Patent ID: 7476371
Filing Date: 2009-01-13
Classification: C02F,C22B,C23F,Y02P

Abstract:
1. A process for producing a copper-containing aqueous solution comprising between about 90 and about 130 grams of dissolved copper per liter of solution, said process comprising: a) providing a leach liquor comprising water, monoethanolamine, and a monoethanolammonium salt, in a reactor wherein said monoethanolammonium salt is produced by admixing at least one acid with an aqueous monoethanolamine composition in an amount sufficient to provide between about 0.05 and about 0.7 equivalents of acid per mole of monoethanolamine, wherein the acid is selected from the group consisting of carbonic acid, phosphoric acid, sulfuric acid, boric acid, nitric acid, hydrofluoric acid, hydrochloric acid, fluoboric acid, oxalic acid, malonic acid, gallic acid, citric acid, ascorbic acid, formic acid, acetic acid, propionic acid, and mixtures thereof, except that if the acid is carbonic acid there is at least one other acid additionally present; b) providing a copper mass having a three dimensional open network that is permeable to the leach liquor, wherein the copper mass is present in an amount greater than about 200 grams per liter of leach liquor; c) providing to the reactor a gas comprising air, oxygen, or mixture thereof; and d) contacting the leach liquor with the air, oxygen, or mixture thereof and with the copper mass, thereby causing dissolution of a portion of the copper mass and forming the copper-containing aqueous solution product comprising between about 90 and about 130 grams of dissolved copper per liter of product, wherein the temperature of the leach liquor is maintained at a temperature between about 18° C. and 100° C. and wherein the average copper dissolution rate is greater than about 2.1 grams of copper per liter of leach liquor per hour.