Dust Reduction Research Articles

Effects of Titanate on Brake Wear Particle Emission Using a Brake Material Friction Test Dynamometer

We investigated the effect of lepidocrocite-type layered titanate, which is compounded in brake pads, to reduce brake particle emissions. The dust reduction effect of titanate was evaluated using a small-scale inertial brake material friction test dynamometer. The results suggested that brake particle emissions are related to the microphysical structure of the pad surface, such as the uniformity of the friction film and secondary plateau formation, and that friction materials containing titanate contribute significantly to reducing both particle mass (PM) and particle number (PN) emissions of brake particles in both non-asbestos organic (NAO) and low-steel (LS) pads. In particular, LS pads generally have a problem of having more brake particles than NAO pads, but this study found that brake particles can be significantly reduced by compounding titanate instead of tin sulfide.

Development of New Spray Dust Suppression Materials in Metal Mines and Prediction of Algorithm Simulation Effect

PROBLEM: Dust contamination in metal mining poses substantial dangers to environmental quality and human health. Modern mining operations cannot use traditional spray dust suppression methods because they are poorly adapted to changing climate conditions, low efficient, and detrimental to the environment. INTRODUCTION: Dust pollution seriously impacts the environment and human health in metal mine operations. Traditional spray dust suppression technology has many problems, such as limited effect, environmental impact, and poor climate adaptability. OBJECTIVES: The purpose of this article is to develop a new type of spray dust suppression material and predict its dust suppression effect through algorithm simulation. Firstly, efficient and environmentally friendly dust-reducing materials were screened, and after evaluating the dust-reducing effect under laboratory conditions, the optimal material combination was determined. METHODS: Using computational fluid dynamics (CFD), a numerical model of the spray process was constructed to simulate the dust suppression effect of different materials under different climatic conditions. RESULTS: The results show that the highest dust reduction efficiency of the new spray dust reduction material is more than 4.3% higher than that of the traditional material, and it shows good stability. CONCLUSION: The new spray dust control material and its effect prediction method studied in this article provide an effective solution for dust control in metal mines, which has important theoretical value and practical application prospects.

Numerical simulation for spray spatial distribution of swirl nozzle and its target dustfall area prediction.

The droplet breakup and distribution of the internal flow field and external spray field of a nozzle were obtained under different pressures. The thickness of the liquid film increased with pressure as a quadratic function. The maximum value of 0.281mm at 2MPa decreased to 0.172mm at 10MPa, equivalent to 38.8% decrease. The MATLAB was used to obtain the particle size distribution characteristics of the droplets under different pressures. At 2MPa, droplet breakup dominated the axial interval [0-700mm]. With the increase of pressure, D50 distribution as a whole continues to decrease, 2-6MPa change, the particle size reduction is larger, every increase of 2MPa reduced by about 15%. 6-10MPa change, the particle size reduction is smaller, every increase of 2MPa reduced by about 8%. A model to predict the optimal dust reduction areas under varying pressures was developed. The prediction results indicate that at pressures of 5MPa and 9MPa, the target dust removal areas were [344mm, 710mm] and [424mm, 942mm] along the axial direction, respectively.

Recent Patents on Particle Wettability Measurement and Improvement

Background: As the coal mining industry becomes more mechanized, it leads to a large number of coal dust particles suspended in the air, polluting the surrounding environment, accompanied by an increase in fine-grained low-rank coal particles and a low recovery rate of a large amount of organic matter in the particles, wasting resources. Objective: The study of particle wettability can have an impact on spray dust reduction and particle flotation efficiency. By adjusting the hydrophilicity of coal powder particles, the generation of suspended coal dust can be effectively suppressed. By adding surfactants, the flotation separation efficiency of coal particles can be improved. Method: This article introduces the measurement method of particle wetting properties and methods to improve the wetting properties of particles, providing a reference for studying the wetting properties of particles Results: The measurement of particle wetting properties is more accurate, simple, and convenient. Improving the wetting properties of particles by adding additives has significant implications for later dust reduction and particle flotation. Conclusion: This thesis provides an important basis for studying the wettability of particles, modifying the wettability and hydrophilicity of particles, providing specific guidance for improving the wettability of particles for spray dust reduction and particle flotation, and greatly improving industrial production efficiency.

