GB324902A - Process for smelting ores to metal, matte and slag - Google Patents

Abstract

324,902. Skappel, H. Aug. 3, 1928. Extracting.-In a method of smelting iron ores, particularly sulphide ores, in which there are obtained separate layers of metal, matte, and a slag containing less than 15 per cent of iron oxide, the composition of the ore is ascertained and the amount of matte that will be formed from a given charge is calculated; there is then added a sufficient amount of a sulphide having a heat of formation of at least 40 kilogram-calories per gram-atom of sulphur, such as sulphides of aluminium, zinc, manganese, magnesium, or alkali or alkaline earth metals, or materials such as sulphates and carbon which will produce such sulphides, to raise the mean heat of formation of the matte above 25 kilogram-calories per gram-atom of sulphur, where upon the charge is smelted with the usual additions. Iron ores containing some manganese may be smelted with the addition of manganese sulphide, yielding a slag containing about 7 per cent of iron oxide and sulphide and containing most of the phosphorus content of the ore, a matte containing about 50 per cent each of manganese and iron sulphides, and a crude pig iron low in manganese. Elements such as arsenic, antimony, nickel, cobalt, molybdenum, and platinum present in iron ores may be taken up in an iron speisse by adding also additional ferriferous material. In the application of the process to oxide ores, metals such as iron, chromium, and manganese may be transformed into sulphides by the use of sulphides of calcium, magnesium, or aluminium, and by regulating successive additions of sulphide the metals may be separated successively.