Modified iron tailing sand, preparation and application of sand

The invention discloses modified iron tailing sand which is prepared by mixing and then modifying raw materials including, by weight, 2-5 parts of antibiotic mushroom dregs or biogas residues and 3-8parts of iron tailing sand. The modified iron tailing sand is stable in adsorption performance and less affected by pH (potential of hydrogen) values and temperature. Compared with unmodified iron tailing sand, the modified iron tailing sand has the advantages that heavy metal ion and phosphorus adsorption performance is greatly improved, and waste can be turned into wealth while antibiotic residues in the antibiotic mushroom dregs are removed. The invention further provides preparation of the modified iron tailing sand and an application of the modified iron tailing sand. In order to acquirethe modified iron tailing sand with excellent performance and high porosity and without antibiotic residues, a proper preparation process is provided. By the aid of procedures such as granulation, themodified iron tailing sand