Table of Content

22 November 2020, Volume 20 Issue 11

Previous Issue    Next Issue

Contents

Cover and contents

Chin. J. Process Eng.. 2020, 20(11):  0. 

Asbtract ( )   PDF (870KB) ( )  

Related Articles | Metrics

Reviews

Application of ultrasonic intensification in hydrometallurgy leaching process

Jiewen YAN Dean PAN Bin LI

Chin. J. Process Eng.. 2020, 20(11):  1241-1247.  DOI: 10.12034/j.issn.1009-606X.219357

Asbtract ( )   PDF (1532KB) ( )  

Related Articles | Metrics

In recent years, with the continuous scarcity of primary mineral resources, the decline in mineral levels, and the increase in secondary resources, how to efficiently recover precious metals from raw materials such as primary ore, concentrates or secondary resources is both an environmental issue and an economic issue that needs to be resolved. Hydrometallurgy, as a method of efficiently recovering metals, is leaching raw materials in acidic or alkaline solutions, transferring the metals to the solution in the form of ions, and then using extraction, solid?liquid separation and other means to recover the metals. Among them, leaching, as an important process in hydrometallurgy, has the advantages of high comprehensive recovery rate of valuable metals, higher recovery rate of low-grade ore than pyrometallurgy, and low operation difficulty. It has been widely used in metallurgy. At the same time, the leaching process has the disadvantages of high requirements on the concentration of the leaching solution, long reaction time, and slow reaction rate. To overcome the above disadvantages, it is an effective way to improve the existing metal hydrometallurgical process through various assisted leaching technologies. Among them, by adding ultrasonic to the external field, using ultrasonic cavitation mechanical effects and thermal effects to strengthen the reaction process together, it has the characteristics of improving the solid surface structure, uniform leachate system, and optimizing the reaction history. Compared with the traditional leaching process, the leaching time can be shortened, the leaching rate can be increased, and the amount of reagents can be reduced. The entire leaching process can be performed at room temperature, which greatly reduces the energy consumption. This work summarized the ultrasonic cavitation and its mechanism in the leaching process, highlighted the characteristics and advantages of the ultrasonic enhanced leaching process, put forward the limitations of ultrasonic itself, and prospected its future development in this field.

Flow & Transfer

Experimental study on flow field and heat transfer performance of insert-spiral vertical upstream tube

Deqi PENG Chunxia YANG Jianping ZHANG Tianlan YU Weibiao YE Hao LI

Chin. J. Process Eng.. 2020, 20(11):  1248-1256.  DOI: 10.12034/j.issn.1009-606X.219363

Asbtract ( )   PDF (1609KB) ( )  

Related Articles | Metrics

Through the particle image velocimeter (PIV) flow field experiment combined with heat transfer experiments, the effects of structural parameters such as spiral pitch, wire diameter and median diameter ratio of insert-spiral vertical upstream tube on the flow field and heat transfer performance were studied under different Reynolds number. The results showed that the insert-spiral can effectively disturb and mix the fluid in the tube, and a number of longitudinal vortexes were formed in the tube, and the vorticity of liquid increased near the wall of the tube, which was beneficial to the enhancement of heat transfer. When the Re number was the same, the average flow velocity v, Nu number and the comprehensive heat exchange performance (PEC) in the tube increased with the increase of the wire diameter, and increased with the decrease of the median diameter ratio. As the pitch increased, all three parameters tended to increase, and began to decrease when the pitch was greater than 20 mm. The resistance coefficient f of the fluid in the tube decreased with the increase of the wire diameter and the pitch, and increased with the increase of the median diameter ratio. In general, when the Re number was lower, the comprehensive heat transfer effect was best with a pitch of p=20 mm, a wire diameter of e=1.6 mm, and a median diameter ratio of D/d=0.75.

Feasibility study on intermittent operation of solution dehumidifier

Zhijia HUANG Heng ZHOU Feifei ZHUO

Chin. J. Process Eng.. 2020, 20(11):  1257-1264.  DOI: 10.12034/j.issn.1009-606X.219379

Asbtract ( )   PDF (613KB) ( )  

Related Articles | Metrics

In order to solve the problem of air with liquid in the solution dehumidifier, a method of intermittent operation of the solution dehumidifier was proposed, which separated the air supply from the solution spray. The numerical model of dehumidifier was established, and the feasibility of the model was verified by comparing the experimental data and simulation data. Based on the model, the influence of operation parameters and design parameters of intermittent solution dehumidifier on dehumidification performance was studied and the operation effect of different air supply systems was simulated. The results showed that the static liquid holding capacity should be controlled in the range of 4.575~6.100 kg/kg and the packing height should be controlled in the range of 0.45~0.75 m, the intermittent operation method was more suitable to deal with the air with low temperature and high humidity (such as 20℃ and RH95%), which can solve the problem of traditional solution dehumidification with liquid. The dehumidification effect of the parallel staggered air supply system was the best, during the operation, the dehumidification rate was more than 5 g/kg, which can supply air continuously and meet the dehumidification demand.

