A particulate, urea-containing composition and use of an additive for producing a particulate, urea-containing composition and methods of producing a particulate, urea-containing composition.

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.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

A method for the management of phosphogypsum consists in that a reactor (2) is charged with apatite and/or phosphorite phosphogypsum and with an aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate from a pre-reactor (1), at 1: (0.1-4) ratio of phosphogypsum to the aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate, the entire contents are stirred at 10 C. to 200 C. for at least 2 minutes, CO.sub.2 being released in the course of the process is directed to the pre-reactor (1), and the post-reaction mixture is directed to a filter (3) to obtain an aqueous ammonium sulphate solution, whereas the precipitate from the filter (3) is heat-treated, followed by dissolving it in nitric acid in a reactor (5), and the resultant suspension is filtered through a filter (6) to obtain an aqueous calcium nitrate solution, and CO.sub.2 being released in the reactor (5) is recirculated to the pre-reactor (1) wherein CO.sub.2 is reacted with ammonia in an aqueous solution to obtain the aqueous or ammoniacal solution of carbonate and/or bicarbonate which is directed to the reactor (2), with the process for obtaining the aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate being conducted until the pH 7-12 of the solution is reached.

A method for the management of phosphogypsum consists in that a reactor (2) is charged with apatite and/or phosphorite phosphogypsum and with an aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate from a pre-reactor (1), at 1: (0.1-4) ratio of phosphogypsum to the aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate, the entire contents are stirred at 10 C. to 200 C. for at least 2 minutes, CO.sub.2 being released in the course of the process is directed to the pre-reactor (1), and the post-reaction mixture is directed to a filter (3) to obtain an aqueous ammonium sulphate solution, whereas the precipitate from the filter (3) is heat-treated, followed by dissolving it in nitric acid in a reactor (5), and the resultant suspension is filtered through a filter (6) to obtain an aqueous calcium nitrate solution, and CO.sub.2 being released in the reactor (5) is recirculated to the pre-reactor (1) wherein CO.sub.2 is reacted with ammonia in an aqueous solution to obtain the aqueous or ammoniacal solution of carbonate and/or bicarbonate which is directed to the reactor (2), with the process for obtaining the aqueous or ammoniacal solution of ammonium carbonate and/or bicarbonate being conducted until the pH 7-12 of the solution is reached.

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.