# US 10,369,577 B2 · Compositions and methods for selective separation of minerals from sulfide ores

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- Number: US 10,369,577 B2
- Document ID: US10369577B2
- Status: Granted
- Kind: B2
- Application number: 15/726,810
- Filed: 2017-10-06
- Published: 2018-04-12
- Granted: 2019-08-06
- Earliest claimed: 2016-10-07
- Assignees: Cytec Industries Inc.
- Applicants: Cytec Industries Inc.
- Inventors: Mikael Brasse; Esau Arinaitwe; Devarayasamudram Ramachandran Nagaraj
- Web page: https://patentgrep.com/patent/US10369577B2

## CPC

- B03D 1/02: Froth-flotation processes
- B03D 1/01: containing nitrogen
- B03D 1/012: containing sulfur
- B03D 1/016: Macromolecular compounds
- C07C 333/14: Dithiocarbamic acids; Derivatives thereof
- C08L 33/26: Homopolymers or copolymers of acrylamide or methacrylamide
- B03D 1/008: containing oxygen
- B03D 2201/005: Dispersants
- B03D 2201/007: Modifying reagents for adjusting pH or conductivity
- B03D 2201/02: Collectors
- B03D 2201/04: Frothers
- B03D 2201/06: Depressants
- B03D 2203/02: Ores
- B03D: FLOTATION; DIFFERENTIAL SEDIMENTATION (sedimentation in general B01D21/00; in combination with other separation of solids B03B; sink-float separation B03B5/28; detergents, soaps C11D)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Compositions including blends of one or more acrylamide/allyl thiourea polymer as a first depressant, and one or more carboxyalkyl dithiocarbamate compound as a second depressant, and their use as depressants in the beneficiation of sulfide minerals from ores and/or concentrates are disclosed herein, along with methods for selectively separating value sulfide minerals from non-value sulfide minerals in a froth flotation process for the recovery of such value minerals.

## Claims

### Claim 1

A composition of matter comprising a blend of a first depressant and a second depressant,
wherein the first depressant is a polymer having a weight average molecular weight from 1,000 g/mol to 1,000,000 g/mol comprising:
i) X units of an acrylamide derivative according to Formula (I):
wherein
each of R, R1, and R2 is independently chosen from H, C1-C4 alkyl, or C6-C12 aryl; and
X is a residual mole percent fraction by weight based on the total mole percent by weight of Y and Z;
ii) Y units of a thiourea derivative according to Formula (II):
wherein
R3 is chosen from H, a C1-C4 alkyl, or C6-C12 aryl;
each of R4 and R5 is independently chosen from H, C1-C4 hydrocarbyl, or a C6-C12 aryl; and
Y is a mole percent fraction from 1% to 50% by weight based on the total weight of X, Y, and Z; and
iii) Z units of a polymerization residue of any monomer copolymerizable with the derivatives according to Formulas (I) and (II), wherein Z is a mole percent fraction from 0% to 50% by weight based on the total weight of X, Y, and Z; and
wherein the second depressant is a dithiocarbamate compound according to Formula (III):
wherein
R6 is chosen from H, or a moiety having from 1-12 carbon atoms and one or more functional groups selected from OH, SO3−M+, COO−M+, and CONR8R9, wherein each of R8 and R9 is independently chosen from H or C1-C4 alkyl;
R7 is chosen from a moiety having from 1-12 carbon atoms and one or more functional groups selected from OH, SO3−M+, COO−M+, and CONR8R9, wherein each of R8 and R9 is independently chosen from H or C1-C4 alkyl;
each instance of M is independently chosen from a cation selected from the group consisting of alkali metal, metal, or R104N+, wherein each instance of R10 is independently chosen from H or a C1-C12 alkyl,
wherein the blend is further characterized as being an aqueous solution; and having 4<pH≤14 at a temperature from −5° C. to 85° C.

### Claim 2 (depends on 1)

A composition according to claim 1, wherein the first depressant and the second depressant are present at a weight ratio in a range from 20:80 to 80:20.

### Claim 3 (depends on 2)

A composition according to claim 2, wherein the weight ratio of the first depressant to the second depressant is from 25:75 to 50:50.

### Claim 4 (depends on 1)

A composition according to claim 1, wherein said blend of the first and second depressant is from 10 to 50 parts by weight, per 100 parts by weight of water, and having 4<pH≤14 at a temperature from 20° C. to 50° C.

### Claim 5 (depends on 1)

A composition according to claim 1, wherein each of R, R1, R2, R3, R4, and R5 is H.

### Claim 6 (depends on 1)

A composition according to claim 1, wherein said first depressant has a weight average molecular weight from 10,000 g/mol to 100,000 g/mol.

### Claim 7 (depends on 1)

A composition according to claim 1, wherein X units of Formula (I) to Y units of Formula (II) is present at a weight ratio in a range from 10:90 to 95:5.

