Lead-zinc mine

Marine mammals collected near heavily urbanized or industrialized areas or near zinc pollution point sources usually had elevated zinc concentrations when compared to individuals of the same species and of similar age from relatively pristine environments (Eisler 1984). Zinc concentrations in tissues of the ringed seal (Phoca hispida) were essentially the same in animals near a lead-zinc mine and in those of a distant reference site, although lead and selenium burdens were elevated in the vicinity... 

Grey field slug, Deroceras reticulatum, near lead-zinc mine Digestive gland 3968 DW 6... 

Table 10.15 Comparisons of flotation results of OPCF and traditional flotation in concentrator of Xitieshan lead-zinc mine...

The flotation separation of galena, sphalerite and pyrite in Fankou lead-zinc mine is very complicated because these three minerals are finely disseminated. The OPCF technology is also successfully applied to this plant to separate these three minerals. Here, pH is modified to 12 by lime and pulp potential is maintained as less than 170 mV. The mixture of xanthate and DDTC is used as a collector in flotation of galena. CUSO4 is used as a collector in the flotation of sphalerite. The principal flowsheet of OPCF for flotation separation of Fankou lead-zinc ore is given in Fig. 10.20. The comparison of results of plant production for OPCF and old flowsheet is listed in Table 10.16. It can be seen that the OPCF technique... 

Cadmium is found in low concentrations in most soils and waters. It is produced as a by-product of zinc and lead mining and smeltering. Industrial use of cadmium has led to a dramatic increase in environmental problems caused by this element. Cadmium is used in semiconductors, nickel-cadmium batteries, electroplating, polyvinyl chloride (PVC) manufacturing, and control rods for nuclear reactors. The most important sources for aquatic contamination are active and inactive lead-zinc mines, land application of sewage sludge, zinc-cadmium smelters, effluents from plastic and steel production, and wastewaters from the production of nickel-cadmium batteries and electroplating (Zuiderveen, 1994). 

Mexico, the world s leading producer of silver since the Spanish conquest, obtains virtually its entire silver production from lead—zinc mines in the central cordillera. Mexico retained its dominance in silver production until the discovery of the Comstock Lode in Nevada in 1859. Discoveries in Colorado, Arizona, and Montana placed the United States as the world s top silver producer from 1871 until 1900. As these mines played out, Mexico s vast resources returned it to its former position of dominance. 

In the Commonwealth of Independent States (CIS, formerly the USSR), nearly 50% of the CIS production comes from Kazakhstan. Silver is produced from the lead—zinc mines at Ostkamen, Shymkent, and Leninogorsk (ca 1000 t) and also in Russia s Far East, where it is a by-product of the tin deposits near Khabarovsk, and of the copper and gold deposits in the Ural Mountains. 

U.S. silver production from 1985 to 1994 averaged 1588 t/yr. Less than one quarter of this output comes from silver mine districts, however. About half is as by-product of gold mines about one quarter comes from copper and lead—zinc mines. The silver production in Mexico from 1985 to 1994 averaged 2256 t/yr, and Pern, at the southern extremity of the cordillera, where silver is a by-product of copper and lead—zinc mines, averaged 1810 t/yr. 

Asarco has devised a method of treating the water from a lead-zinc mine with sulfate-reducing bacteria that generate hydrogen sulfide in situ to precipitate the metal ions.55 Arsenic can be precipitated from the effluent of gold extraction as FeAs04 2I I20.56 Aluminum-loaded Shirasu zeolites can also remove arsenic from water.57 Car-... 

The area of investigation comprised a groundwater system, which was presumably contaminated by emissions of a waste deposit landfill as the result of a leak discovered in the bottom sealing. Additionally, it was found that waste water was seeping down into the drainage water of an old lead/zinc mine situated below the deposit. Since 1999 technical measures were performed in order to diminish the resulting emissions. 

In mineralized zones, particularly in regions of sulfidic lead-zinc mi neralizations, significant accumulations of cadmium takes place in the river sediments. The area around Coeur d Alfene River in Idaho, the Ten nessee River near Knoxville, and many rivers in Wales, Southeast England are examples of the lead-zinc mining effect. 

Neuberger, J.S. and Hollowell, J.G., Lung cancer excess in an abandoned lead-zinc mining and smelting area, Scl Total Environ., 25, 287, 1982. 

Johansen P, Hansen MM, Asmund G, et al. 1991. Marine organisms as indicators of heavy metal pollution Experience from 16 years of monitoring at a lead-zinc mine in Greenland. Chem Ecol 5(1-2) 35- 55. 

Ore dressing separates the different minerals present and produces concentrates for metal production. China and Austraha are the greatest producers of zinc concentrates in the world. Other large producers are Canada, Peru and the United States. In the USA the leading zinc mining state is Alaska. The Red-Dog Mine there was opened in 1989 and since then mine production in the United States has exceeded the smelter capacity for zinc in that country. 

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