The Influence of Microbial Agent on the Mineralization Rate of Steel Slag

Abstract

Bacteria-based mineralization is a new technique to use the steel slag. In this article, an experimental examination was performed to find out the steel slag advancement by the addition of the microbial agent that has the possibility to accelerate mineralization ability of bacteria. It is observed that, under natural and CO2 pressure curing conditions, the carbonation rate is significantly raised when microorganisms are added to the steel slag. The increased ratio of microorganisms leads to a better carbonation rate. The reaction products formed by bacteria mineralization were analyzed with the scanning electron microscope (SEM) and X-ray diffraction (XRD), and the amount of reaction products was examined by thermogravimetric analysis. The results show that the compressive strength and carbonation speed rose with the increase in microorganism content. Bacterial could accelerate the rate of carbon sequestration in the mineralization process. The compressive strength of steel slag with 1.5% bacterial could reach up to 51.5 MPa. The micron-sized and roughness mineralization product induced by microorganisms apparently resulted in a denser and compacted structure. The carbon depth increased by 50%, and the content of calcite increased by 3 times. These mineralization products would fill in the pore of steel slag cementitious materials and form the integrated and denser structure which produces more strength.

Effect of Steel Slag on Soil Fertility and Plant Growth

“…Ionization of steel slag is promoted by a large number of soil microorganisms, therefore, the effect of steel slag may be more effective in organic agricultural fields [30]. Since, the bacterial biomass is lower in the agricultural field cultivated with chemical fertilizers, so the effect of slag may be lower compared to the organic cultivation system.…”

Iron Elution from Iron and Steel Slag Using Bacterial Complex Identified from the Seawater

“…We also used a steel slag hydrated matrix (SSHM) for the screening of bacterial strains synthesizing biofilms. SSHM is made by blast furnace slag, ISS, and water [ 21 ]. In this research, CSMS and SSHM were supplied by Nippon Steel Co., Ltd.…”

“…The previous works reported that microbes were used for the bioleaching of ISS indicating that the physiological effect of microbes affect the metal elution of ISS [ 20 ]. Some special bacteria also induced the mineralization on the surface of ISS suggesting that bacteria can change the mineral phase of ISS [ 21 ]. In this research, microbes that promote iron elution from ISS were examined.…”