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: The present invention relates to a method for obtaining a plurality of combustible gases from a rock and producing energy using the combustible gases. The method allows the utilization of shale rocks which are practically just waste, and enables producing a plurality of hydrocarbons in an aerobic condition. Obtaining combustible gases using the method disclosed in the present invention reduces the usage of fossil fuels. Thus, it is more environment-friendly compared to using fuels.

Abstract: The present disclosure provides a method for preparing a caprolactam and the method includes steps of subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; neutralizing the rearrangement mixture and extracting the neutralized rearrangement mixture using an organic solvent sequentially; and subjecting the extracted organic solution to a hydrogenation reaction so as to simplify the process to produce a high quality caprolactam.

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: Disclosed are methods and apparatus for providing an ammonia feed for a low-temperature process. The process includes two defined stages, gasification and hydrolysis. In a first stage thermal reactor, an aqueous urea solution is fed to a gasification chamber and heated gases are controlled in response to demand from a low temperature process requiring ammonia. The heated gases and aqueous urea are introduced into the gasification chamber upstream to fully gasify the solution of aqueous urea to a first stage gas stream comprising ammonia and isocyanic acid. The first stage gas stream is withdrawn and maintained hot enough to prevent solids formation. All amounts of urea feed, water and heated gases fed into the first stage thermal reactor are monitored and adjusted as necessary to achieve efficient hydrolysis in the second stage hydrolysis reactor. The second stage gas stream is withdrawn from the second stage reactor responsive to demand from a low temperature process requiring ammonia.

Abstract: A method of forming composition-modified barium titanate ceramic particulate includes mixing a plurality of precursor materials and a precipitant solution to form an aqueous suspension. The plurality of precursors include barium nitrate, titanium chelate, and a metal or oxometal chelate. The precipitant solution includes tetraalkylammonium hydroxide and tetraalkylammonium oxalate. The method further includes treating the aqueous suspension at a temperature of at least 150° C. and a pressure of at least 200 psi, and separating particulate from the aqueous suspension after treating.

Abstract: Molybdic oxide is recovered from molybdenite by a multistep process in which (A) the molybdenite is converted to soluble and insoluble molybdic oxide by pressure oxidation, (B) the insoluble molybdic oxide is converted to soluble molybdic oxide by alkaline digestion and then combined with the soluble molybdic oxide, and (C) the molybdenum values of the combined streams are extracted into an organic phase using a nonprimary amine. The extracted molybdenum values are recovered from the organic phase using aqueous ammonia to form ammonium dimolybdate (ADM) which is recovered as refined crystals from a two-step calcination process.

Abstract: Two classes of hybrid/thermochemical water splitting processes for the production of hydrogen and oxygen have been proposed based on (1) metal sulfate-ammonia cycles (2) metal pyrosulfate-ammonia cycles. Methods and systems for a metal sulfate MSO4—NH3 cycle for producing H2 and O2 from a closed system including feeding an aqueous (NH3)4SO3 solution into a photoctalytic reactor to oxidize the aqueous (NH3)4SO3 into aqueous (NH3)2SO4 and reduce water to hydrogen, mixing the resulting aqueous (NH3)2SO4 with metal oxide (e.g.

Abstract: The methods are utilized to recover ammonium from waste water using CO2 acidified absorption water. The process is particularly suited for utilization of cellular matter and a CO2 rich tail gas from a syngas fermentation process and derives significant benefit from the recovery of ammonium bicarbonate and ammonium carbonate. Ammonia and ammonium are recovered from the treatment of the syngas as an ammonium rich solution, at least a portion of which is recycled to the fermentation zone to aid in the production of liquid products. A carbon dioxide rich gas produced by fermentation is used to capture the ammonia and ammonium, forming the ammonium rich solution.

Abstract: The processes are utilized to recover ammonium from waste water using CO2 acidified absorption water. The process is particularly suited for utilization of cellular matter and a CO2 rich tail gas from a syngas fermentation process and derives significant benefit from the recovery of ammonium bicarbonate and ammonium carbonate. Ammonia and ammonium are recovered from the treatment of the syngas as an ammonium rich solution, at least a portion of which is recycled to the fermentation zone to aid in the production of liquid products. A carbon dioxide rich gas produced by fermentation is used to capture the ammonia and ammonium, forming the ammonium rich solution.

