期刊文献+
共找到84篇文章
< 1 2 5 >
每页显示 20 50 100
Analysis of the Characteristics of Materials Obtained by Recycling Scrap Metal in Guinea
1
作者 Alpha Issa Diallo Jean Ahmed Kourouma +1 位作者 Adama Moussa Sakho Alexandre Lucien Richard 《材料科学与工程(中英文A版)》 2024年第1期1-10,共10页
The aim of this study was to determine the quality of rebar produced from recycled scrap metal collected throughout the country,and imported rebar sold in the Republic of Guinea.To do this,the samples were subjected t... The aim of this study was to determine the quality of rebar produced from recycled scrap metal collected throughout the country,and imported rebar sold in the Republic of Guinea.To do this,the samples were subjected to various mechanical tests involving traction,bending and microscopic analysis.In the Lambanyi and Casse Sonfonia samples,all the tensile strength values for diameters 12,14 and 16 were above 550 MPa.Conversely,the iron samples from Baillobaye and the 10 mm diameters of the samples from Casse Sonfonio and Lambanyi have less appreciable values.The limits of elasticity were determined.The various values found vary more or less from the conventional yield strength of the NF A35-016 reference supplied by CBITEC,which is 500 MPa.Microscopic analysis gives us an insight into the internal structure of the iron samples used.This study may provide the company and the vendors with an alternative for their improvements. 展开更多
关键词 Steel in construction recycled scrap strength test TRACTION bending.
下载PDF
Co-pyrolysis of soybean soapstock with iron slag/aluminum scrap,and characterization and analysis of their products 被引量:1
2
作者 Xueguang Li Mengyan Yu +8 位作者 Changfa Zhang Xiangtong Li Guangqing Liu Jianjun Dai Chunbao Zhou Yang Liu Jie Fu Yingwen Zhang Bang Yao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第1期25-36,共12页
Soybean soapstock(SS) is one of the main solid wastes produced in the refinery of edible oil processing. In this study, the co-pyrolysis of SS with iron slag(IS) and aluminum scrap(AS) was carried out in a tubular fur... Soybean soapstock(SS) is one of the main solid wastes produced in the refinery of edible oil processing. In this study, the co-pyrolysis of SS with iron slag(IS) and aluminum scrap(AS) was carried out in a tubular furnace. The gas, liquid and solid products were characterized and the char yield decreased with increasing IS/AS ratio. IS and AS can improve the gas yield, and when the ratio of SS/IS was 1:0.25, the total pyrolysis gas and hydrogen contents were significantly increased. The content of oxygen compounds in pyrolysis oil decreased during co-pyrolysis, while AS promoted the content of polycyclic aromatic hydrocarbons in pyrolysis oil. The co-pyrolysis reaction can be divided into four stages, the mass loss rate reaches the maximum at the third stage(390–575 ℃). The molar ratio of H/C was lower for pyrolysis,indicating good stability of pyrolysis char owing to the high degree of carbonization and aromaticity.The possible co-pyrolysis reaction mechanism was explored. 展开更多
关键词 PYROLYSIS Soybean soapstock Iron slag Aluminum scrap Adsorption CATALYST
下载PDF
Radiological Doses and Risk Assessment of NORM Scrap Metal by Using RESRAD-RECYCLE Computer Code
3
作者 Amaal A. Tawfik Eman M. Ahmed 《Open Journal of Modelling and Simulation》 2014年第2期34-42,共9页
In this work the radiological dose and risks resulting from recycling of radioactive contaminated NORM scrap metal that produced from one of oil and gas production companies in Egypt, were determined by using RESRAD-R... In this work the radiological dose and risks resulting from recycling of radioactive contaminated NORM scrap metal that produced from one of oil and gas production companies in Egypt, were determined by using RESRAD-RECYCLE computer code. Two scenarios were used: the first was the workers’ scenario, while the second was end-use product scenario. Workers’ scenario was used in this study for evaluating the dose and risk to workers who process recycled materials. This scenario focused on the transport of radioactive NORM scrap metal from the place of origin to the smelter (scrap delivery step). Scenarios for six different workers were included under the scrap delivery step: two workers scrap cutter, two workers scrap loader, and two workers scrap truck