The invention provides methods and compositions for improving a froth flotation type separation. The method uses a microemulsion to improve the effectiveness of a frother. The improvement allows for low dosages of frother to work as well as much greater amounts of non-microemulsified frother.

A depressor in iron ore flotation comprises sugar cane bagasse and caustic soda so as to assist in the iron ore flotation. Sugar cane bagasse is used as a depressor in iron ore flotation, and a process of preparing depressor comprising sugar cane bagasse is disclosed.

A depressor in iron ore flotation comprises sugar cane bagasse and caustic soda so as to assist in the iron ore flotation. Sugar cane bagasse is used as a depressor in iron ore flotation, and a process of preparing depressor comprising sugar cane bagasse is disclosed.

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.

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.

A method of depressing copper sulfides and iron sulfides in a molybdenite floatation recovery process uses alkaline or alkaline earth polysulfides at high concentrate pH. The method of enriching molybdenite content from a slurry having molybdenite and at least one of iron sulfides and copper sulfides can include the steps of adding an effective amount of a depressing reagent selected from one or more alkaline poly sulfides, alkaline earth polysulfides, or a mixture thereof, to the slurry, wherein the pH of the slurry is greater than about 8.0; and passing a gas through the slurry to separate material by selective flotation, recovering the molybdonite from a froth.

A method of depressing copper sulfides and iron sulfides in a molybdenite floatation recovery process uses alkaline or alkaline earth polysulfides at high concentrate pH. The method of enriching molybdenite content from a slurry having molybdenite and at least one of iron sulfides and copper sulfides can include the steps of adding an effective amount of a depressing reagent selected from one or more alkaline poly sulfides, alkaline earth polysulfides, or a mixture thereof, to the slurry, wherein the pH of the slurry is greater than about 8.0; and passing a gas through the slurry to separate material by selective flotation, recovering the molybdonite from a froth.

Disclosed herein are methods and systems for recovery of ancylite, a rare earth mineral comprising strontium carbonate, from rare earth ore. In many embodiments, the disclosed methods and systems provide for recovery of greater than 50% of the ancylite from an ancylite containing ore. In many embodiments, the ore is subjected to flotation in the presence of an acid, for example a hydroxamic acid, such as octanohydroxamic acid. The ore may also be subjected to magnetic separation, for example wet high intensity magnetic separation.

The disclosure is directed to a sulfidizing agent obtainable by mixing M.sub.yS.sub.x and ZSH in a weight ratio of from about 90:10 to about 10:90, wherein M is chosen from Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, NH.sub.4.sup.+, Mg.sup.2+ and Ca.sup.2+, y is about 1 or about 2, x is from about 1.1 to about 5, and Z is independently chosen from Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+ and NH.sub.4.sup.+, and a process for using the sulfidizing agent in the recovery of one or more metal ores and/or polymetallic minerals from gangue.

The disclosure is directed to a sulfidizing agent obtainable by mixing M.sub.yS.sub.x and ZSH in a weight ratio of from about 90:10 to about 10:90, wherein M is chosen from Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, NH.sub.4.sup.+, Mg.sup.2+ and Ca.sup.2+, y is about 1 or about 2, x is from about 1.1 to about 5, and Z is independently chosen from Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+ and NH.sub.4.sup.+, and a process for using the sulfidizing agent in the recovery of one or more metal ores and/or polymetallic minerals from gangue.