Problems with membrane filtration in brine purification
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With the new 50,000-ton capacity for chlor-alkali production, should ceramic membrane technology or organic membrane technology be used for brine purification? What are the current trends and directions for the refinement of brine? Is it related to the quality of industrial salt?
Currently, domestic ceramic membranes are mostly used. As salt manufacturers are also striving for cleaner production methods, they recover and make comprehensive use of calcium, magnesium, and sulfate ions present in salt. Therefore, chlor-alkali companies can now use either refined salt or refined brine, and ceramic membranes are sufficient for this purpose; moreover, the production process is greatly simplified as a result.
Crude salt is refined salt; there is no pre-treatment unit, and any type of filter can be used. Crude salt is unrefined salt, and in the absence of a pre-treatment unit, ceramic membranes are a better choice
The organic membrane process can fully achieve the elimination of pre-treatment units, and its energy consumption is much lower than that of ceramic membranes.
For ceramic membranes, the function is to remove calcium along with phosphates; however, resolving the phosphate issue is related to the quality of these membranes, and both TOC and iodine content must not exceed specified limits
Both types of membranes can eliminate the need for a preprocessor, but ceramic membranes have high energy consumption and high investment costs, and they are more complex compared to organic membranes.
Currently, organic membranes can handle various salt conditions, but ceramic membranes cannot; if the salt content is slightly high, the membrane tubes can get scratched and damaged. Moreover, ceramic membranes have high energy consumption and complex manufacturing processes, while the process using organic membranes without a pre-treatment unit is already quite mature. In China, such systems have been in use for over eight years now, with very stable saltwater quality, which can serve as a model for reference.
Membrane Engineering Research Institute of Hangzhou Research Institute, China National Coal Technology and Engineering Group; Manager Zhang: 18069869006. This institute is primarily engaged in the research and development as well as the promotion of specialized separation technologies using ceramic membranes. By leveraging its proprietary ceramic membrane technology, it serves industries such as food and pharmaceuticals, fine chemicals, the recycling of waste acids and alkalis, and the treatment of mining wastewater.
Without a pretreater for brine, the demand for the area and quantity of membranes increases significantly