化学腐蚀下灰岩力学效应的试验研究

结合三轴压缩试验结果，详细分析了不同化学溶液作用下，化学腐蚀对灰岩全应力．应变过程曲线各阶段的影响特征，并对化学溶液的腐蚀影响机理进行分析，获得了不同化学溶液对灰岩变形及强度腐蚀效应的影响规律。     

龙门山石灰石矿排土场的选择与应用

根据矿山原排土场的遗址原则，对已定排土场与新选排土场的位置特点进行分析蕊综合比较，指出新选排土场最佳，杨凹排土场其次．内部排土场在时间和启用方式适当时可予启用，而云中寺，茅子山2#和3#排土场的选址不恰当．建议不予利用。     

浙江石灰石脱硫性能的评价分析

本文对石灰石脱硫工艺应用现状进行了简要的阐述,设计石灰石脱硫性能评价装置并且建立了评价方法,研究浙江主要石灰石的脱硫性能,分析了石灰石脱硫活性与石灰石结构的关系,对浙江主要石灰石作为脱硫剂进行初步评价。     

10710工作面灰岩探查孔出现问题分析

针对10710工作面机巷施工灰岩探查孔过程中出现的问题,从底板岩层应力分布状态方面分析,寻找钻孔变形的原因,提出防治措施,避免类似事故发生。     

Limestone Drain Design Parameters for Acid Rock Drainage Mitigation

Abstract.  Limestone drains are an integral component of some of the most efficacious passive systems for the treatment of acid rock drainage (ARD). A critical design parameter for a limestone drain is the mass of limestone that will be required for effective treatment. This in turn depends on the flow rate, limestone dissolution rate, and associated hydraulic detention time necessary to achieve a certain effluent alkalinity for a given design life. Rates of alkalinity generation and limestone dissolution, and the quality of the limestone in terms of weight fraction of CaCO₃ and percentage CaCO₃ available must be known to determine the required mass of limestone. These parameters were experimentally determined for a natural and synthetic suite of ARD waters. The experimental results show that the empirical change in the alkalinity over time cannot simply be modeled as a first-order process. During the initial stage, the concentration increase is extremely fast, giving a linear and steep rise in the alkalinity. Alkalinity concentrations peaked at elapsed times of 90 to 180 minutes and then declined to a nearly constant value. The decline in alkalinity corresponds with a decline in concentrations of dissolved iron and aluminum, implying that the consumption of alkalinity by the hydrolysis of these metals is faster than the rate of alkalinity production by the dissolution of limestone, so that the reaction appears zero order in the early stage and pseudo-first order later. Because the changes in concentration were complex, considerable uncertainty exists in the rate constants for estimating alkalinity concentration. This causes problems in design equations based solely on a limestone dissolution rate that is estimated from alkalinity generation rates. A more applicable design procedure, combining the kinetics of alkalinity production and consumption with the hydraulics and chemical equilibrium of the system, is illustrated. Research was conducted while the first and third authors were with Ecology and Environment, Inc, Dallas, TX, USA;     

Prospects of utilization of waste dumped low-grade limestone for iron making: A case study

Low grade dumped limestone sample having high silica of 8.1%, 36.8% CaO, and 3% Al_2O_3 has been studied with the aim to reduce the silica level to below 3% for its utilization in iron making. Beneficiation study of the sample was initiated with desliming of the feed sample of -100 μm to remove the siliceous ultrafine particles and to improve the feed quality. Flotation study was carried out by column flotation technique varying the collector dosage, superficial air flow velocity and froth depth to assess their effect on silica reduction and CaO recovery. It was observed that increased collector dosage and superficial air velocity increases the recovery of CaO, and increase in the froth depth reduces the mass flow and silica content in the concentrate. The best result was found at 1.25 cm/sec superficial air velocity, 25 cm froth depth, 1.25 kgpt collector dosage and concentrate assayed 47.3% CaO, 2.8% silica with 72% CaO recovery.     

凝灰岩型隧道洞砟机制砂混凝土和易性与力学性能研究

利用杭绍台高速公路隧道洞砟,制备凝灰岩型机制砂,分析了机制砂及石粉特性,研究其对砂浆、混凝土流动性与强度的影响,利用条形筛检测机制砂中片状颗粒,探究不同片状颗粒含量对砂浆与混凝土和易性的影响规律,并研究不同砂率对C30与C35混凝土性能的影响。试验结果表明:凝灰岩型机制砂为硅质机制砂,表面的断键导致石粉易团聚,对亚甲蓝值不敏感,需水量大。随着石粉与片状颗粒含量的增加,砂浆与混凝土的流动性与强度不断降低。凝灰岩片状颗粒含量大于石灰岩片状颗粒含量对强度的影响程度,片状颗粒含量对低水胶比砂浆流动性及强度影响幅度大于高水胶比影响幅度。考虑混凝土的工作性和抗压强度,机制砂中石粉含量宜小于8%,片状颗粒含量宜小于10%,选定C30的砂率为43%,C35的砂率为41%。     

中东×区生物碎屑灰岩储集空间测井表征方法

中东×区H油田发育孔隙型生物碎屑灰岩,储集空间复杂,发育有粒间孔、生物体腔孔等原生孔隙和溶蚀孔、铸模孔等次生孔隙,次生孔隙发育情况与储层产能、渗流性能等密切相关。结合岩心及测井资料建立储集空间类型识别方法,采用高斯函数拟合成像测井孔隙度谱,得到原生和次生孔隙的截止值及占比;分析三孔隙度测井和核磁共振测井响应与原生和次生孔隙占比的关系,建立了次生孔隙占比的测井计算模型。研究表明,结合储集空间类型确定成像测井孔隙度谱原生和次生孔隙截止值及占比,用于常规测井刻度,建立常规测井计算次生孔隙占比方法,2种方法计算结果相近,表明所建方法表征生物碎屑灰岩储集空间的有效性,为储集空间的定量表征提供了新思路。     

不同孔隙类型礁灰岩模型微观水驱渗流实验

为了更好地了解礁灰岩储层中的流体在微观渗流过程中的渗流规律和分布特征,文中以流花油田D5P1井为例,利用礁灰岩岩心制作了岩心薄片模型,采用可视化技术微观模拟水驱油过程,并选取具有代表性的4种孔隙类型进行对比分析研究。实验观察发现,裂缝方向与微观流体渗流和剩余油的分布密切相关,孔洞的存在有利于提高岩心采收率,在驱替结束时基质中普遍存在大量的剩余油。这些发现为该油田下一步进行注水开发提供了参考依据。