钙芒硝岩盐溶解机理的实验研究

根据钙芒硝岩盐的结构特征,通过不同水溶时间下钙芒硝岩盐及其磨片的水溶实验,揭露了钙芒硝岩盐溶解过程中的温度-水流-力学-化学(T-H-M-C)耦合机理,论证了钙芒硝岩盐原位压力溶浸开采方法的合理性,提出了提高钙芒硝岩盐溶解速度的方法途径.     

水溶后钙芒硝空隙度的实验研究

水溶过程中矿石的空隙度是确定该矿床能否采用原地水溶开采方法开采的决定性因素.通过实验得出了钙芒硝在静态溶解情况下的空隙度,并认为对钙芒硝矿床的开采完全可以像其它易溶盐矿一样采用原地水溶开采方法.这对改进钙芒硝矿床开采方法、提高其开采效益、减少环境污染有很重要的意义.     

钙芒硝矿地质特征及矿床成因分析

芒硝在许多工业生产中作为一些化学物品的副产品产生,是一种在自然界中天然形成的一种矿产资源。芒硝矿主要包含芒硝、该芒硝和无水芒硝三种矿物质。据调查研究得知,在芒硝矿产资源中,占据比例最大的就是钙芒硝,约占全国芒硝资源总量的百分之九十左右。钙芒硝分布在我国的多个城市,其中以四川的钙芒硝分布含量最多。本文将围绕钙芒硝矿地质特征分析与该芒硝矿床的成因两个方面进行详细的分析和研究。     

钙芒硝矿全液相开采可行性的探讨

通过对钙芒硝的溶解度曲线、溶解时的热效应、钙芒硝与水的相平衡,以及经水采后的体积膨胀效应等的描述,认为实现钙芒硝全液相开采是可能的。     

盐穴储油库采卤管柱解堵工艺研究

岩盐与各种油品接触时不发生化学变化,不溶解,不影响油品的质量,因此盐穴作为地下储油库是一种理想的储油方法.在朱桥盐穴储油库实试验井东淮3井采卤建腔施工中随着采卤时间的延长采卤管柱出现堵塞,注入排量逐渐减少,井口压力逐渐增加,导致采卤周期延长,严重影响了盐穴储油库建腔施工的进展.对采卤管柱上附着的堵塞物进行实验室化验发现堵塞物的成分为钙芒硝,通过钙芒硝溶解实验优选了化学溶解药剂氢氧化钠,现场应用取得了较好的效果,证明了氢氧化钠对采卤管柱中的钙芒硝堵塞有较好的溶解作用,提出了解决盐穴储油气库采卤建腔过程中管柱堵塞的方法.     

碳酸铵浸出钙芒硝矿新工艺研究

针对钙芒硝矿传统水溶浸出过程会产生石膏钝化层的问题,采用碳酸铵对钙芒硝矿进行化学浸出。通过单因素试验考察了反应温度、反应时间、碳酸铵用量和液固比对钙芒硝矿浸出效果的影响,并利用正交试验得出了最优工艺条件,即反应温度60℃、反应时间50min、碳酸铵用量为理论用量的110%、液固比8∶1,此时钙芒硝矿的浸出率达到了93.6%。     

钙芒硝石膏深度提纯工艺的研究

钙芒硝石膏是工业上采用溶浸法生产元明粉的副产尾矿,与脱硫石膏和磷石膏等工业副产石膏相比其杂质含量高、纯度低、利用价值低。采用酸浸-重结晶工艺对钙芒硝石膏进行提纯,通过酸浸去除钙芒硝石膏中的酸溶性杂质,并将二水硫酸钙（DH）脱水转化为无水硫酸钙（AH）,然后控制水化条件,使AH水化为大尺寸的DH晶体,并与小尺寸的酸不溶性杂质分离开来,得到高纯度的二水石膏。研究了硫酸浓度、水化激发剂、液固质量比、反应时间等对石膏提纯的影响。研究结果表明：常压下,在硫酸酸洗液质量分数为35%、反应温度为80 ℃、石膏与硫酸溶液固液质量比为1∶5、酸洗时间为2 h时能有效去除钙芒硝石膏中的酸溶性杂质;在水化硫酸质量分数为5%、硫酸钾质量分数为1.74%、反应温度为25 ℃、固液质量比为1∶6、陈化时间为18 h时能有效去除钙芒硝石膏中酸不溶性杂质,提纯后的石膏纯度可达97%以上。     

钙芒硝尾矿的综合利用

目前钙芒硝(Na2SO4 ? CaSO4)矿被单一视为元明粉生产的原料,而与其伴生的芒硝石膏(CaSO4)通常作为尾矿抛弃而未得到有效利用,造成了资源浪费.为了利用芒硝石膏资源,在回顾总结现有副产石膏综合利用的多种途径的基础上,通过对比其优缺点,最终分析得出一种适合芒硝石膏综合利用的理想途径——制备建筑石膏(β半水石膏...     

