METHOD FOR PRODUCTION OF CONCENTRATE OF MICROELEMENTS Russian patent published in 1997 - IPC

FIELD: production of microelements. SUBSTANCE: slime of clarifying constructions of production of electric lamps is used for neutralization of etching waste. Slime is used as solution of etching of molybdenum core in the mixture of concentrated sulfuric acid, nitric acid and water at their volume ratio 3:5:7 which comprises 25-40 g/l of molybdenum and/or as solution of etching of ferrum core in mixture of acids with water which comprises 280-330 g/l of ferrum. Mentioned above solutions are mixed at their volume ratio 0-1:1-0 and initially neutralized to pH 2.0-3.5. Then neutralization pH 6-8 takes place. Said slime comprises (as calculated for absolutely dry product), %: ferrum, 10.8-22.8; zinc, 11.5-0.6; nickel, 0.4-2.9; molybdenum, 0-2.3; copper, 0.2-1.3; calcium oxide, 30.0-16.0; magnesium oxide, 0.8-9.0; silicium oxide, 11.0-3.8; boron, 0.02-0.01, chromium, trace amount. Moisture content of slime is 65-70 %. EFFECT: improved efficiency. 2 tbl