Discussion on Dust Removal(Suppression)System of Crushing Station in Open-Pit Coal Mine

This paper introduces the method of coal dust treatment in crushing station and the present situation of dust removal system in typical open-pit coal mine crushing station in China,and expounds the research idea of determining comprehensive dust removal(suppression)system in crushing station inspired by the working principle of"range hood".Based on the design example and link optimization of the crush-ing station of open-pit coal mine I of Thar coalfield,this paper finally draws some conclusions on the key technologies of dust removal(suppression)system of open-pit coal mine crushing station.This study has certain reference value for the technical innovation of dust removal(suppression)system in crushing station,the realization of green mining in"crushing link",and the reduction and avoidance of ecological environment pollution in mining area.

Research Progress and Prospect of Road Dust Suppressants

Road dust has great adverse effects on traffic quality,traffic safety,atmospheric environment quality,and human health.Therefore,with the continuous development of modern science and technology,the research of road dust suppressants is also progressing.To promote the rational application and development of road dust suppressants,the research progress and prospects of them are analyzed in this paper.It includes a basic overview of road dust suppressants,the main types,the usage and precautions,and the main development direction.It is hoped that this analysis can provide some reference for further research and development of road dust suppressants.

Online coal dust suppression system for opencast coal mines

Coal is the major source of power in India and world over.Coal mining is an essential industry which has a major role in the economic development of the country.Most major mining activities contribute directly or indirectly to air pollution.Coal dust is a major air pollutant which affects the personal working in the mines and also people residing in villages near the mines.Air pollution due to coal particulates can affect human health and cause damages to the environment.Hence effective pollution control mechanisms are needed to keep the pollution levels within permissible levels.The easiest and most common method employed for dust suppression worldwide is sprinkling of water.In majority of mines,water sprinklers are operated manually and can lead to wastage of water due to over sprinkling.It can also prove to be ineffective in dust suppression if sprinkling is not done properly.The paper proposes a system which can be deployed to automate the dust suppressions sprinklers.The system will monitor the concentration of PM_(10) and PM_(2.5) in the air and initiate sprinkling operation when the particulate matter content exceeds preconfigured limits.

New Respirable Dust Suppression Systems for Coal Mines

Dust suppression in coal mines is a worldwide problem which has not been solved effectively. The applica-tion of negative pressure secondary dust removal (NPSDR) is a breakthrough in the coal mine safety field. In this paper,NPSDR technology and ultrasonic dust suppression systems are introduced. High pressure water is supplied to the NPSDR device which is mounted on the shearer. A negative pressure field is formed in the device. At the same time,the dusty air around the shearer drum will be sucked into,and purged from,the NPSDR device by the negative pressure field. An ultrasonic dust suppression system uses water and compressed air to produce micron sized droplets which suppress respirable coal dust effectively. The NPSDR technology can be used for shearer dust suppression while ultra-sonic dust suppression can be applied in areas such as the transportation positions. These dust suppression methods have the following advantages: high efficiency,wide applicability,simple structure,high reliability and low cost.

Dust Suppression with Glycerin from Biodiesel Production: A Review

An increasing number of countries and areas in the world suffer from either natural or anthropogenic dust, which results in a serious hazard with respect to the environment and to personal health and safety. This paper reviews and summa- rizes open literature involving the use of glycerin in dust control applications. Glycerin, a by-product from biodiesel manufacturing, has been evaluated for dust suppressant performance when applied alone as aqueous solutions, or in combinations with surfactants, polymers, or other chemicals. There are reports indicating that glycerin is effective in some dust suppression applications, although details about its use and performance metrics are generally lacking. Re- cent growth of the biodiesel industry has significantly increased the supply of crude glycerin, making it an economically attractive material for use in dust suppression. This paper also highlights several environmental accidents caused by irresponsible discharges of crude glycerin, and points out the need to understand environmental consequences of gly- cerin and its impurities when used in dust suppression applications.

A new design of foaming agent mixing device for a pneumatic foaming system used for mine dust suppression

To overcome the drawbacks of the conventional foam technology used for dust suppression,including large pressure loss,high water pressure and low driving pressure,a new pneumatic foaming system is introduced.Then an original design of foaming agent mixing device is proposed,and its performance is investigated and evaluated under different pressure compensations.Experimental results show that the maximum absorption amount increases by 2.9-6.7 times at a pressure compensation of 0.04-0.2 MPa compared with no pressure compensation.The pressure loss and pressure fluctuation both reduce significantly with increasing pressure compensation.The critical outlet pressure increases by30.4-240%.Field application indicates that the proposed mixing device ensures the reliable addition of foaming agent used for foam dust suppression.The effect of foam on dust suppression is remarkable,and the economic cost of foam is low.Therefore,there is reason to believe that the new mixing device will greatly promote foam technology to be widely used for suppressing dust in underground coal mines.

