Investigation of the key factors favouring the biocementing effect of microbially induced calcite precipitation when applied to mine tailings

Recent research has suggested the applicability of microbially induced calcite precipitation (MICP) to improve wind erosion resistance across diverse media, from clay to sandy soils. While various factors influencing MICP performance have been investigated, comprehensive studies considering the synergistic interactions between biocementation media composition, dosages, available urease activity, and urea-calcium ratios are limited. Consequently, identifying key factors governing MICP during tailings biocementation remains crucial for optimizing treatment strategies. This is specially the case for MICP application for mine tailings biocementation, due to the limited available research dealing with this substrate. This research studied the effect of several factors, when biocementing mine tailings, using a factorial design. The results confirm the key role of the biocementation media dosage and the urea-calcium ratio, and their synergistic interaction during biocementation of tailings, as they determine the calcium and inorganic carbon available to produce calcium precipitates. Biocementation of tailings by applying MICP substantially improved surface strength, leading to a drastic reduction in wind erosion resistance. These results confirm the potential of MICP to become an interesting tool to reduce windblown dust emissions from tailings deposits. • MICP is a promising tool to mitigate windblown dust emissions from tailing deposits. • Dose of calcium and urea are key factors influencing biocementation behaviour. • A minimum dose of biomass exists over which no further effect can be observed.