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Thiosullate is considered to be the most promising gold extraction reagent in gold leaching process due to its advantages of non-toxicity and high efficiency. The electrochemical behavior of gold electrode in Cu2+-en-S2 O$_ gold leaching system was investigated by electrochemical testing methods (open circuit potential, cyclic voltammetry, Talel curve and electrochemical impedance). Characterization ol surlace oxidation products ol gold electrodes using Raman spectroscopy and XPS, and the oxidation mechanism ol gold was clarilied. The experimental results show that S2O32- can promote the oxidation ol the gold surface, and under the electrochemical conditions in this paper, the reaction rate is controlled by the step ol charge transfer when the gold electrode is in the 5 mmol/L Cu2+-10 mmol/L en-100 mmol/L S2O32- system. The thiosullate concentration in the system controls the dissolution ol gold by allecting its surlace properties and surlace reaction rate. The electrochemical oxidation mechanism ol gold electrodes in the Cu,十一en-S2O32- leaching gold system was this paper elucidated, and a theoretical basis was provided for the regulation ol the composition ol gold leaching reagents. [ABSTRACT FROM AUTHOR]

Zinc-copper alloy ash contains Cu, Zn, Al, Ni, Sn, Pb and other non-ferrous metals. In this paper, t he effective treatment of zmccopper ash in different particle size ranges ss realized by screening. The effects of sulfuric acid content, temperature, time, i iquid-soiid ratio, rotation speed, oxidant and roasting conditions on the selective eaching of different meta! were investigated. The resutts show that the zinccopper ash with partid size kss than 0. 15 mm ss caHned at 750 °C for 3 hours, and then leached at 85 °C, s uHunc acid content of 1. 2 g/g ash, iiquid-to-solid ratio of 5/1, sirring speed of 400 r/min, H202 0. 075 mL/g ash for 5 h. The removal rate of zinc ss 93. 40%, and the removal rate of copper ss 0. 23%. Compared with the initia1 copper ash, the ZnO n the copper ash after roasting and leaching ss greatly reduced. The leaching residue was mixed with copper slag with a particle size of 0. 15-0. 25 mm, roasted at 750 C for 4 hours, and then washed wI 2 mol/L suHurtc acid solution for 5 hours and washed wI water under the same condiions. The steps can remove a !arge number of impurtty metal e!ements inthe copper slag. The phase composition of the copper slag after pickling is mainly Cu, and the proportion of Cu elements reach 92. 52%. [ABSTRACT FROM AUTHOR]

Based on the problem of nickel remove from ferrous sulphate solution with low nickel content, it was Investigated by on exchange process in this paper. Different factors, including resin tilting capacity, pH, time, initial nickel content and so on, were investigated to explore the performance of nickel remove from ferrous sulphate solution by designed experiments. The resutts indicate that priority se1ectivity for nickel ss presented in ferrous sulphate solution after resin adsorption and the operating capacity of CH-90 resin for nickel ss 15 mg/g. After resin adsorption,Fe/Ni molar ratio ss increased from 17 : 1 to 93 : 1 and removal rate on nickel reached 87%. Additiona11y,nickel content ss reduced to 0. 3 g/L. In other words,nickel ss removed effectually from ferrous sulphate solution. The adsorption isotherms and adsorption kinetics were evaluated by changing the initial content and adsorption reaction time. It was found that the resin was in tine with the Langmuir adsorption ssotherm,and met the quasi-second-order kinetic equation. Furthermore,adsorption process was mainly controlled by on exchange. [ABSTRACT FROM AUTHOR]

:In paper, recycled Al-1.15Mg-1.02Si-0.7Cu alloy was optical prepared by meiting and casting, the microstructural evolution of the alloy were analyzed by using optical nicroscopy(OM), scanning e!ectron microscopy (SEM), e!ectron back scattered diffraciion(EBSD) and transmission e!ectron nicroscope(TEM),the effects of heal treatment on the mechanical and corrosionlresistant properties of the extruded proUes were invesiigated. The results show that the recrystaliization of the alloy was competed by soiid solution at 550C and fine equaaxaal crystass were obtanned. The iime required for the alloys to reach peak hardness under artificia1 aging cond!tions at 155,175 and 195 C was 18,8 and 4 h, respectively, and the peak hardnesses were 132.96 HV,132. 94 HV and 132.22 HV, respectively, wtth the extruded profiles obtanning the highest tensle strength of 410. 42 MPa and higher elongation of 14. 75% under aging cond!tions at 175 C/8 h. The optimizedsoid solution process ss 550 C/1 hand the artifidal aging process ss 175 C/8 h. The tendency of the alloy to intergranular corrosion ss more pronounced,and the alloy corrodes most severely under peakaged cond!tions, followed by over-aged and weakest underaged. [ABSTRACT FROM AUTHOR]

Atmtng at the problem that brittle Ti-Fe intermetalHc compounds are easily formed tn the additive manufacturing process of titanium/steel composites, which deteriorates the interface properties. In this paper, n^kel (ERN-1)was se!ected as the Interlayer,and the integrated preparation of TC4/309L composites was reaiized by laser fuse additive manufacturing technology. The effect of Ni interlayer addition on the rmcrostructure and properties of the interface was analyzed. The resuits show that "The interface of TC4/309L composites with Ni interlayer Is mainly composed of Fe/Ni interface and Ti/Ni interface. For the Fe/Ni interface,Fe and Ni form an infinite soiid solution, and no obvious defects such as cracks and pores are found, achieving a good metallurgical bonding. The Ti/Ni interface contains TiFe,TiNi3,TiNi,Ti2Ni and other brittle intermetalic compounds,and the maximum hardness of the interface reaches 670. 1 HV. The micro-area tensie test of the interface bondng strength shows that the bonding strength is 30. 5 MPa,and it breaks at the Ti/Ni Interface,showing brittie fracture characteristics. [ABSTRACT FROM AUTHOR]

During underground mining using room and pillar method or room and pillar subsequent filling mining method, in order to ensure the stability of the quarry, most of the pillars are often reserved to support the upper rock body. Some mining methods used nowadays cause damage to the stability of the pillars to a certain extent, so it is crucial to study and prevent the damage to the pillars. In this paper, the stability of the pillars is investigated by comparing the damage caused by the conventional point pillar method and the point pillar boundary pre cracking and blasting method in the west section of the Dahongshan Copper Mine in the middle of the 180th section of the 360 Bl44 quarry. The findings show that the damage depth of the conventional point pillar mining is about 1. 47 m, while the damage depth of the point pillar boundary pre cracking blasting is about 1. 21 m, and the damage impact of the point pillar boundary pre cracking blasting on the neighboring pillars is smaller than that of the conventional point pillar mining. The change of sound velocity of the rock body in the point pillar boundary pre cracking blasting area is 9. 02%, which is smaller than the change of sound velocity of the rock body in the conventional point pillar blasting area by 14. 65%. [ABSTRACT FROM AUTHOR]

