US 6,682,005 B2 · Method of recovery of precious metals & heavy minerals

Abstract

Raw material containing precious metals and heavy minerals is introduced into a comminuting chamber. The raw material falls onto rotating chains which drive the material against the side wall of the chamber with sufficient velocity to cause the raw material to fracture. Air flows upwardly at the side wall and classifies the particles into a first fraction which falls to the floor of the chamber and a second fraction which is carried upward to a trommel. Large particles from the trommel are recycled to the chamber while fines are discarded as tailings. The rate of upward flow of air in the chamber, the rate of rotation of the chains and the size of particles separated by the trommel are all adjusted in order to ensure that the particles that collect on the floor of the chamber are rich in precious metals and heavy minerals.

Drawings

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Drawings

Claims22

Dependent claims

A process for recovering precious metals and/or heavy minerals from raw materials comprising the steps of:

(i) providing a comminuting chamber having an interior space defined, in part, by side and lower walls;
(ii) introducing said raw material into said chamber and causing said raw material to fracture into a first fraction of particles which contain a substantial proportion of precious metals and/or heavy minerals and which are of a size in the range at which any precious metals and/or heavy minerals therein are substantially liberated from the remainder of said raw material, a second fraction of particles which are of a size in the same range but which contain substantially less precious metals and/or heavy minerals and a third fraction of particles which are of a size larger than said range;
(iii) causing air to flow upwardly in said chamber;
(iv) adjusting the rate of upward flow of air of step (iii) in order to cause substantially all of the particles in the first fraction to fall onto said lower wall while particles in the second and third fractions are carried upward in the air flow;
and
(v) recovering particles which collect on said lower wall for separation of precious metals and/or heavy minerals therefrom.

3 more elements

A process for recovering precious metals and/or heavy minerals from raw materials comprising the steps of:

(i) providing a comminuting chamber having an interior space defined, in part, by side and lower walls;
(ii) directing raw material containing precious metals and/or heavy minerals downwardly onto impelling means located within said chamber such that said raw material collides with said impelling means and is driven thereby against said side wall with sufficient velocity to cause said raw material to fracture into a first fraction of particles which contain a substantial proportion of precious metals and/or heavy minerals and which are of a size in the range at which any precious metals and/or heavy minerals therein are substantially liberated from the remainder of said raw material, a second fraction of particles which are of a size in the same range but which contain substantially less precious metals and/or heavy minerals and a third fraction of particles which are of a size larger than said range;
(iii) causing air to flow into said chamber and along a path including:
upwardly along the side wall;
(iv) adjusting at least one of:
(a) the rate of upward flow of air of step (iii);
and (b) the velocity of the raw material of step (ii);
in order to cause substantially all of the particles in the first fraction to fall onto said lower wall while particles in the second and third fractions are carried upward in the air flow;
and
(v) recovering particles which collect on said lower wall for separation of precious metals and/or heavy minerals therefrom.

7 more elements

A process for recovering precious metals and/or heavy minerals from raw materials comprising the steps of:

(i) providing a comminuting chamber having an interior space defined, in part, by side and lower walls;
(ii) causing said raw material to strike said side wall with sufficient velocity to cause said raw material to fracture into a first fraction of particles which contain a substantial proportion of precious metals and/or heavy minerals and which are of a size in the range at which any precious metals and/or heavy minerals therein are substantially liberated from the remainder of said raw material, a second fraction of particles which are of a size in the same range but which contain substantially less precious metals and/or heavy minerals and a third fraction of particles which are of a size larger than said range;
(iii) causing air to flow into said chamber and along a path including:
upwardly along the side wall;
and to a separator
(iv) directing particles carried upward in the air flow into said separator for separating particles of a size within said range from particles of size larger than said range;
(v) recycling particles larger than said range from step (iv) to step (ii);
and
(vi) adjusting at least one of:
(a) the rate of upward flow of air of step (iii);
(b) the velocity of the raw material of step (ii);
and (c) the size of particles of step (iv) separated by said separator in order to cause substantially all of the particles in the first fraction to fall onto said lower wall while particles in the second and third fractions are carried upward in the air flow;
and
(vii) recovering particles which collect on said lower wall for separation of precious metals and/or heavy minerals therefrom.

