Production of copper, nickel oxide and zinc oxide

Claim 2

The process of claim 1 in which a portion of the aqueous leach liquor is mixed with the reconstituted ammonia-ammonium carbonate solution, and in which this ammoniacal metal ammonium carbonate solution is used as the leach solution.

Claim 3

The process of claim 1 in which the leaching operation is carried out at a temperature oF at least 100* F. and under a partial pressure of oxygen of at least 2 p.s.i.

Claim 4

The process of claim 1 in which the leach liquor is contacted with a gas at a temperature of at least 1,000* F.

Claim 5

The process of claim 1 in which a portion of the gaseous product of the decomposition reaction is reheated to at least 1, 000* F. and is recycled to the decomposition step to serve as the hot gas.

Claim 6

A process for producing high-purity copper oxide from elemental copper-bearing materials which comprises: leaching the copper-bearing material with an ammonium carbonate containing ammoniacal aqueous leach solution at a temperature of at least about 100* F. under a partial pressure of oxygen of at least about 2 p.s.i. to obtain a substantially iron-free copper-containing aqueous leach liquor, separating the copper-containing aqueous leach liquor from the insoluble residue of the leaching step, contacting the thus separated copper-containing aqueous leach liquor with hot gases at a temperature of between about 400* to 1,900* F. to decompose the copper ammonia carbonate to form ammonia, carbon dioxide and steam and to form solid copper oxide and copper carbonates, separating the copper carbonate and copper oxide from the gases, contacting the thus separated copper carbonates and oxides with hot gases in a second reaction zone at a temperature of between about 400* to 1,900* F. to thermally decompose the copper carbonate to obtain the corresponding copper oxide, the reduction and oxidation properties of said hot gases being controlled to produce a substantially pure copper oxide product of a predetermined oxygen content, separating the solid metal oxide product from the gaseous products of the decomposition reaction, condensing and absorbing the gaseous products and recycling the resulting ammonia-ammonium carbonate solution to the leaching step of the process, and recovering the high-purity copper oxide product.

Claim 7

The process of claim 7 in which the high-purity copper oxide product is contacted with high-purity sulfuric acid to produce high-purity copper sulfate.

Claim 8

The process of claim 7 in which the high-purity copper oxide is contacted with a reducing gas to produce a high-purity copper powder.

Claim 9

The process of claim 7 in which the gases used to thermally decompose the copper leach solution are a portion of the recycle gases resulting from the decomposition of the aqueous copper ammonium carbonate.

Claim 10

The process of claim 7 in which the leaching of the copper-bearing material is carried out at a temperature of between about 80* and 250* F.

Claim 11

The process of claim 7 in which the leaching of the copper-bearing material is carried out at a partial pressure of oxygen of from about 2 to 10 p.s.i.

Claim 12

The process of claim 7 in which part of the aqueous leach liquor of reduced copper content from the liquid decomposition is condensed and recycled to the leaching step of the process.

Claim 13

The process of claim 7 in which the decomposition of the copper-containing aqueous leach liquid is carried out using air at about 400* F.

Claim 14

The process of claim 7 in which the decomposition of the copper-containing aqueous leach liquid is carried out using the combustion products from a direct gas fired heater at about 400* F.

Claim 15

The process of claim 15 in which the decomposition of the copper containing aqueous leach liquid is carried out at a combustion products inlet temperature of between 400* and 1,900* F.