The paper focused on the acid leaching technology of pyrite and pyrolusite, leaching parameters like H2SO4 concentration, mass ratio of pyrite and pyrolusite, reaction time, liquid to solid ratio, and reaction temperature were investigated, and the most suitable leaching condition was determined. On this basis, the experimental study on pre oxidation cyanide leaching of the flotation gold concentrate from a refractory gold mine in Gansu province was carried out The results showed that under the parameters of mass ratio of pyrite and pyrolusite was 1; 6, H2SO4 concentration was 100 g/L, liquid to solid ratio was 6, reaction temperature was 90 °C, and the leaching time was 12 h, Mn extraction rate of 76.0% was achieved. Meanwhile, the oxidation rate of pyrite can reach 88. 2%, and 85. 4% gold leaching rate was obtained after cyanidation of pre oxidized residue. [ABSTRACT FROM AUTHOR]

Copper slag beneficiation tailings are the tailings produced after copper smelting slag is treated by beneficiation process, which is rich in Fe, Ni, Cu, Cr and other valuable metals* In this paper, the metallization pellet of copper slag beneficiation tailings obtained after reduction and roasting in rotary kiln is taken as the research object, and 80 kVA AC furnace is used to carry out the melting experiment, and the effects of different process conditions such as reductant, co solvent and settling time on the recovery rate of Fe, Ni, Cu and other metals under the rated conditions are investigated, as well as the migration law of the main elements in the melting process of the metallization pellet. The results shown that the metallization pellet of the copper slag beneficiation tailings obtained by rotary kiln reduction can effectively recover the valuable metals such as Fe and Cu, and obtain high grade ferroalloy products by melting in an electric furnace under the process conditions of 1 530 °C, 18 % of melting agent rate, and 30 min of settling time, and the recovery of Fe is more than 95%, and the recovery of Ni and Cu reaches 38% and 71 % respectively. Elemental direction analysis shown that S, Pb, As and other impurity elements will enter the alloy to varying degrees. [ABSTRACT FROM AUTHOR]

As a preparation material for important components such as conductive springs and interconnect connectors, the large scale industrial preparation method and heat treatment process of Cu Ti alloy are still the key areas that urgently need to be developed and promoted in the current copper alloy field. In the present paper, Cu Ti alloys with Ti content of 1%, 4. 5 % and 10% were prepared by aluminothermic reaction, which has the advantages of simple process, environmental protection, energy saving and low cost, and the comprehensive properties of the alloys were further regulated by solid solution and aging treatment. The results show that the Ti elements in the aged Cu l%Ti and Cu 4.5%Ti alloys are mainly in the state of solid solution with only a small amount of smaller precipitates, while there are a large amount of precipitates in the aged Cu 10% Ti alloys. With the increase of Ti content, the electrical conductivity of the alloys shows a significant decrease trend, while the hardness and strength show the opposite trend. For the alloys with the same composition, compared to the solid solution state, the conductivity first slightly decreases and then increases with aging time. After aging at 450 °C for 4 h, the conductivity of all three component alloys is higher than that of the solid solution state alloys* After aging at 450 °C for 2 h, the hardness, strength and elongation of Cu l%Ti and Cu 4. 5%Ti alloys obtain the maximum values, and the hardness and elongation of Cu 10 % Ti alloys also obtain the maximum values, while the yield and the tensile strength of Cu 10%Ti alloys show slightly decreasing trend with aging time. [ABSTRACT FROM AUTHOR]

Aiming at the problem that it is difficult to recover valuable zinc from industrial solid wastes such as zinc oxide tailings and Grain slags, this paper prepares high-purity zinc oxide micro powder by using carbothermal reduction and oxidation method with local industrial zinc-containing solid wastes as raw materials. The thermodynamic process of the reaction between zinc silicate and carbon reduction in the zinc-containing slag was analyzed by a combination of thermodynamic calculations and experimental studies through HSC Chemistry. The effects of carbon allocation, roasting temperature, roasting time and CaF2 on zinc yield during zinc silicate reduction were discussed, and the results showed that the catalytic effect was most significant at 1000 ℃~1100 ℃ when CaF2 was used as a catalyst. The optimum process conditions were obtained: the zinc yield reached 97.44% at a temperature of 1100 °C, a holding time of 40 min, a carbon content of 20 wt% and a CaF2 addition of 5 wt%. Structural and compositional analyses of the volatilized product showed that the physical phase was hexagonal zinc oxide crystals with a particle size of 2~4 um and a purity of 99.47%. [ABSTRACT FROM AUTHOR]

In order to more accurately predict the trend of vault subsidence in underground mine ramps and control the prediction accuracy to ensure mine safety, this paper proposes a whale optimization algorithm (WOA) enhanced neural network method for vault subsidence prediction. The main steps are as follows: firstly, the original data is processed using the method of adjacent point median smoothing, and the processed monitoring data is used as input samples for training and testing BP and Elman neural networks; then, the WOA is used to optimize the initial weights and thresholds, and finally, different model output predictions are obtained. Simulation experiments show that the BP and Elman neural network models optimized by the whale optimization algorithm can more accurately predict the vault subsidence compared to before optimization. The determination coefficient of the WOA-Elman model is 0.948, which is superior to the WOA-BP model at 0.941, but the running time of the WOA-Elman model, 671.214 s, far exceeds that of the WOA-BP model, 307.226 s. The WOA-Elman model consumes more training time for a small improvement in accuracy, significantly reducing training efficiency. Combined with the analysis and comparison of measured values and predicted values from engineering examples, the WOA-optimized BP neural network exhibits more efficient and accurate vault subsidence prediction capability. [ABSTRACT FROM AUTHOR]

The aluminum electrolytic waste cathode was leached with sulfuric acid to obtain a leaching solution containing valuable elements such as Na, Li, Al, and F. The leaching solution has recovery value, but it is accompanied by serious secondary pollution. In this paper, the cryolite crystallization method is used to remove fluoride twice, and the lithium is recovered after fluoride removal. When the reaction pH=9, n(Al):n(F)=1:6, the reaction temperature was 50 °C, the reaction time was 90 min, and the crystal seed addition was 0.8 g/L. The residual fluorine concentration in the solution was 48 mg/L, the one-time fluoride removal rate was 98.15%, and the lithium removal rate was 1.38%. After the secondary fluoride removal, the concentration of fluorine in the solution was 49 mg/L, the secondary fluoride removal rate was 85.12%, and the lithium removal rate was 2.13%. After two fluoride removals, the total removal rate of fluorine was 99.38%, and the total removal rate of lithium was 1.31%. The purity of the prepared Li2CO3 is greater than 99.5%. [ABSTRACT FROM AUTHOR]

