期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Kinetics of rare earth leaching from roasted ore of bastnaesite with sulfuric acid 被引量:10
1
作者 冯兴亮 龙志奇 +3 位作者 崔大立 王良士 黄小卫 张国成 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第3期849-854,共6页
Sulfuric acid leaching process was applied to extracting rare earth(RE) from roasted ore of Dechang bastnaesite in Sichuan,China.The effect of particle size,stirring speed,sulfuric acid concentration and leaching te... Sulfuric acid leaching process was applied to extracting rare earth(RE) from roasted ore of Dechang bastnaesite in Sichuan,China.The effect of particle size,stirring speed,sulfuric acid concentration and leaching temperature on RE extraction efficiency was investigated,and the leaching kinetics of RE was analyzed.Under selected leaching conditions,including particle size(0.074-0.100 mm),sulfuric acid concentration 1.50 mol/L,mass ratio of liquid to solid 8 and stirring speed 500 r/min,the leaching kinetics analysis shows that the reaction rate of leaching process is controlled by diffusion through the product/ash layer which can be described by the shrinking-core model,and the calculated activation energy of 9.977 kJ/mol is characteristic for a diffusion-controlled process. 展开更多
关键词 BASTNAESITE rare earth roasting ore LEACHING KINETICS
下载PDF
Upgrading and dephosphorization of Western Australian iron ore using reduction roasting by adding sodium carbonate 被引量:12
2
作者 De-qing Zhu Tie-jun Chun +2 位作者 Jian Pan Li-ming Lu Zhen He 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第6期505-513,共9页
The technology of direct reduction by adding sodium carbonate (Na2CO3) and magnetic separation was developed to treat Western Australian high phosphorus iron ore. The iron ore and reduced product were investigated b... The technology of direct reduction by adding sodium carbonate (Na2CO3) and magnetic separation was developed to treat Western Australian high phosphorus iron ore. The iron ore and reduced product were investigated by optical microscopy and scanning electron microscopy. It is found that phosphorus exists within limonite in the form of solid solution, which cannot be removed through traditional ways. During reduction roasting, Na2CO3 reacts with gangue minerals (SiO2 and A1203), forming aluminum silicate-containing phosphorus and damaging the ore structure, which promotes the separation between iron and phosphorus during magnetic separation. Meanwhile, Na2CO3 also improves the growth of iron grains, increasing the iron grade and iron recovery. The iron concentrate, assaying 94.12wt% Fe and 0.07wt% P at the iron recovery of 96.83% and the dephosphorization rate of 74.08%, is obtained under the optimum conditions. The final product (metal iron powder) after briquetting can be used as the burden for steelmaking by an alactrie a.re furnace to rer)la,ce scrar) steel. 展开更多
关键词 iron ore reduction sodium carbonate ore roasting magnetic separation phosphorus removal
下载PDF
Thermodynamics and kinetics of extracting zinc from zinc oxide ore by the ammonium sulfate roasting method 被引量:15
3
作者 Yi Sun Xiao-yi Shen Yu-chun Zhai 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第5期467-475,共9页
Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by (NH4)2SO4 roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the z... Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by (NH4)2SO4 roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the zinc oxide ore and (NH4)2SO4 in a temperature range of 573-723 K. The effects of reaction temperature and particle size on the extraction rate of zinc were also examined. It is found that a surface chemical reaction is the rate-controlling step in roasting kinetics. The calculated activation energy of this process is about 45.57 kJ/mol, and the kinetic model can be expressed as follows: 1 - (1 - α)1/3 = 30.85 exp(-45.57/RT)·t. An extraction ratio of zinc as high as 92% could be achieved under the optimum conditions. 展开更多
关键词 zinc metallurgy extraction ammonium sulfate ore roasting THERMODYNAMICS KINETICS
下载PDF
Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore 被引量:2
4
