In recent years, China’s ceramsite raw material structure has undergone important changes, the proportion of solid waste ceramsite has increased significantly, and the market share of urban construction waste ceramsite and sludge ceramsite has increased significantly. At present, in addition to the more mature fly ash ceramsite and sludge ceramsite, various other solid wastes such as coal gangue, tailings, steel slag, and even fly ash after incineration of domestic garbage have all industrialized production of ceramsite manufacturers.
(1) Sludge ceramsite
The use of sludge to make ceramsite is a hot spot in the industry’s recent development. The country increased the production capacity of ceramsite with sludge as raw material by more than 2 million cubic meters last year alone. The sludge currently mainly comes from river and lake dredging sludge, municipal sewage sludge, and industrial enterprise sludge. Because all localities have certain economic compensations for sludge disposal. For example, Shanghai 300-500 yuan per ton, Zhejiang Ningbo 200-300 yuan per ton, Taizhou 150-250 yuan per ton, Huzhou 150-250 yuan per ton, Jiangsu Nanjing 250 yuan per ton. At present, most ceramsite manufacturers are using or trying sludge to produce ceramsite, and have achieved certain economic and social benefits.
(2) Tailings ceramsite
There are 12,655 tailings ponds in my country, and tailings have become the largest solid waste output and stockpiled in my country, which has caused serious environmental problems and huge safety hazards. Although the land was covered and re-cultivated after the storage was closed, the land area was far from enough to make up for the area occupied by the tailings pond in the early stage, causing the loss of land resources. Using tailings to prepare ceramsite is one of the important ways to utilize tailings as a resource.
(3) Steel slag ceramsite
The slag firing ceramsite technology effectively overcomes the problem of late expansion of steel slag and cannot be used for building materials. It reduces the firing temperature of ceramsite by taking advantage of the iron-rich characteristics of steel slag, which is lower than that of shale clay ceramsite. The need to mine natural stone and mineral resources is an emerging technology worth promoting for energy saving and emission reduction.
(4) Coal gangue ceramsite
Coal gangue is a by-product of coal mining and is one of the largest industrial solid wastes in my country. The large accumulation of coal gangue not only wastes land, but also pollutes the environment, and can even cause serious geological disasters. Therefore, the problem of rational utilization of coal gangue needs to be solved urgently. The use of coal gangue to prepare ceramsite not only solves the pollution problem of coal gangue, but also makes reasonable use of industrial solid waste and turns waste into treasure, which has certain social, economic and environmental benefits. At present, many coal mining enterprises, the following resource utilization companies, are conducting research and development of coal gangue ceramsite.
(5) Ceramsite made from domestic waste fly ash
With the rapid development of China’s social economy and the acceleration of urbanization and the rapid improvement of people’s living standards, the amount of garbage generated in the process of urban production and life has also increased rapidly. Domestic garbage occupies land, pollutes the environment, and is harmful to people’s health. The impact of this has become more obvious. The massive increase in municipal solid waste has made it more and more difficult to dispose of waste. The resulting environmental pollution and other issues have gradually attracted widespread attention from all walks of life. The use of domestic waste for incineration power generation is a common disposal method, and a large amount of waste incineration fly ash will be produced every year. This kind of fly ash is a hazardous waste, and how to carry out subsequent treatment has become another topic. The fly ash ceramsite is produced with waste incineration fly ash as the main raw material. After the harmless treatment, the leaching toxicity of heavy metals meets the control indicators of relevant national standards. The performance of the ceramsite product meets the requirements of GB/T17431.1, realizing the harmlessness of fly ash. , Resource disposal, has made a significant contribution to the promotion of the industry’s technology, and made the ceramsite industry have the functions of resource utilization and safe disposal of hazardous waste.