centre.
Each cell contains a zinc plate, immersed in a solution of zinc sulphate, and also a porous chamber containing crystals of copper sulphate and a copper plate.
Simultaneously Hermann, a German chemical manufacturer, discovered the new metal in a specimen of zinc oxide which had been thought to contain arsenic, since it gave a yellow precipitate, in acid solution, on the addition of sulphuretted hydrogen.
Zinc ores, in the several varieties of carbonates, silicates, oxide, sulphide and sulphate of zinc, have been found in several of the Australian states, but have attracted little attention except in New South Wales, where special efforts are being made successfully to produce a high-grade zinc concentrate from the sulphide ores.
Several companies are devoting all their energies to zinc extraction, and the output is now equal to about 5% of the world's production.
The most important minerals are lead and zinc, obtained in lodes in the forms of galena and calamine respectively.
The first part will be, as before, zinc to the line; at the next half stroke of the beam M will not pass through, as there is no hole in the paper; but at the third half stroke it passes through and copper is put to the line.
The molybdates may be recognized by the fact that they give a white precipitate on the addition of hydrochloric or nitric acids to their solutions, and that with reducing agents (zinc and sulphuric acid) they give generally a blue coloration which turns to a green and finally to a brown colour.
Vitamins and minerals – zinc and vitamin C were high on the list, and some herbs.
The metal is usually obtained from the flue-dust (produced during the first three or four hours working of a zinc distillation) which is collected in the sheet iron cones or adapters of the zinc retorts.
The bulk of the sulphur mines are in Sicily, while the majority of the lead and zinc mines are in Sardinia; much of the lead smelting is done at Pertusola, near Genoa, the company formed for this purpose having acquired many of the Sardinian mines.
Molybdenum sesquioxide, Mo 2 O 3, a black mass insoluble in acids, is formed by heating the corresponding hydroxide in vacuo, or by digesting the trioxide with zinc and hydrochloric acid.
copper pyrites (copper), galena (lead), blende (zinc), cinnabar (mercury), &c. Of the sulphates we notice gypsum and anhydrite (calcium), barytes (barium) and kieserite (magnesium).
rend., 1869, 69, p. 169) obtained the sodium salt by the action of zinc on a concentrated solution of sodium bisulphite: Zn + 4NaHSO 3 = Na 2 S 2 O 4 + ZnSO 3 + Na 2 SO 3 + 2H 2 O, the salt being separated from the sulphites formed by fractional precipitation.
A pure zinc salt has been prepared by Nabl (Monats., 1899, 20, p. 679) by acting with zinc on a solution of sulphur dioxide in absolute alcohol, whilst H.
The principal manufactures are firearms, ironmongery, earthenware, woollen cloth, beer, stoneware, zinc goods, colours and salt; in the neighbourhood are iron and coal mines.
Michaels (Ber., 1897, 30, p. 1383) by distilling thebenol over zinc dust in a stream of hydrogen, or by the action of hydriodic acid and phosphorus at 220° C. on thebenol.
It is, however, nearly always found associated with zinc blende, and with calamine, although only in small quantities.
The chief minerals are sulphur, in the production of which Italy holds one of the first places, iron, zinc, lead; these, and, to a smaller extent, copper of an inferior quality, manganese and antimony, are successfully mined.
Both cuticularized and suberized membranes are insoluble in cuprammonia, and are colored yellow or brown in a soltition of chlor-iodide of zinc. It is probable that the corky or suberized cells do not contain any cellulose (Gilson, Wisselingh); whilst cuticularized cells are only modified in their outer layers, cellulose inner layers being still recognizable.
By the action of zinc methyl on ethyl borate, in the requisite proportions, boron trimethyl is obtained, thus :-2B(OC2H5)2+ 6Zn(CH 3) 2 =2B(CH 3) 3 +6Zn< OC2H5 as a colourless spontaneously inflammable gas of unbearable smell.
With bromine in acetic acid solution at ordinary temperature, nicotine yields a perbromide, C10H10Br2N20 HBr 3, which with sulphur dioxide, followed by potash, gives dibromcotinine, C10H10Br2N20, from which cotinine, C10H12N20, is obtained by distillation over zinc dust.
Dibromcotinine on hydrolysis yields oxalic acid, methylamine and 0-methyl pyridyl ketone: C10H10Br2N20+3H20+0= H2C204-ECH 3 NH 2 +C 5 H 4 N 000H 3 +2HBr; whilst dibromticonine yields methylamine, malonic acid and nicotinic acid: C10H8Br2N202+ 4H20=CH 3 NH 2 +CH 2 (CO 2 H) 2 +C 5 H 4 N CO 2 H+2HBr, or if heated with zinc and caustic potash, methylamine and pyridyl-ay-dioxybutyric acid.
The electromotive force of each cell is i 07 volts and the resistance 3 ohms. The Fuller bichromate battery consists of an outer jar containing a solution of bichromate of potash and sulphuric acid, in which a plate of hard carbon is immersed; in the jar there is also a porous pot containing dilute sulphuric acid and a small quantity (2 oz.) of mercury, in which stands a stout zinc rod.
CADMIUM (symbol Cd, atomic weight I12.4 (0=16)), a metallic element, showing a close relationship to zinc, with which it is very frequently associated.
It can be purified by solution in hydrochloric acid and subsequent precipitation by metallic zinc.
It is a basic oxide, dissolving readily in acids, with the formation of salts, somewhat analogous to those of zinc.
It is decomposed by heat into the oxide and water, and is soluble in ammonia but not in excess of dilute potassium hydroxide; this latter property serves to distinguish it from zinc hydroxide.
Thus if concentrated instead of dilute sulphuric acid acts upon zinc, the action takes place to a great extent not according to the equation given above, but according to the equation Zn +2H 2 SO 4 = ZnS04+S02+2 H20, sulphur dioxide and water being produced instead of hydrogen.
hydrogen during the action of zinc on dilute sulphuric acid) performs work equivalent to 580 cal.
One of the neighbouring mines, the Proprietary, is the richest in the world; gold is associated with the silver; large quantities of lead, good copper lodes, zinc and tin are also found.
Copper and zinc have also been found.
The harbour of Cagliari (along the north side of which runs a promenade called the Via Romo) is a good one, and has a considerable trade, exporting chiefly lead, zinc and other minerals and salt, the total annual value of exports amounting to nearly 12 million sterling in value.
Galena and other lead ores are abundant in veins in the limestone, but they are now only worked on a large scale at Mill Close, near Winster; calamine, zinc blende, barytes, calcite and fluor-spar are common.
Galena and other lead ores are abundant in veins in the limestone, but they are now only worked on a large scale at Mill Close, near Winster; calamine, zinc, blende, barytes, calcite and fluor-spar are common.
Besides lead, gypsum and zinc are raised, to a small extent; and for the quarrying of limestone Derbyshire is one of the principal English counties.
In the neighbourhood are lead, zinc and silver mines, and some 20 m.
The neighbourhood is rich in zinc and lead; and copper is also found.
Grapes, barley, esparto grass, dry figs, almonds and zinc are exported.
The mineral wealth of Carinthia is great, and consists in lead, iron, zinc and coal.
It is a strong acid, and dissolved in water decomposes carbonates and attacks iron and zinc.
The ores found here comprise silver-free galena, sulphate of zinc and calamine.
Zinc and hydrochloric acid reduce it to tri-thioformaldehyde (CH 2 S) 3 (A.
Ruthenium dichloride, RuC1 2, is obtained (in solution) by reducing the sesquichloride by sulphuretted hydrogen or zinc. It is stable in the cold.
Chromic acid oxidizes it to benzoic acid; zinc and acetic acid reduce it to cinnamic acid, C 6 H 5 CH:CH CO 2 H, whilst sodium amalgam reduces it to hydrocinnamic acid, C6H5 CH2 C02H.
