Abstract: Solid inorganic particulate salts having increased hardness are produced by incorporating a novel additive composition comprised of ammonium sulfate and a naphthalene sulfonate compound.

Abstract: A method for preparing ultra-pure silver from a crude silver mixture containing metallic and/or non-metallic impurities, said method comprising; dissolving the crude silver mixture in nitric acid to form a crude silver nitrate solution; adding a first selective reducing agent to the crude silver nitrate solution to precipitate a silver/contaminant matrix and form a partially purified silver nitrate solution; separating the partially purified silver nitrate solution from the precipitated silver/contaminant matrix; adding a second selective reducing agent to the partially purified silver nitrate solution to precipitate silver powder; and isolating the silver powder.

Abstract: A process for manufacturing ammonium salts using a reactor which includes a first tubular reaction chamber having at least one acid feed and at least on ammonia feed which are arranged in a first up-stream part of the reactor. At least one second ammonia feed is introduced into a second part of the reactor which is arranged as an extension of the first and which includes, in a flow direction, a convergent segment, a cylindrical tube and a divergent segment. The second ammonia feed communicates with the second part in the vicinity of the convergent segment and the processes is controlled to obtain basic vapors at an outlet of the reactor.

Abstract: According to this process, there is used a granulator (10) employing a rotary drum and a fluid bed which is usually employed for producing dense granules for the production of porous granules, For this purpose, the process comprises spraying in this granulator ammonium nitrate in solution and effecting a combined cycle of granulation and drying which causes the formation of pores in the mass of the granules. The drying is then terminated in a drier (20) and the product thereafter is screened and cooled.

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: An improved particulate, ammonium nitrate is prepared with 2.0-6.0 percent by weight potassium sulfate. The potassium sulfate suppresses crystalline phase IV.revreaction.III transitions in the ammonium nitrate particles while undergoing temperature variations between 18.degree.-42.degree. C. The resulting fertilizer, which may be further coated to further suppress dusting, exhibits superior resistance to caking, clumping and cracking.

Abstract: A porous prilled product, particularly ammonium nitrate, and its method of preparation, which includes encapsulated microspheres, particularly polymer microballoons, which serve to reduce the density of the product.The invention also extends to an explosives composition particularly ANFO and heavy ANFO, including such ammonium nitrate of reduced density.

Abstract: A combustion gas is cooled a first time to about 110.degree. C. in a first cooling chamber (3), up to 90% of the ashes is removed in a first precipitator (9) then the gas is cooled again in a second cooling chamber (10), to about 80.degree. C.; in a reaction chamber (13), by energization by means of electrons the sulphur dioxide and nitrogen oxides are converted into sulphuric acid and nitric acid and, with the addition of dry ammonia (15) the two said acids are converted to salts of ammonia, the latter are retained in a second precipitator (21) and sent to a chimney; characteristics of the method and the plant are that, from the instant of the injection of the ammonia into the reaction chamber (13), the temperature of the gas is maintained at above 80.degree. C.

Abstract: Exhaust gases containing oxides of nitrogen and sulfur from a fired process heater, a fossil fuel fired boiler, or a chemical process are diverted from a stack prior to admission to the atmosphere through a duct system containing heat exchangers that reduce the exhaust gas from an elevated temperature, if any, to about ambient temperature. Any heat extracted from the exhaust gas may be transferred to the boiler feed water which would serve to reduce the energy cost of operating a boiler. Once the exhaust gas is cooled to about ambient temperature, the gas is then mixed with an oxidant, such as ozone, at a preselected molar ratio to transform the oxides to higher orders of nitrogen and sulfur oxides to increase the absorbability of the nitrogen and sulfur oxides in a reagent solution. The reagent absorbs the oxidized contaminants from the exhaust gas. The oxides are transformed to dilute acids which are then neutralized to form salts that are acceptable for discharge to a municipal waste water treatment plant.