Abstract: To provide a sustainable method for the synthesis of ammonia from nitrogen by low resources and low energy. The present invention is a method for the synthesis of ammonia by a thermochemical cycle, which uses nitrogen and water as raw materials and uses renewable energy as an energy source. Ammonia is synthesized without auxiliary raw materials by a step of obtaining ammonia by a reaction of nitrogen and a halogenated hydrogen by way of a halogenated ammonium as a cycle that proceeds in a thermodynamic manner, and a step of recycling the byproduced halogen.

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: The present invention relates to a process for the recovery of ammonia contained in a gaseous stream, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing with an aqueous washing solution having a pH lower than 7.0, with the formation of a purified gaseous stream and an aqueous solution containing an ammonium salt; (b) treating the aqueous solution containing the ammonium salt coming from phase (a) in a vertical falling film heat exchanger at a temperature from 50 to 250° C. and an absolute pressure ranging from 50 KPa to 4 MPa with the formation of a regenerated washing solution and a gaseous stream comprising NH3 and H2O; (c) recycling said regenerated washing solution to phase (a). The present invention also relates to equipment for effecting the above process.

Abstract: A catalyst charge for ammonia oxidation, including the Andrussow process, comprises a first stage ammonia oxidation catalyst capable of oxidizing 20 to 99% of designed ammonia throughput, to produce a first stage product gas comprising unreacted ammonia, oxygen and nitrogen oxides, and a second stage ammonia oxidation catalyst capable of completing the oxidation of unreacted ammonia. Low levels of nitrous oxide are produced an extended campaign lengths may be seen.

Abstract: Proppants which can be used to prop open subterranean formation fractions are described. Proppant formulations which use one or more proppants of the present invention are described, as well as methods to prop open subterranean formation fractions, and other uses for the proppants and methods of making the proppants.

Abstract: Wet-chemical methods involving the use of water-soluble hydrolytically stable metal-ion chelate precursors and an ammonium oxalate precipitant can be used in a coprecipitation procedure for the preparation of ceramic powders. Both the precursor solution and the ammonium oxalate precipitant solution are at neutral or near-neutral pH. A composition-modified barium titanate is one of the ceramic powders that can be produced. Certain metal-ion chelates can be prepared from 2-hydroxypropanoic acid and ammonium hydroxide.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous purging stream produced in a synthesis process of urea, comprising the following phases: a) subjecting the gaseous purging stream to a washing with an aqueous acidic solution, at a pH ranging from 1 to 6, with the formation of a first purified gaseous stream and an aqueous solution containing an ammonium salt; b) subjecting the aqueous solution containing the ammonium salt coming from phase a) to stripping, after treatment with a strong base, at a temperature ranging from 50 to 250° C.

Abstract: Wet-chemical methods involving the use of water-soluble hydrolytically stable metal-ion chelate precursors and the use of a nonmetal-ion-containing strong base can be used in a coprecipitation procedure for the preparation of ceramic powders. Examples of the precipitants used include tetraalkylammonium hydroxides. A composition-modified barium titanate is one of the ceramic powders that can be produced. Certain metal-ion chelates can be prepared from 2-hydroxypropanoic acid and ammonium hydroxide.

Abstract: The invention relates to a process for the treatment and purification of dangerous wastes containing ammonium salts, particularly ammonium chloride, derived from pharmaceutical and chemical technologies. The process includes the following steps: removing the organic solvent content of the waste mixture, containing an aqueous and non-aqueous phase, by phase separation based on the difference in the special weight and/or by azeotrop distillation, and heating the obtained aqueous solution at its boiling point or at a temperature belonging to the maximal saturation boiling point of the ammonium salt until the non-solvent type organic substances precipitate in the form of a well separable polymerisate phase, whereafter this phase is separated from the aqueous solution of the ammonium salt and the ammonium salt, preferably the ammonium chloride is purified by a method known per se.