A new adding method of foaming agent used for foam dust suppression in underground coal mines

To realize a stable addition of foaming agent used for foam technology, a new adding method using the jet cavitation was introduced, and its performance was investigated experimentally under different operating conditions. Experimental results show that the bubble region in the jet device has a constant vapor pressure, which creates a good condition for liquid absorption, while it shrinks with increasing outlet pressure. The liquid absorption amount keeps unchanged when the outlet pressure is lower than a critical value. The critical outlet pressure increases by 40% with decreasing cavitation absorption amount, which is especially suitable for mini-flow quantitative addition of foaming agent used for foam dust suppression. Its effectiveness on suppressing mine dust was evaluated in a heading face of underground coal mines. Field application indicates that the reliable and simple foaming system adopting the new adding method makes a marked dust suppression effect. The working environment of heading face is significantly improved, ensuring the safe tunneling and personal security.

Suppression of a spontaneous dust density wave by modulation of ion streaming

Synchronization of a self-excited dust density wave has been experimentally investigated in a strongly coupled dusty plasma.A dust density wave of frequency^78 Hz is spontaneously generated from the dust void boundary due to the ion streaming instability.The electric field in the dust void region is measured,and the electric field force and ion drag force on the dust particles at the void boundary are estimated to explain the mechanism of spontaneous dust density wave excitation.Synchronization occurring through the suppression mechanism is observed by modulating the ion streaming by applying an external sinusoidal signal to the dust void.At sufficiently high modulation amplitude,the onset of period-doubling bifurcation is observed.Fast Fourier transform spectral analysis is done using time-series data obtained from high-speed video imaging.The van der Pol equation with a force term is used to correlate the observed suppression phenomena.

Dust Suppression on Open Pit Drill Rigs--Case Study from Skorpion Zinc Mine

Spotters and samplers around the drill rigs can be exposed to high dust concentrations. In this study it was found that individuals were exposed to as much as 14.2 mg/m3, which exceeds the OEL （Occupational Exposure Level） of 10 mg/m3 [1]. The work on which this paper is based included an extensive literature study, as well as field investigations. Number of additional dust suppression interventions was identified. These improvements, listed below, will assist in reducing dust concentrations arotmd the drill rigs： Increase maintenance frequency on the shroud, sealing ring, suction pipes and filters of the drill rigs. Design and install new overlapping rubber belts on the shroud of the DM45. Install an air-blocking shelf on the inside perimeter of the shroud of the DM45. Install an airflow meter to ensure that the Qc：QB ratio never drops below 3：1. Only allow wet drilling. Flush the dust collector system more regularly with compressed air to ensure that it does not become blocked. Introduce stricter supervision to ensure that the suction pipes are always connected to the shroud. Give drill rig operators more advanced training to ensure more effective drilling in order to reduce dust levels.

Development and characterization of formulation of dust-suppressant used for stope road in open-pit mines

The components of dust-suppressant were determined based on the analysis on characteristics and mechanisms of road dust raising in open-pit mines. The components were initially selected from moisture agent, coagulation agent and surfactant. The optimal formulation was determined based on orthogonal test and using the water loss rate as the evaluation index. The performances of moisture releasing and adsorption, wind resistance of optimal formulation in the natural environment were tested. The results show that the formula obtained in experiments provide a good performance of moisture absorption and water retention, and it also had a good dust preventing and controlling performance due to its high surface strength and consolidation under dry conditions. It has good application prospects considering the wide variety of sources for materials and the simple preparation process.

Water-retaining properties of NCZ composite dust suppressant and its wetting ability to hydrophobic coal dust

Coal dust is a primary threat to underground coal miners.The most common approach to control coal dust is hydraulic methods,such as water spray and coal seam water injection.To improve the dust suppressant efficiency of hydraulic methods,a novel chemical composite dust suppressant,called NCZ,was prepared in this study using calcium chloride(CaCl_(2)),magnesium chloride(MgCl_(2)),and nonionic surfactants using a thermal synthesis method.The water-retaining properties of NCZ powder and its solutions were characterized using the water absorption rate(WAR)and evaporation rate(ER),respectively,and the wetting abilities of the NCZ solutions on coal dust were tested using the initial contact angle(ICA)and sink rate(SR).The results indicate that the NCZ solutions have anti-evaporation effects,and the ER of the solution with a 20.0 wt%NCZ is reduced by 11.7%compared with that of clean water.Furthermore,NCZ solutions have remarkable enhancement effects on the wettability of coal dust.The ICA and SR of clean water and the NCZ solution at 20.0 wt%are 141.9°and 0 mg/s,and 29.3°and 1.46 mg/s,respectively.Finally,quantitative relationships between the solution surface tension and the ICA and IR were established using the least squares method.This study provides a new product for dust suppression in underground mines,which is significant for the optimum applied con-centration of dust suppressant in mining operations.