Abstract: Ammonium nitrate is phase-stabilized against Phase IV.rarw..fwdarw.Phase III transition and the undesired volume changes associated with that phase change by including an effective amount of at least one metal dinitramide salt having the formula MX.sub.n wherein M is a metal cation, X is a dinitramide anion, and n is 1, 2 or 3. The phase-stabilized ammonium nitrate is useful in energetic applications such as solid propellants and explosives.

Abstract: To make and use nitrogeneous fertilizer on a farm, nitrogen oxides are prepared in a continuous process from air or from ammonia in a reactor, with the ammonia either being transported to the farm or local site in a farming area or being prepared on the site in a continuous process from water and air. The nitrogen oxides are mixed with a continuous flow of water to form a solution of nitric acid, which may be applied to the field through the irrigation system as top dressing or mixed within the system with ammonium or other cations to form ammonium nitrate or other desired nitrogen solutions for application to the fields in a continuous process or concentrated without requiring storage of large amounts of gas or creating heat exchange problems in the manufacturing process.

Abstract: A process is provided for controlling the emission of nitrogen dioxide from, and the growth of living organisms in, steam condensate cooling towers and catch basins used in conjunction with a condensate of steam derived from an ammonia containing geothermal brine. The process comprises contacting the condensate, in a substantially continuous manner, with a less-than-stoichiometric amount of an oxidizing agent, which results in the oxidation of nitrite in the condensate to a nitrate. The process optionally provides for periodically introducing a biocide into the condensate in an amount which controls organism growth in the cooling tower and catch basin. To prevent system corrosion, the process may include treating the condensate with a non-organic, phosphate-based corrosion inhibitor and scale dispersant.

Abstract: A phase stabilized ammonium nitrate mixed crystal structure is produced by the addition of potassium fluoride. Thus the undesirable abrupt expansion and contraction of ammonium nitrate in the temperature range of use in rocket motor propellants and explosives (-55.degree. C. to .lambda..degree. C.) is eliminated. The mixture is made by the addition of between about 3% to 5% and preferably about 3.5% by weight potassium fluoride to the ammonium nitrate by a nonhazardous aqueous method.

Abstract: A phase-stable, oxidizer-grade zinc diammine complex stabilized ammonium nitrate that retains its phase-stability, has a minimum hygroscopicity and cure interference, is prepared by dissolving an anhydrous zinc diammine complex, which may be either the sulfate, perchlorate or nitrate, in dry molten ammonium nitrate. The complex is best prepared in a separate step by melting a 3/1 molar mixture of ammonium nitrate with zinc oxide which produces the zinc diammine dinitrate complex contaminated with the water of the reaction. The melt is dried by driving off the water. First by simple boiling, and the final traces by means of purging with dry air or nitrogen gas. The ammonia lost in this drying operation is exactly replenished by purging with anhydrous ammonia gas. The sulfate complex is obtained by co-dissolving an essentially stoichiometric quantity of ammonium sulfate in either the melt of the complex or the bulk of the molten ammonium nitrate.

Abstract: In a process for producing phase-stabilized ammonium nitrate (AN), a diammine complex of Ni or Cu is incorporated into the AN lattice, in which the diammine complex is produced in a solid-state reaction of AN and metal oxide at 110.degree. to 170.degree. C. and in a proportion of up to 10% is either mixed with further AN and melted, homogenized and subsequently transferred into the solid state, or mixed with further AN is incorporated into the AN lattice at between 80.degree. and 170.degree. C. in a solid-state reaction.

Abstract: Highly concentrated, aqueous colloidal dispersions of a cerium (IV) compound, adapted for the impregnation of catalyst supports, are prepared by reacting an aqueous solution of a cerium (IV) salt with a base, to precipitate a certain cerium hydroxynitrate, separating and washing said precipitate, and then dispersing the washed precipitate in an aqueous acid medium.