Study on the thermal hazards of anionic surfactant AES on lignite via experiments and calculations

Spray dust reduction is a commonly used dust reduction method in coal mines and has been widely adopted. However, the thermal stability of coal dust after being wetted by dust suppressants remains unknown. The work aimed to investigate the potential environmental hazards posed by the secondary dust dispersion resulting from the cracking of lump coal dust after being wetted by surfactants and subsequently air-dried. Lignite and AES were used as experimental samples. Use thermodynamic equations to analyze, calculate, and compare the changes in the average apparent activation energy of lignite before and after AES solution wetting. Compared with lignite before AES solution wetting, the combustion characteristic index of lignite decreased by 1.93 % after wetting, and before and after AES solution wetting, the average apparent activation energy of lignite calculated by reaction kinetics methods decreased by 7.6 %, 6.7 %, and 17.1 % respectively. FTIR analysis shows the proportion of aliphatic hydrocarbons in lignite after AES solution wetting has decreased compared with before wetting, and the proportion of oxygen-containing functional groups has shown an upward trend. The work elucidated the complex microscopic mechanisms underlying hazards caused by secondary dust dispersion, providing new scientific evidence for preventing and controlling coal dust explosion accidents.

Verification of On-Site Applicability of Rainwater Road Surface Spraying for Promoting Rainwater Utilization and Analyzing the Fine Dust Reduction Effect

This study conducted a pilot test and field demonstration to analyze the feasibility of using rainwater for road surface sprinkling and its effectiveness in reducing fine dust to create sustainable cities. The pilot test results verified the effectiveness of rainwater sprinkling on road surfaces in reducing fine dust. Subsequently, to ensure field applicability, a test bed with different pavement sections was established along Ojeong-ro in Bucheon, Gyeonggi-do, and a circulatory system for reusing the runoff rainwater was installed and tested for its acceptable dust reduction effectiveness. The results showed that the section with porous pavement exhibited a significant reduction in acceptable dust levels, and a trend of decreasing pollutant levels due to the initial washing effect of rainwater was observed. However, the water quality and quantity analysis revealed that additional purification processes are necessary to reuse the water for road surface sprinkling. Based on these findings, this study suggests that expanding porous pavement and introducing purification systems are essential for installing rainwater utilization facilities to reduce fine dust in urban areas. This research provides critical foundational data that can contribute to urban environmental improvement and establish a sustainable water circulation system.

Study on the development and dust suppression performance of a novel composite dust suppressant for metal mines

The significant amount of dust generated during the metal mining process affects both personnel health and the environment. Some mines, such as magnetite mines, produce magnetic dust that is easily adsorbed onto equipment, causing equipment failure and other issues. To solve such problems, a composite dust suppressant was synthesized in this study using carboxymethyl cellulose sodium (CMC-Na), primary alcohol ethoxylate (AEO), and polyethylene glycol (PEG) as raw materials. Firstly, the optimal ratio was determined according to the response surface method. Subsequently, the performance and dust reduction efficiency of the suppressant was evaluated. According to the optimal formulation ratio, the dust suppressant exhibited a viscosity of 34.5 mPa·s and a surface tension of 28.46 mN/m. The wind erosion resistance, compressive strength, and water retention of the dust samples were improved following the dust suppressant application. The loss rates were only 0.025% and 0.9% at wind speeds of 3.5 m/s and 20 m/s, respectively. Simulation experiments indicated that the suppressant achieved a dust suppression efficiency of 82.7% for respirable dust and 90.91% for total dust. These results demonstrate that the suppressant possesses high dust removal efficiency and effective dust suppression, aligning with the application requirements of metal mines and contributing to the mitigation of dust issues during mining operations.

