| 摘要 |
1,238,318. Silver dispersion. EASTMAN KODAK CO. 2 Oct., 1968 [2 Oct., 1967], No. 46676/68. Heading C1A. [Also in Division G2] A silver nuclei dispersion is prepared by adding (i) 40 ml. of 10% by weight aqueous sodium hydroxide to (ii) 140 ml. of 10% by weight aqueous dextrin and to this mixture adding with stirring (iii) 100 ml. of 10% by weight aqueous AgNO 3 at 40‹ C. Silver nuclei are produced due to the dextrin induced reduction of AgNO 3 to metallic silver. The electrostatic separation may be effected at 40-80‹ C. by allowing the ore to fall freely through a field of strength below 2000 V/cm., e.g. 800-1500 V/cm. The ore is thus separated from insoluble impurities, e.g. clay. |