Thermal performance analysis of seawater desalination system based on liquid gap heat pump membrane distillation

Qiyu ZHANG Le TONG Chen YUE

Chin. J. Process Eng.. 2020, 20(11):  1265-1272.  DOI: 10.12034/j.issn.1009-606X.219350

Asbtract ( )   PDF (705KB) ( )  

Related Articles | Metrics

A novel brine solution concentration system based on the heat pump membrane technology was integrated to improve the membrane flux as well as reduce the consumption of cooling water. This proposed system was simulated by the Aspen Plus platform. After experimentally verifying the system simulation model, influences from the feed liquid temperature, temperature at permeate side and feed flow rate on the overall thermal performance indices of the system were studied. The results showed decreasing temperature at permeate side improved the permeability and decreased of the coefficient of performance (COP), and the change of temperature at permeate side played a great effect on the coefficient of performance under the fixed condition of the low temperature at permeate side. With increase of the temperature at permeate side, an optimal temperature value was obtained to maximize the water production ratio and minimize the energy consumption per ton of water, and the maximal water production ratio was 3.42, the minimal energy consumption per ton of water was 463 MJ/t under the working condition in this research. Besides, as the feed liquid temperature increased, the optimal temperature at permeate side increased. As the feed flow rate rised, permeability and coefficient of performance went up, while the energy consumption of tons of water rised and the water production ratio reduced. Moreover, when the feed flow rate was less than 3 L/min, the energy consumption of tons of water and the water production ratio reduced sharply as the feed flow rate increased. When the feed liquid temperature was 50℃, the feed flow rate increased from 1.5 L/min to 3 L/min, the value of GOR (Gained Output Ratio) decreased by 33.5%, while the rise of flow rate from 4.5 L/min to 6 L/min only caused GOR decrease by 10.6%.With increase of the permeation side temperature, an optimal temperature value is obtained to maximize the water production ratio and minimize the energy consumption per ton of water, and the maximal production ratio is of 3.42, the minimal energy consumption is of 463 MJ/t under the working condition in this research. Besides, as the feed temperature increases, the optimal permeation side temperature increases. As the feed liquid flow rises, permeability and energy efficiency ratio go up, while the energy consumption of tons of water rises and the water production ratio reduces. Moreover, when the feed liquid concentration is less than 3L/min, the energy consumption of tons of water and the water production ratio reduce sharply as the feed liquid flow increases.

Power characteristic of adhesive particles mixing in a stirred tank

Hao XIONG Yuyun BAO Jing WANG Ziqi CAI

Chin. J. Process Eng.. 2020, 20(11):  1273-1280.  DOI: 10.12034/j.issn.1009-606X.220040

Asbtract ( )   PDF (693KB) ( )  

Related Articles | Metrics

Power consumption is an important parameter in the design and scale-up of stirred tank reactors. The effects of relative liquid volume, rotational speed and fill level on power consumption were experimentally investigated in a cylindrical stirred tank. The discrete element method (DEM) and Hertz-Mindlin with JKR model were used to investigate the effect of the adhesion force of particles with different relative liquid volumes on the power consumption. Results showed that the power consumption first increased and then decreased with the increase of the relative liquid volume, and reached a maximum when the relative liquid volume was 0.0162. With the increase of the rotational speed, the power consumption increased faster, but the rotational speed influence index on the power consumption decreased first and then increased with the increase of the relative liquid volume. The maximum power consumption was about 1.8 times of the power consumption with saturated particles. A new method for indirect measurement of cohesion between particles was proposed, and a linear relationship between power consumption and cohesion was obtained.

