Abstract: A side-stream portion of a Stretford Process solution is taken from the main-stream in order to reduce the amount of deleterious side-products in the solution and the ADA values and vanadium values are salvaged from the side-stream by taking up the ADA values on activated charcoal and the vanadium values in an anion exchange resin. The ADA and vanadium values are recovered for re-cycling back to the Stretford Process.

Abstract: There is disclosed a process for preparing ultra pure silicon from metallurgical grade silicon, which comprises (a) continuously passing powdered and acid-leached metallurgical grade silicon through an induction plasma; (b) quenching said treated particles whereby upon solidification of the molten particles, a portion of the impurities therein migrates to the surface of the granules obtained; (c) acid-leaching the surface impurities of the granules obtained in step (b); and (d) after drying the granules obtained, repeating steps (a), (b) and (c) until a silicon of the desired purity is obtained.

Abstract: The present invention relates to a process for the manufacture of potassium nitrate from potassium chloride and nitric acid. According to the invention, potassium chloride and nitric acid are reacted in an aqueous medium at a temperature in the range of between -25.degree. C. to +10.degree. C. From the brine solution obtained after the separation of the resulting potassium nitrate, nitric acid is extracted by an organic solvent solution containing at least one compound selected from the group consisting of ketones having five to ten carbon atoms, straight or cyclic polyethers having molecular weight in the range of 100 to 1000, polyalkylene glycols slightly miscible in water and having molecular weight in the range of 1000 to 3000, and organic esters of phosphoric acid, phosphonic acid and phosphinic acid, or mixtures thereof, in an organic diluent which does not substantially extract hydrochloric acid. The remaining aqueous solution consists of a substantially nitrate-free brine containing hydrochloric acid.

Abstract: A rhodium catalyst containing supported rhodium metal omnipresent in the surface layer or in the neighborhood of the surface layer of the particles of a silica or titania type support is presented. This catalyst is prepared by a method (i) in which the support is dipped into an aqueous solution of a water-soluble rhodium salt previously adjusted to a pH of at least 10, followed by the drying and reduction, or a method (ii) in which the support is first dipped into an aqueous solution of a water-soluble rhodium salt having a pH of 1 or less and, then, dipped into an aqueous alkaline solution containing an alkaline compound in an amount sufficient to neutralize the acid impregnated in the support and also sufficient to convert the rhodium salt impregnated in the support into rhodium hydroxide, followed by the drying and reduction.

Abstract: The present invention relates to lining units used to protect surfaces exposed to intensive wear by solids, gases and liquids.The lining unit is a metallic shell formed with a pipe of rectangular cross section, containing a metallic plate and a wear-resistant composite material, the shell, the metallic plate and the composite material being diffusion-joined one to another.

Abstract: Nitrous oxide having a high purity is produced by reacting urea, nitric acid and sulfuric acid at a temperature of 40.degree. through 100.degree. C., and isolating the resultant nitrous oxide from the reaction gas mixture, without any danger of, for example, explosion during the reaction and without using expensive catalysts and sulfamic acid.

Abstract: A multi-stage process for reducing the content of sulfur-containing gases--notably hydrogen sulfide, sulfur dioxide, carbonyl sulfide and carbon disulfide--in waste gas streams is provided. In the first stage, the gas stream is passed through a reaction zone at a temperature between about 150.degree. and 350.degree. C. in the presence of a pretreated novel catalyst of the formulaxLn.sub.2 O.sub.3.yT.sub.2 O.sub.3in which Ln is yttrium or a rare earth element and T is cobalt, iron or nickel, and each of x and y is independently a number from 0 to 3, said catalyst being substantially non-crystalline and having a surface area of from about 10 m.sup.2 /g to about 40 m.sup.2 /g. The preferred catalyst is one in which Ln is lanthanum, T is cobalt, and x and y range from 1 to 3, including non-integers. The first stage yields a product stream having a reduced content of sulfur-containing gases, including specifically, substantial reduction of carbonyl sulfide and virtual elimination of carbon disulfide.

Abstract: In an apparatus for refining molten metal comprising, in combination:(a) a vessel having an inlet zone and an outlet zone; at least two refining compartments in between, connected in series, separated by baffles, and positioned in such a manner that the first refining compartment in the series is adjacent and connected to the inlet zone and the last refining compartment in the series is adjacent and connected to the outlet zone; and dross removal means; and(b) one rotating gas distributing device disposed at about the center of each refining compartment, said device comprising a shaft having drive means at its upper end and a rotor fixedly attached to its lower end, the upper end being positioned in the top section of the compartment and the lower end being positioned in the bottom section of the compartment,the improvement comprising:1.

