Abstract: Lithium hexafluoroarsenate containing impurities, such as LiAsF.sub.5 OH HF, is purified by passing a solution of the impure product in an organic solvent, such as methyl formate, through a column of activated alumina which selectively adsorbs and removes such impurities.

Abstract: A colloidal dispersion of hydrous antimony pentoxide particles is made by a process which comprises introducing particles of an oxidizable antimony oxide into an aliphatic polyhydroxy alcohol having vicinal hydroxyl groups and contacting said particles with aqueous hydrogen peroxide at a temperature of from about 0.degree. C to about the decomposition temperature of the reaction mixture for a length of time sufficient to convert at least a portion of said particles to colloidal particles of hydrous antimony pentoxide.

Abstract: A process is disclosed for treating mixed metal sulfides containing trivalent antimony sulfide wherein the sulfide concentrates are leached with an excess of sodium sulfide in order to isolate copper sulfide and other insolubles in solid form while solubilizing the remaining metal sulfides and producing sodium thioantimonite, separating the insoluble sulfides from the solution; oxidizing the sodium thioantimonite with elemental sulfur to produce sodium thioantimonate in solution; crystallizing a portion of the sodium thioantimonate along with other available metal sulfides from solution; and recirculating the remainder of the solution to the sodium sulfide leach stage. The crystallized metal sulfides may be further treated, isolated, and recovered as desired.

Abstract: A process for the adsorptive removal of one or more impurity elements, selected from the group which consists of: arsenic, antimony and bismuth, from an aqueous solution containing same in which the solution is contacted with a water-insoluble or low-solubility salt of phosphoric acid or a phosphoric acid ester (phosphate ester) on a porous substrate.

Abstract: A process is disclosed for separating antimony sulfides from solutions comprising anitmony sulfides and arsenic sulfides by subjecting the solution to partial oxidation within prescribed pH limits in order to oxidize and precipitate a substantial portion of the antimony sulfides while leaving substantially all of the arsenic sulfides in solution.

Abstract: Molybdenum is selectively extracted from an aqueous solution containing various other metal values, e.g. copper, arsenic, iron, bismuth, antimony, tin, and lead in addition to molybdenum. The molybdenum-bearing solution is adjusted to a pH of about 2.0 or less, and, then, intimately contacted with an organic extracting solution containing an alpha-hydroxy oxime. The loaded organic phase, containing extracted molybdenum values, is separated from the aqueous raffinate, and the molybdenum values contained in the organic phase are stripped therefrom using an aqueous stripping solution containing ammonium hydroxide. The efficiency with which the molybdenum is stripped from the loaded organic solution is poor unless nonylphenol is present in the organic solution as it is being stripped. The nonylphenol can be added to the system anytime prior to the ammonium hydroxide stripping step, e.g.

Abstract: Disclosed is a process for the recovery of antimony pentachloride from catalyst solutions used in the fluorination of chlorinated hydrocarbons characterized in that the exhausted catalyst solution containing antimony ions and high boiling halogenated hydrocarbons is chlorinated to convert the Sb.sup.3.sup.+ to Sb.sup.5.sup.+ followed by treatment of the solution with hydrogen fluoride to give SbCl.sub.x F.sub.y compounds, wherein x is 4-2 and y is 1-3, the sum of x+y being 5, and to convert the high boiling halogenated hydrocarbons to lower boiling halogenated hydrocarbons, thereafter removing the halogenated hydrocarbons having a lower boiling temperature than the boiling point of SbCl.sub.x F.sub.y and converting the remaining SbCl.sub.x F.sub.y compound with carbon tetrachloride to form antimony pentachloride which is thereafter separated from the remaining organic compounds and inorganic residue.

Abstract: Complex sulfide ores or concentrates are decomposed by treatment with a combination of chlorine and oxygen, the amount of chlorine being limited to that necessary to convert sulfides of the desired metals, such as zinc, lead, copper, cadmium, silver, nickel and cobalt to chlorides.

