The building block is prepared from the following raw materials in parts by weight: 30 to 60 parts of ardealite, 0.5 to 2 parts of
lime, 10 to 30 parts of
slag, 0 to 2.5 parts of
silica fume, 0 to 2.5 parts of
fly ash, 1 to 5 parts of
cement, a water
reducing agent with the
mass ratio of 0.5 to 1.5 percent of ardealite, 8 to 12 parts of water, 10 to 20 parts of an
acrylic acid metal salt
mixed solution, 0.5 to 2.5 parts of a
water repellent agent and 15 to 50 parts of aggregate, the
acrylic acid metal salt
mixed solution contains
calcium ions or / and
magnesium ions; through the in-situ
polymerization synergistic effect among the
cement, the
lime, the inorganic active material and the
acrylic acid metal salt solution, the inorganic-organic
hybrid gel efficiently and stably solidifies the
phosphogypsum, harmful ions are converted into insoluble and thermodynamically stable forms, and efficient and stable
phosphorus,
fluorine and heavy metal immobilization is achieved. The mixing amount of the
phosphogypsum is as high as 30-60%, the building block has good mechanical properties, the 28-day
compressive strength of the building block is greater than or equal to 30 MPa, and the
breaking strength is greater than or equal to 3.5 MPa; and through
surface modification treatment of the hydrophobic agent, a hydrophobic film is formed on the surface of the ardealite, the hydrophobic performance of the surface of the ardealite is enhanced, the
water resistance of the ardealite is improved, and the water
absorption rate of the building block is less than or equal to 5.0%. And the preparation process has the advantages of low cost, simplicity and convenience in operation, environment friendliness and the like.