He found, however, that chromic acid, which he had represented as Cr06, neutralized a base containing 3 the 3 The following symbols were also used by Bergman: W, V, " + ", which represented zinc, manganese, cobalt, bismuth, nickel, arsenic, platinum, water, alcohol, phlogiston.
4 The following are the symbols employed by Dalton: which represent in order, hydrogen, nitrogen, carbon, oxygen, phosphorus, sulphur, magnesia, lime, soda, potash, strontia, baryta, mercury; iron, zinc, copper, lead, silver, platinum, and gold were represented by circles enclosing the initial letter of the element.
The distribution of weight in chemical change is readily expressed in the form of equations by the aid of these symbols; the equation 2HC1+Zn =ZnCl2+H2, for example, is to be read as meaning that from 73 parts of hydrochloric acid and 65 parts of zinc, 136 parts of zinc chloride and 2 parts of hydrogen are produced.
The Egyptians obtained silver, iron, copper, lead, zinc and tin, either pure or as alloys, by smelting the ores; mercury is mentioned by Theophrastus (c. 300 B.C.).
The action of these acids on many metals was also studied; Glauber obtained zinc, stannic, arsenious and cuprous chlorides by dissolving the metals in hydrochloric acid, compounds hitherto obtained by heating the metals with corrosive sublimate, and consequently supposed to contain mercury.
Stromeyer detected a new metallic element, cadmium, in certain zinc ores; it was rediscovered at subsequent dates by other observers and its chemical resemblance to zinc noticed.
Richter in 1863, and of gallium, detected in certain zinc blendes by Lecoq de Boisbaudran in 1875.
If the substance does not melt but changes colour, we may have present: zinc oxide - from white to yellow, becoming white on cooling; stannic oxide - white to yellowish brown, dirty white on cooling; lead oxide - from white or yellowish-red to brownish-red, yellow on cooling; bismuth oxide - from white or pale yellow to orange-yellow or reddish-brown, pale yellow on cooling; manganese oxide - from white or yellowish white to dark brown, remaining dark brown on cooling (if it changes on cooling to a bright reddishbrown, it indicates cadmium oxide); copper oxide - from bright blue or green to black; ferrous oxide - from greyish-white to black; ferric oxide - from brownish-red to black, brownish-red on cooling; potassium chromate - yellow to dark orange, fusing at a red heat.
If the hot bead is colourless and remains clear on cooling, we may suspect the presence of antimony, aluminium, zinc, cadmium, lead, calcium and magnesium.
To the filtrate from the aluminium, iron and chromium precipitate, ammonia and ammonium sulphide are added; the precipitate may contain nickel, cobalt, zinc and manganese sulphides.
The next group precipitate may contain the white gelatinous aluminium hydroxide, the greenish chromium hydroxide, reddish ferric hydroxide, and possibly zinc and manganese hydroxides.
The next group may contain black nickel and cobalt sulphides, flesh-coloured manganese sulphide, and white zinc sulphide.
The solution with ammonium sulphide gives a white precipitate of zinc sulphide.
Neumann, who, in 1831, deduced from observations on many carbonates (calcium, magnesium, ferrous, zinc, barium and lead) that stoichiometric quantities (equimolecular weights) of compounds possess the same heat capacity.
The industries of the Lake District include slate quarrying and some lead and zinc mining, and weaving, bobbin-making and pencil-making.
Schwanert, Ann., 1860, 116, p. 2 57); by passing the vapour of dietbylamine through a redhot tube; by distilling succinimide with zinc dust (C. A.
Zinc dust and hydrochloric acid reduce pyrrol to pyrrolin (dihydropyrrol), C 4 H 6 NH, a liquid which boils at 90° C. (748 mm.); it is soluble in water and has strongly basic properties and an alkaline reaction.
It is remarkable that even a small addition of zinc-white (oxide of zinc) to the reddish varieties especially causes a considerable diminution in the intensity of the colour, while dilution with artificial precipitated sulphate of lime ("annalin") or sulphate of baryta ("blanc fix") acts pretty much as one would expect.
The objection that a copper plate shows signs of wear after a thousand impressions have been taken has been removed, since duplicate plates are readily produced by electrotyping, while transfers of copper engravings, on stone, zinc or aluminium, make it possible to turn out large editions in a printing-machine, which thus supersedes the slow-working hand-press.
Owing to the great weight of stones, their cost and their liability of being fractured in the press, zinc plates, and more recently aluminium plates, have largely taken the place of stone.
The manuscript maps intended to be produced by photographic processes upon stone, zinc or aluminium, are drawn on a scale somewhat larger than the scale on which they are to be printed, thus eliminating all those imperfections which are inherent in a pen-drawing.
A third method consists in placing the specimen within bibulous paper, and enclosing the whole between two plates of coarsely perforated zinc supported in a wooden frame.
The zinc plates are then drawn close together by means of straps, and suspended before a fire until the drying is effected.
They may also be prepared by the reduction of primary nitro compounds with stannous chloride and concentrated hydrochloric acid; by the reduction of unsaturated nitro compounds with minium amalgam or zinc dust in the presence of dilute acetic acid' Bouveault, Comptes rendus, 1902, 134, p. 1145):R2C:[[Chno 2 -R 2 C: Ch Nhoh - R 2 Ch Ch: Noh]], and by the action of alkyl iodides on the sodium salt of nitro-hydroxylamine (A.
Priestley, who obtained it by reducing nitrogen peroxide with iron, may be prepared by heating ammonium nitrate at 170-260° C., or by reducing a mixture of nitric and sulphuric acid with zinc. It is a colourless gas, which is practically odourless, but possesses a sweetish taste.
Bosnia is rich in minerals, including coal, iron, copper, chrome, manganese, cinnabar, zinc and mercury, besides marble and much excellent building stone.
The empire is rich in minerals, including gold, silver, lead, copper, iron, coal, mercury, borax, emery, zinc; and only capital is needed for successful exploitation.
Volta's cell consists essentially of two plates of different metals, such as zinc and copper, connected by an electrolyte such as a solution of salt or acid.
As an example of a fairly constant cell we may take that of Daniell, which consists of the electrical arrangement - zinc zinc sulphate solution copper sulphate solution copper, - the two solutions being usually separated by a pot of porous earthenware.
When the zinc and copper plates are connected through a wire, a current flows, the conventionally positive electricity passing from copper to zinc in the wire and from zinc to copper in the cell.
Zinc dissolves at the anode, an equal amount of zinc replaces an equivalent amount of copper on the other side of the porous partition, and the same amount of copper is deposited on the cathode.
This process involves a decrease in the available energy of the system, for the dissolution of zinc gives out more energy than the separation of copper absorbs.
But the internal rearrangements which accompany the production of a current do not cause any change in the original nature of the electrodes, fresh zinc being exposed at the anode, and copper being deposited on copper at the cathode.
Thus as long as a moderate current flows, the only variation in the cell is the appearance of zinc sulphate in the liquid on the copper side of the porous wall.
In spite of this appearance, however, while the supply of copper is maintained, copper, being more easily separated from the solution than zinc, is deposited alone at the cathode, and the cell remains constant.
Thus in the Daniell cell the dissolution of copper as well as of zinc would increase the loss in available energy.
But when zinc dissolves, the zinc ions carry their electric charges with them, and the liquid tends to become positively electrified.
Hence zinc can only dissolve when some more easily separable.
Plates of platinum and pure or amalgamated zinc are separated by a porous pot, and each surrounded by some of the same solution of a salt of a metal more oxidizable than zinc, such as potassium.
If sulphuric acid be added to the vessel containing the zinc, these conditions are unaltered and still no zinc is dissolved.
But, on the other hand, if a few drops of acid be placed in the vessel with the platinum, bubbles of hydrogen appear, and a current flows, zinc dissolving at the anode, and hydrogen being liberated at the cathode.
