Dust Suppression Research Articles

A Combined Electrodialysis and Coal Dust Suppression System for Acid Mine Drainage Treatment and High Mechanical Hydrogel Dust Suppressant Generation

A Combined Electrodialysis and Coal Dust Suppression System for Acid Mine Drainage Treatment and High Mechanical Hydrogel Dust Suppressant Generation

Suppression Efficiency for Dust from an Iron Ore Pile Using a Conventional Sprinkler and a Water Mist Generator

Re-suspension of iron ore dust presents a constant hazard in the working environment within steel production plants. Herein, the optimal operating parameters for maximum dust suppression efficiencies through a water mist generator and a conventional sprinkler for particulate matter (PM) originating from an iron ore pile measuring about 2 m in height and with a stacking angle of about 30° are investigated. The effects of operating parameters including wind velocity, spray angle, and mode of water supply on dust suppression efficiencies are evaluated. Size differentiated PM samples were collected from the upwind and downwind locations of the iron oral pile and the dust suppression efficiencies are determined. The operating parameters with the highest dust suppression efficiencies using the water mist technology are low spray angle, low wind velocity, and intermittent water supply, while those for water sprinkling technology are high spray angle, low wind velocity, and intermittent water supply. The average dust suppression efficiencies for Total Suspended Particles (TSP), PM10, and PM2.5 for the mist generators are 80.9%, 77.9%, and 76.9%, respectively, whereas those for the conventional sprinklers are 76.4%, 72.9%, and 72.7%, respectively. For the surfactant to water ratios of 0.024, 0.022 and no surfactant, the ratio of 0.024 had the highest dust suppression efficiencies for TSP, PM10, and PM2.5 at 90.9%, 89.5%, and 89.0%, respectively. Insights from this investigation can be applied to optimize the dust suppression methods to ensure economical consumption of water and energy.

Surface adhesion barrier management in dust suppression at mining enterprises

Surface adhesion barrier management in dust suppression at mining enterprises

Synthesis and Properties of Coal Dust Suppressant by Microalgae Oil Extraction

Synthesis and Properties of Coal Dust Suppressant by Microalgae Oil Extraction

Optimization of Organic Mulches Thickness Improves Soil Moisture Retention under Controlled Conditions

Organic mulch can improve the moisture, chemical composition, dust, and dust suppression of soil, and beautify the environment. In view of the rapid evaporation rate and serious loss of soil water in tropical areas, this paper explored the effect of organic mulch materials with different thickness on the increase of soil water retention rate and the improvement of soil water loss caused by evaporation. Rubberwood sawdust (RWS), rubberwood bark (RWB), coconut fiber (CF), and Mulch (MC) were selected as the mulching materials. Field experiment and laboratory experiment were performed, and soil-moisture content and temperature were continuously monitored. However, from the daily measurement of water content at constant conditions (29°C ± 0.2°C, 74% ± 1% air RH) in the laboratory experiment, the results of variance analysis (ANOVA) showed that there was no significant difference between the soil-water content of covered samples and bare soil (P > 0.05). In the field experiments, the analysis of variance indicated significant differences in the soil-moisture content owing to the effect of the covering material (P

New Type of Sawdust-Based Dust Suppressant During Tunnelling and Underground Space: Preparation, Characterization and Engineering Application

New Type of Sawdust-Based Dust Suppressant During Tunnelling and Underground Space: Preparation, Characterization and Engineering Application

Research on the Dust Suppression Effect of Three Types of Baffles on the Particle Flow Horizontal Projectile Falling Process in Transverse Airflow

Industrial progress is the source of social development. As one of the important links in the industrial production process, industrial particulate transportation systems such as coal, cement, mineral materials and food transportation cause a large number of dust diffuse problems, which have become the pollution source of the deterioration of the environment quality in the workplace. In the production process, the initial velocity of the conveyor belt makes the particle flow form a horizontal projectile motion, which causes the dust pollution and transverse airflow often further aggravates the dust diffusion. Firstly, the author verified the applicability of Discrete Phase Model by using experimental result. Then, this paper studies the control effect of dust emission in the particles flow horizontal projectile fall process with different types baffle and different baffle positions under transverse airflow. The results show that the semicircular baffle has a better dust suppression effect, followed by the V-shaped baffle, the straight baffle is the worst. The semicircular and V-shaped baffles are moved closer to the particles source out, the better the dust suppression effect. The dust suppression effect of the straight baffle gradually improves as the distance increases, and reaches the best at a distance of L=1 m. The research results provide a theoretical basis for ventilation dust removal design of industrial particulate transport systems.