driver. The values for each scenario were specified on the basis of processing 200 tons of NORM scrap metal. Because these operations occur before melting of the metal, mass and radionuclide partitioning factors were not applied in the scrap metal delivery step. The radionuclide concentration of the NORM scrap metal was used directly in the dose calculation. The maximum doses received from direct external exposure to all radio nuclides during cutter/sorter, scrap truck driver and unloading of scrap metals were 2.14E-04, 1.4E-06 and 1.86E-05 (mSv) respectively. The excess cancer risks for all radio nuclides during cutter/sorter of scrap metals reached 1.25E-07. Radiation exposures incurred by the scrap unloaders and scrap cutters/sorters were greater than those incurred by the other workers for their closer exposure distances and longer time. 展开更多
关键词 NORM scrap Metals Risk ASSESSMENT Dose ASSESSMENT RESRAD-RECYCLE RADIOACTIVE Waste
下载PDF
Discussion on Abnormal Corrosion and Material Selection of Hot Iron Ladles with Steel Scrap Addition
4
作者 XU Guotao ZHAO Yuan +4 位作者 WU Jie ZHANG Honglei LIU Li ZHANG Yanwen ZHOU Wangzhi 《China's Refractories》 CAS 2023年第1期1-5,共5页
The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbid... The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbide-carbon bricks for the ladle bottom,those for the ladle wall have more pyrophyllite and the Al2O3 content of 36.32 mass%;their bulk density,apparent porosity and cold compressive strength are lower than the requirement of industry standard;they have poor anti-oxidation performance and are oxidized to form a porous layer during service,which loosens the brick lining structure thus leading to fracture,local wear and structural damage of bricks;(2)without preheating,steel scraps are not completely melted,resulting in slag or steel attachment at the mouth or the bottom of ladles thus increasing damage of ladles;(3)and the residual bricks react with the attached slag to form low melting point phases affecting their hot properties.The refractories for the lining of hot iron ladles must be improved in combination with process changes,not entirely by raw materials replacement to reduce costs. 展开更多
关键词 steel scraps hot iron ladles REFRACTORIES alumina-silicon carbide-carbon bricksot
下载PDF
Study of the Characteristics of Large-Diameter Iron Bars Obtained by Rolling at the ODHAV Foundry in the Republic of Guinea
5
作者 Alpha Issa Diallo Jean Ahmadou Kourouma +3 位作者 Adama Moussa Sakho Younoussa Moussa Baldé Mamadou Madaniou Sow Alexandre Lucien Richard 《Journal of Materials Science and Chemical Engineering》 2024年第6期43-54,共12页
This work consists of evaluating the quality of the mechanical parameters of large-diameter steels, i.e. 20, 25, 28 and 32, through a process of recycling scrap metal that fills garages, rubbish dumps, gutters and oth... This work consists of evaluating the quality of the mechanical parameters of large-diameter steels, i.e. 20, 25, 28 and 32, through a process of recycling scrap metal that fills garages, rubbish dumps, gutters and other abandoned sites, as well as imported concrete reinforcing steel sold in the Republic of Guinea. To carry out this important work, a number of mechanical tensile and bending tests and a microscopic analysis combining two devices, an electron microscope and a photographic camera, were carried out. The samples were taken from sampling areas in the major communes of Conakry, namely: Casse Sonfonia, Matoto and Kagbélen. The tensile strength values of the large dimensions 20, 25, 28 and 32 are given in the tables. 展开更多
关键词 Recycled scrap Large Diameter ROLLING Tensile Testing BENDING
下载PDF
Derived oil production by catalytic pyrolysis of scrap tires 被引量:8
6
作者 李伟 黄传峰 +8 位作者 李大鹏 霍鹏举 王明峰 韩磊 陈刚 李慧慧 李晓宏 王永娟 王孟艳 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第4期526-532,共7页
