Abstract: A catalyst for the ammoxidation of propylene to prepare acrylonitrile with a high yield thereof comprising an oxide composition of the empirical formula (I)Mo.sub.a Co.sub.b Ni.sub.c Fe.sub.d Bi.sub.e V.sub.f Ca.sub.g K.sub.h X.sub.i Si.sub.j O.sub.k (I)wherein X is zirconium and/or chromium, the subscripts a, b, c, d, e, f, g, h, i and j respectively denote the number of the respective atoms of the elements, when a=10, b=0 to 8, c=0 to 8, (b+c)=2 to 10, d=0.3 to 7, e=0.01 to 3, f=0.01 to 2, g=0.01 to 5, h=0.05 to 0.5, i=0 to 2, j=10 to 50, and the subscript k denotes the number of oxygen atoms which satisfies the average valency of the elements other than oxygen and the ratio a:k being in a range of 10:30 to 80, which catalyst is prepared by preparing an aqueous slurry containing respective element-containing compounds, by spray drying the aqueous slurry to prepare a dried solid precursory catalyst and, finally, by calcining the precursory catalyst as a temperature of from 500.degree. to 750.degree. C.

Abstract: The known hydrocyanic acid-methane-ammonia (BMA) process for the production of hydrogen cyanide can now be carried out with liquified gases namely through the presence of additional hydrogen at the beginning of the reaction. The atomic ratio of carbon to nitrogen and hydrogen is from 1:1:7.1 to 1:1.33:13. As additional hydrogen there is the portion of hydrogen present coming out of the reaction "hydrocarbon+NH.sub.3 ". Otherwise the reaction conditions are the same as in the known BMA process.

Abstract: This specification describes a process and a catalyst for the removal of a gaseous carbon compound pollutant in the form of a gas containing the same by oxidation. The gas is passed through a catalyst bed in which the catalyst comprises a porous refractory support having a platinum group metal deposited thereon, said oxidation involving bringing said gas to its ignition temperature followed by combustion of said gas in the presence of said catalyst. In the process of the invention, the ignition temperature of the said gas is lowered to a temperature below 350.degree. C.

Abstract: A process of treating an exhaust gas containing NO.sub.x and SO.sub.2 comprising bringing the gas into contact with an absorbing solution containing iron chelate salt and potassium sulfite, cooling the solution to crystallize and separate absorption products of potassium imidodisulfonate, potassium dithionate and potassium sulfate, heating the separated products at 250.degree. to 400.degree. C. to decompose the potassium dithionate into potassium sulfate and sulfur dioxide, then decomposing the potassium imidodisulfonate into ammonia and simultaneously reducing the potassium sulfate into potassium polysulfide and potassium carbonate, and converting the potassium polysulfide into hydrogen sulfide, gaseous sulfur and potassium carbonate.

Abstract: When exhaust gas from a coal-burning boiler containing NO.sub.x as well as SO.sub.x is subjected to NO.sub.x removal by catalytic reduction of the NO.sub.x with ammonia and the coal ashes contained in the gas are separated, the coal ashes are contaminated by a certain quantity of ammonium compounds produced from the SO.sub.x and the ammonia excessively used. The ammonium compounds in the coal ashes are decomposed into ammonia and a sulfur compound by heating by the hot gas at a temperature in the restricted range, viz. 350.degree. to 700.degree. C., thereby to release ammonia into the gas preferentially to the sulfur compound. The ammonia thus released is recycled to the NO.sub.x removal step.

Abstract: A process for producing cubic system boron nitride comprises contacting calcium or strontium boron nitride with hexagonal system boron nitride and heating at higher than 1,450.degree. C. under the thermodynamically stable pressure for cubic system boron nitride.

Abstract: The invention relates to a process for the production of nitric oxides, which can be used for the production of nitric acid and for the production of fertilizers based on these, which process for the production of nitric oxides comprises establishing an electrical discharge, passing through the discharge a mixture comprising air and nitric oxide as seeding material, and recovering the produced nitric oxides. The invention further relates to a mobile and easily transportable system for effecting such process, which comprises at least one discharge device, means for supplying air to said discharge, means for supplying electricity and means for introducing nitric oxide as seeding material into the discharge zone.

Abstract: A method for the separation of nitric acid from a mixture of nitric acid with one or more of phosphoric, sulphuric or hydrochloric acids, in which the nitric acid is selectively extracted from a first phase comprising the acid mixture into a second phase by an amine nitrate. The method may conveniently be carried into effect by treating an aqueous mixture of acids with kerosene containing tri-n-octylamine nitrate and a modifyier e.g. decanol following which the excess nitric acid is stripped from the kerosene phase by water or dilute nitric acid.

Abstract: A boron nitride bonded boron nitride fiber article and the method for its manufacture which comprises forming a shaped article with a composition comprising a bonding compound selected from boron oxide and boric acid and a structural fiber selected from the group consisting of boron oxide, boron nitride and partially nitrided boron oxide fibers, heating the composition in an anhydrous gas to a temperature above the melting point of the compound and nitriding the resulting article in ammonia gas.

