Abstract: The invention provides a hydrometallurgical process for recovering lead in essentially pure form from a sulphurized compound containing at least lead as a non-ferrous metal. The process involves treating the sulphurized compound with an aqueous lixiviating solution containing at least one chloride of a metal selected from the group consisting of copper, bismuth, antimony, arsenic, and silver, preferably cupric chloride, the quantity of said at least one chloride being less than or equal to that which is stoichiometrically required for the complete dissolution of the lead contained in the sulphurized compound, thereby to obtain a solution containing lead chloride and the chlorides of metals nobler than lead as impurities if originally present in the sulphurized lead compound, and an insoluble residue containing the sulphide of the metal of said at least one chloride, the sulphides of the non-ferrous metals originally present in the sulphurized compound, and free sulphur.

Abstract: Disclosed herein is an alloy for galvanizing objects of steel which have a concentration of silicon lower than 0.45% by weight. The alloy consists essentially of 0.5 to 1.5% by weight of lead, 0.005 to 0.2% by weight of germanium and the balance zinc. The alloy may further contain 0.001 to 0.05% by weight aluminum.

Abstract: Disclosed herein is an alloy for galvanizing object of steel which have a concentration of silicon lower than 0.45% by weight. The alloy consists essentially of 0.5 to 1.5% by weight of lead, 0.005 to 0.2% by weight of germanium and the balance zinc. The alloy may further contain 0.001 to 0.05% by weight aluminum.

Abstract: The present invention is directed to an apparatus for preparing a lead or copper metal by electrolysis in a cell having a cathode and an anode which are separated by a diaphragm. The surface of the cathode is arranged in a substantially vertical direction and has a sufficiently low density of sites of nucleation so that metallic particles which are formed from the sites keep their individuality in relation to the adjacent particles, until the particles reach a dimension of at least 100 micrometers. An electrolyte is circulated between the cathode and an anode parallel to the surface of the cathode at a flow rate in a laminar to weakly turbulent manner so that under the action of the weight of the particles and the force exercised by the flow of the electrolyte the metallic particles are detached and fall into the electrolyte and are collected and are removed from the bottom of the cell.

Abstract: The invention is concerned with a method for the selective dissolution of lead in relation to zinc that is present as a sulphurized compound.The method comprises treating said compound to lixiviation with a solution containing ferrous chloride, while bubbling a gas that contains oxygen through the lixiviating solution.

Abstract: A process for selective liquid-liquid extraction of germanium from an aqueous acidic liquor containing, besides germanium, at least one other metal selected from the group which comprises cadmium, zinc, cobalt, iron, arsenic and nickel. This process includes extracting germanium from said aqueous liquor by contacting said liquor with an organic medium containing a diluent and an extractant, said diluent being immiscible with said aqueous liquor. The major part of germanium passes from said aqueous liquor to an organic phase which is subsequently submitted to a stripping step by contacting with an alkaline medium, with formation of an aqueous phase containing the major part of germanium from said aqueous liquor.

Abstract: The invention relates to a process for removing nickel from lead chloride dissolved into chloride brine to obtain lead chloride solution wherein the nickel concentration is under 50 mg/liter. The present invention comprises the following steps:(a) adjusting the content of an element selected from the group of arsenic and antimony to a value of at least 1/5 of the concentration in nickel expressed in grams per liter;(b) contacting the solution from (a) with lead powder thus precipitating nickel and the said element selected from the group of arsenic and antimony.

Abstract: The present invention is a process for preparing a lead or copper metal by electrolysis in a cell having a cathode and an anode which are separated by a diaphragm, which comprises the steps of preparing an electrolyte containing a metal chloride to be prepared in at least one chloride of an alkali metal or alkaline-earth metal; circulating the electrolyte between the cathode and the anode parallel to the surface of the cathode, wherein the surface of the cathode is arranged in substantially a vertical direction and has a sufficiently low density of sites of nucleation so that the metallic particles which are formed from the sites keep their individuality in relation to the adjacent particles, until the particles reach a dimension of at least about 100 micrometers; maintaining the flow of the electrolyte along the length of the surface of the cathode in a laminary or weakly turbulent manner so that, under the action of their weight and of the forces exercised by the current of the electrolyte, the metallic par

Abstract: A lead additive containing a lead oxide and an alkaline silicate which is resistant to dusting, abrasion and segregation. The weight ratio of lead to alkaline silicate, calculated as PbO and SiO.sub.2, respectively, is greater than about 95:5; the moisture content is less than or equal to about 2%; and the density is less than about 5 g/cm.sup.3.The process for producing these additives involve forming a paste of the lead oxide and alkaline silicate, conditioning the paste to form granules and heat treating the granules.

Abstract: A process for selective liquid-liquid extraction of germanium from an aqueous acidic liquor containing, besides germanium, at least another metal selected from the group which comprises cadmium, zinc, cobalt and nickel. This process includes extracting germanium from said aqueous liquor by contacting said liquor with an organic medium containing a diluent and an extractant, said diluent being immiscible with said aqueous liquor. The major part of germanium passes from said aqueous liquor to an organic phase which is subsequently submitted to a stripping step by contacting with an alkaline medium, with formation of an aqueous phase containing the major part of germanium from said aqueous liquor.

Abstract: A process for the treatment of solutions of lead chloride, containing as impurities at least one metal chosen from the group consisting of silver, copper and bismuth. This process is characterized by the fact that it involves the following steps:(a) bringing the solution into contact with a cation exchange resin whose active group is a sulfhydryl group; and(b) recovery of the lead on the basis of the solution obtained in step (a).

