A method for complex treatment of phosphogypsum comprising crushing of phosphogypsum and its washing with a solution of sulphuric acid, concentration 2-15%, and stirring at 50-80 C., wherein the resultant mixture is separated into a liquid fraction and a sediment containing mostly calcium sulphate, which is characterized in that metals are precipitated from the liquid fraction, mainly lanthanides, phosphates and sulphates of metals soluble in diluted sulphuric acid, and the sediment containing mostly calcium sulphate is converted in the presence of ammonia liquor and carbon dioxide to ammonium sulphate and calcium carbonate, wherein filtered and dried sediment of calcium carbonate is dissolved in a 15-30% solution of nitric acid while stirring continuously, and then the resultant CO.sub.2 is recirculated and used in the conversion of the first phase of the sediment, and the resultant mixture is separated into a solution of calcium nitrate with dissolved metals and a sediment of fluorides and silicates with metal precipitate.

A method for complex treatment of phosphogypsum comprising crushing of phosphogypsum and its washing with a solution of sulphuric acid, concentration 2-15%, and stirring at 50-80 C., wherein the resultant mixture is separated into a liquid fraction and a sediment containing mostly calcium sulphate, which is characterized in that metals are precipitated from the liquid fraction, mainly lanthanides, phosphates and sulphates of metals soluble in diluted sulphuric acid, and the sediment containing mostly calcium sulphate is converted in the presence of ammonia liquor and carbon dioxide to ammonium sulphate and calcium carbonate, wherein filtered and dried sediment of calcium carbonate is dissolved in a 15-30% solution of nitric acid while stirring continuously, and then the resultant CO.sub.2 is recirculated and used in the conversion of the first phase of the sediment, and the resultant mixture is separated into a solution of calcium nitrate with dissolved metals and a sediment of fluorides and silicates with metal precipitate.

A device for producing granules that include ammonium sulfate may include a mixing device, an atomizing device and a fluidized bed. The mixing device may be utilized to produce a composition comprising ammonium sulfate and aluminum sulfate. The atomizing device may be disposed downstream of the mixing device and may be utilized to atomize the composition produced in the mixing device. The fluidized bed may also be disposed downstream of the mixing device. The fluidized bed may be utilized for producing the granules. Further, with respect to a process for producing granules comprising ammonium sulfate, a step of granulating a composition comprising ammonium sulfate and aluminum sulfate may involve providing ammonium sulfate-containing nuclei, fluidizing the ammonium sulfate-containing nuclei, and atomizing the composition onto the nuclei.

A device for producing granules that include ammonium sulfate may include a mixing device, an atomizing device and a fluidized bed. The mixing device may be utilized to produce a composition comprising ammonium sulfate and aluminum sulfate. The atomizing device may be disposed downstream of the mixing device and may be utilized to atomize the composition produced in the mixing device. The fluidized bed may also be disposed downstream of the mixing device. The fluidized bed may be utilized for producing the granules. Further, with respect to a process for producing granules comprising ammonium sulfate, a step of granulating a composition comprising ammonium sulfate and aluminum sulfate may involve providing ammonium sulfate-containing nuclei, fluidizing the ammonium sulfate-containing nuclei, and atomizing the composition onto the nuclei.

The present invention provides a continuous process for producing ammonium sulfate crystals, wherein said process comprises: (a) feeding to a first group of crystallization sections, which crystallization sections are heat integrated in series, a first aqueous ammonium sulfate solution that contains one or more impurities; (b) feeding to a second group of crystallization sections, which crystallization sections are heat integrated in series, a second aqueous ammonium sulfate solution that contains one or more impurities; (c) crystallizing ammonium sulfate crystals in each crystallization section respectively from each of said solutions of ammonium sulfate that contain one or more impurities; (d) purging a fraction of the ammonium sulfate solution that contains one or more impurities from each of said crystallization sections; and (e) discharging ammonium sulfate crystals from each crystallization section, characterized in that: (i) both the first group of crystallization sections and the second group of crystallization sections are together heat integrated in one series of crystallization sections; wherein the first group of crystallization sections operates at higher temperature than the second group of crystallization sections; and (ii) the composition of the first aqueous ammonium sulfate solution that contains one or more impurities is different to the composition of the second aqueous ammonium sulfate solution that contains one or more impurities. Further provided is apparatus suitable for producing ammonium sulfate crystals.

The present invention provides a continuous process for producing ammonium sulfate crystals, wherein said process comprises: (a) feeding to a first group of crystallization sections, which crystallization sections are heat integrated in series, a first aqueous ammonium sulfate solution that contains one or more impurities; (b) feeding to a second group of crystallization sections, which crystallization sections are heat integrated in series, a second aqueous ammonium sulfate solution that contains one or more impurities; (c) crystallizing ammonium sulfate crystals in each crystallization section respectively from each of said solutions of ammonium sulfate that contain one or more impurities; (d) purging a fraction of the ammonium sulfate solution that contains one or more impurities from each of said crystallization sections; and (e) discharging ammonium sulfate crystals from each crystallization section, characterized in that: (i) both the first group of crystallization sections and the second group of crystallization sections are together heat integrated in one series of crystallization sections; wherein the first group of crystallization sections operates at higher temperature than the second group of crystallization sections; and (ii) the composition of the first aqueous ammonium sulfate solution that contains one or more impurities is different to the composition of the second aqueous ammonium sulfate solution that contains one or more impurities. Further provided is apparatus suitable for producing ammonium sulfate crystals.

A method for producing a dry reagent composition includes preparing a reagent solution including a Good's buffer in a concentration of more than 2.5 mM, an ammonium salt, a drying protection agent, and a nucleic acid amplification enzyme, and drying the reagent solution. A method for suppressing a decrease in enzyme activity during drying includes adding a Good's buffer in a biochemical reagent comprising an ammonium salt and an enzyme prior to drying the enzyme.

A method for producing a dry reagent composition includes preparing a reagent solution including a Good's buffer in a concentration of more than 2.5 mM, an ammonium salt, a drying protection agent, and a nucleic acid amplification enzyme, and drying the reagent solution. A method for suppressing a decrease in enzyme activity during drying includes adding a Good's buffer in a biochemical reagent comprising an ammonium salt and an enzyme prior to drying the enzyme.

Provided herein are methods comprising a) treating a slag solid or carbide lime suspension with an ammonium salt in water to produce an aqueous solution comprising calcium salt, ammonium salt, and solids; b) contacting the aqueous solution with carbon dioxide from an industrial process under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the precipitation material and the supernatant aqueous solution comprise residual ammonium salt; and c) removing and optionally recovering ammonia and/or ammonium salt using one or more steps of (i) recovering a gas exhaust stream comprising ammonia during the treating and/or the contacting step; (ii) recovering the residual ammonium salt from the supernatant aqueous solution; and (iii) removing and optionally recovering the residual ammonium salt from the precipitation material.

A process for producing one or more products from a lignocellulosic feedstock comprising treating the lignocellulosic feedstock to produce sugar in one or more stages comprising addition of acid, base or a combination thereof and introduction of heat. The addition of the acid, base, or a combination thereof produces a salt. The sugar is fermented to produce a fermentation product and the fermentation product is recovered. A stream comprising the salt is treated by wet oxidation with the introduction of heat. A stream comprising salt resulting from the wet oxidation is provided for use as a salt product or a process chemical for introduction within the process. Heat from the wet oxidation may be supplied to any stage of the process in which heat is introduced.