A few days ago, the key scientific and technological research project of Qinghai Province undertaken by the Institute of Process Engineering of the Chinese Academy of Sciences “Project for Producing High-Purity Magnesium Oxide by Sodium Carbonate from Salt Lake
Magnesium Chloride and ADC Foaming Agent” held a project acceptance and appraisal meeting in Xining City, Qinghai Province.
In the production process of potash fertilizer of the Qinghai Salt Lake Group, the old halogen after the potassium extraction was basically used as waste liquid (about 30 million tons of magnesium chloride), and was discharged into the salt lake through pipelines and channels, resulting in the local enrichment of magnesium salt; this not only caused waste of resources. And, to a certain extent, it has destroyed the resource structure of Salt Lake and affected the sustainable development and utilization of salt lake potassium resources. In addition, the Qinghai Salt Lake Group is building an annual production capacity of 1 million tons of ADC foaming agent production equipment in Qinghai. The process adopted is urea synthesis of hydrazine hydrate. This process produces a large amount of sodium carbonate, which is also not well digested locally. channel.
In October 2008, the project was supported by the Ministry of Science and Technology of Qinghai Province. From October last year to September of this year, Li Zhibao led the scientific research team to conduct the production of high-purity magnesium oxide by using sodium carbonate decahydrate, a by-product of brine magnesium chloride and ADC foaming agent, as a raw material to prepare crystalline magnesium trihydrate. Process route formulation. Under the optimal process parameters, the purity of trihydrate magnesium carbonate produced from brine magnesium chloride and sodium carbonate decahydrate was 99.5%. The purity of magnesium oxide produced from calcined trihydrate magnesium was 99.4%, and the recovery rate of magnesium was greater than 96% fully met the expected target. Using the salt lake magnesium chloride and ADC foaming agent by-product sodium carbonate as raw material, the economic value of producing 1 ton of high-purity magnesium oxide is about 4,000 yuan. After industrialization, the annual profit after tax is approximately 40 million yuan, which is calculated on the basis of an annual output of 10,000 tons of high-purity magnesium oxide. The process does not discharge any sewage, and the economic and social benefits are significant, and the high by-products are fully realized. Valued use. The project passed the mid-term assessment of the Science and Technology Department of Qinghai Province at the end of March 2009.
The Acceptance and Outcome Evaluation Expert Committee unanimously held that high-purity magnesium oxide prepared from the by-produced magnesium chloride of the potassium fertilizer and the by-product sodium carbonate of the ADC foaming agent is in line with the circular economy industrial policy and is of great significance to the comprehensive utilization of salt lake resources; the project is completed The contents and technical specifications stipulated in the contract have reached the leading level in China.