Abstract: An ammonia producing device for an exhaust system of an engine is provided. It includes a pressure vessel having a cavity for storage of pressurized gases. The pressure vessel includes insulation located at least partially about the cavity for limiting heat transfer from within the cavity. A flash heater is disposed within the cavity and adjacent a solid ammonia gas producing material. An outlet port extends from the pressure vessel and has a valve located therein for providing egress of pressurized gases from within the pressure vessel.

Abstract: The present invention provides phosphaplatins, stable isolated monomeric phosphato complexes of platinum (II) and (IV), and methods of use thereof for treating cancers, including cisplatin- and carboplatin-resistant cancers. Unlike cisplatin, these complexes do not readily undergo hydrolysis and are quite soluble and stable in aqueous solutions. Moreover, these complexes—unlike cisplatin, carboplatin, and related platinum-based anti-cancer agents—do not bind DNA. Rather, data suggests that phosphaplatins trigger overexpression of fas and fas-related transcription factors and some proapoptotic genes such as Bak and Bax. Nevertheless, the complexes exhibit tremendous cytotoxicity towards cancer cells. Thus, the present invention provides novel platinum anticancer agents that have a different molecular target than those in the art.

Abstract: The present invention is a process for the conversion of aluminum oxide hydroxide (AlOOH) to aluminum oxide. About 30 to 70 wt-% of AlOOH, about 30 to 70 wt-% ammonium hydrogencarbonate NH4HCO3 and 0 to 20 wt-% water are combined to produce a mixture. This mixture is then cured at a temperature from about 30° to about 90° C. to convert at least 5% of the AlOOH to a ammonium hydroxycarbonate (dawsonite-type) intermediate and then the dawsonite-type intermediate is decomposed at a temperature from about 130° to 320° C. to produce aluminum oxide. The aluminum oxide can be further calcined at 500° to 800° C. to produce a gamma-theta phase alumina.

Abstract: A process for producing ammonia and sulfuric acid from a stream comprising ammonium sulfate is provided. The process comprises the steps of heating the stream to produce ammonia and a decomposition product comprising one or more than one of a bisulfate salt, a pyrosulfate salt, or a combination thereof. The ammonia produced is recovered, and water is added to the decomposition product to produce a stream comprising the decomposition product. The stream comprising the decomposition product is processed by acid retardation to obtain a sulfuric acid stream and a stream comprising one or more than one sulfate salt.

Abstract: A method of producing NH2 (R2), the method comprising reacting a metal hydride with a compound having the general formula: M1x (BH4)y (NH2 (R2))n wherein M1 comprises one or more of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, La, Al, Ga and Sc; 0<n?4; R2 comprises —H, alkyl and an aromatic substituent; and x and y are selected so as to maintain electroneutrality.

Abstract: A stream of liquid methanol containing ammonia and other species is sent to the top of a countercurrent stripping column. The stream is stripped with a flow of ambient-temperature nitrogen or another inert gas. The column can be packed with random dumped packing. The overhead vapor contains ammonia and the liquid exiting the column has a reduced amount of ammonia. Removing ammonia can reduce or prevent fouling or corrosion caused by ammonia (and other compounds).

Abstract: Apparatus and method for generating ammonia gas. In one aspect, a method for generating ammonia gas for use in an ion mobility spectrometry (IMS) system is provided. The method includes inserting a device into a space defined within the IMS system, the device including an ammonia compound. The method also includes activating to decompose and to produce the ammonia gas without producing water vapor. The method also includes emitting the ammonia gas into the IMS system.

Abstract: A method for separating ammonia and sulfides from a sour water stream is disclosed. The stripping of a sour water stream where it is stripped to create a sour water stripper overhead gas and then contacted with an alkali hydroxide in order to separate ammonia and make an alkali sulfide.

Abstract: A safe, economical and predictable process for producing ammonia from a urea solution, preferably where only a small amount of ammonia is required, (i.e. for SCR denitrification for small boilers, flue gas conditioning to enhance precipitator efficiency and/or alleviate plume problems, SNCR and the like), using an ultrasonic processor to cause “cold boiling” of portions of such solution and produce gaseous ammonia.