Оценка влияния вредных факторов производственной среды в литейном цехе

Harmful factors in the working area of foundry operators are considered. The complexity of workflows affects the quality of air in the foundry. The casting process is accompanied by the generation of a significant amount of dust as well as high levels of noise and vibration. The relevant aspect of the study is the assessment of the state of occupational safety, considering the harmful factors at the production in question. Dust content has been thoroughly investigated by dispersive and elemental analysis of dust using X-ray fluorescence analysis and laser diffraction. The impact of the vibroacoustic factor has been studied. An analysis of the sound pressure level in the working areas of the foundry has been provided. The authors have proposed technical measures to reduce dust content and the level of impact of the vibroacoustic factor. The development of a system of measures to minimize harmful impact has been based on a combined analysis of factors. Methods to reduce noise and dust content at workplaces are proposed as follows: organizing a highly efficient system of post-treatment of dust emissions, increasing equipment sound absorption, installing structures to reduce noise pollution, and using a coating system made of dense rubber structures (compounds). Ensuring safe working conditions in working areas of the foundry has been studied; the improvement of working conditions due to the improvement of existing and installation of new noise and vibration protection means has been proposed. An integrated approach to the assessment of production factors has been provided, which has been the key element for the development of engineering and organizational protection measures. The integrated analysis helped identify the degree of impact of harmful factors such as noise, and dust content on machine operators during the casting process and to conduct a comparative assessment of sound pressure levels. The sound pressure can be reduced by 8–10 dB using improved mechanisms of shot-blasting chamber operator protection. More extensive dust protection measures are proposed due to the sample content of 85% of the dust mass less than 100 microns and multicomponent dust with a high content of silicon and iron. The findings provide a technical value for the substantiation of the modernization of noise and dust reduction systems at foundry operator workplaces.

Reduction of the Low Zinc-containing EAF Dust and Coke

T his paper presents the result of reducing the pellets prepared from low zinc (Zn) containing electric arc furnace dust (EAFD) and coke. The temperature is predetermined in the 1000 to 1200 °C range, and the holding time varies from 30 to 90 minutes. The Zn and iron (Fe) content in the EAFD is analyzed by the ICP-OES method as 15.85 and 20.50 wt.%, respectively. Franklinite (ZnFe2O4) and zincite (ZnO) are the majority compounds of Zn. The experimental result shows that the reduced Zn vapors from the heated pellets increased the Zn removal with increasing temperature and time. The Zn removal from the pellets is significant at temperatures of 1100 and 1200 °C, at which the efficiencies reached about 95 % for the holding time of 90 minutes. The fact that the Fe content was around 31 wt.% and metallic Fe was thought to be present in the pellets heated at 1200 °C would be beneficial if further residue recycling could be done.

Theoretical study on nonlinear seepage mechanism in fractal dendritic fracture network of low permeability coal with water injection

Coal seam water injection technology is adopted by many mines as an effective means of dust reduction in coal mines. There is a threshold pressure gradient phenomenon in the process of water injection in low permeability coal seam, which makes the flow of pressure water in the fracture structure of coal body present nonlinear seepage characteristics. To reveal the theoretical relationship between the structural parameters of coal and the nonlinear seepage characteristics, firstly, the Bingham fluid constitutive equation is used to describe the non-Newtonian behavior in low-permeability coal. Combined with the fractal tree-like bifurcation fracture network model, a mathematical analytical model of threshold pressure gradient is established. Secondly, the model was verified by high-pressure water invasion and radial seepage experiments, and the sensitivity of the model was analyzed. The results show that the error between the theoretical calculation value and the experimental measurement value is between 8.65 % and 42.4 %, which verifies the validity of the model. The above research results can provide a theoretical basis for improving the water injection effect of low permeability coal seam.

