Abstract: Carbonaceous materials are impregnated with bromine, chlorine, iodine or their compounds, and brought in contact with a flue gas in the presence of ammonia, whereby nitrogen oxides and sulfur oxides contained in the flue gas are trapped by the carbonaceous materials and can be removed from the flue gas with a very high percent removal.

Abstract: A method for purification of exhaust gases, which consists of a first purification process comprising making a liquid alkaline chemical react on the exhaust gas thereby to recover nitrogen oxides contained in said exhaust gas as a precipitate together with said liquid chemical and a second purification process comprising passing said exhaust gas which has undergone the first purification process through a glass-fiber mat thereby to convert said glass-fiber mat into an electrode, making the noxious components of the exhaust gas remaining after the first purification process adhere to said electrode and, at the same time, jetting a liquid chemical capable of generating oxygen subject to thermal cracking into the exhaust gas thereby to increase the oxygen content of the exhaust gas, and an apparatus suitable for use in practicing said method.

Abstract: An improved urea synthesis process is disclosed in which carbon dioxide and ammonia are reacted at 210.degree. to 245.degree.C under pressures of 250 to 600 atm., the gross molar NH.sub.3 /CO.sub.2 ratio in the liquid phase in the synthesis zone of the order of 2.5 and 8, the carbon dioxide and ammonia being reacted together in a synthesis zone then the resulting urea synthesis solution being stripped in a stripping zone which is in heat exchange relation with the synthesis zone through a wall, and the gas mixture resulting from the stripping is partially recycled to the synthesis zone.

Abstract: In a process for the production of urea from ammonia and carbon dioxide by feeding ammonia and carbon dioxide into a reactor, reacting the ammonia and carbon dioxide so as to produce an effluent aqueous solution of urea contaminated with ammonium carbamate, stripping the ammonium carbamate from the said solution in the presence of a stripping agent selected from ammonia and carbondioxide so as to produce an aqueous solution of urea substantially free from ammonium carbamate and a vapor phase of ammonia and carbon dioxide, and condensing ammonia and carbon dioxide to form a solution of carbamate for recycle into the reactor, and feeding ammonium carbamate to the reactor by entraining it in a stream of ammonia fed to the reactor through an ejector.

Abstract: A dense silicon carbide material having improved electrically conducting properties is disclosed which is prepared by forming a homogeneous dispersion of silicon carbide, a sufficient amount of boron nitride, and optionally a boron containing additive and hot pressing the dispersion at a sufficient temperature and pressure whereby a dense substantially nonporous ceramic is formed. The silicon carbide material can be machined by electrical discharge machining or by electrochemical machining.

Abstract: Contaminated wet-processed phosphoric acid is purified. To this end, the wet-processed phosphoric acid is mixed with one or more organic solvents, in which water is partially soluble, the organic solvent(s) is (are) separated from unabsorbed wet-processed phosphoric acid portions, and phosphoric acid is recovered from the organic solvent(s) so separated. The organic solvent(s) are more particularly used in the form of anhydrous material and at least in the quantity necessary to ensure dissolution (a) of the overall quantity of phosphoric acid contained in the wet-processed phosphoric acid and (b) of the free water therein.

Abstract: A workpiece made of a non-diamond carbonaceous material and having dimensions exceeding those of a polycrystalline diamond aggregate by a contraction coefficient value of the non-diamond material during its transformation into a polycrystalline diamond material, is enclosed with a powder-like catalyst having particle dimensions less than the minimum dimensions of the workpiece, subjected to a pressure of at least 80 kb, and heated by a pulse of electric current for a period of 0.1 to 10 seconds sufficient for the formation of said polycrystalline aggregate.

Abstract: Compositions are described including free-flowing particles of controlled size of purified metal halides such as sodium iodide and mixtures of sodium iodide with scandium iodide. These ultra-pure metal halide particles are particularly useful as a vaporizable fill disposed within an arc tube of a high pressure electric discharge device. The preparation and identification of the coordination entity Na.sup.+ScI.sub.4 .sup.- (III) is also described. The apparatus for producing purified metal halides of accurately controlled particle size includes means for evaporating volatiles from the solid impure metal halide, melting the impure halide, passing hydrogen, hydrogen halide, hydrogen and halogen, or mixtures thereof through the halide, and then passing the molten halide through a vibrating discharge conduit or nozzle into an inert quenching atmosphere to form the particles of purified halide.

Abstract: An improved ammonia synthesis train utilizing hydrocarbon starting materials which are converted to hydrogen under superatmospheric pressure in a series of steps which include conversion of the hydrocarbons to hydrogen-carbon monoxide mixtures, shift conversion of the carbon monoxide to hydrogen and CO.sub.2, and removal of the CO.sub.2. In such a system, reduction in process gas losses is achieved through an improved arrangement and integration of the shift conversion and CO.sub.2 removal steps. The carbon monoxide is first shifted in a series of shifts including a final low temperature shift; the bulk of the CO.sub.2 is removed by an essentially isothermal hot potassium carbonate CO.sub.2 removal system; the small residual amount of carbon monoxide is shifted to very low levels in a final low temperature shift; and the small amount of residual CO.sub.2 is then removed to very low levels in a second non-isothermal scrubbing system employing an aqueous solution of a chemical absorbent.

