BR-112020026120-B1 - A METHOD FOR SELECTIVELY RECOVERING A MINERAL FROM AN ORE, AND USING A PROMOTER

Abstract

The present invention is directed to a method for selectively recovering a mineral from an ore by applying a promoter that is a substituted ethylenediamine. Additionally, the present invention is directed to the use of said substituted polymeric alkylenediamine to separate a target mineral from an ore.

Inventors

• ADRIAN MAURICIO VILLANUEVA BERINDOAGUE
• Dale Barron
• Daniel CHIPFUNHU
• Alexej Michailovski
• SCOTT ALEXANDER DICKIE
• Marta Reinoso Garcia
• DERIS PRAWIRA

Assignees

• BASF SE

Dates

Publication Date

20260317

Application Date

20190703

Priority Date

20180704

Claims (11)

1. 1. Method for selectively recovering an iron-containing mineral from an ore, characterized in that it comprises the steps of i) crushing the ore, ii) preparing a pulp from the crushed ore obtained in step i), iii) adding at least one promoter comprising at least one substituted polymeric alkylenediamine, as an iron chelator, to the pulp obtained in step ii), wherein the at least one substituted polymeric alkylenediamine is a substituted polymeric ethylenediamine of formula (IIb) where m is in the range of 1 to 150, and the R5 substituents are independently of each other H, Li, Na, or K, and * is Z2N, where Z is independently of each other. Y is a carboxylate (-COOR5), sulfonate (-SO3R6), sulfate (-O-SO3R7), phosphonate (-P(=O)(OR8)(OR9)), phosphate (-O-P(=O)(OR10)(OR11)), carboxylic acid (-COOH), sulfonic acid (-SO3H), phosphonic acid (-P(=O)(OH)2), phosphoric acid (-OP(=O)(OH)2) moiety, or their deprotonated forms, R5, R6 and R7 are independently of each other H, alkyl, aryl, alkylaryl or arylalkyl, Li, Na or K, R8 and R10 are independently of each other alkyl, aryl, alkylaryl or arylalkyl, R9 and R11 are independently of each other H, alkyl, aryl, alkylaryl or arylalkyl, and iv) submit the pulp containing the hair minus one promoter obtained in step iii) foam flotation.
2. 2. Method according to claim 1, characterized in that the pH value of the pulp is adjusted to a range of 8.0 to 12.0.
3. 3. Method according to claim 1, characterized in that the concentration of at least one promoter in the pulp is in the range of 5 to 250 g/t.
4. 4. Method according to claim 1, characterized in that the pulp additionally comprises at least one collector.
5. 5. Method according to claim 4, characterized in that the collector is selected from the group consisting of xanthates, dithiophosphates, thiocarbamates, dithiocarbamates, xanthoformates, xanthate esters, dithiophosphates, monothiophosphates, dithiophosphinates, hydroxamic acids and their alkali metal or ammonium salts, alkyl-, alkenyl- and aryl sulfonic acids and salts thereof, mono- and diesters of phosphoric acid with long-chain alcohols or alkoxylated alcohols and salts thereof, mixtures of the aforementioned collectors with fatty acids and their salts, or mixtures thereof.
6. 6. Method according to claim 1, characterized in that the pulp additionally comprises at least one foaming agent.
7. 7. Method according to claim 1, characterized in that the iron-containing ore comprises gold, copper or a combination thereof.
8. 8. Method according to claim 1, characterized in that the R5 substituents are independently of each other H or Na and 90 to 100% by moles of the R5 substituents are Na.
9. 9. Method according to claim 1, characterized in that Z is independent of each other.
10. 10. Use of a promoter as defined in claim 1, characterized in that it is for separating a target mineral from an ore comprising iron.
11. 11. Use according to claim 10, characterized in that the target mineral contains gold or copper.

Description

[001] The present invention is directed to a method for selectively recovering a mineral from an ore by applying a promoter being a substituted ethylenediamine. Additionally, the present invention is directed to the use of said substituted polymeric alkylenediamine to separate a target mineral from an ore. [002] Ore beneficiation or improvement is normally achieved by the industrial application of the froth flotation process, in which valuable metal compounds contained in the ore are separated from the gangue and low-value compounds present in the starting material by means of selective hydrophobization. [003] Foam flotation is one of the most widely used separation processes for ore improvement. With the constant depletion of high-grade ores that are easily processable, the exploration of lower-grade, more complex and widespread reserves has become necessary. This has forced the mineral processing industry to adopt more sophisticated and innovative technologies to concentrate valuable minerals. In terms of flotation, the development of reagents that improve the selectivity of the foam flotation process is critical to its success in treating these low-grade, difficult-to-process ores. [004] Selectivity in froth flotation is controlled by the selective adsorption of reagents onto minerals at the mineral/water interface. For example, reagents that impart sufficient hydrophobic character to the minerals upon adsorption so that they become floatable are referred to as collectors. Finely crushed ore is typically treated with thiol reagents such as xanthates, dithiophosphates, or thionocarbamates that induce hydrophobization in the target mineral phases. [005] In the field of gold mining, it is desirable to separate copper and gold sulfides from iron sulfides and gangue minerals. This process requires that the pH value of the fluid paste be adjusted in such a way as to allow selective separation between particles of economic interest and the remaining part of the ore. In particular, it has been found that the separation process is more effective when the pH value of the fluid paste is in the alkaline range. [006] However, when the flotation process is carried out in a fluid slurry with an alkaline pH, the dissolution and precipitation of the iron contained in the crushed medium occurs. Most of this iron is precipitated as hydroxides that are produced on the surface of gold particles during the subsequent flotation process. Gold particles coated with iron hydroxides become non-floatable and therefore cannot be separated from the waste stream. Additionally, iron hydroxides retard the adsorption of xanthate collectors on the sulfide surfaces. Consequently, the presence of iron hydroxides caused by the alkaline pH of the fluid slurry leads to a significant loss of gold particles in the flotation process. [007] The application of chelating agents in froth flotation processes is well known in the art. In WO 2018/026796 A1, a method for separating silicon gangue from an iron ore is described, wherein a chelating agent being a coordination ligand such as ethylenediaminetetraacetic acid (EDTA) or a polymer comprising sulfonic acid or carboxylic acid monomers is applied. US 2007/0012630 A1 describes the application of amine-aldehyde resins as depressants for selective separation of solids and ionic species such as metal cations from aqueous media wherein chelating agents such as hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetraacetic acid (EDTA) or diethyltriaminepentaacetic acid (DTPA) can be added in order to intensify the separation process. [008] However, there is a need in the art for a method for the selective separation of valuable metals, especially gold, from ores that requires a flotation process at an alkaline pH. [009] Thus, it is an object of the present invention to provide a method for the selective separation of valuable metals, especially gold, from ores in which said valuable metal compounds are recovered in high quantities at an alkaline pH. [0010] The foregoing and other objectives are resolved by the subject matter of the present invention. [0011] According to a first aspect of the present invention, a method for selectively recovering a mineral from an ore comprises the steps of i) crushing the ore, ii) preparing a pulp from the crushed ore in step i), iii) adding at least one promoter comprising at least one substituted polymeric alkylenediamine to the pulp obtained in step ii), iv) subjecting the pulp containing the at least one promoter obtained in step iii) to froth flotation is provided. [0012] It has been surprisingly verified by the inventors that substituted polymeric alkylenediamines represent iron chelators with high chelating power and selectivity for iron (III) compounds at an alkaline pH. Thus, said substituted ethylenediamines are usable to selectively remove iron deposits from gold particles, making them prone to flotation agai