作者 Nurul A.Yunus Mohd H.Ani +4 位作者 Hamzah M.Salleh Rusila Z.A.Rashid Tomohiro Akiyama Hadi Purwanto Nur E.F.Othman 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第4期326-330,共5页
Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bi... Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the mag-netization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was par-tially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic proper-ties 展开更多
关键词 iron ores ore reduction ore roasting BIO-CHAR magnetic properties
下载PDF
Manganese extraction from high-iron-content manganese oxide ores by selective reduction roasting-acid leaching process using black charcoal as reductant 被引量:10
5
作者 张元波 赵熠 +3 位作者 游志雄 段道显 李光辉 姜涛 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2515-2520,共6页
Reduction roasting-acid leaching process was utilized to process high-iron-content manganese oxide ore using black charcoal as reductant. The results indicate that, compared with the traditional reductant of anthracit... Reduction roasting-acid leaching process was utilized to process high-iron-content manganese oxide ore using black charcoal as reductant. The results indicate that, compared with the traditional reductant of anthracite, higher manganese extraction efficiency is achieved at lower roasting temperature and shorter residence time. The effects of roasting parameters on the leaching efficiency of Mn and Fe were studied, and the optimal parameters are determined as follows: roasting temperature is 650 °C, residence time is 40 min, and black charcoal dosage is 10%(mass fraction). Under these conditions, the leaching efficiency of Mn reaches 82.37% while that of Fe is controlled below 7%. XRD results show that a majority of MnO2 and Fe2O3 in the raw ore are reduced to MnO and Fe3O4, respectively. 展开更多
关键词 manganese ore reduction roasting acid leaching black charcoal
下载PDF
Effects of the mineral phase and valence of vanadium on vanadium extraction from stone coal 被引量:29
6
作者 Yang-jia Hu Yi-min Zhang +1 位作者 Shen-xu Bao Tao Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第10期893-898,共6页
The influence of roasting on the leaching rate and valence of vanadium was evaluated during vanadium extraction from stone coal. Vanadium in stone coal is hard to be leached and the leaching rate is less than 10% when... The influence of roasting on the leaching rate and valence of vanadium was evaluated during vanadium extraction from stone coal. Vanadium in stone coal is hard to be leached and the leaching rate is less than 10% when the raw ore is leached by 4 moUL H2SO4 at 90℃ for 2 h. After the sample is roasted at 900℃ for 2 h, the leaching rate of vanadium reaches the maximum, and more than 70% of vanadium can be leached. The crystal of vanadium-bearing mica minerals decomposes and the Content of V(V) increases with the rise of roasting temperature from 600 to 900℃, therefore the leaching rate of vanadium increases significantly with the decomposition of the mica minerals. Some new phases, anorthite for example, form when the roasting temperature reaches 1000℃. A part of vanadium may be enwrapped in the sintered materials and newly formed phases, which may impede the oxidation of low valent vanadium and make the leaching rate of vanadium drop dramatically. The leaching rate of vanadium is not only determined by the valence state of vanadium but also controlled by the decomposition of vanadium-bearing minerals and the existence state of vanadium to a large extent. 展开更多
关键词 vanadium metallurgy stone coal LEACHING ore roasting
下载PDF
Fluidized roasting reduction kinetics of low-grade pyrolusite coupling with pretreatment of stone coal 被引量:9
7
作者 Ya-li Feng Zhen-lei Cai +2 位作者 Hao-ran Li Zhu-wei Du Xin-wei Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第3期221-227,共7页