Risk Assessment of Natural Radionuclides and Radon Gas in the Artisanal and Small-Scale Gold Mine of Buhemba, Tanzania

Currently, the mining industry in Tanzania faces significant challenges including the presence of radionuclides in the working environment. In this work, different indices were applied to assess the health risk of people living and working in the study area. The radiation hazards in the studied mining areas are compared with the recommended local and international guidelines. The health risk and mitigation measures due to radioactive elements exposure to mine workers and people dwelling in the mines is established. The hyper pure germanium detector (HPGe) was used for radioactivity analysis. The radon gas levels were measured using the Alpha Guard radon monitor. The results on radioactivity; mean effective dose; annual gonadal equivalent and absorbed dose; radium equivalent; internal and external hazard indices; alpha and gamma indices; and the radon gas revealed high values in mining areas compared to the control area. However, some of the levels of radionuclides along with their hazard indices are lower than the recommended international limits. The mitigation measures which include dust suppression using water spray and the use protection gears such as masks and gloves are recommended. The present study recommends follow up and further studies in the ASGM subsector.

Influence of the Branched Structure of Polyoxyethylene Units in Nonionic Surfactants on the Wettability of Anthracite: A Combined Modeling and Experimental Study

Coal dust is a significant concern to the safety of coal mine operations. The wettability of coal can be effectively altered by adding surfactants to water. The development of high-efficiency dust suppressants is hampered by a lack of understanding of the microscopic interaction process between coal dust and surfactants. In this investigation, the influence of the branched structure of the polyoxyethylene unit in nonionic surfactants on the wettability of anthracite surfaces was evaluated by combining the modeling study and experimental research. The macromolecular model of Jincheng anthracite with 55 different components (C7730H3916O133N123S25) was constructed. Lauryl polyoxyethylene ether C12(EO)20 and Tween 20 were selected. The simulation results showed that due to the branched structure of polyoxyethylene, the surface of anthracite after adsorption by Tween 20 is more hydrophilic. Further analysis found that the adsorption configuration of Tween 20 is that the hydrophilic head group covers the hydrophobic tail chain, while the adsorption configuration of C12(EO)20 is that the hydrophobic tail chain covers the hydrophilic head group. The network structure formed by Tween 20 is relatively loose, and the surface is rougher. The network structure formed by C12(EO)20 is denser. Water molecules have a higher aggregation degree near Tween 20 and stronger permeability, and more hydrogen bonds are formed. The existence state of carbon and oxygen elements on the surface of modified coal was analyzed by XPS experiment, which confirmed the adsorption structure obtained by molecular simulation.

Ecological Monitoring Method and Tools for Dust Suppression During Coal Transportation and Storage

Ecological Monitoring Method and Tools for Dust Suppression During Coal Transportation and Storage

A new method of coal fine particles humidification and agglomeration: Synergistic dust suppression with composition of soap solution

Coking plants usually use surfactants to increase the surface wettability of fine coking coal particles, promote its agglomeration, and achieve the purpose of reducing dust emission. The Soap solution as a chemical agent contains not only soap base active ingredients, but also abundant surfactants and antifouling redeposition agents. The aim of this study is to optimize the dust suppression effect by blending the chemical composition proportion of existing soap solution, and analyze the interaction mechanism of each component on the surface of fine particles, then realize the dust suppression with low cost and high dust suppressor effect. Keeping the other ingredients remain the same, the hydrophilic organosilicone and carboxymethyl starch were selected as antifouling redeposition agents; the anionic surfactant sodium fatty acid methyl ester sulfonate (MES), non-ionic surfactant fatty acid methyl ester ethoxide (FMEE) and fatty alcohol polyoxyethylene ether (AEO-9) were used to mix in different proportions. The wetting effect and adsorption rate of the compound soap solution on the surface coal were tested. Then the particle coating efficiency, size growth rate and dust removal amount during the spraying of compound soap solution were tested and mechanism analysis in the device developed by the laboratory. The result indicates the wettability and agglomeration efficiency of coal particles can be obviously improved by increasing the proportion of FMEE and AEO-9. Compared with carboxymethyl starch, using hydrophilic organosilicon as antifouling redeposition agent can increase the adsorption capacity of raw coal to surfactants by 5% and the particle growth rate by 2%.

