Views: 6 Author: Site Editor Publish Time: 2021-12-23 Origin: Site
In the process of wet process phosphoric acid production, the filter cloth is easy to wear due to calcium sulfate crystallization, iron aluminum salt precipitation, small fluosilicate particles and so on. It makes the water with high phosphate solid content, which requires further flocculation and sedimentation, so it not only consumes flocculants, but also introduces new impurities. At the same time, the sedimentation equipment covers a large area and takes a long time, resulting in low phosphoric acid output and high refining cost.
Flat Ceramic membrane has the advantages of good chemical stability, acid and alkali resistance, high mechanical strength and narrow pore size distribution. It has been widely used in chemical industry, food, medicine, environmental protection and other industrial processes. The following two factors are mainly considered in the process of solid-liquid separation of acidic solution by ceramic membrane.
First, the separation performance of ceramic membrane, such as the recovery of titanate particles in sulfuric acid wastewater produced by titanium dioxide and the recovery of ZrO2 particles in hydrochloric acid solution, can prove that ceramic filtration membrane has a good separation effect on powder particles in acidic solution, and the retention rate of powder is more than 98%.
The second is the corrosion resistance of ceramic membrane, which is also the key to the industrial popularization and application of ceramic membrane. Generally, it is expressed by measuring the bending strength and mass loss rate of ceramic membrane support before and after acid corrosion. Nitric acid has low corrosion to ceramic membrane, but the corrosion time is relatively short. Therefore, when ceramic membrane is used in phosphoric acid purification process, the long-term stability of ceramic membrane in phosphoric acid solution, the influence of operating conditions on membrane separation performance and the control effect of recoil on membrane pollution are obvious.
Ceramic membrane has the characteristics of good chemical stability, acid, alkali and organic solvent resistance, high mechanical strength, backwashing, strong anti microbial ability, high temperature resistance, narrow pore size distribution and high separation efficiency. It has been widely used in food industry, bioengineering, environmental engineering, chemical industry, petrochemical industry, metallurgical industry and other fields.