Custom smelting

Recent process development work for the recovery of copper, nickel, cobalt and precious metals (Au, Pt, Pd) from PolyMet s NorthMet deposit is described. The process uses a number of flotation process steps combined with hydrometallurgical treatment to produce a range of possible products including copper and nickel flotation concentrates for custom smelting, mixed nickel and cobalt hydroxide for refining and a precious metal precipitate for treatment. 

Leclair, R, Hancock, P and Hickey, T, 1998. Lead smelting operations at Noranda s BeUedune plant From vertical integration to custom smelting, in Zinc and Lead Processing, pp 109-124 (Canadian Institute of Mining and Metallurgy (CIM) Montreal). 

In Europe, a small number of large custom smelters (Metaleurop, MetaUgesellschaft and Nuova Samim) are responsible for the majority of lead concentrate purchases, sometimes holding equity interests in supplying mines. Similarly, three Japanese smelters account for almost the entire custom concentrate imports into Japan. Asarco (in the USA) has custom smelted... 

A critical part of the Kidd Creek mining, milling, and smelting operations is the partnering relationship between Kidd Creek and Durex plus Durex engineering, manufacturing, customer service, and outside material suppliers. All of these people are dedicated to... 

Of semi-black colour. But there are also Fluors of other colours, if we look closely into this matter. It is the custom, when metals are smelted, to treat them and cast them in. The material is restored in a more fluid state, even as with the kind of stone out of which pyrites is made. If the experiment were made, I consider that the best colours would be obtained from Fluors thus treated. 

I949> PP- 86-103 Snyder, Death-Dealing Smog, p. 35. Part of chemical industry Zinc is separated from ore as a vapor and condensed, while other smelting processes collect liquid metal. Much of it was sold as a powdered oxide chemical, with paint companies as major customers, rather than as a metal. A zinc plant upriver from Donora belonged to DuPont. 

The Cu 5 cleaner concentrate represents a high grade (-30% copper concentrate) while the Cu cleaner scavenger tails and the Cu rougher tails are nickel rich and may individually or in combination be processed at a custom nickel smelter facility. Alternately these nickel rich materials could be processed via PLATSOL . The pyrrhotite 3 cleaner concentrate is low grade and unlikely to be toll smelted. This material is ideally suited to PLATSOL process treatment. 

Outotec provides complete tailored process solutions for customers needs. Decades of experience in the supply of Flash Smelting plants have resulted in extensive metallurgical know-... 

The smelting of copper concentrates at Outokumpu Harjavalta plant is carried out in a flash smelting furnace. The copper smelting process is very sensitive to variations in the furnace feed. In custom smelters, like in Harjavalta, tens of different concentrates are treated. It has become clear that the variations in the feed mixture composition cause undesirable fluctuations in the matte percent, i.e. the copper content in tapped matte, which is closely related to the oxidation grade in the flash smelting furnace. Stochastic modelling has been applied successfully to similar blending processes (Westerlund et al. 1980). Thus, it was well motivated to analyse the dynamic behaviour of the feed mixture preparation process (Korpi 2000). 

There may also be important regional differences in treatment terms, and in relative concentrate prices. Variations in freight costs, for instance, will be an important influence on mine returns from concentrate sales. On the smelting side, treatment charges in Europe tend to be marginally lower than in other regions because of greater competition between plants for concentrate supplies. The Japanese custom smelters, in contrast, face very... 

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