Abstract: A horizontal furnace for converting nonferrous metal sulfide concentrates to a molten matte has a plurality of vertically disposed burners along the longitudinal axis of the furnace roof, the burners spaced from each other, means for introducing oxygen-rich gas to said burners, and means for introducing metal sulfide concentrates and flux into the furnace, with the spaced burners introducing the same into the hot atmosphere of the furnace as a plurality of paraboloidal suspensions whereby substantially uniform heat and mass distribution is effected over a major portion of the horizontal furnace.

Abstract: A method for enhancing chemical reactions in a constantly flowing stream of liquid character fortified with oxidizing agents, such as air or oxygen or other chemical agents, makes use of an inner resonant tube concentrically mounted within an outer resonant tube with the walls of the tubes spaced from each other forming an annular passageway for the flow of liquid from one end of the passageway to the other. One or more sets of radially spaced ultrasonic transducers are located on the outside wall of the outer resonant tube thereby to create an ultrasonic cavitation condition in the liquid as it flows through the annular passageway.

Abstract: Precious metals such as gold and silver are recovered from difficult-to-treat ores, particularly those containing manganese, by lixiviating using an ammonium thiosulfate leach solution containing copper, sufficient ammonia to maintain a pH of at least 7.0, and at least 0.05% sulfite ion, sulfite and thiosulfate requirements being maintained by the reaction in situ of sulfur dioxide and elemental sulfur.

Abstract: A method of producing inexpensive .beta.-silicon carbide at a relatively low temperature and in a high yield, wherein a raw material mixture consisting of carbonaceous powder having a particle size of not larger than 60 .mu.m and silica powder having a particle size of not larger than 150 .mu.m is continuously heated in a reaction system having a high temperature zone and a low temperature zone to form silicon monoxide in the reaction system together with SiC; the silicon monoxide is condensed at the low temperature zone to capture and is recovered in the reaction product; and the recovered product during the reaction or after the reaction is stirred, mixed and pulverized.

Abstract: A continuous process for the reduction of sulfur dioxide to sulfur in which a gas stream containing sulfur dioxide is contacted with a carbon source in the form of particulate coal at a temperature of at least 600.degree. C. in a plasma arc reaction zone generated by a rotating direct current arc.

Abstract: A thiosulfate-containing purge stream generated in a Stretford-type process for purifying a hydrogen sulfide contaminated gas stream is treated with a nickel ethylenediamine complex to remove thiosulfate as a nickel ethylenediamine thiosulfate precipitate. The precipitate is treated with acid to decompose the thiosulfate and then with lime to recover the nickel ethylenediamine complex for reuse.

Abstract: The present invention relates to a process for the manufacture of potassium nitrate with co-production of relatively concentrated aqueous solution of hydrochloric acid.According to the invention, potassium chloride and nitric acid are reacted in the medium of an organic solvent selected from butanols and pentanols. The solution obtained after the separation of the resulting potassium nitrate, containing hydrochloric acid together with nitric acid and said organic solvent, is subsequently washed thus resulting an aqueous solution of hydrochloric acid which contains nitric acid. The nitric acid is extracted by an organic solvent selected from organic esters of phosphoric acid, ketones having five to ten carbon atoms and straight or cyclic polyethers having molecular weight in the range of 100 to 1000 and polyalkylene glycols which are slightly miscible in water and having molecular weight in the range of 1000 to 3000, or mixtures thereof, preferably in the presence of an organic diluent.

Abstract: A universal quench press is used for the precision quenching of gears, bearing rings, saw blades, slitting knives, cylindrical parts, flat parts, dished parts, and other articles. A set of quenching dies reduce or eliminate the distortions in size, roundness, taper, and flatness encountered in manufacturing processes prior to the press quenching process and/or operation. The press has a plurality of posts or tie-rods configured to distribute the forces of the applied loads uniformly. Provisions are made for a plurality of generally concentric rams with all of the rams powered by hydraulic or pnuematic cylinders or other force exerting device or devices to provide a uniform and evenly distributed force. An automatic quench media splash guard seals the quenching chamber during operation and requires absolutely no set-up or operating adjustments or changes.

Abstract: In the process for reducing the total sulfur content of a high CO.sub.2 -content feed gas stream, the feed gas is first passed to an absorption column. The unabsorbed, high CO.sub.2 -content gas is then routed to a reduction step where it is combined with Claus off-gases and the sulfur compounds are reduced to H.sub.2 S. The treated gas is then passed to a second absorption column and the unabsorbed gas is vented to the atmosphere. The fat solvent from both absorption columns is stripped in a common stripper and the stripped gas is passed to a Claus unit for conversion to elemental sulfur.