Scrap tires were pyrolyzed in a continuously stirred batch reactor in the presence and absence of catalysts. The maximum yield of derived oil was up to 55.65 wt%at the optimum temperature, 500 °C. The catalytic p... Scrap tires were pyrolyzed in a continuously stirred batch reactor in the presence and absence of catalysts. The maximum yield of derived oil was up to 55.65 wt%at the optimum temperature, 500 °C. The catalytic pyrolysis was performed using 1.0 wt%(on a scrap tire weight basis) of catalysts based on ZSM‐5, USY,β, SAPO‐11, and ZSM‐22. The oil products were characterized using simula‐tion distillation, elemental analysis, and gas chromatography‐mass spectrometry. The results show that using a catalyst can increase the conversion of scrap tires to gas and decrease char by‐products;the yield of derived oil remains unchanged or a little lower. The oils derived from catalytic pyrolysis had H/C ratios of 1.55–1.65 and contained approximately 70–75 wt%light oil, 0.3–0.58 wt%S and 0.78–1.0 wt%N. Catalysts with high acid strengths and appropriate pore sizes, such as ZSM‐5, USY,β, and SAPO‐11, increased the amount of single‐ring aromatics in the light‐middle‐fraction oil to 45 wt%. The derived oil can therefore be used as a petrochemical feedstock for producing high‐value‐added chemical products or fuel oil. 展开更多
关键词 scrap tire Catalytic pyrolysis Derived oil AROMATIC
下载PDF
Effect of extrusion ratio on microstructure and mechanical properties of AZ91D magnesium alloy recycled from scraps by hot extrusion 被引量:6
7
作者 胡茂良 吉泽升 陈晓瑜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第6期987-991,共5页
A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and... A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Microstructural observations revealed that all the recycled specimens consisted of fine grains due to the dynamic recrystallization.The main strengthening mechanism of the recycled specimen was grain refinement strengthening and homogeneous distribution of oxide precipitates.The interfaces of individual scraps of extruded materials were not identified when the scraps were extruded with the extrusion ratio of 40-1.Oxidation layers of the scraps were broken into pieces by high compressive and shear forces under the extrusion ratio of 40-1.The ultimate tensile strength and elongation to failure increased with increasing the extrusion ratio.Recycled specimens with the extrusion ratio of 40:1 showed higher ultimate tensile strength of 342.61 MPa and higher elongation to failure of 11.32%,compared with those of the cast specimen. 展开更多
关键词 extrusion ratio AZ91D magnesium alloy scraps mechanical property MICROSTRUCTURE
下载PDF
Simulation on scrap melting behavior and carbon diffusion under natural convection 被引量:6
8
作者 Ming Gao Jin-tao Gao +1 位作者 Yan-ling Zhang Shu-feng Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第3期380-389,共10页
A 3D model applying temperature-and carbon concentration-dependent material properties was developed to describe the scrap melting behavior and carbon diffusion under natural convection.Simulated results agreed reason... A 3D model applying temperature-and carbon concentration-dependent material properties was developed to describe the scrap melting behavior and carbon diffusion under natural convection.Simulated results agreed reasonably well with experimental ones.Scrap melting was subdivided into four stages:formation of a solidified layer,rapid melting of the solidified layer,carburization,and carburization+normal melting.The carburization stage could not be ignored at low temperature because the carburization time for the sample investigated was 214 s at 1573 K compared to 12 s at 1723 K.The thickness of the boundary layer with significant concentration difference at 1573 K increased from 130μm at 5 s to 140μm at 60 s.The maximum velocity caused by natural convection decreased from 0.029 m·s^(−1)at 5 s to 0.009 m·s^(−1)at 634 s because the differences in temperature and density between the molten metal and scrap decreased with time. 展开更多
关键词 scrap melting natural convection carbon diffusion numerical simulation electron probe micro-analyzer
下载PDF
Crushing performance and resource characteristicof printed circuit board scrap 被引量:7
9
作者 王晖 顾帼华 戚云峰 《Journal of Central South University of Technology》 EI 2005年第5期552-555,共4页
