Abstract: In a method for treating waste water containing ammonium salts, sodium sulfate crystal is obtained by freezing crystallization, then the pH value of the waste water is adjusted to a specific range, and next sodium chloride crystal and ammonia water is obtained by evaporation. Alternatively, the pH value of the waste water is adjusted to a specific range, then sodium chloride crystal and ammonia water is obtained by evaporation, and next sodium sulfate crystal is obtained by freezing crystallization. This method can recover ammonia, sodium sulfate, and sodium chloride from the waste water.

Abstract: A system and method for passive capture of ammonia in an enclosure containing material that gives off ammonia. The invention allows for the passage of gaseous NH3 through microporous hydrophobic gas-permeable membranes and its capture in a circulated acidic solution with concomitant production of a concentrated non-volatile ammonium salt.

Abstract: Processes for recovering ammonia from an ammonium sulfate stream include reacting the ammonia sulfate stream with a lime slurry to form a slurry comprising calcium sulfate and ammonia; providing the slurry comprising calcium sulfate and ammonia to a stripper configured to recover the ammonia from the slurry; utilizing a heat source from a chilled ammonia process to the stripper; and extracting an ammonia vapor stream from the stripper. Also disclosed are systems for performing the processes.

Abstract: Processes for recovering ammonia from an ammonium sulfate stream include reacting the ammonia sulfate stream with a lime slurry to form a slurry comprising calcium sulfate and ammonia; providing the slurry comprising calcium sulfate and ammonia to a stripper configured to recover the ammonia from the slurry; utilizing a heat source from a chilled ammonia process to the stripper; and extracting an ammonia vapor stream from the stripper. Also disclosed are systems for performing the processes.

Abstract: Provided is a fixation method of carbon dioxide. The method includes a) grinding waste gypsum to become 200˜300 mesh; b) performing reaction by supplying mixed gas while mixing the ground waste gypsum with aqueous ammonia, and c) separating solid from liquid in the manufactured slurry by centrifugation and drying separated solid and liquid portions with calcite and ammonium sulfate, wherein the mixed gas is formed of nitrogen and carbon dioxide, and the carbon dioxide provides carbon dioxide fixation method containing 5˜25 wt %. When carbon dioxide is fixed by using waste gypsum, reaction efficiency is remarkably high. The fixation method makes more than 95% of supplied carbon dioxide fixed. Also, provided is an economical method that disposes carbon dioxide as a disposal target without its separation, refinement and liquefaction processes, to thereby remarkably reduce the entire process and costs for processes.

Abstract: A method for sequestering carbon dioxide (CO2) that includes generating ammonia from an ammonium salt to make a basic ammoniated aqueous solution and using the solution to remove at least a portion of CO2 from a CO2-bearing gas and precipitate the removed CO2 as bicarbonate. The aqueous solution is recycled. Various valuable byproducts, including sodium bicarbonate, sodium carbonate, ammonium bicarbonate, and hydrochloric acid, are produced. Ammonia is generated by reacting an ammonium salt with either acidic or basic materials. Non-limiting examples of suitable ammonium salt include ammonium chloride, ammonium sulfate, ammonium bisulfate, and ammonia nitrate, those of the acidic material include ammonium bisulfate and sulfuric acid, and those of the basic material include calcium oxide, limestone, dolomite, cement kiln dust, calcium-rich fly ash, steel and iron slag, and silicate rocks or mining wastes that are rich in serpentine, olivine or wollastonite.

Abstract: The present invention provides an improved process for the preparation of MgO of high purity >99% from salt bitterns via intermediate formation of Mg(OH)2 obtained from the reaction of MgCl2 and lime, albeit indirectly, i.e., MgCl2 is first reacted with NH3 in aqueous medium and the slurry is then filtered with ease. The resultant NH4Cl-containing filtrate is then treated with any lime, to regenerate NH3 while the lime itself gets transformed into CaCl2 that is used for desulphatation of bittern so as to recover carnallite and thereafter MgCl2 of desired quality required in the present invention. The crude Mg(OH)2 is dried and calcined directly to produce pure MgO, taking advantage of the fact that adhering impurities in the Mg(OH)2 either volatilize away or get transformed into the desired product, i.e., MgO.

