Methods for the production of ammonium sulfate nitrate include (a) providing at a temperature of less than about 175 °C a melt including ammonium nitrate, ammonium sulfate, and water and the water content is greater than about 2 wt % based on the total weight of ammonium nitrate, ammonium sulfate and water in the melt, and (b) solidifying from the melt 1:2 ANS double salt by cooling at least a portion of the melt at a rate of less than about 100 °C/min.

Methods for preparing compositions comprising ammonium nitrate double salts

The invention relates to a large-scale joint alkali-making circulation process. The process comprises the following steps: a. obtaining an alkali-making raw material by an infiltration alkali extraction method; b. obtaining hydrogen sulfide and methane by utilizing microbial resource in an alkali halide; c. evaporating and concentrating a thin alkali liquid by utilizing natural energy; d. obtaining various types of products by combining a natural alkaline method and a chemical combination method; e. obtaining subsidiary products by combing coal chemical industry deep processing and an alkali-making process; and f. obtaining series of products by combining an electrolytic process and a chemical combination method. The large-scale joint alkali-making circulation process has the beneficial effects that natural alkali waste resource and hidden resource are excavated for raw material supply, biological energy and natural energy are comprehensively utilized so as to realize energy utilization, potential of coal chemical industry deep processing is developed and an activated carbon purification technology is applied to low carbon economy so as to achieve the purposes of energy conservation and environmental friendliness so that technologies in various fields are tightly integrated with the alkali-making process, thus fundamentally realizing large-scale joint alkali-making circulation and greatly lowering the alkali-making cost.

Large-scale joint alkali-making circulation process

The invention relates to a method for producing sodium hydrogen carbonate and ammonium sulfate by using a sodium sulfate solution, and belongs to the technical field of chemical engineering. The method comprises the following steps: a, absorbing circulating gas by using the sodium sulfate solution at -5 to 10 DEG C to obtain absorbing liquid; b, mixing the absorbing liquid, ammonium hydrogen carbonate and/or mixed salt at -5 to 20 DEG C to obtain mixed slurry; c, performing sealed reaction on the mixed slurry to obtain sodium hydrogen carbonate and reaction mother liquid; d, mixing the reaction mother liquid and complex salt to obtain salt mixture and primary frozen mother liquid after freezing; e, distilling the primary frozen mother liquid to obtain carbon dioxide, ammonium circulating gas and ammonium steaming mother liquid; f, adjusting the ammonium steaming mother liquid by acid to obtain an acidified solution and gas; g, mixing and freezing the acidified solution and crystallizedmother liquid to obtain complex salt and secondary frozen mother liquid; and h, evaporating and concentrating the secondary frozen mother liquid to separate out ammonium sulfate. The method is low inenvironmental pollution and high in raw material utilization rate.

Method for producing sodium hydrogen carbonate and ammonium sulfate by using sodium sulfate solution

The invention relates to a method for producing a potassium-based fertilizer or a nitrogen-based fertilizer by a flue gas treatment process. Besides, the invention relates to a method for separating a fertilizer precursor from a flue gas flow. The method comprises an oxidation step including dry adsorbent operation, wet washing operation and removing air pollutants, a carbon dioxide trapping step and a sodium bicarbonate sedimentating step. The step comprising removal of the air pollutants is used for separating the precursor, and the precursor is used for fertilizer production. Besides, the invention relates to a method for removing carbon dioxide from the flue gas flow.

Method for purifying flue gas

The invention relates to methods for coproducing sodium carbonate and ammonium sulfate from melamine tail gas and mirabilite. The method for producing the sodium carbonate comprises the following steps of: a, providing a sodium sulfate water solution; b, introducing melamine tail gas into the sodium sulfate water solution to form an ammonium carbonate-sodium sulfate water solution; c, introducing carbon dioxide into the ammonium carbonate-sodium sulfate water solution to obtain a suspension serous fluid of sodium bicarbonate crystals; and d, carrying out solid and liquid separation on the suspension serous fluid to obtain sodium bicarbonate and a mother solution I, calcining sodium bicarbonate solid to obtain the sodium carbonate. The method further comprises the following steps of: e, adding the mother solution I into an ammonia stilling tower, heating, forming tower top mixed gas containing ammonia and carbon dioxide, generating a deamination solution in the tower; f, evaporating the deamination solution for dewatering to obtain sodium sulfate crystals and a mother solution II; g, cooling the mother solution II for crystallizing to obtain Na2SO4.(NH4)2SO4.4H2O salt crystals and a mother solution III; and h, evaporating the mother solution III for dewatering, and separating out ammonium sulfate crystals. The methods have the advantages of high utilization rate of raw materials and low energy consumption.

Methods for coproducing sodium carbonate and ammonium sulfate from melamine tail gas and mirabilite

A process for recovering sodium bicarbonate and ammonium sulfate from a sodium sulfate solution. The sodium sulfate solution can be pure or contain other compounds such as sodium sulfite, carbonate, chloride, fluoride, nitrate and nitrite as would be the case if the sodium sulfate solution were derived from a sodium bicarbonate flue gas purification process. Carbon dioxide and ammonia gases or solid ammonium bicarbonate are added to the sodium sulfate solution to precipitate sodium bicarbonate which is removed from solution. The remaining solution is treated in a unique series of precipitation steps in which reactants are first recycled back to the sodium bicarbonate crystallizer and then the amount of sodium in the solution is adjusted to an amount that allows high grade ammonium sulfate fertilizer product to be produced. The process is accomplished using evaporation and precipitation unit operations in a unique sequence that results in 100% conversion of the sodium salt feed stock to sodium bicarbonate and ammonium sulfate in a commercially viable manner.

Joe Calgary Bichel

Papers

Method for recovering purified sodium bicarbonate and ammonium sulfate