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.

A system for separating competing anions from per- and polyfluoroalkyl substances (PFAS) in a flow of water contaminated with PFAS and elevated levels of competing anions that includes a separation subsystem which receives the flow of water contaminated with PFAS and elevated levels of competing anions and separates competing anions from the PFAS and concentrates the PFAS to produce a treated flow of water having separated competing anions therein and a flow of water having a majority of PFAS therein. At least one anion exchange vessel having an anion exchange resin therein receives the flow of water having a majority of PFAS therein and removes PFAS from the water to produce a flow of treated water having a majority of the PFAS removed. The separation of competing anions by the separation subsystem increases the treatment capacity of the anion exchange resin to remove PFAS from the contaminated water.

A method for improving the rheological properties of mineral slurry comprising adding a copolymeric dispersing agent to the slurry to disperse silicate minerals. Also disclosed is a method for flotating mineral slurry.

A process is provided for separation of at least one metal sulfide from a mixed sulfide concentrate. The process includes: subjecting the mixed sulfide concentrate to flotation in which at least one sulfide including antimony, arsenic and a first metal is floated and at least one sulfide including a second metal is depressed. The flotation yields a first metal concentrate having the at least one sulfide including antimony, arsenic and the first metal and a second metal concentrate having the at least one sulfide including the second metal. The first metal concentrate is leached to yield a further concentrate and a leach solution. The further concentrate includes the first metal and the leach solution includes soluble antimony and soluble arsenic. The process further includes oxidizing the leach solution to yield an antimony precipitate and an arsenic solution, and forming a stable arsenic compound from the arsenic solution.

Methods for purifying one or more value materials are provided. The method can include contacting an aqueous mixture comprising a value material and a contaminant with a dispersant and a depressant to produce a treated mixture. A weight ratio of the dispersant to the depressant can be from about 1:1 to about 30:1. The method can also include recovering a purified product comprising the value material from the treated mixture. The purified product can have a reduced concentration of the contaminant relative to the aqueous slurry.