Low-potassium molybdenum products have a wide range of applications in electronics, medical and other fields, and ammonia leaching has a very important impact on the production of low-potassium molybdenum products. In order to better control the amount of potassium released in the ammonia leaching process to reduce the pressure of potassium reduction in the subsequent process, this paper analyzed the potassium release law and gave its kinetic model and control method by conducting a one-factor simulation experiment on the influencing factors of potassium release in the ammonia leaching process of molybdenum bakery sand. The results show that the temperature, solid-liquid ratio and molybdenum roasting sand grain size have great influence on the release of potassium, and the optimal conditions for ammonia leaching are: temperature 30 ℃, solid-liquid ratio 1:3, molybdenum roasting sand grain size ranging from 150~178 μm, and ammonia concentration of 20%. In addition, Ca element is more favorable for potassium removal in the ammonia leaching process, while Na element is not favorable for potassium removal in the ammonia leaching process. After slaked lime has a certain effect on potassium removal in water leaching, the effect of sodium carbonate on potassium removal in water leaching is not obvious, so the addition of slaked lime in molybdenum roasted sand water leaching process is favorable to the production of low-potassium ammonium molybdate. Molybdenum roasted sand ammonia leaching process in the early stage of potassium release speed is faster, and the late stage of the speed becomes slower, the Avrami equation can be obtained to better simulate the process of potassium release in the early stage and late stage of ammonia leaching, and the kinetic equation of the ammonia leaching process was determined. [ABSTRACT FROM AUTHOR]

In order to enhance the hot hardness and toughness of HSS, NbC particles reinforced ASP2080 HSS composites were prepared in this paper by powder ball milling (carbide and metal powders) plus vacuum sintering process. The microstructure and mechanical properties of NbC/ASP2080 HSS composites were characterized and analyzed using equipment such as XRD, SEM, EDS, and universal tensile testing machine. The results show that: the addition of NbC does not change the phase structure of composites, and with the increase of NbC content, the matrix grain size of heat-treated composites decreased significantly; heat treatment can significantly improve the hardness, flexural strength and impact toughness of composites; the hardness, flexural strength and impact toughness of heat-treated composites with the increase of NbC content are increased and then decreased trend. The heat-treated composites with 4% NbC content have the best overall performance, with an average grain size of 6.52 μm, and the hardness, flexural strength and impact toughness of 71.7 HRC, 825.3 MPa, and 6.75 J/cm2, respectively. [ABSTRACT FROM AUTHOR]

The blasting vibration signal in the mine environment contains a lot of high frequency noise, which seriously affects the authenticity of the blasting vibration signals In this paper, targeting the phenomenon that there is a lot of high frequency noise in the blast signals, using blast vibration data from an open pit mine in Yunnan as a research object, this paper proposes research on noise reduction of blast vibration signals based on adaptive WOA VMD MPE blast vibration signal denoising method. WOA optimization algorithms are used to process blast vibration signals from three mines, and the optimal parameter combination of the VMD algorithm K、q is found, which is broken down via the VMD algorithm, and the IMF components with MPE above 0. 6 are removed in order to obtain the effect of the noise reduction. The results show that it can be seen that the signal to noise ratio of the vibration waveforms optimized by the WOA VMD algorithm is the highest, which is 15. 23,25. 51, 27. 2 respectively, and the mean squared error is the lowest, which is 8. 51, 8. 73,5. 91, respectively. Compared to the EEMD and CEEMD algorithms, the signal to noise ratio of the WOA VMD algorithm is increased by 56% and 44%, and the mean squared error is decreased by 46 % and 42 %, respectively. It has a better noise reduction effect than the EEMD and CEEMD algorithms. It can better remove high frequency noise and retain the original vibration waveform information from the blast, thus verifying the universality of the algorithm. [ABSTRACT FROM AUTHOR]

A normal cloud model for slope stability analysis based on AHP Critic method is proposed to address the randomness and fuzziness issues in stability evaluation of open pit mine slopes. Analyze five representative, relevant, quantifiable, and easily obtainable slope stability evaluation indicators, including density, cohesion, friction angle, slope height, and slope angle. Firstly, the subjective and objective weights of the five indicators are obtained based on the AHP and Critic methods. Then use the multiplication synthesis normalization method to obtain the comprehensive weight Secondly, the above indicators are divided into five grades. Then, calculate the cloud feature parameters for each indicator at different levels* Using Python software, calculate membership based on measured slope data and cloud feature parameters. Calculate the comprehensive determination of slope stability level using the obtained comprehensive weights and membership degrees. Determine the slope stability level based on the principle of maximum membership. Finally, the model was applied to a limestone mine in Yunnan. The prediction results obtained from the model built in this paper are compared with the calculation results of the strength reduction method and the limit equilibrium method used by the two software* The results indicate that this method is feasible and the prediction results are accurate, which can provide reference for the stability analysis of the mine slope. [ABSTRACT FROM AUTHOR]

When the theoretical research results of the laboratory are applied to the production practice, it is often found that there are obvious differences between them, which greatly decrease the practicability of flotation research, especially pure mineral research. The reason for the difference between the theoretical research and practical application results lies in the complexity of the flotation process, it is not only necessary to pay attention to the chemical principle of the chemicals adsorption on the mineral surface, but also to comprehensively consider and analyze the chemical environment of flotation (solution conditions and associated minerals). In recent years, the proposed coordination chemical model of mineral flotation, together with the continuous development of solution chemistry theory, provides the possibility to realize the goal of theoretical research guiding practical production. In this paper, the application examples of coordination chemical model of mineral flotation, solution chemical calculation and extended DLVO theory in the study of mineral flotation mechanism at home and abroad are collected and summarized. Introduction and comments are given regarding the theoretical content, calculation process and application examples of the three theories, so as to provide a reference for the future flotation research. [ABSTRACT FROM AUTHOR]

The recovery of valuable metals from roasted cyanidation tailings by step separation is of great significance to the sustainable development of metallurgical industry. In this paper, gold, copper and zinc were extracted from cyanide tailings by first order acid leaching, secondary reduction roasting magnetic separation to recover gold bearing iron concentrate and third order flotation to recover gold, the comprehensive recoveries of gold, copper, zinc and iron from cyanide roasting tailings were 63. 07%, 80. 5%, 70. 31% and 80. 64% respectively. The technical method can effectively solve the technical problem of comprehensive recovery of gold, copper, zinc and iron from roasting cyanidation tailings, and realize the high value and resourceful utilization of roasting cyanidation tailings, at the same time, the roasting cyanide waste is converted into secondary high value resource, which solves the common technical problem in metallurgical industry. [ABSTRACT FROM AUTHOR]

