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A pilot-scale jet bubbling reactor for wet flue gas desulfurization with pyrolusite

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Journal of Environmental Sciences 2005年第5期17卷 827-831页

作者： SU Shi-jun ZHU Xiao-fan LIU Yong-jun JIANG Wen-ju JIN Yan National Engineering Research Center for Flue Gas Desulfurization Department of Environmental Science and Engineering Sichuan University Chengdu 610065 China

MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4· H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2^＋ extraction rate have been investigated, these factors include temperature of inlet gas flue, ration of liquid/solid mass flow rate（ L/S）, pyrolusite grade, and SO2 concentration in the inlet flue gas. In the meantime, the procedure of purification of absorption liquid was also discussed. Experiment results indicated that the increase of temperature from 30 to 70 K caused the increase of SO2 absorption efficiency from 81.4% to 91.2%. And when SO2 concentration in the inlet flue gas increased from 500 to 3000 ppm, SO2 absorption efficiency and Mn2^＋ extraction rate decreased from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of MnO2 in pyrolusite had a neglectable effect on SO2, absorption efficiency. Low L/S was good for both removal of SO2 and Mn2^＋ extraction. The absorption liquid was filtrated and purified to remove Si, Mg, Ca, Fe, Al and heavy metals, last product MnSO4· H2O was obtained which quality could reach China GB1622-86, the industry grade standards.

关键词： wet FGD jet bubbling reactor SO2 pyrolusite manganese sulfate

KINETICS OF LEACHING SPHALERITE WITH pyrolusite SIMULTANEOUSLY BY MICROWAVE IRRADIATION

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中国有色金属学会会刊：英文版 1997年第3期7卷 153-155页

作者： Peng, Jinhui Liu, Chunpeng Kunming Univ of Science & Technology Kunming China

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关键词： microwave irradiation sphalerite pyrolusite leaching kinetics

Galena-pyrolusite co-extraction in sodium chloride solution and its electrochemical analysis

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Transactions of Nonferrous Metals Society of China 2010年第5期20卷 897-902页

作者：龙怀中柴立元覃文庆 School of Metallurgical Science and Engineering Central South University School of Minerals Processing and Bioengineering Central South University

The co-extraction behavior of galena-pyrolusite in a sodium chloride solution and the electrochemical mechanism of this process were investigated,and some factors affecting the leaching rate of Pb and Mn were *** results show that all the factors such as the concentration of NaCl,HCl and pyrolusite ore,reaction time,temperature,adding times of HCl,affect the leaching rate of *** main affecting factors are the concentration of NaCl,reaction time and *** Tafel polarization curves and EIS plots of the galena and pyrolusite in the NaCl solution demonstrate that during the oxidation process of galena mineral electrode,film forms on the galena surface,which prevents galena from deeper ***,the film resistance can be greatly reduced in the presence of sodium chloride,thus promoting the reaction rate of galena.

关键词： galena pyrolusite co-extraction behavior electrochemical mechanism

Precise regulation of the phase transformation for pyrolusite during the reduction roasting process

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 81-90页

作者： Ruofeng Wang Peng Gao Shuai Yuan Yanjun Li Yingzhi Liu Cheng Huang School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China National-Local Joint Engineering Research Center of High-efficient Exploitation Technology for Refractory Iron Ore Resources Shenyang 110819China

The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore *** to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.

关键词： pyrolusite phase transformation reduction roasting microstructural evolution reaction mechanism

Fluidized roasting reduction kinetics of low-grade pyrolusite coupling with pretreatment of stone coal

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International Journal of Minerals,Metallurgy and Materials 2013年第3期20卷 221-227页

作者： Ya-li Feng Zhen-lei Cai Hao-ran Li Zhu-wei Du Xin-wei Liu School of Civil and Environmental Engineering University of Science and Technology Beijing State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

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.

关键词： pyrolusite ore roasting ore reduction fluidized beds kinetics stone coal

Reductive leaching of manganese from low-grade pyrolusite ore in sulfuric acid using pyrolysis-pretreated sawdust as a reductant

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 241-246页

作者： Ya-li Feng Shi-yuan Zhang Hao-ran Li School of Civil and Environmental Engineering University of Science and Technology Beijing National Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

Manganese （Mn） leaching and recovery from low-grade pyrolusite ore were studied using sulfiaric acid （H2SO4） as a leachant and pyrolysis-pretreated sawdust as a reductant. The effects of the dosage of pyrolysis-pretreated sawdust to pyrolusite ore, the concentration of sulfuric acid, the liquid/solid ratio, the leaching temperature, and the leaching time on manganese and iron leaching efficiencies were inves- tigated. Analysis of manganese and iron leaching efficiencies revealed that a high manganese leaching efficiency was achieved with low iron extraction. The optimal leaching efficiency was determined to be 20wt% pyrolysis-pretreated sawdust and 3.0 mol/L H2SO4 using a liq- uid/solid ratio of 6.0 mL/g for 90min at 90℃. Other low-grade pyrolusite ores were tested, and the results showed that they responded well with manganese leaching efficiencies greater than 98%.