The crushing performance of printed circuit board (PCB) was studied on several crushers. The results show that PCB is a material which is difficult to crush. The crushing performance of PCB with disk crusher, especial... The crushing performance of printed circuit board (PCB) was studied on several crushers. The results show that PCB is a material which is difficult to crush. The crushing performance of PCB with disk crusher, especially vibration grinding, which has cut or impact action, excels that of jaw crusher or roller crusher. The PCB scrap is worthwhile to recycle using variety of modern characterization methods. When compared with natural resources, this material stream remains a rich precious metal and nonferrous metals. In PCB scrap, metals account for 47% of the total material composition, in which there exists 19.66% copper, 11.47% iron, 3.93% lead, 300 g/t gold and 510 kg/t silver, etc. In addition, the PCB scrap contains 27% of plastics and 26% of refractory oxides. 展开更多
关键词 electronic scrap printed circuit board CRUSHING RECYCLING
下载PDF
Effect of Mn addition and refining process on Fe reduction of Mg−Mn alloys made from magnesium scrap 被引量:5
10
作者 Dong-dong GU Jia-wen WANG +1 位作者 Yu-bin CHEN Jian PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第11期2941-2951,共11页
The Fe reduction,microstructure evolution and corrosion susceptibility of Mg−Mn alloys made from magnesium scrap refining with Mn addition were investigated.The results show that significant Fe content change occurs d... The Fe reduction,microstructure evolution and corrosion susceptibility of Mg−Mn alloys made from magnesium scrap refining with Mn addition were investigated.The results show that significant Fe content change occurs during near-solid-melt treatment(NSMT)process even in the absence of Mn,because of the high saturation of Fe in the melt.Furthermore,in the NSMT process,even a small amount of Mn addition can lead to a sharp deposition of Mn atoms.The NSMT process can increase the growth rate of the Fe-rich particles,and then accelerate their sinking movement.Nevertheless,the addition of Mn hinders the coarsening process of Fe-rich particles.Besides,the corrosion susceptibility of the alloys is mainly affected by the solubility of Fe,which can be significantly reduced by Mn addition.Moreover,the presence of more Fe-rich particles does not necessarily increase the corrosion susceptibility of the alloy.Consequently,in the refining process of Mg−Mn alloys made from magnesium scrap,on the basis of NSMT process and adding an appropriate Mn content(about 0.5 wt.%),the purity of the melt can be improved,thereby obtaining an alloy with excellent corrosion resistance. 展开更多
关键词 Fe reduction melt refining process magnesium scrap Fe-rich particle corrosion susceptibility
下载PDF
Recycle for Sludge Scrap of Nd-Fe-B Sintered Magnet as Isotropic Bonded Magnet 被引量:4
11
作者 Masahiro Itoh Masahiro Masuda +1 位作者 Shunji Suzuki Ken-ichi Machida 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第1期168-171,共4页
The reduction diffusion method was performed for the sludge scrap of Nd-Fe-B sintered magnets with adding Ca metal to recover the oxidized Nd-Fe-B phase. After washing the resultant powders to remove Ca metal componen... The reduction diffusion method was performed for the sludge scrap of Nd-Fe-B sintered magnets with adding Ca metal to recover the oxidized Nd-Fe-B phase. After washing the resultant powders to remove Ca metal component, the powders obtained were recycled as an isotropic magnetic powder by the melt spinning method. The magnetic properties of powders as recycled were inferior, especially for the coercivity value, due to the deletion of rare earth metals during the washing process. The adjustment of metal composition, i.e., the addition of Nd metal, at the melt spinning process improved the magnetic properties to be B r=~0.75 T, H cj=~0.93 mA·m -1, and (BH) max=~91 kJ·m -3. The magnetic properties of the bonded magnets prepared from the composition-adjusted powders were B r=~0.66 T, H cj=~0.92 mA·m -1, and (BH) max=~70 kJ·m -3, which are approximately comparable to the commercially available MQPB boned one (B r=~0.73 T, H cj=~0.79 mA·m -1, and (BH) max=~86 kJ·m -3). 展开更多
关键词 Nd-Fe-B sintered magnet recycling isotropic Nd-Fe-B bonded magnet melt-spinning method sludge scrap rare earths
下载PDF
RECOVERY OF CADMIUM AND NICKEL FROM SCRAP Ni-Cd BATTERIES 被引量:3
12
作者 J.X. Zhu1), B. Yu2), J.H. Li1) and Y.F. Nie1) 1) Department of Environmental Engineering, Tsinghua University, Beijing 100084, China 2) Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2001年第4期303-312,共10页
