Geochemical controls on leaching of lignite-fired combustion by-products from Greece

Izquierdo, María; Koukouzas, Nikolaos; Touliou, Sofia; Panopoulos, K.D.; Querol, Xavier; Itskos, Grigorios

doi:10.1016/j.apgeochem.2011.04.013

Cited by 41 publications

(43 citation statements)

References 40 publications

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“…Subsequently, a dynamic experimental analysis of lithium leaching was conducted. The aluminum and lithium extraction efficiencies obtained in the present study were higher than those obtained in previous acid leaching studies [16,21] under the same condition. This was attributed to the desilication process and the high-pressure conditions.…”

Section: Effect Of Hydrochloric Acid Concentrationcontrasting

confidence: 54%

“…Hydrochloric acid concentration has a significant effect on the leaching rates of lithium and aluminum [16]. Figure 7 shows that the aluminum and lithium extraction efficiencies increased with hydrochloric acid concentration from 1 to 8 mol/L, with maximal rates of 79.5% and 83.6%, respectively.…”

Section: Effect Of Hydrochloric Acid Concentrationmentioning

confidence: 87%

“…Previously, aluminum has been recovered from CFA using hydrometallurgy techniques such as solvent extraction [13], acid leaching [14][15][16][17][18], alkaline leaching [19][20][21], and acid/alkali combination methods [22]. The CFA may be pre-processed before leaching using auxiliary reinforcement methods, such as lime stone sintering [6], soda lime sintering [23], and ammonium sulfate sintering [14,24].…”

Section: Introductionmentioning

confidence: 99%

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An Efficient Approach for Lithium and Aluminum Recovery from Coal Fly Ash by Pre-Desilication and Intensified Acid Leaching Processes

Qin

Kang

et al. 2017

Metals

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A novel technique was developed for the recovery of lithium and aluminum from coal fly ash using a combination of pre-desilication and an intensified acid leaching process. The main components of the high-aluminum fly ash were found to be Al 2 O 3 and SiO 2 , and the Al/Si ratio increased from 1.0 to 1.5 after desiliconization. The lithium content of the coal fly ash met national recycling standards. The optimal acid leaching conditions, under which the leaching efficiencies of lithium and aluminum were 82.23% and 76.72%, respectively, were as follows: 6 mol/L HCl, 1:20 solid to liquid ratio, 120 • C and 4 h. During the hydrochloric acid pressure leaching process, spherical particles of desilicated fly ash were decomposed into flakes. Part of the mullite phase was dissolved, and most of the glass phase leached into the liquor. The generation of the silicates hindered lithium transport, which decreased the leaching rate of lithium. This work suggests that the preprocessing is a promising option for effective recovery of high-aluminum and fly ash-associated lithium.

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Section: Effect Of Hydrochloric Acid Concentrationcontrasting

confidence: 54%

Section: Effect Of Hydrochloric Acid Concentrationmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

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An Efficient Approach for Lithium and Aluminum Recovery from Coal Fly Ash by Pre-Desilication and Intensified Acid Leaching Processes

Qin

Kang

et al. 2017

Metals

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“…The leachable concentrations range over several orders of magnitude as a function of the mode of Ca occurrence and concentration in the fly ash, the proportion of each phase and the leaching test performed. With only water, the amounts of Ca leached could easily fall in the 100-15000 mg/kg range (Iwashita et al, 2005;Izquierdo et al, 2011;Medina et al, 2010;Moreno et al, 2005). The water extractable proportions measured for a large set of data are in the 7-14% range (Moreno et al, 2005;Nugteren, 2010;Ward et al, 2003),…”

Section: Calciummentioning

confidence: 99%

“…pH) of the ash. Typical values for alkaline ash range from 700 to 15000 mg/kg SO 4 2- (Izquierdo et al, 2011;Moreno et al, 2005).…”

Section: Sulphurmentioning

confidence: 99%

Leaching behaviour of elements from coal combustion fly ash: An overview

Izquierdo

Querol

2012

International Journal of Coal Geology

Self Cite

625

379

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Coal-based power generation produces over 750 Mt of coal ash per year globally, but under 50% of world production is utilised. Large amounts of fly ash are either stored temporarily in stockpiles, disposed of in ash landfills or lagooned. Coal ash is viewed as a major potential source of release of many environmentally sensitive elements to the environment. This paper encompasses over 90 publications on coal fly ash and demonstrates that a large number of elements are tightly bound to fly ash and may not be easily released to the environment, regardless of the nature of the ash. This review provides an extensive look at the extent to which major and trace elements are leached from coal fly ash. It also gives an insight into the factors underlying the leachability of elements and addresses the causes of the mobility. The mode of occurrence of a given element in the parent coal was found to play an important role in the leaching behaviour of fly ash. The amount of calcium in fly ash exerts a dominant influence on the pH of the ash-water system. The mobility of most elements contained in ash is markedly pH sensitive. The alkalinity of fly ash attenuates the release of a large number of elements of concern such as Cd, Co, Cu, Hg, Ni, Pb, Sn or Zn among others, but at the same time, it enhances the release of oxyanionic species such as As, B, Cr, Mo, Sb, Se, V and W. The precipitation of secondary phases such as ettringite may capture and bind several pollutants such ash As, B, Cr, Sb, Se and V.

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Coal Combustion Residuals and Health

Kravchenko

Ruhl

2021

Practical Applications of Medical Geology

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Geochemical controls on leaching of lignite-fired combustion by-products from Greece

Cited by 41 publications

References 40 publications

An Efficient Approach for Lithium and Aluminum Recovery from Coal Fly Ash by Pre-Desilication and Intensified Acid Leaching Processes

An Efficient Approach for Lithium and Aluminum Recovery from Coal Fly Ash by Pre-Desilication and Intensified Acid Leaching Processes

Leaching behaviour of elements from coal combustion fly ash: An overview

Coal Combustion Residuals and Health

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