Optimization via response surface methodology of the synthesis of a dust suppressant and its performance characterization for use in open cut coal mines

To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmentally friendly soy protein isolate with methyl methacrylate. This dust suppressant could effectively control dust pollution in open cut coal mines. The optimized conditions for graft copolymerization in this case were determined by a response surface experiment designed with Design-Expert 10 software. Characterization by scanning electron microscopy showed a significant morphology change of the dust suppressant and the generation of a rigid and dense layer on its surface after interacting with coal dust. The layer exhibited good bonding and dust suppression performance. The analysis with Fourier-transform infrared spectroscopy revealed the appearance of new absorption peaks near 1300, 1072, and 1631 cm−1, demonstrating effective graft copolymerization. The proposed dust suppressant exhibited excellent wind erosion resistance, with a resistance that exceeded 90% at a wind speed of 6.5 m/sec. The successful graft copolymerization and effective bonding and curing of the dust suppressant on coal dust were experimentally verified. This is of great significance to the control of coal dust pollution.

Effect of TiO2-NPs on microbial-induced calcite carbonate precipitation

As a dust suppression method, microbial-induced calcium carbonate precipitation technology based on urease-producing bacteria has been widely used on roads; however, due to their low CaCO3 yield, microbial dust suppressants are not used in mining areas. To further improve the dust suppression effect of microbial dust suppressants, a TiO2-NPs/microbial dust suppressant was developed by adding TiO2-NPs to the microbial dust suppressant. The results showed TiO2-NPs improved the bacteria growth and the urease activity. The best formula of microbial dust suppressant was determined to be mineralized bacteria liquid (OD600 = 1.7) and TiO2-NPs 0.06 g/L. The wind erosion resistance tests showed that the dust suppression effect of the TiO2-NPs/microbial dust suppressant was better than that of the group without TiO2-NPs. The formation of CaCO3 was verified by Fourier-transform infrared spectrometry (FTIR), Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) and Transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDS). X-ray diffraction (XRD) results showed that the crystal forms of the produced CaCO3 were calcite and vaterite. These results indicated that TiO2-NPs improved the dust inhibition effect of microbial dust suppressants.

Improvement of Environmental Protection Technologies for Dust Suppression of the Surface of Tailing Dumps of Closed Tin Enterprises

Improvement of Environmental Protection Technologies for Dust Suppression of the Surface of Tailing Dumps of Closed Tin Enterprises

Researches on the numerical simulation of the dust pollution characteristics and the optimal dust suppression wind-speed on fully mechanised caving face

Dust removal by ventilation is a commonly used dust control strategy. This study analyses the characteristics of airflow transport and dust pollution on a fully mechanised top-coal caving face at different inlet wind velocities by using a numerical simulation experiment, and the best wind velocity for dust suppression is obtained. When the inlet wind velocity fluctuates in the range of 0.5 to 3.0 m/s, the overall dust mass concentration on the working face initially increases and then remains stable, but in the range of 2.5 to 3.0 m/s, the changes in the overall dust mass concentration and dust mass concentration of the respiratory zone on the working face are not significant. The dust pollution in the respiratory zone produced by the hydraulic support lowering pillar and moving frame on the working face is quantitatively analysed at different inlet wind velocities of 2.5 to 3.0 m/s to determine the optimum wind velocity for dust suppression on the working face. The optimum wind speed for dust suppression is 2.6 m/s. This study lays a foundation for the ventilation design and dust control in the early stage of a mine and for the establishment of a clean and green production mine.

Influence of coal properties on dust suppression effect of biological dust suppressant

In order to study the effect and influencing factors of biological dust suppressant on secondary dust of coal dust, the biological dust suppressant was prepared with bacillus pasteurii and 0.6 mol/L urea-CaCl2 solution. The experimental result shows that the yield of mineralized products of CC is the highest, reaching 81.11%, in bonding solutions with different calcium source and different concentration. For 5.0 g coal dust, 8 mL is the suitable spraying amount of bacteria solution and bonding solution. Biological dust suppressant has the best secondary dust suppression effect on coal dust with particle size above 200 μm. Moreover, it has the strongest effect on inhibiting secondary dust emission of lignite, and the weight loss rate of coal dust about 200 μm is only 0.84%. At the same time, the proportion of calcite crystals with the strongest thermal stability in mineralized products produced by MICP is higher. When the coalification degree of coal is lower, the effect of biological dust suppressant on secondary dust emission is better.

