In this paper, mineralogy, grain size, dissemination, textural consistency and mineral associations were determined for a commercially exploited porphyry copper ore using a Mineral Liberation Analyser (MLA). The ore was subjected to high power density microwave treatments in a single mode cavity at 15 kW and approximately 2 kW h/t. The untreated and microwave-treated samples were subsequently milled to two grind sizes near the nominal plant grind size and a size-by-liberation analysis performed. The analysis revealed that equivalent liberation could be obtained at a grind size approximately 50–60 μm coarser than the nominal plant grind due to the microwave treatment. Flotation testing indicated that an increase in copper recovery of approximately 1% could be achieved, or that a grind size increase of approximately 30 μm may potentially yield equivalent copper recovery due to the microwave-enhanced liberation observed. However, statistical analyses demonstrated that it is difficult to attain confidence in recovery increases of approximately 1% even when conducting batch flotation tests in triplicate. The ore under investigation had previously been shown to produce only modest average reductions in strength (∼8%) under similar microwave treatment conditions due to a prevalence of many unfavourable textures. However, the preferential association of copper minerals with a hard matrix mineral (quartz) and a hard microwave-absorbent mineral (pyrite) resulted in a significant change in liberation behaviour.
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机译：在本文中，使用矿物解放分析仪（MLA）确定了商业开发的斑岩铜矿的矿物学，晶粒度，散布，质地一致性和矿物缔合。在单模腔中以15 kW和约2 kW h / t对矿石进行高功率密度微波处理。随后将未经处理和经微波处理的样品研磨成接近标称植物研磨尺寸的两种研磨尺寸，并进行解放后尺寸分析。分析表明，由于采用微波处理，在比标称植物磨料粗约50–60μm的磨料尺寸下可以获得同等的游离度。浮选测试表明，由于观察到的微波增强的释放，可以实现大约1％的铜回收率的增加，或者大约30μm的研磨尺寸增加可能会产生等效的铜回收率。但是，统计分析表明，即使一式三份地进行批量浮选试验，也难以获得大约1％的回收率提高的信心。先前已证明，由于存在许多不利的组织结构，在相似的微波处理条件下，所研究的矿石只会使强度平均降低（约8％）。但是，铜矿物与硬质基质矿物（石英）和硬质微波吸收矿物（黄铁矿）的优先结合导致了释放行为的重大变化。
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