Retrofitting Sprinkler Systems for Suppressing Dust Generated by Moving Vehicles Inside Farms

Fugitive dust is one of the well known problems in agriculture and it affects both humans and machine producing quality. Dust problems can seriously cause harmful diseases to workers and ruin expensive equipments. In this study, a dust formation generated in open environment by vehicles was analyzed on unpaved roads. Formed dust was measured by calculating total forces on the PM10 （airborne particles smaller than 10 mm） of dust particles, such as air velocity, gravity forces and air turbulence generated by the moving vehicle. The water fogger nozzle discharge was measured to determine the approximate droplets quantity in the air. The foggers were used to suppress the generated dust in an open environment via installing a proposed automatic suppression system which opens automatically when vehicles pass under the system. The relationship between water droplet speed and ability of collecting fugitive dust showed that high air temperature above 40oC and wind speed above 10 m s-1 have negative effects on the system’s ability of collecting dust due to evaporation of small radius droplets and/or drifting water droplets away from the effective area. The overall system efficiency was found to be 85% and the proposed dust suppression system was found to be a satisfying solution for reducing fugitive dust hazards.

Preparation and performance analysis of a coking coal dust suppressant spray

Coking coal dust is extremely hydrophobic;therefore,combination with droplets in the air is difficult and dust suppression is challenging.Here,a dust suppressant spray for coking coal dust was studied in order to improve of the combination of droplets and coking coal dust.Based on monomer optimization and compounding analysis,two surfactant monomers,fatty alcohol ether sodium sulfate(AES)and sodium dodecyl benzene sulfonate(SDBS)were selected as the surfactant components of the dust suppressant.The surfactant monomers were combined with four inorganic salts and the reverse osmosis moisture absorption of each solution was determined.By combining the reverse osmosis moisture absorption values with the water retention experimental results,CaCl_(2)was identified as the optimal inorganic salt additive for the dust suppressant.Finally,the optimal concentration of each component was obtained using orthogonal experimental design i.e.,AES(0.03%),SDBS(0.05%),and CaCl_(2)(0.4%).The dust suppressant solution formulated using this method had a high moisture absorption capacity and excellent performance.

Mechanism of micro-wetting of highly hydrophobic coal dust in underground mining and new wetting agent development

The internal mechanism of the high hydrophobicity of the coal samples from the Pingdingshan mining area was studied through industrial,element,and surface functional group analysis.Laboratory testing and molecular dynamics simulations were employed to study the impact of three types of surfactants on the surface adsorption properties and wettability of highly hydrophobic bituminous coal.The results show that the surface of highly hydrophobic bituminous coal is compact,rich in inorganic minerals,and poorly wettable and that coal molecules are dominated by hydrophobic functional groups of aromatic rings and aliphatic structures.The wetting performance of surfactants as the intermediate carrier to connect coal and water molecules is largely determined by the interaction force between surfactants and coal(Fs-c)and the interaction force between surfactants and water(Fs-w),which effectively improve the wettability of modified coal dust via modifying its surface electrical properties and surface energy.A new type of wetting agent with a dust removal rate of 89%has been developed through discovery of a compound wetting agent solution with optimal wetting and settling performance.This paper provides theoretical and technical support for removing highly hydrophobic bituminous coal dust in underground mining.

Transmission and Suppression of Avian Influenza Virus

The growth of AIV is possible with supply of minerals from aeolian desert dust, as cofactors of enzymes, and thus the blockage of the aeolian desert dusts to the poultry farmhouse is important to suppress the enzymatic activity of AIV. South Georgia of Subantarctic Islands may be the source of Continental AIV, so that Continental AIV can become endemic within the local bird population when surrounding environments are close to Subantarctica of South Georgia. There are food webs in sequence of aquatic virus, bacteria, phytoplankton, zooplankton, krill, fish and squid while penguins feed on the fish or squid infected by mutant virus to generate LPAI after an incubation period. When migratory birds move to the Continents, HPAI can spread in the Continents due to low UV-B radiation, enough feed of rice, wheat, corn, wetland, and mineral-enriched desert dust. The clean room is equipped with air washers to remove aeolian dusts and migratory birds feces from working personnel and equipments, heaters to keep the pasteurisation of ultra-high temperature at 135°C for 1 - 2 seconds to inactivate AIV, humidifier to keep wet state above 65% relative humidity for weak virus activity, and the UV-C lamps (254 nm) to finally inactivate AIV. Since AIV doesn’t like the high salinity and high relative humidity, seawater is blanketed as sprayer to maintain high salinity (>20 ppt) and high relative humidity (>65%) from the top to the bottom of the poultry farmhouses for suppression of AIV transmission from infected aeolian dust coming from outside.

