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Fe_(3)O_(4)对黄铜矿在酸性硫酸铁溶液中铜溶解氧化还原反应的影响
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作者 kolela j nyembwe Elvis FOSSO-KANKEU +3 位作者 Frans WAANDERS Martin MKANDAWIRE Didier K nyembwe Bhekie B MAMBA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第6期1965-1975,共11页
由于钝化层的形成,黄铜矿(CuFeS_(2))在氧化条件下浸出通常具有溶解速率缓慢的特点。为了将黄铜矿浸出过程中的钝化效应降至最低并提高铜的回收率,研究了CuFeS_(2)在不同pH值(1.0、1.5和1.8)和温度(25和50℃)条件下浸出时,向Fe_(2)(SO_(... 由于钝化层的形成,黄铜矿(CuFeS_(2))在氧化条件下浸出通常具有溶解速率缓慢的特点。为了将黄铜矿浸出过程中的钝化效应降至最低并提高铜的回收率,研究了CuFeS_(2)在不同pH值(1.0、1.5和1.8)和温度(25和50℃)条件下浸出时,向Fe_(2)(SO_(4))_(3)−H_(2)SO_(4)浸出剂中添加磁铁矿(Fe_(3)O_(4))对铜溶解速率的影响。结果表明,溶液pH值、电位和温度在溶解过程中起着关键作用。在pH 1.8、50℃和400 mV的条件下,Fe_(3)O_(4)−CuFeS_(2)混合体系中铜的回收率达到最大值(70%),而未添加Fe_(3)O_(4)时,CuFeS_(2)中铜的回收率较低(48%)。添加Fe_(3)O_(4)有助于维持较高的氧化还原值。添加Fe_(3)O_(4)还使活化能从79.04 kJ/mol降低到53.69 kJ/mol。这表明,当Fe_(3)O_(4)存在时,由于形成了更易溶解的中间体斑铜矿(Cu_(5)FeS_(4))和辉铜矿(Cu_(2)S),CuFeS_(2)更易被氧化。两种溶解过程都受到矿物表面的化学控制。此外,对浸出残渣的矿物学分析表明,当无Fe_(3)O_(4)存在时,作为表面钝化物的黄钾铁矾浓度较高。因此,添加Fe_(3)O_(4)减少了钝化层的形成,提升了铜的回收率。 展开更多
关键词 黄铜矿 溶解 磁铁矿 电偶 钝化
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Structural, compositional and mineralogical characterization of carbonatitic copper sulfide: Run of mine, concentrate and tailings 被引量:5
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作者 kolela j nyembwe Elvis Fosso-Kankeu +1 位作者 Frans Waanders Kasongo D nyembwe 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第2期143-151,共9页
The aim of this study was to determine the structural, compositional, and mineralogical composition of carbonatitic copper sulfide concentrator plant streams. Three samples, each from a different stream(run of mine(RO... The aim of this study was to determine the structural, compositional, and mineralogical composition of carbonatitic copper sulfide concentrator plant streams. Three samples, each from a different stream(run of mine(ROM), concentrate, and tailings) of a copper concentrator were characterized using various techniques, including stereomicroscopy, X-ray fluorescence, X-ray diffraction, Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy(SEM) in conjunction with energy-dispersive X-ray spectroscopy(EDS), and optical microscopy. The results reveal that each stream possesses its own unique compositional features. Carbonate minerals associated with calcite and dolomite, followed by quartz, remain the major minerals in both the ROM and tails streams. In the ROM stream, chalcopyrite appears to occur as veins within the carbonatite-hosting ore body. Mineral phase mutation was discovered in the tails stream because magnetite formerly identified in the ROM as the primary iron oxide had evolved into hematite. This metamorphosis was likely promoted by the concentration process. The concentration process was effective, upgrading the chalcopyrite content from 2 wt% in the ROM stream to 58 wt% in the concentrate stream; it was accompanied by bornite(4 wt%), anilite(3 wt%), and digenite(2.5 wt%). In addition, the concentrate stream exhibited properties distinctive from those of the other streams. The FTIR analysis showed the existence of a sulfide group related to the chalcopyrite mineral. Free chalcopyrite grains were observed in the concentrate by SEM analysis, and their mineral presence was supported by the EDS analysis results. All characterization techniques corresponded well with each other regarding the structure, chemistry, and composition of the samples. 展开更多
关键词 CHALCOPYRITE MINERAL characterization phase MUTATION CONCENTRATE STREAMS
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pH-dependent leaching mechanism of carbonatitic chalcopyrite in ferric sulfate solution 被引量:3
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作者 kolela j nyembwe Elvis FOSSO-KANKEU +1 位作者 Frans WAANDERS Martin MKANDAWIRE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第7期2139-2152,共14页
The dissolution of a carbonatitic chalcopyrite(CuFeS2)was studied in H_(2)SO_(4)−Fe_(2)(SO_(4))_(3)−FeSO_(4)−H_(2)O at varying pH values(0.5−2.5)and 25℃ for 12 h.Experiments were conducted with a size fraction of 53... The dissolution of a carbonatitic chalcopyrite(CuFeS2)was studied in H_(2)SO_(4)−Fe_(2)(SO_(4))_(3)−FeSO_(4)−H_(2)O at varying pH values(0.5−2.5)and 25℃ for 12 h.Experiments were conducted with a size fraction of 53−75μm.Low Cu recoveries,below 15%,were observed in all pH regimes.The results from the XRD,SEM−EDS,and optical microscopic(OM)analyses of the residues indicated that the dissolution proceeded through the formation of transient phases.Cu_(3.39)Fe_(0.61)S_(4) and Cu_(2)S were the intermediate phases at pH 0.5 and 1.0,respectively,whereas Cu_(5)FeS_(4) was the major mineral at pH 1.5 and 1.8.The thermodynamic modelling predicted the sequential formation of CuFeS_(2)→Cu_(5)FeS_(4)→Cu_(2)S→CuS.The soluble intermediates were Cu_(5)FeS_(4) and Cu2S,whilst,CuS and Cu_(3.39)Fe_(0.61)S_(4) were the refractory phases,supporting their cumulating behaviour throughout the dissolution.The obtained results suggest that the formation of CuS and Cu_(3.39)Fe_(0.61)S_(4) could contribute to the passive film formed during CuFeS_(2) leaching. 展开更多
关键词 CHALCOPYRITE CARBONATITE chemical leaching leaching mechanism intermediate phase thermodynamic behavior
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