Multiple-stage grinding circuit

Patent metadata

Field	Value
Publication number	US-11420211-B2
Application number	US-201716762882-A
Country	US
Kind code	B2
Filing date	Dec 29, 2017
Priority date	Dec 29, 2017
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A method includes separating, in a first stage of separating, crushed ore material by size into a first fines stream and a first coarse stream; grinding the first coarse stream in a second stage of grinding; feeding the product of the second stage of grinding back to the step of separating; feeding the first fines stream from the step of separating to a recovery circuit; producing a rejected stream from the recovery circuit of crushed ore material that does not meet the target mineral size; separating, in a second stage of separating, the rejected stream from the recovery circuit into a second fines stream and a second coarse stream; grinding the second coarse stream in a third stage of grinding; and feeding the product of the third stage of grinding back to the recovery circuit.

First claim

What is claimed is:

1. A method for multiple-stage grinding, the method comprising:
providing a feed of crushed ore material;
grinding the crushed ore material in a first stage of grinding in a first grinder;
separating, in a first stage of separating, the crushed ore material by size into a first fines stream and a first coarse stream;
grinding the first coarse stream in a second stage of grinding in a second grinder that is different from the first grinder;
feeding the product of the second stage of grinding back to the step of separating;
feeding the first fines stream from the step of separating to a recovery circuit;
recovering, by the recovery circuit, a target mineral size of the crushed ore material to produce a marketable product;
producing a rejected stream from the recovery circuit of crushed ore material that does not meet the target mineral size;
separating, in a second stage of separating, the rejected stream from the recovery circuit into a second fines stream and a second coarse stream;
grinding the second coarse stream in a third stage of grinding; and
feeding the product of the third stage of grinding back to the recovery circuit.

2. The method of claim 1 , further comprising diluting the rejected stream from the recovery circuit with water.

3. The method of claim 2 , further comprising removing water from the crushed ore material from the recovery circuit using one or more dewatering cyclones.

4. The method of claim 3 , wherein the second stage of separating is completed by the one or more dewatering cyclones.

5. The method of claim 1 , further comprising recovering the same material from the second stage of grinding, via the recovery circuit, and the third stage of grinding, via the recovery circuit, to produce the marketable product.

6. The method of claim 1 , wherein the target mineral size for the second stage of grinding is larger than the target mineral size for the third stage of grinding.

7. The method of claim 6 , wherein grinding the coarse stream in a second stage of grinding comprises grinding to a target mineral size of approximately 80% passing 300 microns.

8. The method of claim 6 , wherein grinding the coarse stream in a third stage of grinding comprises grinding to a target mineral size of approximately 80% passing 100 microns.

9. The method of claim 1 , wherein the second stage of grinding is completed using a ball mill.

10. The method of claim 1 , wherein the third stage of grinding is completed using a stirred mill.

11. A multiple-stage grinding process comprising:
a first-stage grinding mill configured to receive crushed ore material, and complete a first stage of grinding the crushed ore material;
a first separator configured to separate the crushed ore material into a first fines stream and a first coarse stream;
a second-stage grinding mill that is different from the first-stage grinding mill, wherein the second-stage grinding mill is configured to receive the first coarse stream, and complete a second stage of grinding the crushed ore material;
a recovery circuit configured to receive the first fines stream, configured to recover a target mineral size of the crushed ore material, producing a marketable product, and to produce a rejected stream of material that does not meet the target mineral size;
a second separator configured to receive the rejected stream from the recovery circuit and separate the crushed ore material into a second fines stream and a second coarse stream; and
a third-stage grinding mill configured to receive the second coarse stream, and complete a third stage of grinding the crushed ore material, wherein the product of the third-stage grinding mill is fed back to the recovery circuit.

12. The multiple-stage grinding process of claim 11 , wherein the second separator comprises a different geometry to the first separator.

13. The multiple-stage grinding process of claim 11 , wherein the target mineral size for the second-stage grinding mill is larger than the target mineral size for the third-stage grinding mill.

14. The multiple-stage grinding process of claim 11 , wherein the second-stage grinding mill comprises a ball mill.

15. The multiple-stage grinding process of claim 11 , wherein the third-stage grinding mill comprises a stirred mill.

Assignees

• Fluor Tech Corp

Inventors

• Sherman Mark

Classifications

• B02C23/14

  with more than one separator · CPC title

• B03B7/00

  Combinations of wet processes or apparatus with other processes or apparatus, e.g. for dressing ores or garbage · CPC title

• B02C21/00 Primary

  Disintegrating plant with or without drying of the material (for grain B02C9/04) · CPC title

• B02C23/38 Primary

  in apparatus having multiple crushing or disintegrating zones · CPC title

• B02C23/12

  with return of oversize material to crushing or disintegrating zone · CPC title