The Mineralogy and Possible Sources of Spring Dust Particles over Beijing

A severe Asian Dust Storm （ADS） event occurred on 16-17 April 2006 in northern China. The mineral compositions of dust samples were analyzed using X-ray diffraction （XRD）. The results indicated that dust particles of the ＂17 April 2006＂ dust storm were dominated by quartz （37.4%） and clay （32.9%）, followed by plagioclase （13.7%）, with small amounts of calcite, K-feldspar, dolomite, hornblende and gypsum （all less than 10%）. The clay fractions with diameter less than 2 μm were separated from the dust storm particles by centrifuging and were further analyzed by XRD. The results revealed that the clay species were mainly illite/smectite mixed layers （I/S） （49%） and illite （34%）, with small amount of kaolinite （8%） and chlorite （9%）. In order to evaluate the feasibility of using the mineralogy to trace the sources of dust particles, the XRD results of the ＂17 April 2006＂ dustfall particles were compared with the dust particles over past years. The results confirmed that the finer dust particles represented by the ADS PM10 displayed a smaller quartz/clay ratio than the dustfall particles. The dust storm particles, either from the ADS PM10 or from the ＂17 April 2006＂ dustfall, showed a lower level of dolomite contents and lower dolomite/clay ratios compared with the non-dust storm dustfall particles. This implies that dolomite could be used to distinguish between the dust contributions from local and non-local sources. Similar trends were found for the gypsum and the gypsum/clay ratio. Moreover, the two dustfall samples had a lower level of illite/smectite mixed layers and a higher level of illite than airborne PM10, implying that the dustfall particles tend to be enriched with illite in its clay fraction.

Assemblage characteristics of clay minerals and its implications to evolution of eolian dust input to the Parece Vela Basin since 1.95 Ma

To understand the provenance and evolution of eolian input in the last 1.95 Ma in the Parece Vela Basin in the eastern Philippine Sea, the clay mineral assemblage of a gravity core PV090510 from the basin was investigated using paleogeomagnetic dating and X-ray diffraction. The assemblage of the core mainly consisted of smectite （-46%） and illite （-40%）, with some chlorite （-10%） and kaolinite （-4%）. Analysis of the provenance of these minerals suggested that smectite was mainly derived from volcanic rocks of the Mariana Arc, while illite, chlorite, and kaolinite were mainly transported as eolian dust by the East Asian monsoon from central Asia. We used the ratio of （illite＋chlorite＋kaolinite）/smectite as a proxy for Asian eolian input to the Parece Vela Basin since 1.95 Ma. This ratio followed glacial and interglacial cycles and was consistent with the intensity of the East Asian monsoon and aridity of central Asia since 1.95 Ma. The changes of the ratio reflected three different stages of the East Asian monsoon and provenance climate.

Effect of Mineral Dusts on the Growth of Silicate Bacteria S35

In order to compare the chemical compositions and physical properities of dusts on silicate bacteria S35, the chemical compositions of six kinds of mineral dusts have been analyzed and the changes of pH value, glucose （GLU）, electrolyte and Mn, Si, Fe before and after the dusts reacted with silicate bacteria S35 have been measured. The SEM analysis has been used to study the bacterial form and interface action status in the course of reaction between dusts and bacteria. The results show that these mineral dusts have different effects on experiment bacteria. Therefore, it is concluded that the effect of mineral dusts on silicate bacteria has correlation with the chemical compositions and physical properities of dusts.

