Iron-rich electrolytic manganese residue(IREMR)is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In thi...Iron-rich electrolytic manganese residue(IREMR)is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In this study,the slurry electrolysis technique was used to recover high-purity Fe powder from IREMR.The effects of IREMR and H2SO4 mass ratio,current density,reaction temper-ature,and electrolytic time on the leaching and current efficiencies of Fe were studied.According to the results,high-purity Fe powder can be recovered from the cathode plate,and the slurry electrolyte can be recycled.The leaching efficiency,current efficiency,and purity of Fe reached 92.58%,80.65%,and 98.72wt%,respectively,at a 1:2.5 mass ratio of H2SO4 and IREMR,reaction temperature of 60℃,electric current density of 30 mA/cm^(2),and reaction time of 8 h.In addition,vibrating sample magnetometer(VSM)analysis showed that the coercivity of electrolytic iron powder was 54.5 A/m,which reached the advanced magnetic grade of electrical pure-iron powder(DT4A coercivity standard).The slurry electrolytic method provides fundamental support for the industrial application of Fe resource recovery in IRMER.展开更多
Solid physical properties are vital for the design, optimization, and scale-up of gas–liquid–solid multiphase reactors. The complex and interactional effects of the solid physical properties, including particle diam...Solid physical properties are vital for the design, optimization, and scale-up of gas–liquid–solid multiphase reactors. The complex and interactional effects of the solid physical properties, including particle diameter, density, wettability, and sphericity, on the hydrodynamic behaviors in a new external airlift loop reactor(EALR) integrating mixing and separation are decoupled in this work. Two semi-empirical equations are proposed and validated to predict the overall gas holdup and liquid circulating velocity satisfactorily, and then the individual influence of such solid physical properties is further investigated. The results demonstrate that both the overall gas holdup in the riser and the liquid circulating velocity in the downcomer increase with the contact angle, but decrease with particle size, density, and sphericity.Additionally, the impact of the particle size on the liquid circulating velocity is also profoundly revealed on a micro-level considering the particle size distribution. Moreover, the axial solid concentration distribution is discussed, and the uniformity of the slurry is described by the mixing index of the solid particles. The results show that a more homogeneous mixture can be achieved by adding finer particles other than attaining violent turbulence. Therefore, this work lays a foundation for the design, scale-up, and industrialization of the EALRs.展开更多
Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial ...Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial production can efectively enhance the surface quality of coating. To improve the processing performance of coated tools, micro abrasive slurry jet (MASJ) polishing technology is frst applied to the post-treatment of coated tools. Subsequently, the efects of process parameters on the surface quality and cutting thickness of coating are investigated via single-factor experiments. In the experiment, the best surface roughness is obtained by setting the working pressure to 0.4 MPa, particle size to 3 μm, incidence angle to 30°, and abrasive mass concentration to 100 g/L. Based on the results of the single-factor experiments, combination experiments are designed, and three types of coated tools with diferent surface qualities and coating thicknesses are obtained. The MASJ process for the post-treatment of coated tools is investigated based on a tool wear experiment and the efects of cutting parameters on the cutting force and workpiece surface quality of three types of cutting tools. The result indicates that MASJ machining can efectively improve the machining performance of coated tools.展开更多
The research on the multiphase flow characteristics of hydrate slurry is the key to implementing the risk prevention and control technology of hydrate slurry in deep-water oil and gas mixed transportation system.This ...The research on the multiphase flow characteristics of hydrate slurry is the key to implementing the risk prevention and control technology of hydrate slurry in deep-water oil and gas mixed transportation system.This paper established a geometric model based on the high-pressure hydrate slurry experimental loop.The model was used to carry out simulation research on the flow characteristics of gas-liquid-solid three-phase flow.The specific research is as follows:Firstly,the effects of factors such as slurry flow velocity,hydrate particle density,hydrate particle size,and hydrate volume fraction on the stratified smooth flow were specifically studied.Orthogonal test obtained particle size has the most influence on the particle concentration distribution.The slurry flow velocity is gradually increased based on stratified smooth flow.Various flow patterns were observed and their characteristics were analyzed.Secondly,increasing the slurry velocity to 2 m/s could achieve the slurry flow pattern of partial hydrate in the pipeline transition from stratified smooth flow to wavy flow.When the flow rate increases to 3 m/s,a violent wave forms throughout the entire loop.Based on wave flow,as the velocity increased to 4 m/s,and the flow pattern changed to slug flow.When the particle concentration was below 10%,the increase of the concentration would aggravate the slug flow trend;if the particle concentration was above 10%,the increase of the concentration would weaken the slug flow trend,the increase of particle density and liquid viscosity would weaken the tendency of slug flow.The relationship between the pressure drop gradients of several different flow patterns is:slug flow>wave flow>stratified smooth flow.展开更多
