Economic Extraction and Recovery of REEs and Production of Clean Value-Added Products from Low-Rank Coal Fly Ash

Technology Partner: University of North DakotaAward Number: FE0031490

Project Duration: 11/16/2017 – 5/15/2019Total Project Value: $508,812

Key Technology Area: Separation Technologies
Project Partners: Pacific Northwest National Laboratory

The project’s objective is to develop an economically viable and tailorable rare-earth element (REE) extraction and concentration method for low-rank coal fly ash and bottom ash that produces a concentrate containing greater than or equal to two percent by weight total REE. This project will focus on low-rank (lignite and subbituminous) coal combustion/gasification ashes. The ash samples will be collected from industry partner facilities as well as from the existing sample database for North Dakota lignites at the University of North Dakota. The characterization to be performed will fully elucidate the abundance, form, and association of the REEs, both in the feed coals that produced the ash, and in the ashes. Additionally, the chemical composition, mineralogy, and morphology of the ash will be determined. Based on the characterization results, two ash samples will be

downselected for laboratory-scale REE extraction and concentration testing. The laboratory-scale testing will involve evaluation of ash pretreatment methods, dilute acid leaching, and solvent extraction testing, which will be followed by REE concentration testing at downselected conditions and materials. The project will also evaluate a novel method of value-added beneficiation of the clean fly ash. Finally, based on the experimental testing, a preliminary technical and economic analysis will be completed to estimate capital and operating expenses and product revenues. The project benefits are the development of a high- performance, environmentally benign, and economically viable technology for REE production from an alternative resource that will limit dependence on foreign supplies and strengthen the economic and national security of the United States.

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Seredin, V.V.; Dai, S. Coal Deposits as Potential Alternative Sources for Lanthanides and

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