水镁石的低温化学合成及其矿物学研究   总被引：1，自引：1，他引：0  

徐宝龙  郑永飞 《矿物学报》1998,18(3):273-280

在低温条件下应用氯化镁法、氧化铁法和氮化镁法三种不同化学方法合成了水镁石矿物,并对其进行了X射线衍射、扫描电镜和热分析研究。结果表明,三种不同方法合成的水镁石矿物的X射线衍射谱各有特点,对水镁石形貌的扫描电镜观察发现：氮化镁法合成产物呈六方板状;氧化镁法合成产物呈大的片状聚集体,但颗粒很小;氯化镁法合成产物多呈不规则粒状聚集体,粒度比较均匀。显然水镁石的形态受合成方法和条件的影响,特别氮化镁法合成的水镁石形状与温度有关,温度越高形状越复杂。差热和热重分析表明,氯化镁法合成水镁石的分解脱水特征温度比氧化镁法和氮化镁法合成水镁石的要低50℃左右,这可能与矿物颗粒的大小和形状有关。对这些合成水镁石的矿物学研究不仅具有材料科学意义,而且为研究天然水镁石成因和性质提供了实验室证据。  相似文献   

橄榄石的蛇纹石化,滑石化,水镁石化的热力学讨论   总被引：2，自引：0，他引：2  

李明德 《矿物岩石》1993,13(3):81-85

本文运用热力学的计算和分析方法,对橄榄石、斜顽辉石的蛇纹石化、滑石化、水镁石化进行研究,以期对其成矿理论和矿山开采时的综合利用提供一定依据。  相似文献   

四射珊瑚AuloPhyllum fungites骨骼微细构造的电镜研究     

王鸿祯  陈建强 《现代地质》1988,2(3):293

本文对Aulophyllum fungires （Fleming）,1828的骨骼微细构造进行了扫描电镜研究.结果表明,其骨骼纵列构造和横列构造全由纤状骨骼方解石晶针构成.晶针大小可分两级:大者在隔壁和横板中,大小近相等,其平均长度为32μm,平均直径为4μm;小者在鳞板,内斜板和柱隔壁中,其平均长度为10μm,平均直径2μm.晶针只在隔壁中沿轴部组成一排晶（?）,其平均直径为30—60μm,晶（?）两侧晶针组成晶束几近垂直,并间歇生长.在纵切面上,横板与隔壁相接处,间歇生长线是连续的,说明两者同步增长和形成过程相同.  相似文献   

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

DONG Faqin DENG Jianjun WU Fengchun PU Xiaoyong John HUANG FENG Qiming HE Xiaochun 《《地质学报》英文版》2006,80(4):589-596

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.  相似文献   

天然水镁石及其煅烧产物对臭氧化降解水中苯酚的效果研究   总被引：1，自引：0，他引：1  

何坤  董玉明  李真  尹琳  张爱民 《矿物岩石地球化学通报》2007,26(2):155-159

为有效去除工业废水中的苯酚,本文结合臭氧化技术,引入天然碱性矿物水镁石及其煅烧产物氧化镁作为催化剂,进行了催化臭氧化处理水中苯酚的研究。结果表明,加入的两种碱性矿物对臭氧化降解苯酚都有显著的催化效果。同时,碱性矿物的加入明显的改变了臭氧化过程中水体的pH值,从而对促进苯酚的降解起到了主导作用;除此之外,吸附实验及改变催化剂加入量的实验表明,碱性矿物表面对羧酸的吸附作用在一定程度上也导致苯酚降解效率的提高。本文工作为臭氧化降解水中苯酚提供了一种简便实用的处理方法,同时为天然水镁石矿物找到了新的应用领域。  相似文献   

纤维水镁石在无机铵盐中的溶解行为研究   总被引：2，自引：0，他引：2  

董发勤  John Huang  万朴 《岩石矿物学杂志》2000,19(3):212-219

纤维水镁石在水中可放出自由基,其在酸性环境中呈现化学活性,在体液环境中有细胞毒性。在水体环境中,它与一切释放出铵离子的物质反应并使自身发生溶解,其机理是可溶性铵盐在溶液中可离解出铵离子并放出质子,而水镁石在水中可电离出羟基。二价铁的存在使氧化还原反应常常伴生,最终形成三价铁铵盐复盐。因此,人体内的可溶性铵盐和体液中存在的铵离子可与水镁石粉尘作用并使之部分溶解。粒度增大和温度升高有利于镁元素在平衡体  相似文献   

