High-concentration filling slurry of coal gangue and preparation method thereof

A high-concentration filling slurry of coal gangue, wherein the high-concentration filling slurry of coal gangue comprises following components in parts by mass:

• filling aggregate:
• 65-85 parts;
• the filling aggregate comprises coarse aggregate and fine aggregate;
• wherein the coarse aggregate comprises coal gangue particles with following gradations:
• 20-30 parts of coal gangue particles with a particle size ≥10 mm and ≤20 mm;
• 20-30 parts of coal gangue particles with a particle size ≥5 mm and <10 mm;
• and
• 10-20 parts of coal gangue particles with a particle size ≥1 mm and <5 mm;
• the fine aggregate comprises coal gangue particles with following gradations:
• 5-10 parts of coal gangue particles with a particle size ≥500 μm and <1 mm;
• 5-10 parts of coal gangue particles with a particle size ≥200 μm and <500 μm;
• and
• 5-10 parts of coal gangue particles with a particle size <200 μm;
• 0.001-0.01 part of a suspending agent;
• wherein the suspending agent comprises the following components in parts by mass:
• 1-10 parts of polycarboxylate and 1 part of sodium allyl sulfonate;
• 0.001-0.05 part of a dispersant;
• wherein the dispersant is sodium metasilicate or sodium disilicate;
• 0.01-0.1 part of an active agent;
• wherein the active agent comprises the following components in parts by mass:
• 1 part of desulfurization gypsum and 1-10 parts of water glass;
• 0.001-0.01 part of a water-fixing agent;
• wherein the water-fixing agent comprises the following components in parts by mass:
• 1 part of polyacrylamide, 1-5 parts of lignin and 1-10 parts of cellulose;
• and
• 20-35 parts of water.