Abstract: Proton conductive material comprising a compound of a monoclinic crystal structure which is in a reversibly reduced state from a compound of a similar monoclinic crystal structure represented by the general formula:Na.sub.x Al.sub.y Ti.sup.3+.sub.x-y Ti.sup.4+.sub.8-x O.sub.16,in which 1.5.ltoreq.x.ltoreq.2, 1.5.ltoreq.y.ltoreq.2, x.gtoreq.y.The compund of a monoclinic crystal structure, represented by the general formula: Na.sub.x Al.sub.y Ti.sup.3+.sub.x-y Ti.sup.4+.sub.8-x O.sub.16 is changed reversibly to a compound of a monoclinic crystal structure in a reduced state by a reducing treatment at a temperature within a range from 600.degree..degree.C. to 1000.degree. C. Such a compound of a monoclinic crystal structure which is in a reduced state is changed reversibly back to the compound of a monoclinic crystal structure, represented by the general formula: Na.sub.x Al.sub.y Ti.sup.3+.sub.x-y Ti.sup.4+.sub.8-x O.sub.16 by applying heat treatment in air at a temperature within a range from 1200.degree. C.

Abstract: Process for producing concentrated solutions of ammonium nitrate by neutralization of nitric acid with ammonia in a pipe reactor.When the global flow of reactives corresponds to an output higher than 150 kg/h/cm.sup.2 neutralization is performed in the presence of recycled concentrated solutions of ammonium nitrate. When the global flow is higher than 150 kg/h/cm.sup.2 recycling is not necessary.

Abstract: A procedure for preparing anhydrous cerous nitrate ammonium nitrate complex comprising treating dried anhydrous ceric hexanitro ammonium complex (ceric ammonium nitrate) with a reducing agent such as ammonia whereby Ce.sup.+4 is reduced to Ce.sup.+3 under anhydrous conditions. The resulting Ce.sup.+3 species, a complex of Ce.sup.+3 nitrate and ammonia nitrate, can be used as a source of anhydrous Ce.sup.+3 ions.

Abstract: A process is provided for preparing concentrated aqueous solutions of byproduct nitrate compounds from dilute aqueous streams containing said byproduct nitrate compounds, calcium ions and anionic species capable of reaction therewith at elevated temperatures. The process provides for the removal of the calcium ions by the addition of a source of carbonate ions to said stream to form solid, particulated calcium carbonate therein, the separation of the solid particulate from the stream, the neutralization of the stream and concentration of the stream to provide a concentrated aqueous solution containing the byproduct nitrate compound.

Abstract: An aqueous liquid anticaking and antidusting composition is disclosed which comprises from 20 to 30 parts of a sodium naphthalene sulfonate, from 17 to 28 parts of an ammonium naphthalene sulfonate, and from 30 to 80 parts of water. In preferred practice, the compositions also include an alkene sulfonate containing from 6 to 26 carbon atoms as the sodium or potassium salt in an amount of from 1 to 5 parts. The compositions are neutralized with an acid, like sulfuric acid, to a pH of from about 5 to about 7.

Abstract: A process for the preparation of ammonium nitrate by the reaction of nitric acid with ammonia in two stages at elevated temperature, in which the first stage is carried out at elevated pressure and the second stage is carried out at atmospheric pressure. The heat of neutralization released in the first stage is used to vaporize a portion of the reactor contents, the remaining heat of reaction being utilized to produce steam. The vapor leaving the first stage develops a pressure which controls the valve regulating the amount of heat recovered by steam generation. The valve is opened when the pressure of the vapor exceeds a set value, usually in the range of 3.4 to 4.8 bars. Decomposition products of ammonium nitrate are also measured and override the pressure regulated control of the proporiton of heat recovered by steam generation, so as to maintain ammonium nitrate decomposition within acceptable limits. An apparatus for carrying out the process is also disclosed.