Reaction & Separation

Effect of different particle sizes of modified fly ash on phosphate adsorption performance

Jianlin YANG Yuao ZHANG Shuhua MA Xiaohui WANG

Chin. J. Process Eng.. 2020, 20(11):  1281-1288.  DOI: 10.12034/j.issn.1009-606X.219382

Asbtract ( )   PDF (2547KB) ( )  

Related Articles | Metrics

Excessive discharge of phosphorus in wastewater leads to increasingly serious water pollution. The fly ash was chemically modified into a hydrated calcium silicate adsorbent to explore its absorption effect on the phosphate. XRD, SEM, BET specific surface area and so on were used to characterize the adsorbents before and after particle size classification. Then the adsorption performance of the adsorbents with different particle sizes on phosphate was studied, and the adsorption mechanism was also investigated. The results showed that the chemical compositions of the adsorbents with different particle sizes showed significant segregation, and the pore structures were also significantly different. Specifically, compared to other adsorbent particles, the particles with the size of 50?75 μm had a higher content of calcium and silicon, lower content of aluminum, iron, and magnesium and thereof higher content of hydrated calcium silicate companied with aluminum-containing tobermullite crystals. The increase of calcium ions made it easy to combine with more phosphate to form a precipitate. At the same time, this particle had a higher specific surface area and more porosity and the loose and porous structure provided more active sites for calcium ions. When used as an adsorbent to adsorb phosphate, the saturated phosphorus adsorption capacity of the particles with the size of 50?75 μm can reach 17.1 mg/g, which was 19.58% higher than that of an unclassified adsorbent.

Treatment performance of ammonia-nitrogen wastewater containing high salt by copper-loaded resin

Ruoyu YIN Yunnen CHEN Caiqing HE Chen LIU

Chin. J. Process Eng.. 2020, 20(11):  1289-1295.  DOI: 10.12034/j.issn.1009-606X.219368

Asbtract ( )   PDF (947KB) ( )  

Related Articles | Metrics

The ligand exchange adsorption method uses the ability of transition metal ions to form complexes. By supporting the transition metal on a certain adsorbent carrier, and then using the special complexation between the target pollutant and the transition metal, the target pollutant is adsorbed on the adsorbent. A ligand-loaded adsorbent was prepared by supporting Cu2+ with a resin as a carrier for the high-salt ammonia?nitrogen wastewater, and the ammonia nitrogen was selectively adsorbed onto the resin by the coordination of Cu2+ and ammonia nitrogen. Ammonia nitrogen is adsorbed to the resin in two ways: one is through the combination of NH4+ and OH? to generate NH3, which is coordinated with Cu2+on the resin; the other is that NH3 reacts directly with Cu2+ on the resin, so that ammonia nitrogen can be adsorbed. In this work, resins with different functional groups were selected as supports, modified with Cu2+, and their performance in treating high-salt ammonia nitrogen wastewater was studied. On the basis of selecting the best copper resin, the effects of pH, Na+ concentration, resin dosage and reaction time on the adsorption of ammonia nitrogen by copper resin were studied. In order to further explore the process of coordination adsorption, SEM, EDS and adsorption kinetics model were used to characterize the copper resin before and after ammonia nitrogen adsorption. The results showed that Cu2+ could combine with chelating resin D751 stably and exhibited salt tolerance and good adsorption effect of ammonia?nitrogen under wide pH value. Under the conditions of room temperature (25℃), pH=11, Na+ concentration of 4 g/L, resin dosage of 8 g/L, reaction time 60 min, the removal rate of ammonia?nitrogen by D751 copper-loaded resin was 34.8%. After adsorption of ammonia nitrogen by D751 copper resin, crystal structure substance appeared on its surface, which may be copper ammonia complex. In addition, the adsorption kinetics of D751 copper resin for ammonia nitrogen containing high saline was in good agreement with quasi-second-order kinetic model.

Process & Technology

Flotation mechanisms of rutile in synergistic system composed by sodium oleate and sodium benzohydroxamide

Mingbao LIU Wanzhong GUO Siyu TIAN Mei CHEN

Chin. J. Process Eng.. 2020, 20(11):  1296-1303.  DOI: 10.12034/j.issn.1009-606X.219332

Asbtract ( )   PDF (879KB) ( )  

