Method for preparing haydite from urban sewage plant sludge

Abstract

The present invention discloses one kind of haydite produced with dewatered sludge, fly ash and clay as material and its production process, and belongs to the field of environment technology. The haydite is produced dewatered sludge, fly ash and clay as material, and through mixing and sintering at gradually raised temperature. It is yellow or brown spherical solid in the bulk specific weight of 650-750 kg / cu m, granular specific weight of 1050-1150 kg / cu m, water absorption of 5.80-10.8 %, and specific surface area of 2.29-5.56 sq m / g. The production process is simple and low in cost, and the haydite has light weight, high strength, small water absorption, great specific surface area and other features. The haydite has wide use in building, environment protection, metallurgy, chemical industry, and other industry.

Description

(1) Technical field [0001] The invention relates to a method for preparing ceramsite from urban sewage plant sludge, which belongs to the field of environmental technology. (2) Background technology [0002] Sewage plant sludge refers to the flocs produced in the process of water treatment. It contains a large amount of water, rich organic matter and nutrients such as N, P, and K. It also contains harmful substances such as heavy metals and pathogenic bacteria. If it is discharged arbitrarily without treatment , not only pollute the environment, but also a serious waste of resources. According to incomplete statistics, the national sewage discharge is 4.474×107m 3 / d, there are more than 100 sewage treatment plants of different scales and treatment levels. The amount of sludge produced every day is about 0.5%-1.0% of the sewage treatment volume. In addition to rich nutrients such as nitrogen and phosphorus, the sludge also contains a large amount of organic matter, heavy m...

AI Technical Summary

Problems solved by technology

The amount of sludge produced every day is about 0.5%-1.0% of the sewage treatment volume. In addition to rich nutrients such as nitrogen and phosphorus, the sludge also contains a large amount of organic matter, heavy metals and various pathogenic microorganisms. Large, perishable, unstable, and foul-smelling, if not properly treated, it will cause a wide range of secondary pollution; at the same time, the investment and operating costs of sludge treatment are huge (respectively accounting for 12% of the total cost of the sewage treatment plant- 30% and 20%-50%), so it is of great significance to seek cost-effective, harmless and resource-based pollution treatment and utilization technologies