Abstract: A method for sequestrating arsenic oxides, comprising forming an insoluble and stable glass incorporating a fully oxidized form of arsenic generated by oxidation of an initial lower oxide of arsenic and stabilization by calcium salt formation. The glass composition for sequestration of arsenic comprises from 50 to 75% silica; from 0.5 to 3% Al2O3; from 1 to 15% MnO; from 5 to 15% CaO; from 1 to 20% As2O5 and from 8 to 14% Na2O, less than four percent of iron oxides, magnesium oxide and other oxides.

Abstract: A method for recovering precious metal from an acidic pregnant solution resulting from halogen or hypohalite leaching of an ore, comprising lowering the ORP of the pregnant leachate with a reducing agent in the presence of slurried non-carboneous particles. The precious metal deposits on the surfaces of the particles and a barren solution comprising substantially all the halogen values of the pregnant solution in the form of sodium chloride, sodium bromide or hypohalites is recovered.

Abstract: A method for selectively processing a polymetallic oxide solution containing a plurality of base metals comprising at least one of: Cu, Co, Ni, Zn associated with iron, comprising acid leaching the solution; recovering a filtered leachate; oxidizing the leachate; and adjusting the pH of the leachate in presence of a complexing agent; wherein the acidic solution is one of: i) a hydrochloric acid solution and ii) a sulfuric acid solution at a pH lower than about 1.5, and the complexing agent is one of: i) ammonium chloride and ii) ammonium sulfate, the step of adjusting the pH comprising raising the pH to a range between about 2.5 and about 3.5.

Abstract: A method for sequestrating arsenic oxides, comprising forming an insoluble and stable glass incorporating a fully oxidized form of arsenic generated by oxidation of an initial lower oxide of arsenic and stabilization by calcium salt formation. The glass composition for sequestration of arsenic comprises from 50 to 75% silica; from 0.5 to 3% Al2O3; from 1 to 15% MnO; from 5 to 15% CaO; from 1 to 20% As2O5 and from 8 to 14% Na2O, less than four percent of iron oxides, magnesium oxide and other oxides.

Abstract: A method and a system for the production of potassium sulfate. The method comprises reacting a chloride of potassium with a magnesium sulfate in an aqueous alcoholic solution, with recycling of magnesium sulfate and production of hydrochloric acid, where the recycling of magnesium is done by a reaction of sulfuric acid on resulting magnesium chloride with corresponding production of magnesium sulfate and hydrochloric acid.

Abstract: The invention relates to a method for the extraction of precious metals, using halogens. It has been found that introducing halogens in the reactor in the form of hypohalites rather than free halogens simplified greatly the recycling of halogens by electrolysis. It increases the rate of addition of the halogens and significantly reduces secondary reactions with base metals such as iron. Operating under acidic conditions, the gold recovery has been found as high with hypochlorite as with elemental chlorine, with an active chlorine to ore ratio reduced by a factor of two to five.

Abstract: A method and a system for the production of potassium sulfate. The method comprises reacting a source of water soluble potassium with a magnesium sulfate-containing substance in presence of an aqueous alcoholic solution.

Abstract: A process for producing potassium magnesium sulfate, comprising reacting sulfuric acid with potassium chloride and magnesium chloride at a temperature in a range comprised between about 100 and about 160° C., thereby producing potassium magnesium sulfate and hydrochloric acid, the sulfuric acid being reacted with potassium chloride and magnesium chloride simultaneously or sequentially.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

Abstract: Ores containing copper, zinc, silver in the form of sulfides are treated by a solution of sulfurated sulfite ions and ammonium ions in order to remove most of the metals from the sulfide ores. This treatment renders the resulting gold bearing ores much more amenable to cyanide extraction. Dissolved metals are reclaimed by appropriate techniques, such as electrowinning or liquid-liquid extraction, and the solution of sulfurated sulfites and ammonia is recycled for further lixiviation of fresh ores.

Abstract: A pressure-molded, rigid, high surface cathodic or anodic electrode of low electrical resistance and good mechanical strength and resistance to corrosion comprising non-dissolving, electrically-conducting metal particles of high specific surfaces and fractal structure which are bound with up to 15% by weight of aluminum phosphate.

Abstract: The present invention relates to a shaped, molded refractory and insulating product derived from the chemical bonding of muscovite, phlogopite or mixtures thereof with an acid aluminum phosphate having a ratio of Al:P of from 0.286 to 0.666 to which may be added an inert filler, a monofilament or oriented monofibers or woven fibers and which may have a metal cladding adhering to at least one surface of the shaped product.

Abstract: The invention relates to an improved process for the dehalogenation of polyhalogenated hydrocarbons from a fluid containing same wherein the dehalogenation is carried out through the reaction of sodium or potassium, which comprises contacting a dispersion of sodium or potassium over the surface of a particulate inert material having a density of at least 2.0 with a polyhalogenated hydrocarbon contaminated hydrocarbon oil, said mixture being in an inert atmosphere, heated to a temperature of at least 100.degree. C.

Abstract: The invention relates to a process for degrading polycyclic aromatic hydrocarbons adsorbed over chrysotile asbestos fibers which comprises oxidizing in the presence of moisture with ozone a mass of polycyclic aromatic hydrocarbons adsorbed on chrysotile asbestos fibers, whereby the hydrocarbons are degraded mainly to carbon dioxide and substantially pure chrysotile asbestos is recovered.

Abstract: There is disclosed an improved process for phosphating asbestos fibers by reacting phosphorus chlorides with asbestos fibers in a first reaction vessel heated to a temperature within the range of the boiling temperature of the selected phosphorus chloride at atmospheric pressure and 200.degree. C. above the boiling temperature of said phosphorus chloride, then the phosphated asbestos fibers are cured in a second chamber and purged of any volatile by-product formed during the phosphating step. The products obtained possess reduced haemolytic activity.

Abstract: There is disclosed a dry process for preparing magnesium sulfate by heating one surface of a reaction mixture of asbestos tailings to a temperature of from 350.degree. to 400.degree. C. whereby there is provided a gradient temperature between the heated zone, an intermediate zone and the outside zone where the ammonium bisulfate formed can condense in one of the last two zones which are at a temperature lower than 250.degree. C. and react with ammonia to provide a new supply of ammonium sulfate for further reaction with the asbestos tailings and recovering the magnesium sulfate thus obtained.

Abstract: A process for bleaching peat moss at acid pHs to produce a peat moss product of enhanced color and which substantially maintains its original structure.

Abstract: Substantially pure magnesium hydroxide or carbonate is obtained from naturally-occurring minerals containing at least 10% magnesium silicate by adjusting the pH a magnesium bisulfite solution obtained therefrom to between 8.0 and 8.9 under an oxidizing atmosphere thereby to produce a magnesium sulfate solution from which the magnesium hydroxide or carbonate can be readily obtained.