Current situation of alumina industry technology

As far as the current alumina industry in China is concerned, in terms of technology, except that a few enterprises such as Aluminum Corporation of China retain the sintering process to a little extent, China's alumina enterprises basically adopt the Bayer process, and most of which adopt the technical mode of Guangxi Pingguo.

In terms of product quality, 90% of the output of alumina is used in electrolytic aluminum industry, and sandy alumina has become the raw material of modern electrolytic aluminum industry in the world. In order to realize environmental protection and energy conservation, the world's modern electrolytic aluminum industry has developed the dry flue gas purification technology and the technology of large intermediate point blanking prebaked anode electrolyzer. These technologies require the use of high-quality metallurgical grade sandy alumina. Sandy alumina has coarse and uniform particle size, so that it can reduce the flying loss of alumina dust; has good fluidity and high strength, so that it can reduce crushing during transportation; has a large specific surface area, so that the solubility in electrolyte can be improved, and hydrogen fluoride gas in dry purification system can be absorbed. Therefore, it has become an ideal raw material for electrolytic aluminum plants at home and abroad.

In terms of the broad concept of quality, quality includes quality and quantity. From the perspective of quality, the physical and chemical indicators vary widely; from the perspective of quantity, the decomposition rate or cycle efficiency is also uneven, all of which are not at the same level as the indicators of Pingguo mode, and still show a certain gap in energy conservation, consumption reduction, production and quality improvement. At present, the popular alumina decomposition additives in the market include imported products and domestic products. Their appearance is oil or emulsion, and their function is mainly to coarsen the particle size of aluminum hydroxide products in the decomposition process of sodium aluminate solution, but they do not promote the decomposition rate, and even some products reduce the decomposition rate. Oil or emulsion additives have poor dispersion performance, and they also increase the content of organic matter in the solution. In response to this situation, the scientific and technological personnel of Shiyuan Company developed a water-based alumina decomposition aid, which avoided the above shortcomings and achieved good results.

At present, some prominent problems in the production technology of alumina enterprises are as follows:

I. Unbalanced matching of production process parameters;
II. High organic content;

III. High content of sodium, sulfur and iron in products;

IV. High energy consumption caused by scarring;

V. Low decomposition rate and circulation efficiency;

VI. Unstable product granularity, showing periodic changes between coarsening and refinement;

VII. Poor product strength and high damage rate;

VIII. Reverse relationship between yield and quality.

For the above one to four problems, our company has the corresponding technology to provide solutions; for the above five to eight problems, our company has invented a new decomposition and crystallization additive Xanadu21, which has achieved the following results in the practical application of an alumina enterprise in China, completely surpassing other similar products.

Effect of Auxiliary Agent in Xanadu21 Alumina Production and Decomposition System of Shiyuan Company

1. Break the traditional contradiction between quality and output, and simultaneously improve quality and output (generally, the decomposition rate can be increased by about 2.5% on average. In an industrial trial of an alumina enterprise in Guangxi, the decomposition rate is higher than that of other countries.Compared with the decomposition rate of a decomposition aid, the decomposition rate of a company in Shanxi increased by 3.51%; the decomposition rate of a company in Shanxi increased by 5.71%, and the coarsening of product particle size fluctuated smoothly. ).

2. It breaks the law of periodic coarsening and refinement of the system product granularity, which can keep the system product granularity stable;

3. The microstructure of the product is improved, the strength is increased, and sandy alumina can be produced;

Fourth, reduce the amount of organic matter entering the same product, and reduce the impact of organic matter in the system on the decomposition process.

5. For the crystallization of sodium oxalate in solution, there is adetermined role.

From the perspective of laboratory verification research and industrial use case exchanges, the effect of the second-generation products is more prominent.

From an economic point of view, it is calculated based on an average increase of 2.5% in the production capacity of 1 million tons of alumina and the decomposition rate of the enterprise:

The alumina output can be increased by 49,000 tons per year. According to the alumina price of 2,700 yuan / ton on April 18, 2019, the output value can be increased by 132.3 million yuan / year, which achieves the effect of increasing income and reducing fixed cost ratio (can offset purchases decomposition aid cost).