Production, mined lead

Mexico, the world s leading producer of silver since the Spanish conquest, obtains virtually its entire silver production from lead—2inc 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, Ari2ona, 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. 

Bismuth is referred to as a minor metal. It is not generally mined for its own intrinsic value, rather it is mined primarily as a by-product of lead or copper ores. In China, however, bismuth can be found ia tungsten ores. In BoHvia the metal has been mined for its own value, but this has not happened on a consistent basis over the years because fluctuations ia the bismuth price have at times made it uneconomical to recover. 

Trade association of manufacturers of lead products and lead components mining companies, smelters and refiners of lead. Provides lead information to consumer s and is a clearinghouse for lead recycling information. 

World production of mined lead was 3 331 000 tonnes in 1991 and a further 5 558 000 tonnes was refined by reprocessing. In the same year US eonsumption of Pb in metal produets was 1 125 000 tonnes (ineluding 967 000 tonnes in storage batteries). In addition, some 57 250 tonnes of other oxides and 29 750 tonnes of miseellaneous Pb-eontaining produets were eonsumed. The US market priee of Pb dropped from 1.05/kg in 1990 to 0.40/kg in 1993 due in part to the eollapse in use of PbEta in petrol. 

In 1996, mines in Missouri and Alaska accounted for 93% of total US. lead mine production. Domestic lead mine production decreased in 1992 and 1993 as a result of low lead, gold, and silver metal prices, but increased the following three years when several mines either expanded or reopened due to increased metal prices. Domestic lead mine production reached 436,000 metric tons in 1996 and an estimated 450,000 metric tons in 1997, which was still less than the 484,000 metric tons produced in 1990 (Larrabee 1997 Smith 1998). 

Aquatic life in proximity to mining activities, lead arsenate pesticides, metal finishing industries, lead alkyl production, and lead aerosol fallout... 

Chloropyromorphite is a common constituent of lead-bearing solid phase in lead-mining areas of the UK, and it was considered the end product of lead weathering (Cotter-Howells, 1994). The presence of lead phosphate in metal-contaminated soils was also confirmed by Ruby et al. (1994). Furthermore,... 

Primary and secondary sources of lead exist in the United States and throughout the world [29], U.S. mine production of lead in concentrate is approximately 450,000-500,000 metric tons per year, which represents approximately 15% of the world production. Other countries with significant mine production of lead include Australia, Canada, China, Mexico, and Peru. Refining of secondary lead is dominated by the U.S. production, although other major sources include Canada, China, France, Germany, Italy, Peru, Spain, and the United Kingdom. In the United States, approximately 79% of the current lead refinery production is derived from secondary sources. Worldwide, secondary sources... 

Gas and liquid emissions and mine tailing are the principal pollution sources sulfur dioxide release, particulate, diffused dust, cooling wastewater, ash production, fluorine, lead, cadmium and zinc emissions. 

R.W. Lee, Production of Lead in the Imperial Smelting Process , Lead into the Future. The Institution of Mining and Metallurgy, Buxton, United Kingdom, 1996,75-89. 

P. Arthur, A. Siegmimd and M. Schmidt, Operating Experience with QSL Submerged Bath Smelting for Production of Lead Bullion , Savard-Lee Symposium. Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, Canada, 1993. 

T. Kamegai, H. Fukuyama, T. Fujisawa and C. Yamauchi, "Modeling of Coluirm in New Jersey Reflux Refining Process for High Purity Zinc Production", Zinc Lead 95. T. Azakami, N. Masuko, J.E. Dutrizac and E. Ozberk, Eds., The Mining and Materials Processing Institute of Japan, Tokyo, Japan, 1995,90-99. 

Lead in nature occurs in a number of minerals such as galena (lead sulfide), ce-russite (lead carbonate) and anglesite (lead sulfate) none of these dissolve in water. The world production of lead is about 6 million t annually. If societies only used newly mined lead, deposits would be exhausted in a mere 15 years. This limited natural supply of lead and the toxicity of water-soluble lead salts is more than enough... 

Lead is obtained from mixed lead and zinc ores, where lead after concentration by a series of flotation processes is sintered to oxidize the ore to lead oxide. The oxides are reduced and the metallic lead refined. The worldwide yearly lead production has been constant during the last 10 years, around 3.5 million tons. The most important lead-mining countries are the United States, the former Soviet Union, and Australia as shown in Table 1. In addition to mining lead is produced from scrap. The total world lead production amounted to 5.8 million tons in 1988 [3]. 

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