The Study on Genotoxicity of PM_(2.5) Mineral Dusts to A_(549) Cells

By detecting the influence of six main ingredients of PM2.5 mineral dusts on the A549 cell morphology, proliferation inhibition rate, micronuclei and DNA damage, to explore the genotoxicity of PM2.5 mineral dusts. (1) After exposure to six kinds of dusts of 200 μg/mL concentration for 24 hours, the morphology of A549 cells were observed using Wright-Giemsa staining. (2) After exposure to different concentrations of mineral dusts for 24 hours, the proliferation inhibition rate of A549 cells was detected by MTT assay. (3) Cells were exposed to PM2.5 mineral dusts at a concentration of 200 μg/mL for 24 h. After Wright-Giemsa staining, the rates of micronucleus cells were counted under oil microscope. (4) Observe Comet phenomenon by SCGE electrophoresis, the degree of DNA damage was observed by OTM. (1) Compared to the control group, membrane destruction, nuclear pyknosis and mineral surface adhesion were mainly seen in the Sericite group and Albite group. In the Quartz group and Montmorillonite group, enlarged cell gaps, loosely arranged cells, absorption of a large number of minerals on the cell surface, and cell pyknosis were observed. (2) The proliferation inhibition rate of the six kinds of dusts to A549 cells were (from large to small): KWC-M>Nano-SiO2>KWC-S>KWC-Q>KWC-A>KWC-C.The dust concentration was positively related to the inhibition of cell proliferation rate. (3) With the dusts concentration increased, the incidence of micronuclei gradually increased. The rate was positively correlated to exposure concentration. (4) The six mineral dusts can damage DNA of the A549 cells by dose-response relationship.The higher concentration of the mineral dusts, the more obvious of the DNA damagenation. There’s statistically significant compared with the control group. The six main ingredients of the PM2.5 mineral dusts can change A549 cell morphology from varying degrees, improve proliferation inhibition rate of the cells, increase the number of micronuclei cells, damage DNA.Then we come to the conclusion that PM2.5 mineral dusts can change the genotoxicity of the cells.

Mineralization and Cementation of Fugitive Dust based on the Utilization of Carbon Dioxide and Its Characterization

Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared（FTIR） spectroscopy, and differential scanning calorimetry-thermogravimetry（DSC-TG）. The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.

Simulation of the Direct Radiative Effect of Mineral Dust and Sea Salt Aerosols in a Doubled Carbon Dioxide Climate

The authors examine the equilibrium climatic response to the direct radiative effect （DRE） of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In response to the drier and windier conditions,dust emissions increase by 26％ in the Sahara Desert and by 18％ on the global scale relative to present day.Sea salt emissions increase in high latitudes （＞60°） but decrease in middle latitudes （30°-60°） of both hemispheres due to the poleward shift of westerlies,leading to a 3％ decrease in global emissions.The burdens of dust and sea salt increase by 31％ and 7％ respectively,because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate.The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2,leading to an additional cooling of 0.1℃ at the surface compared with the climatic effects of aerosols in present day.The additional cooling from changes in natural aerosols compensates for up to 15％ of the regional warming induced by doubled CO2.

Investigation on the surface active sites variation of mineral dusts

The paper analyzed the groups naked and the transformed of fibrous brucite, wollastonite, chrysotile asbestos, sepiolite, palygorskite, clinoptilolite, crocidolite and diatomaceous earth mineral dusts by using IR under acid and alkali etched, strong mechanical and polarized molecular interaction. The results show that the active site focuses on ends in stick dusts and on defects or hole edges in pipe dusts. The inside active sites of dusts play the main role in small molecular substance. The shape of dusts affects their distributions and densities of active sites. The strong mechanical and weak chemical force make the active site feature of minerals change, the powder process brings about more naked surface groups and more combined types. The dust activity relates to the type, contribution, and naked level of surface groups. The studied dust surface groups are mainly as follows: OH?, Mg(OH)?, Si-O-Si, Ca-O-Si, -Mg-OH2,-Al(Si)-OH, -Mg(Ca)-OH2, Ca-O,-Si???OH, Mg(Fe)-OH. Due to the difference of surface composition and structure, the minerals have a large disparity on activity and character of surface groups. The one side surface group of chrysotile layer is the same as fibrous brucite and stripped layer with more naked group. The fibrous sepiolite and palygorskite surface OH? similar to crocidolite is naked with their surface structural defects and cleavage. The more development of mineral defects, the higher of OH? (H2O+) content, the main H2O+ of clinoptilolite is partly transformed into H+, NH 4 + or OH?. The acid etched process may change OH? concentration, distribution and increase the defects and porosity of mineral fiber surface. The alkali etched has no effect on Si-O, Si-OH etc. and destroyed Al-O, Al-OH? acid site of sepiolite, palygorskite and clinoptilolite. Some surface groups of remnant differ from original dusts. The surface process of small polarized molecular or middle moleular’s branch may produce ionation and new coordinate bond, and change the active properties and level of original dusts, such as the porous minerals producing

FURTHER STUDIES ON THE MALIGNANT TRANSFORMATION OF SYRIAN GOLDEN HAMSTER EMBRYO CELLS IN VITR0 BY THORIUM DIOXIDE AND RARE EARTH IRON MINERAL DUSTS

Malignant transformation of hamsterembryo cells was induced in vitro by rareearth iron mineral dusts(MP),naturalthorium(Th02) and MP plus Th02.Dusts of MP,MP plus Th02 or Th02 were added into themedium with the final concentration of 17.0,

How relevant are engineering samples in the management of personal dust exposure?