The removal of impurities in molybdenum calcine has become a new challenge for enterprises due to the cancellation of pickling. Whether the impurity minerals can be converted into soluble ions in the roasting process is of great significance for the current washing. In this paper, the traditional methods such as laser particle size analyzer and X Ray Diffraction(XRD) were used to analyze the particle size, pore size and elements of molybdenum concentrate. Combined with Mineral Liberation Analyzer(MLA) and Factsage thermodynamic software, the changes in the occurrence forms of impurity elements during the production of molybdenum calcine were studied, and the specific path of impurity minerals transforming into soluble ions was explored. The results show that there are nanoscale pores in both molybdenum concentrate and molybdenum calcine, which will prevent washing and impurity removal. As the main insoluble impurities, aluminum potassium minerals have a great influence on the production of high purity molybdenum products, and most of them exist in the form of alkaline minerals with large molecular weight. In the roasting process of molybdenum concentrate, K containing minerals such as muscovite and orthoclase can be partially converted into soluble ions such as K十 and AF十, and then removed by washing. Humidification improves the degree of conversion of orthoclase into soluble ions during roasting and is beneficial to the removal of impurities during washing. [ABSTRACT FROM AUTHOR]

In the context of "dual carbon", the aluminum smelling industry is facing enormous pressure to reduce emissions. This paper takes an electrolytic aluminum enterprise n Shanxi province as an example to calculate the carbon emissions of each ink of the enterprise in 2021 and identify the mam factors that affect the carbon emission reduction of the electrolytic aluminum industry. Using scenario analysis method to predict the adjustment of power structure, upgrading of low-carbon electrolytic aluminum technology, and application of recycled aluminum in Shanxi province from 2021 to 2030. Establish a multi factor analysis model for electrolytic aluminum carbon emissions, and explore the impact of various control variables on reducing carbon emissions per ton of aluminum for enterprises in benchmark and policy scenarios. The results show that changes in the power structure have the greatest contribution to the greenhouse gas emissions reduction of the enterprise, with emissions reductions accounting for 31. 63% of the total emissions under the 2030 baseline scenario and 40. 66% of the total emissions under the policy scenario; When coupled with changes in power structure and the proportion of recycled aluminum, the emission reduction effect Is most significant, with the emission reduction accounting for 67.82% of the total emissions in the 2030 policy scenario; Under the three coupling situation, the carbon emissions of the enterprise gradually tend to zero. [ABSTRACT FROM AUTHOR]

In the process of mining, there are rocks affected by cyclic disturbances, which have significant effects on the mechanical properties of rocks. To understand the loading rate effect of rocks under different cyclic loading and unloading methods,this paper carries out constant lower Unit cyclic loading and unloading, variable lower Unit cyclic loading and unloading tests on sillimanite specimens with different loading rates, comparatively analyzes the deformation characteristics, the energy evolution law and the destructive characteristics of the specimens under the two cyclic loading and unloading methods with different loading rates. The test results show that the peak strength and residual deformation of the specimen have different acceleration rate effects, but the peak strength is improved compared with the conventional uniaxial compression test; WITH the increase of the loading rate, the input energy, elastic energy and dissipation energy of the specimen in all stages show an increasing trend, but with some differences in the form of manifestation; the destruction of the specimen and IS morphology show the acceleration rate effect, and the degree of destruction is intensified with the increase of the loading rate. [ABSTRACT FROM AUTHOR]

In recent years, lithium metal plays an irreplaceable role in the preparation of all-solid-state lithium batteries and aluminum-lithium alloys; but the cost of lithium metal production is still a problem that needs to be solved by production enterprises. Therefore, this paper optimizes the production process and equipment from the perspective of reducing energy consumption by using Solid Works three-dimensional modeling of the electrolyzer structure as well as ANSYS simulation and simulation software to simulate the thermal field of the electrolyzer and calculations, resulting in the optimal design scheme. Its production electrolysis efficiency can reach 91%, energy consumption is below 35 kWh/kg, chlorine extraction and lithium collection device can run automatically, the concentration of extracted chlorine gas is 90%, the lithium collection efficiency can reach more than 80%, and the amount of lithium is more stable. The equipment can be better put into industrialized production, meet the needs of enterprises to reduce production costs, and promote the development of molten salt electrolysis of lithium metal industry. [ABSTRACT FROM AUTHOR]

This paper presents the calculation and analysis of the important mononuclear complexes in the Se-H2O system. Based on the thermodynamic data of S0 + ΔfG0 + ΔfH0 and CP of each reaction substance at standard state, the dominant region distribution of the dissolved species ni Se(-II):H2O, Se(IV):H2O and Se(IV)-H2O systems were calculated at different pH values under the temperature range of 298-573 K. Combined with the equilibrium thermodynamic data of the oxidaton and reduction reactions of Se containing substances at different temperatures, the potential-pH diagrams of the Se-H2O system at 298, 373,473 and 573 K were constructed. It was found that both H2Se and H2SeO3 could exist stably in high acid content solution, while H2SeO4 could only exist in high-temperature and high add content solution. At 298 - 573 K,Se could exist stably in aqueous solution. In the range of 298 - 473 K, H2SeO3-, HSeO3 and SeO32- could be directly reduced to elemental Se. Therefore, by controlling a certain pH value and potential, Se could be removed from the solution by precipitation in the form of elemental Se. With the increase of temperature, the stable region of H2O decreased, and the region of Se, which exssted in the sold phase, also gradually decreased. In the liquid phase, the stable regions of H2SeO3-, HSeO3- and SeO32- with Se(+IV) continued to increase. With the increase of temperature, the oxidation potential of elemental selenium oxidized to Se (IV) and further to Se(VI) decreased slightly, and the oxidation reaction could be easier to carry out. [ABSTRACT FROM AUTHOR]

Aiming at the problems ol slow filling elliciency and low and unstable sand discharge concentration in the traditional vertical sand silo working mode, a continuous high-concentration and stable sand discharge working mode is proposed, and the maintenance ol sand storage height is the key to this working mode. In this paper, the centrilugal test is used to investigate the lunctional relationship between the underllow concentration and the sand storage height, and then the static settlement test is used to obtain the feeding parameters, and the hydro dynamic software is used to simulate and analyze the sand storage process ol the vertical sand storage,to verily the feasibility ol the functional relationship, and the dynamic mesh technology is used to simulate and monitor the sand discharge concentration, overllow concentration and sand surlace height change ol sand discharge process with dilierent storage heights, and to investigate the optimal sand storage height, and to provide a comprehensive solution to the problem. The simulated monitoring ol sand discharge concentration and sand surlace height changes during sand discharge at dillerent storage heights using dynamic grid technology is used to comprehensively investigate the optimal sand storage height, which provides an important reference lor the study ol continuous sand discharge Irom vertical sand silo. The results show that:there is no significant dillerence between the numerical simulation and the lunctional relationship, and the lunctional relationship between the underllow concentration and the sand storage height is feasible； 11. 8m is the optimal sand storage height lor the vertical sand silo to continuously discharge sand with high concentration and stability. [ABSTRACT FROM AUTHOR]