Study on dust diffusion characteristics of continuous dust sources and spray dust control technology in fully mechanized working face

When the roadheader works, it will produce a lot of dust, causing serious dust pollution to the roadway. In order to solve the problem of dust pollution in fully mechanized working face, the dust pollution law of roadway and the low surface tension spray dust removal technology of heading head were studied by fluid solid coupling simulation analysis software FLUENT. The results show that the optimum pressure of the spray head is 3.0 MPa, the droplet size of 50% is less than 3.00E-05 m, and the spray angle is 35 degrees. Reducing the surface tension of the solution can improve the atomization effect; When the surface tension drops to 61.9 mN/m, the spray size can be reduced obviously. Injection scheme D is the best injection scheme. Finally, according to the simulation results, the design of low surface tension spray dust suppression device for roadheader is carried out. The test and field application are carried out. The field application analysis shows that the dust reduction rate can reach 90%, and the dust reduction rate of respiratory dust can reach 85%.

Multi-scale study on the agglomerating and wetting behaviour of binary electrolyte-surfactant coal dust suppression based on multiple light scattering

This paper carried out a Multiscale study on the agglomerating and wetting behaviour of binary electrolyte-surfactant in coal dust suppression. The agglomerating behaviour is qualified by stability and SEM analysis, while the wetting behaviour is quantified by surface tension and sink time measurement. Results illustrates 11.78%-14.38% and 42.66%-74.40% improvement on surface tension and sink time reduction when compared with individual surfactants. The binary surfactant-electrolyte results in a stability index of 25.6 to 30.1 of treated coal particles and is 5.91 to 7.82 times higher than that of individual surfactant. Spearman’s correlation analysis confirmed that the solid–liquid two-phase TSI after the addition of electrolyte is more consistent with the dedusting rate than the sink time and the corresponding wettability. The wettability can only effectively determine the dust suppression effect of a specific binary surfactant-electrolyte solution on coal particles of different metamorphic degrees, but the stability index is more sufficient to evaluate the dust suppression performance of different binary surfactant-electrolyte solutions on coal particles of a certain degree of metamorphism.

Comparison of the coal dust suppression performance of surfactants using static test and dynamic test

Coal dust has a significant impact on miners' health, leading miners to have the most common occupational disease, Coal Workers' Pneumoconiosis. Water spray with surfactants is one of the most effective methods for dust control in underground mines. Different types of surfactants have different impacts on coal dust suppression efficiency. The evaluation of surfactants for coal dust suppression is important and can be categorized into two groups being the static tests and the dynamic tests. Previous studies have applied the static tests the most rather than the dynamic tests due to the complication of application. However, some studies showed that dynamic tests are more reliable to evaluate the surfactants’ performance. The aim of this study is to compare and analyze whether the results from static tests and dynamic tests are consistent for surfactants evaluation in terms of coal dust suppression. Different types and concentrations of surfactants were considered in experiments. It was found that the results from static tests were not consistent with dynamic tests. Moreover, although the surface tension was highly correlated with the sink time showing in some surfactants, it was not applicable for all surfactants. Most importantly, due to many factors such as airflow and foam generation that were taken consideration in dynamic tests, it could be more reliable and accurate considering the discrepancies existing between static and dynamic tests. The results of this study could be applied to determine the evaluation methods of surfactants for coal dust suppression.

Formulation Development and Performance Characterization of Ecological Dust Suppressant for Road Surfaces in Cities

In order to solve the problem of road dust pollution, an ecological dust suppressant for road surfaces has been developed using monomer, orthogonal, and optimization experiments and based on the dust raising mechanism. A humectant, hygroscopic agent, coagulant and surfactant and their concentration ranges have been determined through monomer experiment. The preliminary formula of the dust suppressant has been obtained through orthogonal experiment, with the water loss rate, moisture content rate, viscosity value, and surface tension value serving as experimental indexes. The optimal formula for the dust suppressor has been calculated through an optimization experiment, with the toxicity, moisture absorption and retention performance of plants, and the relative damage rate of plant seeds serving as experimental indexes. Based on the performance characterization of ecological road dust suppressant, the ecologically and environmentally friendly dust suppressant demonstrates fine moisture absorption and retention performance, good wind and rain erosion resistance, and no toxicity. The ecological road dust suppressant developed herein covers extensive raw material sources. It is ecologically and environmentally friendly, fit for most urban roads, and has a fine dust suppression effect. Meanwhile, it also can bring in good economic and social benefits, demonstrating its broad application prospects.