开放体系下方铅矿和黄铁矿之间原电池反应的实验研究

AN EXPERIMENTAL STUDY ON GALVANIC INTERACTION BETWEEN GALENA AND PYRITE IN AN OPEN SYSTEM

金属硫化物矿物之间的原电池反应对于酸性矿山排水的形成、硫化物矿床的次生富集作用、地球电化学勘探以及湿法冶金过程等都有很重要的影响。通过改变溶液中氧化剂组分F e3+的浓度、pH值、溶液的流动状况以及溶液的盐度(如N a2SO4的浓度),采用精密的电流计和电位计,对作为阳极的黄铁矿与作为阴极的方铅矿所形成的原电池反应的电流密度和整个原电池的混合电位进行研究,结果表明:溶液中[F e3+],pH值以及溶液的流动状况对黄铁矿和方铅矿之间原电池反应的影响很大,而溶液的盐度对反应的影响不是很显著。实验还发现,当黄铁矿电极表面存在微小裂纹时,其电极电位可降低至同条件下方铅矿的电极电位以下。这一实验结果在混合电位理论和Bu tler-V o lm er方程中得到了理论上的解释。

Galvanic interactions between sulfide minerals have very important influence on the formation of acid mine drainage,the supergene enrichment of sulfide ore deposits,the geoelectro-chemical exploration and the hydrometallurgical processes. By changing the concentration of Fe^3＋,the pH values ,status of the flowing of the solution and the solution salinity （such as the concentrations of Na2SO4） and monitoring the galvanic currents and potentials,experiments were conducted on the galvanic interaction between pyrite acting as the anode and galena acting as the cathode. The results indicate that the concentration of Fe^3＋ ,pH values and the flowing of the solution exhibit a great effect on the galvanic interaction of galena-pyrite couple,while the salinity of the solution has only a slight influence on the interaction. The experiments also reveal that in case cracks existed on the surface of pyrite electrode,the potential of pyrite decreases sharply and is even lower than that of galena under the same experimental condition. The experimental results were explained in terms of the Butler-Volume equation and the theory of mixed potential.