Abstract: In one embodiment, an ammonium removal method can comprise: removing a multivalent cation from a stream comprising ammonium to form a treated stream; converting the ammonium in the stream to ammonia by increasing the pH of the stream; and separating the ammonia from the treated stream to form a separated stream and gaseous ammonia. In another embodiment, an ammonium removal method can comprise: a multivalent cation from a stream comprising ammonium to form a treated stream comprising a total of less than or equal to about 50 ppm by weight of multivalent cations; increasing the pH of the stream to a conversion pH; converting the ammonium to ammonia; and separating the ammonia from the treated stream to form a separated stream and gaseous ammonia.

Abstract: A process for reclaiming ammonia from waste streams comprises reacting at least one waste stream with an excess of hydroxide to produce ammonia and water. The ammonia is removed from the reaction vessel and purified.

Abstract: The present invention relates to zeolites having the crystal structure of chabazite (CHA) and having small crystallite size, to processes using the small crystallite CHA as a catalyst, and to gas separation processes using the small crystallite CHA.

Abstract: A process is provided for preparing ammonium metavanadate from the combustion ashes resulting from the combustion of petroleum fuels in a boiler by using the ammonium sulfate and vanadium components in the combustion ash. Water is added to the combustion ash to form a slurry. The solids are removed from the slurry. Ammonia and an oxidizing gas, such as air, oxygen or ozone, are added to the aqueous solution obtained from the slurry to oxidize the vanadium, thereby producing an aqueous solution containing ammonium metavanadate. The ammonium metavanadate is crystallized and recovered from the aqueous solution. Calcium hydroxide or calcium oxide is injected into the aqueous solution and reacts with the ammonium sulfate to produce gypsum and ammonia. This gypsum and ammonia containing solution is flowed down a packed column, where it is counter-currently contacted with air or steam which strips the ammonia out of the solution.

Abstract: A process is provided for producing potassium sulfate by reacting ammonium sulfate and potassium chloride at a temperature of about 30 to 40° C. to produce a slurry containing K2SO4·NH4·2SO4 double salt, and reacting this double salt with an aqueous solution containing potassium chloride at a temperature of about 30° C. to produce a slurry containing potassium sulfate. The slurry containing potassium sulfate is subjected to a solids/liquid separation step to obtain potassium sulfate crystals having a size in the range of about 20 mesh to about 150 mesh.

Abstract: A method for removing ammonia from coal fly ash contaminated by ammonium salts is disclosed. The method involves the addition of small amounts of water, and in some cases, small amounts of an alkali source, to the fly ash to liberate the ammonia trapped therein. The ammonia liberation may be further aided by vigorous mixing of the fly ash.

Abstract: A method is provided for treating ashes from the combustion of petroleum fuels by mixing the combustion ashes with water to produce a slurry; injecting either calcium oxide or calcium hydroxide into the slurry and reacting the calcium oxide or calcium hydroxide with the ammonium sulfate within the ashes to produce a slurry containing gypsum and ammonia; flowing the slurry containing gypsum and ammonia down from the top portion of packed column and air or steam up from the bottom portion of the packed column so that the air or steam strips the ammonia from the gypsum slurry; and separating the gypsum from the resulting ammonia-free slurry using a solid/liquid separator.

