Abstract The performance of native wheat starch (NWS), a hydrogen peroxide-oxidized wheat starch (Perox 3/30) and carboxymethyl cellulose (CMC) as copper-activated pyrite depressants are compared in lab-scale flotation trials. Both Perox 3/30 and CMC demonstrate similar and significantly better performance than NWS at dosages 100–300 g/t. At 700 g/t, both starches depressed essentially all of the copper-activated pyrite, whereas there was little change in recovery for CMC dosages above 300 g/t. The improved performance of Perox 3/30 and CMC at lower dosages appears to be associated with the presence of polymer structures with a hydrodynamic radius, Rh, of approximately 12–15 nm that are able to form a layer on the pyrite surface that is effective in preventing collector interaction. The continual decrease of flotation recovery with increasing NWS and Perox 3/30 dosage is likely associated with the greater molecular size of the starch polymers in that more hydroxyls can be associated with each adsorption site. The presence of branches on the starches that can extend from the pyrite surface plane may also improve interaction with the water phase near the surface, increase hydrophilicity and hence improve depression. Overall, the conformation of supramolecular and molecular structures of the polymers investigated here appear to be more influential than functional groups for depressing copper-activated pyrite.

中文翻译：

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天然淀粉、氧化淀粉和 CMC 作为铜活化黄铁矿抑制剂的比较

摘要 在实验室规模的浮选试验中比较了天然小麦淀粉 (NWS)、过氧化氢氧化小麦淀粉 (Perox 3/30) 和羧甲基纤维素 (CMC) 作为铜活化黄铁矿抑制剂的性能。Perox 3/30 和 CMC 在 100–300 g/t 的剂量下表现出与 NWS 相似且明显更好的性能。在 700 g/t 时，两种淀粉基本上抑制了所有铜活化的黄铁矿，而 CMC 剂量高于 300 g/t 时回收率几乎没有变化。Perox 3/30 和 CMC 在较低剂量下的改进性能似乎与流体动力学半径 Rh 约为 12-15 nm 的聚合物结构的存在有关，这些结构能够在黄铁矿表面形成有效的层防止收集器交互。随着 NWS 和 Perox 3/30 剂量的增加，浮选回收率的持续降低可能与淀粉聚合物的更大分子尺寸有关，因为每个吸附位点可以关联更多的羟基。淀粉上存在可从黄铁矿表面延伸的支链也可以改善与表面附近水相的相互作用，增加亲水性，从而改善凹陷。总的来说，这里研究的聚合物的超分子和分子结构的构象似乎比抑制铜活化黄铁矿的官能团更有影响。淀粉上存在可从黄铁矿表面延伸的支链也可以改善与表面附近水相的相互作用，增加亲水性，从而改善凹陷。总的来说，这里研究的聚合物的超分子和分子结构的构象似乎比抑制铜活化黄铁矿的官能团更有影响。淀粉上存在可从黄铁矿表面延伸的支链也可以改善与表面附近水相的相互作用，增加亲水性，从而改善凹陷。总的来说，这里研究的聚合物的超分子和分子结构的构象似乎比抑制铜活化黄铁矿的官能团更有影响。