茫崖温石棉的纤维X光照相研究

茫崖石棉矿是我国大型超基性岩型温石棉矿床。温石棉作为一种矿物在宏观上可以是纤维状的,也可以是非纤维状的。但是,作为工业矿物的温石棉都是呈纤维状的。作者对茫崖温石棉进行了纤维X光照相,揭示了其结构特征,鉴定了温石棉的多型,测定了温石棉2M_(c1)和20_(rc1)的含量百分比,在个别样品中发现有极少量的副温石棉,一些样品中发现有Povlen型温石棉,这是在我国的温石棉纤维中首次找到Povlen型温石棉。     

波伏稜型(Povlentype)羟基纤蛇纹石的发现及意义

三年来,在对蛇纹石矿物学及矿床研究中,在四川石棉矿发现了波伏稜型(Povlcntype)(即直径>500)羟基纤蛇纹石,进行了较系统的矿物学工作,并用高分辨电镜获得了清晰的晶格象。之后,随着研究工作的进一步深入,于四川石棉矿又发现一种波伏稜型纤蛇纹石。本文对两种波伏稜型矿物做了对比研究,尤其是深入研究了波伏稜型羟基纤蛇     

我国温石棉的种类、结构及性能

本文系统地介绍了我国温石棉的种类、结构特点和重要的工业技术特性。研究结果表明,我国存在6种温石棉变种,其中波伏棱型正温石棉系国内首次发现。文中对我国温石棉主要性能进行的测试和研究,对温石棉的工业应用具有实际意义。     

温石棉尾矿活化产物制备纳米SiO_2实验研究

<正>纤蛇纹石石棉尾矿又称温石棉尾矿,是温石棉矿在选矿及加工过程中产生的尾渣。除了含有少量的短纤维温石棉外,主要由蛇纹石组成,蛇纹石族矿物属1∶1型三八面体层状硅酸盐。它的理想晶体结构可以描述为:每一结构单元层     

一种新的温石棉矿床类型——科马堤岩（Komatiite）型的地质特征

科马堤岩型温石棉矿床产于太古代绿岩带内。其蛇纹石矿物组合简单，利蛇绞石只出现IT多型。成矿过程中，Al表现出较大活动性，CaO大量带出，MgO／SiO2比率明显变化。Munro温石棉矿床是一个典型实例。     

4种天然温石棉致大鼠肺损伤及对HO-1和HSP-70的影响

探讨了我国四大矿区天然温石棉致大鼠肺部损伤作用及肺组织中HO-1和HSP-70的表达差异。从我国四大天然矿区采集4种天然温石棉,用扫描电镜、红外光谱和X射线荧光光谱分析其粉尘形貌、表面活性基团和化学组分。将90只初断乳SPF级Wistar大鼠,随机分为5组(甘肃阿克塞、青海茫崖、四川新康、陕西陕南温石棉组和生理氯化钠溶液阴性对照组),用2. 0 mg/m L温石棉粉尘悬液0. 5 m L(1次/月)对大鼠非暴露式气管内滴注染毒。于1、6、12个月分批处死大鼠6只,测定支气管肺泡灌洗液(BALF)中的乳酸脱氢酶(LDH)、碱性磷酸酶(AKP)和总蛋白(TP)含量,采用qRT-PCR检测肺组织中血红素氧化合酶1(HO-1)和热休克蛋白70(HSP-70) mRNA表达水平,采用western blot检测肺组织中HO-1和HSP-70蛋白表达水平。结果显示,阿克塞、茫崖和新康温石棉组LDH及各温石棉组AKP和TP在各时间点均比阴性对照组高(P 0. 05),且随染毒时间延长呈上升趋势(P 0. 05)。染毒1月时,各染毒组HO-1、HSP-70 mRNA和HO-1、HSP-70蛋白表达量比阴性对照组高(P 0. 05);染毒6月时,各染毒组比阴性对照组高,阿克塞和陕南温石棉组低于茫崖和新康温石棉组(P 0. 05);染毒12月时,阿克塞和陕南温石棉组高于茫崖和新康温石棉组(P 0. 05),茫崖和新康温石棉组低于阴性对照组。     

包头矿晶格象的观察与分析

晶格象是一种二维结构的图象,能够在晶胞级上直观地反映出有关格子面的信息。本文利用EM400型电子显微镜对具有孤立四方环硅氧四面体群结构的包头矿的晶格象进行了观察与分析,得到了两组主要格子面的晶格象,观察到可能的双晶图象和位错现象,在此基础上分析了包头矿的解理和辐射损伤现象。     

