运城盐湖芒硝除钙镁方法研究与分析          下载免费PDF全文

孙培霞 《盐湖研究》2007,15(4):45-48

就南风化工集团运城区域元明粉生产过程中遇到的水硝含钙镁高的问题,对各种除钙镁方法进行研究、分析和对比,最终得到一种经济实用的除钙镁方法。  相似文献   

海底沉积物中碳酸钙分析方法的研究   总被引：4，自引：0，他引：4  

宋苏顷  夏宁 《岩矿测试》1998,17(2):127-130

探讨了海底沉积物中ＣａＣＯ３的测定方法。用１ｍｏｌ／ＬＮａＡｃ＋ＨＡｃ做碳酸盐相＋离子交换相的浸取剂,１ｍｏｌ／ＬＮａＡｃ做离子交换相的浸取液,在沸水浴中３０ｍｉｎ分解样品,然后用ＡＡＳ或ＩＣＰＡＥＳ分别测定离子交换相＋碳酸盐相及离子交换相中的Ｃａ,差减法计算样品中ＣａＣＯ３含量。方法经深海沉积物、水系沉积物等国家标准物质验证,结果与标准值相符。对同一样品进行１２次测定,相对标准偏差小于５％。  相似文献   

Temperature dependence of δLi, δCa and Li/Ca during growth of calcium carbonate     

Caedmon S Marriott  Gideon M Henderson  Nick S Belshaw  Alexander W Tudhope 《Earth and Planetary Science Letters》2004,222(2):615-624

Lithium and calcium isotope ratios, together with the Li/Ca element ratio, have been measured in calcites precipitated inorganically at temperatures ranging from 5 to 30 °C, and on seasonal growth bands from a coral. These measurements indicate the potential uses of these three environmental proxies. Carbonate Li isotopes are lighter than the solution from which they grow, probably due to equilibrium fractionation. This fractionation is not significantly influenced by temperature and, because Li is not involved in any known biological process, this suggests that carbonates will provide a recorder for the past Li-isotope composition of natural waters and hence for past weathering conditions. As has been observed previously for inorganic aragonite, the Ca-isotopes in inorganic calcite are lighter than the growth solution, and are only weakly dependent on temperature. This confirms that the temperature dependence observed in some species of foraminifera [Geochem. Geophys. Geosyst. 1 (2001)] reflects additional isotope fractionation due to biological processes during mineralization. Ca isotopes may therefore provide a powerful tool with which to investigate the processes of biomineralization. Finally, Li/Ca ratios in inorganic and biogenic carbonates increase as temperatures decrease with a sensitivity of ≈4% per °C. This temperature dependence of Li/Ca may prove useful to assess past temperatures in cold environments such as the deep ocean.  相似文献   

钙磷酸盐—BMP多孔复合材料的降解与成骨效应     

黄学辉  孙淑珍  吕明  石晓兵  梁克玉 《矿物学报》2001,21(3):364-368

通过X射线照相术、SEM、EPMA等测试手段研究了钙磷酸盐（CP）多孔陶瓷及钙磷酸盐－骨形态发生蛋白质（BMP）多孔复合材料（CPB）在动物体内的生物降解性、成骨效应以及材料－骨界面的显微结构。用统计学τ检验对CP和CPB两种材料植入体内后的新骨形成速率数据进行了处理。结果表明CPB复合材料的新骨形成速率明显高于CP陶瓷；钙磷酸盐矿物有较好的生物降解性，但在体内完全降解是不可能的；BMP与CP复合后，能明显地加快新骨形成，促进钙磷酸盐矿物的降解；多孔结构亦有利于矿物降解及新骨形成，新骨长入陶瓷孔隙后形成一中种互穿网络结构，使植入部位力学性能得到强化，弥补了材料降解中所导致的力学性能的衰减。据此可以预测，通过适当的孔结构和诱导成骨机制，可以制备出近乎完全降解的生物材料。  相似文献   

土壤pH值及CaCO_3在多目标地球化学调查中的研究意义     

朱礼学  邓泽锦 《物探化探计算技术》2001,23(2)

深覆盖区多目标地球化学调查 ,旨在通过土壤地球化学测量 ,为农业、环境、矿产资源评价及基础地质研究服务 ,作者重点阐述了土壤 p H值、Ca CO3含量与土壤矿质元素活化之间的制约机理 ,论述深覆盖区多目标地球化学调查要实现服务于农业、服务于生态环境保护的目标 ,就必须加强对土壤 p H值及 Ca CO3含量调查研究。  相似文献   

The Calcium Isotope Composition of Modern Seawater Determined by Thermal Ionisation Mass Spectrometry   总被引：1，自引：0，他引：1  

