Synthesis and Characterization of Calcium Carbonate Nanoparticles via Bacterial Mineralization in Steel Slag Comprising Cementitious Materials
Synthesis and Characterization of Calcium Carbonate Nanoparticles via Bacterial Mineralization in Steel Slag Comprising Cementitious Materials
复制标题
含胶凝材料钢渣中细菌矿化碳酸钙纳米粒子的合成与表征
DOI：
10.1166/sam.2020.3733
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发表时间：
2020-05
影响因子：
0.9
通讯作者：
Qian Chun-Xiang
中科院分区：
文献类型：
--
作者：
Yi Haihe;Qian Chun-Xiang
Bacteria-induced mineralization is a new technique to produce calcium carbonate in steel slag for the preparation of building materials. Calcium carbonate nanoparticles were precipitated as a result of the enzymatic activity of Bacillus mucilaginous subtilis in steel slag. The
crystal structure and morphology of the calcium carbonate precipitate were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM), while thermal properties were
studied by thermogravimetric-differential scanning calorimetry (TG-DSC) analysis. The experimental results showed that the microstructure of calcium carbonate precipitate induced by the reproductive enzymes of Bacillus mucilaginous differs from the chemical precipitation in simulated
pore solution of steel slag. Powder XRD patterns confirmed the formation of Bacillus mucilaginous subtilis-induced calcium carbonate with an average particle size of 42.1 nm, while the average particle size of the chemically synthesized calcium carbonate was 59.3 nm. Compared with the
chemical synthesis, we found that the decomposition temperature of calcite by bacterial precipitation was higher than that for the chemically-precipitated calcite. The compressive strength improved with the amount of bacterial content. Bacterial mineralization could accelerate the rate of
carbon sequestration in the mineralization process. The content of calcium carbonate in microbial mineralized steel slag increased obviously. The compressive strength of steel slag mortar with 1.5% bacterial reached up to 51.5 MPa, the compressive strength increased over 50% compared with
the carbonized steel slag mortar. The micron-size calcite by bacterial mineralization resulted in a more compact structure. Our study suggests that microbial mineralization technology is a good method to utilize steel slag for building materials.
