Xanthate-functional temperature-responsive polymers as selective flocculants and collectors for fines recovery
Xanthate-functional temperature-responsive polymers as selective flocculants and collectors for fines recovery
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DOI：
10.1016/j.mineng.2016.05.013
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发表时间：
2016-10
影响因子：
4.8
通讯作者：
Wei Sung Ng;L. Connal;E. Forbes;G. Franks
中科院分区：
文献类型：
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作者：
Wei Sung Ng;L. Connal;E. Forbes;G. Franks
研究了一种提高浮选过程中细粒回收率的新方法，即使用含有n -异丙基丙烯酰胺（PNIPAM）和黄药官能性的温度响应共聚物聚（n -异丙基丙烯酰胺-co-乙基甲基丙烯酸黄药）（PNEXMA）。在较低的临界溶液温度（LCST）以上，聚合物既可以作为捕收剂又可以作为絮凝剂，形成有价值的细粒的疏水聚集体，可以通过浮选进行选矿。通过吸附、接触角和聚集研究的初步筛选，以及随后的浮选试验，对PNEXMA用于硫化微粒浮选的可行性进行了评估。研究在低于和高于最低温度的温度下进行，并将结果与工业捕收剂戊基黄药钾（PAX）进行比较。吸附等温线表明黄铜矿表面具有很强的聚合物亲和性。在PNEXMA和PAX的存在下，石英表面的接触角保持相对亲水性不变，而黄铜矿表面的接触角在60°以上时变为疏水性，与PAX相当。聚合物对黄铜矿也有温度响应的可逆絮凝作用，而对PAX和石英没有反应。对黄铜矿的浮选研究证实，PNEXMA能够作为选择性捕收剂，其性能与PAX相当。然而，在- 20 μm细粒中，PAX的回收率没有提高，这是由于在当前的工作中使用了完全解放的合成饲料，导致PAX的细粒回收率很高，而PAX在实际的地面矿物中通常没有。
A novel method to improve the recovery of fines in the flotation process involving the use of a temperature-responsive copolymer poly(N-isopropyl acrylamide-co-ethyl xanthate methacrylate) (PNEXMA) incorporating poly(N-isopropyl acrylamide) (PNIPAM) and xanthate functionality has been investigated. Above a lower critical solution temperature (LCST), the polymer functions as both a collector and flocculant, forming hydrophobic aggregates of the valuable fines that are amenable to beneficiation by flotation. The viability of using PNEXMA for the flotation of sulfide fines has been evaluated based on initial screening with adsorption, contact angle and aggregation studies followed by flotation tests. The studies were conducted at both temperatures below and above the LCST, and the results were compared with an industrial collector, potassium amyl xanthate (PAX). Adsorption isotherms indicate a strong polymer affinity for chalcopyrite surfaces. The quartz contact angles were found to remain relatively hydrophilic and unchanged in the presence of the PNEXMA and PAX, while the chalcopyrite surface turned hydrophobic with contact angles above 60°, comparable to PAX. Temperature-responsive reversible flocculation was also observed with the polymer on chalcopyrite, while no response was found with PAX or with quartz. Flotation studies with chalcopyrite confirmed that PNEXMA is able to act as a selective collector, with performances on par with PAX. However, no recovery improvement over PAX was observed in the −20 μm fines fraction, which was attributed to the use of fully-liberated synthetic feed in the current work resulting in high fines recoveries with PAX not usually found in actual ground mineral ores.