Abstract: In an epitaxial growth method in liquid phase for III-V compound semiconductor crystals a solution for crystal growth is at first heated to a temperature which is higher than the temperature of crystal growth, and then cooled to that temperature, whereby a part of the solution crystallizes out as small crystals. This solution is separated by means of a filter means into two parts, one of which contains the small crystals and the other of which does not. A substrate crystal is brought into contact with the latter.

Abstract: Tetrahedrite ore concentrate, sodium sulfide added as such or formed in situ, calcium values preferably supplied as lime, and a reducing agent, e.g. coke, are smelted for a period sufficient to convert a major portion or substantially all of the antimony to a water-soluble sodium compound of antimony and sulfur and a major portion or substantially all of the arsenic also contained in the concentrate to a water-insoluble calcium compound of arsenic and oxygen. The sodium sulfide is incorporated into the charge for the smelting in an amount sufficient to convert at least a major portion of the antimony into the water-soluble sodium compound of antimony and sulfur; and the lime is incorporated into the smelting charge in amount sufficient to convert at least a major portion of the arsenic into the water-insoluble calcium compound of arsenic and oxygen.

Abstract: A process for the removal and recovery of bismuth from oxidized particulate materials, such as flue dust residue and/or roasted concentrates, the process including selectively solubilizing bismuth with an acidic chloride leach at an elevated temperature and thereafter separating the solubilized bismuth from the remaining metallic values in the residue.

Abstract: Aqueous AlF.sub.3 enriched crystallization mother liquors contaminated with P.sub.2 O.sub.5 values and having less than 5% free acidity are treated with a material which provides bismuth ions in the mother liquor in amounts small enough to insure that the Bi/PO.sub.4 mole ratio remains below about 1.05. Under these conditions, the bismuth and P.sub.2 O.sub.5 react essentially quantitatively to form a BiPO.sub.4 precipitate by which the P.sub.2 O.sub.5 can be separated from the mother liquor. Bismuth can be regenerated from the BiPO.sub.4 and recycled for further use in the process.The invention finds utility in the preparation of AlF.sub.3 by the reaction of an aluminum ore and P.sub.2 O.sub.5 contaminated HF or H.sub.2 SiF.sub.6 such as that available as a by-product of wet process phosphoric acid manufacture. The AlF.sub.3 reaction product is recovered by a crystallization step which, because it is normally only about 70 to 90% efficient, produces a mother liquor containing substantial amounts of AlF.sub.3.

Abstract: A hydrometallurgical process for treating iron containing metal sulfides for rendering iron and non-ferrous metal values active and amenable for selective extraction and separate recovery. Sulfur values can be controllably produced as elemental sulfur or as sulfuric acid to supply acid requirements of the process, while substantially obviating the discharge of sulfur-containing gases to the atmosphere. Ores and concentrates of the sulfides are thermally activated by sequentially heating and reducing said sulfides in a countercurrent flow of heating and reducing gases respectively in a reactor whereby the reaction products of the reducing gas and sulfides, together with liberated labile sulfur, are controllably combusted with oxygen to satisfy heat requirements of the thermal activation process and to convert sulfur values to SO.sub.2 gas. The activated sulfides are subjected to an acid leach in aqueous sulfuric acid for production of ferrous sulfate and evolution of H.sub.

Abstract: A seed holder for holding a seed crystal of gallium arsenide (GaAs) is fitted into one end of a cylindrical quartz boat in which a melt of gallium (Ga) and arsenic (As) is synthesized and then grown as a single crystal seeded by the seed crystal using the Bridgeman process or the gradient freeze process. The seed holder closely encompasses three sides of a crystal (e.g., of rectangular cross section) while exposing only the end upon which the crystal growth is to take place. The exposed end of the crystal seed is disposed above the bottom of the boat to prevent contact between the gallium melt and the seed until synthesis is nearly complete.