If the external electromotive force exceed that of the cell by ever so little, a current flows in the opposite direction, and all the former chemical changes are reversed, copper dissolving from the copper plate, while zinc is deposited on the zinc plate.
When one gramme of zinc is dissolved in dilute sulphuric acid, 1670 thermal units or calories are evolved.
Hence for the electrochemical unit of zinc or 0.003388 gramme, the thermal evolution is 5.66 calories.
The concentration of the simple copper ions is then so much diminished that the copper plate becomes an anode with regard to zinc. Thus the cell - copper I potassium cyanide solution I potassium sulphate solution - zinc sulphate solution I zinc - gives a current which carries copper into solution and deposits zinc. In a similar way silver could be made to act as anode with respect to cadmium.
Hence, if we assume that, in the Daniell's cell, the temperature coefficients are negligible at the individual contacts as well as in the cell as a whole, the sign of the potential-difference ought to be the same at the surface of the zinc as it is at the surface of the copper.
Since zinc goes into solution and copper comes out, the electromotive force of the cell will be the difference between the two effects.
By both these methods the single potential-differences found at the surfaces of the zinc and copper have opposite signs, and the effective electromotive force of a Daniell's cell is the sum of the two effects.
It is a centre of the iron and steel industries, producing principally cast steel, cast iron, iron pipes, wire and wire ropes, and lamps, with tin and zinc works, coal-mining, factories for carpets, calcium carbide and paper-roofing, brickworks and breweries.
Another very excellent method of vulcanizing cut sheet goods consists in placing them in a solution of the polysulphides of calcium at a temperature of 140° C. Rubber employed for the manufacture of cut sheets is often coloured by such pigments as vermilion, oxide of chromium, ultramarine, orpiment, antimony, lamp black, or oxide of zinc, incorporation being effected either by means of the masticator or by a pair of rollers heated internally by steam, and so geared as to move in contrary directions at unequal FIG.
For this reason the acid copper-bath is not used for iron or zinc objects, a bath containing copper cyanide or oxide dissolved in potassium cyanide being substituted.
Zinc is commonly deposited by electrolysis on iron or steel goods which would ordinarily be "galvanized," but which for any reason may not conveniently be treated by the method of immersion in fused zinc. The zinc cyanide bath may be used for small objects, but for heavy goods the sulphate bath is employed.
Sherard Cowper Coles patented a process in which, working with a high current density, a lead anode is used, and powdered zinc is kept suspended in the solution to maintain the proportion of zinc in the electrolyte, and so to guard against the gradual acidification of the bath.
The electro-deposition of brass-mainly on iron ware, such as bedstead tubes-is now very widely practised, the bath employed being a mixture of copper, zinc and potassium cyanides, the proportions of which vary according to the character of the brass required, and to the mode of treatment.
The colour depends in part upon the proportion of copper and zinc, and in part upon the current density, weaker currents tending to produce a redder or yellower metal.
An authority on precious stones, and especially the diamond, he succeeded in artificially making some minute specimens of the latter gem; and on the discovery of radium he was one of the first to take up the study of its properties, in particular inventing the spinthariscope, an instrument in which the effects of a trace of radium salt are manifested by the phosphorescence produced on a zinc sulphide screen.
Thus, a mixture of lead sulphate (45%) and oxide (44%) with some sulphide (8%), zinc and carbonaceous matter, is agglomerated by a heap-roast and then smelted in a slag-eye furnace with grey slag from the ore-hearth.
This is drawn off, cooled and filtered, and forms a white paint of good body, consisting of about 65% lead sulphate, 26% lead oxide, 6% zinc oxide and 3% other substances.
one that is a medium coarse, contains 12-15% lead, not over 5% zinc,`and makes under 5% matte.
In 1842 Karsten discovered that lead could be desilverized by means of zinc. His invention, however, only took practical form in1850-1852through the researches of Parkes, who showed how the zinc-silver-lead alloy formed could be worked and the desilverized lead freed from the zinc it had taken up. In the Parkes process only 5% of the original lead need be cupelled.
The effect of the two processes on the purity of the market lead is clearly shown by the two following analyses by Hampe, which represent lead from Lautenthal in the Harz Mountains, where the Parkes process replaced that of Pattinson, the ores and smelting process remaining practically the same: - It is absolutely necessary for the success of the Parkes process that the zinc and lead should contain only a small amount of impurity.
When zinc is placed on the lead (heated to above the melting-point of zinc), liquefied and brought into intimate contact with the lead by stirring, gold, copper, silver and lead will combine with the zinc in the order given.
of zinc, all the gold and copper and some silver and lead will be alloyed with the zinc to a so-called gold - or copper - crust, and the residual lead saturated with zinc. By removing from the surface of the lead this first crust and working it up separately (liquating, retorting and cupelling), dore silver is obtained.
By the second addition of zinc most of the silver will be collected in a saturated zinc-silver-lead crust, which, when worked up, gives fine silver.
As this complete desilverization is only possible by the use of an excess of zinc, the unsaturated zinc-silver-lead alloy is put aside to form part of the second zincking of the next following charge.
A zincking takes 5-6 hours;1 1 5-2.5% zinc is required for desilverizing.
The liquated zinc-silver-lead crust contains 5-10% silver, 30-40% zinc and 65-50% lead.
Before it can be cupelled it has to be freed from most of the zinc, which is accomplished by distilling in a retort made of a mixture similar to that of the plumbago crucible.
The distillation of 1000 lb charge lasts 5-6 hours, requires 500-600 lb coke or 30 gallons reduced oil, and yields about to% metallic zinc and I% blue powder - a mixture of finely-divided metallic zinc and zinc oxide.
About 60% of the zinc used in desilverizing is recovered in a form to be used again.
The desilverized lead, which retains o 6-0.7% zinc, has to be refined before it is suited for industrial use.
The zinc and some lead are oxidized; part of the zinc passes off with the fumes, part is dissolved by the litharge, forming a melted mixture which is skimmed off and reduced in a blast-furnace or a reverberatory smelting furnace.
In the kettle covered with a hood the zinc is oxidized by means of dry steam, and incidentally some lead by the air which cannot be completely excluded.
A yellowish powdery mixture of zinc and lead oxides collects on the lead; it is skimmed off and sold as paint.
"Pewter" (q.v.) may be said to be substantially an alloy of the same two metals, but small quantities of copper, antimony and zinc are frequently added.
Here compounds of divalent lead have not yet been obtained; by acting with zinc ethide on lead chloride, lead tetraethide, Pb(C 2 IH Q) 4, is obtained, with the separation of metallic lead.
It is formed when the vapours of toluene, stilbene, dibenzyl, ortho-ditolyl, or coumarone and benzene are passed through a red-hot tube; by distilling morphine with zinc dust; and, with anthracene, by the action of sodium on ortho-brombenzyl bromide (C. L.
The reaction is a general one for all aldehydes with zinc methyl and zinc ethyl, but not with the higher zinc alkyls.
It is readily polymerized, small quantities of hydrochloric acid, zinc chloride, carbonyl chloride, &c. converting it, at ordinary temperatures, into paraldehyde, (C 2 H 4 0) 3, a liquid boiling at 124° C. and of specific gravity oï¿½998 (15° C.).
Its chief mineral products are coal, nitre, sulphur, alum, soda, saltpetre, gypsum, porcelain-earth, pipe-clay, asphalt, petroleum, marble and ores of gold, silver, mercury, copper, iron, lead, zinc, antimony, cobalt and arsenic. The principal mining regions are Zsepes-Giimor in Upper Hungary, the Kremnitz-Schemnitz district, the Nagybanya district, the Transylvanian deposits and the Banat.
Small up to the beginning of the 19th century, Holywell has increasingly prospered, thanks to lime quarries, lead, copper and zinc mines, smelting works, a shot manufactory, copper, brass, iron and zinc works; brewing, tanning and mineral water, flannel and cement works.