A Lake at the Mt. Fuji (Lake Motosu) Recording Prolonged Negative Arctic Oscillation as Reduction of Aeolian Dust Due To Westerly Pathways During the Holocene

AbstractEast Asia is a major source of dust accounting for 20% of the global dust emission. Work on reconstructing past changes in dust transport in East Asia is complicated by difficulties in distinguishing local sedimentation from aerial material and lack of suitable material for age determination. Here, we address these issues and present a new dust proxy record from Lake Motosu, located on the Pacific side of Japan. The record is anchored by a high‐quality tephra and radiocarbon chronology. Because Lake Motosu is situated in a quartz‐free basaltic volcanic province, all quartz deposited in the lake is likely to be aerially sourced, and variations in quartz content should reflect past changes in dust transport. Our new record detects a low dust deposition event from 3.0 to 2.0 ka. This event corresponds to elevated sea surface temperature in the Sea of Japan and climate conditions similar to a negative phase of the Arctic Oscillation, indicating an association with the weakened Westerlies and with less frequent dust storms in the source region. The increase in spatial resolution of past dust transport reconstructions will further improve our understanding of the mechanism related to dust emission from East Asia.

The effects of green finance on pollution and carbon reduction: Evidence from China’s industrial firms

Reducing pollution and carbon emissions is important but requires a large amount of capital. Green finance is becoming an important market-based instrument. Few literatures have focused on the direct impact of green finance on corporate environmental performance. This study investigates the effects of green finance on air pollution and carbon reduction in China’s industrial firms from 2008 to 2015. Results show that green finance promotes CO2 and air pollution reduction. Moreover, green finance has a synergistic effect on SO2 and carbon reduction, but not on reduction of dust and carbon emissions. Our findings suggest that green finance reduces emissions by improving corporate energy utilization efficiency. Furthermore, we find that the effects of green finance on emission reduction are more significant among non-state and non-listed firms. These findings have important implications for the development of green finance and synergistic reduction of air pollutants and carbon.

Experimental Investigation on Bituminite Dust Suppression Characteristics of a Bonding-Wetting Composite Dust Suppressant.

In order to reduce the occupational health hazard of coal dust to miners, surface tension and viscosity tests and bituminous coal powder sedimentation experiments were conducted. A composite dust suppressant with bonding-wetting effects was developed. Meanwhile, based on the FTIR test and peak-differentiating curve fitting, the changes of peak areas of coal samples before and after dust suppressant treatment were investigated, with quantitative analysis on hydrophilic and hydrophobic groups. Gravity drop weight tests and Malvern particle size analyses were carried out. The particle size distribution was studied based on the Boltzmann function model. The characteristic particle size theory was adopted to analyze dust reduction performance and time's effect on the performance. Results show that the surface tension of the composite dust suppressant is 31.02 ± 0.09 mN/m with the viscosity being 84.60 mPa·s for the mixture of 0.1% SDS solution and 0.4% CMC-Na solution being 1:5. The ratio of the hydrophilic group of bituminous coal reaches 97.37% affected by the dust suppressant with a good wetting and cohesiveness effect. The characteristic particle size D 10 of dust increases by 11.77 and 46.67%, D 50 rises by 7.56 and 36.89%, and D 90 grows by 10.56 and 32.96%, respectively. The compressive strengths of the Shenmu coal sample and Lucun coal sample increase by 82.86 and 66.72% compared with that of raw coal after 48 h of dust suppressant treatment. The breakage degree at the end face of treated coal is smaller than that of raw coal. The composite dust suppressant makes the particles in coal more cohesive and effectively weakens the dust-producing property. Research results are of practical significance for improving the effect of water injection on dust reduction.