Abstract: A method for producing potassium carbonate using a continuous countercurrent exchange system. A continuous ion exchange system with resin in the ammonium form is flushed with a saturated potassium chloride solution which displaces the ammonium ion and replaces it with potassium. Ammonium carbonate is then passed through the ion exchanger to place the ammonium in the reserve form, by displacing the potassium, and produce a concentrated potassium carbonate solution. This process is done in a continuous countercurrent manner which allows maximum recovery of the potassium carbonate as a 15-18% by weight solution with minimum impurities, and at high throughput rates. The potassium carbonate solution is then removed, evaporated, dried, sized and stored for subsequent shipment.

Abstract: A process for the removal and recovery of ammonia from liquid waste, characterized essentially by the following operations:reacting the liquid waste with pure carbon dioxide, or with a gaseous mixture rich in carbon dioxide, or with at least one carbonate, to give ammonium carbonatereacting the resulting ammonium carbonate with calcium chloride to give calcium carbonate and ammonium chloride;causing the resulting calcium carbonate to undergo thermal decomposition to give calcium oxide and carbon dioxide;using, optionally, the carbon dioxide formed after thermal decomposition of calcium carbonate for said reaction with the liquid waste; andusing the calcium oxide, formed after thermal decomposition of calcium carbonate, for the production of pure ammonia, by reaction with the ammonium chloride obtained in said reaction between ammonium carbonate and calcium chloride.The figure shows a flow sheet of a plant allowing the operations of an embodiment of the above process.

Abstract: For reducing nitrogen oxides in the flue gases of a firing plant, fresh ammonia water, i.e. an aqueous solution of ammonia (NH.sub.3), is introduced into the flue gas flow. For achieving a high degree of separation of the nitrogen oxide a superstoichiometric addition of ammonia (NH.sub.3) is necessary. Most of the excess ammonia is washed out in the wet washer (6). A liquor, e.g. milk of lime (Ca(OH).sub.2), is dosed into the wash water in a connecting line (10) to a stripping column (11), so that a pH-value above 9.5 is obtained. The now physically dissolved ammonia (NH.sub.3) is desorbed from the wash water in the stripping column (11). The steam/ammonia mixture passing out of the stripping column (11) is condensed in a condenser (17) and the condensate in the form of ammonia water is admixed to the fresh ammonia water in feed line (3). As a function of the nitrogen oxide reduction, approximately 10 to 50% of the fresh ammonia water can be saved.

Abstract: A process for producing high grade silica and fluorine-containing coproducts from fluosilicic acid is described. To produce silica, the fluosilicic acid is reacted with aqueous ammonia to produce a solid silica product and a solution of ammonium fluoride. The solid silica is washed under controlled conditions and further processed to produce a high grade product. The ammonium fluoride solution is concentrated and sold as a concentrated ammonium fluoride solution product or reacted with metal hydoxides or oxides to produce metal fluorides.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from wastewaters such as coke-plant or coal conversion wastewaters. The process involves adding alkali to these wastewaters in amounts sufficient to react with fixed ammonia salts present in the wastewater and to enable substantial amounts of the ammonia to be evolved upon distillation, and subjecting the thus treated wastewater to distillation to remove substantial amounts of the ammonia and acid gases present from the wastewater. This process is achieved by two separate and successive distillations. In this process, the vapor streams being withdrawn from the first and/or second distillations are subjected to an impurity removal process to thereby produce a vapor stream substantially reduced in impurities, and useful as a stripping vapor in this process, and then reusing this vapor stream as a stripping vapor in the process.

Abstract: A process and system are disclosed for the bridging of operational standstills of an ammonia washer of a plant operating according to the semi-direct technique for the removal of ammonia from coking oven gas. During the operational standstills of the ammonia washer, the ammonia is washed out from the coking oven gas in a secondary cooler constituting three parts, an upper part (Wash Stage I) provided with stripped water from an ammonia still, a middle part (wash stage II) provided with gas water, and a lower part (wash stage III) provided with circulation water. All of the waters provided for the secondary cooler are collected in its sump, and after a separation of the circulation water necessary for the Wash Stage III, it is split into two partial streams, one serving for the recovery of stripped water for Wash Stage I and which is led into an ammonia still provided only with water vapor and the other partial stream is led into an ammonia still provided with water vapor and alkali.

