三水碳酸镁浆液过滤及脱水性能的测定与模拟

doi:10.12034/j.issn.1009-606X.217142

摘要/Abstract

摘要： 考察了颗粒特征(尺寸和形状)和操作条件(过滤差压、离子强度、浆液固体浓度和过滤温度)对三水碳酸镁沉降、过滤和脱水性能的影响. 结果表明，三水碳酸镁的沉降速率受离子强度和浆液固体浓度影响明显，过滤性能与离子强度无关，提高浆液固体浓度和过滤温度、增加颗粒尺寸和降低过滤差压大均有利于改善三水碳酸镁的过滤性能；三水碳酸镁脱水性能的提高有赖于高的过滤差压和高的浆料浓度. 基于实验数据，通过回归计算得到三水碳酸镁滤饼的压缩系数和孔隙分布因子，采用Happel模型以三水碳酸镁的颗粒尺寸、滤饼的平均孔隙率及其它颗粒特征数据对三水碳酸镁滤饼比阻进行模拟计算，结果与实验数据一致性高，表明该模型可用于三水碳酸镁滤饼比阻的预测.

关键词: 三水碳酸镁, 过滤, 脱水, 沉降, 滤饼比阻

Abstract: The effect of particle characteristics (i.e. particle size and shape), as well as operating conditions (i.e. pressure drop, ionic strength, solid concentration in slurry and filtration temperature) on the settling, filtration and dewatering properties of nesquehonite were investigated. The results showed that the settling rate was strongly dependent on ionic strength and solid concentration. Meanwhile, the filterability, independent of ionic strength, was improved under the conditions of high solid concentration and filtration temperature, low vacuum pressure drop and large crystal size of nesquehonite. Increased dewaterability was revealed at high vacuum pressure drop and solid concentration. Besides, compressibility coefficient and pore size distribution index of nesquehonite cake were determined by further modeling work. Finally, Happel model was used to predict the specific cake resistance with the particle size, average cake porosity and other particle characteristic data of nesquehonite, and the calculated values were in good agreement with experimental data.

Key words: nesquehonite, filtration, dewatering, settling, specific cake resistance

王道广李志宝王英军. 三水碳酸镁浆液过滤及脱水性能的测定与模拟[J]. 过程工程学报, 2017, 17(6): 1217-1226.

Daoguang WANG Zhibao LI Yingjun WANG. Filtration and Dewatering Characteristics of Nesquehonite Suspensions: Experimental and Modeling[J]. Chin. J. Process Eng., 2017, 17(6): 1217-1226.

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