The mother liquor includes generally more or less of nickel, cobalt, zinc and other heavy metals, which, as Wailer showed, can be removed as insoluble sulphides by the addition of ammonium sulphide; uranium, under the circumstances, is not precipitated by this reagent.
According to Stolba, beautiful crystals of pure tin can be obtained as follows: A platinum basin, coated over with wax or paraffin outside, except a small circle at the very lowest point, is placed on a plate of amalgamated zinc, lying on the bottom of a beaker, and is filled with a solution of pure stannous chloride.
A strip of metallic zinc when placed in a solution of stannous chloride precipitates the tin in crystals and takes its place in the solution.
87, p. 325) synthesized it by acting with benzoyl chloride on zinc glycocollide.
When heated with zinc dust, it yields ethylene and water.
The mineral wealth is great, including copper, tin, lead, zinc, iron and especially coal.
Bernthsen (Ann., 1884, 224, p. 1) condensed diphenylamine with fatty acids, in the presence of zinc chloride.
Fischer); by heating salicylic aldehyde with aniline and zinc chloride to 260° C. (R.
Mohlau, Ber., 1886, 1 9, p. 2 45 2); and by distilling acridone over zinc dust (C. Graebe, Ber., 1892, 2 5, p. 1735).
The newer glasses, on the other hand, contain a much wider variety of chemical constituents, the most important being the oxides of barium, magnesium, aluminium and zinc, used either with or without the addition of the bases already named in reference to the older glasses, and - among acid bodies - boric anhydride (B20 3) which replaces the silica of the older glasses to a varying extent.
The materials are generally used in the form either of oxides (lead, zinc, silica, &c.) or of salts readily decomposed by heat, such as the nitrates or carbonates.
The oxides of lead, barium, zinc and antimony are found perceptibly to retard the rays.
Wohler, Ann., 1856, 97, p. 266; 1857, 102, p. 382); by heating silica with magnesium in the presence of zinc (L.
The organic derivatives of silicon resemble the corresponding carbon compounds except in so far that the silicon atom is not capable of combining with itself to form a complex chain in the same manner as the carbon atom, the limit at present being a chain of three silicon atoms. Many of the earlier-known silicon alkyl compounds were isolated by Friedel and Crafts and by Ladenburg, the method adopted consisting in the interaction of the zinc alkyl compounds with silicon halides or esters of silicic acids.
Triethyl silicol, (C2H5),Si OH, is a true alcohol, obtained by condensing zinc ethyl with silicic ester, the resulting substance of composition, (C2H5)3 SiOC2H51 with acetyl chloride yielding a chloro-compound (C2H5)3SiC1, which with aqueous ammonia yields the alcohol.
Many are found as minerals, the more important of such naturally occurring carbonates being cerussite (lead carbonate, PbC03), malachite and azurite (both basic copper carbonates), calamine (zinc carbonate, ZnCO 3), witherite (barium carbonate, BaCO 3), strontianite (strontium carbonate, SrC03), calcite (calcium carbonate, CaC03), dolomite (calcium magnesium carbonate, CaCO 3 MgCO 3), and sodium carbonate, Na 2 CO 3.
It is easily broken down by many substances (aluminium chloride, zinc chloride, &c.) into ethyl chloride and carbon dioxide.
The crystals belong to the following systems: regular system - silver, gold, palladium, mercury, copper, iron, lead; quadratic system - tin, potassium; rhombic system - antimony, bismuth, tellurium, zinc, magnesium.
Antimony, bismuth and zinc exhibit a very distinct crystalline structure: a bar-shaped ingot readily breaks, and the crystal faces are distinctly visible on the fracture.
A bar of zinc, for instance, as obtained by casting, is very brittle; but when heated to 100° or 150° C. it becomes sufficiently plastic to be rolled into the thinnest sheet or to be drawn into wire.
Distillable at red heats: cadmium, alkali metals, zinc, magnesium.
Water, at ordinary or slightly elevated temperatures, is decomposed more or less readily, with evolution of hydrogen gas and formation of a basic hydrate, by (I) potassium (formation of KHO), sodium (NaHO), lithium (LiOH), barium, strontium, calcium (BaH 2 O 2, &c.); (2) magnesium, zinc, manganese (MgO 2 H 2, &c.).
Of the rest, the following are readily oxidized by steam at a red heat, with formation of hydrogen gas - zinc, iron, cadmium, cobalt, nickel, tin.
The same holds for the following group (A): [manganese, zinc, magnesium] iron, aluminium, cobalt, nickel, cadmium.
Iron, zinc, cadmium, also tin under certain conditions, reduce the dilute acid, partially at least, to nitrous oxide, N 2 0, or ammonium nitrate, NH4N03.
The most important of these are aluminium and zinc, which are converted into aluminate, Al(OK,Na) 3, and zincate, Zn(OK,Na) 2, respectively.
Potassium, for example, yields peroxide, K202 or K204; sodium gives Na202; the barium-group metals, as well as magnesium, cadmium, zinc, lead, copper, are converted into their monoxides MeO.
The following, though volatile at higher temperatures, are not volatilized at dull redness: KC1, NaCI, LiC1, NiC1 2, CoC1 2, MnC1 2, ZnCl 2, MgCl 2, PbCl 2, AgCI, the chlorides of potassium, sodium, lithium, nickel, cobalt, manganese, zinc, magnesium, lead, silver.
There are also iron, zinc and chemical manufactures, and the cultivation of agricultural seeds is carried on.
On warming the osazone with hydrochloric acid the phenylhydrazine residues are removed and an osone results, which on reduction with zinc and acetic acid gives a ketose.
A ketose may also be obtained by reducing the osazone with zinc and acetic to an osamine, which with nitrous acid gives the ketose: R R R C :N NHPh.
It also results on condensing acetylene, and on reducing phenylacetylene by zinc dust and acetic acid.
ZINC, a metallic chemical element; its symbol is Zn, and atomic weight 65.37 (0= 16).
Zinc as a component of brass (XaXKOs, 6pei-XaXKos) had currency in metallurgy long before it became known as an individual metal.
Pliny explicitly speaks of a mineral Katiµ€ia or cadmic as serving for the conversion of copper into aurichalcum, and says further that the deposit (of zinc oxide) formed in the brass furnaces could be used instead of the mineral.
Moreover, zinc and bismuth were confused, and the word spiauter (the modern spelter) was indiscriminately given to both these metals.
From his account it is quite clear that that metal was zinc, but he did not recognize it as the metal of calamine.
It is not known to whom the discovery of isolated zinc is due; but we do know that the art of zinc-smelting was practised in England from about 1730.
Zinc does not occur free in nature, but in combination it is widely diffused.
Second in importance is the carbonate, calamine (q.v.) or zinc spar, which at one time was the principal ore; it almost invariably contains the carbonates of cadmium, iron, manganese, magnesium and calcium, and may be contaminated with clay, oxides of iron, galena and calcite; "white calamine" owes its colour to much clay; "red calamine" to admixed iron and manganese oxides.
Other zinc minerals are willemite, Zn 2 SiO 4, hydrozincite or zinc bloom, ZnCO 3.2Zn(OH)2, zincite or red zinc ore, ZnO, and franklinite, 3(Fe,Zn)0 (Fe,Mn) 2 0 3 .
Metallurgy The principles underlying the extraction of zinc may be summarized as: (I) the ore is first converted into zinc oxide; (2) the oxide is distilled with carbon and the distillate of metallic zinc condensed.
Oxide of zinc, like most heavy metallic oxides, is easily reduced to the metallic state by heating it to redness with charcoal; pure red zinc ore may be treated directly; and the same might be done with pure calamine of any kind, because the carbon dioxide of the zinc carbonate goes off below redness and the silica of zinc silicate only retards, but does not prevent, the reducing action of the charcoal.
