Speiss

speiss [spīs]

(metallurgy)

A mixture of impure metal arsenides and antimonides resulting from the smelting of certain ores such as cobalt and lead.

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Speiss 

an intermediate product or by-product in nonferrous metallurgy, an alloy of arsenides and antimonides of iron, cobalt, nickel, copper, or other metals formed in the melting of raw materials with a high arsenic content. Cobalt speiss is formed in the melting of arseniccobalt raw materials. To extract the cobalt, this speiss is roasted to remove arsenic and sulfur, and the oxides produced are subjected to further metallurgical treatment or are sulfatized by sintering with concentrated sulfuric acid and converted by hydrometallurgical treatment.

In the production of lead, speiss is formed in the shaft melting of charges with a high arsenic content and in the melting of copper drosses. As a consequence of its low solubility and relatively high density (8–8.5 g/cm₃), speiss is found in a separate layer between the molton lead and the matte.

Speiss is a good collector of lead, silver, and gold; because significant amounts of these metals are lost when using the alloy, the formation of speiss in lead production is undesirable. Speiss is usually treated together with matte in converters with the partial distillation of arsenic and antimony and production of low-quality black copper.

REFERENCES

Loskutov, F. M. Metallurgiia svintsa. Moscow, 1965.
Osnovy metallurgii, part 4. Moscow, 1967.

M. P. SMIRNOV