Recovery of Rare Earth Elements from Coal Fly Ash through Sequential Chemical Roasting, Water Leaching, and Acid Leaching Processes. / Pan, Jinhe; Hassas, Behzad Vaziri; Rezaee, Mohammad et al. In: Journal of Cleaner Production, 10.2020, p. 124725. Research output: Contribution to journal › Article › peer-review

Rare Earth Elements in Coal-combustion Fly Ash and Their Potential Recovery. March 2022. DOI: 10.1002/essoar.10510791.1. Authors: James C Hower. University of Kentucky. Allan Kolker. Heileen Hsu ...

Germanium recovery from coal fly ash (FA) leachates by solvent extraction procedures was studied. Tests at pilot plant scale were performed in order to design industrial equipment. Based on the experimental results, mass balances and McCabe-Thiele diagrams were applied to determine the number of steps of the SX stage. Different …

The Coal Gold Agglomeration (CGA) process was developed some years ago and has the advantage in that gold is recovered by a procedure which has little or no negative impact on the environment ...

Fly ash, produced during the burn ing of coal, is a fine grained solid derived from noncombustible constituents of coal, such as clay minerals and quartz. When coal is burned, REEs are retained and enriched in the fly ash and, as a result, fly ash has long been considered a potential resource for REEs (Goldschmidt, 1935; Seredin and Dai, …

We present the first data on the mode of occurrence of Au in fly ashes from the Wulantuga and Lincang power plants in China, which burn high-Ge coal. Gold occurs as fine-grained drop-like ...

It is well established that the chemical composition of coal fly ash depends primarily on the chemistry of the source coal and the combustion process. As ash is derived from the inorganic minerals in the coal such as quartz, feldspars, clays and metal oxides, the major elemental composition of coal ash is similar to the composition of a …

The process of the recovery of precious metals and other high-valued elements from coal and coal combustion products is justified and developed. The argumentation is provided for the method of ...

The recovery of alumina from coal fly ash was pioneered by Grzymek in Poland in the 1950s [29], and was developed mainly because of the bauxite embargo during the Cold War. The recovery process was based on the auto-disintegration of sinter containing calcium aluminates and dicalcium silicate [30]. The sinter was mixed with …

The conventional leaching process of REEs from coal ash primarily involves mineral acids such as HCl, HNO 3, and H 2 SO 4 as leachents 6 combined with solvent extraction as a subsequent step ...

The effect of acid concentration on the recovery of rare earth elements from coal fly ash was investigated. Results indicated that acid concentration had a significant effect on rare earth element ...

The present paper gave a comprehensive description of the recovery of gallium from production of alumina from high-alumina coal fly ash with predesilication and lime-soda sinter combination process.

Coal combustion processes generate a tremendous volume of tailings in the form of bottom ash, fly ash, and slag, which indicates a promising source for industrial recovery due to rare earths being associated with incombustible materials rather than combustible carbon materials (Seredin and Dai, 2012, Seredin and Dai, 2012b, Honaker …

The recovery of REEs in the SLM configuration, which involved the impregnation of the solvent in a hydrophobic membrane, was slower than the LEM process. However, the SLM process was notably more selective for the heavy (and higher value) REEs, while the conventional extraction and LEM processes were more selective …

Figure 2. Summary of magnetite recovery results. The feed ash was up-graded to from 12.1% magnetic to 58.8% magnetics by spiral concentration with an overall yield of 8.1%. The spiral product was then screened to remove +100 mesh material, which further improved the grade to 68.0% magnetics.

In both cases insufficient mixing will occur, resulting in a lower gold recovery. Activated carbon has a bulk density of 0.500 g/ml and a pore volume of 0.8 ml/g. If the pore volume is filled with water having a density of 1 g/ml and add the two values, the density of wet carbon is typically 1.3 g/ml. 17 | P a g e.

During the coal combustion process, the lithium in the raw coal is secondarily enriched in the fly ash due to the melting-condensation effect. Sun, Yang et al. (2012 ) found that the lithium concentration of fly ash in the Pingshuo mining area was as high as 345 μg/g, exceeding the industrial target of 120 μg/g for lithium recovery in coal ...

In the following sections, the characteristics of different solid wastes including fuel-oil ash, coal ash and sewage sludge and their bioleaching for the recovery of metals as value-added products are discussed. 8.1. Fuel-oil ash8.1.1. Chemical characteristics. The fly ash collected by a cyclone collector is called CY fly ash.

The digestion reaction with NaOH lixiviants also causes coal fly ash to become more porous, making it advantageous in the organic acid-leaching process at the REEs recovery stage. The utilization of the desilicated residue produced from the digestion process in acid leaching effectively increases the overall REEs recovery from 32.2% to …

More information: Laura Stoy et al, Preferential Recovery of Rare-Earth Elements from Coal Fly Ash Using a Recyclable Ionic Liquid, Environmental Science & Technology (2021). DOI: 10.1021/acs.est ...

The relationship between the recovery ratio and the mass rate of coal ash/Na 2 S 2 O 3 for Ge and W were demonstrated in Fig. 3 (b). It can be observed that Ge in coal ash present the plateau of recovery ratio at around till 1.6 mass rates of coal ash/Na 2 S 2 O 3. It then declined with the increase of mass rate.

The recovery of REEs in the SLM configuration, which involved the impregnation of the solvent in a hydrophobic membrane, was slower than the LEM process. However, the SLM process was notably more selective for the heavy (and higher value) REEs, while the conventional extraction and LEM processes were more selective for the light REEs.

The main goal of a coal fly ash waste valorization process is to extract and separate the valuable metals (such as REEs) from the coal fly ash, while recovering any …

Ash Beneficiation for REE Recovery. Wencai Zhang 1, John Groppo2 and Rick Honaker 1. 1 University of Kentucky, Mining Engineering Department, 504 Rose Street, Lexington, KY 40506; 2University of ...

The lab has adapted its process to extract rare earth elements from coal fly ash, bauxite residue and electronic waste. Photo by Jeff Fitlow. "The strategy is general for various wastes," Bing said. "We proved that the REE recovery yields were improved from coal fly ash, bauxite residue and electronic wastes by the same activation process

Abstract and Figures. This paper presents an extensive review of the coal agglomeration process, including oil agglomeration theory, characterization methods of coal hydrophobicity, and the main ...

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 …

Environmental Science, Chemistry. 2016. ABSTRACT This study is mainly focused on the direct adsorption of low concentration gallium from the feed solution in pre-desilication soda-lime sintering process from coal fly ash. The adsorption…. Expand.

However, few reports on the simultaneous recovery of PGMs from SAC and the synthesis of glass–ceramic via a co-treatment process with coal fly ash (CFA) can be found in the existing literature. Coal fly ash (CFA), an industrial byproduct generated from thermal power plants, can induce serious environmental impacts via direct landfills [18,19 ...

The graphic is a scheme depicting an ionic liquid leaching process for sustainable rare-earth element recovery from coal fly ash. Use of a recyclable ionic liquid to extract rare-earth elements fro...