A directive, legislated by the South African Department of Minerals and Energy(DME) in 1997, was introduced to reduce the dust exposures of continuous miner(CM) operators to below 5 mg/m3, when measured at the operator's cab position. The focus of this paper is to review the effectiveness of observing this rule for almost two decades and discuss industry perceptions arising from the application of this rule. The results have demonstrated that the engineering sample cannot predict the personal shift dust exposure of a CM operator. Therefore, it is recommended that the engineering sampling, as currently practiced,should be reviewed with the objective to discontinue and replace it by the approved PDM3700 realtime dust monitor.

Individual Aerosol Particles Emitted in the Ceramic-Tile Industry in Chihuahua, Mexico

The contribution of anthropogenic mineral aerosol dust has been of interest to understand the impact of dust aerosols on climate, and the health of workers occupational exposure. Several studies have been investigated the physical and chemical properties mainly in particulate matter. However, the characterizations have not extended diameters below to 1.0 μm. In this study, it described chemical composition and shape measurements of individual aerosol particles with 50% cut-off diameters less than 1.1 μm emitted at ceramic-tile manufacturing. Four emission sites of process were selected, and their samples were collected using a cascade-impactor, investigated using X-ray diffraction, energy dispersive X-ray spectroscopy, and digital image processing, where the data were analysed applying a combination of principal component and cluster analysis. Particles of tectosilicate （quartz, zeolite）, phyllosilicate （illite, montmorillonite）, and inosilicate （calcium silicate） were founded in all sampling sites; also, silicates mixed with transition metals oxides used as pigments （e.g., Fe, Ti, Co, Ni, Zn and Mo）. Silicates were granulated and flat crystals with a transparent, translucent appearance; otherwise, the mixture had flake shapes and opaque appearance. Analyses of multivariate data showed that the process stages emissions were related with specific composition and shape suggesting the use three measurements related （1） the internal axis, （2） roundness and （3） roughness to isolate particles shapes, and the presence of transition metals oxides as emissions tracer of the ceramic industry.

A Study on Cellular Reactions and Fibrogenic Effectsof Mineral Dusts

In vivo cytotoxicity including cellular metabolic activity, lysozyme content and total protein content in rat bronchoalveolar lavage, capacity of interleukin-1 released from rat pulmonary cells and fibrogenic effects evaluated from rat lung dry weight, collagen content of the whole lung and pathological grading induced by mineral dust were assayed. The results showed that: (1) The relationship among in vivo cytotoxicity, interleukin-1 release,fibrogenic effects on the lung induced by mineral dusts correlated well with the free SiO2content in mineral dusts in most (but not all) cases; (2) The biological harmful effects of mixed dusts were not simply the additive effect of single dust. In the group of WO3-SiO2mixture, the fibrogenicity was mainly due to SiO2, tungsten trioxide (WO3) showed neither fibrogenic effect, nor significant potentiality to enhance SiO2 fibrogenicity, while in the group of SnO2-SiO2, SnO2 was suppressive to the effect of SiO2, although the contents of SiO2 in the two mixed dusts were similar

Mineralogy and Possible Sources of Dust Particles During One Asian Dust Episode

A severe Asian Dust Storm(ADS)event occurred on April 16-17th,2006 in northem China.Mineral components of dust samples were analyzed using X-ray diffraction(XRD).The result indicates that dust particles were dominated by quartz(37.4%)and clay (32.9%),followed by plagioclase(13.7%),with small amounts of calcite,K-feldspar,dolomite,homblende, and gypsum(all【10%).The clay fractions with diameter less than 2μm were separated from the

An In Vitro Investigation of Pulmonary Alveolar Macrophage Cytotoxicity Introduced by Fibrous and Grainy Mineral Dusts

