This invention relates to a collector composition for the direct froth flotation of nonsulfide ores comprising a) 50-99 wt.-% of a mixture of fatty acids and b) 1-50 wt.-% of an N-acyl derivative of sarcosine of the formula (I)

##STR00001## wherein R is a saturated or unsaturated hydrocarbon chain with 7 to 21 carbon atoms, wherein the mixture of comprises 10.0-35.0 wt.-% of fatty acid having a saturated C.sub.11 hydrocarbon group, 2.5-15.0 wt.-% of fatty acid having a saturated C.sub.13 hydrocarbon group, 10.0-25.0 wt.-% fatty acid having a monounsaturated C.sub.17 hydrocarbon group and 20.0-45.0 wt.-% fatty acid having a bisunsaturated C.sub.17 hydrocarbon group.

Improved sparge compositions for reverse froth flotation separation and uses thereof, and methods of reverse froth flotation are described. The sparge compositions comprise sulfonated polymeric modifiers which can act as dispersants and depressants, and the compositions are suitably used in the reverse froth flotation of particulate material containing ultrafine particles. For example, the compositions and methods can be used in the separation of iron oxide beneficiary from iron ores comprising silica, silicates, and the like.

Improved sparge compositions for reverse froth flotation separation and uses thereof, and methods of reverse froth flotation are described. The sparge compositions comprise sulfonated polymeric modifiers which can act as dispersants and depressants, and the compositions are suitably used in the reverse froth flotation of particulate material containing ultrafine particles. For example, the compositions and methods can be used in the separation of phosphate beneficiary from ores comprising phosphates, dolomite, calcite, clay, silica, silicates, carbonates, and mixtures thereof.

The invention is related to a flotation process using an improved collector to remove alkaline earth metal carbonate impurities from phosphate ores. The flotation feed may be conditioned with the improved carbonate collector at acidic pH, and subjected to a reverse flotation. The cell overflow may be collected as waste in which carbonate minerals dominate, and the cell underflow may be the phosphate concentrate. The collector may be a combination of chemicals, comprising: (1) any kind of fatty acids, either conventional fatty acid, saponified fatty acid, or modified fatty acid; (2) chemicals with sulfonate or sulfate groups, such as dodecylbenzene sulfonic acid (DDBSA) or its salt, sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium coco sulfate (SCS), etc.; and (3) phosphorous-bearing chemicals, such as sodium tripolyphosphate (STPP), sodium hexametaphosphate (SFMP), trisodium phosphate (TSP), Tetrasodiumpyrophosphate (TSPP), etc. With the improved collector, the separation selectivity and phosphate recovery may be significantly improved.

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.

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.

Improved partitioning compositions for froth flotation of mineral ores, and improved methods of froth flotation using the partitioning compositions have been developed. The partitioning compositions are suitably added to a mineral ore slurry in a single addition to provide a sparge composition that is ready for sparging. The use of the partitioning compositions obviates the need to adjust the pH of the ore slurry before or after the addition, and further avoids the use of compounds having a flashpoint of 60 C. or less. Meanwhile, the partitioning compositions obtain improved grade and recovery of phosphate product (P.sub.2O.sub.5) in froth flotation of phosphate ores, when compared to conventional chemistry and methods used for froth flotation of a phosphate ores.