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31.
方解石与硅灰石常相互伴生,因矿物晶格中都含有Ca2+而具有一些相似的表面性质和溶解特性;但是,两种矿物所含阴离子基团的不同,又使它们在浮选中表现出一定的差异性。本文以方解石和硅灰石为研究对象,分别研究了十二胺和油酸钠对方解石和硅灰石浮选行为的影响;通过Zeta电位分析和logC-pH分析,研究了不同pH值条件下方解石和硅灰石的表面荷电情况以及溶液中的优势组分情况;通过XPS测试和MS模拟,研究了方解石和硅灰石表面Ca质点密度和Ca不饱和键密度的情况。Zeta电位分析和logC-pH分析的结果表明,由于定位离子的不同,方解石比硅灰石带有更多的表面净剩正电荷;XPS和MS模拟的研究结果则表明,方解石比硅灰石具有更多的表面Ca质点密度和Ca不饱和键密度。 相似文献
32.
33.
济阳坳陷早古生代方解石脉成因分析 总被引:1,自引:0,他引:1
利用电子探针微区定量分析、碳氧同位素质谱分析和岩石包裹体分析3种方法,分析了济阳坳陷早古生代碳酸盐岩脉体形成的原因。利用方解石脉体的化学组分特征和碳氧同位素组分特征判断了其形成的原始环境,通过脉体包裹体特征判别方解石脉形成的温度以及形成的期次。研究表明,济阳坳陷下古生界方解石脉体成因主要以热液沉积为主,其次还受到地表渗入水的影响。 相似文献
34.
Mansoor Alam Tarasankar DebRoy Rustum Roy 《Journal of the American Ceramic Society》1990,73(3):733-735
High-pressure phases of CaCO3 , namely aragonite, calcite II, and possibly calcite III, were synthesized in air by exposing 10- to 20-μm-size particles of CaCO3 (calcite I phase) to a CO2 laser radiation at short pulse lengths (≤0.1 ms). The process, therefore, has the same effect as exposing the particles to at least several hundred megapascals pressure. Processing at higher pulse lengths resulted in the decomposition of CaCO3 to CaO and CO2 . The extent of decomposition increased with increasing pulse length. 相似文献
35.
The variation of hardness of rhombohedral single crystals of calcite and sodium nitrate with quenching temperature is studied.
Vickers and Knoop hardness numbers are determined from the indentations produced on freshly-cleaved crystal surfaces for various
loads. The variation of hardness number with quenching temperature can be represented byHT
q
k
=constant where the exponentk is less than unity and its sign determines the nature of material. 相似文献
36.
SHALLOW-MARINE MICROPOROUS CARBONATE RESERVOIR ROCKS IN THE MIDDLE EAST: RELATIONSHIP WITH SEAWATER Mg/Ca RATIO AND EUSTATIC SEA LEVEL 总被引:1,自引:0,他引:1
The formation of shallow-marine microporous carbonate reservoir rocks remains poorly understood in spite of their economic importance, particularly in the Middle East. In this paper, we investigate relationships between the stratigraphic occurrence of these carbonates in the Middle East and (i) the evolution of the Mg/Ca ratio in seawater; and (ii) cyclic variations in relative sea-level.
An inventory of carbonate formations in the Middle East was compiled for three geological time intervals characterised by different seawater chemistries: the Late Carboniferous to Triassic (aragonite seas); the Cretaceous (calcite seas); and the Cenozoic (transitional from calcite to aragonite seas). For each time interval, carbonate formations described as microporous have been listed.
During the Cretaceous calcite sea, eleven microporous carbonate formations were deposited in the Middle East. However, no microporous carbonates were formed during the Late Carboniferous to Triassic, a time of aragonite seas. During the Cenozoic, four of the five microporous carbonate formations recorded were deposited before the transition from calcite to aragonite seas. Thus, these shallow-marine microporous carbonates appear to have developed from precursor muds which were mainly composed of low-Mg calcite crystals. Moreover, during the Cretaceous and the Cenozoic, microporous carbonate formations in the Middle East were generally associated with major transgressions and highstands of relative sea level.
The relatively high stability of low-Mg calcite muds may explain why shallow-marine microporous carbonates formed during time intervals with calcite seas. In contrast to muds composed of aragonite or high-Mg calcite crystals, the original microfabric (including intercrystalline microporosity) of low-Mg calcite muds can partly survive moderate diagenesis. 相似文献
An inventory of carbonate formations in the Middle East was compiled for three geological time intervals characterised by different seawater chemistries: the Late Carboniferous to Triassic (aragonite seas); the Cretaceous (calcite seas); and the Cenozoic (transitional from calcite to aragonite seas). For each time interval, carbonate formations described as microporous have been listed.
