US 4,288,304 A · Hydrometallurgical process for treatment of sulphur ores

Abstract

The invention provides a process for extracting zinc from a sulphur- and zinc-containing ore which involves (a) leaching the sulphur ore or concentrate with an aqueous solution of cupric chloride, which can be regenerated by means of a regenerating agent and air; (b) subjecting the solution thus obtained to liquid-liquid extraction by means of an organic phase, preferably containing a solvent, comprising an acid organophosphorus compound; and (c) recovering the zinc contained in the said organic phase after the said extraction, preferably by elution. If justified by the composition of the ore, the following optional recovery steps may then be performed: (1) if lead is present, recovery of lead by cementation (i.e., precipitation) or by crystallization of lead dichloride followed by cementation of the crystallizate; (2) if copper is present, recovery of copper by cementation or by liquid-liquid extraction; and (3) if precious metals, e.g., silver, are present, recovery of the precious metals by cementation or by selective electrolysis.

Claims69

Dependent claims

A hydrometallurgical process for treating a sulphur- and zinc-containing ore or concentrate to recover zinc therefrom, which process comprises the following three steps:

(a) leaching the ore or concentrate with an aqueous solution of cupric chloride thereby forming cuprous chloride;
(b) subjecting the solution thus obtained to liquid-liquid extraction by means of an organic phase to oxtract zinc into the organic phase while concurrently oxidizing cuprous chloride to cupric chloride;
and
(c) recovering the zinc extracted into the organic phase.

1 more element

A hydrometallurgical process for treating an initial product selected from the group consisting of a sulphurized ore and concentrate containing, as constituents, iron, zinc, silver, copper, and lead, the lead content being low in comparison to the copper content, in the form of their metal sulphides, to recover any or all of said constituents, comprising:

(a) leaching the initial product with an aqueous solution of cupric chloride whereby the metal sulphides are converted to their corresponding soluble metal chlorides, the cupric chloride is reduced to cuprous chloride, and elemental sulphur is produced;
(b) separating the sulphur and any unreacted residue from the reaction mixture;
(c) regenerating the resulting solution in situ, at atmospheric pressure, with air and a regenerating agent selected from the group consisting of hydrochloric acid and ferrous chloride, whereupon the cuprous chloride is oxidized to cupric chloride and recycled for additional leaching to step (a), and the iron is precipitated as goethite and separated from the aqueous solution;
(d) contacting a portion of the resulting aqueous solution, now free of sulphur, residue, and iron, and containing the aforesaid soluble metal chlorides and cuprous chloride, with metallic copper whereby silver is precipitated by cementation and recovered;
(e) contacting the aqueous solution obtained from step (d) and now free of sulphur, residue, iron, and silver, with metallic lead or zinc whereby metallic copper is precipitated by cementation and recovered;
(f) contacting the aqueous solution obtained from step (e) and now free of sulphur, residue, iron, silver, and copper, with metallic zinc whereby lead is precipitated by cementation and recovered;
(g) combining the aqueous solution obtained from step (f) and now free of sulphur, residue, iron, silver, copper, and lead, with the remaining portion of the aqueous solution from step (d) and subjecting the thus-combined aqueous solutions to liquid-liquid extraction with an organic phase containing an extraction agent for zinc, at a pH between 0.3 and 1.5, while concurrently oxidizing the cuprous chloride to cupric chloride, thereby to obtain a zinc-free aqueous phase, containing some dissolved metal chlorides, which is recycled to step (a) and an organic phase containing the extracted zinc;
and
(h) recovering the zinc from the organic phase of step (g) and recycling the organic phase back to step (g).