11 more elements

A process for recovering gold from raw materials comprising the steps of:

(i) providing a comminuting chamber having an interior space defined, in part, by side and lower walls;
(ii) causing said raw material to strike said side wall with sufficient velocity to cause said raw material to fracture into a first fraction of particles which contain a substantial proportion of gold and which are of a size in the range at which any gold therein are substantially liberated from the remainder of said raw material, a second fraction of particles which are of a size in the same range but which contain substantially less gold and a third fraction of particles which are of a size larger than said range;
(iii) causing air to flow into said chamber and along a path including:
upwardly along the side wall;
and to a separator
(iv) directing particles carried upward in the air flow into said separator for separating particles of a size within said range from particles of size larger than said range;
(v) recycling particles larger than said range from step (iv) to step (ii);
and
(vi) adjusting at least one of:
(a) the rate of upward flow of air of step (iii);
(b) the velocity of the raw material of step (ii);
and (c) the size of particles of step (iv) separated by said separator in order to cause substantially all of the particles in the first fraction to fall onto said lower wall while particles in the second and third fractions are carried upward in the air flow;
and
(vii) recovering particles which collect on said lower wall for separation of gold therefrom.

11 more elements

Dependencies are inferred from the claim text.

Description4,973 words

Summary805 words

#This invention relates to a process for treatment of ores and scrap materials for the extraction of precious metals and heavy minerals and more particularly to a process which involves the simultaneous comminution of raw material and extraction of particles containing a high proportion of precious and heavy minerals from the raw material to facilitate the recovery of such metals and minerals.

#Comminution is an essential step in the extraction of metals from their ores and from scrap materials containing such metals. Gold, for example, occurs in quartz veins or lodes and in alluvial placer deposits. Gold is extracted from its ores by comminuting the ores into particles which can be treated by chemical processes such as amalgamation, chlorination and dissolution in cyanide for the extraction of gold.

#Comminution of ores or scrap materials can be carried out by conventional methods such as crushing, grinding and milling. A more recent method of comminution involves propelling particles of the material against a wall with sufficient force to cause the material to shatter into small particles. U.S. Pat. Nos. 5,839,671 and 6,024,307 issued on Nov. 24, 1998 and Feb. 15, 2000, respectively, both to Sand et al. describe the latter method.

Brief description of the drawings13 figures

#The process of our invention is preferably carried out in the apparatus illustrated in the drawings. In the drawings:

#FIG. 1 is a side view, partially broken away, of the apparatus;

#FIG. 2 is a sectional plan view taken along line 2—2 of FIG. 1;

Detailed description3,933 words

#Like reference characters refer to like parts throughout the description of the drawings.

#As seen in FIGS. 1 and 3, the apparatus, generally 7 has an input chute 8 for raw material and an output 9 for fine, light rejects or tailings. Main body 132 of the apparatus is the combination of pan 130 and lid assembly 131. Conventional forced air means or blower 99 is connected to main body 132 at inlet 100. The bottom of lid assembly 131 and pan 130 form the chamber in which liberation and separation of the precious metals and heavy minerals from the remainder of the raw material occurs.

#Downstream of the chamber 10 are output 9, cyclone 300 and cyclone collection output gate valve 301, and they, with input gate valve (not shown) connected to input 8, maintain intrinsic air pressure of the system. Blower 99 recycles air from cyclone 300. Main body 132 has a central axis about which central shaft 116 turns and about which separator 200 and chamber 10 are centered.

Facts

Application

10/125,538Filed 19 Apr 2002

Priority

CA 234451119 Apr 2001

Published

US 2002/0179751 A15 Dec 2002

Granted

27 Jan 2004

Term ended

19 Apr 2022

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification9 codes

B02C 13/16
With vertical rotor shaft, e.g. combined with sifting devices: with beaters hinged to the rotor
B02C 23/32
Passing gas through crushing or disintegrating zone: with return of oversize material to crushing or disintegrating zone
C22B 7/005
Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or…:…
C22B 11/00
Obtaining noble metals

Method of recovery of precious metals & heavy minerals

Life of this patent

Method of recovery of precious metals & heavy minerals

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims22

Description4,973 words

Drawings

Classification9 codes

Life of this patent

Description4,973 words