Abstract: The invention relates to a method of recovering molybdenum from a molybdenum bearing sulfide material. The material is contacted with a leaching solution in the presence of iron compounds and mesophilic or thermophilic iron oxidizing microorganisms and subsequently, a leaching process is performed by controlling the molar ratio of dissolved ferric iron to dissolved molybdenum. Preferably, a high amount and molar excess of dissolved iron is used. The presence of high concentrations of ferric iron in bioleach solutions allows iron-oxidizing microorganisms to grow and oxidize iron and bioleach molybdenite at dissolved Mo concentrations as high as 4.4 g/L. Organic metabolites were not required for protecting cells from Mo toxicity. Maximum dissolution rates depend on reactor configuration, with agglomerated material simulating heap leaching of almost 1% Mo/day, but up to 10.2% Mo/day in suspension/stirred reactor configurations, with rate highly dependent on temperature within the range of 25° C. to 40° C.

Abstract: The invention relates to a method of recovering molybdenum from a molybdenum bearing sulfide material. The material is contacted with a leaching solution in the presence of iron compounds and mesophilic or thermophilic iron oxidizing microorganisms and subsequently, a leaching process is performed by controlling the molar ratio of dissolved ferric iron to dissolved molybdenum. Preferably, a high amount and molar excess of dissolved iron is used. The presence of high concentrations of ferric iron in bioleach solutions allows iron-oxidizing microorganisms to grow and oxidize iron and bioleach molybdenite at dissolved Mo concentrations as high as 4.4 g/L. Organic metabolites were not required for protecting cells from Mo toxicity. Maximum dissolution rates depend on reactor configuration, with agglomerated material simulating heap leaching of almost 1% Mo/day, but up to 10.2% Mo/day in suspension/stirred reactor configurations, with rate highly dependent on temperature within the range of 25° C. to 40° C.

Abstract: The present invention relates to calix[4]arenes which effectively bind alkali metal ions (Na+, K+) and transport them over phase boundaries, their preparation and use.

Abstract: The present invention relates to calix[4]arenes which effectively bind alkali metal ions (Na+, K+) and transport them over phase boundaries, their preparation and use.

Abstract: The invention relates to a method of extracting anions based on metals of groups IV B to VIII of the periodic table from aqueous solutions thereof, wherein compounds of general formula are used as extractants, in which a maximum of two of the R1, R2, R3 and R4 substituents represent hydrogen atoms and the remaining substituents represent identical or different alkyl or aminoakyl groups, which are optionally branched and which contain on average at least 5 C atoms.

Abstract: Tungstate solutions are purified by a precipitation process followed by two anion exchange processes to reduce molybdenum and arsenic impurity content. The precipitation involves acidification of the original highly basic tungstate solution to pH of 7 to 10 without addition of precipitating agents and separates out the bulk of impurities other than Mo, As. The first anion exchange process removes As. Then a remaining filtrate from the latter process is treated with sulfides to form thiomolybdates from impurity Mo content and the thiomolybdates are then separated out from the tungstate solution in a second anion exchange process.

Abstract: The present invention relates to cobalt metal agglomerates consisting of peanut-shaped primary particles with average particle sizes in the range from 0.5 to 2 .mu.m, to a process for the production thereof and to the use thereof.

Abstract: The present invention relates to a process for the production of pure ammonium metallates of the metals W, Mo, V, Cr and Re, wherein alkaline metal salt solutions are adjusted to a pH value in the range from 5 to 9 by reaction with CO.sub.2, these metal salt solutions are passed through an anion exchanger in carbonate form, wherein, in addition to the alkali metal carbonate solution, the metallate form of the ion exchanger is formed, the ion exchanger is then washed until free of alkali and is then eluted by means of aqueous ammonia to form ammonium metallate solutions and the anion exchanger in the OH form, wherein the anion exchanger is converted into the carbonate form by means of CO.sub.2 treatment and is recycled.

Abstract: Process for the production of pure tungsten and/or molybdenum solutions from sources, such as alkaline decomposition solutions, which are contaminated with tantalum, niobium, titanium, aluminium, tin, arsenic, phosphorus and/or silicon, by application of a three stage purification process of pH reduction, anion exchange and membrane electrolysis.

Abstract: An apparatus for effecting a coalescence in enriched aqueous solutions which contain germanium and/or arsenic is disclosed, said apparatus comprising an emulsion-breaking unit consisting of a breaking cell providing with two electrodes, which are disposed on opposite sides outside cell walls adjacent thereto, and terminals for electric power, the electrodes and the breaking cell being contained in a container which is filled with an insulating medium and surrounded by a Faraday cage, a line for supplying emulsion to the breaking cell, a settling tank, a line for withdrawing the coalesced liquid and for transferring it to the settling tank, a line for withdrawing the membrane-forming organic phase from the settling tank, and means for recycling noncoalesced emulsion from the settling tank to the breaking cell.

Abstract: An emulsion-forming composition for forming an emulsion for use in a process for selectively recovering germanium or arsenic from an aqueous solution thereof by liquid membrane technology is disclosed, said composition consisting essentially of: a solvent mixture consisting essentially of specified amounts of a hydrocarbon which is a predominantly straight-chain saturated C.sub.16 -C.sub.20 hydrocarbon or kerosine, a mononuclear aromatic hydrocarbon (pref. xylene), and a halogenated C.sub.1 -C.sub.5 hydrocarbon (pref. CCl.sub.4); and more than 0.1% by weight of an oil-soluble polyisobutylene-succinic anhydride/polyamine condensation product.

Abstract: A process for extracting germanium and/or arsenic from an aqueous solution is described. In order to increase the yield and to perform a highly specific separating process, the liquid membrane technology is employed, in which the starting solution is adjusted by means of hydrochloric acid to a concentration in excess of 6 and up to 10 moles HCl/1, a polyisobutylenesuccinic anhydride/polyamine condensation product is used as a surfactant in the organic outer phase of the liquid membrane emulsion is adjusted to a pH value from 0 to 14 while a supply of chlorine ions is precluded.