In order to study the damage mechanism of mineral dusts on the pulmonary alveolar macrophage （AM）, the changes in their death ratio, malandialdthyde （MDA） content and activities of lactate dehydrogenase （LDH） and superoxide dismutase （SOD） were measured, and the technique of cell culture in vitro was used to investigate the cytotoxicity of six mineral dusts （twelve crystal habits） from twelve mineral deposits. The results show that woUastonite and clinoptilolite have no AM cytotoxicity, while other fibrous and grainy mineral dusts damage pulmonary AM in various degrees. The cytotoxicity of fibrous mineral dusts was greater than that of the grainy ones, and the cytotoxicity of dusts was positively correlated with the active OH- content in dusts, but not necessarily so with its SiO2 content. The high pH values produced by dust was unfavorable for the survival of cells and the dusts with low bio-resistance were safe for cells. The content of variable valence elements in dusts might influence their cytotoxicity and the surface charge of dusts was not a stable factor for their toxicity. It is demonstrated that the shape of mineral dusts was one of the factors affecting cytotoxicity, and that the cytotoxicity of mineral dusts depends mainly on their properties.

Aerosol absorption optical depth of fine-mode mineral dust in eastern China

The fine-mode aerosol absorption optical depth（AAOD）retrieved from the Aerosol Robotic Network（AERONET）has been used in previous studies to calculate the radiative forcing of black carbon（BC）aerosol,assuming that the absorption by fine-mode aerosols（diameter ≤ 1 μm）is primarily from BC while the absorption by larger particles（diameter 1 μm）is principally from dust.In the present study,the Community Earth System Model was used to simulate and quantify the contribution of fine-mode dust to fine-mode AAOD in eastern China（29–41°N,104–122°E）—an area where concentrations of BC are high.The simulated fine-mode dust concentrations were constrained by observations from nine sites belonging to the Chinese Meteorological Administration Atmosphere Watch Network.Averaged over eastern China,the simulated annual mean fine-mode dust AAOD was 3.6 × 10-3,with the maximum AAOD in spring and the minimum value in winter.The contribution of fine-mode dust to the total fine-mode AAOD（sum of fine-mode dust,BC,and organic carbon）in winter,spring,summer,and autumn was 3.4%,25.2%,12.5%,and 14.9%,respectively,with an annual mean value of 15.1%.The results indicate the importance of removing fine dust AAOD when the AERONET fine-mode AAOD is used for calculating the radiative forcing of BC in eastern China.

Mechanism for the promotional formation of NH_(4)^(+) by SO_(2) on different mineral dust surfaces

Ammonium is an important atmospheric particulate component that dictates many environmental processes.The promotion of the heterogeneous conversion of NH_(3) to NH_(4)^(+) by SO_(2) on different mineral dust surfaces displays remarkable discrepancies,especially on MgO and α-Fe2O3 surfaces,however,the underlying mechanisms are not well known.Here,using periodic density functional theory(DFT)calculation and Born-Oppenheimer molecular dynamics(BOMD)simulation,we explored the hetero-geneous adsorption of NH_(3) on MgO(110)and α--Fe2O3(001)surfaces in the presence and absence of SO_(2).The results show that on MgO(110)surface,hydrogen-bonding interactions of NH_(3) on both adsorbed hydroxyl or bisulfite/bisulfate sites are observed no matter whether SO_(2) is present or not.While,on theα-Fe2O3(001)surface,significant conversion of NH_(3) to NH_(4)^(+)occurs with the coexistence of SO_(2),which is due to the hydrogen transfer reaction from surface HSO4 to N in NH_(3).The fundamental reason may be that the stronger electron affinity of Fe3+than Mg2+results in adsorbed bisulfate and/or bisulfite with greater acidity on α-Fe2O3 surface than MgO surface.Our results give a molecular-level explanation for the heterogeneous conversion of NH_(3) to NH_(4)^(+)on different mineral dust surfaces under complex air pollution conditions.Considering the fact that ammonium is abundant in secondary particulates,this work would help in understanding the rapid conversion of ammonia to ammonium and in developing classification governance policies for the key precursor pollutants in China.

