The development of a sulfidisation technique to restore the flotation of oxidised pentlandite
The development of a sulfidisation technique to restore the flotation of oxidised pentlandite
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DOI：
10.1016/j.mineng.2007.04.012
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发表时间：
2007-08
影响因子：
4.8
通讯作者：
A. Newell;D. Bradshaw
中科院分区：
文献类型：
--
作者：
A. Newell;D. Bradshaw
热氧化的恩科马蒂块状硫化矿的硫化成功地恢复了氧化硫化物矿物（包括镍黄铁矿）的浮选回收率。然而，作为单一矿物，氧化镍黄铁矿不易硫化，XPS 分析未能识别出任何硫化的表面物质。提出了氧化镍黄铁矿的硫化机制，其中来自氧化 Nkomati 矿物表面的铁和铜物质通过沉淀过程或吸附的铁和铜氢氧化物的转化在氧化镍黄铁矿表面上形成硫化物，并随后赋予可浮性。为了评估这一建议，研究了氧化镍黄铁矿作为单一矿物的硫化过程中贱金属离子的作用。发现在硫化过程中添加铁可有效提高随后的浮选回收率，并且在硫化物离子电极电势为-650mV（-315 SHE）时达到最大值。虽然这与氧化恩科马蒂矿石硫化过程中发现的镍黄铁矿相对应，但硫化镍黄铁矿作为单一矿物漂浮得更慢。铁比铜更有效，很可能是因为铁的浓度明显更高。在较低硫氢化物浓度下，硫化电势的重要性与氢硫化物离子的可用性有关，而在较高硫化电势下，它与吸附的贱金属氢硫化物离子络合物的抑制作用有关。提出了一种技术，通过在硫化过程中添加贱金属离子，改善了难以硫化的矿物（例如氧化镍黄铁矿）的浮选回收率。
The sulfidisation of a thermally oxidised Nkomati massive sulfide ore was successful in restoring the flotation recoveries of the oxidised sulfide minerals including pentlandite. As a single mineral, however, oxidised pentlandite was not readily sulfidised and XPS analyses failed to identify any sulfidised surface species. A sulfidisation mechanism for oxidised pentlandite is proposed whereby iron and copper species from the oxidised Nkomati mineral surfaces form sulfides on the oxidised pentlandite surfaces, either through a precipitation process or the conversion of adsorbed iron and copper hydroxides, and subsequently confer floatability. To evaluate this proposal, the role of base-metal ions during the sulfidisation process was studied for oxidised pentlandite as a single mineral. The addition of iron during sulfidisation was found to be effective in improving the subsequent flotation recovery and was a maximum after sulfidisation at a sulfide ion electrode potential of −650mV (−315 SHE). While this corresponded to that found for pentlandite during the sulfidisation of oxidised Nkomati ores, the sulfidised pentlandite floated more slowly as a single mineral. Iron was more effective than copper, most likely due to a significantly higher concentration. The significance of the sulfidisation potential at lower hydrosulfide concentrations is related to hydrosulfide ion availability while at higher sulfidisation potentials, it is associated with the depressive effect of adsorbed base-metal hydrosulfide ion complexes. A technique is presented whereby base-metal ions additions during sulfidisation improved the flotation recovery of a difficult to sulfidise mineral species, such as oxidised pentlandite.