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Xie H.,Kunming University of Science and Technology | Xie H.,Guizhou University | Wang J.,Yunnan Metallurgy Group Parent Company | Lu H.,Guiyang Aluminium and Magnesium Design Institute Co. | Bao C.,Kunming Metallurgical Research Institute
Hydrometallurgy | Year: 2013

Pressure leaching of manganese smelter dust with air as pressurized gas in a sulfuric acid medium was investigated. Optimum operating parameters were established as follows: liquid-to-solid ratio (mL/g), 5:1; initial sulfuric acid concentration, 120 g/L; leaching temperature, 120 C; air pressure, 0.8 MPa; ore ratio (manganese smelter dust amount/pyrite amount), 1:0.5; leaching time, 2 h; and agitation speed, 500 r/min. Extraction rates of manganese and iron were obtained at 96.1% and 7%, respectively, under these conditions; and residual percentage of final acid was about 34.9%. Manganese can be effectively separated from impurities, such as iron, through leaching process. Leaching efficiency of manganese increased from 72.9% to 96.1%, whereas that of iron and the residual percentage of final acid both decreased with increase in leaching time from 40 min to 120 min. Pyrite was coated by elemental sulfur when temperature was higher than 119 C, resulting in its inability to act as a reductant and to react with manganese dioxide. Therefore, leaching temperature must be lower than 120 C. Pressure leaching technique for manganese smelter dust was proven to be effective and reliable. © 2013 Elsevier B.V. Source


Feng Q.,Kunming University of Science and Technology | Wen S.,Kunming University of Science and Technology | Zhao W.,Kunming Metallurgical Research Institute | Deng J.,Kunming University of Science and Technology | Xian Y.,Kunming University of Science and Technology
Applied Surface Science | Year: 2016

The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na2S, and the increase in the Na2S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na2S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na2S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite. © 2015 Elsevier B.V. All rights reserved. Source


Cui Q.-X.,Yunnan Xinli Nonferrous Metals Co. | Xie H.-B.,Yunnan Xinli Nonferrous Metals Co. | Mao Y.-P.,Kunming Metallurgical Research Institute
Yejin Fenxi/Metallurgical Analysis | Year: 2014

A simple and accurate determination method of trace and ultratrace arsenic in zirconium oxychloride (ZrOCl2.8H2O) was proposed. According to the content of arsenic in sample, less than 10 g of sample was put into a simple distillator. After adding certain amount of hydrochloric acid (containing little potassium bromide and ferrous sulfate), the sample was heated and decomposed. The distilled arsenic trichloride was absorbed with cold water. After dilution to constant volume, the content of arsenic in solution was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) under selected instrumental conditions. The response intensity of arsenic was in direct ratio to its concentration in range of 0.0-10.0μg/mL. The correlation coefficient of calibration curve (r) was higher than 0.999 9. The recoveries of standard addition were between 99% and 112%. The relative standard deviation (RSD, n=5) was in range of 0.5%-2.0%. The proposed method was applied to the determination of trace and ultratrace arsenic in zirconium oxychloride. The found results were consistent with those obtained by catalytic polarography or atomic fluorescence spectrometry. ©, 2014, Central Iron and Steel Research Institute. All right reserved. Source


Han F.,Kunming University of Science and Technology | Lei T.,Kunming Metallurgy College | Zhou L.,Kunming Metallurgical Research Institute | Huang S.,Kunming University of Science and Technology | Lu G.,Kunming University of Science and Technology
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2012

The adequate carbon should be fed as reductant in order to achieve qualified titanium slag, and deoxidized the highoxide to lowoxide. The domestic first 30 MVA DC arc furnace of a company in Yunnan province obtained the favorable slag by controlling the ratio of anthracite to ilmenite (AIR), in the case of certain energy input and stable component of ilmenite. The ilmenite and anthracite were put into DC furnace through hollow graphite electrode, meanwhile it was needed to control temperature between 1973 K and 2023 K, 15 MVA of input power, 0.1~0.33 mm of partical size of ilmenite, the ratio of anthracite partical size range of 5~25 mm were more than 85%. Theoretically, deoxidizing 1t ilmenite would produce 526 kg titanium slag and 368 kg iron, and Output/Input rate was about 89.4%, the theory AIR was about 7.895%. Calculated on mass balance, the mean AIR during the smelting period was 12.228%, and output/input rate was 81.317%. With the short of anthracite, the oxygen of FeO in ilmenite would be easy to dissociate and combine with carbon; in this case, the reduction reaction of FeO would be prior to TiO 2. On the other hand, with more carbon, the carbon will be used for deoxidizing the oxide that are difficult to reducte, for example, MgO, CaO, MnO and so on, and the reduction of FeO would be restrained. AIR also effects on the fluidity of molten slag and freeze lining. The content of TiO 2 in the titanium slag increased to more than 89% from 82% in the trial by modulating the AIR. Source


Jiang Y.-J.,Pioneer Corporation | Cui Q.-X.,Pioneer Corporation | Mao Y.-P.,Kunming Metallurgical Research Institute
Yejin Fenxi/Metallurgical Analysis | Year: 2015

The determination of trace copper and vanadium in titanium dioxide sample by inductively coupled plasma atomic emission spectrometry (ICP-AES) was interfered with the titanium matrix. The titanium matrix was precipitated and separated by diammonium hydrogen phosphate [(NH4)2HPO4]. Then, the content of trace copper and vanadium in titanium dioxide sample was determined by ICP-AES. The sample dissolution method, the precipitation conditions of titanium with (NH4)2HPO4 and the determination conditions of ICP-AES were investigated. The results showed that the titanium in 0.1 g of titanium dioxide sample could be fully react with (NH4)2HPO4 to form Ti(HPO4)2 precipitate in ammonium sulfate and sulfuric acid medium after heating in boiling bath for 3-5 min. The determination results were stable under the selected instrumental conditions with Cu 327.4 nm and V 292.4 nm as analytical spectral line. The detection limit of copper and vanadium was 0.001 μg/mL and 0.000 7 μg/mL, respectively. The proposed method was applied to determination of copper and vanadium in titanium dioxide actual samples. The relative standard deviation (RSD) was not more than 1.2%, and the recoveries were between 90% and 117%. The proposed method was applicable for the routine analysis of titanium dioxide. ©, 2015, Central Iron and Steel Research Institute. All right reserved. Source

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