Preparation method of ceramsite by using river sediment as raw material

Abstract

The invention provides a preparation method of ceramsite by using river sediment as a raw material. The method comprises the following steps: adding excitable solid powder wastes (such as fly ash, slag and volcanic ash), strong alkali materials (such as quick lime and sodium hydroxide) and other substances into the river sediment to prepare residual soil, and carrying out multi-stage granulation; then, coating the surface of the ceramsite obtained through multi-stage granulation by adopting a sulphoaluminate cement-based material with rapid hardening, early strength and low porosity, so that the sulphoaluminate cement coated ceramsite with the porous interior and the compact shell structure is prepared, and the negative effects of the unfired ceramsite on the aspects of harmful metal migration and odor volatilization are reduced; and meanwhile, the compressive strength of the single ceramsite is improved. The method provided by the invention has the advantages of low energy consumption, no tail gas pollution, low equipment investment, high production efficiency, easily controllable production process and good industrialization prospect.

Description

technical field [0001] The invention belongs to the technical field of water treatment, in particular to a method for preparing ceramsite using river bottom mud as a raw material. Background technique [0002] With the increasing urban development process, high population density, heavy river pollution load, and lack of clean water supply, the water environment capacity is small, resulting in a series of river basin water environment problems such as black and odorous rivers and ecological degradation in the past ten years. While actively preventing and controlling the entry of pollutants into the river, attention should also be paid to the endogenous pollution of the river caused by polluted sediment. [0003] A large amount of organic matter, nitrogen and phosphorus nutrients and heavy metals deposited in the river sediment are important causes of black and odorous water bodies. Heavy metal pollutants in water bodies are not easy to degrade, and most of them enter the sed...

AI Technical Summary

Problems solved by technology

However, according to the government's relevant regulations on "designating high-polluting fuel combustion-free areas", highly polluting fuels such as coal products cannot be used as fuel for calcination in many first-tier cities, and the calcination method has certain restrictions in terms of fuel sources and clean energy costs.

At the same time, the firing process consumes a lot of energy and exhaust gas, and requires complex exhaust gas recovery and treatment devices, which increases the production cost of lightweight ceramsite

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