Estimation of stressses within the tailings slurry during self-weight consolidation is a critical issue for cost-effective barricade design and efficient backfill planning in underground mine stopes.This process requi...Estimation of stressses within the tailings slurry during self-weight consolidation is a critical issue for cost-effective barricade design and efficient backfill planning in underground mine stopes.This process requires a good understanding of self-weight consolidation behaviors of the tailings slurry within practical stopes,where many factors can have significant effects on the consolidation,including drainage condition and cement addition.In this paper,the prepared tailings slurry with different cement contents(0,4.76wt%,and 6.25wt%)was poured into1.2 m-high columns,which allowed three drainage scenarios(undrained,partial lateral drainage near the bottom part,and full lateral drainage boundaries)to investigate the effects of drainage condition and cement addition on the consolidation behavior of the tailings slurry.The consolidation behavior was analyzed in terms of pore water pressure(PWP),settlement,volume of drainage water,and residual water content.The results indicate that increasing the length of the drainage boundary or cement content aids in PWP dissipation.In addition,constructing an efficient drainage boundary was more favorable to PWP dissipation than increasing cement addition.The final stable PWP on the column floor was not sensitive to cement addition.The final settlement of uncemented tailings slurry was independent of drainage conditions,and that of cemented tailings slurry decreased with the increase in cement addition.Notably,more pore water can drain out from the cemented tailings slurry than the uncemented tailings slurry during consolidation.展开更多
Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes ...Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes into functional backfill materi-als.Unfortunately,how to efficiently deliver the slurry to the desired places remains under-researched.To address this issue,the computational fluid dynamics software Fluent was used in the current study in addition to a laboratory rheological test to simulate the impact of various parameters on the evolution of pressure at a particular section of the pipeline.Furthermore,the response surface method was employed to investigate how the various components and their corresponding influencing weights interact to affect the pressure drop.This study demonstrates that the pressure drop of the slurry is highly influenced by slurry concentration,speed,and pipe diameter.While conveying speed is the main component in the bend section,pipe diameter takes over in the horizontal and vertical pipe sections.展开更多
Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase a...Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.展开更多
Copper was extracted from methylchlorosilane slurry residue by a direct hydrogen peroxide leaching method.A number of experimental parameters were analyzed to determine the extraction efficiency of copper.The extracti...Copper was extracted from methylchlorosilane slurry residue by a direct hydrogen peroxide leaching method.A number of experimental parameters were analyzed to determine the extraction efficiency of copper.The extraction efficiency of copper reached 98.5%under the optimal leaching conditions,such as the hydrogen peroxide concentration of 1.875 mol·L^(-1),the leaching temperature of 323 K,the liquid–solid ratio of 20 ml·g^(-1),and the stirring speed of 300 r·min^(-1).The leaching kinetics of the copper extraction process was then described by the shrinking core model.There were two stages.The first stage was controlled by chemical reactions,while the second stage was controlled by interface transfer and product layer diffusion.The activation energy and kinetic control equations were determined,as well as an explanation of the leaching mechanism of copper extraction based on kinetic analysis and materials characterization.Copper resources can be recovered from the methylchlorosilane slurry residue efficiently and inexpensively with the methods used in this study.展开更多
Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and press...Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and pressures.Prevention of this problem requires,in general,excellent anti-channeling performances of the cement sheath.Three methods to predict such anti-channeling performances are proposed here,which use the weightless pressure of cement slurry,the permeability of cement stone and the volume expansion rate of cement sheath as input parameters.Guided by this approach,the anti-channeling performances of the cement slurry are evaluated by means of indoor experiments,and the cement slurry is optimized accordingly.The results show that the dangerous transition time of the cement slurry with optimized dosage of admixture is only 76 min,the permeability of cement stone is 0.005 md,the volume shrinkage at final setting is only 0.72%,and the anti-channeling performances are therefore maximized.The effective utilization of the optimized cement slurry in some representative wells(LD10–1-A1 and LD10–1-A2 in LD10–1 gas field)is also discussed.展开更多
The selective hydrogenation of polycyclic aromatic hydrocarbons(PAHs)from fluid catalytic cracking(FCC)slurry extract was conducted in a batch reactor over aγ-Al_(2)O_(3)-supported bimetallic Ni-W catalyst.For the Ni...The selective hydrogenation of polycyclic aromatic hydrocarbons(PAHs)from fluid catalytic cracking(FCC)slurry extract was conducted in a batch reactor over aγ-Al_(2)O_(3)-supported bimetallic Ni-W catalyst.For the Ni-W/γ-Al_(2)O_(3) catalyst,the experiment run was divided into three processes according to the reaction conditions used:(1)the absence of hydrogenation as both temperature and pressure increased;(2)the desulfurization of FCC slurry extract under a fixed pressure as the temperature increased;and(3)the selective hydrogenation of PAHs when both pressure and temperature remained constant.The hydrogen consumption could be accurately calculated from the Redlich–Kwong equation of state.The results for the removal of PAHs with hydrogenation displayed an excellent fit to the first-order kinetics.The apparent activation energy was determined to be 20.80 kJ/mol.展开更多
Bubble and slurry bubble column reactors(BCRs/SBCRs)are used for various chemical,biochemical,and petro-chemical applications.They have several operational and maintenance advantages,including excellent heat and mass ...Bubble and slurry bubble column reactors(BCRs/SBCRs)are used for various chemical,biochemical,and petro-chemical applications.They have several operational and maintenance advantages,including excellent heat and mass transfer rates,simplicity,and low operating and maintenance cost.Typically,a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products.Since most applications involve complicated gas-liquid,gas-liquid-solid,and exothermic processes,the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor’s overall performance.In this review,past and very recent experimental and numerical investigations on such systems are critically dis-cussed.Furthermore,gaps to befilled and critical aspects still requiring investigation are identified.展开更多
Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can ea...Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can easilyfill the leakage layer;moreover,its gelling strength can grow rapidly when pumping stops,thereby increasing the resistance to gas channeling,effectively preventing this undesired phenomenon in many cases.High-temperature thixotropic cement slurry systems,however,are still in an early stage of development and additional research is needed to make them a viable option.In the present study,using a self-developed composite high-temperature thixotropic additive as a basis,it is shown that the compressive strength can be adjusted by tuning the proportion of silica sand,the high-temperature retarder,fluid loss additive and dispersant(compatible with the thixotropic additive).According to the tests,the developed high-temperature thixotropic cement slurry system has a 14 d compressive strength of 29.73 MPa at 150°C,and a thickening time of 330 min when the dosage of retarder is 2%.At the same time,the rheological property,water loss,permeability,water separation rate,and settlement stability of the cement slurry system meet the requirements of cementing construction.展开更多
In this paper,based on Fluent software,a five-nozzle gasifier reactor was established to simulate the gasification process of oil-based drill cuttings coal-water slurry.The influence of concentration and oxygen/carbon...In this paper,based on Fluent software,a five-nozzle gasifier reactor was established to simulate the gasification process of oil-based drill cuttings coal-water slurry.The influence of concentration and oxygen/carbon atomic ratio on the gasification process of oil-based drill cuttings coal-water slurry was investigated.The results show that when the oxygen flow is constant,the outlet temperature of gasifier decreases,the content of effective gas increases,and the carbon conversion rate decreases with the increase of concentration;When the ratio of oxygen to carbon atoms is constant,the effective gas content rises and the temperature rises with the increase of the concentration,and the carbon conversion rate reaches the maximum value when the concentration of oil-based drill cuttings coal-water slurry is 65%;When the concentration is constant,the effective gas content decreases and the outlet temperature rises with the increase of the oxygen/carbon atom ratio,and the carbon conversion rate reaches 99.80%when the oxygen/carbon atom ratio is 1.03.It shows that this method can effectively decompose the organic matter in oilbased drill cuttings and realize the efficient and cooperative treatment of oil-based drill cuttings.展开更多
The volume change and shear strength behaviour of tailings slurry with the changes in gravimetric moisture content is important to effectively utilise the storage volume and analysis of dam failure potential.Consolida...The volume change and shear strength behaviour of tailings slurry with the changes in gravimetric moisture content is important to effectively utilise the storage volume and analysis of dam failure potential.Consolidation testing of tailings from a slurry-like to soil-like state is a critical task,and conventional consolidation apparatus does not have the capability of doing such testing,as the tailings slurries contain high water content.Settling tests conducted on slurries having a 25%solids concentration showed very low efficiency;final sediment was still slurry-like.An intrinsic point was identified based on pore water pressure dissipation during consolidation tests in a slurry consolidometer that can define two states of the tailings i.e.slurry-like and soil-like.In the slurry-like state,the volume change was greater for Slurry 2 than Slurry 1,while the inverse was observed in the soil-like state.The evolution of peak vane shear strength with the changes in moisture content was almost similar for both samples and obeyed the power function.Regression models have been developed and validated to predict the shear strength of materials at any gravimetric moisture content or void ratio.展开更多
The present work aimed to study the effect of slurry conditioning on flocculant-aided filtration of coal tailings by the analysis of filtration kinetics and filter cake structure.Laboratory filtration tests of the coa...The present work aimed to study the effect of slurry conditioning on flocculant-aided filtration of coal tailings by the analysis of filtration kinetics and filter cake structure.Laboratory filtration tests of the coal tailings showed that both the shear rate and agitation time have significant effects on filtration rate and cake moisture.Moderate agitation at the shear rate of 92 s^-1 was favorable for fast filtration,but high cake moisture was encountered.The low-field 1H nuclear magnetic resonance(NMR)measurements of the filter cake showed that the slurry conditioning has a significant effect on the residual water in large pores and a negligible effect on the residual water in small pores.The X-ray micro-tomography(XRM)measurements indicated that the filter cake formed at the shear rate of 92 s^-1 has more macro-pores and higher porosity than that formed at the shear rate of 53 s1,hence more residual water was entrapped in filter cake.The slurry conditioning in the presence of flocculant will change the structure of filter cake and affect the filtration performance.There was a paradox between fast filtration rate and low filter cake moisture.The findings enable better understanding of the effect of slurry conditioning on flocculant-aided filtration of coal tailings.展开更多
Massive amounts of biogas slurry are produced due to the development of biogas plants.The pollution features and the risk of biogas slurry were fully evaluated in this work.Thirty-one biogas slurry samples were collec...Massive amounts of biogas slurry are produced due to the development of biogas plants.The pollution features and the risk of biogas slurry were fully evaluated in this work.Thirty-one biogas slurry samples were collected from sixteen different cities and five different raw materials biogas plants(e.g.cattle manure,swine manure,straw-manure mixture,kitchen waste and chicken manure).The chemical oxygen demand(COD),ammonia nitrogen(NH_(4)^(+)-N),anions(e.g.Cl^(-1),SO_(4)^(2-),NO_(3)^(-)and PO_(4)^(3-)),antibiotics(e.g.sulphonamides,quinolones,β2-receptor agonists,macrolides,tetracyclines and crystal violet)and heavy metals(e.g.Cu,Cd,As,Cr,Hg,Zn and Pb)contents from these biogas slurry samples were systematically investigated.On this basis,risk assessment of biogas slurry was also performed.The concentrations of COD,NH_(4)^(+)-N and PO_(4)^(3-) in biogas slurry samples with chicken manure as raw material were significantly higher than those of other raw materials.Therefore,the biogas slurry from chicken manure raw material demonstrated the most serious eutrophication threat.The antibiotic contents in biogas slurry samples from swine manure were the highest among five raw materials,mostly sulphonamides,quinolones and tetracyclines.Biogas slurry revealed particularly serious arsenic contamination and moderate potential ecological risk.The quadratic polynomial stepwise regression model can quantitatively describe the correlation among NH_(4)^(+)-N,PO_(4)^(3+) and heavy metals concentration of biogas slurry.This work demonstrated a universal potential threat from biogas slurry that can provide supporting data and theoretical basis for harmless treatment and reuse of biogas slurry.展开更多
