Recovery of Arsenic from Ores and Concentrates.
Flynn-CM Jr.; Carnahan-TG
U S Appl 440 893 7/11/83 11 PP Chem Abstr 99:91 696Q :11 pages
Arsenic is recovered as as2o3 from arsenical ores or concentrates by leaching with a hot acidic ferric salt solution (100 deg-200 deg c) followed by cooling of the leach solution to precipitate as2o3. Thus, concentrates were boiled with a hydrous fe2(so4)3 and h2so4 (30.8 pct) solution for 6 h. The slurries were filtered while hot to separate leach residue and precipitated sulfates from the pregnant solution. The filter cakes were washed with 10-20 ml of water and filtrate and washings were cooled for as2o3 crystallization. After filtration, the crude as2o3 filter cakes were stirred with dilute h2so4 to dissolve the soluble salts and filtered to recover the as2o3 (98 pct pure). This product contained <0.1 pct fe and <0.01 pct CO or cu.
U.S. Appl. 440,893, 7/11/83, 11 PP., Chem. Abstr. 99:91,696Q