金属铝的溶解性实验研究

金属铝在进行酸性溶解或碱性溶解时,通过搅拌、加热、加入适量的某种金属离子的盐溶液等措施可较大程度的提高金属铝的溶解能力。     

超声强化钙芒硝矿水溶浸出率的研究

提出了使用超声波技术提高钙芒硝矿水溶浸出率的设想,并对其机理进行初步探讨。通过实验,分析研究了钙芒硝矿在两种状态下的溶解特点,证实超声波在提高钙芒硝矿水溶浸出率方面具有显著的优越性。     

Dissolution characteristics of hectorite in inorganic acids

The effect of acid type (HCl, HNO₃ and H₂SO₄) and concentration on the dissolution rate of hectorite were monitored through chemical analyses and XRD. The rate of dissolution increased with increasing acid concentration during the first 2–4 h of contact. After that time, the correlation between acid concentration and the amounts of dissolved elements strongly decreased and often higher concentrations were found in 0.25 M solutions than in 1 M solutions. The monitoring of the amount of Si is somewhat more complex since it is the result of two processes: release from the mineral and reprecipitation as an amorphous end product. In the case of HCl, the behavior of Li, Mg and Fe differed from their behavior in the other acids, but further research is necessary to characterize the reactions that may occur. From the half times of dissolution, the dissolution curves and the XRD data, it could be concluded that the dissolution rate of hectorite decreased in the order H₂SO₄>HNO₃≥HCl at the same molar concentration, which is the reverse of what was found by other investigators. After 8 h, for example, the 1 M H₂SO₄ treatment dissolved more than 70% of all Li present in the hectorite, whereas equal molar HNO₃ and HCl dissolved 58% and 53%, respectively. Oriented XRD patterns only showed a background scatter after 6 h of contact with 0.25 M H₂SO₄ and after 4 h using a concentration of 1 M H₂SO₄. Treatments with 0.25 M HNO₃ and 0.25 M HCl still gave reflections after 6 h and even after 8 h, the d(001) XRD peak could still be observed. In 1 M HNO₃ and 1 M HCl, no more reflections could be seen after 4–6 h. At that time, XRD powder patterns showed that the crystal structure was still partly preserved in the a- and b-direction of the mineral. It must be stressed that absence or a decrease in intensity of the d(001) peaks may not be fully assigned to the breakdown of the mineral structure since the Si, extracted from the lattice reprecipitates as amorphous silica, which may disrupt the layer stacking and decrease the coherence of the reflections. For the comparison of the three acids on a normal basis, the quarter times of dissolution were found to be a more appropriate tool than the half times of dissolution. The results showed that the differences among the three acids were rather small and that the concentration of the acids was the main parameter affecting the dissolution rate of the hectorite, in particular, in the beginning of the treatment.     

Dissolution of phosphate rocks in soils. 1. Evaluation of extraction methods for the measurement of phosphate rock dissolution

The dissolution of phosphate rock (PR) in soil was determined by measuring the amount of either the dissolved inorganic phosphate (Pi) and Ca or the residual P and Ca remaining as undissolved PR in the soil. The dissolved Pi was extracted by either 0.5M NaOH or 0.5M NaHCO₃ and the dissolved Ca was extracted using either 0.5M BaCl₂/triethanolamine (TEA) or 1M NH₄OAc. Undissolved PR was extracted by 1M HCl following the extraction with either 0.5M NaOH or 0.5M BaCl₂/TEA.From the mixture of PR with dry soil, the 0.5M NaOH extracted between <0.1 and 4.7% of the undissolved Pi and the 0.5M BaCl₂/TEA extracted between 2.8 to 7.8% of the undissolved Ca. From PR incubated with moist soil, these reagents extracted most of the dissolved Pi or Ca (95 to 99%). The 0.5M NaHCO₃ extracted between < 0.1 to 4.8% of the undissolved Pi and the 1M NH₄OAc extracted between 5.2 to 10.5% of the undissolved Ca from the PR/dry soil mixture. However the extraction of dissolved Pi and Ca from PR incubated with moist soil by these reagents was incomplete (30 to 80%). The 0.5M NaHCO₃ and 1M NH₄OAc extractants tended to underestimate the extent of PR dissolution when the levels of dissolved Pi and Ca were high. The difference between the amounts of 0.5M NaOH extractable Pi (P) and 0.5M BaCl₂/TEA extractable Ca (Ca) in the PR-treated soil and in the soil alone gave a more accurate estimate of the extent of PR dissolution in laboratory incubated soils. However, under field conditions where the Pi and Ca released during the dissolution of PR can be removed by plant uptake and leaching, these two methods, which measure the amount of the dissolution products, may underestimate the extent of dissolution. Under these conditions, the amount of residual P or Ca extracted by 1M HCl is recommended as the best estimate of the amount of undissolved PR remaining in soil.     

原盐种类对氯碱生产的影响及应对措施

分析了西安西化氯碱化工有限责任公司所用工业原料盐的种类和特点,总结出应用不同盐种进行盐水精制的应对措施,有效保证了一次盐水的质量和电解装置的优越性能。     

疏水缔合聚合物在搅拌槽中的溶解特性

Enhanced oil recovery (EOR) by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China. Hydrophobically associating polyacrylamide (HAPAM) has been recently proposed as a new flooding agent. The solubility of HAPAM is low, which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield. Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving. But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks. In this paper, effects of temperature, salinity, stirring speed, impeller type and stirring method on the dissolution of HAPAM are reported. The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed, but the viscosity of the polymer solution decreases. There is an optimal range of salinity for polymer dissolving. Combining the operation mode of up-pumping with varying stirring speed, hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity.     

鹤峰磷矿在硫、磷混酸中的溶解动力学

对鹤峰磷矿在硫、磷混酸中的溶解动力学进行了研究,考查了硫酸质量分散及反应温度对酸解过程的影响;选用考虑了自阻化因素的德罗兹多夫方程In100/(100-Kp)-βKKp%=kt描述酸解过程的动力学.研究结果表明:鹤峰磷矿在硫、磷混酸中的反应速率常数随温度升高而增加,随硫酸质量分效的增加而减小.该反应属于扩散控制,平均反应活化能约为32.7kJ/mol.