With the deepening of China’s supply-side reform of electrolytic aluminium and the remarkable increase of alumina production capacity abroad, the era of high-profit alumina industry is expected to end without emerging countries replacing the decline in aluminium demand caused by China’s economic slowdown.
With the production process of alumina unchanged for decades, only the comprehensive utilization of red mud, known as a worldwide problem, is expected to carry the banner of the next profit outlet.
A Brief Introduction to Red Mud
Each ton of alumina produced about 1.5 tons of red mud, particle diameter 0.088-0.25 mm, specific gravity 2.7-2.9, bulk density 0.8-1.0, melting point 1200-1250 C. The composition of red mud is shown in the table below.
At present, Bayer process is widely used in the production of alumina in China. The red mud of Bayer process is characterized by high content of iron, aluminium and alkali.
Typical Cases of Red Mud Comprehensive Utilization in Alumina Enterprises
1. China Aluminum Shandong Branch: The available data are that the comprehensive utilization rate of red mud is 25% by 2016, and the total consumption of red mud is 12 million, which is the highest utilization rate of alumina enterprises in China at present. Henan Province Aluminum Industry Transition Development Action Plan (2018-2020) clearly put forward that the comprehensive utilization rate of red mud will reach 10% by 2020. There will be no harm if there is no contrast. The comprehensive utilization rate of red mud in China is too low. The main uses of red mud are to prepare new desulfurizer technology for coal combustion, high grade cement, highway roadbed, brick making and water purifying agent.
| Sulfamic acid 99.80% |
2. Weiqiao Group: In 2018, 20,000 tons of red mud were used on the 5.3 km Subgrade of Binzhou section of Jiqing Expressway. It is estimated that 200,000 red mud can be consumed per kilometer of highway, 60,000 tons of red mud can be consumed on Provincial Highway and 20,000 tons of red mud can be consumed on Municipal road. For countries with huge mileage of highway in China, the future market prospects are broad.
3. Typical Cases of Comprehensive Utilization of Red Mud by Social Forces
On December 31, 2018, Shandong Satellite Television broadcasted a news about the large-scale production of permeable bricks (70,000 tons of red mud per year) by Zibo Tianzhirun Ecological Technology Co., Ltd. The company’s red mud permeable brick project red mud blending rate as high as 90%, successfully selected in 2018 Shandong Province, ten innovative achievements of circular economy. The owner of the company invested more than 30 million yuan and finally gambled on the only two houses. Fortunately, the company succeeded. It is a worldwide problem to know.
| Sulfamic acid |
It is not only reminiscent that Inner Mongolia enterprises have spent tens of billions of dollars to break through the difficulty of producing alumina from fly ash, but there has been no breakthrough so far.
IV. Suggestions on Comprehensive Utilization of Red Mud
At present, red mud is used to produce cement, roadbed and permeable bricks, each of which has its own advantages and disadvantages. The production technology of cement is mature, but there are cement factories nearby and the consumption of roadbed is large. However, the future demand for highways in economically developed areas is limited. The production of permeable bricks can be popularized throughout the country. The disadvantage is that the sales radius is less than 800 kilometers.
Generally speaking, the comprehensive utilization rate of red mud in China is very low. Although the utilization rate of red mud in China is not worse than that in other countries, we can not compare with foreign countries in the future. The era of self-surpassing in China’s alumina industry has arrived. We have seized the profit outlet of red mud comprehensive utilization and will reshape the status of enterprises in the alumina industry.
| Magnesium Sulphate |