6 more elements

A hydrometallurgical process for treating an initial product selected from the group consisting of a sulphurized ore and concentrate containing, as constituents, iron, zinc, silver, copper, and lead, the lead content being high in comparison to the copper content, in the form of their metal sulphides, to recover any or all of said constituents, comprising:

(a) leaching the initial product with an aqueous solution of cupric chloride whereby the metal sulphides are converted to their corresponding soluble metal chlorides, the cupric chloride is reduced to cuprous chloride, and elemental sulphur is reduced;
(b) separating the sulphur and any unreacted residue from the reaction mixture;
(c) regenerating the resulting solution in situ, at atmospheric pressure, with air and a regenerating agent selected from the group consisting of hydrochloric acid and ferrous chloride, whereupon the cuprous chloride is oxidized to cupric chloride and recycled for additional leaching to step (a), and the iron is precipitated as goethite and separated from the aqueous solution;
(d) cooling the resulting aqueous solution, now free of sulphur, residue, and iron, and containing the aforesaid soluble metal chlorides including lead dichloride and cuprous chloride to crystallize the lead dichloride, separating the lead dichloride crystals, and recovering the lead therefrom;
(e) contacting a portion of the resulting aqueous solution now free of sulphur, residue, iron, and lead, and containing the aforesaid soluble metal chlorides and cuprous chloride, with metallic copper whereby silver is precipitated by cementation and recovered;
(f) contacting the aqueous solution obtained from step (e) and now free of sulphur, residue, iron, lead, and silver, with metallic lead or zinc whereby metallic copper is precipitated by cementation and recovered;
(g) combining the aqueous solution obtained from step (f) and now free of sulphur, residue, iron, lead, silver, and copper, with the remaining portion of the aqueous solution from step (e) and subjecting the thus-combined aqueous solutions to liquid-liquid extraction with an organic phase containing an extraction agent for zinc, at a pH between 0.3 and 1.5, while concurrently oxidizing the cuprous chloride to cupric chloride, thereby to obtain a zinc-free aqueous phase, containing some dissolved metal chlorides, which is recycled to step (a) and an organic phase containing the extracted zinc;
and
(h) recovering the zinc from the organic phase of step (g) and recycling the organic phase back to step (g).

6 more elements

A hydrometallurgical process for treating an initial product selected from the group consisting of a sulphurized ore and concentrate containing, as constituents, iron, zinc, silver, copper, and lead, the copper, lead, and zinc contents being high in comparison to the other metals, in the form of their metal sulfides, to recover any or all of said constituents, comprising:

(a) leaching the initial product with an aqueous solution of cupric chloride whereby the metal sulphides are converted to their corresponding soluble metal chlorides, the cupric chloride is reduced to cuprous chloride, and elemental sulphur is produced;
(b) separating the sulphur and any unreacted residue from the reaction mixture;
(c) regenerating the resulting solution in situ, at atmospheric pressure, with air and a regenerating agent selected from the group consisting of hydrochloric acid and ferrous chloride, whereupon the cuprous chloride is oxidized to cupric chloride and recycled for additional leaching to step (a), and the iron is precipitated as goethite and separated from the aqueous solution;
(d) cooling the resulting aqueous solution, now free of sulphur, residue, and iron, and containing the aforesaid soluble metal chlorides including lead chloride and cuprous chloride to crystallize the lead dichloride, separating the lead chloride crystals, and recovering the lead therefrom;
(e) subjecting a portion of the resulting aqueous solution, now free of sulphur, residue, and lead, and containing the aforesaid soluble metal chlorides and cuprous chloride to liquid-liquid extraction with an organic phase containing an extraction agent for zinc, at a pH between 0.3 and 1.5, while concurrently oxidizing the cuprous chloride to cupric chloride, whereupon an organic phase containing the extracted zinc and an aqueous phase containing the remaining soluble metal chlorides are obtained;
(f) recovering the zinc from the organic phase of step (e) and recycling the organic phase back to step (e);
(g) contacting the aqueous phase from step (e), now free of sulphur, residue, iron, lead, and zinc, and containing the remaining soluble metal chlorides, with copper whereby silver is precipitated by cementation and recovered;
(h) subjecting the resulting aqueous solution, now free of sulphur, residue, iron, lead, zinc, and silver, and containing cuprous chloride, to liquid-liquid extraction with an organic phase containing an extraction agent for copper to obtain a copper-laden organic phase, while concurrently oxidizing the cuprous chloride to cuprous chloride which is recycled to step (a) for additional leaching;
and
(i) recovering the copper from the organic phase and recycling the copper-free organic phase back to step (h).

