Disclosed are a slow-release inhibitor for high-magnesium sulfide mineral flotation and an application thereof, where the inhibitor is a nano colloidal particle of an alkaline earth fluoride such as CaF.sub.2 and BaF.sub.2 or a highly-reactive natural alkaline earth metal mineral powder. When applied to the flotation separation of a high-magnesium sulfide ore, the inhibitor can slowly release F ions to preferentially form a MgF.sub.2 layer on the magnesium-containing mineral surface, which provides a structure similar to MgF.sub.2 on a surface of oxidized gangue minerals such as magnesium oxide, changing surface electrical property of the magnesium-containing mineral, inhibiting heterogeneous coagulation of magnesium-containing minerals and sulfide ores due to electrostatic attraction and reducing entrainment, enveloping and agglomeration of gangue minerals to efficiently inhibit the flotation of oxidized gangue minerals such as magnesium oxide.

Disclosed are a slow-release inhibitor for high-magnesium sulfide mineral flotation and an application thereof, where the inhibitor is a nano colloidal particle of an alkaline earth fluoride such as CaF.sub.2 and BaF.sub.2 or a highly-reactive natural alkaline earth metal mineral powder. When applied to the flotation separation of a high-magnesium sulfide ore, the inhibitor can slowly release F ions to preferentially form a MgF.sub.2 layer on the magnesium-containing mineral surface, which provides a structure similar to MgF.sub.2 on a surface of oxidized gangue minerals such as magnesium oxide, changing surface electrical property of the magnesium-containing mineral, inhibiting heterogeneous coagulation of magnesium-containing minerals and sulfide ores due to electrostatic attraction and reducing entrainment, enveloping and agglomeration of gangue minerals to efficiently inhibit the flotation of oxidized gangue minerals such as magnesium oxide.

Compositions for adjusting the pH of sea water to be useful in metal floatation processes are described, as are methods utilizing such compositions. Precipitation of insoluble magnesium salts interferes with pH adjustment of sea water when conventional sources of CaO and/or Ca(OH).sub.2 are used, however addition of nonreactive particulates (such as waste materials from industrial processes) permits use of such low quality sources of CaO/Ca(OH).sub.2 and reduces consumption of high quality CaO/Ca(OH).sub.2 for this purpose.

Compositions for adjusting the pH of sea water to be useful in metal floatation processes are described, as are methods utilizing such compositions. Precipitation of insoluble magnesium salts interferes with pH adjustment of sea water when conventional sources of CaO and/or Ca(OH).sub.2 are used, however addition of nonreactive particulates (such as waste materials from industrial processes) permits use of such low quality sources of CaO/Ca(OH).sub.2 and reduces consumption of high quality CaO/Ca(OH).sub.2 for this purpose.

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.

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.

A method for preparing xanthate by a slurry method includes steps of: adding a mixture of dichloromethane and carbon disulfide as a reaction solvent in a slurry reactor, and then adding alcohol and caustic alkali to react with carbon disulfide under less than 1 atm to remove heat released by the reaction by evaporating the solvent; performing vacuum distillation after the reaction to remove the solvent and water, so as to obtain the xanthate; transporting the xanthate to a granulation equipment for granulating, and then drying in a drying equipment to obtain a product. The method is performed in a system formed by a reaction equipment, a solvent recovery equipment, the granulation equipment, and the drying equipment, wherein a main equipment of the reaction system is a slurry reactor. The method has advantages of high efficiency, low energy consumption, good safety, environmental friendliness, convenient operation and the like.

A method for preparing xanthate by a slurry method includes steps of: adding a mixture of dichloromethane and carbon disulfide as a reaction solvent in a slurry reactor, and then adding alcohol and caustic alkali to react with carbon disulfide under less than 1 atm to remove heat released by the reaction by evaporating the solvent; performing vacuum distillation after the reaction to remove the solvent and water, so as to obtain the xanthate; transporting the xanthate to a granulation equipment for granulating, and then drying in a drying equipment to obtain a product. The method is performed in a system formed by a reaction equipment, a solvent recovery equipment, the granulation equipment, and the drying equipment, wherein a main equipment of the reaction system is a slurry reactor. The method has advantages of high efficiency, low energy consumption, good safety, environmental friendliness, convenient operation and the like.

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.

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.