Soviet Union, metal-containing

Sulfides such as pentlandite, (Ni,Fe)9Ss, associated with copper, cobalt and precious metals so that the ores typically contain about lt% Ni. These are found in more temperate regions such as Canada, the former Soviet Union and South Africa. 

Ninety-eight per cent of the world s supply of platinum metals comes from three countries — the former Soviet Union (49%), the Republic of South Africa (43%), and Canada (6%). Because of the different proportions of Pt and Pd in their deposits, the Republic of South Africa is the major source of Pt and the former USSR of Pd. Only in the RSA (where the Bushveld complex contains over 70% of the world s reserves of the platinum metals at concentrations of 8-9 grams per tonne) are the... 

For the noble metals used in oxidation, the loading is about 0.1 oz per car, with calls for a million ounces per year. The current world production rates of platinum, palladium, and rhodium are 1.9, 1.6, and 0.076 million ounces respectively the current U,S. demand for platinum, palladium, rhodium, and ruthenium are 0.52, 0.72, 0.045, and 0.017 million ounces respectively (72, 73). The supply problem would double if NO reduction requires an equal amount of noble metal. Pollution conscious Japan has adopted a set of automobile emission rules that are the same as the U.S., and Western Europe may follow this creates a demand for new car catalysts approaching the U.S. total. The bulk of world production and potential new mines are in the Soviet Union and South Africa. The importation of these metals, assuming the current price of platinum at 155/oz and palladium at 78/oz, would pose a balance of payment problem. The recovery of platinum contained in spent catalysts delivered to the door of precious metal refiners should be above 95% the value of platinum in spent catalysts is greater than the value of lead in old batteries, and should provide a sufficient incentive for scavengers. 

Impure tantalum was isolated in 1825 by Swiss chemist Jean-Charles-Galissard de Marignac and, in purer form, by Heinrich Rose in 1844. It is found, in combination with its congener niobium, in tantalite/columbite (Fe, Mn)(Ta, Nb)206 ore, with tantalite containing more tantalum than niobium. Its crustal abundance is 1.7 parts per million, with major deposits in Australia, Brazil, China, Africa, the former Soviet Union, and Canada. The ore is concentrated, refined to the oxide Ta205, converted to K2TaF7, and reduced to the metal. 

The platinum-group metals (Ru, Os, Rh, Ir, Pd and Pt) are rare (Figure 23.1) and expensive, and occur together either native or in sulfide ores of Cu and Ni. Three sites of mineral deposits in the former Soviet Union, Canada and South Africa hold the world s reserves. The main source of ruthenium is from wastes from Ni refining, e.g. from pentlandite, (Fe,Ni)S. Osmium and iridium occur in osmiridium, a native alloy with variable composition 15-40% osmium and 80-50% iridium. Rhodium occurs in native platinum and in pyrrhotite ores (Fei S, n = 0-0.2, often with <5% Ni). Native platinum is of variable composition but may contain as much as 86% Pt, other... 

Catalytic Chain Transfer. A highly useful variant of chain transfer was discovered in the 1970-1980s in the Soviet Union (216). A number of reviews have been published in recent years (217-221) on this synthetic method which has acquired the nomenclature of either catalytic chain transfer (CCT) or special chain transfer (SCT). The most commonly adopted catalysts are based on low spin cobalt macrocycles, although other metal-containing complexes have also been suggested in the patent and scientific literature. Some typical catalyst structures are shown as 12 and 13. 

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