Based on the fluidized roasting reduction technology of low-grade pyrolusite coupling with pretreatment of stone coal, the manganese reduction efficiency was investigated and technical conditions were optimized. It is... Based on the fluidized roasting reduction technology of low-grade pyrolusite coupling with pretreatment of stone coal, the manganese reduction efficiency was investigated and technical conditions were optimized. It is found that the optimum manganese reduction efficiency can be up to 98.97% under the conditions that the mass ratio of stone coal to pyrolusite is 3:1, the roasting temperature of stone coal is 1000℃, the roasting temperature of pyrolusite is 800℃, and the roasting time is 2 h. Other low-grade pyrolusite ores in China from Guangxi, Hunan, and Guizhou Provinces were tested and all these minerals responded well, giving -99% manganese reduction efficiency. Meanwhile, the reduction kinetic model has been established. It is confirmed that the reduction process is controlled by the interface chemical reaction. The apparent activation energy is 36.397 kJ/mol. 展开更多
关键词 PYROLUSITE ore roasting ore reduction fluidized beds KINETICS stone coal
下载PDF
Thermodynamics and kinetics of alumina extraction from fly ash using an ammonium hydrogen sulfate roasting method 被引量:13
8
作者 Ruo-chao Wang Yu-chun Zhai Zhi-qiang Ning 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第2期144-149,共6页
A novel method was developed for extracting alumina (Al2O3) from fly ash using an ammonium hydrogen sulfate (NH4HSO4) roasting process, and the thermodynamics and kinetics of this method were investigated. The the... A novel method was developed for extracting alumina (Al2O3) from fly ash using an ammonium hydrogen sulfate (NH4HSO4) roasting process, and the thermodynamics and kinetics of this method were investigated. The thermodynamic results were verified experi-mentally. Thermodynamic calculations show that mullite present in the fly ash can react with NH4HSO4 in the 298-723 K range. Process op-timization reveals that the extraction rate can reach up to 90.95% when the fly ash reacts with NH4HSO4 at a 1:8 mole ratio of Al2O3/NH4HSO4 at 673 K for 60 min. Kinetic analysis indicates that the NH4HSO4 roasting process follows the shrinking unreacted core model, and inner diffusion through the product layer is the rate-controlling step. The activation energy is calculated to be 16.627 kJ/mol;and the kinetic equation can be expressed as 1-(2/3)α-(1-α)2/3=0.0374t exp[-16627/(RT)], whereαis the extraction rate and t is the roasting temperature. 展开更多
关键词 ammonium hydrogen sulfate ore roasting fly ash ALUMINA THERMODYNAMICS KINETICS
下载PDF
Active and passive behaviors of gold in cyanide solutions 被引量:1
9
作者 Ahmet Deniz BAS Fariba SAFIZADEH +2 位作者 Wei ZHANG Edward GHALI Yeonuk CHOI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3442-3453,共12页
Active and passive behaviors of pure gold(Au) and roasted gold ore(RGO) electrodes were investigated at 25 °C in de-aerated agitated cyanide media.Cyclic voltammetry and potentiodynamic polarization with agit... Active and passive behaviors of pure gold(Au) and roasted gold ore(RGO) electrodes were investigated at 25 °C in de-aerated agitated cyanide media.Cyclic voltammetry and potentiodynamic polarization with agitation at 100 r/min in 0.04 mol/L NaCN solution showed different peak positions and current densities.Potentiodynamic tests illustrate that the peak current densities increase greatly with increasing the cyanide concentration.Increasing the pH value from 10 to 11 resultes in a great decrease of current density,while it increases noticeably by decreasing the agitation from 100 to 60 r/min.In the presence of oxygen,Au and RGO electrodes show different characteristics of peak positions and corrosion rates.The potentiostatic studies show that increasing the potential from 1 to 1.4 V at pH value of 11 results in an 80% decrease of current density while decreasing the pH value from 11 to 10 at 1 V gives a 1.7 fold increase of current density,possibly due to more effective passive layer.Following polarization,electrochemical noise measurements(ENM) during decay periods show that Au results in more passive states at high potentials,showing pitting corrosion.The ENM results show that this technique can be a promising tool for a better understanding of gold leaching.The XPS studies prove the presence of passive oxides. 展开更多
关键词 pure gold roasted gold ore CYANIDE PASSIVATION electrochemical noise
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部