China's environmentally friendly alumina production technology project won the highest honor in international inventions

From March 29 to April 2, 2017, the 45th Geneva International Invention Exhibition was held in Geneva, Switzerland. A total of nearly 1,000 invention achievements from 40 countries and regions participated in the exhibition. A total of 40 universities and colleges in China participated in the competition.

Among them, the team of Zhang Ting'an, Institute of Special Metallurgy and Process Engineering, Northeastern University's Institute of Metallurgy and Process Engineering researched and developed the “Calcification-Carbonization Treatment of Low-grade Bauxite Mines and Bayer Process Red Mud” project and won the highest honorable gold medal—the jury awarded a special gold medal.

In 2015, the China Non-Ferrous Metals Industry Association in Shenyang organized an expert team of Zhang Ting An, Northeastern University to complete the "large-scale low-cost and harmless treatment of Bayer process red mud technology" and "calcification-carbonation method to efficiently use low-grade bauxite ore "Clean production of alumina technology" was identified and it was agreed that both technical achievements have reached the international advanced level.

These two technical inventions not only theoretically eliminated the Bayer process's limitation on the production of alumina to bauxite aluminum-silicon grades, but also enabled the production of alumina using low-grade bauxite; furthermore, they achieved a significant reduction in sodium in red mud. The content of aluminum has fundamentally solved the large-scale, low-cost harmlessness and resource utilization of red mud, and is a subversive technology for alumina production.

The project of the team of Prof. Zhang Ting'an who participated in the exhibition “Calcification-carbonation process of low-grade bauxite and Bayer process red mud” overcomes the problems existing in Bayer's production of alumina technology and proposes zero-emission environmentally-friendly production oxidation. Aluminum new technology. The significant advantages of this technology are mainly reflected in three aspects:

First, the grade requirements for bauxite are greatly reduced. Bauxite with A/S (aluminum to silicon) ratio of less than 4 can be used; second, the alkali content of discharged red mud is less than 0.5%, and A/S is lower than 0.7. Third, red mud can be used as the main material of cement, or modified into soil, or as a fill soil in the mining area, to achieve zero emissions.

Compared with the existing Bayer process alumina production technology, this technology can save nearly 30% of the ore by using 1 million tons of alumina produced with the same sample ore, and can obtain more benefits of 300 yuan per ton of alumina, and more importantly, it can produce Harmless red mud has broken through the world's difficult problems of low-cost utilization of red mud.