Aiming at the problems ol high soluble silicon in calcine,easy agglomeration in Iluidized bed boilers and dillicult solid-liquid separation in the roasting process ol high silicon zinc concentrate. This paper is based on the on-site roasting production process parameters, the effects ol low and high temperature roasting on the soluble silicon content in calcine are studied, and the roasting process ol Iluidized bed boilers is simulated using MatCal software. The results show that under the same roasting conditions, with the increase ol roasting temperature, the acid soluble silicon in calcine increases, and the dillerence ol 1. 03% was obtained between low-temperature roasting and high-temperature roasting. When the soluble silicon content in calcine is above 3, 18 %, certain problems will appear ,including turbidity ol thickener supernatant, the dillicult liltration for underllow pulp alter low acid leachings high cobalt content in the impurity removal ol purilied solution and so on. Alter MatCal simulation,the theoretical air consumption, the average air volume ol low-temperature roasting and the average air volume of high-temperature roasting are 50 361. 328 m$/h, 47 102, 8 m3/h, and 48 005. 7 m$/h respectively. However,the average air volume in actual roasting is low,thus it is necessary to raise the air material ratio ol the Iluidized bed boilers. [ABSTRACT FROM AUTHOR]

As a new technology, ultrasonic wave has a great application prospect in the lield ol metallurgy. This paper introduces the ultrasonic and its mechanism ol action, elaborates the application ol ultrasonic technology in the hydrometallurgy industry, summarizes the research status ol ultrasonic simulation technology and the prospect of the ultrasonic simulation technology. The application ol ultrasonic auxiliary technology in hydrometallurgy is analyzed, in order to provide relerence for the better application ol ultrasonic auxiliary technology in hydrometallurgy. [ABSTRACT FROM AUTHOR]

As an important technical lorm ol electrochemical energy storage,lithium ion battery is still limited in practical application due to the possibility ol thermal runaway. Therefore，it is necessary to understand the variation rule ol battery temperature field alter thermal runaway trigger and analyze the factors allecting temperature change. In this paper, ANSYS FLUENT is used to simulate the lithium ion battery, and the internal thermal dillusion law ol the battery is studied by simulating the temperature field change ol the battery under dilierent charge and discharge Iluctuation power input caused by the instability of the generator end. The thermal diffusion law is analyzed by simulating the temperature field alter the thermal runaway triggered by local short circuit in lithium ion battery. The results show that the temperature and wall heat Ilux ol the lithium-ion battery fluctuate with the input current. When triggered by local short circuit, the rate ol thermal runaway extending lengthwise along the electrode is greater than that ol radially spreading outwards. Increasing convective heat transfer coefficient can effectively reduce the rate and amplitude ol battery temperature rise,reducing the possibility ol thermal runaway ol battery. The study ol thermal dillusion law provides a basis for predicting thermal runaway in practical application, improving safety, and improving battery cooling technology. [ABSTRACT FROM AUTHOR]

The extensive generation of coal dust during underground mining operations has resulted in adverse working conditions, significantly elevating the occurrence of safety accidents, and posing health risks to coal miners. This paper explores the synergistic enhancement and wetting behavior of a selected composite surfactant solution when combined with four distinct types and concentrations of inorganic salt solutions. Various experimental methods were employed to investigate the interactions and wetting characteristics. The findings demonstrate that a composite solution consisting of 0. 9 mol/L NQ2SO4 with a combination of SDBS and Triton X 100 at a ratio of 4 : 1 exhibits the most favorable synergistic effect. Furthermore, a quantitative evaluation of the wetting performance parameters of the coal was based on the results obtained. It was observed that the spreading coefficient correlates positively with Na2SO4 concentration, while both adhesion work and surface free energy show a negative correlation with Na2 SO4 concentration, which suggests that the introduction of inorganic salt anions restores the absorbability of kaolinite, increasing the number of hydrophilic sites on the coal surface and enhancing the adsorption density of anion nonionic composite surfactants. Consequently, the wetting performance of the solution is significantly improved. [ABSTRACT FROM AUTHOR]

In order to realize the comprehensive recovery of alunite from copper tailings and reduce the content of sulfuric anhydride in alunite tailings so that it does not affect the preparation of micro powder, this paper takes a copper tailings in Fujian as the research object, and carries out a process mineralogical study on copper tailings samples by means of chemical analysis, mineral auto analyzer(BPMA), etc., and focuses on the identification of the main phase composition, embedding characteristics and particle size distribution of quartz, alunite, geode, sericite and sulfuric anhydride in the tailings. The results show that SO$ in copper tailings accounts for 5.04%, TS content accounts for 1. 91 %, alunite is commonly associated with quartz, diorite and sericite in the form of leaching, and some of them can be seen to contain fine grained pyrite and its association. Sulfuric anhydride is mainly in alunite, and part of sulfuric anhydride is dispersed in diorite, quartz and sericite. Recovering alunite from copper tailings samples, the theoretical grade of sulfuric anhydride in the concentrate is 38. 22%, and the theoretical recovery rate is about 94%. On the basis of process mineralogical research, we propose to adopt the process of 11 desliming desulfurization alumina flotation11, the process structure is 11 one coarse, one sweep, two fine11 flotation flow, and get the alumina with SO$ grade of 20. 14% and SO$ recovery of 53. 36%. Concentrate, and the content of sulfur anhydride in the tailings meets the requirements for the preparation of micropowder. [ABSTRACT FROM AUTHOR]

In recent years, image processing technology has been widely used in the field of intelligent sorting ol ore, but the current intelligent sorting image processing algorithms still have limitations in terms of accuracy, algorithm elliciency and versatility. The contour extraction of X-ray sorting ore image is one ol the important prerequisites for intelligent sorting. The characteristics ol mineral distribution, content, size and morphology in the ore are determined according to the contour inlormation, so as to optimize the ore sorting process and improve the recovery rate and economic benelits ol minerals. In this paper, the imaging principle and image noise characteristics ol X-ray intelligent sorter are analyzed, the image preprocessing method is summarized, the principle and network structure ol the classic canny algorithm and the HED, DeepEdge and U-Net contour extraction algorithms of deep learning are introduced, and the advantages and disadvantages ol the algorithm are analyzed. Finally, the existing problems ol X-ray intelligent sorting ore image processing algorithm and the future research locus are proposed. It provides a relerence lor the mineral contour extraction research ol X-ray intelligent sorting image processing system. [ABSTRACT FROM AUTHOR]

