Cationic polymer selective depressants and use thereof in mineral ore purification methods

A metal purification process wherein one or more desired metals are recovered in more concentrated form from an impure metal containing composition comprising the desired metal and insoluble silicate and/or clay mineral contaminants, wherein said purification process includes a flotation step which includes the addition of an amount of at least one cationic polymer, wherein said flotation step is a direct flotation step, wherein said at least one cationic polymer has a molecular weight (MW) in the range of 200,000-2,000,000, wherein said added amount of cationic polymer functions as a depressant (cationic polymer depressant) that substantially prevents the flotation of insoluble silicates and/or clay minerals in the composition, and further wherein the recovered one or more desired metals are selected from copper, molybdenum, gold, zinc, lead, nickel, niobium, platinum, palladium, rhodium, ruthenium, iridium, and osmium;

• and said cationic polymer depressant comprises or consists of a cationic polyacrylamide copolymer comprising a polyacrylamide backbone produced by copolymerizing acrylamide with at least one cationic monomer, a cationic methacrylamide copolymer comprising a methacrylamide backbone produced by copolymerizing methacrylamide with at least one cationic monomer, polyamine, or polyDADMAC.