纤维水镁石的环境安全性研究   总被引：2，自引：0，他引：2  

董发勤  万朴  周开灿  刘杰  罗素琼 《矿物岩石地球化学通报》1997,(1)

纤维水镁石的环境安全性研究＊董发勤万朴周开灿（西南工学院，绵阳６２１００２）刘杰罗素琼＊＊（陕南石棉矿，陕西宁强７２４４０１）（华西医科大学，成都６１００４４）关键词纤维水镁石环境矿物粉尘安全评估由于大量纤维日益广泛地应用于众多的工业领域，非职业接触...  相似文献   

纤维矿物生物活性研究的新进展   总被引：4，自引：0，他引：4  

李国武  董发勤  庄稼  万朴  彭同江  赵世泉 《四川地质学报》1998,(1)

石棉、毛沸石、硅灰石、坡缕石、海泡石、水镁石是被国际癌症研究所（ＩＡＲＣ）列为具有致癌、潜在致癌作用或具有较强生物活性的六种纤维矿物,本文综述了目前国内外对这几种纤维矿物生物活性的研究状况及最新进展  相似文献   

Pleistocene sea‐floor fibrous crusts and spherulites in the Danakil Depression (Afar,Ethiopia)     

David Jaramillo‐Vogel  Anneleen Foubert  Juan Carlos Braga  Jean‐Charles Schaegis  Balemwal Atnafu  Bernard Grobety  Tesfaye Kidane 《Sedimentology》2019,66(2):480-512

Pleistocene fibrous aragonite fabrics, including crusts and spherules, occur in the Danakil Depression (Afar, Ethiopia) following the deposition of two distinctive Middle and Late Pleistocene coralgal reef units and pre‐dating the precipitation of evaporites. Crusts on top of the oldest reef unit (Marine Isotope Stage 7) cover and fill cavities within a red algal framework. The younger aragonite crusts directly cover coralgal bioherms (Marine Isotope Stage 5) and associated deposits. Their stratigraphic position between marine and evaporitic deposits, and their association to euryhaline molluscs, suggest that the crusts and spherules formed in restricted semi‐enclosed conditions. The availability of hard substrate controls crust formation with crusts more often found on steep palaeo‐slopes, from sea level up to at least 80 m depth, while spherules mainly occur associated with mobile substrate. Crusts reach up to 30 cm in thickness and can be microdigitate, columnar (branching and non‐branching) or non‐columnar, with laminated and non‐laminated fabrics. Two different lamination types are found within the crystalline fabrics: (i) isopachous lamination; and (ii) irregular lamination. These two types of lamination can be distinguished by the organization of the aragonite fibres, as well as the lateral continuity of the laminae. Scanning electron microscopy with energy dispersive X‐ray spectroscopy analyses on well‐preserved samples revealed the presence of Mg‐silicate laminae intercalated with fibrous aragonite, as well as Mg‐silicate aggregates closely associated with the fibrous aragonite crusts and spherules. The variety of observed fabrics results from a continuum of abiotic and microbial processes and, thus, reflects the tight interaction between microbially mediated and abiotic mineralization mechanisms. These are the youngest known isopachously laminated, digitate and columnar branching fibrous crusts associated with a transition from marine to evaporitic conditions. Understanding the context of formation of these deposits in Afar can help to better interpret the depositional environment of the widespread Precambrian sea‐floor precipitates.  相似文献   

高温高压条件下水镁石相变的拉曼光谱研究     

王世霞  郑海飞 《矿物学报》2012,32(3):349-352

本文应用金刚石压腔装置结合拉曼光谱分析技术原位观测了高温高压条件下水镁石的结构变化特征。结果表明：常温升至300℃过程中,随温度升高,水镁石中表征H-O对称伸缩振动的3652 cm-1拉曼特征峰向低波数移动,拉曼特征峰波数与对应的体系温度呈现良好的线性相关关系。常温条件下体系加压过程中,当压力升高至1.19 GPa时,水镁石中表征H-O振动的3652 cm-1拉曼峰向高波数移动并逐渐消失,同时产生表征方镁石的1078 cm-1拉曼特征峰,表明水镁石脱水相变为方镁石。随后压力降低过程中,表征水镁石H-O振动的3652 cm-1拉曼特征峰没有重新出现,脱水相变过程不可逆。  相似文献