TY - JOUR
T1 - Alkaline residues and the environment
T2 - A review of impacts, management practices and opportunities
AU - Gomes, Helena I.
AU - Mayes, William M.
AU - Rogerson, Mike
AU - Stewart, Douglas I.
AU - Burked, Ian T.
PY - 2016/1/20
Y1 - 2016/1/20
N2 - Around two billion tonnes of alkaline residues are produced globally each year by industries such as steel production, alumina refining and coal-fired power generation, with a total production estimate of 90 billion tonnes since industrialisation. These wastes are frequently stored in waste piles or landfills, and can be an environmental hazard if allowed to generate dust, or if rainwater infiltrates the waste. This review will focus on the environmental impacts associated with alkaline residues, with emphasis on the leachates produced by rainwater ingress. Many alkaline industrial wastes can produce leachates that are enriched with trace metals that form oxyanions (e.g. As, Cr, Mo, Se, V), which can be very mobile in alkaline water. The management options for the residues and their leachates are also discussed, distinguishing active and passive treatment options. Potential reuses of these materials, in construction materials, as agricultural amendments, and in environmental applications are identified. The mechanisms of carbon sequestration by alkaline residues are assessed, and the potential for enhancing its rate as a climate change off-setting measure for the industry is evaluated. The potential for recovery of metals critical to e-technologies, such as vanadium, cobalt, lithium and rare earths, from alkaline residues is considered. Finally research needs are identified, including the need to better understand the biogeo-chemistry of highly alkaline systems in order to develop predictable passive remediation and metal recovery technologies.
AB - Around two billion tonnes of alkaline residues are produced globally each year by industries such as steel production, alumina refining and coal-fired power generation, with a total production estimate of 90 billion tonnes since industrialisation. These wastes are frequently stored in waste piles or landfills, and can be an environmental hazard if allowed to generate dust, or if rainwater infiltrates the waste. This review will focus on the environmental impacts associated with alkaline residues, with emphasis on the leachates produced by rainwater ingress. Many alkaline industrial wastes can produce leachates that are enriched with trace metals that form oxyanions (e.g. As, Cr, Mo, Se, V), which can be very mobile in alkaline water. The management options for the residues and their leachates are also discussed, distinguishing active and passive treatment options. Potential reuses of these materials, in construction materials, as agricultural amendments, and in environmental applications are identified. The mechanisms of carbon sequestration by alkaline residues are assessed, and the potential for enhancing its rate as a climate change off-setting measure for the industry is evaluated. The potential for recovery of metals critical to e-technologies, such as vanadium, cobalt, lithium and rare earths, from alkaline residues is considered. Finally research needs are identified, including the need to better understand the biogeo-chemistry of highly alkaline systems in order to develop predictable passive remediation and metal recovery technologies.
KW - Air pollution control residues
KW - Chromite ore processing residue
KW - Fly ashes
KW - Red mud
KW - Steel slag
UR - http://www.scopus.com/inward/record.url?scp=84958178548&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2015.09.111
DO - 10.1016/j.jclepro.2015.09.111
M3 - Review article
AN - SCOPUS:84958178548
SN - 0959-6526
VL - 112
SP - 3571
EP - 3582
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
ER -