The rheo-diecasting mold filling capacity and the microstructure of the semi-solid A380 aluminum alloy slurry were investigated. The results show that the mold filling capacity was strengthened with increasing pouring...The rheo-diecasting mold filling capacity and the microstructure of the semi-solid A380 aluminum alloy slurry were investigated. The results show that the mold filling capacity was strengthened with increasing pouring temperature or increasing injection pressure. Under certain process parameters, the mold cavity was fully filled. However, the mold filling capacity decreased with increasing holding time. The mold filling capacity was improved with increasing shape factor of primary α(Al) grains; however, the solid fraction and the grain size significantly increased at the same time. In addition, the microstructures along the route of the spiral samples obviously differed. The grain size decreased gradually from the near-end to the far-end, whereas the shape factor increased gradually.展开更多
In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cav...In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cavitation effect of ultrasonic vibration. By application of quantitative gas content measurement technique, this paper investigated the effect of the ultrasonic vibration on the gas content of both the melt and the semi-solid slurry of Al-Si alloys, and the variations of the gas contents in two kinds of aluminum alloys, i.e., A356 alloy and Al-20Si-2Cu-1Ni-0.6RE alloy (Al-20Si for short). The results show that ultrasonic vibration has an obvious degassing effect on the molten melt, especially on the semi-solid slurry of Al-Si alloy which is below the liquidus temperature by less than 20 ℃. The ultrasonic degassing efficiency of the A356 alloy decreases with the reduction of the initial gas content in the melt, and it is nearly unchanged for the Al-20Si alloy. The gas content of both alloys decreases when the ultrasonic vibration time is increased. The best vibration time for Al-20Si alloy at the liquid temperature of 710 ℃ and semi-solid temperature of 680 ℃ is 60 s and 90 s, respectively; and the degassing efficiency is 48% and 35%, respectively. The mechanism of ultrasonic degassing effect is discussed.展开更多
In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to inv...In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to investigate the pulping properties and microscopic mechanism of the LCWS samples prepared using the two agents,so as to explore the influence of benzene ring on the performance of dispersant.The results of the LCWS preparation experiments revealed that the pulp-forming performance of PDPE exceeded that of PLE.When LCWS concentration is 62%,64%,and 66%,the apparent viscosity corresponding to PDPE is 247.80,504.17,and 653.10 mPa·s,and the apparent viscosity corresponding to PLE is 548.10,1470.61,and 1549.98 mPa·s,respectively.The C_(1000)(When the apparent viscosity is 1000 mPa·s,the corresponding concentration of LCWS is defined as C_(1000))values of PDPE and PLE are 67.60%and 62.95%,respectively.In addition to the van der Waals forces and hydrogen bonds between the PDPE and/or PLE molecules and coal,the benzene rings of PDPE presentπ-πstacking effect with the aromatic rings of coal.That could facilitate and strengthen the adsorption of PDPE on coal,which would be conducive to further improving the dispersion of coal particles.The two dispersants have no significant difference in effect on the pyrolysis of LCWS.The simulation results indicated that the times for PDPE and PLE molecules to reach flat adsorption state on coal are approximately 290 and 565 ps,respectively.The self-diffusion coefficient(D)of the PDPE and PLE on coal is 3.16 x 10^(-6)and6.57×10^(-6)m~2/s,respectively,and their interaction energies with coal are 785.71 and 648.60 kcal/mol,respectively.The results of the simulation calculations demonstrated that PDPE adsorbed on coal easier than PLE,and its binding is more stable than that of PLE owing to theπ-πstacking effect,which is conducive to uniform dispersion of coal in solution.The simulation results confirmed the experimental results.展开更多
A new method was exploited using solution treatment and aging process as a pretreatment in preparing semi-solid slurry with fine microstructure before isothermal treatment of wrought aluminum alloy 7A09.Parameters of ...A new method was exploited using solution treatment and aging process as a pretreatment in preparing semi-solid slurry with fine microstructure before isothermal treatment of wrought aluminum alloy 7A09.Parameters of pretreatment were optimized by orthogonal experiment design and proper precursor was prepared.The evolution of microstructure of semi-solid slurry during isothermal treatment was analyzed and the mechanism of microstructure refining was discussed.The result of orthogonal experiment design shows that the optimum parameters are 462 ℃for solution temperature,40min for solution time,132 ℃for aging temperature and 14 h for aging time.Microstructure of isothermal treatment is fine,homogenous,with globular solid grains and a solid fraction between 50%and 70%,which is qualified for later semi-solid forming process.Mechanism of microstructure evolution includes the agglomeration ofα-phase and Ostwald ripening.Precipitations prepared by solution and aging treatment prevent the grains from coarsening and promote the grain ripening to globular shape.展开更多
基金supported by the Key Research and Development Program of Guangxi Province,China (No.AB23075174)the National Natural Science Foundation of China (No.52174386)the Science and Technology Plan Project of Sichuan Province,China (No.2022YFS0459).
