Abstract: Feed material, such as matte, containing nickel and copper values and sulfur, is leached with an acidic copper sulfate solution to dissolve nickel, cobalt and other metal values and to cement copper from solution. The leach residue is roasted, and a selected quantity of copper is leached from the resulting calcine with sulfuric acid to form a copper sulfate electrolyte. The rest of the calcine is smelted to form copper-nickel anodes which are electrorefined in the copper sulfate electrolyte, thereby producing a cathodic copper deposit and a nickel-enriched, copper sulfate electrolyte which is recycled for leaching additional feed material.

Abstract: In a copper refinery including smelting, converting and electrolytic refining steps, feed material containing copper and contaminated with iron and one or more impurity metals selected from the group consisting of nickel, antimony, and tin is refined in a process in which the impurity metals are separated from the copper prior to the main electrolytic refining step, into a converter slag product that is subsequently smelted to form anodes which are electrolyzed in a portion of the main copper refinery electrolyte.In another embodiment, oxidic (e.g. roasted) copper and copper-nickel concentrates are individually smelted to form anodes which are electrolyzed in separate cells between which electrolyte is cycled to maintain a balance of dissolved copper.

Abstract: A solar hot-water system having an absorber formed of plastic ducting adapted to be arranged unobtrusively on a roof surface whereby the water is heated by means of direct radiation from the sun and by means of conduction from the roof surface on which the ducting is supported.

Abstract: A method is provided for extracting silver from a silver sulfate-bearing substance, such as oxide materials, metal or metal sulfate mixtures containing silver sulfate which comprises subjecting said substance to aqueous leaching to remove soluble salts therefrom and leave a residue, taking the residue containing silver sulfate and other insoluble materials, such as insoluble salts, and forming a slurry with an aqueous solution of a metal sulfate, such as calcium nitrate, the amount of calcium nitrate being at least sufficient to effect metathetical exchange with the silver sulfate and form a silver nitrate solution containing substantially the silver originally present in the silver-sulfate bearing substance, and separating the silver nitrate solution from the residue remaining, and then purifying said solution, the silver being thereafter recovered from the silver nitrate solution by hydrolytic precipitation, electrowinning or other suitable means.