Abstract: Process for adjusting the composition of a zinc alloy for the galvanization of steels, the alloy having a composition including the following components expressed in ppm (by weight): lead: 1,000 to 15,000, and as additives aluminium: 100 to 5,000, tin: 300 to 20,000, and magnesium: 10 to 1,000 and being deficient in at least one of said additives, said process comprising adding to the zinc alloy one or more metal compositions which are soluble in molten zinc and which contain a relatively high proportion of the additive in which the alloy is deficient, the amount of the or each metal composition being sufficient to compensate the deficit of the additive. The tin composition is virtually pure tin; the magnesium composition is a ternary alloy of zinc, magnesium (5,000 to 50,000 ppm) and aluminium (10 to 500 ppm); and the aluminium composition is a binary zinc/aluminium alloy containing about 5% of aluminium.

Abstract: The anodes for the electrolytic production of zinc from acid aqueous solutions of sulphate comprise a skin portion formed by conventional anode metal, lead containing from 0.25 to 1.0% silver, and a stiffening reinforcing member of titanium or zirconium. The reduction in thickness of the anodes, which is made possible by the provision of the reinforcing member, results in a substantial saving in the amount of silver-bearing lead which is immobilized, and a substantial reduction in the unit weight of the anodes. The resistance of the lead to anodic corrosion in a sulphuric acid medium is maintained and the resistance to corrosion by passivation of the reinforcing member permits the reinforcing member to be accidentally exposed, without disadvantage. To produce the anodes, the reinforcing members are clad with lead at a temperature of more than 100.degree. by rolling sheets of lead, by casting in a mould or by spraying on molten lead.

Abstract: An alloy suitable for the galvanization of steels by an immersion galvanization process, including gavanization of steels containing silicon, which alloy comprises zinc of commercial purity and has a lead content of the order of 1000 to 20000 p.p.m. by weight, an aluminium content of from 100 to 5000 p.p.m. by weight, a magnesium content of from 10 to 1000 p.p.m. by weight and a tin content of from 300 to 20000 p.p.m. by weight.A galvanization process using the said alloy is also described.

Abstract: An alloy suitable for the galvanization of steels by an immersion galvanization process, including gavanization of steels containing silicon, which alloy comprises zinc of commercial purity and has a lead content of the order of 1,000 to 20,000 p.p.m. by weight, an aluminium content of from 100 to 5,000 p.p.m. by weight, a magnesium content of from 10 to 1,000 p.p.m. by weight and a tin content of from 300 to 20,000 p.p.m. by weight.A galvanization process using the said alloy is also described.

Abstract: Solution and procedure of depositing a coating on the surfaces of zinc-coated ferrous metal parts which protects against corrosion in the presence of water. The solution is made up by adding to water, perliter of final solution, of 1 to 40 grams of sodium metasilicate, 14 to 40 milliliters of phosphoric acid, specific gravity 1.71, from 1 to 40 grams of sodium nitrate, from 10 to 50 grams of anhydrous zinc chloride and the pH is adjusted to a value between 2.3 and 3.8. Preferably nickel chloride is added. For use, the solution is heated to a temperature ranging from 15.degree. to 75.degree. C and brought into contact with the parts to be treated for a period from 20 to 72 hours. The deposit is continuous, hard, resistant to shocks and abrasion and imparts an efficient and lasting protection to galvanized parts in corrosive waters. The invention is useful for the protection of piping in the building industry.

Abstract: Solution and procedure of depositing a coating on the surfaces of zinc-coated ferrous metal parts which protects against corrosion in the presence of water. The solution is made up by adding to water, per liter of final solution, of 1 to 40 grams of sodium metasilicate, 14 to 40 milliliters of phosphoric acid, density 1.71 g/ml, from 1 to 40 grams of sodium nitrate, from 10 to 50 grams of anhydrous zinc chloride and the pH is adjusted to a value between 2.3 and 3.8. Preferably nickel chloride is added. For use, the solution is heated to a temperature ranging from 15.degree. to 75.degree. C and brought into contact with the parts to be treated for a period from 20 to 72 hours. The deposit is continuous, hard, resistant to shocks and abrasion and imparts an efficient and lasting protection to galvanized parts in corrosive waters. The invention is useful for the protection of piping in the building industry.

Abstract: Process for the recovery of pigment-grade iron oxide and technical hydrochloric acid of predetermined molarity, from iron chloride solutions such as pickling solutions containing hydrochloric acid. The iron chloride solution is concentrated until the molarity of the chloride ion therein is the same as the molarity of the hydrochloric acid which it is desired to produce. Concentrated sulfuric acid in slight stoichiometric excess relative to the iron, is then added to the iron chloride solution, which solution is thereafter evaporated to dryness. The distillation from this evaporation is hydrochloric acid of the predetermined molarity, and the dry residue is iron sulfate. The iron sulfate is calcined to drive off sulfur dioxide and sulfur trioxide and to leave iron oxide which may contain sulfates; and to remove these latter, the iron oxide is leached with dilute hydrochloric acid and is thereafter washed with water. The washed iron oxide is dried and micropulverized to produce a red iron oxide pigment.

Abstract: A process of leaching silicated zinc ores with sulfuric acid in which the ore is reacted at elevated temperature with at least a stoichiometric amount of sulfuric acid, treating products of the reaction with a predetermined quantity of hot water, filtering the zinc sulfate solution from precipitated silica, washing with a further predetermined quantity of hot water (the total amount of hot water used being determined so as to obtain the desired concentration of zinc in solution). The zinc is later recovered electrolytically. A 1 to 6N sulfuric acid solution may be used in which case a gelatinous mass is formed upon reaction and then it is evaporated at 100.degree. C of at least 60% of its water content. Alternatively the ore can be malaxated with about 20% stoichiometric excess concentrated sulfuric acid, and filtered at out at elevated temperature.

Abstract: A process for the re-utilization of the sulphate residues from the electrolytic treatment of zinc.The residues are digested hot with concentrated HCl in the presence of CaCl.sub.2. PbCl.sub.2 crystallizes on cooling. FeCl.sub.3 is extracted with TBP circulating in the direction of a series of columns and FeCl.sub.3 is extracted in a first column, washed in a second column and re-extracted a third column. The solution which issues is treated with NH.sub.3, resulting in precipitation of the majority of the hydroxides of the metals contained therein, which are subsequently separated, while Ag, Zn and Cu are complexed. Ag is precipitated with (NH.sub.4).sub.2 S.NH.sub.3 is recovered by means of lime. CaCl.sub.2 is re-cycled to the start of the process and Cu and Zn are leached together with the mineral.Application of the process to the recovery of the metals contained in the residues from the digestion of blends.