Anne-Désirée Schmitt  Guido Bracke  Peter Stille  Bernard Kiefel 《Geostandards and Geoanalytical Research》2001,25(2-3):267-275

The Ca isotopic composition of modern seawater has been determined using a ⁴³Ca-⁴⁸Ca double spike, which was calibrated using a ⁴²Ca/⁴⁴Ca seawater ratio of 0.30587 ± 0.00026. This ratio was determined from a total evaporation experiment in which the ion beam was measured from the beginning to the end of the emission. With integration of the peak intensities, the fractionation effects can be minimised, since total evaporation of the reservoir cancels out the effect of vapour enrichment in the light isotopes. This experiment avoids the gravimetric uncertainty inherent in the double spike calibration. This calibration allows the precise redetermination of the seawater isotopic composition of Ca. A mean ⁴⁰Ca/⁴⁴Ca ratio for two Atlantic water samples of 45.143 (2s_mean= 0.003) was found. The good reproducibility of the Ca isotope ratios in present seawater and the very strong isotopic homogeneity of Ca in the oceans illustrate the advantage of using seawater as the common standard, with the advantage of decreasing interlaboratory bias.  相似文献   

同位素测定样品中钙和锶的分离     

王雪英  刘凤香 《岩矿测试》1992,11(3):240-242

与样品中基体和Rb分离了的Ca和Sr,在0.08mol/L柠檬酸-1.5mol/L NH_4OH介质中流经Dowex50×8阳离子树脂柱,并用此溶液淋洗Ca,用4mol/L HCI洗脱Sr。收集的含Sr溶液用于同位素年龄测定,消除了质谱测定过程中Ca的干扰。  相似文献   

容量法连续测定磷矿石中钙锶镁   总被引：2，自引：0，他引：2  

邝冠群 《岩矿测试》1993,12(2):128-130

改进了用EDTA络合滴定Ca、Sr和Mg的条件,建立了磷矿石中连续测定Ca、Sr和Mg的方法,用于实际样品测定,结果符合质量要求。  相似文献   

Phosphorus in Bottom Sediments of Pomeranian Bay (Southern Baltic—Poland)     

L. Frankowski  J. Bola ek  A. Szostek 《Estuarine, Coastal and Shelf Science》2002,54(6):1027

The paper presents the results of determination of inorganic and organic forms of phosphorus in bottom sediments of Pomeranian Bay. The sediments were collected in March and July of 1996. The following characteristics of the sediments were determined: organic matter content, forms of inorganic phosphorus: loosely adsorbed phosphorus and phosphorus bound to aluminium, calcium and iron, as well as total inorganic phosphorus. Pomeranian Bay is a shallow basin, with depth averaging between 12 and 15 m and sandy sediments prevailing. Smaller silt fractions occur only in the vicinity of the wina River estuary and in deeper northern regions of the Bay. Calcium-bound phosphorus is the dominant form of inorganic phosphorus in the Pomeranian Bay. Iron-bound phosphorus is the second most prevailing form, and aluminium-bound phosphorus the third. Loosely bound phosphorus was present in the lowest amounts. Total inorganic phosphorus in the Bay consisted of the four forms listed above, except in estuarine regions where an additional form of phosphorus occurred, most probably occluded phosphorus. High organic phosphorus concentrations were found at the wina River estuary and in the northern part of the Bay (Saßnitz Deep) corresponding to the higher organic matter content of these sediments. Sediments of Pomeranian Bay contained less phosphorus than those from the Gulf of Gda sk or Puck Bay and other parts of the Baltic Sea, suggesting that the amount of phosphorus in the sediments was determined by a number of inter-related factors, such as sediment type, amount of organic matter, the chemical composition of the sediment and oxygen content of near-bottom water.  相似文献   

羽毛复合氨基酸钙配合物降解有机磷农药的研究     

耿娟  汪东风  孙继鹏  苏琳  李雷 《中国海洋大学学报(自然科学版)》2006,36(Z1):71-74

有机磷农药在我国农作物生产中已被广泛应用,但常因使用不当造成作物产品中残留超标。采用硫酸水解羽毛制取复合氨基酸,并与碳酸钙反应制得复合氨基酸钙配合物,该配合物可以通过水解有机磷农药中的磷酸酯键降低作物中的农药残留。将配合物分别喷施已施有机磷农药的茶叶、黄瓜和西红柿,5d后采摘茶叶鲜叶,按绿茶加工工艺进行处理,测定其毒死蜱含量,毒死蜱的残留量减少了75.80%;喷施配合物次日采摘黄瓜和西红柿样品,并测定其毒死蜱与乐果的残留量,黄瓜中毒死蜱残留量为空白对照的70.75%,乐果完全降解;西红柿中毒死蜱残留量为空白对照的71.33%,乐果的残留量为67.79%。  相似文献