Abstract: This invention relates to a process and an apparatus for the production of ammonium nitrate which produce an ammonium nitrate solution of a sufficient concentration, preferably from 90 to 98% by weight using nitric acid solutions of a relatively low concentration. The ammonium nitrate solution is concentrated in a multistage evaporation installation in which at least one evaporator is heated by the steam generated by a depressurization of the ammonium nitrate solution.

Abstract: A method is provided for removing nitrogen oxides from waste gases, said method comprising the steps of oxidizing the nitrogen oxides in the waste gases by contacting the waste gases in a gas phase with an oxidizing agent to form NO.sub.2 ; absorbing the formed NO.sub.2 in an absorbing stage by contacting the oxidized waste gases with an absorbing agent to form an absorbing product while substituting fresh water for vaporized water in corresponding amounts; and processing the resultant absorbing product as a solution.

Abstract: The undesirable abrupt expansion and contraction of ammonium nitrate in the temperature range of use of a rocket motor and explosives (-55.degree. C. to 80.degree. C.) is eliminated by the addition of 0.5 to 2% by weight of a crystal growth inhibitor, specifically potassium fluoride (KF).

Abstract: A method of simultaneously removing SO.sub.x and NO.sub.x from waste gases. Using a known desulfurization process the waste gases free of the acidic components are contacted with an oxidizing agent in the gas phase for the oxidation of the oxygen of nitrogen contained in the waste gases. The formed NO.sub.2 is absorbed in a subsequent absorbing stage under previous addition of NH.sub.3 and the thereby obtained absorbing product is oxidized to form ammonium nitrate in a subsequent oxidation stage with atmospheric oxygen and then reconveyed into the desulfurization process.

Abstract: To make non-pressure nitrogenous fertilizer solutions, nitrogen oxides are prepared in a continuous process by burning ammonia in contact with a cobalt oxide catalyst started by an electric arc without preheating the gases. This burning forms nitrogen oxides which are reacted under negative pressure in a two-stage system. Nitric acid is formed in the first stage from a portion of the oxides by oxidizing them to nitrogen dioxide and reacting the nitrogen dioxide with water. In the second stage, the remaining nitrogen oxides are reacted at a pH between 8.0 and 8.4 in a gas-liquid contacting apparatus with an ammonium hydroxide reaction liquid, formed by mixing ammonia and water. The ammonium nitrite solution formed in the second stage is mixed with the nitric acid at a pH below 0.2, resulting in a solution of acidic ammonium nitrate to be flowed to the fields with irrigation water.

Abstract: The present invention relates to ammonium nitrate or products having a high content of ammonium nitrate stabilized against swelling and break-down by thermal cycling, and a method for manufacturing such products. An amount of 0.05-1.0 weight % porous particles having a surface area of 150-400 m.sup.2 /g and a pore size of 100-300 .ANG.ngstroms are included in the products. As porous particles, preferably silicon dioxide particles having a surface area of 250-350 m.sup.2 /g and a pore size of 100-250 .ANG.ngstroms are used. The products are made by first drying granulated or prilled ammonium nitrate or products having a high content of ammonium nitrate and thereupon coating them with the porous particles, and if desired also adding a dust-binding agent and/or an anticaking agent. Ammonium nitrate thus conditioned is both as stable and porous as required for use in explosives and in addition it meets the requirements for so-called tropical grade ammonium nitrate.

Abstract: A process for removing ammonium nitrate NH.sub.4 NO.sub.3 (AN) from an aqueous solution. At least one nitrogen-oxygen (N-O) compound in the form of NO.sub.x and/or N.sub.2 O.sub.2x, where x=1 or 2, is added to the aqueous solution containing the AN, the N-O compound being in gaseous or liquid state or as an ion present in an aqueous solution, at a temperature above room temperature but below the boiling point of the solution containing the AN and under normal pressure.