Experimental Study on Collaborative Electric Furnace Dust Reduction with Multi-solid Waste in Steel Plants: Turning Waste into Treasure, Saving Energy and Reducing Emissions

Experimental Study on Collaborative Electric Furnace Dust Reduction with Multi-solid Waste in Steel Plants: Turning Waste into Treasure, Saving Energy and Reducing Emissions

Research on prepositioned air distribution and dust control devices for continuous mining faces

This study, based on the construction of a wind flow-dust two-phase coupled diffusion model, develops a novel method using a prepositioned air distributor to create an air curtain for dust control. This research involved the analysis of wind flow transportation patterns and dust diffusion mechanisms with varying structural parameters, and the verification of simulation results through field tests. The findings indicate that with the increase of the axial horizontal opening angle of the prepositioned air distributor, the wind speed of the air curtain decreases, while the size of the vortex field in the heading face area expands. Increasing the axial vertical opening angle enhances the strength of the vortex, leading to improved dust control abilities. The dust concentration at the rear of the tunnel initially decreases and then rises. Additionally, as the turning angle increases, the speed at which the wind flow diffuses towards the rear of the tunnel also rises. Compared with traditional ventilation methods, the dust reduction efficiency at the respiratory zone height is improved to over 94.0 %. The concentration of dust within the tunnel is significantly reduced, with approximately 98.9 % of the dust confined within a 10.0 m range from the heading face.

Transitioning to Microplastic-Free Seed Coatings: Challenges and Solutions.

This review addresses the issue of replacing manufactured microplastics in seed coatings used in agriculture. Firstly, it focuses on the policy and regulatory actions taken on microplastics at a global level. There is no consensus within the scientific community on the definition of a microplastic and, more generally, on the classification of plastic debris. Nevertheless, several decision schemes have been proposed in an attempt to define the notion of microplastics. The different criteria relevant to this definition, such as the size, physical state, chemical structure, origin, and persistence of microplastics, are discussed, with a comparison being made between the REACH regulation and the scientific literature. Seed production and processing are also discussed, with the functions of seed coatings being explained in order to gain a better understanding of the properties to be considered in a substitution strategy for currently used microplastics. The main challenges are multiple; substitutes must provide the same performance as microplastics: (i) improving the adherence of the treatment to the seed, (ii) distributing the treatment more evenly over the seed, (iii) reducing the amount of dust-off when handling treated seed, and (iv) improving the seed flowability, which is particularly important during the sowing stage, all while preserving the physiological properties of the seed. Substitute polymers are proposed according to the desired performance and functional properties: two main chemical families of biopolymers were identified in the literature: polysaccharides and proteins. Among them, 13 and 6 polymers, respectively, complied with REACH regulation, demonstrating adhesion, dust reduction performances, and preservation of seed physiological quality in particular. This work aims to guide future studies on microplastic substitution in seed coatings, and to highlight research needs in this area. It is based on an analysis and discussion of the literature, identifying and listing potential substitutes.

Social impacts arising from road infrastructure projects in Sub-Saharan Africa: better management of social issues is needed in road construction, upgrading and rehabilitation

ABSTRACT Despite the use of environmental and social impact assessments for road projects, severe social impacts continue to occur. We discuss the social impacts associated with the construction, upgrading, widening and/or rehabilitation of roads in Sub-Saharan Africa. In addition to a literature review, we analysed 10 road projects in Uganda by examining project planning documents, and undertaking in-depth interviews, group interviews and field visits. While there were some benefits from these road projects, especially dust reduction where roads became sealed, the significant land acquisition necessary for these linear projects has led to physical displacement, economic displacement, and disruption to the livelihoods of local people. Other issues included: inadequate community engagement; delayed payment of compensation and inadequate compensation; gender-based violence; poor road construction practice causing community safety concerns; project-induced in-migration or influx; sexual harassment; impacts on children; and issues around sex work. The lack of local community acceptance (social licence to operate) of the projects resulted in construction delays and increased costs. For more acceptable road projects, better community engagement, improved planning and management, and adequate funding for resettlement and compensation are essential.