Abstract: An apparatus for granulation of precipitation products, comprising a liquid-filled reaction chamber including a granulation chamber which receives aqueous streams of compounds which precipitate to form granules. The granulation chamber has an open upper edge connected to the narrow edge of a conical surface. The upper open edge of the conical surface merges with an apron which is spaced inwardly from the inner periphery of the reaction chamber. Conduit means conduct granules downwardly from the granulation chamber. Liquid and fine granules rise upwardly within the conical surface. Granules descend back into the granulating chamber. Clean liquid passes downwardly through the annular space between the apron and the reaction chamber for removal from the space between the conical surface and the apron.

Abstract: A process for the substantially complete removal of acid gases and ammonia from aqueous solutions is disclosed, which comprises a two stage distillation operation wherein the pressure in the first distillation stage is substantially less than the pressure in the second stage, the ammonia concentration in this stage decreases downwardly so that an aqueous bottoms stream has a pH less than 8, this aqueous bottoms stream is treated with alkali and then distilled in the second stage. A portion of the aqueous bottoms can be vaporized by indirect heat exchange with vapors evolving from the second stage. The improvement lies in adding ammonia to the overhead vapor from the first stage to reduce corrosion of the condenser and preferably, the amount of vapor condensed is controlled to further minimize corrosion.

Abstract: Fixed ammonia in an aqueous stream is converted to free ammonia in solution by mixing the stream with a lime slurry in a mixing zone. The resulting liquid mixture is heated by contact with steam-containing gas to a temperature of at least about 95.degree. C. to form a heated liquid mixture containing free ammonia in solution and an ammonia-rich product vapor. A portion of the heated liquid mixture is withdrawn and is contacted with steam in a packed stripping zone to produce liquid waste and vapor containing free ammonia and steam. At least a portion of the vapor from the stripper is used as steam-containing gas for heating the liquid mixture. Ammonia is recovered from ammonia-rich product vapor withdrawn from the mixing zone.

Abstract: Ammonia or an amine such as morpholine is recovered from a resin bed comprising an alkali metal, e.g., sodium, and ammonium or amine salts of a strong acid cation exchange resin by contacting the cation resin with an aqueous solution of an alkaline earth metal hydroxide, e.g., calcium hydroxide, thereby exchanging the alkali metal and ammonium or amine cations with alkaline earth metal cations. The aqueous liquid containing the alkali metal and ammonia or amine is subsequently passed through a cation exchange resin which removes the alkali metal from the liquid. The recovery of ammonia or the amine by such method is particularly useful in condensate purification system associated with a power production facility wherein the recovered ammonia or amine can be employed to reduce corrosion in the power production facility and the strong acid resin, upon regeneration, can be used to remove alkali metal ions, particularly sodium, from the facility.

Abstract: A process is described for the removal of acid gases and ammonia from dilute aqueous solutions. This is achieved by two separate and successive distillations. In the first distillation, substantially all of the acid gases and free ammonia are removed. In the second distillation, substantially all of the fixed ammonia is removed. Exemplary aqueous solutions are waste waters from coke oven and coal conversion plants.

Abstract: Radiation-contaminated ammonium nitrate is heated in solution to about 100.degree. C. in the presence of finely powdered calcium oxide or lithium hydroxide. Ammonia and water vapor are given off leaving an alkaline or alkaline earth nitrate which can then be safely decomposed by calcination into a metal oxide and oxides of nitrogen. The metal oxide can be recycled in a continuation of the process. The oxides of nitrogen can be passed through water to produce nitric acid useable in dissolving oxides of fissionable materials and the ammonia may be used in aqueous solution to react with nitrates of nuclear fuel or breeder metals in the very process that produces the by-product ammonium nitrate. Thus, all by-products and reagents can be reconverted and recycled.