Abstract: Process for preparing magnesium nitrate hexahydrate without the need for filtering aids. A process for preparing magnesium nitrate hexahydrate essentially comprises: (a) forming a magnesium oxide or magnesium carbonate suspension in melted magnesium nitrate hexahydrate at a suspension temperature in excess of 90.degree. C.; (b) adding a nitric acid solution to the suspension while stirring thereby forming a reaction mixture containing additional magnesium nitrate hexahydrate; (c) filtering the liquid reaction mixture to obtain a clear magnesium nitrate hexahydrate filtrate; (d) discharging as product a part, corresponding to the amount of magnesium oxide or magnesium carbonate introduced, of the liquid magnesium nitrate hexahydrate obtained as clear filtrate; (e) utilizing the remaining part as liquid medium for the conversion of magnesium oxide or magnesium carbonate with nitric acid.

Abstract: Nitric oxide is prepared by the oxidation of ammonia produced by the Haber-Bosch synthesis technique by (a) vaporizing and heating water to superheated steam; (b) electrolyzing the superheated steam in a high temperature electrolysis cell to oxygen and hydrogen; (c) reacting said hydrogen with atmospheric nitrogen thereby forming ammonia by the Haber-Bosch process; and (d) oxidizing said ammonia to nitric oxide and water vapor in the anode of said electrolytic cell with the oxygen produced by said electrolysis.

Abstract: A process for preparing thermally stable ammonium nitrate-containing granules having high bulk density, high impact resistance, high crushing resistance, and little or no tendency to cake by spraying a liquid composition containing at most 15% by weight water, a stabilization agent, ammonium nitrate and other components into a fluidized bed of ammonium nitrate seed particles thereby forming granules and recovering the thus formed ammonium nitrate-containing granulated product.

Abstract: A process for preparing thermally stable ammonium nitrate-containing granules having high bulk density, high impact resistance, high crushing resistance and little or no tendency to cake by spraying a composition containing at most 5% by weight water, about 0.5% to 5% by weight of a insoluble and chemically inert silica-containing material, ammonium nitrate, and other components into a fluidized bed of ammonium nitrate seed particles thereby forming granules and recovering the thus formed ammonium nitrate-containing granulated product.

Abstract: Gas containing nitrogen oxides is treated in two separate stages. In the first stage, the nitrogen oxides in the gas are reacted with sulfurous acid. The gaseous product of this reaction is reacted with an alkaline solution, typically caustic alkali. As a result of these treatments, the nitrogen oxides are converted into neutral salts.

Abstract: A method of separating acids or bases from vapors which are conveyed along with distillation vapors during concentration of a solution, comprising, passing said distillation vapors containing an acid or base, while being maintained at their existing pressure and temperature, through a salt solution which boils at said temperature and pressure, wherein, if an acid is to be removed from the distillation vapors, the salt solution contains a salt having an anion corresponding to that of the acid while being supplied with a base in an amount required to neutralize the acid, the cation of the base proportion corresponding to that of the salt, while, if a base is to be removed from the distillation vapors, the salt solution contains a salt having a cation corresponding to that of the base while being supplied with an acid in an amount required to neutralize the base in the distillation vapors, the anion of the acid corresponding to that of the salt so that salts are formed during neutralization which correspond to t

Abstract: Roofing granules coated with insolubilized reaction product of a coating composition comprising water, kaolin clay, sodium silicate, titanium dioxide and ammonium nitrate or nitrate of one or more group 1A metals.

Abstract: A process is disclosed for the absorption of gaseous or liquid ammonia in acid solutions or slurries, including an ammonia absorption zone separated from a water vapor generation zone disposed at a higher level. A pressure difference is created between the two zones, so that the ammonia absorption takes place completely in the neighborhood of the point of inflow of the ammonia, with a temperature increase localized only near to said inflow point, and thus without giving rise to the generation of water vapor which therefore takes place in a liquid-vapor separation zone located at a higher level with respect to the ammonia absorption zone. The acid solutions or slurries to be neutralized may consist essentially of solutions of phosphoric acid, sulphuric acid, nitric acid, solutions resulting from the nitric acid attack on phosphorites, acid slurries resulting from nitric acid attack or sulphonitric acid attack on phosphorites, or mixtures thereof.

