离子型稀土矿原地浸矿开采对地下水环境影响数值模拟

以某离子型稀土矿为例,通过对矿体赋存特征和采矿工艺的分析,建立数学模型,对浸矿液在地下水中运移规律进行模拟.根据模拟预测结果提出地下水污染防治措施,再对采取措施后地下水中污染物分布规律进行模拟.模拟结果表明:截渗措施能有效防止原地浸矿开采对地下水环境的污染.     

硫化锌精矿加压酸浸渣回收工艺及其环境影响分析

以硫化锌精矿加压酸浸渣为研究对象,系统的分析了加压酸浸渣浮选回收硫精矿,浮选尾矿经两段浸出、氧化除铁、锌粉置换和蒸发浓缩等工序回收七水硫酸锌的工艺过程,并分析了该过程产生的废气、废水、废渣和噪声等对周围环境的影响。     

FeS2-MnO2-H2SO4浸出软锰矿反应

针对FeS2-MnO2-H2SO4浸出软锰矿的浸出过程进行了研究,考察了反应过程中FeS2反应方式对MnO2浸出的影响.研究过程中分别对矿浆中的Mn2+,Fe2+和Fe3+质量浓度,以及矿浆电位的变化进行了监测,并对浸出过程进行了阶段的划分与分析.通过对浸出过程中不同反应阶段的分析,发现不同反应阶段过程中Mn2+与Fe3+浸出速率的比值是不同的,说明在不同阶段存在着不同的反应方式,导致FeS2的利用率在不同阶段存在明显差异.同时,对矿浆电位的监测表明,高电位有利于FeS2浸出Fe2+,从而加快了MnO2的浸出速率.     

钒渣钙化焙烧的影响因素及焙烧氧化动力学

采用钙化焙烧方式处理转炉钒渣以提高钒的浸出率,考察了焙烧参数(渣样粒度,升温速率,焙烧保温温度及保温时间,配钙量)对钒浸出率的影响,根据钒渣氧化的TG-DSC曲线对钒渣氧化变温动力学进行了分析.结果表明:降低升温速率可提高钒氧化率,保温温度高于600℃时钒浸出率迅速增加.在钒渣粒径48~75μm,外配钙m(CaO)/m(V2O5)为042,升温速率2℃·min-1,保温温度850℃,保温时间150min的条件下,钒浸出率达9331%.钒尖晶石氧化过程受三级化学反应控制,升温速率为5和10℃·min-1的表观活化能分别为26765,25603kJ·mol-1.     

基于图像处理的矿石颗粒三维微观孔隙结构演化

采用高精度显微CT技术及三维图像分析方法研究氧化铜矿石颗粒在酸浸前后内部微观孔隙结构特征及其演变,考察孔隙率、孔隙尺寸分布、孔隙连通度、孔隙分维等参数的变化规律。结果表明：酸浸后矿石颗粒的孔隙率明显增加,孔隙尺寸分布范围更广,出现一定比例的大孔隙,平均孔隙直径增加2~3倍;孔隙连通度在酸浸前基本为零,酸浸后明显增加,并在各方向上呈现空间变异性;孔隙分维数在浸出结束后也有所增大,且在一定范围内与孔隙率及平均孔隙直径呈指数增长关系。借助三维图像分析可实现矿石浸出过程中内部微观孔隙结构的定量描述,从而揭示矿石颗粒孔隙结构的演化规律。     

Leaching of vanadium,sodium, and silicon from molten V-Ti-bearing slag obtained from low-grade vanadium-bearing titanomagnetite

The water leaching process of vanadium, sodium, and silicon from molten vanadium-titanium-bearing (V-Ti-bearing) slag obtained from low-grade vanadium-bearing titanomagnetite was investigated systematically. The results show that calcium titanate, sodium aluminosilicate, sodium oxide, silicon dioxide and sodium vanadate are the major components of the molten V-Ti-bearing slag. The experimental results indicate that the liquid-solid (L/S) mass ratio significantly affects the leaching process because of the respective solubilities and diffusion rates of the components. A total of 83.8% of vanadium, 72.8% of sodium, and 16.1% of silicon can be leached out via a triple counter-current leaching process under the optimal conditions of a particle size below 0.074 mm, a temperature of 90°C, a leaching time of 20 min, an L/S mass ratio of 4:1, and a stirring speed of 300 r/min. The kinetics of vanadium leaching is well described by an internal diffusion-controlled model and the apparent activation energy is 11.1 kJ/mol. The leaching mechanism of vanadium was also analyzed.     

用复合浸出剂浸取风化壳淋积型稀土矿中的稀土研究

研究了采用新型复合浸出剂来浸取风化壳淋积型稀土矿中的稀土,结果表明：新型复合浸出剂浸取稀土浸出率高于单一浸取剂,能减少某些非稀土杂质元素的浸出,浸取后的浸出剂经提纯后能反复使用,而且这种新的稀土浸出剂具有来源广、价格便宜、不污染环境等优点,有推广应用价值。     

离子型稀土原地浸析采矿室内模拟试验研究

叙述了离子型稀土矿用原地浸析采矿开采时进行室内模拟浸析试验的原矿样采集与加工、试验装置、试验内容．论述和分析了试验情况．得出了对该类矿山的原地浸析开采设计有重要参考价值的试验参数     

Ultrasound effects on zinc recovery from EAF dust by sulfuric acid leaching

In this work, an ultrasound-assisted leaching process was studied for the recovery of zinc from electric arc furnace (EAF) dust, in which zinc was mainly present in the form of franklinite (60%). Hydrometallurgy is emerging as a preferred process for the recovery of a variety of metals, and the use of ultrasound could offer advantages over the conventional leaching process, especially for the dissolution of franklinite. Franklinite is a refractory phase that is difficult to leach and represents the main obstacle in conventional hydrometallurgy processing. Atmospheric leaching with different sulfuric acid concentrations (0.2-2.0 M) at two temperatures (323 and 353 K) was performed. The tests were conducted using both conventional and ultrasound-assisted leaching. After the leaching tests, the solid residues were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, whereas the leach liquor was analyzed by inductively coupled plasma spectroscopy (ICP). The use of ultrasound facilitated the dissolution of franklinite at low acid concentrations and resulted in a greater zinc recovery under all of the investigated operating conditions.     

Extraction of vanadium from vanadium slag by high pressure oxidative acid leaching

To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vanadium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L-1, a leaching temperature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10:1 mL·g-1, and oxygen pressure at 0.2 MPa, the leaching rate of vanadium reaches 97.69%.