China's economy is developing rapidly, and a large amount of energy consumption produces a large amount of industrial solid hazardous waste. Industrial solid hazardous waste mainly includes red mud, desulfurized gypsum, smelting slag, tailings sand and coal gangue. During the “Eleventh Five-Year Plan” period, the total production of hazardous wastes of industrial solids was 11.8 billion tons, and the total new stock was 19 billion tons. During the “Twelfth Five-Year Plan” period, the total production of hazardous wastes of industrial solids was 15 billion tons, and the total new stock was 27 billion tons. With the accelerating process of industrialization in China, these industrial solid hazardous wastes occupy a large amount of land and there is a danger of polluting the environment at any time.
At the same time, urban domestic wastewater, petrochemical, metallurgy, papermaking, fermenting, pharmaceutical, textile printing and dyeing wastewater are all organic wastewater. Organic wastewater is wastewater mainly composed of organic pollutants and contaminated by bacterial viruses. Organic wastewater is easy to cause eutrophication of water. The direct discharge of organic wastewater will cause serious pollution to the environment and pose a serious threat to human health. Therefore, organic wastewater must be treated effectively before it can be discharged. With the increase of the population of China, the acceleration of urbanization, the rapid development of industry and the continuous expansion of industrial scale, organic wastewater has a tendency to increase in quantity, concentration and toxicity.
Method for preparing calcium aluminate cement
by organic waste water and industrial solid hazardous waste:
The method is characterized in that a mixture of de-alkali red mud, calcium carbide slag, aluminum ash, desulfurized gypsum and a part of organic wastewater is mixed to obtain a mixed liquid. The moisture content in the mixed solution is 60% to 70% by mass. The mixture is further subjected to wet grinding, and then the wet-milled material is subjected to homogenization treatment to obtain a slurry. The slurry was dehydrated by mechanical pressure filtration to obtain a slurry. Another part of the organic wastewater is concentrated and then enters the rotary kiln together with the slurry for high-temperature calcination to obtain sulphoaluminate clinker. In the high-temperature calcination process, coal powder is injected into the rotary kiln to burn the organic waste in the coal powder, the slurry, and the organic waste in the concentrated wastewater.