Particulate of sulfur-containing ore materials and heap made therefrom

• US 6,696,283 B1
• Filed: 11/09/2001
• Issued: 02/24/2004
• Est. Priority Date: 07/10/1991
• Status: Expired due to Fees

• Current Assignee: Newmont USA Limited (Newmont Corp.)
• Original Assignee: Newmont USA Limited (Newmont Corp.)
• Inventors: Hill, David L., Brierley, James A.
• Primary Examiner(s): BOS, STEVEN J
• Application Number:
  US09/991,484
• Time in Patent Office: 837 Days
• Field of Search: 423/DIG.17, 423/27, 423/29, 252/1, 435/262, 435/243, 435/252.1
• US Class Current: 435/262
• CPC Class Codes: C22B 3/18 with the aid of microorganisms or enzymes, e.g. bacteria or algae
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y10S 423/17 Microbiological reactions

Abstract

Disclosed is a particulate of an ore material having a metal value metal value and a matrix material having a sulfur content wherein the sulfur is present in an oxidation-reduction state of zero or less, the particulate comprising (a) a core particle of the ore material, with the core particle having a size of less than about two inches; and (b) a layer of particles of the ore material and an inoculate of sulfur biooxidizing bacteria in admixture with the particles; wherein the particulate has sufficient strength to retain at least about 95% of a void volume for a column height of about 6 feet for at least 200 days when continuously bathed in a solution comprised of the inoculate or a nutrient therefor. Also disclosed is a heap comprising a plurality of the particulate.

Claims

1. A particulate of an ore material having a metal value and a matrix material having a sulfur content wherein the sulfur is present in an oxidation-reduction state of zero or less comprising

a. a core particle of said ore material, said core particle having a size of less than about two inches;

and

b. a layer of particles of said ore material and an inoculate of sulfur biooxidizing bacteria in admixture with said particles

wherein said particulate has sufficient strength to retain at least about 95% of a void volume for a column height of about 6 feet for at least 200 days when continuously bathed in a solution comprised of said inoculate or a nutrient therefor.

2. A particulate as defined in claim 1 wherein said layer of particles have at least 100 sq. cm of surface area for a volume of about 100 cubic centimeters.

3. A particulate as defined in claim 1 wherein said core particle has a mean average diameter of about ½

to about ¾

inches; and

wherein said inoculate comprises an inoculate solution, comprising about 8 to 12% of the total weight of said particulate.

4. A particulate as defined in claim 1 wherein the particles of the ore comprise crushed ore passing a screen of ½

inch mesh size.

5. A particulate as defined in claim 4 wherein said crushed ore has admixed thereto at least 1% to 5% by weight of a slime, on a dry basis, for forming a layer on said core particle.

6. A particulate as defined in claim 1 wherein the particulate comprises at least about 10⁵ to 10⁹ bacteria per milliliter of inoculate for said particulate.

7. A particulate as defined in claim 6 wherein the bacteria is a mixture of Thiobacillus ferroxidans and Thiobacillus thiooxidans.

8. A particulate as defined in claim 1, wherein the particulate has a size of 1½

inch or smaller.

9. A particulate as defined in claim 1, wherein the particulate has a size of 1 inch or smaller.

10. A particulate as defined in claim 1, wherein the particulate has a size of from ¼

inch to ½

inch.

11. A heap comprising a plurality of the particulate of any one of claims 1-7 and 8-10.

12. A heap comprising a plurality of particulates of an ore material having a metal value and a matrix material having a sulfur content wherein the sulfur is present in an oxidation-reduction state of zero or less, each said particulate comprising

a. a core particle of said ore material, the core particle having a size of less than about two inches and

b. a layer of particles of said ore material and an inoculate of sulfur-biooxidizing bacteria in admixture with said particles

wherein each of said particulate has sufficient strength to retain at least about 95% of a void volume for a column height of about 6 feet for at least 200 days when continuously bathed in a solution comprised of said inoculate or a nutrient therefor.

13. A heap as defined in claim 12, wherein a core of said heap is constructed of particulates with a bacterial inoculant of Sulfobacillus thermosulfidooxidans, or Sulfolobus acidocaldarius, Sulfolobus BC, Sulfolobus solfataricus or Acidanus brierleyi.