Surface oxidation is known to have a negative impact on the flotation performance of sulphide minerals. This is because severe oxidation makes it more difficult to process low-grade sulphide minerals, which reduces the recovery of valuable minerals during flotation. It may be possible to quantitatively correlate the rate/level of oxidation to oxidized sulphide ores using simple surface analytical techniques. This, if done well, could eliminate the need for numerous mineralogical tests, saving both time and money. This study investigated the EDTA Extraction Technique and Oxygen consumption factor (OCF) Technique as possible techniques to quantitatively describe oxidation levels in different ore types with different mineral compositions and grades. The aim was to determine if the changes in the surface character generated by oxidation are linked to a measurement obtained from the selected techniques. The techniques were validated on fresh ores of varying grades; high grade Cu (HG Cu) and Upper Group 2 (UG2). The two ores were then ground to generate varying particle size distributions and liberation profiles to study the link between oxidation, particle size and liberation. Based on ore type and sulphide liberation, the tests attempted to provide an indicator of feed grade and surface oxidation. Flotation is used as a diagnostic for the parameters mentioned. The results showed that (for Ore A/UG2) as particle size decreased (from grind size 40 %–75 μm), the recovery increased until it hit a maximum (grind size 60 %–75 μm) before monotonically declining (to grind size 80 %–75 μm). The OCF and EDTA values increased as the grind size became finer. The grind size 80 %–75 μm had suffered significantly more oxidation than the other grind sizes and this was indicated by the high OCF and the EDTA value. The liberated base metal sulphides (BMS) for Ore B (HG Cu) was generally consistent throughout the three grind sizes, however, the highest recovery was achieved by the grind size 80 %–75 μm (95.11 %), followed by grind sizes 60 %–75 μm and 40 %–75 μm respectively (92.25 % and 90.86 %). The recovery of this ore increases as the grind size becomes finer. Ore B demonstrated a direct correlation between the OCF and EDTA value for ore B increased as the grind size became finer, and the recovery. It is possible that the particles that were ground to achieve particle size 80 %–75 μm were at their most hydrophobic state, owing to the increased liberation of the BMS, particularly chalcopyrite.

中文翻译：

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使用简单的分析技术评估硫化矿石的表面氧化


已知表面氧化会对硫化物矿物的浮选性能产生负面影响。这是因为严重的氧化使得处理低品位硫化物矿物变得更加困难，从而降低了浮选过程中有价值矿物的回收率。使用简单的表面分析技术可以定量关联氧化硫化物矿石的氧化速率/水平。如果做得好，可以消除大量矿物学测试的需要，从而节省时间和金钱。本研究调查了 EDTA 提取技术和耗氧因子 (OCF) 技术，作为定量描述具有不同矿物成分和品位的不同矿石类型中氧化水平的可能技术。目的是确定氧化产生的表面特性的变化是否与通过所选技术获得的测量结果相关。这些技术在不同品位的新鲜矿石上得到了验证；高品位铜 (HG Cu) 和上族 2 (UG2)。然后将这两种矿石研磨以产生不同的粒度分布和释放曲线，以研究氧化、粒度和释放之间的联系。根据矿石类型和硫化物释放，测试试图提供进料品位和表面氧化的指标。浮选用作上述参数的诊断。结果表明（对于矿石 A/UG2），随着粒度减小（从研磨尺寸 40%–75μm），回收率增加，直到达到最大值（研磨尺寸 60%–75μm），然后单调下降（到研磨尺寸） 80%–75μm）。 OCF 和 EDTA 值随着研磨尺寸变细而增加。 80%–75 μm 的研磨尺寸比其他研磨尺寸遭受的氧化明显更多，这由高 OCF 和 EDTA 值表明。矿石 B (HG Cu) 的游离贱金属硫化物 (BMS) 在三种研磨尺寸中基本一致，但是，研磨尺寸 80%–75 μm (95.11%) 实现了最高回收率，其次是研磨尺寸 60分别为 %–75 μm 和 40%–75 μm（92.25% 和 90.86%）。随着研磨粒度变得更细，这种矿石的回收率增加。矿石 B 表明矿石 B 的 OCF 和 EDTA 值之间存在直接相关性，随着研磨粒度变细以及回收率的增加。由于 BMS（尤其是黄铜矿）的释放增加，研磨至粒径 80%–75 μm 的颗粒可能处于最疏水状态。