矿物粉尘环境下矿井缠绕提升钢丝绳振动磨损特性研究

针对矿物粉尘易黏附于具有润滑保护的矿井缠绕提升钢丝绳表面而影响其接触磨损过程问题,利用自制缠绕提升钢丝绳振动磨损测试平台,分析矿井中常见矿物粉尘(煤炭颗粒和矿石颗粒)对缠绕接触钢丝绳间的摩擦学参数演化规律,并揭示其对钢丝绳磨损过程的干扰机制,以期为矿井提升系统的运维及延长钢丝绳使用寿命提供基础数据支撑.结果表明:随着煤炭颗粒体积分数从10%增至40%,钢丝绳在相对稳定阶段的平均摩擦系数从0.158增至0.173,而颗粒尺寸的增大则使其呈现出相反的变化趋势;此外,随着煤炭颗粒体积分数不断增加,钢丝绳磨损表面C元素含量越来越多,黏附效应越来越严重,且剥层现象也越来越明显;随着矿石颗粒体积分数增至40%,钢丝绳摩擦系数增至0.157,磨损深度增至120.4μm,且相比于煤炭颗粒,钢丝绳摩擦系数曲线更加平稳,而颗粒尺寸则与摩擦系数和磨损深度负相关;矿石颗粒浓度的增加及尺寸的减小均导致钢丝绳接触表面磨粒磨损程度更加严重.

极寒地区室内矿石转运产尘密封净化性能研究

极寒地区选矿车间密闭性强,室内矿石转运环节产尘聚集度高,威胁作业人员职业健康和电器设备运行安全。以我国东北某金属矿磨浮车间矿石转运过程为例,在研究矿石粉尘理化特性的基础上,提出了新型导料槽密闭抽尘与气液卷吸除尘器除尘协同的粉尘控制方案,研究了导料槽密闭抽尘系统对转运扬尘的封闭性能,探讨了气液卷吸除尘器对收集的含尘气流的净化能力。结果表明:钼矿石转运点外逸粉尘粒径集中分布于0.2~3.0μm,且具有较强的亲水性,游离二氧化硅含量高达48.6%,属于矽尘范畴;导料槽密闭抽尘系统在过料口风幕隔离和导流作用下,有效抑制了转运点粉尘外逸,转运点附近全尘和呼尘浓度较使用前分别下降了61.1%和50.0%;气液卷吸除尘器在剪切液幕和卷吸气泡2种流型下具有较好的除尘效果,对转运点钼矿石粉尘的除尘效率可达92.8%~96.3%。研究成果和现场实施经验可为我国北方极寒地区封闭车间粉尘治理提供有益借鉴。

酒钢选矿厂含铁除尘灰资源化利用研究

以酒钢选矿厂含铁除尘灰为研究对象,研究环境除尘灰和烟气除尘灰的选矿技术经济指标,进行除尘灰用于水泥生产物料性质测试,分析用作铁质校正剂的可行性。通过不同应用途径的可行性和经济性分析,为选矿厂合理处置除尘灰提供了依据。

褐煤粉尘对矿区复垦土壤有机碳矿化及细菌群落的影响

煤粉尘沉降至地表后能够显著提高土壤有机碳含量,改变土壤理化性质和土壤微生物群落结构。通过添加褐煤粉尘的土壤培养试验,探究煤粉尘输入的有机碳对土壤有机碳矿化效果及细菌群落的影响。结果表明:在褐煤粉尘影响下,土壤CO_(2)矿化量和矿化速率较对照组最大提升55.02%和54.58%(第5天);土壤易氧化有机碳和土壤微生物生物量碳含量在培养结束后较最大值分别降低40.75和141.39 mg/kg。添加褐煤粉尘导致变形菌门的相对丰度显著降低,而酸杆菌、放线杆菌和厚壁菌门的相对丰度升高。褐煤粉尘输入的有机组分能够在短期内产生激发效应,其自身被土壤细菌分解的过程也能促进土壤CO_(2)的矿化累积,并且提高土壤细菌群落的多样性和变异程度。褐煤粉尘中的有机碳极大程度参与了土壤有机碳库周转过程。

矿山防尘降尘设施的改进措施探究

在当前可持续发展战略深入推进的大背景之下,对于矿产矿山行业而言,需要在节能环保方面进行有效加强,要匹配高质量的防尘降尘设施,并且对其进行不断改进和切实优化,这样才能有效减少粉尘污染,为矿产矿山行业取得更加良好的发展成效提供必要条件。同时也要在综合性技术方面进行切实优化,匹配更切实可行的设施设备及先进技术,这样才能切实减少其使用过程中可能存在的各类环境污染问题,对于人员和环境进行更有效保护。因此,相关企业需要在设施改进措施等方面进行不断优化和切实完善,有效控制各类污染,从而为矿产矿山行业的可持续发展奠定坚实基础。基于此,本文重点探究矿产矿山防尘降尘设施的改进措施等相关内容。