Related Articles | Metrics

The flotation behaviors of rutile in combined regent system of sodium oleate (SO) and sodium benzohydroxamide (BHA) were studied via pure mineral flotation test. The interactions between reagents, reagents and mineral as well as the effect of the reagent combination on rutile flotation had been investigated through several measurements, including Zeta potential, contact angle, surface tension, UV diffuse reflectance spectroscope, concerning the interface chemistry properties at gas?liquid interface and solid?liquid interface. The results indicated that the reagent addition sequence influenced rutile recovery significantly and the combined use of reagent had a distinct positive-synergistic effect under different pH values. The flotation recovery of rutile and synergistic effect index followed the order: adding BHA prior to SO>pre-mixed before adding>adding SO prior to BHA. The electron-rich double bond in SO may interact with the electron-deficient benzene ring in BHA to form diverse interionic/intermolecular association complexes. The amount of the complex presented as the optimum configuration on mineral surface was critical for the synergistic effect of reagent combination and rutile flotation behavior. The effect of reagent combination on flotation recovery rate agreed well with that on the rutile bandgap width according to the UV diffuse reflectance spectroscope spectrum of rutile sample after interacted with the reagent combination under various conditions.with the electron-deficient benzene ring in BHA to form diverse interionic association complexes. The amount of the complex presented as the optimum configuration on mineral surface is critical for the synergistic effect of reagent combination and rutile flotation behavior. The effect of reagent combination on flotation recovery agree well with that on the rutile bandgap width according to the UV diffuse reflectance spectroscope spectrum of rutile sample after interacted with the reagent combination under various conditions.

Optimization on bottom blowing+side blowing lead smelting for utilizing of lead?silver leaching residues

Ze YANG Yaru CUI Yu HAO Lü ZHAO Zhengmin WANG Tingliang ZHANG Junxue ZHAO Fan ZHU

Chin. J. Process Eng.. 2020, 20(11):  1304-1312.  DOI: 10.12034/j.issn.1009-606X.219376

Asbtract ( )   PDF (1081KB) ( )  

Related Articles | Metrics

The comprehensive recovery and complementation of lead and zinc resources is the main developing trend for lead and zinc enterprises. This work aim is to solve the problems, such as lack of heat in oxidizing smelting, difficulty in process control of slag, poor stability of reducing slag, etc, emerged in the bottom blowing-side blowing lead smelting system mixed with lead?silver leaching residues in Hanzhong Zinc Industry Co., LTD. On the basis of comprehensive evaluation of the original process, thermodynamic analysis on dominant region and phase diagram of melting process were calculated, the slag properties were determined, and subsequently, optimizing process based on regulation of slag system were put forward. The results showed that the temperature of oxidizing smelting was raised to 1050℃ and the reduction smelting was lowered to 1250℃, though adjusting heating mode of the bottom blowing furnace from sulfur to bituminous coal and pyrite as auxiliary. The direct lead-smelting process mixed with lead-containing residues can be operated smoothly though controlling reduction smelting slag, in which FeO/SiO2 mass ratio was 1.2?1.6, CaO/SiO2 mass ratio was 0.4?0.6, and ZnO≤20wt%. After process optimization, the ratio of oxygen to material decreased from 120 Nm3/t to 110 Nm3/t, and the proportion of lead?silver leaching slag mixed in charge materials increased to 24wt%. In the meanwhile, the dust content of smelting flue gas in oxidation and reduction smelting reduced by 13.47% and 15.82%, respectively, and the cost of crude lead reduced by 10.63% as a result.

Investigation on the spreading dynamics of metal powder based on discrete element method

Wenguang NAN Yiqing GU

Chin. J. Process Eng.. 2020, 20(11):  1313-1320.  DOI: 10.12034/j.issn.1009-606X.220210

Asbtract ( )   PDF (2229KB) ( )  

Related Articles | Metrics

The use of Additive Manufacturing (AM) is increasing at a fast rate in wide ranging industries, aerospace, medical technology, transport and energy. One of the manufacturing methods used in this field is based on powder processing, but its major bottleneck is associated with the quality of particle spread layer in the powder spreading process, as its underlying particle dynamics remains unknown, which is sensitive to the type of spreader and the cohesive interaction between particles. Here, the particle dynamics in the powder spreading process for a gas-atomised metal powder was explored by discrete element method (DEM), using the most realistic physical and mechanical properties of the particles. The velocity and trajectories of particle within the heap, and the quality of the particle spread layer, were compared in the blade and roller spreading processes. Their sensitivity to the cohesive interaction between particles were also explored. The results showed that compared to blade spreading, there were several velocity bands in cascading style and particle convection within the heap in the roller spreading process, due to the rotational motion of the roller spreader. Before the formation of particle spread layer in roller spreading, the particles needed to climb upward and slip downward along the edges of heap, resulting in longer trajectories of particles. With the increase of particle surface energy, the total particle volume of spread layer was reduced in both blade and roller spreading. Compared to blade spreading, the total particle volume of spread layer in the roller spreading was smaller and more sensitive to particle surface energy. This could be attributed to the formation mechanisms of particle spread layer, i.e. the ability of particles within the heap entering into the gap region between the rough base and spreader, and the drag effect of particles by the spreader in the gap region.

