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A novel approach to with a preparing ultra-lightweight ceramsite large amount of fly ash

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Frontiers of Environmental Science & Engineering 2020年第4期14卷 77-87页

作者： Sen Liu Congren Yang Wei Liu Longsheng Yi wenqing qin School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

The disposal of fly ash has become a serious problem in China due to its rapid increase in volume in recent *** most common method of fly ash disposal is solidification-stabilization-landfill,and the most common reuse is low-value-added building materials.A novel processing method for preparing ultra-lightweight ceramsite with fly ash was *** results show that the optimal parameters for preparation of ultra-lightweight ceramsite are as follows:mass ratio of fly ash:kaolin:diatomite=80:15:5,preheating temperature of 800℃,preheating time of 5 min,sintering temperatiire of 1220℃,and sintering time of 10 *** expansion agent is perlite,at 10 wt.% ***,a ceramsite with bulk density of 340 kg/m3,particle density of 0.68 g/cm3,and cylinder compressive strength of 1.02 MPa was *** of its low density and high porosity,ultra-lightweight ceramsite has excellent thermal insulation performance,and its strength is generally low,so it is usually used in the production of thermal insulation concrete and its *** formation of a liquid-phase component on the surface,and generation of a gas phase inside ceramsite during the sintering process,make it possible to control the production of the suitable liquid phase and gas in this system,resulting in an optimization of the expansion behavior and microstructure of *** characteristics show the feasibility of industrial applications of fly ash for the production of ultralightweight ceramsite,which could not only produce economic benefits,but also conserve land resources and protect the environment.

关键词： Fly ash Ultra-lightweight ceramsite Expansion mechanism Sintering process

Flotation mechanism of octylic hydroxamic acid on diaspore

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Chinese Journal Of Geochemistry 2013年第2期32卷 191-194页

作者： LIU Sanjun qin wenqing PENG Tiefeng HU Yuehua School of Mineral Processing and Bioengineering Central South University School of Chemical Engineering The University of Queensland

Bauxite resources are widely spread in the earth. However, the effective utilization of this mineral is still under infant. The conventional collector for diaspore mineral is oleic acid. It has three main drawbacks which are highly insoluble, large dosages in bauxite flotation, and low selectivity, which hinder its application in industry. In this research, octylic hydroxamic acid was synthesized, and its collecting ability toward two major minerals in bauxite-diaspore and kaolinite was investigated. The collecting power of various reagents for diaspore are shown as follows: oleic acid

关键词：一水硬铝石异羟肟酸浮选机理辛酸铝土矿资源吸附能力硬水铝石电位测试

Application of EDTMPS as a novel calcite depressant in scheelite flotation

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International Journal of Mining Science and Technology 2023年第5期33卷 639-647页

作者： Fen Jiao Wei Li Xu Wang Congren Yang Zhengquan Zhang Liwen Fu wenqing qin School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

In this study, the innovative use of ethylenediamine tetramethylene phosphonic sodium(EDTMPS) as a calcite depressant in scheelite flotation was investigated by flotation experiments, and its selective depression mechanism was revealed by contact angle measurement, FTIR analysis, Zeta potential test and XPS analysis. The flotation experiment results showed that scheelite and calcite could be efficiently separated under the following conditions: pulp p H=9.5, Na OL concentration of 1.5×10^(-4)mol/L, EDTMPS concentration of 3.0×10^(-5)mol/L, a scheelite concentrate with WO3grade of 65.49%, recovery of 83.29%and separation efficiency of 65.29% could be obtained from the artificially mixed minerals. The analysis results of mineral surface properties demonstrated that EDTMPS was strongly adsorbed onto the calcite surface through the reaction between the phosphonate group and the calcium ions, which hindered Na OL adsorption and increased the hydrophilicity of calcite. However, EDTMPS had weak adsorption strength on the scheelite surface, which didn’t affect further adsorption of Na OL, hence, the scheelite remained hydrophobic. Consequently, the selective adsorption of EDTMPS on the two minerals’ surfaces increased a difference in wettability and thus enabling them to be separated by flotation. Finally, the mechanism model of this flotation separation process was established.

