Oxygen reduction at sulphide minerals .3. The effect of surface pre-treatment on the oxygen reduction at pyrite
Oxygen reduction at sulphide minerals .3. The effect of surface pre-treatment on the oxygen reduction at pyrite
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DOI：
10.1016/0301-7516(95)00100-x
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发表时间：
1996-06-01
影响因子：
--
通讯作者：
Broo, AE
中科院分区：
文献类型：
--
作者：
Ahlberg, E;Broo, AE
根据硫化矿物浮选的混合电位模型，氧还原构成了阴极反应。氧还原的机理和动力学在很大程度上取决于表面的性质。黄铁矿是一种较好的氧还原催化剂，反应通过形成可溶性过氧化氢进行，由于浮选矿浆中黄铁矿的表面与本体黄铁矿的组成不同，因此研究不同表面层对氧还原的影响是很重要的。本文用旋转环-盘电极技术研究了氧还原反应。进行三种不同的预处理以产生（i）氧化的表面，（ii）金属缺陷的表面和（iii）沉积硫的表面。结果表明，所有的预处理都能抑制氧还原。可溶性过氧化氢的量也发生变化，以黄铁矿>缺金属黄铁矿>氧化黄铁矿的顺序减少。对于硫覆盖的表面，不能检测到可溶性过氧化氢。并结合黄铁矿的浮选试验结果进行了讨论。
According to the mixed potential model for flotation of sulphide minerals, oxygen reduction constitute the cathodic reaction. The mechanism and kinetics of oxygen reduction is largely dependent on the properties of the surface. Pyrite is a relatively good catalyst for oxygen reduction and the reaction proceeds through the formation of soluble hydrogen peroxide.Since the surface of pyrite in the flotation pulp can differ from the composition of bulk pyrite it is important to investigate the influence of different surface layers on the oxygen reduction. In the present paper the oxygen reduction was studied using the rotating ring-disc electrode technique. Three different pre-treatments were made to produce (i) an oxidised surface, (ii) a metal deficient surface and (iii) a surface of deposited sulphur. The results show that for all the pre-treatments made the oxygen reduction will be inhibited. The amount of soluble hydrogen peroxide also changes, decreasing in the order pyrite > metal deficient pyrite > oxidised pyrite. For the sulphur covered surface, no soluble hydrogen peroxide could be detected. The results are discussed in the light of flotation of pyrite.