A geopolymer solidified material based on manganese tailings base and its preparation method

Abstract

The invention discloses a geopolymer solidified material based on manganese tailings and a preparation method thereof. The raw materials are composed of solid raw materials and liquid raw materials; the solid raw materials are composed of 4.5-5.5% cement and 4.5-5.5% manganese tailings according to the mass percentage , 89-91% polymetallic contaminated soil, the three components are 100%; the liquid raw material is an aqueous solution containing an alkali activator and a water reducer, the mass concentration of the alkali activator is 1-2%, and the mass concentration of the water reducer The concentration is 0.8-1.0%; the solid raw material and the liquid raw material are mixed according to the water-cement ratio of 0.30-0.40. The present invention utilizes soluble SiO in manganese tailings 2 and Al 2 o 3 , Ca(OH) 2 Hydration reaction occurs, which makes kaolin, C-S-H, C-A-H and sodium zeolite gel materials continue to increase, ensuring that the compressive strength of the manganese tailings-based polymer solidified body continues to increase; the acidity in manganese tailings Oxides can also promote active glassy SiO 2 and Al 2 o 3 Dissolution, to ensure the hydration reaction; plus the hydroxide of Mn on Pb 2+ , Zn 2+ It has a strong specific adsorption capacity and has a good physical wrapping effect on heavy metals such as Pb and Zn.

Description

technical field [0001] The invention belongs to the technical field of polymetallic soil remediation, and in particular relates to a manganese tailings-based geopolymer solidified material and a preparation method thereof. Background technique [0002] With the upgrading of the non-ferrous metal industry, the retreat of the city into the park, the second into the third, leaving a large number of polluted sites, resulting in serious heavy metal pollution in the soil around the site. Heavy metal pollution in soil is often dominated by a certain heavy metal, accompanied by the presence of other elements, that is, compound pollution with the coexistence of multiple metals. Polymetallic composite pollution poses a serious threat to food safety, drinking water safety, regional ecological environment, living environment health, sustainable economic and social development and even social stability. Therefore, there is an urgent need to promote research on multi-metal composite cont...

AI Technical Summary

Problems solved by technology

However, there are two main problems in the actual application process: high carbon footprint and hysteresis reaction. Specifically, heavy metals and calcium hydrates will form a dense composite film, which hinders cement hydration, and during cement hydration, when the pH is greater than At 13 o'clock, the hydroxyl group of the metal precipitate dissolves, which increases the amount of cement added, resulting in high energy consumption and CO 2 Therefore, it is urgent to develop green curing materials with low carbon and low alkalinity

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