Method for removing arsenic mineral from a lead concentrate by reverse flotation with an ozone pre-treatment. The method comprises the steps of: receiving a slurry of the lead concentrate that has previously undergone flotation processes, bubbling ozone into the slurry of the lead concentrate to remove reagents used in previous flotation processes, adding a sulfide salt to the slurry to depress lead mineral, adding an alkali to increase the pH of the slurry, adding a collector and then a frother to the slurry for a reverse flotation processing and floating the arsenic mineral out of the lead mineral to obtain a now-purified lead concentrate.

The purpose of the present invention is to provide a flotation method with which a flotation treatment can be efficiently performed even when the substance to undergo flotation is fine mineral particles including particles having a particle diameter of about 25 m or less. This is a flotation method that separates and recovers mineral particles through a flotation treatment, wherein mineral particles are floated in a liquid to be processed by using minute air bubbles having an air bubble diameter of 200 m or less and air bubbles having a diameter larger than the minute air bubbles.

The present invention provides improved methods for purifying and/or removing multiply charged cations and suspended solids from water. In particular the process relates to an additive composition that has the appropriate surfactant characteristics for effectively removing multiply charged cations and suspended solids from an aqueous or oil/aqueous mixed phase via foam fractionation. According to the invention, a hydrophobically modified polymer that acts as an associative thickener is used in the presence of a source of alkalinity or anionic reactant as well as surfactant in appropriate ratios to facilitate multiply charged cation and suspended solids removal for water purification in any of a number of commercial, environmental and industrial applications.

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.

Methods for niobium concentration from a carbonatite host rock are presented. A basic process for niobium mineral concentration involves performing niobium mineral flotation, on a sufficiently liberated ore slurry, using at one least aromatic hydroxamate collector; and at least one lead salt as a performance modifier. A more optimized process further includes dispersion. A further optimized process includes: magnetic separation, dispersion, sulphide removal, fine suspended particle removal, and niobium cleaner flotation stages. The use of one of number of tested lead salts during flotation improves the yield, and lowers the cost as a significantly lower amount of the collector is required. The process is useful for recovering a variety of species of niobium minerals such as fersmite, pyrochlore, columbite, fergusonite, niobium-containing rutile, and niobium-containing ilmenite.

The present invention provides improved methods for purifying and/or removing oily particles, and/or contaminants suspended or dissolved in water. In particular the process relates to an additive composition that has the appropriate surfactant characteristics for effectively removing an oil phase from an oil/aqueous mixed phase via foam fractionation. According to the invention, a hydrophobically modified polymer that acts as an associative thickener is combined with surfactant in appropriate ratios to facilitate oil removal for water purification in any of a number of commercial, environmental and industrial applications.

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 stabilization process for an arsenic solution comprising thiosulfates, the process comprising: acidifying the arsenic solution to decompose the thiosulfates, to yield an acidified solution; oxidizing the acidified solution to oxidize residual As.sup.3+ to As.sup.5+ and reduced sulfur species to sulfates, to yield a slurry comprising elemental sulfur; separating elemental sulfur from the slurry to yield a liquid; oxidizing the liquid to oxidize residual reduced sulfur species, to yield an oxidized solution; and forming a stable arsenic compound from the oxidized solution.

The present invention provides improved methods for purifying and/or removing oily particles, and/or contaminants suspended or dissolved in water. In particular the process relates to an additive composition that has the appropriate surfactant characteristics for effectively removing an oil phase from an oil/aqueous mixed phase via foam fractionation. According to the invention, a hydrophobically modified polymer that acts as an associative thickener is combined with surfactant in appropriate ratios to facilitate oil removal for water purification in any of a number of commercial, environmental and industrial applications.

The present invention is directed to methods that can be used in the enrichment of metal sulfide ores in desired minerals in cases where the ores have sulfide-containing gangues. The method involves adding an oxidant to slurries prepared from the ores during, or immediately prior to froth flotation.