文摘Iron-rich electrolytic manganese residue(IREMR)is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In this study,the slurry electrolysis technique was used to recover high-purity Fe powder from IREMR.The effects of IREMR and H2SO4 mass ratio,current density,reaction temper-ature,and electrolytic time on the leaching and current efficiencies of Fe were studied.According to the results,high-purity Fe powder can be recovered from the cathode plate,and the slurry electrolyte can be recycled.The leaching efficiency,current efficiency,and purity of Fe reached 92.58%,80.65%,and 98.72wt%,respectively,at a 1:2.5 mass ratio of H2SO4 and IREMR,reaction temperature of 60℃,electric current density of 30 mA/cm^(2),and reaction time of 8 h.In addition,vibrating sample magnetometer(VSM)analysis showed that the coercivity of electrolytic iron powder was 54.5 A/m,which reached the advanced magnetic grade of electrical pure-iron powder(DT4A coercivity standard).The slurry electrolytic method provides fundamental support for the industrial application of Fe resource recovery in IRMER.
基金supported by the National Natural Science Foundation of China (21878318, 22108285)the DNL Cooperation Fund, CAS (DNL201902)+2 种基金“Transformational Technologies for Clean Energy and Demonstration”, Strategic Priority Research Program of the Chinese Academy of Sciences (CAS) (XDA21060400)Shandong Energy Institute, Single-Cell Center Project (SCZ-16, SCZ17)Director Innovation Fund of Synthetic Biology Technology Innovation Center of Shandong Province (sdsynbio-2020-ZH-02)。
文摘Solid physical properties are vital for the design, optimization, and scale-up of gas–liquid–solid multiphase reactors. The complex and interactional effects of the solid physical properties, including particle diameter, density, wettability, and sphericity, on the hydrodynamic behaviors in a new external airlift loop reactor(EALR) integrating mixing and separation are decoupled in this work. Two semi-empirical equations are proposed and validated to predict the overall gas holdup and liquid circulating velocity satisfactorily, and then the individual influence of such solid physical properties is further investigated. The results demonstrate that both the overall gas holdup in the riser and the liquid circulating velocity in the downcomer increase with the contact angle, but decrease with particle size, density, and sphericity.Additionally, the impact of the particle size on the liquid circulating velocity is also profoundly revealed on a micro-level considering the particle size distribution. Moreover, the axial solid concentration distribution is discussed, and the uniformity of the slurry is described by the mixing index of the solid particles. The results show that a more homogeneous mixture can be achieved by adding finer particles other than attaining violent turbulence. Therefore, this work lays a foundation for the design, scale-up, and industrialization of the EALRs.
基金Supported by National Natural Science Foundation of China(Grant No.51735003)Research Start-up Fee for Doctoral Personnel of Binzhou University of China(Grant No.2019Y12)Key Program of NSFC-Guangdong Joint Fund of China(Grant No.U1201245).
文摘Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial production can efectively enhance the surface quality of coating. To improve the processing performance of coated tools, micro abrasive slurry jet (MASJ) polishing technology is frst applied to the post-treatment of coated tools. Subsequently, the efects of process parameters on the surface quality and cutting thickness of coating are investigated via single-factor experiments. In the experiment, the best surface roughness is obtained by setting the working pressure to 0.4 MPa, particle size to 3 μm, incidence angle to 30°, and abrasive mass concentration to 100 g/L. Based on the results of the single-factor experiments, combination experiments are designed, and three types of coated tools with diferent surface qualities and coating thicknesses are obtained. The MASJ process for the post-treatment of coated tools is investigated based on a tool wear experiment and the efects of cutting parameters on the cutting force and workpiece surface quality of three types of cutting tools. The result indicates that MASJ machining can efectively improve the machining performance of coated tools.
基金supported by the National Natural Science Foundation of China(Grant No.52274061&52004039&51974037)China Postdoctoral Science Foundation(Grant No.2023T160717&2021M693908)+1 种基金The major project of universities affiliated to Jiangsu Province basic science(natural science)research(Grant No.21KJA440001)Jiangsu Qinglan Project,Changzhou Longcheng Talent Plan-Youth Science and Technology Talent Recruitment Project.
文摘The research on the multiphase flow characteristics of hydrate slurry is the key to implementing the risk prevention and control technology of hydrate slurry in deep-water oil and gas mixed transportation system.This paper established a geometric model based on the high-pressure hydrate slurry experimental loop.The model was used to carry out simulation research on the flow characteristics of gas-liquid-solid three-phase flow.The specific research is as follows:Firstly,the effects of factors such as slurry flow velocity,hydrate particle density,hydrate particle size,and hydrate volume fraction on the stratified smooth flow were specifically studied.Orthogonal test obtained particle size has the most influence on the particle concentration distribution.The slurry flow velocity is gradually increased based on stratified smooth flow.Various flow patterns were observed and their characteristics were analyzed.Secondly,increasing the slurry velocity to 2 m/s could achieve the slurry flow pattern of partial hydrate in the pipeline transition from stratified smooth flow to wavy flow.When the flow rate increases to 3 m/s,a violent wave forms throughout the entire loop.Based on wave flow,as the velocity increased to 4 m/s,and the flow pattern changed to slug flow.When the particle concentration was below 10%,the increase of the concentration would aggravate the slug flow trend;if the particle concentration was above 10%,the increase of the concentration would weaken the slug flow trend,the increase of particle density and liquid viscosity would weaken the tendency of slug flow.The relationship between the pressure drop gradients of several different flow patterns is:slug flow>wave flow>stratified smooth flow.