Materials Engineering

Evolution process of FeSi₅Cr_5.5/SiO₂ core-shell structure during fluidized bed chemical vapor deposition

Zhaoyang WU Chen XIAN Jixiang JIA Xi'an FAN Xiangwei LIAO Mingya ZHANG

Chin. J. Process Eng.. 2020, 20(11):  1321-1328.  DOI: 10.12034/j.issn.1009-606X.219371

Asbtract ( )   PDF (1280KB) ( )  

Related Articles | Metrics

The formation time and evolution process of FeSi5Cr5.5/SiO2 core-shell structure during the fluidized bed chemical vapor deposition were studied with tetraethoxysilane as the precursor of SiO2 insulation and FeSi5Cr5.5 spherical particles as the substrate. The microscopic characteristics of particle samples before and after deposition were characterized by X-ray diffraction, field-emission scanning electron microscopy and X-ray photoelectron spectroscopy. The magnetic hysteresis loops and resistivity of particle samples before and after deposition were measured using vibrating sample magnetometer and four point probe instrument. The results showed that it took 30 minutes at a minimum to completely convert from FeSi5Cr5.5 particles to FeSi5Cr5.5/SiO2 core-shell structure particles according to the three-dimensional island nucleation model during the fluidized bed chemical vapor deposition. There were four and five categories of silicon and oxygen electron structure in the FeSi5Cr5.5/SiO2 core-shell structure. The resistivity of FeSi5Cr5.5/SiO2 core-shell structure particles increased three and four orders of magnitude than that of FeSi5Cr5.5 particles, while the values of saturation flux density declined slightly.

Simulation analysis of flow field and thermally induced damage mechanism in ceramic membrane filter

Kaikai SI Yunfa CHEN Qingzhu LIU Rui XIONG Guangchao SUN Kaiqi LIU

Chin. J. Process Eng.. 2020, 20(11):  1329-1335.  DOI: 10.12034/j.issn.1009-606X.220010

Asbtract ( )   PDF (1222KB) ( )  

Related Articles | Metrics

Thermal stability of ceramic membranes for high-temperature gas purification is the key to long-term stable operation of ceramic membrane filters. Based on the standard k?? turbulence model and porous media model, the gas flow in the ceramic membrane filter was numerically simulated. The distribution characteristics of the gas velocity field, pressure field and temperature field in the device during the steady-state filtration phase were studied. The temperature field changes in the device before and after the non-steady-pulse cleaning were compared, and the mechanism of the ceramic filter material damage caused by thermal-mechanical coupling during pulse cleaning was studied by quantitative analyses. The results showed that the model established by the simulation can more realistically reflect the field distribution characteristics of the gas in the whole process of hot gas filtration and pulse cleaning. During the steady-state filtration stage of the hot gas, the gas velocity was higher at the inlet and outlet pipes compared to those in the dust-containing chamber and the clean air chamber. The gas velocity in the filter tube gradually increased along the axis of the tube, while the gas pressure gradually decreased. The filter temperature did not change with the change of position. During the non-steady-state pulse cleaning stage, the temperature field of the gas near the blowback inlet formed a low-temperature region, which was distributed in an almost elliptical shape in the axial section of the tube. It should be emphasized that the temperature at the inner wall of the tube first decreased and then rose along the axial direction. However, the temperature of the gas in the tube gradually increased and the temperature in dust-containing chamber was almost unchanged. At a distance of 0.0664 m from the top of the ceramic tube, the material was subjected to the greatest thermal stress of 2.8 MPa, which was the most vulnerable position during the pulse cleaning process.

Study on the preparation and performance of Mn-doped ultra-low density proppants

Junmei FAN Dan LIU Xianguang WANG Bingzhong SHI Fangli YUAN

Chin. J. Process Eng.. 2020, 20(11):  1336-1343.  DOI: 10.12034/j.issn.1009-606X.220180

Asbtract ( )   PDF (1597KB) ( )  

