Solidifying agent for composite heavy metal polluted soil and its preparation and application method

Abstract

The invention discloses a curing agent for compound heavy metal polluted soil as well as preparation and application methods of the curing agent. The curing agent is prepared from the following materials in percentage by mass: 40 to 65 percent of steel slag powder, 5 to 25 percent of light calcined magnesia and 20 to 45 percent of phosphate activated bone powder. The curing agent has the advantages that firstly, the curing agent can obviously reduce the mobility and the toxicity leaching amount of heavy metals in the heavy metal polluted soil, and is particularly applied to an acidic polluted land which is high in heavy metal content and contains various pollutants; after the polluted soil is repaired, the curing agent can be used as an environment-friendly material for recycling, so that the environmental risk during secondary development use of the polluted land is obviously reduced; moreover, as the raw materials are readily available, the curing agent is low in cost, easy to prepare, convenient to use and stable in effect and can be popularized and applied to curing and stabilizing repairing of the compound polluted land in a large scale.

Description

technical field [0001] The invention relates to the field of environmental geotechnical engineering, in particular to a curing agent for composite heavy metal polluted soil and a preparation and application method. Background technique [0002] With the adjustment of urban functions and urban layout in our country, enterprises originally located in urban centers and suburbs, such as chemical plants, metal smelting plants, and electroplating plants, have gradually shut down or retreated from cities to parks. However, the production process of industries and enterprises for many years , A large amount of pollutants have accumulated in the land left after their relocation, which not only brings resistance to the efficient use of the leftover land, but also brings serious safety hazards to the surrounding environment. In recent years, the "Soil Pollution Prevention and Control Action Plan" (Soil Ten Articles) promulgated by the government also regards the restoration of contamin...

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Problems solved by technology

Commonly used curing agents mainly include materials such as cement, lime, and phosphate, which have a good effect on the solidification and stabilization of heavy metals, but there are also a large number of disadvantages, such as high energy consumption for cement production and high greenhouse gas emissions; lime and phosphate are Non-renewable natural minerals, high cost, etc.; and a large amount of phosphate will seriously change the soil structure and further cause phosphorus pollution of groundwater and surface water

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