关键词： Ethylenediamine tetramethylene phosphonic sodium Scheelite Calcite Flotation Selective depression

Effect of depressants on flotation separation of magnesite from dolomite and calcite

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International Journal of Mining Science and Technology 2023年第1期33卷 83-91页

作者： wenqing qin Junjie Hu Hailing Zhu Fen Jiao Wenhao Jia Junwei Han Chen Chen School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

The flotation separation of magnesite from calcium-containing minerals has always been a difficult subject in minerals *** work studied the inhibition effects of carboxymethyl cellulose(CMC),sodium lignosulphonate,polyaspartic acid(PASP)and sodium silicate on flotation behaviors of magnesite,dolomite and calcite,providing guidance for the development of reagents in magnesite *** micro-flotation results showed that among these four depressants,sodium silicate presented the strongest selectivity due to the highest recovery difference,and the flotation separation of magnesite from dolomite and calcite could be achieved by using sodium silicate as the *** angle measurement indicated that the addition of sodium silicate caused the largest differences in surface wettability of the three minerals,which was in line with micro-flotation ***,zeta potential test,the Fourier transform infrared(FT-IR)spectroscopy and atomic force microscope(AFM)imaging were used to reveal the inhibition mechanism of sodium *** results indicated that the dominated component SiO(OH)3of sodium silicate could adsorb on minerals surfaces,and the adsorption of sodium silicate hardly affected the adsorption of NaOL on magnesite surface,but caused the reduction of NaOL adsorption on dolomite and calcite surfaces,thereby increasing the flotation selectivity.

关键词： Sodium silicate Magnesite Dolomite Calcite Flotation separation Inhibition

Uncovering the evolution of tin use in the United States and its implications

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Frontiers of Environmental Science & Engineering 2021年第6期15卷 281-291页

作者： Congren Yang Xianlai Zeng Haodong Li Zuyuan Tian Wei Liu wenqing qin Jinhui Li School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

Tin is of key importance to daily life and national security;it is considered an essential industrial *** United States(US)is the world’s largest economy and consumer of natural ***,the analysis of historical tin use in the US is helpful for understanding future tin use trends in the world as a whole and in developing *** series analysis,regression analysis with GDP or GDP/capita,and historical data fitted with logistic and Gompertz models are employed in this *** tin use in the US shows three stages-increase-constant-decrease,as GDP per capita has *** use in the US is negatively correlated with the GDP value added by the manufacturing sector,while the use of tin worldwide and in China continues to increase along with the GDP value added by the manufacturing *** a sigmoid curve can fit the US tin use data well,that use is not directly related to the limited tin reserves or ***,policies,economic restructuring,substitutions,new end-use markets,*** played key roles in the changing tin use *** work contributes to understanding future tin use at both the global and national levels:tin use will continue to increase with GDP at the global level,but use patterns of tin at the national level can be changed through human intervention.

关键词： Tin use GDP Curve fitting Logistic model Gompertz model

Alkyl dimethyl betaine activates the low-temperature collection capacity of sodium oleate for scheelite

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 71-80页

作者： Xu Wang Zhengquan Zhang Yanfang Cui Wei Li Congren Yang Hao Song wenqing qin Fen Jiao School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China College of Engineering Drexel UniversityPhiladelphiaPA 19102USA Luoyang Zhenbei Industry and Trade Co. Ltd.Luoyang 47100China

The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size *** flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.

