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Ferrite magnet industrial waste liquid, waste residue

2018-07-25
Ferrite magnet industrial waste liquid, waste residue

Pyrite slag is mainly derived from industrial waste residue from the production of sulfuric acid from pyrite. Usually, 0.9 t of waste residue is produced per 1 t of sulfuric acid produced. About 7 million tons of waste residue is produced annually in China. The main components of pyrite waste are Fe203, Fe3 04, SiO 2 and Al 203.
The iron oxide magnet is made of pyrite slag: first, the pyrite slag is carbonized and calcined at a high temperature for reduction treatment, and all the high-priced iron therein is changed into FeO, then sulfuric acid is added to form FeS04, and the solid impurities are removed by filtration. Fe(0H)2 is obtained by using aqueous ammonia to oxidize Fe(OH)2 to iron oxide yellow by air. The iron oxide yellow is subjected to calcination and dehydration to obtain iron oxide red.
Steel pickling solution is a large amount of waste acid (60-250 g per liter of ferrous salt) produced by pickling in steel mills (or other metal surface treatments). The waste acid is directly calcined, and under the conditions of high temperature, oxygen and water, FeCl2 is hydrolyzed to obtain Fe203. The waste acid produced in other industries can also be obtained by adding iron filings or iron sheets, and then making ferrous salts, and then roasting to obtain Fe203.
The titanium white by-product is produced by the process of producing titanium dioxide by the sulfuric acid method, and generally produces about 8 to 10 t of waste acid and 2.5 to 3.5 t of ferrous sulfate (green strontium) per 1 t of titanium dioxide produced. Green sputum can produce iron yellow by sodium gasification gasification method and air oxidation method. Other available raw materials include iron sludge discharged from the production of indigo and m-phenylenediamine intermediates in the dyeing plant, iron sludge produced in the production process of medicine, electrolysis, metallurgy and fine chemicals, and iron sludge after wastewater treatment. , as well as discarded steel products.