关键词： manganese ore treatment pyrolusite sawdust pyrolysis leaching manganese

Study on Decoloration of Acidic Scarlet GR by pyrolusite Oxidation under an Acid Condition

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Acta Geologica Sinica(English Edition) 2006年第2期80卷 257-261页

作者： CHEN Gang QING Chengsong CHEN Tianhu LI Xiaoxuan SONG Yinxian PENG Shuchuan School of Natural Resources and Environmental Engineering Hefei University of Technology Hefei Anhui 230009 School of Chemical Engineering Hefei University of Technology Hefei Anhui 230009

Decoloration of acidic scarlet GR by pyrolusite is studied in this paper. The effects of pH in solution, dosage and granularity of pyrolusite, reaction temperature, and vibration speed on decoloration efficiency are discussed. According to experiment results, the decoloration efficiency may exceed 95% for 40 mg/L GR solution by pyrolusite, pH is most important among all factors which impact the decoloration of acidic scarlet GR. Dosage and granularity of pyrolusite, reaction temperature, and vibration speed have a little benitfit on decoloration. The high decoloration efficiency and low removal efficiency of COD as well as FT-IR spectra of products between pyrolusite and acidic scarlet GR indicate that acidic scarlet GR undergoes the redox reaction on the interface of mineral and its chromophore is oxidated and decolored, but it is not removed thoroughly by oxidation.

关键词： pyrolusite acid dye chemical oxidation environmental mineralogy

Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite

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Transactions of Nonferrous Metals Society of China 2017年第8期27卷 1831-1840页

作者： Shima RAHIMI Mehdi IRANNAJAD Akbar MEHDILO Department of Mining and Metallurgical Engineering Amirkabir University of Technology Tehran Iran

In the cationic flotation of pyrolusite using dodecyl ammine(DDA),the depressive effect of sodium carbonate andcalcium chloride on the calcite mineral was investigated systematically through flotation experiments,FTIR analysis,contact anglemeasurements and zeta potential *** microflotation experiments showed that both depressant agents decrease the flotationrecovery of calcite *** addition,sodium carbonate acts as activator agent for pyrolusite,and increases its *** experiments and contact angle measurements indicated that the selective depression effect of sodium carbonate on thecalcite mineral is more than that of calcium *** evidenced by zeta potential and FT-IR analysis,sodium carbonate decreasesthe negative charges on the surface of calcite mineral and subsequently reduces the adsorption of DDA collector through *** a pH of7.5,using2000g/t DDA and1500g/t sodium carbonate,a pyrolusite concentrate containing almost40%MnOwith71.5%recovery is achieved by carrying out the ore flotation experiments on the tabling pre-concentrate.

关键词： pyrolusite calcite flotation depressant sodium carbonate contact angle

Kinetics of Reductive Leaching of Low-grade pyrolusite with Molasses Alcohol Wastewater in H_2SO_4

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Chinese Journal of Chemical Engineering 2010年第5期18卷 730-735页

作者：粟海锋刘怀坤王凡吕小艳文衍宣 School of Chemistry and Chemical Engineering Guangxi University Nanning 530004 China Educational Administration Department Guangxi University Nannlng 530004 China

The kinetics of reductive leaching of manganese from low grade pyrolusite in dilute sulfuric acid in the presence of molasses alcohol wastewater was investigated. The shrinking core model was applied to quantify the effects of reaction parameters on leaching rate. The leaching rate increases with reaction temperature, concentrations of H 2 SO 4 and organic matter in molasses alcohol wastewater increase and ore particle size decreases. The leaching process follows the kinetics of a shrinking core model and the apparent activation energy is 57.5 kJ·mol –1 . The experimental results indicate a reaction order of 0.52 for H2SO4 concentration and 0.90 for chemical oxygen demand (COD) of molasses alcohol wastewater. It is concluded that the reductive leaching of pyrolusite with molasses alcohol wastewater is controlled by the diffusion through the ash/inert layer composed of the associated minerals.

关键词： pyrolusite molasses alcohol wastewater reductive leaching kinetics