Method for firing haydite from municipal sludge, loess and bentonite

Abstract

The invention discloses a method for firing haydite from municipal sludge, loess and bentonite, which comprises the following steps: taking 30-35% by weight of primary sludge, 45-50% by weight of loess and 16-22% by weight of bentonite, rolling, and mixing to homogenize the materials; and aging, granulating, screening, firing to swell the haydite, and cooling in the air. The bulk density of the haydite is 400-500 Kg / m<3>, the compression strength is 1-3.5 Mpa, and the water absorptivity for 1 hour is 8-10%. By directly firing the haydite from the primary sludge, loess and bentonite by using bran coats as fuel, the invention has the advantages of high sludge treatment capacity and low production cost, and can not generate secondary pollution in the production process; the granule size of the product is 1-26mm; and the product satisfies the requirements in Chinese Light-weight Aggregate (Haydite) Standard GB / T17431.1-1998.

Description

Technical field: [0001] The invention relates to a firing method for producing ceramsite, in particular to a method for firing ceramsite with sludge, loess and bentonite produced in sewage treatment plants such as urban sewage plants, wool textile mills, printing and dyeing factories, and paper mills. Background technique: Background technique: [0002] According to incomplete statistics, the daily sewage treatment capacity in the country is about 300 million m 3 Sludge is an extremely complex heterogeneous body composed of organic debris, bacterial cells, inorganic particles containing heavy metals, and colloids. The main characteristics are high water content, high organic content, easy to rot and smell, fine particles, colloidal liquid, it is a thick substance between liquid and solid, and cannot be separated from solid and liquid by precipitation. Because the sludge produced by urban sewage and wastewater treatment is rich in many pollutants, the treatment cost is ver...

AI Technical Summary

Problems solved by technology

[0011] Although there is a method for firing ceramsite using sludge or river sludge in the prior art, the existing method can only use dry sludge or river sludge alone, and the original sludge must be dehydrated and dried first, and then powdered coal ash, limestone, clay and other raw materials for firing, and some need to add ceramsite proppant to fire

The dehydration and drying treatment of sludge is not only costly, but also during the sludge dehydration and drying process, the volatilization of sewage odor in the sludge will lead to secondary pollution of the air at the treatment site, producing SO 2 , directly affect people's normal life and health, and clean water must be added during the mixing process, which consumes a lot of heat energy and water, and the cost of ceramsite firing is too high, which is very uneconomical. The ability to deal with sludge is also limited, so it is difficult to popularize and apply