Solid waste-based porous materials, methods for preparing the same, and methods of ecological restoration of coal gangue hills by applying the same

A method of ecological restoration of a coal gangue hill by applying a solid waste-based porous material, comprising:

• S1. preparing a coal-based solid waste restoration material including:
• mixing the solid waste-based porous material, low-rank coal, and waste organic matter in a mass ratio of (3-6):(2-4):(2-6), while adding 0.1-0.3% of a microbial quick corrosion agent for aerobic fermentation for 10-30 days, wherein the solid waste-based porous material is obtained by:
• adding 40-80% of coal gangue powder, 0-40% of fly ash, 5-20% of cement, 0-10% of desulfurization gypsum, and 0-5% of lime into a granulator or a screening granulator;
• preparing a solution by adding 0.7-3% of a foaming agent into water;
• preparing particles with 1-8 mm of particle size in the granulator or screening granulator by spraying the solution several times into the granulator or screening granulator based on a liquid-solid ratio in a range from 0.6 to 0.8;
• and
• obtaining the solid waste-based porous material after flue gas curing;
• standing in a sedimentation tank for 7 days, and
• obtaining the coal-based solid waste restoration material with 1-8 mm of particle size after crushing and screening,
• S2. preparing a solid mycorrhizal agent including:
• adding a coal-based solid waste porous material with 2-5 mm of particle size into humus to obtain culture matrix,
• sprinkling host plant seeds inoculated with mycorrhizal spores into the culture matrix with a thickness of 10-20 cm, adding a nutrient solution, a formula of which is 945 mg/L of calcium nitrate, 607 mg/L of potassium nitrate, 115 mg/L of ammonium phosphate, 493 mg/L of magnesium sulfate, 2.5 ml/L of iron salt solution, and 5 ml/L of trace elements, pH=6.0, culturing for 1-6 months while maintaining 30-50% of humidity and 20-35° C. of temperature such that active spores and hyphae of mycorrhizal are all over the culture matrix,
• crushing plant roots and the culture matrix together to a size of the plant roots and the culture matrix being less than 0.6 cm to obtain mycorrhizal solid original agent,
• applying the mycorrhizal solid original agent to new culture matrix at a ratio of 10-15%, and
• cycling step S2 to obtain an expanded solid mycorrhizal agent;
• and
• S3. greening a leveled coal gangue hill and a slope of the coal gangue hill including:
• the greening the leveled coal gangue hill including:
• digging pits in the leveled coal gangue hill covered with soil,
• evenly sprinkling the coal-based solid waste restoration material obtained by step S1 and the solid mycorrhizal agent into each pit obtained by step S2,
• planting and straightening seedlings in the pit, filling soil until a surface of the pit is level with the ground, and
• pouring enough water in time;
• the greening a slope of the coal gangue hill including:
• preparing a slurry seeding material by mixing loess, the coal-based solid waste restoration material, the solid mycorrhizal agent, seeds, and water, and
• evenly spraying the slurry seeding material on the slope of the coal gangue hill.