The immobilization of Cr is important for the treatment of municipal solid waste incineration fly ash, and the solidification of Cr in cement-free materials has not been fully investigated. In this study, blast furnace slag-based cementitious materials were used as binders to immobilize Cr-bearing fly ash to prepare solidified materials. The environmental safety of Cr …
The Japanese Waste Disposal and Public Cleansing Law (Ministry of Health and Welfare, 1992) specifies necessary pretreatment methods to prevent leaching of heavy metals from MSWI fly ash before landfilling.In Japan, fly ash is generally stabilized using a dithiocarbamate chelating agent. Then it is solidified using Portland cement.
Numerous leaching studies of coal fly ash have demonstrated that the quantity of major and trace elements extracted can be extremely variable, depending on the nature of both the fly ash and the leaching solution (Brubaker et al., 2013; Van Der Sloot et al., 2011., Valerie, 2007). It is difficult for a new researcher to identify the suitable ...
The recent development of sustainable green cement technology has brought hope on fly ash for production alkali-activated cementitious materials (AACs), due to the high content of SiO 2 and Al 2 O 3 (the sum of SiO 2, Al 2 O 3, and Fe 2 O 3 is approximately 70 %). The practicability of using fly ash to produce AACs has been proven [[24], [25], [26]].Fly ash has …
Leaching behavior and comprehensive toxicity evaluation of heavy metals in MSWI fly ash from grate and fluidized bed incinerators using various leaching methods: A comparative study Science of The Total Environment, Volume 914, 2024, Article 169595
Coal fly ash can be used in in various configurations (e.g. as cap, bottom liner, or blending) at a mine site, but comparative studies investigating their capacity to control acid mine drainage are limited. Batch and column leaching experiments were conducted to investigate the effects of fly ash-mine tailings mix ratios and system configurations on leachate chemistry. Acidic mine …
Leaching study of fly ash is made by the analysis of leaches from open percolation leaching column experiment s over a period o f 274 d. Trace elements were observed within the regulatory limits. ... Garnets, Gold and Power in Late …
If piled fly ash gets exposure to rain or other precipitation, the harmful and heavy metals leach out and contaminate groundwater or surface water . This review aims to summarise the different leachability tests, analyse and study the transport of heavy metals through various models and leaching out of heavy metals from fly ash treated soils.
Vitolo et al. used this method for the recovery of V from a fly ash at temperatures of 650–1150 °C, followed by an acid leaching and oxidative precipitation of vanadium …
Alternative binders produced from waste for the stabilization of mining tailings (especially those considered hazardous) are important for waste management and sustainable engineering. Thus, this manuscript evaluated the leaching behavior of gold mining tailings stabilized/solidified by an alkali-activated binder (AAB) over wetting–drying cycles of durability …
The comparative leaching risk of multivalent elements, as per the RAC, for fly ash ranks in the order of As < Cr < Sb (Lou et al., 2023). This ranking is attributed to the low concentration and leaching potential of As in MSWI fly ash, which is considered to pose a negligible leaching risk.
Fly ash is a relatively common solid waste and has advantages in terms of particle size, distribution, and reactivity [ 2 ], particularly if it is a high-calcium fly ash (like class C fly …
Bhaskar S. et al.: Bioleaching of iron from fly ash using a novel isolated Acidithiobacillus ferrooxidans strain etc. 361 in the recovery of aluminium and iron by magnetic separa-tion and carbon floatation technique14.Elomaa and others claims acid leaching is more suitable in the recovery of iron
This two-step leaching of fly ash is an efficient combination for the mobilization of a high percentage of heavy metals from fly ash (Pb, Cd ≥ 90% and Cu, Zn 70-80%). The depletion of …
Coal Fly Ash (CFA) is a hazardous waste from coal-fired power plants, but has increasingly become a popular supplementary cementitious material for cement in the construction industry. As a secondary resource of REE, its main advantage lies in its fine particle size that eliminates the need for costly and energy-intensive comminution. In this study, the …
However, most REEs in coal fly ash are encapsulated in aluminosilicate glass, making it challenging to recover them through acid leaching. In this study, a sequential …
The process of extracting aluminum with sulfuric acid from high-alumina fly ash activated by roasting with Na2CO3 and NaOH as raw materials ware studied. The results revealed that the aluminum in fly ash activated by sodium carbonate reached 93.2% under the optimum conditions (30% H2SO4, 90°C, 120 min, and liquid-to-solid ratio was 5:1). …
Exploring relationships between various activations of granular activated carbon on silver and gold adsorption: A kinetic and equilibrium study. A Seyedhakimi, SA Bastami, S Ghassa, H Razavi, S Chehreh Chelgani ... Spent-medium leaching of germanium, vanadium and lithium from coal fly ash with biogenic carboxylic acids and comparison with ...