集安石棉矿床地质特征及其成因探讨

集安石棉矿床,以往一直被认为属白云岩型蛇纹石石棉矿床。但该矿床的成因与国内外这类矿床迥然不同。典型的白云岩型蛇纹石石棉矿床的成因,都毫无例外的与中基性脉岩或酸性侵入体密切相关,受接触变质作用,为中温热液交代形成的石棉矿床。该矿床则是在区域变质作用的基础上进一步发展的结果,即区域混合岩化作用形成的。蛇纹石和石棉形成时的二氧化硅和结晶水来源于混合热液,氧化镁来自围岩(白云质大     

我国四大矿区温石棉粉尘诱导A549细胞凋亡和周期阻滞的对比研究

通过FT-IR和XRD对四川新康、陕西陕南、甘肃阿克塞和青海茫崖四大矿区温石棉的物相成分、谱学特征进行测试分析,利用MTT法、流式细胞术检测了4种温石棉纤维粉尘染毒A549细胞后的细胞存活率、凋亡率和细胞周期分布,比较和探讨了四大矿区温石棉纤维粉尘抑制细胞增殖能力的大小及其对细胞凋亡和周期阻滞的影响。研究结果显示,四大矿区温石棉的主要物相是斜纤蛇纹石,新康温石棉成分比其他3种温石棉的复杂,阿克塞和茫崖温石棉的成分相似;四大矿区的温石棉化学基团基本相同,阿克塞和茫崖温石棉纤维的表面结构较陕南和新康温石棉的完善。4种温石棉均能不同程度地抑制A549细胞增殖,诱导细胞凋亡和周期阻滞:茫崖组凋亡率最大(22. 56±2. 56)%,陕南组凋亡率最小(19. 57±3. 07)%;细胞周期阻滞均以G2/M期阻滞为主,新康、陕南、阿克塞和茫崖组处于G2/M期细胞比例分别增加8. 90%、8. 58%、9. 13%和10. 44%。4种温石棉导致细胞凋亡和周期阻滞的能力:茫崖新康阿克塞陕南。     

氟碳钙铈矿及B_2S规则混层矿物型体间共晶格取向连生的透射电镜研究

共晶格取向连生或体衍生是钙稀土氟碳酸盐矿物的重要特征。本文报道了该系列矿物中氟碳钙铈矿不同多型体间的8种共晶格取向连生以及B_2S规则混层矿物两种多型体间共晶格取向连生现象的研究结果。这9种共晶格取向连生现象均为首次发现。电子衍射和晶格象研究表明,在钙-铈氟碳酸盐B_mS_n型系列矿物中共晶格取向连生的微结构特征及其变化相当复杂。     

纤蛇纹石石棉的纳米效应与生物活性

本文首次从纳米材料与纳米效应角度出发讨论了纤蛇纹石石棉的形态、表面结构、表面性质与生物活性的关系。结果表明,纤蛇纹石石棉属自然界产出的一种特殊的一维纳米丝状矿物,在形态、结构和表现性质等方面表现出纳米材料所具有一般特性,其中,形态上一寸及高表面化学活性构成了它的生物活性特征。纤蛇纹石石棉纤维对动物的危害,既具有一般纤维的危害性,又具有非晶质ＳｉＯ２的危害性。由于纤维的小尺寸效应和高表面活性而使生物     

Asbestos and other fibrous minerals contained in the serpentinites of the Gimigliano-Mount Reventino Unit (Calabria,S-Italy)

Serpentinites are metamorphic rocks with good technological properties and valuable ornamental characteristics, which have been exploited since ancient times. Actually, their use is limited and monitored in several countries worldwide because they can contain fibrous asbestos minerals that may be carcinogenic. Furthermore, certain types of fibrous minerals can be confused with asbestos, and must therefore be carefully investigated. We have investigated the possible presence of the asbestos and non-asbestos fibrous phases contained in serpentinitic rocks in a meta-ophiolitic sequence from the Gimigliano-Mount Reventino Unit (Southern Italy), which had not been previously assessed. The detection and quantification of asbestos and the correct distinction of the fibrous non-asbestos minerals are very important not only from a scientific point of view, but also from a legislative one. This is especially the case for the administrative agencies that have to take decisions with regards to the implementation of public and occupational health protection measures (e.g., in road yards and quarry excavations). As a consequence of this, serpentinitic rock samples have been characterized in detail through X-ray powder diffraction, scanning and transmission electron microscopy combined with energy-dispersive spectrometry, analytical electron microscopy (SEM–EDS and TEM–AEM), differential scanning calorimetry, thermogravimetry and micro-Raman spectroscopy. Two kinds of asbestos and four kinds of non-asbestos fibrous silicates have been detected in the examined samples. In order of decreasing abundance these are polygonal serpentine, chrysotile, fibrous antigorite, tremolite, gedrite and magnesiohornblende. The size, morphology, crystallinity and chemical composition of the fibres were also discussed, in the light of the possible role these properties could play in the carcinogenic effect on human health.     