Study on dynamic characteristics of anionic surfactants containing ethoxy groups wetting bituminous coal

Coal dust restricts coal mine safety and green production. Wet dust removal is widely used in coal mining, processing and transportation. High-efficiency dust suppressants help control coal dust and improve the working environment. The wetting behaviors of dust suppression droplets on coal affect the dust reduction efficiency. In order to select high-quality and efficient water-based materials, four ethoxy-containing surfactants with similar structures, fatty alcohol ether sulfate (AES), lauryl alcohol sulfosuccinate disodium (MES), fatty acid methyl ester ethoxylates (FMEE) and fatty acid methyl esters ethoxylate sodium sulfonate (FMES), are selected to prepare solutions with different concentrations. Through the droplet impact wetting experimental system, the dimensionless spreading coefficient of droplets is compared. The results show that the spreading behavior of the four surfactant-containing droplets is better than that of distilled water droplets, and the maximum dimensionless spreading coefficient follows the rule of AES > MES > FMES > FMEE >distilled water. The maximum dimensionless spreading coefficient of the droplet first increases sharply with the increase of the concentration, and then increases slowly when the concentration reaches the critical micelle concentration (CMC). The adsorption configuration of water-surfactant-coal system is simulated by molecular dynamics (MD) simulation. The relative concentration distribution of each component and the mean square displacement (MSD) of water molecules are analyzed. The interaction energy of the system is calculated. The simulation results verified the effectiveness of the impact wetting experiment results.

Research on microscopic wetting mechanism of talcum powder by compounded surfactant for spraying dust reduction

Adding surfactant is an effective method to improve the dust removal efficiency of talcum powder dust. Based on the optimization of surfactants, this paper proposed an efficient compound surfactant scheme by calculating interaction parameters, adsorption simulation, and wettability test experiments. Molecular dynamics simulation was used to analyze the interaction mechanism between compound surfactant and talcum powder. Tests of spraying talcum powder with compound surfactants under different pressures were carried out. The results show that the combination of anionic surfactants SDS and SDBS with nonionic surfactants Tween 80 and AEO9 has a positive synergistic effect. The better the wetting effect of the compound system, the more ordered the surfactant molecules are arranged. Meanwhile, the diffusion ability of water molecules is stronger, and the thickness of the solid-liquid interface is larger. The wetting effect of compound surfactant on talcum powder is mainly influenced by van der Waals force. The dust removal efficiency test shows that SDS-Tween 80 compound surfactant with a pressure of 1.5 MPa and molar ratio of 0.4:0.6 is the best spray dust removal scheme. The research results are helpful to guide the application of compound surfactants in talcum powder dust control.

Study on the Influence of Some Ventilation Parameters on Dust Dispersion in Heading Face Coal Mine Using CFD Numerical Model

Coal dust is one of the environmental factors that seriously affect the health of workers as well as the mining equipment in underground coal mines. At present, coal dust is commonly generated during drilling, blasting, excavation, and transportation processes in mining operations. During mining blasting processes, coal dust is generated with varying particle sizes and high concentration levels. High concentrations of dust will affect mining operations and increase the ventilation time required for mining faces. In addition, coal dust exists in suspended form in the roadway and is harmful to human health, especially fine dust particles that have a negative impact on work efficiency. To improve ventilation efficiency and eliminate coal dust, this article presents a CFD-DPM numerical modeling method that integrates a DEM collision model based on the finite element method to analyze the motion characteristics of airflow and dust particles in the mine tunnel, while considering collisions between particles and between particles and walls. The article analyzes the distribution of wind speed, the dispersion of dust in the space around the roadway, and dust concentrations at distances of 1 m, 3 m, and 6 m from the working personnel and at a position 1.5 m above the roadway floor, corresponding to the breathing zone of the workers, with varying parameters such as velocity and duct position. The results indicate that with a wind velocity of V = 18 m/s and an air duct height h = 3.0 m, the best dust reduction results are achieved, and they provide theoretical guidance for selecting and optimizing ventilation parameters in dust control.