The maximum REEs recovery achieved through leaching of fly ash samples collected from 22 U.S. coal-fired power plants using concentrated nitric acid at high temperature (85–90 °C) was only 44%, and most of the recovery values were significantly lower (Taggart et al., 2016). Alkaline leaching using aqueous sodium hydroxide (NaOH) (to ...
Leaching of elements from bottom ash, economizer fly ash, and fly ash from two coal-fired power plants Int. J. Coal Geol., 94 ( 2012 ), pp. 337 - 348 View PDF View article View in Scopus Google Scholar
Renewable ammonium chloride-induced calcium leaching of gold and copper tailings and selective preparation of vaterite CaCO 3 by CO 2 mineralization. Author links open ... seawater brine, and industrial solid waste (e.g., steel slag, fly ash, incineration ash and calcium carbide slag) have been shown to be high-calcium materials that can be ...
Sandy grade alumina is a valuable intermediate material that is mainly produced by the Bayer process and used for manufacturing primary metallic aluminum. Coal fly ash is generated in coal-fired power plants as a by-product of coal combustion that consists of submicron ash particles and is considered to be a potentially hazardous technogenic waste. The present paper …
Three stage leaching of ashes significantly enriched the gold concentration. This paper investigates the enrichment of gold through combustion and ash-leaching techniques utilizing woody biomass as a fuel source.
This research aimed to characterize the physical, chemical properties of municipal solid waste incineration fly ash and investigate the leaching of heavy metals during Toxicity Characteristics ...
For choosing the most suitable leaching method according to specific situation, one must primarily consider the chemical and physical properties of wastes, the composition of the …
Fly ash is a combustion by-products retained in the exhaust gas scrubbing systems (e.g. in electrostatic precipitator). The high fugacity and content of hazardous substances, such as heavy metals, causes, that the storing is associated with many problems and possesses a threat to the environment [1].In Poland most of the demand for electricity and …
In the acid leaching method, 1 g of fly ash was b urned at 360 °C for 1 h first followed by 650 °C for 1 h. Then 3 ml of . concentrated HNO 3 and 5 ml of concentrated HClO 4 ...
With the increase of municipal solid waste (MSW) discharge and the development of the incineration technology, at least 10 million tons of MSW incineration fly ash (MSWIFA) is discharged annually in China (Wang and Fan, 2020).According to the 'Directory of National Hazardous Wastes' of China (Ministry of Ecology and Environment of the People's Republic of …
Fly ash is an industrial waste material that is repurposed as a soil stabiliser worldwide. In Thailand, many ground improvement projects utilise mixtures of cement and fly ash to stabilise weak soils. In this study, leaching mechanisms of arsenic, chromium, lead, and zinc from cement and fly ash stabilised soils were investigated in the laboratory.
Coal fly ash (CFA) is an increasingly prevalent byproduct that necessitates more resourceful and eco-friendly processing methods. Extracting aluminum from CFA is a crucial aspect of promoting sustainable development in the alumina industry. In this paper, a technique for comprehensive extraction of silica and alumina from circulating fluidized bed-based CFA is …
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