Abstract: An improved process for obtaining copper from a copper sulfide, in which: the copper sulfide is treated with oxygen and an aqueous leaching solution of ammonium carbonate, to form a leach liquor which contains ammonia complexes of copper sulfate and copper carbonate; the leach liquor is heated to form gaseous ammonia and carbon dioxide; the leach liquor is treated with a strongly alkaline material to precipitate sulfates and form additional gaseous ammonia; and the copper is then recovered by electrowinning. In this process, the ammonium carbonate leaching solution is formed from carbon dioxide that is generated by: adding a metal carbonate to the leach liquor during the heating thereof; and recovering the gaseous carbon dioxide, as well as the gaseous ammonia, formed during the heating of the leach liquor.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantially all of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantially all of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia. In the second distillation, the amount of fixed ammonia is substantially reduced.

Abstract: The fouling of ammonia stills which results from the clogging, particularly of the lower plates of the stills, with sludge and precipitates is eliminated by use of a calcium compound precipitation step followed by a clarification step prior to initiation of actual distillation.

Abstract: Fouling of an ammonia still, used for removal of ammonia from weak ammonia liquor derived from a coal coking operation, is alleviated by pre-precipitating insoluble calcium salts from the ammonia liquor by treatment of the liquor with lime prior to introduction into a single-leg still.

Abstract: A process for the production of high purity calcium thiosulfate by a metathesis reaction of ammonium thiosulfate and calcium hydroxide or calcium oxide is disclosed. Aqueous solutions of high purity calcium thiosulfate, in concentrations up to about 30% by weight, are prepared by removing substantially all of the co-product ammonia under conditions which minimize the decomposition of the thiosulfate ion. Heating the reaction mixture to a temperature of about the boiling point at atmospheric pressure is used to prepare aqueous solution of about 10% by weight calcium thiosulfate, and lower reaction temperatures are employed to prepare more concentrated aqueous solutions of calcium thiosulfate up to about 30% by weight, which is the saturation point.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantial amounts of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantial amounts of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia and is conducted at a pH of more than 9. In the second distillation, the amount of fixed ammonia is substantially reduced.

Abstract: Digester supernatants and/or liquors from sludge dewatering are reacted with an excess of an alkaline reagent having a stronger cation than the ammonium ion and the reaction product is separated into a solution containing aqueous ammonia and solids. The aqueous ammonia derived from the separation stage is heated by free steam under a lowered pressure to free ammonia in gaseous form. The ammonia as a gas, or adsorbed in water, or adsorbed in an acid, or as an acid salt is then mixed with conventionally dried sludge to increase the nitrogen content of the sludge from approximately 1-2 percent to as high as 10 percent.

Abstract: A method for the recovery of ammonia from liquor from the filters of ammonia-soda plants, which contains free ammonia and ammonium chloride. In this method the liquor is heated to release the free ammonia, and the remaining liquor is then treated successively in a prelimer with lime in an amount insufficient to decompose the whole part of the ammonium chloride and in a still with steam and an alkali metal hydroxide in an amount sufficient to decompose the remaining part of ammonium chloride.

Abstract: In a process for the preparation of lactam from cycloalkanone comprising reacting said alkanone with hydroxylamine sulfate to form the corresponding cycloalkanone oxime followed by Beckman rearrangement to yield said lactam and neutralization of the sulfuric acid formed by ammonia whereby ammonium sulfate is formed as a byproduct, the improvement which comprises reacting said ammonium sulfate with an alkaline-earth metal oxide or hydroxide to form an alkaline earth metal sulfate and ammonia, heating said alkaline-earth metal sulfate to decompose it into said alkaline-earth metal oxide and sulfur dioxide and/or sulfur trioxide, converting said sulfur dioxide and/or sulfur trioxide into sulfuric acid, whereby said sulfuric acid and said ammonia are capable of reuse in said process.