Abstract: A process suitable for recovering refractory metal carbide values from contaminated uncemented refractory metal carbides containing an iron group metal comprises heating an admixture of the powders of the contaminated refractory metal carbides and glacial acetic acid to the boiling point of the admixture for at least about 30 minutes, the weight of the powders divided by the weight of the acid is less than 5, thereafter removing the resulting carbide solids from the acid and washing the solids with sufficient water to remove the residual acid and drying the solids.

Abstract: In the production of acicular, ferromagnetic iron oxide of high coercive force by oxidizing an iron (II)-hydroxide suspension with an oxygen-containing gas to form acicular iron (III) oxide hydroxide and dehydrating the iron (III) oxide hydroxide, optionally tempering, reducing and/or reoxidizing this into magnetic iron oxide, the improvement which comprises effecting the oxidation of the iron (II)-hydroxide suspension at a pH of at least about 13, the suspension including SiO.sub.2 in the form of a sol or soluble salt, the resulting iron (III) oxide hydroxide having SiO.sub.2 deposited thereon.

Abstract: This disclosure teaches a method of making a silicon carbide article of less than full density. A mixture of silicon carbide particles, silicon particles and a thermosetting polymeric material are molded to form an article as a green body. The green body is pyrolyzed to change the polymer into carbon and the carbon is then changed into silicon carbide by the silicon contained in the mixture.

Abstract: A method for the production of a homogenous gas mixture from two gas streams of different parameters in which an open or free equalizing space downstream of a superimposed catalyst layer is provided. Within such open space is a mixing assembly imposing a little deflection upon the reaction gas stream causing a low pressure drop in the stream with a consequent reduced loss of energy. Quench gas is admitted through a two stage pressure reduction. It is first expanded from a duct surrounding the mixing assembly through a plurality of openings where the gas velocities are reduced and equalized. The second pressure reduction takes place across openings in the mixing assembly. Quench gas and reaction gas are then thoroughly mixed in the mixing assembly and the gas mixture is consequently passed to the entrance of a second catalyst layer downstream.

Abstract: Sulfur dioxide and ammonia remaining in waste-gas after partial purification thereof, for example by means of ammonia or ammonium sulfite solutions, are withdrawn from said gas by washing with a diluted aqueous solution of ammonium sulfate; the resulting ammonium sulfite containing solution is oxidized thereafter either by means of air or in an electrochemical cell.

Abstract: A process is provided whereby dilute aqueous phosphatic acid solutions of 2 to 3 percent or less and containing generally less than 1 percent fluorine are substantially quantitatively defluorinated without loss of the phosphorous or acid values of the water and with a net production of H+ ions from the contained SiF.sub.6.sup.= ions.

Abstract: Internal water balance within a liquid carbamate recycle urea process is controlled. Pressure in decomposer and/or condenser system can be varied to effect control. Also, refractive index of carbamate recycle solution can be determined and related to water balance.

Abstract: Urea is produced by reacting phosgene and ammonia, one of the reactants being in the liquid state and the other gaseous, at -50.degree. to -20.degree.C.

Abstract: A recycle loop method and recuperative heating system is provided for thermally recombining hydrogen and oxygen, such as may be desired in connection with a dissociated gas stream from a containment vessel for a nuclear reactor under loss of coolant accident conditions. The dissociated charge stream is preferably heated by indirect heat exchange with a resulting water vapor containing combined stream to effect heat conservation and, also preferably, the recuperative heat exchange operation and the high temperature recombining reaction are carried out in a unitary zone incorporating electrical, non-flame, heat input means.

Abstract: Hydrotreating of normally liquid hydrocarbon feeds has long been practiced to convert organic sulfur compounds to hydrogen sulfide for subsequent removal by adsorption. It has now been found that hydrotreating of said feed stocks over a nickel molybdenum oxide or cobalt molybdenum oxide catalyst also converts trace quantities of organic chloride compound to HCl which not only is a poison for catalysts in subsequent reactions but seriously reduces the sulfur retention capacity of zinc oxide sulfur adsorbents. A solid chloride adsorbent having a chloride retention capacity some twentyfold greater than known adsorbents has been developed for the sequential removal of hydrogen chloride contaminants in trace quantities to a level of less than one part per million in hydrogen treated streams. This adsorbent serves as a guard for catalysts in subsequent catalytic processes as well as a guard for the solid sulfur adsorbent utilized immediately downstream therefrom.

Abstract: In a process for the removal of hydrogen cyanide from raw gases containing at least one other acidic component selected from the group consisting of hydrogen sulfide, carbonyl sulfide and mixtures thereof comprising scrubbing said other components from the gases with a scrubbing agent, regenerating resultant loaded scrubbing agent, and recycling resultant regenerated scrubbing agent to the scrubbing step,The improvement wherein the hydrogen cyanide is scrubbed out simultaneously with the other acidic components, resultant loaded scrubbing agent is mixed with an aqueous alkali metal or alkaline earth hydroxide solution, and the thus-formed cyanide salt solution is thermally converted into ammonia and formate.