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Название публикации: «THE RELEVANCE AND STATISTICS OF THE LAST
FIVE YEARS OF LEAD PRODUCTION» UDC 669.431.22 Abstract. Article describes the main technologies for producing lead. The article also presents and analyzes statistical data on world lead production over the past five years. The positive and negative aspects of the technologies used are determined, the author's position on the most effective methods of lead production is expressed. The processes of electrolytic refining of crude lead with antimony and bismuth in solutions are considered. A long-term electrolysis of crude lead was carried out in an electrolyzer of an original design, which uses a porous ceramic diaphragm impregnated with chloride electrolyte H 2 SiF 6 (8-10%) and lead fluorosilicate - PbSiF 6 (6-8%). According to the results of electrolytic refining of crude lead, the coefficients of purification of lead from antimony and bismuth were calculated. The obtained values of the purification coefficients of lead from antimony and bismuth confirm the high efficiency of the process of electrolytic refining of crude lead from Sb and Bi in an electrolyte solution of lead. Keywords: lead, production, ore, preparing, agglomeration, smelting, shaft furnace, blister lead, fire refining, electrolytic refining. 154 1. INTRODUCTION Lead is a silvery-white, heavy metal with a density of 11.35 g/sm 3 and is malleable. The melting point is 327 o C, and the boiling point is 1749 o C, crystal lattice: in the form of a concentric cube. Lead and its compounds are very toxic. In Dmitri Mendeleev's periodic table of chemical elements, it is on the 82 nd place, in group IV, and has an atomic mass of 207.19 [1-23]. It is used in the production of lead batteries, in the field of varnishes, insecticides, in the preparation of crystal glass, in the preparation of printing house seals. In addition, it is used in the preparation of capsules for the storage of radioactive substances, in the preparation of cheap “Pewter” alloy (Sn 85-95%, Pb 15-10%), an alloy for welding in electronics (67% Pb and 33% Sn) and bearings. Alchemists compared lead metal to the planet Saturn [24-32]. The average amount of lead in the earth's crust is 0.0016%, and in ore it is around 1–2%. The main raw material for lead production is complex polymetallic ores. In addition to lead, the ore contains Zn, Cu, Fe, Cd, Bi, Sn, As, Au, Sb, Ti, Ge and other elements [33-45]. Minerals of lead are PbS – galena lead glitter, 3PbS*Sb 2 S 3 – boulangerite, PbO – glyot, Pb 3 O 4 – lead suric. More than 85-90% of lead is found in the form of galena in sulphide ores [46-51]. Mines are located in areas such as Khandiza, Kurgoshinkon, Koshmansoi, Miskon which situated in Uzbekistan [52-55]. Download 1.46 Mb. Do'stlaringiz bilan baham: |
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