You can also burn clinker without limestone

Xinjiang Shihezi Shisanzi Shihmen Cement Factory adopted the Tianfu Thermal Power Plant fly ash, Nanshan coal gangue and sugar plant sugar mud as the additive materials, and in May 2003, it passed repeated demonstrations and trials. Invested more than 2 million yuan to build a horizontal energy-efficient rotary drying furnace with 2.4mx18m diameter, and dried the PVC residue (carbohydrate slag) of Shihezi Zhongfa Chemical Co., Ltd. of Tianye Group, which will have a water content of 40%. Down to about 2%, the cement used to replace limestone has been successful, and has received significant economic and social benefits.
In 2002, the Shihong Cement Plant was transformed into a technological transformation and expansion, and the annual cement output increased from 30,000 tons to 200,000 tons. The output has increased, and the consumption of limestone has increased significantly. In Shihezi where resources are relatively poor, limestone reserves have been decreasing. Therefore, how to make rational use of limestone mineral resources, protect the ecological environment, and develop new raw materials to replace limestone are more practical.
From the beginning of 2002, the engineering and technical personnel of the plant investigated and analyzed the “three wastes” of the surrounding factories and mining companies, and selected calcium carbide slag from Tianye. Its main component was CaO, and the content was stable at about 62%. Fully demonstrated that calcium carbide slag can be used as the main raw material for the production of cement (limestone). In order to remove 40% of the water content in calcium carbide slag and solve the influence of process recipes and calcining of cement clinker, the plant immediately established a task research team that combines professional technicians and workers to conduct in-depth discussions on relevant issues. Timely adjustments to process parameters, changes in recipes and methods of operation, and transformation of drying ovens were used. After repeated trials, they were finally successful in April 2003. At present, the Taiwan-based output of the dryer-baked carbide slag is increased from 3 tons to 6-7 tons, so that the amount of carbide slag added during the production of cement gradually increases, accounting for about 10% of the total input, instead of About 40% of the amount of limestone is used. At the same time, the output and quality of cement have increased to varying degrees. This factory took a new path from the application of calcium carbide slag to produce cement, and tasted the sweetness. A new dryer with a diameter of 2.4 meters by 18 meters has now entered the installation phase and is expected to be completed and put into use in July. At this time, the amount of calcium carbide slag will be about 20% to 30% of the total input, and it will even replace limestone completely.
The use of calcium carbide slag instead of limestone to produce cement not only saves the amount of non-renewable resources of limestone, satisfies the demand for raw materials for cement production, but also solves the problems that Tianye Group has been unable to deal with due to waste slag pollution for many years, making resources fully available. Reasonable use has improved the ecological environment. At the same time, Shihong Cement Factory uses calcium carbide slag instead of limestone, which also reduces energy consumption, improves the raw material production time, improves the burnability of the pellets, and improves the quality of the cement clinker. In addition, after the use of calcium carbide slag, the cost per ton of cement has dropped by 4-6 yuan, which has brought considerable economic benefits to the company, and it has benefited from preferential policies for national taxation. It has won many achievements and laid a solid foundation for the sustainable development of the company. The basis for the contribution to the rapid and healthy development of the economic zone on the northern slope of the Tianshan Mountains.