【作者】 陈红燕；

【导师】 雷明光；

【作者基本信息】 四川大学 ， 化工过程机械， 2004， 硕士

【摘要】 本文在传统的湿法磷酸生产中磷酸料浆混合过滤的基础上,提出了分层过滤的新工艺。该工艺为提高湿法磷酸料浆过滤性能,促进磷酸生产的发展具有极大的作用。本文介绍了湿法磷酸生产中磷酸料浆的分层过滤实验。根据固液分离的基本原理,将磷酸料浆经过水力旋流器分级和分股,再将分级和分股后的轻、重液,通过分层延时加料形成分层过滤。过滤实验的装置则是采用真空泵和真空布氏漏斗。过滤实验所用料浆是根据不同的浓度进行配置的。采取正交试验,对影响磷酸料浆分层过滤性能的主要因素进行了实验研究。实验考虑的因素包括:过滤真空度、过滤温度、磷酸料浆浓度、分层加料延缓时间、轻液中的固相平均粒径。本文实验结果为:与传统的混合过滤相比较,该新工艺可显著提高磷酸料浆的过滤强度达14%～17%;在分层过滤新工艺中,影响磷酸料浆过滤性能的主要因素是过滤真空度、过滤温度、料浆浓度和轻液中固相平均粒径,其次是分层加料延缓时间;分层过滤的优化操作条件是:过滤真空度宜控制在65KPa左右,过滤温度宜控制在68℃～80℃之间,料浆浓度宜控制在900g/L左右,轻液中固相平均粒径宜控制在8.31微米左右,分层加料延缓时间宜控制在6秒左右;对实验数据按最小二乘法回归拟合,建立了磷酸料浆过滤速度的经验数学模型。本实验结果可用于湿法磷酸生产中料浆过滤设计和操作的理论依据,可用<WP=5>于磷酸工业生产的放大和优化。更多还原

【Abstract】 Based on the mixed filtration of phosphoric acid slurry in the conventional manufacturing of wet-process phosphoric acid, a new stratified filtration process was advanced in this article. This would greatly improve the filterability of wet-process phosphoric acid slurry, and in turn play a significant role in promoting the production of phosphoric acid.The stratified filtration experiment on phosphoric acid slurry was introduced in the first section of this article. According to the fundamental principles of solid-liquid separation, the phosphoric acid slurry was separated by hydro-cyclone to form thin and thick slurries, which were stratified-filtered by stepwise feeding of slurries. A vacuum pump was employed for filtration.The slurries used for filtration were formulated in different concentrations of phosphoric acid. Using orthogonal tests, the primary factors, such as degree of vacuum applied, filtration temperature, concentration of phosphoric acid slurry, the delayed time of stepwise feeding, and average solid particle size in thin slurry, influencing the stratified filterability of phosphoric acid slurry were investigated. The experimental results show that: as compared with the conventional mixed filtration, this technology can remarkably enhance the filtration intensity of phosphoric acid slurry. During the stratified filtration, the vacuum degree of <WP=7>filtration, filtration temperature and slurry concentration are among the most important factors influencing the stratified filterability of phosphoric acid slurry, followed by the average solid particle size, and finally the stepwise delayed feeding time has a weak effect on the filtration strength. The optimal operation conditions for stratified filtration are indicated as follows: The degree of vacuum filtration should be controlled at about 65Kpa, the filtration temperature should lie between 68 and 80 oC, and the stepwise delayed feeding time should approximately be 6 seconds. The experimental data are regression-fitted using Least Square method to establish an empirical mathematical model for filtration rate of phosphoric acid slurry.These results can be functioned as the theoretical fundamentals for design and operation of slurry filtration in the manufacturing of wet-process phosphoric acid, and also can be applied in the amplification and optimization of industrial production of phosphoric acid.更多还原