Abstract: Taught is a method for removing ammonia nitrogen from an ammonia-containing solution via atomization, comprising a) adjusting the pH of the ammonia-containing solution to above 10 by adding a base; b) after mixing, atomizing the ammonia-containing solution to produce an ammonia-containing mist so as to increase the gas-liquid interface and allow ammonia to transfer from the ammonia-containing mist to an ambient gas yielding a clean mist; and c) re-aggregating said clean mist. The method is applicable for treatment of liquids containing high, medium and low ammonia nitrogen concentration.

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: There is disclosed a wet-processing method for combustion ashes of petroleum fuels, comprising a slurry preparation step of preparing a slurry of the combustion ashes; a metal oxidation step of preparing a slurry containing ammonium metavanadate; a solid/liquid separation step of removing solids from the slurry containing ammonium metavanadate; a double decomposition step for ammonium sulfate, of adding a magnesium compound to an aqueous ammonium sulfate solution recovered from the solid/liquid separation step; and an ammonia recovery step of recovering ammonia from a reaction solution recovered from the double decomposition step. The above metal oxidation step is conducted while controlling an ammonium sulfate concentration of the aqueous solution to 20 to 45% by weight and the temperature of the aqueous solution to not more than 50° C., and the above solid/liquid separation step is conducted using a specific solid/liquid separator while controlling the temperature of the slurry to not more than 40° C.

Abstract: Silazanes and/or polysilazanes are prepared by ammonolysis reaction in liquid anhydrous ammonia by introducing at least one halosilane into the ammonia. In addition to the silazane and/or polysilazane, an ammonolysis by-product also results. A substantially more efficient process is disclosed for treating the by-product through the addition of a liquid, namely water, or a solution comprising a strong base, or an aqueous acid solution. The process may be employed for more efficient, economical recovery of ammonia from such waste stream solutions of ammonia halide, or acids thereof for use as recycle in the further production of silazanes and polysilazanes, and/or for producing a less hazardous, more readily disposable salt residue thereof.

Abstract: A method for treating and upgrading effluents containing at least a metallic sulphate comprising adding at least a base to the effluent to precipitate the metallic ions in the form of iron oxy-hydroxides Fe(OHx) wherein x=2 and/or 3; separating the precipitated hydroxide calcium sulphate CaSO4; and separating the calcium sulphate CaSO4 precipitated during the preceding step. Said method enables obtainment of calcium sulphate (white gypsum) substantially free of metals and therefore capable of being upgraded and iron oxy-hydroxides likewise capable of being upgraded.

Abstract: A method is described for manufacturing ammonia and sulphuric acid by decomposition of ammonium sulphate by a chemical and thermal handling process The method concerns mixing of ammonium sulphate with concentrated sulphuric acid, where the mixture is heated to a temperature above 235° C., whereby ammonium sulphate is melted, and thereafter by heating the mixture to above 280° C. but below the boiling point of concentrated sulphuric acid. It is hereby achieved to decompose ammonium sulphate into ammonia gas and sulphuric acid liquid simultaneously, where the produced sulphuric acid during the reaction time is mixed ideally with the concentrated sulphuric acid from the initial basis mixture.

Abstract: An improved ion exchange process for manufacturing and concentrating hydroxylamine from an aqueous solution comprising hydroxylammonium ion and counter anions is disclosed. The process involves the use of an aqueous hydroxylamine wash step which assists in controlling the processing temperature and leads to a more concentrated, purified aqueous hydroxylamine solution.

Abstract: Denitrated combustion exhaust gas is desulfurized with ammonia, the waste water obtained from washing the desulfurization waste water or dust ash is filtered using calcium carbonate, the pH of the filtrate is adjusted, carbon dioxide and/or aqueous carbonic acid is added and then a flocculating agent is added, and ammonia is recovered from the supernatant after precipitation and separation of the solid portion. The recovered ammonia is added to the denitrated gas for treatment of the combustion exhaust gas.

Abstract: A method for removing ammonia from fly ash employs water mist (a water fog) or a flowing warm humid air stream to rid the fly ash of ammonia. Ozone alone or with other co-oxidants such as hydrogen peroxide are also used to rid fly ash of ammonia.