Several typical methods for the recovery of Ni-Cd batteries are described in detail. Based on the comparison between the hydrometallurgical process and the pyrometallurgical process, the latter is selected as the suit... Several typical methods for the recovery of Ni-Cd batteries are described in detail. Based on the comparison between the hydrometallurgical process and the pyrometallurgical process, the latter is selected as the suitable method for recycling Ni-Cd batteries in China. 展开更多
关键词 CADMIUM NICKEL RECOVERY scrap metal
下载PDF
Microstructure and Mechanical Properties of AZ91D Magnesium Alloy Recycled from Scraps by Hot-press/extrusion 被引量:3
13
作者 Mao-Liang Hu Ze-Sheng Ji +1 位作者 Xiao-Yu Chen Qu-Dong Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第1期115-120,共6页
A large number of scraps are produced in the fabrication process of magnesium alloy products. It is necessary to recycle these scraps for the development and scale application of magnesium alloys. In this research,a m... A large number of scraps are produced in the fabrication process of magnesium alloy products. It is necessary to recycle these scraps for the development and scale application of magnesium alloys. In this research,a method for recycling AZ91D magnesium alloy scraps fabricated by hot-press / extrusion was studied. Mechanical properties and microstructure of the recycled specimens were investigated. Microstructural analyses were performed by using the techniques of optical microscopy and scanning electron microscopy. Microstructural observations reveal that the recycled specimens consisted of fine grains when adopting the extrusion temperature of 400- 450 ℃,the extrusion ratio of( 25- 100) ∶ 1 and the extrusion rate of 0. 10- 0. 20 mm / s. Ultimate tensile strength and elongation to failure increased with the increase of the extrusion temperature,the extrusion ratio and the extrusion rate,respectively. Recycled specimens reached the highest ultimate tensile strength of average 361. 47 MPa and the highest elongation to failure of average 11. 55% when adopting the hot-press,the extrusion temperature of 400± 5 ℃,the extrusion ratio of 100 ∶ 1 and the extrusion rate of 0. 15 mm / s. The shape of bonding interface was tightly relation with the ultimate tensile strength. When the bonding interface formed continuous curves,the ultimate tensile strength decreased almost linearly with increasing the average width of the bonding interface. When the bonding interface formed discontinuous curves,the ultimate tensile strength increased almost linearly with the increase the proportion of the fine bonding length accounting for the measured interface length. Ultimate tensile strength of the recycled specimens could be calculated by using the forecastable equation. 展开更多
关键词 scraps magnesium alloy mechanical property bonding interface
下载PDF
Reductive denitrification of nitrate by scrap iron filings 被引量:2
14
作者 郝志伟 徐新华 汪大翚 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE EI CAS CSCD 2005年第3期182-186,共5页
Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certai... Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed. 展开更多
关键词 DENITRIFICATION scrap iron filings (SIF) Zero-valent iron NITRATE MECHANISM
下载PDF
Recycling of minute metal scraps by semisolid processing:Manufacturing of design materials 被引量:2
15
作者 S.SUGIYAMA T.MER A J.YANAGIMOTO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第9期1567-1571,共5页
As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal sha... As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal shape, was manufactured using minute metal scraps.Similarly, a design material with an intended color pattern for each metal, such as red copper in a white aluminum matrix, resembling grainlike wood, was manufactured by mixing two or more types of minute metal scrap.In addition, secondary design materials, which have engraved patterns on the surface of the target metal made by an electric discharge machine using the above primary design material as an electrode, were manufactured. 展开更多
关键词 semisolid processing minute metal scraps RECYCLING design material
下载PDF
Effect of additives on anode passivation in direct electrolysis process of copper–nickel based alloy scraps 被引量:2
16
作者 LI Lei LI Hong-juan +1 位作者 QIU Shi-wei WANG Hua 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期754-763,共10页
