Len's face was pasty white and for a moment she thought he was going to throw up.
Slag or Cinder, a characteristic component of wrought iron, which usually contains from 0.20 to 2.00% of it, is essentially a silicate of iron (ferrous silicate), and is present in wrought iron simply because this product is made by welding together pasty granules of iron in a molten bath of such slag, without ever melting the resultant mass or otherwise giving the envelopes of slag thus imprisoned a chance to escape completely.
The heat evolved by this process of solidification retards the fall of temperature; but after this the rate of cooling remains regular until T (750°) on the line Sa (Ar 3) is reached, when a second retardation occurs, due to the heat liberated by the passage within the pasty mass of part of the iron and carbon from a state of mere solution to that of definite combination in the ratio Fe 3 C, forming microscopic particles of cementite, while the remainder of the iron and carbon continue dissolved in each other as austenite.
But immediately above this level the charge is relatively viscous, because here the temperature has fallen so far that it is now at the melting or formation point of the slag, which therefore is pasty, liable to weld the whole mass together es so much tar would, and thus to obstruct the descent of the charge, or in short to " scaffold."
It was not fused at a high point, but kept in a pasty state when working.
These materials were heated in pans in the furnace so as to combine in a pasty, half-fused condition.
The solution turns yellow in colour, and, when saturated, deposits a pasty mass of crystals.
Ust and ash, gave rise to torrents of pasty mud, that flowed p own the slopes and overwhelmed houses and villages.
With 10% of gold present the amalgam is fluid, and with 12.5% pasty, while with 13% it consists of yellowish-white crystals.
Sometimes it is almost pasty, and crumbles to powder when dried, so as to be susceptible of use as a pigment, forming the colour known as Cologne earth, which resembles umber or sepia.
Beyond this, wrought iron, and certain classes of steel which then were important, necessarily contained much slag or " cinder," because they were made by welding together pasty particles of metal in a bath of slag, without subsequent fusion.
Of these the first escapes immediately as a gas, and the others unite with iron oxide, lime, or other strong base present to form a molten silicate or silica-phosphate called " cinder " or " slag," which floats on the molten or pasty metal.
As the melting point of the metal is gradually raised by the progressive decarburization, it at length passes above the temperature of the furnace, about 1400° C., with the consequence that the metal, now below its melting point, solidifies in pasty grains, or " comes to nature."
- The few men who have, and are willing to exercise, the great strength and endurance which the puddler needs when he is stirring the pasty iron and balling it up, command such high wages, and with their little Soo-lb charges turn out their iron so slowly, that many ways of puddling by machinery have been tried.
This is at first colourless carbon dioxide, but later on inflammable gases come out of the mass, which at this stage has turned into a thicker, pasty condition, showing that the end of the reaction is near.
When the " candles " of carbon monoxide appear, the pasty mass is quickly drawn out of the furnace into iron " bogies," where it solidifies into a grey, porous mass, the " black-ash."
These fusible metals have the peculiarity of expanding as they cool; Rose's metal, for instance, remains pasty for a considerable range of temperature below its fusing point, contracts somewhat rapidly from 80° to 55°, expands from 55° to 35°, and contracts again from 35° to o°.
The seeds when placed in water for some time become coated with glutinous matter from the exudation of the mucilage in the external layer of the epidermis; and by boiling in sixteen parts of water they exude sufficient mucilage to form with the water a thick pasty decoction.
The amalgam is dipped out from the bowl into a canvas bag (the strainer), to separate the excess of the quicksilver from the pasty amalgam, which is then retorted and melted.
14 and 15 show Liegel's producer, the special object of which is to deal with any fuel (coal or coke) giving a tough, pasty slag on combustion.
The ultimate term of bacterial activity seems to be the production of ulmic acid, containing carbon 65.31 and hydrogen 3.85%, which is a powerful antiseptic. By the progressive elimination of oxygen and hydrogen, partly as water and partly as carbon dioxide and marsh gas, the ratios of carbon to oxygen and hydrogen in the rendered product increase in the following manner: The resulting product is a brown pasty or gelatinous substance which binds the more resisting parts of the plants into a compact mass.
This proves that the regular descent of the material in its pasty state can take place even in a space which is narrowing downwards.