Dry Covers Applied to Coal Tailings

• Published in: Mine water and the environment Vol. 41; no. 3; pp. 666 - 678
• Main Authors: Soares, Anderson Borghetti, Possa, Mario Valente, de Souza, Vicente Paulo, Soares, Paulo Sergio Moreira, de Aguiar, Marcos Fábio Porto
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2022; Springer Nature B.V
• Subjects: Acid mine drainage; Acidic soils; Bottom ash; Clay; Climate change; Coal; Coal mining; Design; Drainage; Earth and Environmental Science; Earth Sciences; Ecotoxicology; Effluents; Environmental impact; Field study; Fly ash; Geology; High density polyethylenes; Hydrogeology; Industrial Pollution Prevention; Mine drainage; Mine tailings; Mine wastes; Mineral Resources; Mineralogy; Moisture content; Permeability; Precipitation; Pyrite; Rain; Seasonal variations; Seepage; Soil; Soil layers; Soils; Submarine springs; Tailings; Technical Article; Water balance; Water content; Water pollution; Water Quality/Water Pollution; Water seepage; Brazil; Dry covers; Unsaturated water flow; Acid mine drainage (AMD)
• ISSN: 1025-9112; 1616-1068
• DOI: 10.1007/s10230-022-00883-6

Covering coal mining tailings with layers of soil reduces the generation of acid mine drainage. These layers are designed to minimize water seepage and the flow of oxygen into tailing deposits. In Brazil, tailings from mineral coal processing are rich in pyrite, are often stored in piles, and are covered with layers of soil on the surface. This study provides results on the performance of four experimental soil cover models on tailings resulting from coal mining in southern Brazil. Pilot-scale physical models were constructed on-site, and the water balance of the covers, suction, volumetric moisture content, temperature in the tailings/cover layers, and quality of released effluent were measured. The covers designed with soil and bottom ash significantly reduced the volume of water seepage through the tailings and improved the quality of the generated effluents. Moreover, the results demonstrated that the performance of the cover depends on climate variations, and its behavior varies seasonally.