Abstract: Disclosed is a tracer fluid for use in connection with surfactant waterflooding or other chemicalized enhanced oil, recovery processes, and an oil recovery process using the fluid. Fluids containing easily identifiable components such as water-soluble, inorganic salts, specifically water-soluble nitrate salts, as well as low molecular weight alcohols may be used as tracer fluids for determining numerous flow and formation conditions between injection wells and production wells. Many of the most desirable tracers are degraded by bacteria present in field water or surface contamination. Incorporation of from 10 to 2000 and preferably from 50 to 1500 parts per million of an aromatic treating compound, preferably benzene, toluene, or xylene, stabilizes the chemical tracer against microbial attack.

Abstract: A method and apparatus for reconditioning waste solutions of the nuclear ustry which contain ammonium nitrate. The waste solution is continuously sprayed from above into a 300.degree. to 600.degree. C. hot zone, from the lower end of which the decomposition products are withdrawn and are separated into condensate and exhaust gas. The NO content is reduced by adding oxygen, especially at the exit of the decomposition zone. By the presence of reducing agents, such as CO(NH.sub.2).sub.2 or preferably NH.sub.3, in the solution to be sprayed, the NO.sub.2 content of the decomposition products and the NH.sub.4 NO.sub.3 residue in the condensate can be practically eliminated and an additional precipitation in the condensate which can be filtered off can be obtained. Optimal contents are 0.25-0.4 Mol NH.sub.3 and 0.15-0.25 Mol CO(NH.sub.2).sub.2 per Mol NH.sub.4 NO.sub.3.

Abstract: An improved process for the manufacture of ammonium nitrate prills and granules in which a water soluble aluminium salt is added to the process stream prior to the concentrate, which is then used in the prilling or granulating process, being formed.

Abstract: The invention relates to a process for the production of nitric acid with a concentration of 50-65% by weight by compression of a reaction gas and its absorption in water, said reaction gas originating from an ammonia combustion process, containing nitrogen oxides and being under pressure. The nitric acid produced by the process according to the invention is particularly suitable for further processing to fertilizer.

Abstract: A procedure is disclosed for preparing nitrogen-potassium fertilizer residing in interaction of potassium hydrogen sulfate with calcium nitrate, barium nitrate or strontium nitrate in an aqueous medium, followed by treatment of the reaction mass with ammonia, separation of the resulting slightly soluble sulfate and isolation of the desired product.

Abstract: Ammonium nitrite is commercially produced by contacting a gaseous stream containing nitric oxide, nitrogen dioxide, nitrogen and oxygen with an aqueous solution containing a basically reacting ammonium compound in an absorption system. However, at normal production rates, serious problems have been encountered because of relatively low yield of ammonium nitrite and the emission of unreacted nitric oxide which causes pollution of the atmosphere. It has now been found that in situ generation of nitrogen dioxide in the absorption system by operating the absorption system under slight pressure greatly improves ammonium nitrite yield, reduces nitrogen oxide emission, reduces loss of ammonia as nitrogen and minimizes mist formation in the vent gas.

Abstract: Disclosed are after-treatment processes and apparatus for synthesis plants, particularly urea and ammonium nitrate plants, but applicable also to various other plants in which the synthesis reaction does not go to substantial completion. In such plants product is fed to an evaporator for concentration and then to a solidification stage. The vaporous overhead stream from the evaporator contains entrained synthesis product, one or more unreacted starting materials, and solvent (usually H.sub.2 O). It is condensed, and the condensate is brought into mass and heat exchange relationship with the vaporous overhead stream from the evaporator substantially without material transfer of solvent to the condensate stream. The condensate stream is thereby enriched in synthesis product, heat is added to it, and unreacted starting material is desorbed from it. The product-enriched condensate is delivered to the solidification stage for processing there.

