Abstract: A process for the reductive removal of a nitrogen oxide from a gaseous stream, particularly a stream containing oxygen, water, sulfur dioxide, nitrogen oxide and nitrogen, by contacting the stream with ammonia in the presence of a mixture of two catalysts. The first catalyst comprises copper or a copper compound, preferably copper sulfate supported on a porous carrier material. The second catalyst is a combination of metals or compounds thereof, preferably sulfates of vanadium and iron or tungsten and iron, also dispersed on a porous carrier material.

Abstract: Compounds containing sulphur-nitrogen groups, such as S.sub.4 N.sub.4, S.sub.5 N.sub.5.sup.+ salts and poly(sulphur nitride), are made by reducing S.sub.4 N.sub.3 Cl or related compounds with anions (e.g. iodide) or metals (e.g. silver). Poly(sulphur nitride) may be made by passing S.sub.4 N.sub.3 Cl vapor or S.sub.5 N.sub.5 FeCl.sub.4 vapor through sulphidized silver wool and condensing the vapor.

Abstract: Submicron carbon-containing titanium diboride powder and other hard, refractory metal boride powders, such as zirconium diboride and hafnium diboride powders, are prepared by vapor phase reaction of the corresponding metal halide, e.g., titanium halide, vaporous carbon source, and boron source reactants in the presence of hydrogen in a reaction zone and in the substantial absence of oxygen, either combined or elemental. In a preferred embodiment, the metal halide, e.g., titanium tetrachloride, carbon source, e.g., halogenated hydrocarbon, and boron source, e.g., boron trichloride, reactants are mixed with a hot stream of hydrogen produced by heating hydrogen in a plasma heater. The reaction zone is maintained at metal boride forming temperatures and submicron solid, carbon-containing metal boride powder is removed promptly from the reactor and permitted to cool. The preponderant number of metal boride particles comprising the powder product have a particle size in the range of between 0.05 and 0.7 microns.

Abstract: Hot discharged products of combustion from internal combustion particularly diesel engines containing oxidizable hydrocarbons, carbon monoxide, and particulate carbon are commingled with an inert halogenated hydrocarbon liquid, having eight or more carbon atoms in its make up; absorbing and entrapping these contaminants therein. The inert absorber liquid, pregnant with the contaminants, is then pressurized, which along with the temperature rise of the absorber liquid created from exchange of heat from the products of combustion gases, along with dissolved excess oxygen available from the excess air used during combustion: Wet oxidizes in a very short time the hydrocarbons, carbon monoxide, and particulate carbon to non objectionable carbon dioxide and water vapor; which are then disposed of to atmosphere. This invention is the process wherein these functions take place.

Abstract: A fibre-reinforced cementitious product comprising a fibre reinforcement, at least partly consisting of eucalyptus fibres.

Abstract: Process for the work-up of hydrogen-sulfide containing gases which are normally subjected to Claus process, reduction, absorption, and desorption, characterized in that a portion of the feed gases by-passes the Claus unit and is processed in a CO.sub.2 -selective secondary absorption-desorption procedure.

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: In a process for eliminating impurities and undesirable components from gas mixtures by passing the mixture through an activated carbon-containing adsorber. Sulfur compounds including hydrogen sulfide are eliminated by increasing the oxygen contents of the gas mixture which contains at least oxygen and/or sulfur dioxide in addition to the hydrogen sulfide to an extent that a hydrogen sulfide oxygen molar ratio is obtained in the gas mixture which is between about 1:0.45 and 1:0.65. The process may also be carried out with two groups of adsorbers where in the first adsorber the elemental sulfur is eliminated in liquid form and where the remaining minor portion of sulfur in vaporous or mist-like form is then removed in the second group of adsorber or adsorbers by adsorption on the activated coal. The purified gas is then recovered from the adsorber or with two groups of adsorbers from the second group of adsorber or adsorbers and the activated carbon is subjected to periodic regeneration cycles.

Abstract: A method of abating nitrogen oxides in waste gases resulting from a combustion process comprises the steps of introducing the nitrogen oxides-(NOx-)containing waste gases into an enclosed furnace body having surrounding wall, at an opening of a reduced cross sectional area formed in the bottom of the furnace body, while feeding fuel and ground raw material into the furnace portion above the gas inlet opening, thus forming a jet zone, producing a reducing atmosphere in the jet zone as a result of incomplete combustion of the fuel caused by insufficient supply of air (or oxygen) for the combustion, and then bringing into mutual contact and mixing the combustion waste gases and thermal decomposition of the material, and thereby reducing the NOx in the combustion waste gases through the catalytic action of the thermal decomposition products, and an apparatus for practicing the method.

Abstract: A process for the manufacture of ammonium sulfamate by introducing under pressure ammonia and sulfur trioxide into a reactor containing a melt which mainly consists of ammonium sulfamate and ammonium imidodisulfonate, while maintaining a molar ratio of NH.sub.3 /SO.sub.3 of from 1.5 to 1 to 2.0:1, which comprises introducing sulfur trioxide into the gas phase above the melt.

Abstract: German published patent application 2,710,399 discloses a process for the manufacture of ammonium sulfamate involving introducing sulfur trioxide and ammonia into a pressure vessel containing a melt that mainly consists of ammonium sulfamate and ammonium imidosulfamate, while maintaining a molar ratio between NH.sub.3 and SO.sub.3 from 1.5:1 to 1.99:1. It has now been found that the pressure vessel is suitably released from pressure for a short period of time after prolonged reaction times to discharge thus the main quantity of the collecting inert gases.

