Experimental study on tailings cementation by MICP technique with immersion curing

Abstract

The filling mining method is an effective method for controlling ground stress and preventing surface subsidence in the mining field during exploitation of underground resources. Tailings can be utilized as the filling material, so as to realize the reuse of industrial waste. However, utilization of the traditional Portland cement as the cementing material for tailings leads to groundwater pollution. In addition, production of Portland cement results in consumption of a great amount of ore and air pollution. In this paper, a tailings cementation method by using the microbial induced calcite precipitation (MICP) technique with immersion curing is proposed. Tailings are cemented by the MICP technique with aerobic bacteria (Sporosarcina pasteurii) under a soaked curing environment. The variable control method is applied to investigate the factors influencing the cementation effects by the MICP technique with Sporosarcina pasteurii, including the bacterial solution concentration, the cementing solution concentration, the particle size of tailings, and the curing temperature. The results indicate that: when OD600 of the Sporosarcina pasteurii solution is 1.6, the urea concentration in the cementing solution is 0.75 mol/L, the tailings are raw materials without grinding, and the curing temperature is 30°C, the cementation effect is the best. In view of uneven calcification during MICP with Sporosarcina pasteurii, mixed Sporosarcina pasteurii and Castellaniella denitrificans are used for tailings cementation. Higher strength of cemented tailings is achieved. It is proved that the MICP technique with mixed aerobic bacteria and facultative anaerobes is an effective method for tailings cementation.

Enhanced Oil Recovery through Microbially Induced Calcium Carbonate Precipitation

“…The bacterium S. pasteurii (ATCC 11859) was chosen due to its well-documented ability to grow on solid surfaces and its capacity to precipitate calcium carbonate minerals under both aerobic and anaerobic conditions . The bacteria were cultivated in a growth medium before injection into the micromodels.…”

“…The bacterium S. pasteurii (ATCC 11859) was chosen due to its welldocumented ability to grow on solid surfaces and its capacity to precipitate calcium carbonate minerals under both aerobic and anaerobic conditions. 33 The bacteria were cultivated in a growth medium before injection into the micromodels. The growth medium was prepared by dissolving 20 g of yeast extract (CAS-NO: 8013012, MilliporeSigma) and 10 g of ammonium sulfate (CAS-NO: 7783202, Sigma-Aldrich) into 1 L of deionized (DI) that was then sterilized for 15 min at 121 °C in an autoclave.…”

Influencing factors on ureolytic microbiologically induced calcium carbonate precipitation for biocementation

“…(3) Oxygenic photosynthesis Gloeocapsa sp. PCC 73106 (Zhu et al 2021) Synechococcus pevalekii BDHKU 35101 (Sidhu et al 2022) Tolerance of most strains to alkaline environment No toxic by-products Cheap media for cultivation CO 2 limitation in sand Light dependent Slow growth rates during phototrophic cultivation Dhami et al (2014), Zhu et al (2015) Ureolysis Sporosarcina pasteurii (Ma et al 2020;Zhao et al 2019) Bacillus sphaericus (Sharma et al 2022) Bacillus cereus (Oualha et al 2020) Bacillus megaterium (Mukherjee et al 2022) Easy to control Cheap media components High calcium carbonate precipitation rates High tolerance of strains to alkaline enviroment Toxic ammonia as byproduct Production of urea coupled to CO 2 emissions Hammes and Verstraete (2002), Muynck et al (2010a), Stocks-Fischer et al (1999) Denitrification Castellianelle denitrificans (Jin et al 2022) Pseudomonas denitrificans (Hamdan et al 2017) By-products calcium formiate and calcium nitrate are commercial additives for cement Nitrite ions can inhibit corrosion Usage of carriers for alkaline environments necessary Erşan et al (2016) precipitation. The creation of the advantageous microenvironment results in the formation of crystals on the cell surface, ensuing in the encapsulation of the cell (Muynck et al 2010a).…”