Landfill mining (LFM) involves excavating and processing solid waste from active or closed landfills to reduce mass, temporarily remove hazardous materials, and recover recyclables, combustibles, soil, and landfill space. It also improves soil aeration for future use. The process includes a conveyor system with machines for excavation, sieving, and sorting. LFM remediates poorly designed landfills, upgrades those failing environmental standards, and uses simple or complex equipment for different levels of material recovery and purity.
Tools and Machinery
Excavators and front-end loaders move waste mass onto conveyor belts, which feed into rotating trommels or vibrating screens. These screens separate soil from solid waste based on the intended use of the recovered material. A 2.5-inch screen is used for soil used as landfill cover, while a smaller mesh screen is employed for construction fill or similar uses, removing small metal, plastic, glass, and paper pieces.
Trommel screens are effective for landfill reclamation, while vibrating screens are smaller, more portable, and easier to set up. Large screen holes allow most waste to pass through, leaving oversized non-processable materials, which are removed. Coarse trommel leads to fine rotating trommel, separating soil from mid-sized non-biodegradable, mostly recyclable materials. Electromagnets remove metal debris, and an air classifier can separate organic material. Front-end loaders load these materials onto trucks for processing or sale, with on-site manual processing if transportation costs are prohibitive.