Abstract: Ammonia gas is scrubbed from a gas stream in a bed of material soaked with acid, and the bed is regenerated by passing an oxygen containing gas therethrough. The preferred acid is phosphoric acid and the preferred support material is carbon in the form of porous particles. In a fuel cell system dual scrubbers alternately scrub ammonia from reform gas and are subsequently regenerated so as to provide the fuel cells with a continuous flow of substantially ammonia free hydrogen.

Abstract: A novel high strength, high heat resistance sintered body suitable for use as refractory and abrasive materials is proposed. The sintered body comprises from 99.99 to 70% by weight of a combination of at least two kinds of metal diborides selected from the group consisting of diborides of Ti, Ta, Cr, Mn, Mo, Y, V, Hf, Nb, Al and Zr and from 0.01 to 30% by weight of a metal boride or borides selected from the group consisting of borides of nickel, iron and cobalt.The sintered body of the invention can be prepared by sintering the powdery mixture of the components at a relatively low temperature of 1800.degree. C. or lower and has a bending strength as high as 190 kg/mm.sup.2 and a Vickers hardness of 3300 kg/mm.sup.2 at room temperature and 2400 kg/mm.sup.2 at 1000.degree. C.

Abstract: The present invention provides a method of treating a waste anesthetic gas by contacting the laughing gas contained in the waste anesthetic gas with a catalyst comprising one or more metal oxides selected from the group consisting of ferric oxide, cobalt oxide, cupric oxide, chromium oxide, manganese dioxide and nickel oxide to decompose the laughing gas into nitrogen and oxygen. This method is of practical value for preventing the neighborhood of hospitals from environmental pollution problem.

Abstract: There is described a process for preparing large crystals of basic aluminum nitrate (BAN) from a nitric acid feed solution containing Al.sub.2 O.sub.3 values comprising the steps of:(1) evaporating water and nitric acid from the solution in a single step evaporation performed at a temperature of between about 270.degree. and about 450.degree. F. and at a pressure of between about atmospheric and about 60 psig to produce an evaporated liquor comprising at least about 16% alumina by weight;(2) holding the evaporated liquor in a quiescent state for a period of between about 20 minutes and about two hours within the temperature range of about 270.degree. F. to about 340.degree. F.;(3) injecting water into the product of step 2, the water being added in an amount sufficient to adjust the composition of the conditioned liquor to a composition expressible as the sum of two components(1) ANN (Al.sub.2 O.sub.3.6HNO.sub.3.15H.sub.2 O or Al(NO.sub.3).sub.3.9H.sub.

Abstract: This invention relates to catalysts and more particularly to the catalyst decomposition of one or more oxides of nitrogen present in a gas stream by contacting the gas with a catalyst comprising a compound of the formula A.sub.x B.sub.y, where A is selected from the group consisting of Tl, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Th, and U, B is selected from the group consisting of B, C, N and Si, x has a value 1.ltoreq.x.ltoreq.7 and y has a value 1.ltoreq.y.ltoreq.4.

Abstract: A method of treating an exhaust gas at a high temperature containing nitrogen oxides and sulfur oxides by bringing the exhaust gas into contact with an absorbing solution containing at least an iron chelate salt and potassium sulfite to thereby convert said nitrogen oxides and sulfur oxides into a mixture of potassium imidodisulfonate, potassium dithionate and potassium sulfate, characterized in that (1) the exhaust gas at a high temperature is cooled to a temperature below 80.degree. C. before bringing it into contact with the absorbing solution, (2) the concentration of potassium sulfite as the sulfite component in the absorbing solution is kept at least at 0.8 mol/kg, and (3) the mixture of salts produced in the absorbing solution is crystallized by cooling and separated by filtering the absorbing solution.

Abstract: This invention relates to a process for catalytic oxidation of oxides of sulfur and also relates to oxidation of oxides of sulfur oxides and oxides of nitrogen.

Abstract: Sulfur dioxide in the stack gas from an industrial process is converted to elemental sulfur in a Claus reactor at low temperature to produce sulfur fume. The sulfur is condensed by direct heat transfer with a continuously flowing countercurrent recirculating catalyst and a substantially sulfur dioxide-free gas is discharged. Catalyst and condensed sulfur are fed into the top of a sulfur recovery column and heated in the top of the column by direct heat transfer with a countercurrent stream of recycle gas. The sulfur and catalyst descend into a vaporization zone of the column where sulfur is vaporized. The vaporized sulfur is carried by the recycle gas back towards the top of the column and condensed to a fume by incoming sulfur bearing catalyst. The sulfur fume is carried from the top of the column in cold recycle gas. Hot catalyst from the vaporization section of the column is cooled by recycle gas entering the bottom of the column. Sulfur fume is recovered conventionally.

Abstract: A method for the regeneration of spent pickling acids. Said acid is mixed with such a minor quantity of a stronger acid that the losses of said stronger acid are compensated. The mixture obtained is stripped, whereby the weaker acids are vaporized. The vapor phase containing the weaker acids is passed to a condenser. The condensate obtained forms the regenerated pickling acid. The spent pickling acid can also be passed directly to an evaporator in which a solution containing a stronger acid is circulated. The vapor from the evaporator is passed to an absorption column and thereafter to a condenser, the regenerated acid being formed of the condensate from said condenser.