Dewatered sludge solidifying agent

Abstract

The invention relates to a dewatered sludge solidifying agent which comprises silicate cement, modified fly ash, fine sand and calcium sulfate, wherein the modified fly ash accounts for 5-7wt% of the silicate cement, the fine sand accounts for 1-3wt% of the silicate cement, and the calcium sulfate accounts for 0.6-1.4wt% of the silicate cement. The preparation method of the modified fly ash comprises: baking fly ash at the temperature of 280-320 DEG C for 40-70 minutes, taking out for cooling, sealing and storing for later use, wherein and the use amount of the dewatered sludge solidifying agent is 2-10wt% of dewatered sludge, and the water content of the dewatered sludge is 30-60%. The dewatered sludge solidifying agent is suitable for solidifying modification of sludge generated in a water conservancy project, civil engineering and wastewater treatment, and has short solidification time; and the obtained modified soil has the advantages of high strength, small void ratio and no secondary pollution.

Description

technical field [0001] The invention relates to a curing agent for curing and modifying dewatered sludge, which belongs to the field of geotechnical materials. Background technique [0002] my country has a vast territory and is a country with a large amount of silt resources in the world. There is great potential for the development of silt recycling and comprehensive utilization. According to the survey and statistics of relevant departments, only domestic lakes and rivers have an annual collection volume of at least 70 million tons of silt, plus urban sewer silt, the total annual collection volume can be more than 10,000 tons. Collecting silt is beneficial to dredging rivers, preventing water eutrophication and purifying the urban environment, and the comprehensive utilization of silt can turn harm into benefit. [0003] Judging from the existing river and lake dredging projects in China, most of the landed mud is disposed of by solidification in the yard. This method d...

AI Technical Summary

Problems solved by technology

This method dehydrates and solidifies the sludge by adding solidification and cementitious materials such as cement and lime into the sludge slurry. This method has the following obvious disadvantages in large-scale dredging: first, the slurry must be continuously output during large-scale dredging, and all Cement and lime are mixed into the mud, and the project volume is too large to be completed in a short period of time; secondly, a large amount of silt cannot be mixed evenly with cement, lime and other cementitious materials, and serious secondary pollution will still be formed when the rain washes away; thirdly, To meet the solidification requirements, a large amount of cement and lime needs to be added, which is costly, and the total volume of waste after solidification increases; finally, the biocompatibility of the solidified product after such a large amount of cement and lime treatment is destroyed. , generally can only be landfilled, and resource utilization is difficult

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