类砂岩型矿石的浸出特性

来源期刊:中国有色金属学报2014年第7期

论文作者:吴爱祥 刘 超 尹升华 柯锦福 薛振林

文章页码:1856 - 1864

关键词:溶浸采矿;盐岩;动力学模型;浸出率

Key words:solution mining; salt rock; kinetic model; leaching rate

摘    要:根据配比试验,利用水泥、河砂、盐和水制作类砂岩型盐岩矿石试样,以水为浸出剂对不同品位试样进行浸矿特性试验,考察浸出液浓度随浸出时间的演变规律;讨论盐类浸出机理与其溶浸过程多相反应动力学;运用收缩核心模型和区域反应模型对浸出过程进行拟合,并分析浸出作用对试件强度及破坏形式的影响。结果表明:随着浸出时间的增加,整个浸出过程中浸出液浓度呈现由指数增长到线性增长、最后趋于稳定的3个阶段;盐类的浸出是一个溶解与结晶共同作用的过程,溶质的浓度差为浸出反应的根本动力;试件品位越高,其浸出液浓度变化曲线中的指数阶段越明显,线性阶段的斜率就越大;浸出率随时间同样表现出类似的3个阶段,但其品位越高,其最终浸出率反而越低;修正的收缩核心模型和区域反应模型可以用于拟合浸出液的浓度曲线;浸出后,试件的单轴抗压强度略有增加,但其破坏形式未发生变化,均为单斜面压-剪破坏。

Abstract: Based on the ratio test, the specimens for simulating sandstone type salt rock of different grades and consisting of cement, river sand, salt and water were made. The leaching experiment was carried out to explore the evolution rules of the concentration of the leaching solution. The leaching mechanism of salt and kinetics of the multi-phase reaction were analyzed. Shrinking core model and regional reaction model were used to fit the leaching process, and the effects of leaching on uniaxial compressive strength and its failure type were analyzed. The results show that, with the increase of leaching time, the concentration of the leaching solution goes through three stages: exponential growth phase, linear growth phase and stable phase. The leaching of salt is a procedure under the function of dissolution and crystallization, with concentration gradient of solute being the essential motivating force. The higher the grade of specimen, the more obvious the exponential growth phase, and the sharper the slope of the linear growth phase. The leaching rate also has the similar three phases as the concentration of the leaching solution, but the higher the grade, the lower the final leaching rate. The modified shrinking core model and regional reaction model can be used to fit the concentration curves of leaching solution. The uniaxial compressive strength (UCS) of the sample increases a little after leaching, however, the failure type of which does not change, and all of them are single bevel shear compression failure.

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号