Three types ol ZnS based organic amine nanocomposites, ZnS (n-BA), ZnS ♦ (HMD)工, and ZnS (DETA) j, were synthesized via solvothermal method. The photocatalytic perlormance ol the three materials were tested under the conditions of ethanol as sacrificial agent and H2 PtCl6 as cocatalyst, and their photocatalytic perlormance was analyzed based on their bandgap values and structural characteristics by gas chromatograph. The results show that the bandgap values ol ZnS ♦ (n-BA), ZnS ♦ (HMD)工, and ZnS (DETA)工 composites are 3. 66, 3. 91, 3. 85 eV, respectively. In addition, this paper successfully achieved the coupling of photolysis ol aquatic hydrogen and selective oxidation ol sacrilicial ethanol. C C coupling ol organic compounds was achieved on ZnS nanocomposites, and the high-value additional product 2, 3-butanediol was selectively synthesized using sacrilicial ethanol. At the same time, the hydrogen production rate remained at a high level. Among the three composite materials, ZnS (n-BA) with the smallest bAiidgEp width and particle size has the highest photocatalytic hydrogen production ability, with an average hydrogen production rate ol 22. 48 mmol/(h • g). In terms ol product selectivity, ZnS • (n-BA)j; also has the highest content of 2,3-butanediol, which can reach 88. 72%. As the composite material with the best hydrogen production elliciency and product selectivity among the three, ZnS ♦ (n-BA) is also at an advantageous level ol stability, and is expected to provide certain relerence value in the study of photocatalytic hydrogen production perlormance ol new nanocomposites. [ABSTRACT FROM AUTHOR]

With the increasing demand ol spacecraft lor 3D-printing metal materials, spacecraft propose higher requirements for reliability of 3D-printing metal materials. Based on the analysis results of service environment in spacecraft, the characteristics of 3D-printing materials and the application lunctions in spacecraft, this paper established the properties evaluation technical index system, designed the technical route of scheme and delined the properties index evaluation method Irom the perspective ol 3D-printing metal raw materials, typical components and products. Finally, a technical scheme lor reliability evaluation ol 3D-printing metal materials for spacecraft was lormed, which provided technical support for the sale and reliable application ol 3D-printing materials in the aerospace lield. [ABSTRACT FROM AUTHOR]

The C02 emission of iron and steel industry is large, and the urination of metallurgical solid waste such as steel slag is difficult. Steel sag carbonation material has good stability and durability, but its low tenia strength and easy cracking limit the application in the construction field. In this paper, still lag is used as carbonization raw material, polypropyiene fiber is used as reinforcement material, and carbonization curing is used to develop and prepare fiber reinforced steel lag carbonization material. Based on the compressive strength, flexural strength and carbonation degree of steel lag carbonation materials, the influence of polypropylene fiber content on the mechanical properties and carbonation consolidation properties of still lag carbonation materials were studied by means of micro-analysis methods including thermogravimetric and mercury intron method. [ABSTRACT FROM AUTHOR]

In order to explore the affluence of empty hole on the propagation of biasing cracks, an empty hole blasting damage model is established by comb mg ANSYS/LS-DYNA finite dement software. The equation of stress distribution n the rock mass near the empty hole is deduced theoretically, and the Influence of empty whole effect on the fracture mechanism and crack propagation is analyzed. The results show that the free surface effect of empty hole will cause the sudden Increase of impact pressure and the change of seismic velocity near the empty hole, which leads to the phenomenon of "falling" of rock at the blasting surface. The shock velocity at the back surface of the empty hole is significantly smaller than that at the front surface, which indicates that the empty hole has a good effect of pressure relief and shock reduction. By comparing the analytical solution of the impact pressure and the radius of the fracture zone with the numerical calculation results it is found that the error rate of the impact pressure is 11.81%, and the error of the rams of the fracture zone is only 9.49%, which proves the accuracy of the simulation results in this paper. [ABSTRACT FROM AUTHOR]

In the process of sac leaching process, the stable control of pH value is the key factor to affect the production cost and product quality. A trapezoidal long short-term memory model predictive control (TLSTM-MPC) method integrating process characteristics is proposed to solve the problems of the complex mechanism of continuous stirred-tank reactor (CSTR), large fluctuation of Met conditions and large image of reaction. Firstly, the key factors affecting the pH value stability control are analyzed. Combined with the cascade characteristics of CSTR, a trapezoidal long short-term memory network structure (TLSTM)moll characterizing the physical characteristics of CSTR is proposed, which makes the perdition moll have better physics interpretability. Secondly, the TLSTM-MPC algorithm was proposed to solve the problems of Met condition fluctuations and large image in the reaction process, and particle swarm optimization algorithm was used for optimization solution. Finally, the filled operation data of a large- scale leaching process is used to verify. The results show that the overshoot and adjustment time of this algorithm are reduced by 51. 2% and 57. 4% compared to traditional control methods tespectivlly,and it can quickly stabilize the pH value under Met fluctuations. The method proposed in this paper has potential engineering practical application value for the stable and high-quality production of the leaching process. [ABSTRACT FROM AUTHOR]

The leaching of spent lithium-ion battery (LIBs) cathode materials with non-aqueous systems has received widespread attention. In this paper, a binary non-aqueous system of glycerin(Gly)-formic acid(FA)and a ternary non-aqueous system of Gly-FA-choline chloride (ChCl) were used for the leaching of LiCoO2 cathode materials. The effects of leaching time, leaching temperature and liquid-to-solid ratio conditions on leaching rates were investigated. The results indicated that the addition of ChCl was able to significantly improve the leaching rates of the metals. Under the optimal conditions of time 210 min, temperature 120 °C and liquid-solid ratio 100 mL/g, the ternary non-aqueous system achieved leaching efficiencies of 99.77% and 89.09% for Li and Co respectively, higher than the 67.94% and 67.11% for the binary non-aqueous system. The leachate was analyzed by UV-Vis and FT-IR spectroscopy to reveal the leaching mechanism. The results showed that FA was able to reduce Co3+ to Co2+ in LiCoO2. However, Co2+ was present in different forms in the two non-aqueous systems, where the binary system was present as a hexa-coordination and the ternary system as a tetra-coordination. [ABSTRACT FROM AUTHOR]