Abstract: The invention provides a process for extracting zinc from a sulphur- and zinc-containing ore which involves (a) leaching the sulphur ore or concentrate with an aqueous solution of cupric chloride, which can be regenerated by means of a regenerating agent and air; (b) subjecting the solution thus obtained to liquid-liquid extraction by means of an organic phase, preferably containing a solvent, comprising an acid organophosphorus compound; and (c) recovering the zinc contained in the said organic phase after the said extraction, preferably by elution. If justified by the composition of the ore, the following optional recovery steps may then be performed:(1) if lead is present, recovery of lead by cementation (i.e., precipitation) or by crystallization of lead dichloride followed by cementation of the crystallizate;(2) if copper is present, recovery of copper by cementation or by liquid-liquid extraction; and(3) if precious metals, e.g.

Abstract: The invention provides a method for selectively solubilizing the non-ferrous metals contained in sulphurized ores and concentrates, with regard to the iron and sulphur therein, by subjecting the ore or concentrate to lixiviation with an aqueous solution of cupric chloride at a temperature above 50.degree. C., preferably at a temperature between 70.degree. C. and 105.degree. C., and then regenerating said aqueous solution in situ at atmospheric pressure by means of air and a regeneration agent selected from the group consisting of hydrochloric acid and ferrous chloride. The invention also contemplates the preferable inclusion in the aqueous cupric chloride solution of an agent for solubilizing cuprous chloride selected from the group consisting of an alkali metal chloride, an alkaline earth metal chloride, ammonium chloride, and ferrous chloride.

Abstract: A method and apparatus for controlling an autogenous or semiautogenous crusher, in which the quantity of charge within the crusher is determined continuously. The speed of rotation of the crusher is controlled in accordance with a function which links the speed of rotation of the crusher to the quantity of the charge in the crusher. In a preferred embodiment, the charge is determined from the resistance experienced by the motor which drives the crusher. This resistance is a linear function of the charge within the crusher. The control apparatus provides an electrical signal which is proportional to the quantity of charge and the electrical signal is then used to control the speed of rotation of the crusher.

Abstract: An agitator for use in flotation having a frusto-conical skirt attached to a central hub to the agitator. The agitator also having two layers of bars disposed symmetrically on the generatrices of two opposite, coaxial truncated cones mounted at their ends on circular bases, at least one base being perforated to allow passage of flotation medium, and the bases being connected by a hollow central hub of which an upper portion is adapted to receive pressurized gas and a lower portion is provided with at least one orifice for discharging the gas. The frusto-conical skirt is situated between the bars and the central hub, is coaxial with the hub and is attached at its upper end to the hub.

Abstract: The invention provides a process for recovering germanium as germanium oxide from a germaniferous metallic zinc which involves distilling the germaniferous metallic zinc under non-oxidizing conditions, recovering the distillation residue which contains the germanium, leaching the recovered distillation residue with chlorine water to convert the germanium into germanium tetrachloride, hydrolyzing the germanium tetrachloride into germanium oxide, and recovering the germanium oxide. Optionally, the germanium oxide may be reduced to metallic germanium, if desired.

Abstract: The invention provides a method for obtaining electrolytic copper from copper-bearing ores which involves (a) lixiviating a sulphurized copper concentrate with an aqueous solution containing cupric chloride; (b) separating the solution resulting from the lixiviation stage (a) into two parts, one of said parts, containing at least 1 gram of cuprous ions per liter and at least 2 grams of ferrous ions per liter, being subjected to oxidation by air at atmospheric pressure, at a pH value between 1 and 3, and at a temperature above 90.degree. C.

Abstract: A method for obtaining electrolytic copper and other useful metals from sulphurized concentrates, including in combination, the following stages:A. lixiviating the sulphurized concentrate with an aqueous solution containing cupric chloride formed in situ, at least in part, by oxidation, by introducing hydrochloric acid and air into the cuprous chloride solution resulting from lixiviation;B. partially extracting the copper contained in the lixiviation solution resulting from stage a) by contacting the lixiviation solution with an organic extractant containing a cationic solution, the extraction being accompanied by oxidation by injecting air into the lixiviation solution;C. re-extracting the copper contained in the organic extractant by contacting the organic extractant with an aqueous solution of sulphuric acid and recycling the organic extractant to the extraction stage b); andD.

Abstract: The invention provides a process for preventing the oxidation of liquid zinc, while at a temperature exceeding 500.degree. C, in a furnace heated by natural gas and utilizing at least one furnace burner, by injecting into the furnace atmosphere comprising air containing free oxygen (preferably an amount of free oxygen of less than 1.5% by volume), a quantity of sulphur dioxide in an amount between about 0.01% and 0.04%, by volume (preferably about 0.02%, by volume) with respect to the volume of the furnace atmosphere. The sulphur dioxide may be provided by low grade gases from a lead foundry or may be produced by the combustion of a sulphur-containing material.

Abstract: A method for selectively dissolving non-ferrous metals contained in pyritic ores by the steps of crushing the ores, introducing the crushed ore at a temperature above the ambient temperature into a reaction vessel containing a solution of chlorides of a metal having two valance states, and injecting gaseous chlorine into the reaction vessel at a rate such that the oxido-reduction potential of the solution of chlorides remains between 400 and 700 mv during the operation.