Research on composite municipal solid waste incineration bottom ash and granulated blast furnace slag based geopolymers with sodium alginate for sealing coal seam gas drainage boreholes

This study has created geopolymer sealing materials from sodium alginate (SA), granulated blast furnace slag (GBFS), and municipal solid waste incineration bottom ash (MSWI-BA) to see how well they can seal coal seam gas drainage boreholes. In comparison to ordinary cement sealing material (CSM) and neat MSWI-BA based geopolymer, composite geopolymer sealing material (SIG) with 0.1 wt% SA has the advantages of appropriate setting time, improved fluidity, and increased compressive strength. Additionally, SIG demonstrated a slight expansion that aids in maintaining the durability of the seal. However, when compared to neat geopolymer, the addition of sodium alginate increased porosity and permeability slightly, but not to levels higher than CSM. Based on the microstructural characterization, a mechanism for the formation of SIG with coordination crosslinking structure in the network of C-A-S-H and N-A-S-H gels was proposed. The created composite geopolymer material, which is based on MSWI-BA and GBFS, therefore, has a lot of potential for use as sealing materials in coal seam gas drainage boreholes.