Coal energy plays an important role in life and production and is an important source of energy and chemical raw materials in the world. Coal resources in our country have the characteristics of large reserves and wide distribution. Most of our country’s energy supply is obtained by burning coal. Fly ash is the main industrial waste after coal combustion. It is one of the industrial solid wastes with the largest emissions in my country. A large amount of fly ash has caused serious harm to the environment. At present, fly ash recycling methods are mainly concentrated in low value-added fields such as the preparation of cement, concrete building materials, and synthetic zeolites. In addition to containing a large amount of aluminum, silicon and other elements, fly ash also contains rich rare metal elements such as lithium, rubidium and gallium. By extracting and utilizing these rare metals, high value-added utilization of fly ash can be achieved. If lithium can be efficiently extracted from fly ash, it will not only solve the problem of fly ash pollution but also provide a new source of lithium resources.

Coal energy plays an important role in life and production and is an important source of energy and chemical raw materials in the world. Coal resources in our country have the characteristics of large reserves and wide distribution. Most of our country’s energy supply is obtained by burning coal. Fly ash is the main industrial waste after coal combustion. It is one of the industrial solid wastes with the largest emissions in my country. A large amount of fly ash has caused serious harm to the environment. At present, fly ash recycling methods are mainly concentrated in low value-added fields such as the preparation of cement, concrete building materials, and synthetic zeolites. In addition to containing a large amount of aluminum, silicon and other elements, fly ash also contains rich rare metal elements such as lithium, rubidium and gallium. By extracting and utilizing these rare metals, high value-added utilization of fly ash can be achieved. If lithium can be efficiently extracted from fly ash, it will not only solve the problem of fly ash pollution but also provide a new source of lithium resources.

Extracting lithium from fly ash can not only improve the production and supply capacity of my country’s existing lithium resources, but also provide ideas for solving environmental pollution problems caused by the accumulation of fly ash. In acidic environments, the more mature lithium extraction processes at this stage include solvent extraction, hydrochloric acid leaching, and adsorption. The use of extraction methods to extract lithium in acidic media has problems such as high requirements for extraction materials, high toxicity, and strong corrosion to equipment. Therefore, from an environmental perspective, extraction methods for lithium extraction in acidic media have serious problems of pollution and consumables. Under alkaline conditions, there are two main methods: precipitation and adsorption. Precipitation technology is relatively mature compared with other technologies. However, due to the large number of metal impurities in it, co-precipitation occurs easily, making separation difficult. With the rapid growth of global lithium resource consumption, lithium extraction from fly ash is expected to become a new source of lithium resources.