Coal waste derived soil-like substrate: An opportunity for coal waste in a sustainable mineral scenario

摘要

Proper coal waste management significantly reduces environmental impacts. An option to address this issue is to reduce coal waste accumulation by transforming it into soil. The objectives of this study were to process coal waste by turning it into a soil-like substrate - SLS (a kind of spolic technosol) and to evaluate plant growth and possible changes in sulfur speciation. Coal waste was desulfurized by gravity processing, ground, and amended with rice husk ash, steel slag, and sewage sludge to improve physical structure, adjust acidity, and provide organic matter as well as nutrients. Megathyrsus maximus var. maximus (Guinea grass) was cultivated in a SLS for 100 days (whole cycle). Results demonstrated healthy growth of Guinea grass. Plant growth, total sulfur and sulfur species (S-sulfate, S-pyrite, S-organic) were analyzed. Data indicated that soil mixtures underwent a 50% reduction of S-pyrite, an increase of S-organic and had high fertility measurements. The study showed promising results for the use of coal waste as a soil-like substrate to improve mining sustainability. (C) 2017 Elsevier Ltd. All rights reserved.