Zinc blende, however, being zinc sulphide, is not directly reducible by charcoal; but it is easy to convert it into oxide by roasting: the sulphur goes off as sulphur dioxide whilst the zinc remains in the (infusible) form of oxide, ZnO.
In practice, however, we never have to deal with pure zinc minerals, but with complex mixtures, which must first of all be subjected to mechanical operations, to remove at least part of the gangue, and if possible also of the heavy metallic impurities.
As ores of zinc are usually shipped before smelting from widely separated places - Sweden, Spain, Algiers, Italy, Greece, Australia and the Rocky Mountains region of North America - it is important that they be separated from their mixtures at the mines.
The difficulty in separating zinc blende from iron pyrites is well known, and probably the most elaborate ore-dressing works ever built have been designed with this end in view.
Here very clean non-magnetic concentrate of willemite, which is an anhydrous zinc silicate and a very highgrade zinc ore, is separated from an intimate mixture of willemite, zincite and franklinites, with calcite and some manganese silicates.
The magnetic concentrates contain enough zinc to be well adapted to the manufacture of zinc oxide.
Neither mechanical nor magnetic concentration can effect much in the way of separation when, as in many complex ores, carbonates of iron, calcium and magnesium replace the isomorphous zinc carbonate, when some iron sulphide containing less sulphur than pyrites replaces zinc sulphide, and when gold and silver are contained in the zinc ore itself.
of zinc, in which the zinc alone, estimated at 2d.
of zinc, but the dressed zinc ore as sold ranges from 45 to 62 per cent.
of zinc. This region now furnishes the bulk of the ore required by the smelters of Illinois, Missouri and Kansas.
The ore, even if it is not blende, must be roasted or calcined in order to remove all volatile components as completely as possible, because these, if allowed to remain, would carry away a large proportion of the zinc vapour during the distillation.
If the zinc is present as blende, this operation offers considerable difficulties, because in the roasting process the zinc sulphide passes in the first instance into sulphate, which demands a high temperature for its conversion into oxide.
For the desulphurization of zinc blende where it is not intended to collect and save the sulphur there are many mechanical kilns, generally classified as straight-line, horse-shoe, turret and shaft kilns; all of these may be made to do good work on moderately clean ores which do not melt at the temperature of desulphurization.
of zinc enough sulphur is liberated to produce one ton of strong sulphuric acid, and unless this is collected not only are poisonous gases discharged, but the waste is considerable.
The zinc vapour produced descends through the pipe and condenses into liquid zinc, which is collected in a ladle held under the outlet end of the pipe.
After a time the flame becomes dazzling white, showing that zinc vapour is beginning to escape.
The iron adapters are now slipped on, and left on for two hours, when, as a matter of experience, a considerable amount of zinc has gone out of the retort, the greater part into the fire-clay adapter, the rest into the iron cone.
The contents of the iron recipient consist of a powdery mixture of oxide and metal, which is added to the next charge, except what is put aside to be sold as "zinc dust."
Through an orifice in the outlet pipe (which is closed during the distillation by a loose plug) a hot iron rod can be introduced from time to time to clear away any solid zinc that may threaten to obstruct it.
As soon as the outlet pipe has become sufficiently hot the zinc flows through it and collects in conveniently placed receptacles.
The distillate consists of a conglomerate of drops ("drop zinc").
When hydraulic pressure to the amount of 2000 to 3000 lb per square inch is applied, the saving is unquestioned, since less time is required to dry the pressed retort, its life in the furnaces is longer, its absorption of zinc is less, and the loss of zinc by passage through its walls in the form of vapour is reduced.
The men who charge and empty the retorts, those who draw and cast the metal, and those who keep the furnace in repair, need not know anything about the making or using of gas, and the men who make the gas need not know anything about a zinc furnace.
The specific effects of different impurities on the physical properties of zinc have only been imperfectly studied.
Fortunately, however, the small amounts of any of them that are likely to be found in commercial zinc are not for most purposes very deleterious.
Grades of commercial zinc are usually based on selected ores, and brands, when they mean anything, usually mean that the metal is made from certain ores.
Chemical control of the metal purchased is not nearly as common as it should be, and the refining of zinc is at best an imperfect operation.
To obtain the metal chemically pure a specially prepared pure oxide or salt of zinc is distilled.
A redistilled zinc, from an ordinarily pure commercial zinc, is often called chemically pure, but redistillation is seldom practised except for the recovery of zinc from galvanizer's dross and from the skimmings and bottoms of the melting furnaces of zinc rolling mills.
A bath, even of very impure zinc, is allowed to stand at about the temperature of the melting-point of the metal for forty-eight or more hours, whereupon the more easily oxidizable impurities can be largely removed in the dross at the top, the heavier metals such as lead and iron settling towards the bottom.
This method is rarely practised except by the rollers of zinc. A certain amount of refined zinc can be dipped from the furnace; a further amount, nearly free from iron, can be liquated out of the ingots cast from the bottom of the bath in a subsequent slow remelting, and it is sometimes possible to eliminate a zinciferous lead which collects in the sump of the furnace.
Owing to the fact that at temperatures between its melting and boiling point zinc has a strong affinity for iron, it is often contaminated by the scraper while being drawn from the condenser, as is shown by the fact that the scraper wears away rapidly.
Some brassfounders break from a single ingot the quantity of zinc required to produce the amount of brass they wish to compound in one crucible, but when perfect uniformity is desired the importance of remelting the zinc on a large scale cannot be too strongly emphasized.
The deposition of pure zinc is beset with many difficulties.
Zinc being more electro-positive even than nickel, all the heavy metals must be removed before its deposition is attempted.
The cause of the spongy deposit is variously explained, some (Siemens and Halske) ascribing it to the existence of a compound of zinc and hydrogen, and others, among whom are G.
Borchers, trace it to the presence of oxide, produced, for example, either by the use of a solution containing a trace of basic salt of zinc (to prevent which the bath should be kept just - almost imperceptibly - acid), or by the presence of a more electro-negative metal, which, being co-deposited, sets up local action at the expense of the zinc. Many processes have been patented, the ore being acted upon by acid, and the resulting solution treated, by either chemical or electrolytic means, for the successive removal of the other heavy metals.
The pure solution of zinc is then electrolysed.
Ashcroft patented a process of dealing with complex ores of the well-known Broken Hill type, containing sulphides of silver, lead and zinc, but the system was abandoned after a long trial on a practical scale.
2 lb of zinc in the form of sulphate, and z to 4 oz.
Nahnsen's process, with an electrolyte containing alkali-metal sulphate and zinc sulphate, has been used in Germany, and a process invented by Dieffenbach has also been tried in that country.
Borchers and others deposit zinc from the fused chloride.
Properties Zinc is a bluish-white metal, showing a high lustre when freshly fractured.
If zinc be cast into a mould at a red heat, the ingot produced is laminar and brittle; if cast at just the fusing-point, it is granular and sufficiently ductile to be rolled into sheet at the ordinary temperature.
According to some authorities, pure zinc always yields ductile ingots.
The specific gravity of zinc cannot be expected to be perfectly constant; according to Karsten, that of pure ingot is 6.915, and rises to 7.191 after rolling.
Compact zinc is bluish white; it does not tarnish much in the air.
If zinc be heated to near its boiling-point, it catches fire and burns with a brilliant light into its powdery white oxide, which forms a reek in the air (lana philosophica, " philosopher's wool").
A rod of perfectly pure zinc, when immersed in dilute sulphuric acid, is so very slowly attacked that there is no visible evolution of gas; but, if a piece of platinum, copper or other more electro-positive metal be brought into contact with the zinc, it dissolves readily, with evolution of hydrogen and formation of the sulphate.
Cold dilute nitric acid dissolves zinc as nitrate, with evolution of nitrous oxide.