Effects of nickel component,thiourea,glue and chloride ions and their interactions on the passivation of copper–nickel based alloy scrap anodes were investigated by combining conventional electrochemical techniques.R... Effects of nickel component,thiourea,glue and chloride ions and their interactions on the passivation of copper–nickel based alloy scrap anodes were investigated by combining conventional electrochemical techniques.Results obtained from chronopotentiometry and linear voltammetry curves showed that the Ni component made electrochemical stability of the anode strong and difficult to be corroded,caused by the adsorption of generated Cu2O,NiO or copper powder to the anode surface.The Ni2+reducing Cu2+to Cu+or copper powder aggravated the anode passivation.In a certain range of the glue concentration≤8×10–6 or thiourea concentration≤4×10–6,the increase of glue or thiourea concentration increases the anode passivation time.Over this range,glue and thiourea played an adverse effect.The increase of chloride ions concentration led to the increase in passivation time. 展开更多
关键词 copper–nickel based alloy scrap direct electrolysis nickel component anode passivation additive
下载PDF
Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge powder and sodium chloride 被引量:2
17
作者 Sandeep Kumar Jena Jogeshwar Sahu +2 位作者 Geetikamayee Padhy Swagatika Mohanty Ajit Dash 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第9期1203-1215,共13页
The present paper reports the effective utilization of marble sludge powder(MSP)for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method.Characterization studies indica... The present paper reports the effective utilization of marble sludge powder(MSP)for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method.Characterization studies indicated the presence of dolomite as the major mineral phase in MSP,whereas muscovite and quartz were observed in the mica sample.The acid leaching studies suggest a maximum of 22%potash recovery under conditions:4 M H2SO4 acid,particle size of^100μm,stirring speed of 600 r/min,leaching temperature of 75℃,and leaching time of 90 min.The chlorination roasting-water leaching process was adopted to achieve the lowest level of 80%-90%potash recovery.The optimum conditions for the recovery of^93%potash from mica(~8.6wt%K2O)requires 900℃ roasting temperature,30 min roasting time,and 1:1:0.75 mass ratio of mica:MSP:NaCl.The roasting temperature and amount of NaCl are found to be the most important factors for the recovery process.The reaction mechanism suggests the formation of different mineral phases,including sylvite(KCl),wollastonite,kyanite,and enstatite,during roasting,which were confirmed by X-ray diffraction(XRD)analyses and scanning electron microscopy(SEM)morphologies.The MSP-blended NaCl additive is more effective for potash recovery compared with the other reported commercial roasting additives. 展开更多
关键词 potash recovery mica scrap marble sludge powder chlorination roasting water leaching
下载PDF
The Dynamic Experiment on Treating Acid Mine Drainage with Iron Scrap and Sulfate Reducing Bacteria Using Biomass Materials as Carbon Source 被引量:2
18
作者 Xianjun Wang Junzhen Di +7 位作者 Yanrong Dong Yu Yang Bing Liang Fankang Meng Tingting Wang Wenbo An Zengxin Li Jianzhi Guo 《Journal of Renewable Materials》 SCIE EI 2021年第1期163-177,共15页
The study is aimed at the problem of high content of Cr^(6+),Cr^(3+)and SO_(4)^(2-)is high and low pH value in acid mine drainage(AMD).Moreover,treatment of AMD by sulfate reducing bacteria(SRB)requires the addition o... The study is aimed at the problem of high content of Cr^(6+),Cr^(3+)and SO_(4)^(2-)is high and low pH value in acid mine drainage(AMD).Moreover,treatment of AMD by sulfate reducing bacteria(SRB)requires the addition of carbon source,while the treating effectiveness is not good enough on its own.The sugarcane slag,the corn cob and the sunflower straw were selected as the SRB carbon source cooperating with iron scrap to construct the dynamic columns 1,2 and 3.The mechanism of removing Cr^(6+),Cr^(3+),SO_(4)^(2-)and H+and the regularity of sustained release of carbon source and TFe release was studied in AMD.The removal efficiency of heavy metal ions,the ability of sustained release of carbon source,and the ability