During the Cretaceous calcite sea, eleven microporous carbonate formations were deposited in the Middle East. However, no microporous carbonates were formed during the Late Carboniferous to Triassic, a time of aragonite seas. During the Cenozoic, four of the five microporous carbonate formations recorded were deposited before the transition from calcite to aragonite seas. Thus, these shallow-marine microporous carbonates appear to have developed from precursor muds which were mainly composed of low-Mg calcite crystals. Moreover, during the Cretaceous and the Cenozoic, microporous carbonate formations in the Middle East were generally associated with major transgressions and highstands of relative sea level.
The relatively high stability of low-Mg calcite muds may explain why shallow-marine microporous carbonates formed during time intervals with calcite seas. In contrast to muds composed of aragonite or high-Mg calcite crystals, the original microfabric (including intercrystalline microporosity) of low-Mg calcite muds can partly survive moderate diagenesis. 相似文献
37.
38.
Thiyagarajan Subramanian Ankit Sonthalia 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2019,41(16):1972-1982
The present study aims to reduce carbon dioxide (CO2) emission from a CI engine using calcite/activated carbon-based post-combustion CO2 capture system fueled with Calophyllum inophyllum biodiesel (B100). The tests were conducted in a two-cylinder CI engine used in tractors at different load conditions. The performance and emission parameters of diesel and B100 with and without calcite and activated carbon-based CO2 capture system were studied. The results show that compared to diesel, CO2 emission increased by 19% for B100 due to high fuel-bound oxygen and carbon. Higher NO emission with a slightly reduced smoke opacity is observed with B100 combustion. CO2 emission is reduced with the CO2 capture system for both diesel and B100. CO2 emission is reduced by 11.5% and 7.3% for diesel with calcite and activated carbon, respectively, and reduced by 15.8% and 10.5% for B100 with calcite and activated carbon. Due to the adsorption capacity of both calcite and activated carbon, NO and smoke opacity are reduced considerably. The results display that calcite is better in reducing CO2 compared to activated carbon-based CO2 capture system. It is perceived that the combination of biofuel and calcite-based CO2 capture system can both reduce engine-out emissions and cause a net negative CO2 emission as it is renewable aiding in mitigation of global warming effects. 相似文献
39.
滕建彬 《油气地质与采收率》2020,27(2):18-25
为明确东营凹陷页岩中方解石矿物成因和储层成岩特征,利用薄片、X衍射、碳氧同位素等分析技术,首次发现了牛页1井页岩中方解石脉具有示顶底构造和机械双晶特征,是地质构造运动产生地应力作用于页岩方解石脉上留痕的直接岩石学证据,为页岩地层地应力的研究提供了载体矿物。通过对研究区页岩中泥晶方解石和亮晶方解石的碳氧同位素对比分析发现:页岩中泥晶方解石的形成主要隶属于与甲烷细菌活动生成生物气有关的碳酸盐,亮晶方解石脉极可能为泥晶方解石溶蚀后再沉淀重结晶的产物。生烃增压等作用形成微裂缝是方解石脉形成的先决条件,有机酸对泥晶方解石的溶蚀和再沉淀是必要条件。根据发现的4个岩石学特征和碳氧同位素证据,阐述了从生烃增压、微裂缝形成、有机质热演化排出有机酸、泥晶方解石被溶蚀、方解石重结晶,直至方解石脉形成的整个同生演化过程,并探讨了页岩与相邻砂岩的碳库来源和砂泥岩协同成岩演化过程。 相似文献
40.
为了寻找砂土中微生物诱导碳酸钙结晶(MICP)过程的无损检测方法,采用3种粒径的砂子和两种浓度的胶结溶液进行了砂土的胶结试验,检测了砂土流出液的流量、p H值、尿素浓度和Ca2+浓度等化学指标变化情况,并对碳酸钙晶体的生成数量和分布进行了分析。试验结果显示:砂土流出液的流量和Ca2+浓度能够预测MICP过程中碳酸钙晶体的生成数量,p H值和尿素浓度能够预测MICP过程中尿素的水解程度;砂土中碳酸钙晶体的生成数量与注入的Ca2+总量呈现线性增长的关系,其线性系数可以通过砂土的粒径和胶结溶液的浓度表示,胶结后砂柱的碳酸钙分布并不均匀,小粒径的砂柱上部碳酸钙含量较高,而大粒径的砂柱下部碳酸钙含量较高。 相似文献