Zinc is also soluble in soda and potash solutions, but not in ammonia.
Zinc is largely used for "galvanizing" iron, sheets of clean iron being immersed in a bath of the molten metal and then removed, so that a coat of zinc remains on the iron, which is thereby protected from atmospheric corrosion.
Zinc forms only one oxide, ZnO, from which is derived a wellcharacterized series of salts.
It is chemically related to cadmium and mercury, the resemblance to cadmium being especially well marked; one distinction is that zinc is less basigenic. Zinc is capable of isomorphously replacing many of the bivalent metals - magnesium, manganese, iron, nickel, cobalt and cadmium.
Zinc oxide, ZnO, is maufactured for paint by two processes - directly from the ore mixed with coal by volatilization on a grate, as in the Wetherill oxide process, and by oxidizing the vapour given off by a boiling bath of zinc metal.
It is also manufactured by the latter process from the metallic zinc liquated out of galvanizer's dross.
Zn(OK)2] Zinc oxide is used in the arts as a white pigment (zinc white); it has not by any means the covering power of white lead, but offers the advantages of being non-poisonous and of not becoming discoloured in sulphuretted hydrogen.
Zinc hydroxide, Zn (OH) 2, is prepared as a gelatinous precipitate by adding a solution of any zinc salt to caustic potash.
A solution of zinc chloride is easily produced from the metal and hydrochloric acid; it cannot be evaporated to dryness without considerable decomposition of the hydrated salt into oxychloride and hydrochloric acid, but it may be crystallized as ZnC1 2 H 2 O.
At a boiling heat, zinc chloride dissolves in any proportion of water, and highly concentrated solutions, of course, boil at high temperatures; hence they afford a convenient medium for the maintenance of high temperatures.
Zinc chloride solution readily dissolves the oxide with the formation of oxychlorides, some of which are used as pigments, cements and for making artificial teeth.
Zinc bromide, ZnBr 2, and Zinc iodide, Zn12, are deliquescent solids formed by the direct union of their elements.
Zinc sulphide, ZnS, occurs in nature as blende (q.v.), and is artificially obtained as a white precipitate by passing sulphuretted hydrogen into a neutral solution of a zinc salt.
Zinc sulphate, ZnS04+7H20, or white vitriol, is prepared by dissolving the metal in dilute sulphuric acid.
If care be taken to keep the zinc in excess, the solution will be free from all foreign metals except iron and perhaps manganese.
A green pigment known as Rinmann's green is prepared by mixing I oo parts of zinc vitriol with 2.5 parts of cobalt nitrate and heating the mixture to redness, to produce a compound of the two oxides.
Zinc sulphate, like magnesium sulphate, unites with the sulphates of the potassium metals and of ammonium into crystalline double salts, ZnS04 R2S04-+-6H20, isomorphous with one another and the magnesium salts.
Zinc carbonate, ZnCO 3, occurs in nature as the mineral calamine (q.v.), but has never been prepared artificially, basic carbonates, ZnCO 3 .xZn(OH) 2, where x is variable, being obtained by precipitating a solution of the sulphate or chloride with sodium carbonate.
To obtain a product free of Cl or S04, there must be an excess of alkali and the zinc salt must be poured into the hot solution of the carbonate.
Of zinc phosphates we notice the minerals hopeite, Zn.
- From neutral solutions of its salts zinc is precipitated by sulphuretted hydrogen as sulphide, ZnS - a white precipitate, soluble, but by no means readily, in dilute mineral acids, but insoluble in acetic acid.
Zinc may be quantitatively estimated by precipitating as basic carbonate, which is dried and ignited to zinc oxide.
It may also be precipitated as zinc ammonium phosphate, NH4ZnP04, which is weighed on a filter tared at 100°.
Pharmacology And Therapeutics Of Zinc Compounds Zinc chloride is a powerful caustic, and is prepared with plaster of Paris in the form of sticks for destroying warts, &c. Its use for this purpose at the present day is, however, very rare, the knife or galvanocautery being preferred in most cases.
Numerous other salts of zinc, used in medicine, are of value as containing this metal.
Lotio Rubra, the familiar "Red Lotion," a solution of zinc sulphate, is widely used in many catarrhal inflammations, as of the ear, urethra, conjunctiva, &c. There are also innumerable ointments.
- For the history of zinc see Bernard Neumann, Die Metalle (1904); A.
For the metallurgy see Walter Renton Ingalls, The Metallurgy of Zinc and Cadmium; Production and Properties of Zinc; A.
Lodin, Metallurgie du zinc (1905); C. Schnabel, Handbook of Metallurgy, English translation by H.
It may be prepared by fusion of ortho-toluene sulphonic acid with potash; by the action of phosphorus pentoxide on carvacrol; or by the action of zinc chloride on camphor.
Lead, zinc and other metals have also been reduced in this manner.
Anthracene has also been obtained by heating ortho-tolylphenyl ketone with zinc dust C6H4(CH CH =H20+C6H4 I)C6H4.
At a red heat rutile is produced, at the boiling point of zinc brookite, and of cadmium anatase.
Wallach, Ber., 1881, 14, P. 421); by the action of reducing agents on nitroparaffins; by the action of zinc and hydrochloric acid on aldehyde ammonias (German Patent 73,812); by the reduction of the phenylhydrazones and oximes of aldehydes and ketones with sodium amalgam in the presence of alcohol and sodium acetate (J.
Zinin), zinc and hydrochloric acid (A.
Tafel, Ber., 1886, 19, p. 1924), by distilling the amido-acids with lime, by heating phenols with zinc chloride ammonia (V.
The secondary amines may be of two types-namely,the purely aromatic amines, and the mixed secondary amines, which contain an aromatic residue and an alkyl group. The purely aromatic amines result upon heating the primary amines with their hydrochlorides, and, in some cases, by heating a phenol with a primary amine and anhydrous zinc chloride.
The aromatic amine resembling the aliphatic amines is benzylamine, C 6 H 5 ï¿½CH 2 ï¿½NH 2, which may be prepared by reducing benzonitrile in alcoholic solution by means of zinc and acetic acid (0.
When heated with monobasic saturated acids and zinc chloride it yields acridines.
- Coal has been discovered in the Khmir ("Kroumir") country, but the principal mines at present worked in Tunisia are those of copper, lead and zinc. Zinc is chiefly found in the form of calamine.
The principal exports are olive oil, wheat, esparto grass, barley, sponges, dates, fish (especially tunny), hides, horses, wool, phosphates, copper, zinc and lead.
Within these limits are to be found most of the minerals known - gold, silver, quicksilver, copper, lead, zinc, iron, manganese, wolfram, bismuth, thorium, vanadium; mica, coal, &c. On or near the coast are coal, salt, sulphur, borax, nitrates and petroleum.
Practically any vessel may serve as a receiver - test tube, flask, beaker, &c. If noxious vapours come over, it is necessary to have an air-tight connexion between the condenser and receiver, and to pro vide the latter with an outlet tube leading to an absorption column or other contrivance in which the vapours are taken up. If the substances operated upon decompose when heated in air, as, for example, the zinc alkyls which inflame, the air within the apparatus is replaced by some inert gas, e.g.
Lead is of frequent occurrence, and indeed the area through which copper, silver, lead, tin and zinc are distributed in sufficient quantities to make mining answer, comprises at least 80,000 sq.
There are also present small quantities of arsenic and antimony, and zinc is found generally as a mere trace, but sometimes reaching to 6%.
Copper, tin, lead and zinc, mixed in various proportions by different experts, are the ingredients, and the beautiful golden hues and glossy texture of the surface are obtained by patina-producing processes, in which branch of metal-work the Japanese show altogether unique skill.
The mineral wealth of Baden is not great; but iron, coal, zinc and lead of excellent quality are produced, and silver, copper, gold, cobalt, vitriol and sulphur are obtained in small quantities.