基金financially supported by the Young Scientist Project of the National Key Research and Development Program of China (No.2021YFC2900600)the Beijing Nova Program (No.20220484057)financial support from China Scholarship Council under Grant CSC No.202110300001。
文摘Estimation of stressses within the tailings slurry during self-weight consolidation is a critical issue for cost-effective barricade design and efficient backfill planning in underground mine stopes.This process requires a good understanding of self-weight consolidation behaviors of the tailings slurry within practical stopes,where many factors can have significant effects on the consolidation,including drainage condition and cement addition.In this paper,the prepared tailings slurry with different cement contents(0,4.76wt%,and 6.25wt%)was poured into1.2 m-high columns,which allowed three drainage scenarios(undrained,partial lateral drainage near the bottom part,and full lateral drainage boundaries)to investigate the effects of drainage condition and cement addition on the consolidation behavior of the tailings slurry.The consolidation behavior was analyzed in terms of pore water pressure(PWP),settlement,volume of drainage water,and residual water content.The results indicate that increasing the length of the drainage boundary or cement content aids in PWP dissipation.In addition,constructing an efficient drainage boundary was more favorable to PWP dissipation than increasing cement addition.The final stable PWP on the column floor was not sensitive to cement addition.The final settlement of uncemented tailings slurry was independent of drainage conditions,and that of cemented tailings slurry decreased with the increase in cement addition.Notably,more pore water can drain out from the cemented tailings slurry than the uncemented tailings slurry during consolidation.
文摘Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes into functional backfill materi-als.Unfortunately,how to efficiently deliver the slurry to the desired places remains under-researched.To address this issue,the computational fluid dynamics software Fluent was used in the current study in addition to a laboratory rheological test to simulate the impact of various parameters on the evolution of pressure at a particular section of the pipeline.Furthermore,the response surface method was employed to investigate how the various components and their corresponding influencing weights interact to affect the pressure drop.This study demonstrates that the pressure drop of the slurry is highly influenced by slurry concentration,speed,and pipe diameter.While conveying speed is the main component in the bend section,pipe diameter takes over in the horizontal and vertical pipe sections.
基金Central Applied Research Laboratory(CARL)Center of Materials ResearchDepartment of Materials Science and Metallurgy,Shahid Bahonar University of Kerman(SBUK)for support of this work。
文摘Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.
基金supported by the National Key Research and Development Program of China (2018YFC1901804 and 2018YFC1901805)the National Natural Science Foundation of China (21978045 and U1902219)。
文摘Copper was extracted from methylchlorosilane slurry residue by a direct hydrogen peroxide leaching method.A number of experimental parameters were analyzed to determine the extraction efficiency of copper.The extraction efficiency of copper reached 98.5%under the optimal leaching conditions,such as the hydrogen peroxide concentration of 1.875 mol·L^(-1),the leaching temperature of 323 K,the liquid–solid ratio of 20 ml·g^(-1),and the stirring speed of 300 r·min^(-1).The leaching kinetics of the copper extraction process was then described by the shrinking core model.There were two stages.The first stage was controlled by chemical reactions,while the second stage was controlled by interface transfer and product layer diffusion.The activation energy and kinetic control equations were determined,as well as an explanation of the leaching mechanism of copper extraction based on kinetic analysis and materials characterization.Copper resources can be recovered from the methylchlorosilane slurry residue efficiently and inexpensively with the methods used in this study.
基金funded by the CNOOC Scientific Research Project“Study of cementing key properties and its matching technology of LD-10 gas field”(Grant No.CCL2019ZJFN1227).
文摘Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and pressures.Prevention of this problem requires,in general,excellent anti-channeling performances of the cement sheath.Three methods to predict such anti-channeling performances are proposed here,which use the weightless pressure of cement slurry,the permeability of cement stone and the volume expansion rate of cement sheath as input parameters.Guided by this approach,the anti-channeling performances of the cement slurry are evaluated by means of indoor experiments,and the cement slurry is optimized accordingly.The results show that the dangerous transition time of the cement slurry with optimized dosage of admixture is only 76 min,the permeability of cement stone is 0.005 md,the volume shrinkage at final setting is only 0.72%,and the anti-channeling performances are therefore maximized.The effective utilization of the optimized cement slurry in some representative wells(LD10–1-A1 and LD10–1-A2 in LD10–1 gas field)is also discussed.
基金financially supported by the Natural Science Foundation of Jiangsu Province (Grant number:BK20140260)the Joint Project of Industry-UniversityResearch of Jiangsu Province (Grant number:BY2018158 and BY2021590)+1 种基金the CNPC-CZU Innovation Alliance,the Jiangsu Province Key Laboratory of Fine Petrochemical Engineering (Grant number:KF2302)the State Key Laboratory of Heavy Oil Processing。
文摘The selective hydrogenation of polycyclic aromatic hydrocarbons(PAHs)from fluid catalytic cracking(FCC)slurry extract was conducted in a batch reactor over aγ-Al_(2)O_(3)-supported bimetallic Ni-W catalyst.For the Ni-W/γ-Al_(2)O_(3) catalyst,the experiment run was divided into three processes according to the reaction conditions used:(1)the absence of hydrogenation as both temperature and pressure increased;(2)the desulfurization of FCC slurry extract under a fixed pressure as the temperature increased;and(3)the selective hydrogenation of PAHs when both pressure and temperature remained constant.The hydrogen consumption could be accurately calculated from the Redlich–Kwong equation of state.The results for the removal of PAHs with hydrogenation displayed an excellent fit to the first-order kinetics.The apparent activation energy was determined to be 20.80 kJ/mol.
文摘Bubble and slurry bubble column reactors(BCRs/SBCRs)are used for various chemical,biochemical,and petro-chemical applications.They have several operational and maintenance advantages,including excellent heat and mass transfer rates,simplicity,and low operating and maintenance cost.Typically,a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products.Since most applications involve complicated gas-liquid,gas-liquid-solid,and exothermic processes,the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor’s overall performance.In this review,past and very recent experimental and numerical investigations on such systems are critically dis-cussed.Furthermore,gaps to befilled and critical aspects still requiring investigation are identified.