Abstract: In a process for desulphurizing gases containing SO.sub.2 and SO.sub.3 by absorption of the sulphur containing compounds by means of absorbents based on alumina free of alkaline substances, activated alumina or alumina carrying salts or oxides of at least one element selected from the groups IB, IIB, IVB, VB, VIB, VIIB, VIII of the Periodic Classification, the absorption takes place at temperatures comprised between 100.degree. and 400.degree. C., and the absorbent loaded with said compounds in the form of sulphates is heated with a gas containing a reducing gas, especially H.sub.2 S, to a temperature of 250.degree. C. to 450.degree. C., while the elementary sulphur thus formed is separated from said absorbent, whereafter the latter is re-used in a subsequent absorption operation.

Abstract: A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a substantially quinone-free aqueous washing solution containing, inter alia, solubilized vanadium, thiocyanate ions, and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the washing solution, is separated from the regenerated solution.

Abstract: Submicron 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, 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, 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 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: A process is provided for producing elemental sulphur from a hydrogen sulphide and sulphur dioxide containing gas stream by a Claus type of catalytic reaction. The process is based on the discovery that the conventional Claus catalyst, in the presence of liquid sulphur and at pressures considerably greater than one atmosphere, is significantly active toward the Claus catalytic reaction. Thus, in accordance with the invention, increasing the pressure of the reaction in the presence of liquid sulphur increases both the catalytic activity and the elemental sulphur conversion. The process involves introducing a compressed hydrogen sulphide and sulphur dioxide containing gas stream into a catalytic reactor and reacting the gases in a Claus catalyst bed in the reactor to produce elemental sulphur under conditions of temperature and pressure such that water in the reactor exists only as water vapor and sulphur vapor is condensed in the catalyst bed, being removed therefrom as a liquid.

Abstract: Carbon monoxide is selectively removed from a gas stream by a process which comprises contacting the gas stream with an absorbent solution containing the reaction product of a Cu(I) compound and a halogenated acetylacetone of the formula: ##STR1## where X is a halogen, R.sub.1 is CX.sub.3, linear or branched C.sub.1 to C.sub.8 alkyl, C.sub.4 to C.sub.6 heterocycle containing O, S or N or C.sub.6 to C.sub.10 aryl, R.sub.2 is hydrogen or C.sub.1 to C.sub.6 alkyl, or R.sub.1 and R.sub.2 are joined together to form a C.sub.6 ring.

Abstract: Organic reaction mixtures, particularly of mixtures containing contaminant organic phosphorus compounds and/or sulfur, are worked up by introducing the mixture into water which has been made alkaline and has a temperature of from -10.degree. to +50.degree. C., a pH value of at least 10 being maintained in the resulting mixture, separating the aqueous phase from the sulfur which separates out; and contacting the aqueous phase or the sulfur which has separated out with nitric acid at an elevated temperature and a pH of below 3.

Abstract: A process for the manufacture of nitric acid comprises contacting a mixture of starting gas, containing oxygen, nitrogen oxides and, possibly water, this mixture being previously cooled, oxidized and, optionally dried, with cooled nitric acid aqueous solution to provide a solution of nitrogen oxides in nitric acid aqueous solution, consisting fundamentally in that the said solution is reacted according to the reaction:2 NO.sub.2 (and/or N.sub.2 O.sub.4)+1/2 O.sub.2 +H.sub.2 O.fwdarw.2 HNO.sub.3with the air previously contacted with the solution of nitrogen oxides in the highly concentrated nitric acid resulting from the said reaction, so as to rid the said highly concentrated acid of the nitrogen oxides dissolved therein.

Abstract: An improved process for nitrite production is based on controlled oxidation of nitric oxide in a mixture of nitrogen oxides and oxygen. Oxidized gas is absorbed into an aqueous solution containing a basically reacting ammonium or alkali metal compound to produce nitrite and unabsorbed exit gas. The mole ratio of nitric oxide (NO) to nitrogen dioxide (NO.sub.2) in the unabsorbed exit gas is maintained within a range between 0.8 and 1.2 by either recycling a selected fraction of oxidized gas through the oxidizer or by selectively splitting the inlet stream to the oxidizer. Increased product yield as well as reduced NO.sub.x emissions are achieved as a result.

Abstract: A method for treating a nitrogen oxide- and sulphur oxide-containing waste gas, in which gaseous ammonia is mixed with said waste gas, the resulting mixed gas is passed in the cross current direction through a first reactor provided with a moving bed of carbonaceous catalyst particles adapted to move downwards, the gas having passed through the upper part of said reaction is discharged outside of the reactor without undergoing treatment, the gas having passed through the lower part of the reactor is mixed with a fresh gaseous ammonia, and this mixed gas is passed in the cross current direction through a second reactor provided with a moving bed of carbonaceous catalyst particles adapted to move downwards and then discharged outside of the reactor.

Abstract: A procedure for the treatment of filter cakes obtained during the purification of chemical substances in liquid form, especially during the purification of phosphoric acid obtained by wet methods, whereby a filter cake is dried and heated in the presence of a melt of inorganic material.

Abstract: A lightweight insulative, structural concrete is produced from a cement mix containing lightweight aggregates having precisely defined physical and chemical properties. These aggregates are very low in density and very high in amorphous SiO.sub.2 content. The concrete product produced using the mix of this invention has a unique combination of high structural strength (up to 3400 psi, 28-day compressive), low density (50 to 110 pounds per cubic foot) and high thermal resistance (R) values (up to 3.16/inch). Such a product is just as strong, one half the weight, and 36 times more insulative than ordinary hard rock concrete.