Its other mineral resources include graphite, copper, zinc, lead, salt, alum, potter's clay, marble and good mill and building stones.
Hermite, which consisted in the production of bleach-liquors by the electrolysis (according to the 1st edition of the 1884 patent) of magnesium or calcium chloride between platinum anodes carried in wooden frames, and zinc cathodes.
Rotating zinc cathodes were used, with scrapers to prevent the accumulation of a layer of insoluble magnesium compounds, which would otherwise increase the electrical resistance beyond reasonable limits.
On treatment with zinc and alkyl iodides or with zinc alkyls they are converted into esters of hydroxy-dialkyl acetic acids.
If we melt copper and add to it about 30% of zinc, or 20 of tin, we obtain uniform liquids which when solidified are the well-known substances brass and bell-metal.
But it is not permissible to call brass a chemical compound, for we can largely alter its percentage composition without the substance losing the properties characteristic of brass; the properties change more or less continuously, the colour, for example, becoming redder with decrease in the percentage of zinc, and a paler yellow when there is more zinc. The possibility of continuously varying the percentage composition suggests analogy between an alloy and a solution, and A.
For example, if vapours of the volatile metals cadmium, zinc and magnesium are allowed to act on platinum or palladium, alloys are produced.
Fromm have shown that alloys may be precipitated from dilute solutions by zinc, cadmium, tin, lead and copper.
Thus a strip of zinc plunged into a solution of silver sulphate, containing not more than 0.03 gramme of silver in the litre, becomes covered with a flocculent precipitate which is a true alloy of silver and zinc, and in the same way, when copper is precipitated from its sulphate by zinc, the alloy formed is brass.
A very similar fact, that brass may be formed by electrodeposition from a solution containing zinc and copper, has long been known.
Debray in the case of rhodium, iridium and ruthenium, which evolve heat when they are dissolved in zinc. When the solution of the rhodium-zinc alloy is treated with hydrochloric acid, a residue is left which undergoes a change with explosive violence if it be heated in vacuo to 400°.
The presence of minute quantities of cadmium, lead, bismuth, antimony, arsenic, tin, tellurium and zinc renders gold brittle, 2 ' 0 15th part of one of the three metals first named being sufficient to produce that quality.
Copper and zinc increase the volatility far more than lead, while the greatest volatility is induced, according to T.
Magnetic pyrites, copper pyrites, zinc blende and arsenical pyrites are other and less important examples, the last constituting the gold ore formerly worked in Silesia.
They may be said to possess a series of bronzes, in which gold and silver replace tin and zinc, all these alloys being characterized by patina having a wonderful range of tint.
Gold and Zinc.-When present in small quantities zinc renders gold TABLE II.-Gold brittle, but it may be added to gold in larger quantities without destroying the ductility of the precious metal; Peligot proved that a triple alloy of gold, copper and zinc, which contains 5.8% of the lastnamed, is perfectly ductile.
The alloy of II parts gold and i part of zinc is, however, stated to be brittle.
- This process depends upon the solubility of gold in a dilute solution of potassium cyanide in the presence of air (or some other oxidizing agent), and the subsequent precipitation of the gold by metallic zinc or by.
The strengths employed depend also upon the mode of precipitation adopted, stronger solutions (up to 0.25% KCN) being used when zinc is the precipitant.
In the Transvaal the operation occupies 32 to 4 days for fine sands, and up to 14 days for coarse sands; the quantity of cyanide per ton of tailings varies from 0.26 to 0.28 lb, for electrolytic precipitation, and o 5 lb for zinc precipitation.
The precipitation is effected by zinc in the form of bright turnings, or coated with lead, or by electrolysis.
According to Christy, the precipitation with zinc follows equations for 2 according as potassium cyanide is present or not: (1) 4 KAu(CN)2+4Zn+2H20=2Zn(CN)2+ K 2 Zn(CN) 4 +Zn(OK) 2 +4H+4Au; (2) 2KAu (CN) 2 +3Zn+4KCN+2H 2 0 = 2K 2 Zn(CN) 4 +Zn(OK) 2 +4H+2Au; one part of zinc precipitating 3.1 parts of gold in the first case, and 2.06 in the second.
It may be noticed that the potassium zinc cyanide is useless in gold extraction, for it neither dissolves gold nor can potassium cyanide be regenerated from it.
In the wider compartments are placed sieves having sixteen holes to the square inch and bearing zinc turnings.
The slime is cleaned out fortnightly or monthly, the zinc turnings being cleaned by rubbing and the supernatant liquor allowed to settle in the precipitating boxes or in separate vessels.
The slime so obtained consists of finely divided gold and silver (5-5 0%), zinc (30-60%), lead (io%), carbon (io%), together with tin, copper, antimony, arsenic and other impurities of the zinc and ores.
This dissolves out the zinc. Lime is added to bring down the gold, and the sediment, after washing and drying, is fused in graphite crucibles.
Its advantages over the zinc process are that the deposited gold is purer and more readily extracted, and that weaker solutions can be employed, thereby effecting an economy in cyanide.
The Carpathian system is richer in metallic ores than any other mountain system of Europe, and contains large quantities of gold, silver, copper, iron, lead, coal, petroleum, salt, zinc, &c., besides a great variety of useful mineral.
0-Naphthylamine is prepared by heating 13-naphthol with zinc chloride-ammonia to 200-210° (V.
Its elementary nature was imperfectly understood; and the impure specimens obtained by the early chemists explain, in some measure, its confusion with tin, lead, antimony, zinc and other metals; in 1595 Andreas Libavius confused it with antimony, and in 1675 Nicolas Lemery with zinc. These obscurities began to be finally cleared up with the researches of Johann Heinrich Pott (1692-1777), a pupil of Stahl, published in his Exercitationes chemicae de Wismutho (1769), and of N.
It is precipitated as the metal from solutions of its salts by the metals of the alkalis and alkaline earths, zinc, iron, copper, &c. In its chemical affinities it resembles arsenic and antimony; an important distinction is that it forms no hydrogen compound analogous to arsine and stibine.
The metal can be reduced by magnesium, zinc, cadmium, iron, tin, copper and substances like hypophosphorous acid from acid solutions or from alkaline ones by formaldehyde.
Tin amalgam is used for "silvering" mirrors, gold and silver amalgam in gilding and silvering, cadmium and copper amalgam in dentistry, and an amalgam of zinc and tin for the rubbers of electrical machines; the zinc plates of electric batteries are amalgamated in order to reduce polarization.
Lead and zinc are mined in much smaller quantities, alum and sulphur are also.
It imports general merchandise and manufactures, and exports phosphates, iron, zinc, barley, sheep, wool, cork, esparto, &c. There are manufactories of native garments, tapestry and leather.
Troost made it available for specially high temperatures by employing porcelain vessels, sealing them with the oxyhydrogen blow-pipe, and maintaining a constant temperature by a vapour bath of mercury (3500), sulphur (4400), cadmium (860°) and zinc (1040°).
to), for the purpose of interposing at pleasure the prism it in the axis of the reading micrometer; this enables the observer to view the graduations on the face of the metallic thermometer TT (composed of a rod of brass and a rod of zinc).
Many of the elements such as copper, lead, zinc, nickel, cobalt and manganese have only been found in the substance of sea-weeds and corals.
It combines with many metallic sulphates (silver, zinc, cobalt, nickel, &c.) to form double sulphates of the type Cs2S04 RS04.6H20.
Mourlot has shown that aluminium sulphide, zinc sulphide and cadmium sulphide are the only sulphur compounds which can resist the heat of the electric furnace without decomposition or volatilization, and of these aluminium sulphide is the only one which is decomposed by water with the evolution of sulphuretted hydrogen.
Other minerals found in small quantities are copper, lead, zinc, iron ores, manganese ores and tin.
