Lead, Copper, Zinc Containing Minerals

Montana. These deposits consist of stibnite and other sulfide minerals containing base metals and silver or gold. Ores of the complex deposits are mined primarily for lead, copper, zinc, or precious metals antimony is a by-product of the treatment of these ores. 

TETRAHEDRITE. A mineral of tire composition, (Cu. Fe)12A (S]3, isomorphous with tennantite. The color ranges from steel-gray to iron-black, The mineral frequently contains cobalt, lead, mercury, nickel, silver, or zinc in replacement of the copper. Tetrahedrite usually occurs in tetrahedral crystals associated with copper ores. The mineral is considered an important copper ore and sometimes is a valuable ore for silver. The mineral sometimes is referred to asfahiore, gray copper ore, and stylotypite. 

Zirconium is the eleventh most abundant element in the earth s crust, which contains 0.028 percent of this element. It is more abundant than copper, lead, nickel, or zinc. Zirconium minerals always contain from 0.5 to 2 percent of chemically similar hafnium, which seldom occurs naturally by itself. 

Ore mining presents matty of the same dangers of harmful chemical modification ofthe environment as does fossil fuel recovery. Sulfur-containing minerals frequently ac-compaity ores and, unless properly recovered and treated, promote the formation of acid waters and contamination of the atmosphere with sulfur dioxide (SO2) and hydrogen sulfide (H2S). Acidic sludges and slurries are produced in conjunction with the recovery and processing of iron, copper, zinc, and lead cyanide salts are used in the recov-... 

Electrochemical processes, primarily in the refining of copper, lead, and zinc, yield certain rare metals as by-products. The value of these by-product metals should be included within the electrochemical industry. In Table 7, the major metals derived as byproducts of electrorefining operations are listed. The total value of shipments for each of these metals was based on data contained in the Bureau of Mines Minerals Yearbook Since copper refining... 

Differential flotation can be achieved when only specific minerals are floated. This is done by the use of additives to the pulp to depress or promote the collection of particular mineral surfaces. The particular response of minerals contained in an ore will differ widely, and hence there is a considerable variation in flotation practices from one plant to another. The general approach, however, is to first float copper and depress the other base metal sulfides, then float lead and finally zinc. The aim is generally to depress pyrite, but this can be difficult and it is often the major diluent in lead and zinc concentrates. 

In Mexico, ores are available containing pyragyrite and proustite, mined entirely for silver extraction, and Mexico derives 50% of its silver production from mines containing these so-called primary silver minerals The other half is, as in the rest of the world, a by-product of copper, zinc and lead production. 

Arsenopyrite FeAsS is the most important arsenic mineral. As a rule the arsenic-containing ores are mined mainly for their contents of the more attractive metals, gold, silver, copper, lead and zinc. On treatment of the complex ores, arsenic oxide As O is obtained. Reduction with charcoal gives metallic arsenic. The most important commodity is however the oxide. The world production of As Oj was 35000 tonnes in 2001, with China as the largest producer country (16000 tonnes), followed by Chile (8000 tonnes), Mexico and Peru (2500 tonnes each), Kazakhstan and Russia (1500 tonnes each), Belgium and France (1000 tonnes each). 

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