Copper-ores Sentence Examples

Silver, gold, lead and copper ores occur in many localities.

Then copper mining rapidly developed and considerable gold was obtained from copper ores.

Until the development of copper mining, silver was produced only in small quantities along with gold, but as much more silver than gold was obtained from the copper ores the value of the silver product increased from $2,630,000 in 1881 to $24,615,822 in 1892.

The product then fell off, but in 1907, when it amounted to 9,317,605 fine ounces, valued at $6,149,619, more than nine-tenths of it was derived from the copper ores in Silverbow county.

Excellent beds of coal are found in different places, especially about Kulja, but the fairly rich copper ores and silver ores have ceased to be worked.

Toledo is the port of entry for the Miami customs district and is an important shipping point for the iron and copper ores and lumber from the Lake Superior and Michigan regions, for petroleum, coal, fruit, and grain and clover-seed.

With the nickel copper is always found, and copper ores are worked on their own account in a few localities, such as Bruce mines.

Since all sulphuretted copper ores (and these are of the most economic importance) are invariably contaminated with arsenic and antimony, it is necessary to eliminate these impurities, as far as possible, at a very early stage.

To-day more than eight-tenths of the copper ores of the world are reduced to impure copper bars or to fine copper at the mines; and where the character of the ore permits, the cupola furnace is found more economical in both fuel and labour than the reverberatory.

High grade copper ores have been produced in the Seven Devils and Washington districts of Washington county; there are deposits, little developed up to 1906, in Lemhi county (which was almost inaccessible by railway) and in Bannock county; the copper mined in 1905 was valued at $1,134,846, and in 1907, according to state reports, at $2,241,177, of which about two-thirds was the output of the Cceur d'Alene district in Shoshone county.

Among the exports are coffee, cacao, dyewoods, hides, skins, and copper ores.

The fire assay for copper ores was abandoned years ago and the electrolytic method took its place; this in turn is now largely replaced by volumetric methods.

It is associated with beds of lava and volcanic ash, some of which contain copper ores.

Silver, gold, lead and copper ores occur in many localities..

In many instances it has been replaced by mechanical furnaces, which are now common in roasting sulphide copper ores (see Sulphuric AcID).

Cupric sulphate is obtained commercially by the I 91,000 96,000 1 35, 000 218,400 291,000 900,000 oxidation of sulphuretted copper ores (see above, Metallurgy; wet methods), or by dissolving cupric oxide in sulphuric acid.