基金funded by the National Natural Science Foundation of China(51974355).
文摘Cementing carbonate reservoirs is generally a difficult task.The so-called thixotropic cement slurry has gained considerable attention in this regard as it can help tofix some notable problems.More precisely,it can easilyfill the leakage layer;moreover,its gelling strength can grow rapidly when pumping stops,thereby increasing the resistance to gas channeling,effectively preventing this undesired phenomenon in many cases.High-temperature thixotropic cement slurry systems,however,are still in an early stage of development and additional research is needed to make them a viable option.In the present study,using a self-developed composite high-temperature thixotropic additive as a basis,it is shown that the compressive strength can be adjusted by tuning the proportion of silica sand,the high-temperature retarder,fluid loss additive and dispersant(compatible with the thixotropic additive).According to the tests,the developed high-temperature thixotropic cement slurry system has a 14 d compressive strength of 29.73 MPa at 150°C,and a thickening time of 330 min when the dosage of retarder is 2%.At the same time,the rheological property,water loss,permeability,water separation rate,and settlement stability of the cement slurry system meet the requirements of cementing construction.
基金This research was funded by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX21_2815).
文摘In this paper,based on Fluent software,a five-nozzle gasifier reactor was established to simulate the gasification process of oil-based drill cuttings coal-water slurry.The influence of concentration and oxygen/carbon atomic ratio on the gasification process of oil-based drill cuttings coal-water slurry was investigated.The results show that when the oxygen flow is constant,the outlet temperature of gasifier decreases,the content of effective gas increases,and the carbon conversion rate decreases with the increase of concentration;When the ratio of oxygen to carbon atoms is constant,the effective gas content rises and the temperature rises with the increase of the concentration,and the carbon conversion rate reaches the maximum value when the concentration of oil-based drill cuttings coal-water slurry is 65%;When the concentration is constant,the effective gas content decreases and the outlet temperature rises with the increase of the oxygen/carbon atom ratio,and the carbon conversion rate reaches 99.80%when the oxygen/carbon atom ratio is 1.03.It shows that this method can effectively decompose the organic matter in oilbased drill cuttings and realize the efficient and cooperative treatment of oil-based drill cuttings.
文摘The volume change and shear strength behaviour of tailings slurry with the changes in gravimetric moisture content is important to effectively utilise the storage volume and analysis of dam failure potential.Consolidation testing of tailings from a slurry-like to soil-like state is a critical task,and conventional consolidation apparatus does not have the capability of doing such testing,as the tailings slurries contain high water content.Settling tests conducted on slurries having a 25%solids concentration showed very low efficiency;final sediment was still slurry-like.An intrinsic point was identified based on pore water pressure dissipation during consolidation tests in a slurry consolidometer that can define two states of the tailings i.e.slurry-like and soil-like.In the slurry-like state,the volume change was greater for Slurry 2 than Slurry 1,while the inverse was observed in the soil-like state.The evolution of peak vane shear strength with the changes in moisture content was almost similar for both samples and obeyed the power function.Regression models have been developed and validated to predict the shear strength of materials at any gravimetric moisture content or void ratio.
基金the Natural Science Foundation of Jiangsu Province(BK20180657)。
文摘The present work aimed to study the effect of slurry conditioning on flocculant-aided filtration of coal tailings by the analysis of filtration kinetics and filter cake structure.Laboratory filtration tests of the coal tailings showed that both the shear rate and agitation time have significant effects on filtration rate and cake moisture.Moderate agitation at the shear rate of 92 s^-1 was favorable for fast filtration,but high cake moisture was encountered.The low-field 1H nuclear magnetic resonance(NMR)measurements of the filter cake showed that the slurry conditioning has a significant effect on the residual water in large pores and a negligible effect on the residual water in small pores.The X-ray micro-tomography(XRM)measurements indicated that the filter cake formed at the shear rate of 92 s^-1 has more macro-pores and higher porosity than that formed at the shear rate of 53 s1,hence more residual water was entrapped in filter cake.The slurry conditioning in the presence of flocculant will change the structure of filter cake and affect the filtration performance.There was a paradox between fast filtration rate and low filter cake moisture.The findings enable better understanding of the effect of slurry conditioning on flocculant-aided filtration of coal tailings.
基金supported by the National Natural Science Foundation of China(22038012,42077030)the Science and Technology Program of Fujian Province,China(2020NZ012015,2020Y4002)the Fundamental Research Funds for the Central Universities of China(20720190001)。
文摘Massive amounts of biogas slurry are produced due to the development of biogas plants.The pollution features and the risk of biogas slurry were fully evaluated in this work.Thirty-one biogas slurry samples were collected from sixteen different cities and five different raw materials biogas plants(e.g.cattle manure,swine manure,straw-manure mixture,kitchen waste and chicken manure).The chemical oxygen demand(COD),ammonia nitrogen(NH_(4)^(+)-N),anions(e.g.Cl^(-1),SO_(4)^(2-),NO_(3)^(-)and PO_(4)^(3-)),antibiotics(e.g.sulphonamides,quinolones,β2-receptor agonists,macrolides,tetracyclines and crystal violet)and heavy metals(e.g.Cu,Cd,As,Cr,Hg,Zn and Pb)contents from these biogas slurry samples were systematically investigated.On this basis,risk assessment of biogas slurry was also performed.The concentrations of COD,NH_(4)^(+)-N and PO_(4)^(3-) in biogas slurry samples with chicken manure as raw material were significantly higher than those of other raw materials.Therefore,the biogas slurry from chicken manure raw material demonstrated the most serious eutrophication threat.The antibiotic contents in biogas slurry samples from swine manure were the highest among five raw materials,mostly sulphonamides,quinolones and tetracyclines.Biogas slurry revealed particularly serious arsenic contamination and moderate potential ecological risk.The quadratic polynomial stepwise regression model can quantitatively describe the correlation among NH_(4)^(+)-N,PO_(4)^(3+) and heavy metals concentration of biogas slurry.This work demonstrated a universal potential threat from biogas slurry that can provide supporting data and theoretical basis for harmless treatment and reuse of biogas slurry.
