An agent for initiating a radical addition reaction includes a persulfate and one or more transition metals, in elemental form or in an oxidized form, as well as a method for preparing a compound of formula (I)

##STR00001## in which X is selected from S, Se and O; by a radical addition reaction in the presence of such an agent.

A solubility enhancing aqueous composition comprising a first solution comprising an anionic component comprising sulfate ions, alone or in combination with bisulfate ions, having a concentration from about 8.00 moles per liter to about 13.00 moles per liter of the first solution volume, and a cationic comprising ammonium ions having a concentration from about 1.45 moles per liter to about 2.01 moles per liter of the first solution volume, combined with a volume of water at least equal to the volume or weight of the first solution forming a second solution is provided. Variations of this general composition are also provided. The compositions are useful for enhancing solubility of a variety of molecules, typically metal ions.

A solubility enhancing aqueous composition comprising a first solution comprising an anionic component comprising sulfate ions, alone or in combination with bisulfate ions, having a concentration from about 8.00 moles per liter to about 13.00 moles per liter of the first solution volume, and a cationic comprising ammonium ions having a concentration from about 1.45 moles per liter to about 2.01 moles per liter of the first solution volume, combined with a volume of water at least equal to the volume or weight of the first solution forming a second solution is provided. Variations of this general composition are also provided. The compositions are useful for enhancing solubility of a variety of molecules, typically metal ions.

There is provided herein a fertilizer granule comprising Urea, Polyhalite and Ammonium Sulphate.

The present invention relates to the processing of natural titanium-containing feedstock, mainly ilmenite concentrate, including ilmenite ores with a low TiO.sub.2 content, into products with high added value without generating any liquid or solid waste. The method according to the invention comprises the following stages: digesting ilmenite concentrate, processing the solid residue following ilmenite concentrate digestion, hydrolysis of titanium oxychloride, washing titanium oxides/hydroxides precipitate from impurities, calcination of titanium oxides/hydroxides precipitate, precipitation of iron hydroxides to obtain black, red and yellow iron oxide pigments, processing the mother liquor containing calcium chloride, regeneration of hydrogen chloride from ammonium chloride solution, obtaining ammonium sulfate and ammonium sulfate crystallization, obtaining crystalline ammonium chloride. The resulting products are pigments, pigment fillers, mineral fertilizers, construction materials, raw materials for the production of metals, and other products; they are used in various fields of application such as paint and coatings industry, pulp and paper industry, in the production of plastics, in metallurgy, in agricultural, construction industries and others.

A method for preparing a cathode active material precursor for a secondary battery, including: moving a co-precipitation filtrate generated after a co-precipitation reaction to a co-precipitation filtrate storage tank; removing a metal hydroxide by passing the co-precipitation filtrate through a filter; reacting the co-precipitation filtrate from which the metal hydroxide is removed with sulfuric acid or nitric acid to produce an ammonium sulfate or an ammonium nitrate while removing ammonia from the co-precipitation filtrate from which the metal hydroxide is removed; cooling and crystallizing the co-precipitation filtrate from which the metal hydroxide and ammonia are removed to precipitate a sodium sulfate; filtering the precipitated sodium sulfate to separate the precipitated sodium sulfate from the co-precipitation filtrate from which the metal hydroxide and ammonia are removed; drying the sodium sulfate separated from the co-precipitation filtrate and moving the co-precipitation filtrate separated from the sodium sulfate to a circulation concentration tank; and heating the co-precipitation filtrate stored in the circulation concentration tank to a predetermined temperature for recycling and performing N.sub.2 purging or bubbling, is provided.

A method for preparing a cathode active material precursor for a secondary battery, including: moving a co-precipitation filtrate generated after a co-precipitation reaction to a co-precipitation filtrate storage tank; removing a metal hydroxide by passing the co-precipitation filtrate through a filter; reacting the co-precipitation filtrate from which the metal hydroxide is removed with sulfuric acid or nitric acid to produce an ammonium sulfate or an ammonium nitrate while removing ammonia from the co-precipitation filtrate from which the metal hydroxide is removed; cooling and crystallizing the co-precipitation filtrate from which the metal hydroxide and ammonia are removed to precipitate a sodium sulfate; filtering the precipitated sodium sulfate to separate the precipitated sodium sulfate from the co-precipitation filtrate from which the metal hydroxide and ammonia are removed; drying the sodium sulfate separated from the co-precipitation filtrate and moving the co-precipitation filtrate separated from the sodium sulfate to a circulation concentration tank; and heating the co-precipitation filtrate stored in the circulation concentration tank to a predetermined temperature for recycling and performing N.sub.2 purging or bubbling, is provided.

There is provided herein a fertilizer granule comprising Urea, Polyhalite and Ammonium Sulphate.

Methods for processing pretreated phosphogypsum wastewater are disclosed. Precipitation of select constituents may be promoted to control a hardness level of the pretreated wastewater. Ammonia may then be removed from the process stream via reverse osmosis. A membrane contactor and/or polishing unit(s) may optionally be used. Related systems are also disclosed.

Methods for processing pretreated phosphogypsum wastewater are disclosed. Precipitation of select constituents may be promoted to control a hardness level of the pretreated wastewater. Ammonia may then be removed from the process stream via reverse osmosis. A membrane contactor and/or polishing unit(s) may optionally be used. Related systems are also disclosed.