The invention provides a method for preparing a composite
flame retardant from ardealite. The method comprises the following steps: S1, preparing
gypsum particles; S2, preparing
slurry; S3, performing material wrapping; S4, filtering; S5,
drying; S6, placing at low temperature; S7, performing circular treatment; and S8, obtaining the finished product. According to the invention, the composite
flame retardant is prepared by compounding the mixed
slurry outside the
gypsum particles for multiple times, so that the
phosphogypsum can be further utilized, the stockpiling amount of the
phosphogypsum can be reduced, and the cost of the
flame retardant can be effectively reduced on the premise of not reducing the flame retardance; and a wrapping layer outside the prepared composite flame retardant is decomposed when heated to absorb heat on the surface of comburent, the surface temperature of the synthetic material filled with the wrapping layer in flame is reduced, meanwhile, a large amount of water is released to dilute
oxygen on the surface of the comburent, active
oxide generated through
decomposition is attached to the surface of the comburent,
combustion is further prevented, and the temperature of the
gypsum particles inside cannot be excessively increased and harmful substances cannot be generated.