Abstract: In a process for removing particulate ammonium nitrate from the steam aerosol effluent from a reactor in which nitric acid is neutralized with ammonia, wherein said steam aerosol effluent is scrubbed with a water spray to produce suspended droplets of aqueous ammonium nitrate solution and said droplets are then removed from the effluent by passage through a fibrous mat, an improvement with respect to durability of the fibrous mat and efficiency of droplet removal is obtained by passing the effluent stream through a mat consisting of fibers of average diameter between 5 and 20 microns which have the following composition by weight: between 40 and 50 percent alumina, from 45 to 55 percent silica, less than 6 percent zirconia, less than 1.5 percent B.sub.2 O.sub.3 and less than one percent trace amounts of other inorganics.

Abstract: An improved process for preparing nitric acid. The process is characterized by the steps of (1) contacting gaseous nitrogen dioxide with feed water to yield aqueous liquid nitric acid and a gaseous by-product; (2) contacting the gaseous by-product with ammonia and water to yield a decontaminated gaseous effluent and an aqueous liquid by-product comprising aqueous ammonium nitrate, ammonium nitrite and nitric acid, and (3) feeding the liquid product to the first step above and reducing the amount of said feed water up to an amount equivalent to the water fed in the liquid product. The process is characterized by substantially reduced water consumption and improved pollution control economics and by the innocuous disposal of the hazardous ammonium nitrite.

Abstract: A gas stream containing nitrogen oxides, such as the tail gas from a nitric acid plant, is treated to reduce the nitrogen oxides content thereof. The method results in the production of an aqueous solution of ammonium nitrate. In a liquid-gas contact apparatus, the gas stream is first reacted, under steady state conditions, in counter-current flow, with an aqueous solution of ammonium nitrate at a pH of about 0.01 to about 0.5. The gas stream is then further reacted with an aqueous solution of ammonium nitrate at a pH of about 8.1 to about 8.5; and thereafter with water, preferably slightly acidified to a pH of 6.0 to 6.5. The resulting gas stream of reduced nitrogen oxides content may be safely discharged to the atmosphere without causing air pollution, the nitrogen oxides content being below imposed standards.

Abstract: An ammonium nitrate particle removal apparatus is joined with an exhaust gas flow of a nitrogen oxides abatement system as utilized in a nitric acid producing plant for removing ammonium nitrate particles carried in the gas flow. The apparatus includes a filter element for receiving the gas flow and substantially trapping the ammonium nitrate particles. Injection nozzles inhabit a conduit which delivers the exhaust gas flow to an inlet of the filter and inject a water mist into the gas flow which mist acts to irrigate the filter. As a result of this irrigation, the trapped ammonium nitrate particles go into solution and drop by the action of gravity to a tank or reservoir below the filter element, where the solution may be recovered for other uses as desired.

Abstract: A process and process plant for the manufacture of ammonium nitrate using urea process tail gas are provided. Water is reacted with nitrogen dioxide to form nitric acid, which is thereafter reacted with the urea process tail gas to yield an aqueous solution and a tail gas including carbon dioxide, ammonia and water vapor, A carrier gas is added to the tail gas, in order to control the amount of water vapor condensed out of the tail gas upon its being cooled to approximately 60 degrees C. Condensed water vapor is removed and passed to an absorption tower for use in the formation of the nitric acid, while the remainder of the cooled resultant stream is passed to the atmosphere.

Abstract: Processes for treating nitric effluents from plants so that a non-polluting stream is obtained and nitric values are recovered, which processes comprise acidifying nitric effluent, liquid-liquid extraction of the acidified effluent with an extraction agent comprising a neutral phosphoric ester and at least one long-chain alkylamine, and re-extraction of the loaded extraction agent with ammonia, thereby regenerating the extraction agent and providing ammonium nitrate, while at the same time providing a substantially nitric-free effluent.