Related Articles | Metrics

Under the condition of ensuring the high strength of the proppant, reducing the apparent density of the proppant as much as possible is the key to the development of shale gas clean water fracturing technology. In this work, low-grade bauxite and micro-SiO2 were used as the main raw materials, and water glass, nano-SiO2 and manganese oxide were used as auxiliary materials. The ultra-low density proppants were prepared by plasma dynamic sintering and later high-temperature sintering methods. The effects of different manganese oxide doping and different sintering time on phase composition, bulk density, apparent density and crushing rate at 69 MPa of proppants were discussed. And based on the classic PKN fracturing model, the settlement and migration of ultra-low density proppant in simulated fractures were studied. The results showed that an ultra-light proppant with an apparent density of 1.639 g/cm3 and a breakage ratio of 8.91% under 69 MPa was successfully prepared. The optimal manganese oxide doping content was 7.5wt%, and the optimal sintering temperature and sintering time were 950℃ and 2 h. Ultra-low density proppant migrated a longer distance in the horizontal direction than conventional proppants, and the distribution of proppant inside the fracture was relatively more uniform, which can meet the requirements of clean water fracturing for medium and deep oil wells.

Environment & Energy

Effect of ferric ion concentration on atmospheric scorodite synthesis in As(V)-Fe(II)-Fe(III) system

Fulian YUE Cailong SHEN Guangji ZHANG Chao YANG

Chin. J. Process Eng.. 2020, 20(11):  1344-1352.  DOI: 10.12034/j.issn.1009-606X.219381

Asbtract ( )   PDF (2745KB) ( )  

Related Articles | Metrics

The present study is focused on the synthesis of scorodite (FeAsO4?2H2O) at 95℃ and initial pH 1.5 under atmospheric pressure. In particular, the effects of initial ferric ion concentration of the solution on the arsenic removal rate and the scorodite formation were investigated in As(V)?Fe(II)?Fe(III) system. The experimental results showed that the well crystalline scorodite was formed through oxidizing ferrous ions by air stream when there was no additional ferric ion in the solution, but only 24.3% of arsenic could be removed and the United States Environmental Protection Agency's Toxicity Characteristic Leaching Procedure tests showed that the arsenic leaching concentration of scorodite was more than 5 mg/L, higher than the arsenic concentration limit set by the national standard. In all the experiments with the additional ferric ions, it was found that there was amorphous ferric arsenate formed in the heating process. The amorphous ferric arsenate was found to converted to crystalline scorodite in 8 h if the initial Fe(III)/As(V) molar ratio was not higher than 1.6. However, the crystallinity of scorodite decreased with the increase of additional ferric ion concentration, the arsenic leaching concentration of solid products decreased and the arsenic removal rate of the solution were improved. The results of the TCLP leaching test showed that at the initial Fe(III)/As(V) molar ratio of 0.8 and 1.6, the arsenic leaching concentration of the formed solid products were less than 5 mg/L, which could meet the emission standards, so that the solid products may be considered to be stable for safe disposal. Nevertheless, if the initial Fe(III)/As(V) molar ratio was higher than 1.6, the amorphous ferric arsenate could not convert to crystalline scorodite after 8 h. The arsenic removal rate decreased and the amorphous ferric arsenate was unstable for high arsenic leaching concentration. Experimental results suggested that adding appropriate ferric in solution containing arsenic and ferrous could contribute to forming stable scorodite and promoting arsenic precipitation.

The diffusion law and distribution characteristics of high drop dust

Yihua CHEN Mingyan GU Song CHEN Lianmeng GE

Chin. J. Process Eng.. 2020, 20(11):  1353-1362.  DOI: 10.12034/j.issn.1009-606X.220008

Asbtract ( )   PDF (1039KB) ( )  

Related Articles | Metrics

In the process of ore drawing in high pass, a strong impact airflow will be formed, which will cause dust diffusion and serious underground environmental pollution. The effective treatment of the pollution has always been the focus of underground ventilation and dust removal. In this work, the diffusion law and distribution characteristics of dust in the process of ore pass drawing are explored by means of the combination of similar experiment and numerical simulation. By changing the experimental conditions of ore drawing quality, ore particle size, chute sealing degree, water content and other factors, the air flow size and dust concentration distribution under different conditions were researched. The CFD-DPM coupling method was used to simulate the gas?solid two-phase flow in the process of ore unloading, and the temporal and spatial distribution characteristics of gas flow and dust concentration were studied. The results showed that the maximum dust concentration and wind speed increased with the increase of ore drawing quality, and decreased with the increase of particle size and airtight degree of ore pass. The higher the water content was, the smaller the dust concentration was, but the wind speed had no obvious changed. Moreover, the key factor affecting dust concentration was water content, followed by the airtight degree of ore pass, ore drawing quality and ore particle size. In the process of ore drawing, the collision between ore particles played a dominant role, and the particle flow presented a transverse distribution.