Enzyme oxidation of sulfides in minerals
AssigneeNorthwest Ecological Research & Development, Inc.
InventorFrederick J. Richardson
Life of this patent
Estimating the term…
Abstract
A process for treating sulfide ores to reduce the sulfur content or recover the metal content therefrom comprises the use of enzymatic action to solubilize the sulfur and metal content. A nutrient, such as a saccharide, is used along with yeast spores which feed on the sugar and produce enzymes which act on sulfur in the sulfide ore to cause the sulfur to go into solution and to dissolve those metals which are soluble in strongly acidic solution. Sulfuric acid can be formed from the sulfide ores or from free sulfur by reaction with water, with evolution of hydrogen sulfide gas. Oxidation of at least a portion of the hydrogen sulfide can be achieved to regenerate sulfuric acid.
Claims14
A process for treating a solid mineral ore containing one or more contaminants in the form of free or combined sulfur as metal sulfides, comprising the following steps:
- (a) reducing or pulverizing the mineral ore to granular or smaller particle size;
- (b) forming a mixture of pulverized ore and water at room temperature;
- (c) adding microorganisms in the form of baker's yeast or malt and a saccharide to the mixture of ore and water;
- (d) allowing the mixture of step (c) to stand for a period sufficient for enzymatic action to carry a significant amount of free or combined sulfur into aqueous solution as sulfuric acid or a metal sulfate;
- and
- (e) removing at least a portion of said sulphuric acid or metal sulphate from said aqueous solution.
Dependencies are inferred from the claim text.