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The raffinate in the extraction process contains plenty of acid and metallic ions, the dispose of which causes the resource loss and environmental pollution. The present study proposed an innovative way to solve this problem by using raffinate as the leaching agent in the copper leaching process. The effects of significant leaching parameters were investigated and optimized using the central composite design (CCD) of response surface methodology (RSM). A maximum leaching efficiency of 96.74 % can be obtained under the 53.22 Kg/t of initial acidity, 2.54 h of leaching time and 5.95 of liquid/solid ratio. In addition, the comparative features of samples before and after leaching process were analyzed by using the X-ray diffraction (XRD), sieving test, scanning electron microscope (SEM) and adsorption-desorption isotherms. We found that the majority of copper components have been removed from copper ores, causing the reduction of size distributions. Specifically, the content of

Iron ions activation of quartz is a tricky issue for efficiently sorting of target minerals in ferrous minerals flotation. The selection of an effective depressant is one of the most significant approaches to addressing this problem. In this study, the effects of calcium lignosulphonate (CLS), a widely studied novel depressant, on the flotation of Fe3+-activated quartz were investigated. The potential depression role of CLS in separating hematite from Fe3+-activated quartz in a sodium oleate (NaOl) flotation system was further explored. The flotation results indicated that the separation of hematite from quartz could be achieved by the selective depression of quartz in the presence of CLS. The results of zeta potential and spectroscopy analysis showed that CLS could absorb onto the surfaces of both hematite and Fe3+-activated quartz. The presence of CLS hindered the further adsorption of NaOl on quartz, whereas the NaOl adsorption onto hematite surfaces was limitedly affected. Compared with hematite, CLS might be more prone to react with the Fe sites on the surface of Fe3+-activated quartz, resulting in a relatively high final adsorption density on quartz surfaces, which was confirmed by X-ray photoelectron spectroscopy analysis and adsorption tests.

This paper studies the finite/fixed-time projective inner/outer synchronization of coupled memristor-based neural networks. An improved stability theory is proved to link finite-time and fixed-time synchronization only under the same one controller, which is more flexible and practical. Some sufficient conditions are acquired by means of Lyapunov methods, inequality techniques and designing appropriate controller to ensure finite/fixed-time projective inner/outer synchronization. The setting time of finite-time synchronization is discussed in detail and more accurate results are obtained. Some examples are presented to examine the feasibility and effectiveness of corresponding results.