### Claim 8 (depends on 7)

A composition according to claim 7, wherein X units of Formula (I) is greater than 50% and no Z units are present.

### Claim 9 (depends on 1)

A composition according to claim 1, wherein R6 is H, R7 is CH2COO−M+, and each M+ in Formula (III) is K.

### Claim 10 (depends on 1)

A composition according to claim 1, wherein the blend of the first and second depressant further comprises, or is used in combination with, a value mineral enhancing amount of a surface modifying agent.

### Claim 11 (depends on 10)

A composition according to claim 10, wherein the surface modifying agent is one or more compound selected from the group consisting of NaSH, NaCN, Nokes reagent, mercapto ethanol, thioglycolic acid or salts thereof (including sodium, potassium, calcium, magnesium, or aluminum salts), sodium ferrocyanides, potassium ferrocyanides, hydroxyethyl trithiocarbonates, carboxyethyl trithiocarbonates, sodium trithiocarbonates, hydrogen peroxide, ozone, air, oxygen, sulfur dioxide, zinc cyanide, calcium cyanide, arsenic Nokes, mercapto propionic acid, mercapto succinic acid, 2-thiouracil, and thioglycerol.

### Claim 12 (depends on 10)

A composition according to claim 10, wherein the surface modifying agent is NaSH, Na2S, sodium salt of thioglycolic acid, or Nokes reagent and is present from 0.5 wt. % to 99.5 wt. %, based on the total weight of the blend.

### Claim 13

A method for selectively separating value sulfide minerals from non-value sulfide minerals in a froth flotation process for the recovery of said value minerals from an ore or concentrate containing said value and non-value minerals, the method comprising:
adding to one or more stage of the froth flotation process a first depressant and a second depressant in an amount sufficient to increase the value minerals in the froth, thereby selectively separating the value minerals from the non-value minerals,
wherein the first depressant is a polymer having a weight average molecular weight from 1,000 g/mol to 1,000,000 g/mol comprising:
i) X units of an acrylamide derivative according to Formula (I):
wherein
each of R, R1, and R2 is independently chosen from H, C1-C4 alkyl, or C6-C12 aryl; and
X is a residual mole percent fraction by weight based on the total mole percent by weight of Y and Z;
ii) Y units of a thiourea derivative according to Formula (II):
wherein
R3 is chosen from H, a C1-C4 alkyl, or C6-C12 aryl;
each of R4 and R5 is independently chosen from H, C1-C4 hydrocarbyl, or a C6-C12 aryl; and
Y is a mole percent fraction from 1% to 50% by weight based on the total weight of X, Y, and Z; and
iii) Z units of a polymerization residue of any monomer copolymerizable with the derivatives according to Formulas (I) and (II), wherein Z is a mole percent fraction from 0% to 50% by weight based on the total weight of X, Y, and Z; and
wherein the second depressant is a dithiocarbamate compound according to Formula (III):
wherein
R6 is chosen from H, or a moiety having from 1-12 carbon atoms and one or more functional groups selected from OH, SO3−M+, COO−M+, and CONR8R9, wherein each of R8 and R9 is independently chosen from H or C1-C4 alkyl;
R7 is chosen from a moiety having from 1-12 carbon atoms and one or more functional groups selected from OH, SO3−M+, COO−M+, and CONR8R9, wherein each of R8 and R9 is independently chosen from H or C1-C4 alkyl;
each instance of M is independently chosen from a cation selected from the group consisting of alkali metal, metal, or R104N+, wherein each instance of R10 is independently chosen from H or a C1-C12 alkyl.

### Claim 14 (depends on 13)

A method according to claim 13, wherein the first and second depressant are added as a one pack blend.

### Claim 15 (depends on 4, 13)

A method according to claim 13, wherein the first and second depressant are as defined by claim 4.

### Claim 16 (depends on 13)

A method according to claim 13 further comprising adding an effective amount of one or more flotation reagents selected from the group consisting of collectors, frothers, froth phase modifiers, dispersants, depressants, suppressants, pH regulators, and activators to one or more stages of said froth flotation process.

### Claim 17 (depends on 13)

A method according to claim 13 further comprising recovering said value minerals from the froth.

### Claim 18 (depends on 13)

A method according to claim 13, wherein the first and second depressant are added together in a one pack blend in a dosage of 2 kg/ton to 15 kg/ton of ore or concentrate; or wherein the first and second depressant are co-dosed and the dosage of the first depressant is from 0.5 kg/ton to 1.5 kg/ton of ore or concentrate, and the dosage of the second depressant is from 1.5 kg/ton to 25 kg/ton of ore or concentrate.

### Claim 19 (depends on 13)

A method according to claim 13, wherein said value minerals are selected from the group consisting of sulfides of molybdenum, copper, zinc, nickel, lead, and mixtures thereof.

### Claim 20 (depends on 19)

A method according to claim 19, wherein said value mineral is molybdenite and said non-value mineral is copper sulfides and/or iron sulfides.