TiAl intermetallic compound alloy is an important high-perlormance material, and its microstructure is ol great signilicance to the study ol the characteristics ol lamellar growth behavior and microstructure evolution. In the experiment ol high-temperature phase transition precipitation growth, the accurate identilication and positioning ol its microstructure plays a vital role. This paper aims to solve the problems ol low accuracy and strong subjectivity in identifying the microstructure through human observation by applying computer vision technology to the intelligent identilication ol Ti-48Al-2Cr-2Nb alloy high-temperature precipitated phase structure. Alter model selection, data set production, parameter and conliguration selection, and training result analysis, the target detection experiment was completed. The experimental results show that the proposed target detection model lor precipitated phase structure can achieve more than 80% in terms ol precision, recall and average precision, among which mAP can reach up to 88%. Meanwhile, the method has high precision and high elliciency, and the detection speed ol a single image is 17ms. Therefore, this method shows broad application prospects in the identilication and location ol Ti-48Al-2Cr-2Nb alloy high temperature precipitated phase structure. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge ol accurately measuring the conductivity ol highly conductive thin metal loils using existing testing methods. To this end, we analyzed the ellect of metal loil thickness on electric lield reflection At the interlace between ultra-thin metal loils and air, and the distribution ol internal electric lield and surface impedance ol these loils, as well as the coil impedance in eddy current testing systems. Subsequently, we proposed a new non-destructive testing method lor measuring the conductivity ol metal foils thinner than 100 which relies on using two loils of different thicknesses to eliminate the disruptive effects of electric lield rellection at the interlace. The results demonstrate that this new method produces testing deviations of only about 3% in silver, copper, and copper-chromium-zirconium loils, which is signilicantly lower than the error rate ol the commonly used, improved stacked loil method(about 20%). Moreover, employing an appropriate thickness design further reduces the testing deviation to 2%. The new method has a conductivity testing range of 80% 110% IACS. This study is expected to contribute to the improvement ol standardized high-conductivity ultra-thin metal loil testing protocols, which are vital in scientific research and industrial applications. [ABSTRACT FROM AUTHOR]

The oxygen bottom blowing copper process has the advantages of high speed, low energy consumption and high matte grade. The copper content in bottom blowing smelting slag is as high as 5%.After slag separation treatment, the copper content in tail slag is ≥0.30%,and the copper recovery rate is low. After magnetic separation of tailings, the total iron content in iron concentrate is less than or equal to 50%, which cannot be used and accumulates in large quantities, polluting the environment and wasting resources. In this paper, a new additive is used to promote the growth and settlement of copper and iron components in slag by using the physical thermal and high chemical activity characteristics of slag, which creates conditions for subsequent slag separation. The industrial test results show that the copper content of tailings is 0.21% lower than that without additive after adding additive to 12 m³ slag ladle, and the total iron content in iron concentrate is ≥51%,which reaches the standard of iron concentrate. This method opens up a new way for the comprehensive utilization of copper melt slag in bottom blowing. [ABSTRACT FROM AUTHOR]

Acid mine drainage(AMD) is one ol the most serious environmental pollution, mainly caused by pyrite oxidation. AMD treatment mainly has two ways of end-treatment and source control, end-treatment technology cannot lundamentally solve the problem ol pollution, so Irom the source control ol pyrite oxidation is the lundamental way to control AMD. The main source control technologies include covering method, sterilization method and surface passivation method. In this paper, on the basis ol introducing the causes ol AMD, various surlace passivation techniques are reviewed. The research status ol organosilane, carrier-microencapsulation, sell-healing and other technologies is summarized. The advantages and disadvantages ol dilierent methods are analyzed, and the future research direction is proposed in view ol their shortcomings. It provides relerence lor solving the problem ol pyrite oxidation and realizing ellective control of AMD pollution. [ABSTRACT FROM AUTHOR]

In order to further master the tunneling technology ol mining small coal pillars along the gob and improve the resource recovery rate. According to the specific production geological conditions, this paper analyzes the distribution characteristics and inlluence ol small coal pillar support stress in small coal pillar roadway excavation, working lace advance and secondary mining by means ol ground pressure monitoring and numerical simulation. The results show that: 1)During roadway excavation, the pressure in the first 50 meters ol the roadway is large, especially the two sides of the roadway move closer, and the maximum distance ol the two sides is about 200 mm. 2) During the roadway excavation stage and the mining inlluence period, a 5 m coal pillar is lelt between the return air chute and the upper transportation chute, lorming a large stress concentrathe maximum vertical stress in the coal pillar is 21. 38 MPa. The vertical stress in the coal wall behind the Iront of the work is about 30 MPa, the stress concentration lactor is about 3, the inlluence range is about 84 m, and the maximum vertical stress ol the coal pillar is 41 MPa. 3) Allected by the secondary mining, the stress in the coal pillar is basically about 40 MPa, which changes little compared with the primary mining, while the peak stress appears in the triangle area in Iront ol the working lace, up to 57. 4 MPa, indicating that this area is the locus ol prevention and control during the mining ol the working face. The results of ground pressure monitoring and numerical simulation are relatively consistent, which further proved the reliability ol the research results. [ABSTRACT FROM AUTHOR]

Relining and modilying A356 alloy is one ol the important ways to improve its mechanical properties. In this paper, A356 alloy melt was treated with a new Al-Ti-La refiner and Al-10Sr modifier, and the ellect ol holding time on the microstructure and mechanical properties ol as-cast A356 alloy was studied. The results show that when the holding time is 15 min and the A356 alloy is treated with Al-Ti-La reliner and Al-lOSr modifier, the secondary dendrite arm spacing ol a-Al in the as-cast A356 alloy is reduced from 31. 10 pm to 15. 56 pm, which is reduced by 49. 96%, and the eutectic Si morphology is changed Irom coarse needle Hake to line short rod and granular. With the improvement ol cr Al and eutectic Si phase morphology, the tensile strength ol as-cast A356 alloy increased Irom 169. 67 MPa to 216. 33 MPa, increased by 27. 50%, the elongation increased Irom 4. 47 % to 10. 53 %, increased by 135. 57%, and the Vickers hardness ol the alloy also increased Irom 56. 37 HV to 62. 03 HV, increased by 10. 04%. The fracture mode changes from trans granular fracture to intergranular fracture, and the plasticity and toughness ol the alloy are obviously improved. [ABSTRACT FROM AUTHOR]

In this paper, micro-crack initiation and propagation behavior ol aluminum alloy 7050-T7651 with dilferent pre-corrosion time are investigated via in-situ SEM tensile tests. Based on the in-situ and online SEM observation, the ellect of corrosion damage on the micro-crack behavior is discussed. Experimental results show that: with the corrosion time increases, the density ol corrosion pits increases, while the bearing capacity ol the specimen decreases; rough surlaces ol the specimen notch and corrosion pits are the preferred location lor micro-crack initiation, the number ol micro-crack increases with the extension ol corrosion time. The main crack dominates the failure process is generated by the coalescence ol micro-cracks from notch and adjacent corrosion pits. When corrosion damage is relatively light, crack branching occurs due to the existence ol corrosion pits near the tip ol the main-crack; when corrosion damage is relatively heavy, multiple micro-cracks induced by corrosion pits will joint with the main-crack and allect the main-crack propagation direction and path. Shear stress plays an important role in the crack propagation process, and the cracking mode belongs to T / TT mixed fracture mode. [ABSTRACT FROM AUTHOR]