7 more elements

A hydrometallurgical process for treating a sulphurized ore or concentrate containing iron and rich in zinc and copper, in the form of their sulphides to recover the sulphur, iron, zinc, and copper values therefrom, comprising:

(a) leaching the ore or concentrate with an aqueous solution of cupric chloride whereupon the zinc and copper sulphides are converted to soluble zinc and cupric chlorides, the cupric chloride is reduced to cuprous chloride, and elemental sulphur is produced;
(b) separating the sulphur and any unreacted residue from the reaction mixture;
(c) regenerating the resulting solution, in situ, at atmospheric pressure, with air and a regenerating agent selected from the group consisting of hydrochloric acid and ferrous chloride to oxidize the cuprous chloride to cupric chloride so as to provide a concentration of cuprous ions exceeding 1 gram per liter in the resulting aqueous solution of cupric chloride which is recycled for additional leaching to step (a) and the iron is precipitated as goethite and separated from the aqueous solution;
(d) subjecting the resulting aqueous solution, now free of sulphur, residue, and iron, and containing zinc and copper chlorides to liquid-liquid extraction with a neutral organic zinc extracting agent to obtain an organic phase containing the extracted zinc and an aqueous phase containing copper chlorides;
(e) recovering the zinc from the organic phase and recycling the zinc-free organic phase to step (d);
(f) subjecting the aqueous phase containing copper chlorides to liquid-liquid extraction with an organic copper-extraction cationic agent to obtain an organic phase containing the copper, the acidity released by this extraction being absorbed by the regeneration of cupric chloride;
and
(g) recovering the copper from the organic phase and recycling the copper-free organic phase to step (f).

5 more elements

A hydrometallurgical process for treating a sulphurized ore or concentrate containing iron, lead, and zinc sulphides to recover the lead and zinc values therefrom, comprising:

(a) contacting the ore or concentrate with an aqueous solution of cupric chloride approximately equal to the stoichiometrical quantity necessary to dissolve only the lead contained in the ore or concentrate thereby to obtain an aqueous solution of lead chloride and a solid residue of ore or concentrate;
(b) separating the aqueous solution of the lead chloride from the residue of the ore or concentrate;
(c) recovering the lead from the separated aqueous solution of lead chloride;
(d) leaching the residue of the ore or concentrate with an aqueous solution of cupric chloride whereupon the zinc sulphide is converted to zinc chloride, the cupric chloride is reduced to cuprous chloride, and elemental sulphur is produced;
(e) separating the sulphur and any unreacted residue from the reaction mixture;
(f) regenerating the resulting solution, in situ, at atmospheric pressure, with air and a regenerating agent selected from the group consisting of hydrochloric acid and ferrous chloride, whereupon the cuprous chloride is oxidized to cupric chloride and recycled for additional leaching to step (d) and the iron is precipitated as goethite and separated from the aqueous solution;
(g) subjecting the resulting aqueous solution, now free of lead, sulphur, residue, and iron, and containing zinc and copper chlorides to liquid-liquid extraction with a cationic zinc-extracing agent to obtain an organic phase containing the extracted zinc, and an aqueous phase containing copper chlorides which is recycled to step (d), the acidity released by extraction being absorbed by the regeneration of cupric chloride;
and
(h) recovering the zinc from the organic phase and recycling the zinc-free organic phase to step (g).

6 more elements

Dependencies are inferred from the claim text.

Hydrometallurgical process for treatment of sulphur ores

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Hydrometallurgical process for treatment of sulphur ores

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Abstract

Claims69