of adjusting acid by the three dynamic columns were compared.The result shows that the average removal rates of Cr^(6+),Cr^(3+)and SO_(4)^(2-)in effluent of dynamic column 1,filled by sugarcane slag,iron scrap and SRB,were 96.9%,67.1%and 54.3%.The average release of TFe and chemical oxygen demand(COD)were 4.4 and 287.3 mg/L.Its average pH was 6.98.Compared with the performance of dynamic columns 1,2 and 3,dynamic column 1 performed best in removing Cr^(6+),Cr^(3+)and SO_(4)^(2-)from AMD and controlling the release of COD and TFe,adjusting the pH of the solution.The study is of significance in treatment of AMD by taking for biomass materials as SRB carbon source in cooperation with iron scrap. 展开更多
关键词 Biomass material sulfate reducing bacteria acid mine drainage iron scrap
下载PDF
Effect of the Proportion of Bamboo Scraps on the Properties of Bamboo Scraps/Magnesium Oxychloride Composites 被引量:1
19
作者 Long Zheng Yiqiang Wu +3 位作者 Shu Wang Guoan Sheng Baorong Sun Yingfeng Zuo 《Journal of Renewable Materials》 SCIE EI 2021年第10期1729-1739,共11页
This study was designed to solve the problem of large waste volume from bamboo processing residues in recent years.Using magnesium oxychloride(MO)cementitious material as the main material and bamboo residue(BR)as the... This study was designed to solve the problem of large waste volume from bamboo processing residues in recent years.Using magnesium oxychloride(MO)cementitious material as the main material and bamboo residue(BR)as the reinforcing material,a BR/MO composite material was prepared.The effects of BR amount on the molding properties,mechanical strength,and water resistance of BR/MO composites were examined and discussed.Scanning electron microscopy(SEM),X-ray diffractometry(XRD),and thermogravimetric analysis were used to characterize composite microscopic morphology,crystalline structure,and heat resistance.The results showed that,when the BR content was 1.00%(by wt),the flowability of MO paste was beneficial to composite molding.Composite mechanical properties and water resistance were greatly affected by BR addition.When the BR content was 1.00%,composite compressive and bending strengths and softening coefficient all reached maximum values.Meanwhile,increases in water absorption by 24 h and decreases of contact angle were small.These results suggested that,when the BR content was 1.00%,composite mechanical properties and water resistance were the best and the mechanical strength also improved with extended composite storage time.SEM analysis indicated that BR played the role of a reinforcing phase in MO matrices.However,when the BR content exceeded 1.00%,interfacial bonding between BR and MO became less.XRD analysis showed that,with 1.00%BR content,composites showed more 5-phase crystals with high strength.This further explained the reason why this composite’s mechanical properties were the best and the heat resistance not deteriorated due to BR,which was easily decomposed. 展开更多
关键词 Bamboo scraps magnesium oxychloride cementation mechanical properties water resistance interface bonding crystal structure
下载PDF
Recovering Scrap Anode Copper Using Reactive Electrodialysis 被引量:1
20
作者 Gerardo Cifuentes José Hernández Nicolás Guajardo 《American Journal of Analytical Chemistry》 2014年第15期1020-1027,共8页
Despite functioning without major operational problems—copper electro-refining does not allow complete use of copper anodes, peaking at 85% of the copper anode in weight. Consequently, the remaining 15% of scrap copp... Despite functioning without major operational problems—copper electro-refining does not allow complete use of copper anodes, peaking at 85% of the copper anode in weight. Consequently, the remaining 15% of scrap copper must be recirculated into the copper smelting. The use of reactive electrodyalysis is a system capable of continuously electro-refining scrap, by using a stainless steel basket and a cationic exchanging membrane in order to increase production of copper cathodes at the same percentage;it currently today returns to the copper smelter. In terms of specific energy consumption, this process would use between 3 and 4 times the value of normal electro-refining. 展开更多
关键词 Electro-Refining Copper scrap REACTIVE Electro-Dialysis
下载PDF
上一页 1 2 5 下一页 到第
使用帮助 返回顶部