US 4,162,915 AGranted

Process for treating lead-copper-sulphur charges

AssigneeMetallurgie Hoboken-Overpelt

InventorsRobert H. Maes, Luc M. Fontainas

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Abstract

Lead-copper-sulphur charges (e.g., ores and concentrates) containing at least one of the elements Fe, Ag, Bi, Zn and Sn are treated pyrometallurgically to recover their metal values by a process comprising the steps of (a) smelting the charge to produce a slag phase containing at least about 10% Pb, a copper matte phase containing less than about 65% Cu, and a lead bullion phase; (b) separating the slag, matte and bullion phases formed in step (a); (c) reducing the molten slag separated in step (b) to decrease the lead content thereof to less than about 2% and form thereby a lead bullion phase; and (d) separating the slag and bullion phases formed in step (c). According to the process of the invention, the copper matte phase formed in step (a) is substantially free of iron; most of the silver is collected in step (a) in the copper matte and lead bullion phases; most of the bismuth is collected in the bullion phase of step (a); most of the iron, zinc, and tin are collected in the slag phase formed in step (a); the lead bullion phase formed in step (c) is substantially free of silver and bismuth; the slag phase formed in step (c) is substantially free of zinc and tin, and most of the zinc is contained in fly ashes.

Claims13

Dependent claims

A process for pyrometallurgically treating a Pb-Cu-S charge containing at least one of the elements Fe, Ag, Bi, Zn and Sn, to recover the metal values of said charge, comprising the steps of:

(a) smelting the charge while maintaining chemically reducing, neutral or oxidizing conditions under which said smelting produces
(i) a slag phase containing at least about 10% Pb;
(ii) a copper matte phase containing less than about 65% Cu, the amount of said copper content decreasing with decreasing Cu:S ratio in the Pb-Cu-S charge;
and
(iii) a lead bullion phase, the strength of the reducing conditions employed in said smelting step being greater with increasing degree of oxidation of the Pb-Cu-S charge and greater with decreasing content of Pb in the slag phase produced in said smelting step and the strength of the oxidizing conditions employed in said smelting step being lower with increasing degree of oxidation of the Pb-Cu-S charge and lower with decreasing content of Pb in the slag phase produced in said smelting step;
(b) separating from each other the slag, copper matte and lead bullion phases produced in step (a);
(c) reducing the slag phase separated in step (b), in the molten state, with a strong reducing agent whereby the lead content of the slag phase is lowered to a value less than about 2% thereby producing a lead bullion phase;
and
(d) separating from each other the slag and lead bullion phases produced in step (c),
thereby obtaining in step (a) a matte phase which is substantially free of Fe, collecting in step (a) most of the Ag in the matte and bullion phases, most of the Bi in the bullion phase and most of the Fe, Zn and Sn in the slag phase, and obtaining in step (c) a lead bullion which is almost free from Ag and Bi, a slag which is almost free from Zn and Sn and fly ashes containing most of the Zn.

7 more elements

Dependencies are inferred from the claim text.