Effectiveness of coal mine dust control:A new technique for preparation and efficacy of self-adaptive microcapsule suppressant

This study aims to make full use of the agricultural waste peanut shells to lower material costs and achieve cleaner production at the same time.Cellulose nanofibrils(CNF)extracted from peanut shells were mixed with acrylic acid(AA)and dimethyl diallyl ammonium chloride(DMDAAC)to prepare a new type of capsule core(dust suppressant).Then,the self-adaptive AA-DM-CNF/CA microcapsules were prepared under the action of calcium alginate.The infrared spectroscopy and X-ray diffraction analysis results suggest that AA,DMDAAC and CNF have experienced graft copolymerization which leads to the formation of an amorphous structure.The scanning electron microscopy analysis results demonstrate that the internal dust suppressant can expand and break the wall after absorbing water,featuring a self-adaptive function.Meanwhile,the laser particle size analysis results show that the microcapsules,inside which the encapsulated dust suppressant can be observed clearly,maintain a good shape.The product performance experimental results reveal that the capsule core and the capsule wall achieve synergistic dust suppression,thus lengthening the dust suppression time.The product boasts good dust suppression,weather resistance,degradation and synergistic combustion performances.Moreover,this study,as the first report on the development and analysis of dust-suppressing microcapsules,fills in the research gap on the reaction mechanism between dust-suppressing microcapsules and coal by MS simulation.The proposed AA-DM-CNF/CA dust-suppressing microcapsules can effectively lower the dust concentration in the space and protect the physical and mental health of coal workers.In general,this research provides a new insight into the structure control and performance enhancement of dust suppressants.Expanding the application range of microcapsules is of crucial economic and social benefits.

Experimental Study for the Cementation Effect of Dust Soil by Using Soybean Urease

Dust is an environmental and health hazard.In this study,a new technology for dust suppressant is introduced using soybean urease with an optimal cementing solution.Calcium carbonate is produced by soybean urease and cementing solution,which bonds the soil particles towards a dust suppressant.A laboratory wind tunnel test is carried out to examine its effectiveness and discover possible optimization solutions.Several factors,including soybean meal concentration,cementing solution concentration,and volume of solution per unit area,are examined to quantify their influences on soil transport mass,evaporation ratio,evaporation rate,surface strength,water retention ratio,and infiltration rate of soil treated by different dust suppressants.Field tests are conducted to explore the performance of this method in the natural environment.The results show that compared with other dust suppressants,the optimized soybean urease has the smallest evaporation rate,a moderate infiltration rate,the largest water retention ratio and surface strength.The indexes of soybean urease for dust suppressant are found to be better than traditional materials.In the natural environment,soybean urease has a stronger anti-disturbance ability.This study concludes that soybean urease dust suppressant has great application potential as a cheap and green method.

露天矿山爆破抑尘技术研究与应用

针对司家营铁矿爆破粉尘大、扩散慢、滞留时间长的特点,通过分析粉尘产生原因,对水雾覆盖抑尘机理及影响因素进行研究,优化采场爆破方式方法,改善爆破抑尘效果,同时建立爆破抑尘管理体系,做到爆区抑尘全覆盖。

工地扬尘化学防治技术研究进展

随着中国基础设施和城市化建设迅速发展,在施工过程中带来的扬尘污染日益增长,对工地扬尘采取防治措施十分必要,其中化学抑尘方法得到快速创新发展和应用。文章简要地介绍了中国扬尘来源、危害以及当前的主要防治方法,阐述了抑尘的启动和沉降过程,重点总结了湿润型、粘结型、凝聚型和复合型四类化学抑尘剂的作用机理、主要成分、新研究与工程应用,并分析了各类抑尘剂的优缺点。通过归纳总结化学抑尘剂的效果评价指标规范,探讨了化学抑尘法防治建筑工地扬尘存在的问题,提出化学抑尘剂的发展方向。

生物质改性制备抑尘剂研究进展

扬尘所引起的大气污染问题,对生态环境及人类健康所造成的危害日益突出,抑尘剂由于其高效的抑尘性能受到广泛关注。介绍了抑尘剂的分类、优缺点和应用场景,总结了近年来国内外生物质类抑尘剂的研究进展,分析了不同生物质在制备抑尘剂时的优劣势,并针对目前的不足,在测试标准、制备工艺、改性方法 3个方面做出进一步的研究展望。