Nowadays, many manufacturers use wet production technology, namely wet acidification processing method, in the production of activated clay. The production process includes processes such as bentonite hydration, sulfuric acid activation, water washing, drying, and crushing. The products produced by this process have a high acid content and require repeated water washing to reduce the acid content to the standard requirements of HG/T2569-94. The repeated washing process will produce a large amount of wastewater containing aluminum sulfate and unreacted sulfur-containing produced during the acidification reaction of bentonite. If these wastewater are directly discharged, it not only wastes a lot of resources, but also causes serious pollution to the environment.

In recent years, some methods have been proposed for the treatment and recycling of wastewater from the production of activated clay, such as lime neutralization method, calcium carbide slag neutralization method, acid recovery activation method, and the use of them to decompose porcelain clay to produce industrial water treatment agent aluminum sulfate, dissolve iron filings to produce green alum, etc. Some of these methods have effectively solved the problem of treating wastewater from the production of activated clay. The commonly used methods in China currently include:

Lime neutralization method: By adding lime, the acidity in wastewater can be neutralized, allowing sulfate ions, aluminum ions, and iron ions to form precipitates such as calcium sulfate, aluminum hydroxide, and iron hydroxide, which can be removed. However, these precipitates cannot be utilized and become new solid waste;

Decomposition method: The remaining sulfuric acid in the wastewater is used to decompose the porcelain clay, and the aluminum in the porcelain clay is leached into the solution. After purification and impurity removal, evaporation and crystallization, separation and drying, crushing and packaging, aluminum sulfate is obtained. This effectively utilizes the wastewater from the production of activated clay and obtains new resource resources such as aluminum sulfate;

Recycling method for producing polysilicate aluminum sulfate: Polysilicate aluminum sulfate is a new type of inorganic polymer flocculant, which is a composite product of polysilicate acid and aluminum salt developed on the basis of silicate and aluminum salt flocculants. Due to its advantages of good flocculation effect, low price, and low residual aluminum content in treated water, the research on this flocculant has attracted great attention from the water treatment industry both domestically and internationally. The flocculant is currently mainly made from industrial products such as sodium silicate, sodium aluminate, and aluminum sulfate through polymerization reaction;

Recycling and production of alum method: This method can not only recover and produce ammonium alum and potassium alum from the wastewater of activated clay production, but also produce alum products with good market demand. This not only solves the environmental pollution problem caused by wastewater, but also brings additional benefits to enterprises, which can be said to kill two birds with one stone. In the actual production process, manufacturers can choose the appropriate wastewater treatment method according to their own actual situation to solve the problem, which can increase the economic benefits of the enterprise and make a contribution to energy conservation and environmental protection.