The first mines to be worked in Iowa were those for lead and zinc at Dubuque and to the northward.
These are little mined at present, only 110 tons of lead ore and 516 tons of zinc ore being taken from the mines in 1908.
m., embracing much of what is now the district of the Iowa lead and zinc mines.
With zinc dust in presence of caustic soda it yields the secondary alcohol oxanthranol, C 6 H 4: CO Choh: C 6 H 4, with tin and hydrochloric acid, the phenolic compound anthranol, C5H4: CO.
C (OH): C 6 H 4; and with hydriodic acid at i so C. or on distillation with zinc dust, the hydrocarbon anthracene, C 14 H 10.
It behaves more as a ketone than as a quinone, since with hydroxylamine it yields an oxime, and on reduction with zinc dust and caustic soda it yields a secondary alcohol, whilst it cannot be reduced by means of sulphurous acid.
Methyl chloride CH 3 C1, is a gas, boiling at - 23°, obtained by chlorinating methane, or better, from methyl alcohol; wood spirit is treated with salt and sulphuric acid, or hydrochloric acid gas conducted into the boiling spirit in the presence of zinc chloride, the evolved gas being washed with potash and dried by sulphuric acid.
It may be prepared from osmiridium by fusing the alloy with zinc, the zinc being afterwards removed by distillation.
As an alternative the osmiridium is fused with zinc, the regulus treated with hydrochloric acid, and then heated with barium nitrate and barium peroxide.
The tetroxide, 0s04, can be easily reduced to the metal by dissolving it in hydrochloric acid and adding zinc, mercury, or an alkaline formate to the liquid, or by passing its vapour, mixed with carbon dioxide and monoxide, through a red-hot porcelain tube.
The best metals for coinage are gold, silver, platinum, copper, tin, nickel, aluminium, zinc, iron, and their alloys; certain alloys of gold, silver, copper and nickel have the best combination of the required qualities.
Silver bullion, and the copper, tin and zinc required to make up bronze, are bought by the Mint and manufactured into coin, which is kept in stock and issued as it may be required.
Coinage bronze consists of copper 95 parts, tin 4 parts and zinc I part, and a ton yields X44 8 in pence or £ 373, 6s.
It is the centre of the mining district of Upper Silesia, and its population is mainly engaged in such operations and in iron and zinc smelting.
There are many other valuable ores - copper, iron, lead, zinc, antimony, chrome and manganese.
A small quantity of zinc (7 tons in 1906) is occasionally produced.
Copper, zinc and bismuth are also worked.
The manufacture of iron and steel goods is carried on; other industries include the manufacture of zinc wares, tanning, distilling and brewing.
Bernburg is the seat of considerable industry, manufacturing machinery and boilers, sugar, pottery and chemicals, and has lead and zinc smelting.
The Edison electric meter, like those of Sprague and Lane-Fox, was based upon the principle that when an electric current flows through an electrolyte, such as sulphate of copper or sulphate of zinc, the electrodes being plates of copper or zinc, metal is dissolved off one plate (the anode) and deposited on the other plate (the cathode).
It consisted of a glass vessel, containing a solution of sulphate of zinc, in which were placed two plates of pure amalgamated zinc. These plates were connected by means of a german-silver shunt, their size and the distance between them being so adjusted that about ii 0 - 0 - part of the current passing through the meter travelled through the electrolytic cell and -j o i j of the current passed through the shunt.
Before being placed in the cells the zinc plates were weighed.
The shunted voltameter was then inserted in series with the electric supply mains leading to the house or building taking electric energy, and the current which passed dissolved the zinc from one plate and deposited it upon the other, so that after a certain interval of time had elapsed the altered weight of the plates enabled the quantity of electricity to be determined from the known fact that an electric current of one ampere, flowing for one hour, removes 1.2533 grammes of zinc from a solution of sulphate of zinc. Hence the quantity in amperehours passing through the electrolytic cell being known and the fraction of the whole quantity taken by the cell being known, the quantity supplied to the house was determined.
Owing to the cost and trouble of weighing a large number of zinc plates, this type of meter fell into disuse.
The minerals of Siam include gold, silver, rubies, sapphires, tin, copper, iron, zinc and coal.
A freshly prepared surface of the metal closely resembles zinc in appearance, but on exposure to the air it rapidly tarnishes, becoming yellowish and ultimately grey or white in colour owing to the formation of a surface layer of calcium hydrate.
p. 55) by the interaction of nitrogen iodide with zinc ethyl, the products of the reaction being triethylamine and ammonia; the ammonia liberated was absorbed in hydrochloric acid, and 95% of the theoretical amount of the ammonium chloride was obtained.
At first a trade was carried on in wine, colonial wares, alcoholic liquors and salt; there are now manufactures of earthenware, glass and crystal, arms, paper, woollens, tools, lead, copper and zinc work, as well as breweries, and tobacco and cigar factories, and a trade in corn and butter.
Such was the case not only with some metals, such as lead, zinc, copper, but still more strikingly with textile materials such as wool, flax, and the like, and most of all with agricultural products such as grain, meat and meat products, timber.
Copper, silver, lead, and zinc are found in considerable quantities, and as regards quicksilver, Kwei-chow is probably the richest country in the world.
The olefines may be synthetically prepared by eliminating water from the alcohols of the general formula CnH2n+1 OH, using sulphuric acid or zinc chloride generally as the dehydrating agent, although phosphorus pentoxide, syrupy phosphoric acid and anhydrous oxalic acid may frequently be substituted.
Chablay, Comptes rendus, 1906, 1 43, p. 123) 2CH 2 :CH CH 2 OH+2NH 3 Na = CH,:CH CH3+CH2:CH CH20Na +NaOH+2NH31 from the lower members of the series by heating them with alkyl halides in the presence of lead oxide or lime: C5H,9-I-2CH31 =2H1+ C 7 H, 4 i and by the action of the zinc alkyls upon the halogen substituted olefines.
Sand, Ber., 1900, 33, pp. 1 34 0 et seq.), and those with a tertiary carbon atom yield double salts with zinc chloride.
The higher members of the series readily polymerize in the presence of dilute sulphuric acid, zinc chloride, &c. For the first member of the series see Ethylene.
It is a gas at ordinary temperature, and may be liquefied, the liquid boiling at -5° C. It combines with acetyl chloride in the presence of zinc chloride to form a ketone, which on warming breaks down into hydrochloric acid and mesityl oxide (I.
Paris) by heating zinc oxide with carbon, and was for some time considered to be identical with hydrogen.
It may be prepared by passing carbon dioxide over red-hot carbon, or red-hot iron; by heating carbonates (magnesite, chalk, &c.) with zinc dust or iron; or by heating many metallic oxides with carbon.
Algeria is rich in minerals, found chiefly in the department of Constantine, where iron, lead and zinc, copper, calamine, antimony and mercury mines are worked.
The most productive are those of iron and zinc. Lignite is found in the department of Algiers and petroleum in that of Oran.
The chief exports are sheep and oxen, most of which are raised in Morocco and Tunisia, and horses; animal products, such as wool and skins; wine, cereals (rye, barley, oats), vegetables, fruits (chiefly figs and grapes for the table) and seeds, esparto grass, oils and vegetable extracts (chiefly olive oil), iron ore, zinc, natural phosphates, timber, cork, crin vegetal and tobacco.
In the case of the Clark standard cell above mentioned the elements are mercury and zinc separated by a paste of mercurous sulphate mixed with a saturated solution of zinc sulphate.
In the Weston standard cell cadmium and cadmium sulphate are substituted for zinc and zinc sulphate; it has the advantage of a much smaller coefficient of temperature variation than the Clark cell.
Mag., 20, p. 126) consists of a U tube, one leg of which contains a rod of pure " amalgamated zinc, and the other a rod of freshly electrotyped copper.