Joernaal Van Die Suid-Afrikaanse Instituut Vir Mynbou & Metallurgie Volume 6 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 Excerpt: ...and Mining Journal, Oct. 14, l -o.-. (V. A. C.) METALLURGY. XKW PROCESSES FOR THE EXTRACTION OK LEAD.--"An important improvement in the metallurgy of lead has been effected by the introduction of the Hiintington-Heberlein process, which consists in heating a mixture of galena and lime at 700"C, then cooling to alniut 500C. and passing a current of air through the mass, when sulphur dioxide is evolved. The process is continuous, the atmospheric oxygen interacting with the ore so long as any sulphur is present. In the riradford-Carmichael process gypsum or anhydrite takes the place of lime, either of these minerals in the form of a sludge being intimately mixed with the lead ores and the dried mixture lx-ing subsequently heated in a stream of air. The issuing gases, which contain about 10 per cent, of sulphur dioxide, may be utilised in the production of sulphuric acid. Two alternative explanations are given of the former of these processes, the first being that the lime becomes oxidised to calcium peroxide at 70OC. and that this compound is "S-c this Journal, p. I.HS, Oct., 190.." decomposed at 500," the oxynen set free oxidising the lead sulphide to lead sulphate. This sulphate then reacts with more sulphide yielding lead oxide and sulphur dioxide. The second hypothesis i that the lime and galena interact to form le-d oxide and calcium sulphite, the latter compound then becoming oxidised to calcium sulphite or sulphate which partly becomes converted into calcium plumbite or pliimbate while the remainder reacts with galena forming calcium sulphide and lead sulphate."'-Chemisettes Central-Malt, August 10. 1905.--The Times (London) Engineering Supplement, Sept. 27, 1905. (V. A. C.) Nomenclature Of Ore Reduction.--&q...