Entity

Time filter

Source Type


Tu W.-M.,Wuhan University of Technology | Tu W.-M.,Hubei Key Laboratory of Mineral Resources Processing and Environment | Zou Q.,Wuhan University of Technology | Pan Q.,Wuhan University of Technology | And 2 more authors.
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2012

Sulfur-free expandable graphite was synthesized using the nitric acid as the oxidant and acetic acid as the inserting reagent, KMnO 4 as oxidant. The influence factors were discussed in detail, The optimized experimental conditions as follows: the raw flaky graphite (g): the nitric acid (mL): potassium permanganate (g)=1.0:2.0:0.15, the reaction time is 75 minutes at 20°C.The expanded volume of the sample preparing by this method is over 500. Compared with the existing technology, this method is the sulfur-free, the full expansion of low cost, easy to operate. Source


Bao S.,Wuhan University of Technology | Bao S.,Hubei Key Laboratory of Mineral Resources Processing and Environment | Liang L.,Wuhan University of Technology | Zhang Y.,Wuhan University of Technology | And 3 more authors.
Journal Wuhan University of Technology, Materials Science Edition | Year: 2015

The high calcium type stone coal from Hubei province was leached by water and dilute acid separately after being roasted with different dosage of NaCl. The water leaching rate of vanadium (WLRV) was low and only 26.8% of vanadium can be leached by water when 4% NaCl was added, but the acid leaching rate of vanadium (ALRV) was relatively high. Calcium in the high calcium type stone coal is greatly superfluous relative to vanadium, hence, the calcium reacts with vanadium to form Ca(VO3)2, Ca2V2O7 and Ca3(VO4)2 orderly during the stone coal roasting process and high temperature is beneficial to the reactions between calcium and vanadium, which was validated by simulated reactions between pure calcium carbonate and vanadium pentoxide. These calcium vanadates are all water insoluble but acid soluble and this causes the low WLRV and relatively high ALRV. After calcium removal by HCl, the WLRV is highly enhanced and reaches about 50% when only 2% NaCl was added. If the HCl content is too high, the stone coal is easily sintered and the formed glass structure can enwrap vanadium, which leads the WLRV to decline. Single water leaching process is not appropriate to extract vanadium from high calcium type stone coal. © 2015, Wuhan University of Technology and Springer-Verlag Berlin Heidelberg. Source


Bao S.,Wuhan University of Technology | Bao S.,Hubei Key Laboratory of Mineral Resources Processing and Environment | Tang Y.,Wuhan University of Technology | Zhang Y.,Wuhan University of Technology | And 3 more authors.
Chemical Engineering and Technology | Year: 2016

The recovery and separation of metals from aqueous solutions is one of the research hotspots in hydrometallurgy, environment protection, analytical chemistry, etc. Much attention has been paid to solvent-impregnated resins (SIRs) since these were firstly proposed for the extraction of metals. SIRs are characterized by high efficiency and selectivity, convenient preparation, and easy operation because they combine the unique advantages of solvent extraction and ion exchange. The preparation and features of SIRs are summarized and their applications in the extraction of various metals from solutions are reviewed. In addition, the equilibrium, thermodynamics, and sorption kinetics of the metals onto SIRs are elucidated in detail. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Source


Zhang Y.,Wuhan University of Technology | Zhang Y.,Hubei Key Laboratory of Mineral Resources Processing and Environment | Hu Y.,Wuhan University of Technology | Bao S.,Wuhan University of Technology | Bao S.,Hubei Key Laboratory of Mineral Resources Processing and Environment
Minerals Engineering | Year: 2012

The characteristics of the vanadium-bearing stone coal during chlorination roasting at different temperature were investigated. Chlorination roasting could promote the breakage of the structure of the main vanadium-bearing minerals, such as muscovite and illite, in the stone coal and more than 90% of the vanadium was lost after the sample was roasted in chlorine at 1000°C for 1 h. The volatile collected on the inner surface of the tube is mainly composed of chlorine, vanadium and other metals and it shows similar physical and chemical properties to vanadium oxytrichloride (VOCl 3). Hence, it is reasonable to predict that the vanadium was emitted as VOCl 3 in this process. The anhydrite gradually decomposed with the increasing temperature and the hematite in the samples reacted with the chlorine and disappeared above 700°C. Some new refractory mineral phases such as cordierite and hornblende can be found during the chlorination roasting. The decrease in the fluxing minerals and the formation of the refractory minerals can elevate the ash-fusion temperature of the stone coal and make it hard to sinter. © 2012 Elsevier Ltd. All rights reserved. Source


Han S.,Wuhan University of Technology | Zhang Y.,Wuhan University of Technology | Zhang Y.,Hubei Key Laboratory of Mineral Resources Processing and Environment | Bao S.,Wuhan University of Technology | Bao S.,Hubei Key Laboratory of Mineral Resources Processing and Environment
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2013

The sodium salt roasting-water leaching-dilute acid leaching experiment was adopted to extract vanadium from high calcium vanadium-bearing stone coal from Hubei. When the stone coal was roasted with 10% sodium chloride, at 850°C for 2 h, the water leaching rate of vanadium was only 14.28%, and the total leaching rate of vanadium was 69.14%. In order to improve the water leaching rate of vanadium, calcium removal and calcium stabilization before roasting were investigated. After calcium removal by 5% (volume fraction) of HCl and calcium stabilization by 2% (volume fraction) of H2SO4 separately, the decarbonized stone coal was roasted with sodium chloride under the same condition, as a result, the water leaching rate of vanadium reached 47.54% and 35.01%, and the total leaching rate of vanadium reached 66.16% and 60.81%, respectively. XRD results showed that the lime disappeared after calcium removal by HCl, therefore the water leaching rate of vanadium increased obviously and the optimal roasting temperature could be reduced. The results also showed that the lime disappeared after calcium stabilization by H2SO4, and the semi-hydrated gypsum started to emerge. The formation of CaSO4 could inhibit the formation of the water-insoluble substances, such as calcium vanadate, thus the water leaching rate of vanadium increased slightly, the sintering temperature could be raised and the sintering of roasting materials also could be lightened. However, the total leaching rate of vanadium decreased a little, and CaSO4 decomposed when adding a certain dosage of sodium chloride, which resulted in the water leaching rate of vanadium dropping. Under the same roasting conditions, the water leaching rate of vanadium of the calcium removal sample by HCl was higher than that of the calcium stabilization sample by H2SO4. Source

Discover hidden collaborations