基金financially supported by the National Basic Research Program of China (No. 2011CB606300)the National Natural Science Foundation of China (No. 5077400)
文摘The rheo-diecasting mold filling capacity and the microstructure of the semi-solid A380 aluminum alloy slurry were investigated. The results show that the mold filling capacity was strengthened with increasing pouring temperature or increasing injection pressure. Under certain process parameters, the mold cavity was fully filled. However, the mold filling capacity decreased with increasing holding time. The mold filling capacity was improved with increasing shape factor of primary α(Al) grains; however, the solid fraction and the grain size significantly increased at the same time. In addition, the microstructures along the route of the spiral samples obviously differed. The grain size decreased gradually from the near-end to the far-end, whereas the shape factor increased gradually.
基金supported by the National Natural Science Foundation of China (No. 50775086)the National Basic Research Program of China (973 Program, No. 2012CB619600)
文摘In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cavitation effect of ultrasonic vibration. By application of quantitative gas content measurement technique, this paper investigated the effect of the ultrasonic vibration on the gas content of both the melt and the semi-solid slurry of Al-Si alloys, and the variations of the gas contents in two kinds of aluminum alloys, i.e., A356 alloy and Al-20Si-2Cu-1Ni-0.6RE alloy (Al-20Si for short). The results show that ultrasonic vibration has an obvious degassing effect on the molten melt, especially on the semi-solid slurry of Al-Si alloy which is below the liquidus temperature by less than 20 ℃. The ultrasonic degassing efficiency of the A356 alloy decreases with the reduction of the initial gas content in the melt, and it is nearly unchanged for the Al-20Si alloy. The gas content of both alloys decreases when the ultrasonic vibration time is increased. The best vibration time for Al-20Si alloy at the liquid temperature of 710 ℃ and semi-solid temperature of 680 ℃ is 60 s and 90 s, respectively; and the degassing efficiency is 48% and 35%, respectively. The mechanism of ultrasonic degassing effect is discussed.
基金supported by National Natural Science Foundation of China(Nos.51904174 and 52074175)Postdoctoral Science Foundation of China(No.2019M662403)+3 种基金Young Science and Technology Innovation Program of Shandong Province(No.2020KJD001)Key Research and Development Project of Shandong(No.2019GGX103035)SDUST Research Fund(No.2018TDJH101)Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team。
文摘In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to investigate the pulping properties and microscopic mechanism of the LCWS samples prepared using the two agents,so as to explore the influence of benzene ring on the performance of dispersant.The results of the LCWS preparation experiments revealed that the pulp-forming performance of PDPE exceeded that of PLE.When LCWS concentration is 62%,64%,and 66%,the apparent viscosity corresponding to PDPE is 247.80,504.17,and 653.10 mPa·s,and the apparent viscosity corresponding to PLE is 548.10,1470.61,and 1549.98 mPa·s,respectively.The C_(1000)(When the apparent viscosity is 1000 mPa·s,the corresponding concentration of LCWS is defined as C_(1000))values of PDPE and PLE are 67.60%and 62.95%,respectively.In addition to the van der Waals forces and hydrogen bonds between the PDPE and/or PLE molecules and coal,the benzene rings of PDPE presentπ-πstacking effect with the aromatic rings of coal.That could facilitate and strengthen the adsorption of PDPE on coal,which would be conducive to further improving the dispersion of coal particles.The two dispersants have no significant difference in effect on the pyrolysis of LCWS.The simulation results indicated that the times for PDPE and PLE molecules to reach flat adsorption state on coal are approximately 290 and 565 ps,respectively.The self-diffusion coefficient(D)of the PDPE and PLE on coal is 3.16 x 10^(-6)and6.57×10^(-6)m~2/s,respectively,and their interaction energies with coal are 785.71 and 648.60 kcal/mol,respectively.The results of the simulation calculations demonstrated that PDPE adsorbed on coal easier than PLE,and its binding is more stable than that of PLE owing to theπ-πstacking effect,which is conducive to uniform dispersion of coal in solution.The simulation results confirmed the experimental results.
基金Project(2007-83)supported by Science and Technology Development Projects of Weihai,Shandong Province。
文摘A new method was exploited using solution treatment and aging process as a pretreatment in preparing semi-solid slurry with fine microstructure before isothermal treatment of wrought aluminum alloy 7A09.Parameters of pretreatment were optimized by orthogonal experiment design and proper precursor was prepared.The evolution of microstructure of semi-solid slurry during isothermal treatment was analyzed and the mechanism of microstructure refining was discussed.The result of orthogonal experiment design shows that the optimum parameters are 462 ℃for solution temperature,40min for solution time,132 ℃for aging temperature and 14 h for aging time.Microstructure of isothermal treatment is fine,homogenous,with globular solid grains and a solid fraction between 50%and 70%,which is qualified for later semi-solid forming process.Mechanism of microstructure evolution includes the agglomeration ofα-phase and Ostwald ripening.Precipitations prepared by solution and aging treatment prevent the grains from coarsening and promote the grain ripening to globular shape.