关键词： scheelite betaine low temperature synergistic effect dispersion foamability

Investigation of condition-induced bubble size and distribution in electroflotation using a high-speed camera

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International Journal of Mining Science and Technology 2014年第1期24卷 7-12页

作者： Ren Liuyi Zhang Yimin qin wenqing Bao Shenxu Wang Peipei Yang Congren College of Resources and Environment Engineering Wuhan University of Technology School of Minerals Processing and Bioengineering Central South University

In the flotation process, bubble is a key factor in studying bubble-particle interaction and fine particle flo- tation. Knowledge on size distribution of bubbles in a flotation system is highly important. In this study, bubble distributions in different reagent concentrations, electrolyte concentrations, cathode apertures, and current densities in electroflotation are determined using a high-speed camera. Average bubble sizes under different conditions are calculated using Image-Pro@ Plus （Media Cybernetics@, MD, USA） and SigmaScan@ Pro （Systat Software, CA, USA） software. Results indicate that the average sizes of bubbles, which were generated through 38, 50, 74, 150, 250, 420, and 1000 μm cathode apertures, are 20.2, 29.5, 44.6, 59.2, 68.7, 78.5, and 88.8 μm, respectively. The optimal current density in electroflotation is 20 A/m2. Reagent and electrolyte concentrations, current density, and cathode aperture are important factors in controlling bubble size and nucleation. These factors also contribute to the control of fine- Particle flotation.

关键词： High-speed camera Bubble Electroflotation Fine particle Bubble production and control

Effect of sodium pyrophosphate on the flotation separation of chalcopyrite from galena

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International Journal of Mining Science and Technology 2012年第3期22卷 345-349页

作者： qin wenqing Wei Qian Jiao Fen Li Ning Wang Peipei Ke Lifang School of Mineral Processing and Bio-Engineering Central South University Changsha 410083 China

The effect of sodium pyrophosphate （SPH） on the separation of chalcopyrite from galena was examined through flotation, adsorption, electrokinetic studies and infrared spectral analysis. Differential flotation tests indicate that satisfactory separation can be achieved within the pH range from 2.5 to 6 using SPH to depress the galena, but not the chalcopyrite when O-isopropyl-N-ethyl thionocarbamate （IPETC） is used as the collector. The electrophoretic mohilities of both the minerals dramatically become negatively charged following SPH adsorption in the pH range from 2.5 to 12, The infrared spectral analysis suggests that chemical adsorption occurs on galena surface treated by SPH, indicating that a chelate complex has formed. At weakly acidic pH values, the adsorption density of IPETC onto galena is significantly reduced in the presence of SPH. However, the amount of IPETC adsorbed onto chalcopyrite almost remains at the same level. Since the observed adsorption density of IEPTC onto chalcopyrite is quite high compared to galena, the observed flotation results are explained. A possible mechanism for the interaction between the two sulphide minerals and SPH is discussed.

关键词： Sodium pyrophosphateChalcopyriteGalenaZeta potentialAdsorption density

Utilization of polysaccharides as depressants for the flotation separation of copper/lead concentrate

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International Journal of Mining Science and Technology 2013年第2期23卷 191-198页

作者： qin wenqing Wei Qian Jiao Fen Yang Congren Liu Ruizeng Wang Peipei Ke Lifang State Key Laboratory of Comprehensive Utilization of Low-Grade Ores School of Mineral Processing and Bio-Engineering Central South University

The interaction mechanism between dextrin and minerals has been investigated through micro-flotation, adsorption density measurements, Fourier transform infrared ray (FTIR) spectroscopic studies and dissolution tests. Dextrin shows a good depressing action towards galena but not chalcopyrite. FTIR spectroscopic studies indicate that dextrin chemically adsorbed on galena surface in alkaline pH range. Dissolution tests confirm leaching action of metal ions from chalcopyrite and galena surfaces, and dextrin-lead ion interaction. Adsorption measurements present that the higher adsorption density of O-isopropyl-N-ethyl thionocarbamate (IPETC) onto chalcopyrite than that onto galena, and IPETC adsorbed on galena decrease with increasing dextrin concentrations in the presence of dextrin, attesting the flotation results.

关键词： Polysaccharides Chalcopyrite Galena Depressant Depressing mechanism