Abstract: An improved method for processing of nickel-bearing ores, particularly saprolite and limonite, to recover the valuable minerals contained therein, comprising leaching the ore with nitric acid to form a slurry; separating the iron values by precipitation, removing the iron values; forming a liquid/solid residue in which nickel, cobalt and magnesium are in solution, and manganese and aluminum, when present, are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and nitric acid from the leachate is recycled.

Abstract: An improved method for processing of nickel-bearing ores, particularly saprolite and limonite, to recover the valuable minerals contained therein, comprising leaching the ore with nitric acid to form a slurry; separating the iron values by precipitation, removing the iron values; forming a liquid/solid residue in which nickel, cobalt and magnesium are in solution, and manganese and aluminum, when present, are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and nitric acid from the leachate is recycled.

Abstract: An improved method for processing of nickel bearing saprolite and limonite ores to recover the valuable minerals contained therein, comprising leaching the ore with nitric acid to form a slurry; separating the iron values by precipitation, removing the iron values; forming a liquid/solid residue in which nickel, cobalt and magnesium are in solution, and manganese and aluminum are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and nitric acid from the leachate is recycled.

Abstract: An improved method for processing of nickel-bearing ores, laterite ores, saprolite and limonite ores, oxidic and sulfide ores, metallurgical wastes, and other metal-bearing materials, to recover the valuable minerals contained therein, comprising comminuting ore to a desired size; leaching the ore at about 70 C to 130 C for about 30 minutes to 4 hours with nitric acid, raising the temperature of the solution to form a liquid/solid residue in which nickel, cobalt and magnesium values are in solution, and iron, manganese, and aluminum are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and the nitric acid from the leachate is recycled.

Abstract: An improved method for processing of nickel-bearing ores, laterite ores, saprolite and limonite ores, oxidic and sulfide ores, metallurgical wastes, and other metal-bearing materials, to recover the valuable minerals contained therein, comprising comminuting ore to a desired size; leaching the ore at about 70 C to 130 C for about 30 minutes to 4 hours with nitric acid, raising the temperature of the solution to form a liquid/solid residue in which nickel, cobalt and magnesium values are in solution, and iron, manganese, and aluminum are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and the nitric acid from the leachate is recycled.

Abstract: An improved process for either the manufacturing of nitric acid, recycling of nitric acid, or recovering of nitric acid, comprising the steps of: providing a source of NOx; reacting NO from the source of NOx with HNO3 in the presence of NO2− to produce a resulting product; and reacting the resulting product with O2 and H2O to produce nitric acid.

Abstract: A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate and electrolyzing the leachate to separate Cd from Te, wherein the Te is deposits onto a cathode while the Cd remains in solution.

Abstract: A method of separating calcium from mixtures of metal oxides, sulfides, nitrates and carbonates. Particulate calcium containing mixtures are leached with nitric acid to form calcium nitrate and metal nitrates, which are heated to dryness and to form metal oxides, while not affecting the calcium nitrate. The resulting mixture is then leached with water to obtain a calcium nitrate containing leachate and a residue of low solubility metal oxides and insoluble metal oxides. If desired, the calcium nitrate can be decomposed to form a lime product.

Abstract: A treatment of metallurgical dust and recovery of valuable chemical commodities, comprising the steps of: leaching salts from the dust with water to create a washed EAF dust; reacting the washed EAF dust in a nitric acid solution resulting in a nearly complete dissolution of the zinc, cadmium, copper, magnesium, calcium, manganese and lead from a filtrate; removing iron from the filtrate by raising pH in the system with basic zinc carbonate; removing cadmium, copper and lead in an electrolytic cell, where copper and cadmium are collected at the cathode, and lead is collected at the anode; evaporating and decomposing the filtrate to obtain metal oxides and anhydrous calcium nitrate; leaching the solid residue with water to separate calcium nitrate in a marketable form; removing the zinc from the magnesium and manganese by leaching the residue with an amine solution; stripping the filtrate of ammonium carbonate to yield zinc precipitated as a zinc oxycarbonate; dividing the zinc oxycarbonate into a first stream

Abstract: A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the metals in dilute nitric acid, leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate, adding a calcium containing base to the leachate to precipitate Cd and Te, separating the precipitated Cd and Te from the leachate, and recovering the calcium-containing base.

Abstract: A method for extracting and reclaiming metals from scrap CIS photovoltaic cells and associated photovoltaic manufacturing waste by leaching the waste with dilute nitric acid, skimming any plastic material from the top of the leaching solution, separating glass substrate from the leachate, electrolyzing the leachate to plate a copper and selenium metal mixture onto a first cathode, replacing the cathode with a second cathode, re-electrolyzing the leachate to plate cadmium onto the second cathode, separating the copper from selenium, and evaporating the depleted leachate to yield a zinc and indium containing solid.

Abstract: A process for the accelerated fixing of fixable chromate-containing wood preservatives in which wood freshly impregnated by any of the full-cell, modified full-cell, empty-cell, or modified empty-cell treating processes are subjected to fixing by contacting the wood with hot liquid medium, such as water, which liquid is either initially hot or is rapidly heated to sufficient temperature so that the entire bundle of wood is brought to a temperature sufficient for fixation to occur within a short economic period of time within the liquid medium. The process also produces a low-weight preservative impregnated wood product.

Abstract: A method of preparing copper arsenate compositions having unique advantges in lower cost and higher performance for use in preparing chromated copper arsenate wood preserving formulations. These copper arsenate compositions are insoluble copper arsenate in water or as a dry reactive powder, have a mol ratio of As.sub.2 O.sub.5 to CuO of 1:4, and is readily soluble in chromic acid to form CCA wood preservatives. This copper arsenate is prepared by reacting suitable copper-bearing materials with arsenic trioxide and air or oxygen in ammoniacal solutions. Either or both of the starting raw materials, i.e., the copper and the arsenic, may be very impure, which impure materials were heretofore unsuitable for the production of copper arsenate.

Abstract: A process for the accelerated fixing of fixable chromate-containing wood preservatives in which wood freshly impregnated by any of the full-cell, modified full-cell, empty-cell, or modified empty-cell treating processes are subjected to fixing by contacting the wood with hot liquid medium, such as water, which liquid is either initially hot or is rapidly heated to sufficient temperature so that the entire bundle of wood is brought to a temperature sufficient for complete fixation to occur within an economic period of time either within or after removal from the liquid medium.

Abstract: A method for the direct extraction of metal values from subterranean sulfide ore deposits is described utilizing electrochemical techniques. The method eliminates the physical digging and crushing of ore. The process can be controlled to extract only the metal values and other useful chemicals from the earth deposit, thus reducing waste disposal and environmental pollution problems. The prior art difficulty with polarization of the electrodes is overcome by utilizing electrolytes of high halogen ion content, thus eliminating insulating sulfur buildups and permitting economical usage of higher current densities.

Abstract: A method is described for the direct extraction of copper as finely divided metal from subterranean sulfide ore deposits containing the same utilizing electrochemical techniques. The method eliminates the physical digging and crushing of ore and greatly reduces subsequent refining and further purification of the recovered copper. Copper produced in accordance with the method can, in many instances, be used in the recovered form. Alternative processing techniques are described for simultaneously producing both finely divided copper and finely divided iron from sulfide ores containing the same.