Identification of chrysotile in local soil at Beypinari village (Sivas-Turkey) regarding mine and health issue

Asbestos is dangerous for health and is forbidden to use in Turkey, but villagers who live in rural eastern part still use it especially for their home for insulation purposes and even as a substitute for baby powder. Therefore, geological and chemical properties of this type of soil, which is near the settlement, should be characterized and identified from the point of view of health. Beypinari asbestos deposits are located at Beypinari village, about 90 km southeast of Sivas, Turkey within Central Anatolian Ophiolites. Therefore, in the present study, the existence of chrysotile in Beypinari asbestos deposit were characterized and identified by mineralogical analysis and by major, trace, REE analysis. The results show that the samples contain different amount of calcite mineral, the main mineral being chrysotile.     

Chrysotile asbestos fibres from Quebec: electron magnetic resonance identification

Quebec chrysotile asbestos fibres have been examined by EPR spectroscopy at room T and 77 K. Finely divided samples show an absorption due to manganese(II) at g = 2.0with a hyperfine coupling of 90 gauss. Several types of ferric ions are present in addition to magnetite. These include surface adsorbed hydroxides and lattice bound ions. From the EPR spectrum of structurally bound iron in long fibres oriented perpendicularly to the magnetic field, it was found that the ferric ions are in a rhombic environment. EPR thus shows promise as a tool for the identification and characterization of asbestos fibres.     

Minerogenic Model of Chrysotile Deposits in Ultramafic Rocks

Most chrysotile deposits occur in ultramafic rocks of the ophiolite suite. The chrysotile deposits dis-cussed in the present paper were formed through metasomatism and infilling-crystallization in a continentalserpentinization environment after plate convergence, where ultramafic rocks were replaced byhydrothermal solutions consisting mainly of deep-circulating heated water derived from atmospheric precip-itation. The critical state for the formation of asbestos in ultramafic rock bodies might be reached bysuperposition of multiple stages of serpentinization. Favourable fracture systems and relatively stable geo-logical environment are important conditions for forming chrysotile deposits. Three subtypes of chrysotiledeposits could be formed in different tectonic settings and under different minerogenic geochemical condi-tions.     

水热条件对纤蛇纹石纳米管合成的影响研究

采用水热法在不同反应条件下合成了一系列纤蛇纹石纳米管.利用红外吸收光谱、扫描电镜和透射电镜系统地研究了水热反应中,反应温度、Si/Mg比、反应时间等不同反应参数对合成纤蛇纹石纳米管的晶体生长及其结构的影响.结果表明,温度的升高、Si/Mg比趋近0.68及反应时间的延长均有利于纤蛇纹石的生长,并获得最佳条件下合成的纤蛇纹石条件.     

Quality of chrysotile asbestos and high-temperature conductance of the host ultramafics: possible linkage

The paper reports physical, physicochemical, and mineralogical-petrographic studies of serpentinite samples from the Bazhenovo deposit of chrysotile asbestos. The samples differ in mineralogy, physical and physicochemical parameters, and in quality (fiber tenacity) of the hosted chrysotile asbestos. The experiments allowed estimating the temperature dependence of electrical resistance of serpentinites in a range of 20 to 800 °C, the parameters of their high-temperature resistance (the activation energy E₀ and the resistance coefficient lg R₀), and the relationship between fiber tenacity of asbestos and high-temperature conductance of the host serpentinites. The serpentinite samples that host brittle and tenacious chrysotile asbestos plot different fields in the coordinates E₀–lg R₀ without any overlap. Thus, the quality of chrysotile asbestos can be inferred from the parameters of high-temperature conductance of the host serpentinites.     

Asbestos in lake and reservoir waters of Staten Island,New York: Source,concentration, mineralogy,and size distribution

There is strong evidence indicating that the six commonly recognized varieties of asbestos are cancer-producing agents Epidemiological and experimental data indicate that, although response to inhalation exposure is most marked, exposure by ingestion probably also entails a risk of excess tumor incidence. The toxicity of mineral fibers can be related to fiber dimensions, mineralogy, chemistry, and surface-active properties. In the Silver Lake Reservoir in Staten Island, New York, where chrysotile from serpentinite bedrock exposures is a potential source of contamination, chrysotile asbestos levels of 15 to 86 million fibers per liter (MFL) were measured, with an average of 53 MFL Much lower levels (average 0 3 MFL) were observed in small lakes and ponds with clayey bottoms on the Staten Island Serpentinite.