Abstract: Silazanes and/or polysilazanes are prepared by ammonolysis reaction in liquid anhydrous ammonia by introducing at least one halosilane into the ammonia. In addition to the silazane and/or polysilazane, an ammonolysis by-product also results. A substantially more efficient process is disclosed for treating the by-product through the addition of a liquid, namely water, or a solution comprising a strong base, or an aqueous acid solution. The process may be employed for more efficient, economical recovery of ammonia from such waste stream solutions of ammonia halide, or acids thereof for use as recycle in the further production of silazanes and polysilazanes, and/or for producing a less hazardous, more readily disposable salt residue thereof.

Abstract: The present invention relates to a pozzolanic admixture containing ammonia-laden fly ash, method for making the pozzolanic admixture and method for controlling ammonia gas (NH3) emission from cementitious slurries using the pozzolanic admixture. The associated hypochlorite and ammonia reaction produces monochloramine and chloride salts at relatively low concentration levels harmless to concrete and concrete applications. The resulting monochloramine and chloride salt products are stable and do not dissipate into the air, thereby, eliminating odorous emission that is produced from cementitious slurry containing untreated ammonia laden fly ash.

Abstract: A method for removing ammonia from fly ash employs water mist (a water fog) or a flowing warm humid air stream to rid the fly ash of ammonia. Ozone alone or with other co-oxidants such as hydrogen peroxide are also used to rid fly ash of ammonia.

Abstract: Methods for direct reduction of ammonia from waste streams by the steps of reacting an aqueous ammonia containing waste stream with a solution of a strong acid and a metal salt, wherein the cation in said metal salt of said solution is selected from the group consisting of Ag, Cd, Co, Cr, Cu, Hg, Ni, Pd, Zn; and wherein an ammonium-double salt is formed with said metal salt in an ammonia depleted waste stream; and treating said depleted waste stream to crystallize an ammonium-metal double salt therefrom.

Abstract: This invention provides a process for producing a free hydroxylamine aqueous solution, by letting an alkali react with separated sulfates, for conversion into ammonia and sulfates not containing any nitrogen atom, recovering the valuable ammonia and recycling it in the reaction system for effective use. This invention is a process for producing a free hydroxylamine aqueous solution, in which a free hydroxylamine aqueous solution is obtained by letting an aqueous solution or slurry containing hydroxylammonium sulfate and a gas mainly containing ammonia react with each other, mixing a solution mainly containing a lower alcohol with the produced aqueous solution or slurry, and separating the precipitated sulfates containing ammonium sulfate, comprising the steps of mixing an alkali with the separated sulfates, to produce ammonia gas, and recycling the ammonia in the reaction system.

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 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 abating acidic contaminants, such as sulfur dioxide and hydrogen chloride, in exhaust gases while minimizing the formation of visible plumes of ammonium salts proximate to the outlet of the exhaust stack by injecting a spray of an alkaline liquid, such as sodium hydroxide or potassium hydroxide, into the contaminated exhaust gases wherein the pH of the alkaline liquid is high enough, i.e. greater than a pH of about 11, so that the acidic contaminants preferentially react with the alkaline liquid rather than the ammonia in the gases, thereby minimizing formation of visible plumes of ammonium salts.

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 nitrile compound or an amide compound is hydrolyzed in the presence of an inorganic acid or other acidic catalyst or an alkali metal hydroxide or other basic catalyst, and the by-produced ammonium salt of the acidic catalyst or the produced salt of a carboxylic acid and a base is electrodialysed to form an acid and ammonia or aqueous ammonia, or to form a base and ammonia. The obtained acid or base may be recycled as a catalyst for the hydrolysis of the nitrile compound or amide compound, and the obtained ammonia is reutilized as a nitrogen source for the nitrile compound or amide compound. Such amide compound may be produced by hydration of a nitrite compound in the presence of a manganese oxide.

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 recovering valuables from a waste etching solution containing a fluorine component and ammonia component is provided comprising recovering respectively a fluorine component and ammonia component in the waste solution and recovering a potassium and/or sodium component used for processing the waste solution, and utilizing respectively the recovered components for preparation of an etching solution or reusing or recycling for processing the waste solution.