极性矿物对纳米金的吸附实验

EXPERIMENTS ON THE ADSORPTION OF NANOMETER-SIZED GOLD ON POLAR MINERALS

纳米金通常带有负电荷．遇带正电荷的矿物，它将被吸附而沉淀。黄铁矿、黄铜矿、闪锌矿和α-石英是金矿中常见矿物，是载金矿物，也是极性矿物（半导体矿物，热电子物）。实验结果表明．在动态温度条件下矿物表面带有正负电荷。因此同种矿物能够相互吸附．纳米金被带正电荷的矿物吸附。在pH=4～7．5的条件下，黄铁矿、黄铜矿和闪锌矿对纳米金的吸附作用最强，吸附率为99％～100％．赤铜矿为25％～99％，α-石英的吸附率最低．只有0．2％～11．7％。在pH=11～13的条件下，N型黄铁矿和闪锌矿对纳米金的吸附作用最强，吸附率为100％，黄铜矿为83％，P型黄铁矿为63％。α-石英和赤铜矿的吸附率最低，α-石英为1．4％，赤铜矿为零。

Nanometer-sized gold is possessed of negative charge when it encounters with a mineral that is possessed of positive charge. nanometer-sized gold will be adsorbed. followed by deposition. Pyrite, chalcopyrite,sphalerite and a-quartz are common minerals in gold ore deposits and also are gold-carrier minerals and polar minerals (semiconducting minerals, thermoelectric minerals ). The experimental results show that mineral surface is possessed of negative or positive charge at dynamic temperature condition. Minerals (cuprite ) of the same kind can adsorb each other. Nanometer-sized gold will be adsorbed on minerals with positive charge. Minerals with negative charge cannot adsorb nanometer-sized gold. At PH=4-7. 5, pyrite, chalcopyrite and sphalerite are the best adsorbents of nanometer-sized gold, with the adsorption coefficients being as high as 99 % -100% and 25 % -99% (cuprite ). The adsorption coefficients of a-quartz are very low (0. 2- 11. 7). At PH =11 -13. N-pyrite and sphalerite are the best adsorbent of nanometersized gold, with the adsorption coefficients being as high as 100%, 83% (chalcopyrite) and 63% (p-pyrite). The adsorption coefficients are very low, with 1. 4% for a-quartz, and nearly 0% for cuprite.