Abstract: In view of the pollution caused by spodumene tailings stacking and improving passive fire resistance of building materials, this study prepared spodumene-based geopolymer Si-C-P flame-retarding coatings through chitosan hydrochloride modification technology. Cone calorimeter test results show that: Appropriate amount of chitosan hydrochloride （mass fraction of 0.8%） enhanced the flame retardant index （FRI） of the composite coating increasing from 1.00 to 3.52, and the total smoke production （TSP） decreased from 3 347.16 m2 to 1 688.66 m2. The acicular amorphous carbon formed by chitosan hydrochloride increased the specific surface area of the residue. The more resilient and robust Si-C-P composite residues formed, improving the flame retardancy of the geopolymer coating.

Key words: spodumene, flame retardant, chitosan, geopolymer, microstructure