| 摘要 |
<p>1,127,223. Zinc recovery; leaching ferrites. COMPAGNIE ROYALE ASTURIENNE DES MINES. 24 Sept., 1965 [2 Oct., 1964], No. 40814/65. Heading C1A. Zinc is recovered from ferrites by leaching the ferrites with a sufficient excess of H 2 SO 4 to obtain, after breaking down the ferrites, an H 2 SO 4 concentration of not less than 180 gms/litre; separating the insoluble compounds from the resulting solution; increasing the volume of the solution with H 2 SO 4 having a concentration of 150-200 gms/litre; oxidizing with MnO 2 any ferrous ions that may exist; and reducing the acidity of the solution until a concentration of H 2 SO 4 of 3-5 gms/litre is obtained, to precipitate the iron present in the form of basic sulphate. The H 2 SO 4 of a concentration of 150-200 gms/litre may be " return acid " regenerated by subsequent zinc sulphate electrolysis. The acidity of the solution may be reduced prior to and after oxidizing with MnO 2 , by the addition of sintered zinc blende. The acid used for leaching the ferrites may have an H 2 SO 4 concentration of 300 gms/litre and a temperature of 90-95‹ C. may be maintained throughout the whole process. In a modification of the process the solution resulting from the leaching is increased in volume with neutral zinc sulphate solution and the resulting solution is subsequently neutralized with calcine.</p> |