Impact damage will destroy the structure of uranium tailings dam, and bring potential harm to the safety of people and property around and downstream. In this paper, the impact simulation experiment of uranium tailings dam is carried out through the self-developed horizontal impact test bench to study the damage characteristics of the dam and the radon emission law of the dam damage under the progressive loading of impact velocity. The experimental results show that the impact damage to the dam body is mainly manifested by the development of single main cracks on the surface and the penetration failure. The penetration depth increases with the increase of impact speed, and the change speed of the penetration depth after the penetration failure of the laterite layer increases. The cumulative growth rate of radon concentration before the penetration of laterite layer is faster than that after the penetration, and the law of penetration depth and overall radon exhalation rate presents a slow rise(OA) - rapid rise(AB) - stable trend(BC). The relationship between the penetration depth and the radon reduction coefficient shows a rule of rapid decline to a stable trend, and the variation of the radon reduction coefficient is only 2. 94% in the 3-7 cm penetration interval after the laterite layer penetration. The results can provide a reference for the study of safety and stability of uranium tailings dam. [ABSTRACT FROM AUTHOR]

Based on the technical regulations of pollution source census and the contents and requirements of the census system, this paper puts forward the key points and methods of micro audit, industry audit and macro audit of rare earth industry pollution source census data. The micro-audit includes the verification of the accuracy of the census form code and the filling data, and the verification of the pollutant emission data. According to different processes and raw and auxiliary materials of rare earth industry, as well as pollution control technology, the industry audit determines whether the amount of pollutants produced, discharged and removal efficiency are reasonable. According to the development status and regional distribution of rare earth economy, the pollutant emission data can be reviewed from a macro perspective. The review of the data of the pollution source census object of the rare earth industry can provide a better reference for the evaluation of the pollution source census data. [ABSTRACT FROM AUTHOR]

8011 aluminum alloy is a widely used cast rolling aluminum alloy. The solid liquid ratio and Al-Ti-B addition amount in the melting process are key factors affecting its properties. In this paper, the effects of solid liquid ratio(25%,30%,35%,40%) and Al-Ti-B master alloy addition(0. 18%,0. 20%,0. 22%) on the microstructure and mechanical properties of 8011 aluminum alloy were studied via optical microscope (OM), transmission electron microscope(TKM) and mechanical property tests. The results show that the higher the addition of Al-Ti-B master alloy, the finer and more uniform the grain size distribution of 8011 aluminum alloy at the same solid-liquid ratio; At the same addition amount of Al-Ti-B master alloy, the higher the solid-liquid ratio is, the smaller the grain size of 8011 aluminum alloy is, but it is easy to lead to grain agglomeration; When the solid-liquid ratio is 40% and the addition amount of Al-Ti-B master alloy is 0. 22%,8011 aluminum alloy has the best grain refinement effect and mechanical properties. Its tensile strength can reach 107 MPa, elongation can reach 12. 4%,and hardness is 36. 73 HV. [ABSTRACT FROM AUTHOR]

The feeding trolley is an important part of the semi-autogenous mill, and the service life of the feeding trolley chute liner directly affects the operating rate of the semi-autogenous mill, and it is very necessary to extend the service life of the chute liner. The discrete element method is mainly used for equipment simulation of ore particle size reduction process, and the simulated equipment includes jaw crusher, cone crusher, semi-autogenous mill, ball mill and other main equipment, as well as auxiliary equipment such as mine silo, belt machine and transfer chute. In this paper, taking the chute liner of a semi-self-mill feeding trolley as an example, the discrete element method is used to analyze and optimize the chute liner structure, and the reasonable chute liner structure is designed based on the site usage, and the wear mechanism of the chute liner is analyzed with reference to the discrete element analysis, and the material selection of the chute liner is optimized. The optimal combination of structure and material selection is adopted to improve the service life of the feeding trolley chute liner. [ABSTRACT FROM AUTHOR]

The preparation technology of micron spherical metal powder has become a common problem in the fields of chip, medical diagnosis, and 3D-printing. In this paper, micron spherical gold powder was prepared by hydrometallurgy process, and high-purity conductive gold ball was prepared by plasma spheroidizing method. The high-purity and highly dispersed gold powder was prepared with the self-made Au-99. 999% as raw material, hydrazine hydrate as reducing agent and PVP as diluent, and the reduction potential was controlled at 1 692 ~ 1 002 mV, 5N micron conductive gold spheres for semiconductor chips are obtained by gas flow crushing and plasma spheroidizing. At present, this method has realized industrialized production of 10 kg, preliminarily solved the problem that the conductive gold ball for domestic chip packaging was monopolized by other countries, and made an important contribution to improving China's chip R & D industry chain, especially the research and development of electronic grade gold raw materials. [ABSTRACT FROM AUTHOR]

In this paper, the medium and high-temperature sealing behavior of the coatings made by ultrasonic arc spray technique was studied. The results showed that the low-temperature S100 sealing agent got obvious burning at the medium temperature of 400 °C, resulting in the direct exposing of the surface and internal through-pores in the gas environment, which caused heavy oxidation of the coating. The oxidation rate of the coatings was much lower when using the medium-temperature S400 sealing agents. In the water-cooling thermal shock testing at 400 °C, heavy spallation took place in the coating sealed by S100 while the coating sealed by S400 performed better resistance. In the testing conditions at 700 °C, the high-temperature S700 sealing agent well filled the pores in the coating, which improved the oxidation resistance. It was found that the medium and high-temperature sealing agents performed good stability at the increased temperatures and effectively covered the coating surface or filled the internal pores. Therefore, the inward diffusion of the out-coming oxygen was hindered, and the oxidation resistance and the spallation resistance of the coatings were improved. [ABSTRACT FROM AUTHOR]

AlSi10Mg has been widely used in aerospace and other fields due to its low density and high strength. By combining with selective laser melting (SLM) technology, high quality and high complexity components can be rapidly produced. The effect of printing direction and subsequent HIP treatment on the microstructure and mechanical properties of AlSi10Mg formed by SLM were studied in this paper. It is found that different printing directions leave different molten pool characteristics on the finished product, and the ductility of the test piece decreases with the increase of printing angle. Hot isostatic pressing eliminates the characteristics of the molten pool, but it also transforms the reticulated Si phase into granular precipitation phase, reduce the tensile strength and improve the plasticity, and the ductility still declines with the increase of the printing angle. [ABSTRACT FROM AUTHOR]