This portal houses data showing the results of REE field sampling and analyses of coal and coal by-products. The focus of this task is to characterize the bulk elemental concentration and mineralogy of REEs in coal and coal-byproduct materials during the initial collection phase and, as processing steps are completed, provide data needed to determine the best path forward.


Preliminary NETL Sample Data
This Excel workbook, consisting of multiple tabs, summarizes NETL R&IC (Research and Innovation Center (formerly ORD – Office of Research and Development) REE field sample inventory and analytical characterization results for coal and related by-product materials that were collected from different coal regions, in various stages of the process, at various organization locations. The focus of this study is to characterize the bulk elemental concentration and mineralogy of rare earth elements in all coals and coal by-product material including: mineral matter associated with coal, fly ash, bottom ash, and post-processing/post-use materials among others.

Samples and data were collected and reflected as screening for the best available materials for use as resource materials for potential separation and recovery of REEs.

The NETL FWP REE analyses are reported on an ash basis.

Sampling and analytical efforts were performed by the following team members: Evan Granite, Elliot Roth, Tracy Bank, and Pete Rozelle.

[Download File v8.4] [Version History] [Download File (11/2019)]

REE and Coal Open Geodatabase
A collection of open and public data that contains REE and Coal data that covers the US coal basins.

[Download File]

REE and Coal Open Geodatabase Geocube Collection
The REE and Coal Open Database is an online collection of subsurface contextual data from publicly available geological, geochemical, and geospatial resources. These data align to and support execution of NETL’s REE coal assessment method. The database includes basin- and national-level spatial datasets, in addition to other non-spatial data that support the assessment approach. Data in this collection are sourced from a range of authoritative, public sources, including NETL, U.S. Geological Survey (USGS), Energy Information Administration (EIA), and state geological surveys.

[Geocube Collection]

Guidance on Bulk Elemental Analysis of Solids*

There are many digestion procedures that can be employed for inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma optical emission spectrometry (ICP-OES) analysis (bulk elemental analysis) of solid coal by-products.  One method employed by NETL-RIC is described below.  Note that it is also critical for the lab to determine the percent recoveries of the rare earths and other elements from certified reference materials.  This serves as a check on the digestion procedure, as well as the analytical procedure.  Also note that ICP-OES has inferior detection limits for the rare earths as compared to ICP-MS.

In the NETL digestion procedure, solid samples were prepared by mixing pulverized sample with calcined LiBO2 (lithium metaborate) at a ratio of 1:8.  Prior to fusion, samples were mixed by stirring with a platinum rod in a 99.95% platinum crucible.  The open crucibles were heated to 1100°C for five minutes in a Phoenix microwave muffle furnace (CEM).  After 5 minutes, the melt was removed from the oven and allowed to cool to a homogeneous glass.  The glass was digested in 5% HNO3 on low heat with stirring.  To ensure that the sample glass was completely digested, the platinum crucibles were rinsed 3x with 5% HNO3 and the sample was diluted to a final volume of 100 ml.  These samples were further diluted in 2% HNO3 before analysis to determine the optimal balance between internal standard recovery and limit of detection.  For solid samples containing significant carbon content, samples were dried and ashed in a Leco Thermogravimetric Analyzer (TGA701) for one hour under nitrogen at 107°C for drying and then for five hours under air at 550°C for ashing.


“Analysis of Rare Earth Elements in Geologic Samples using Inductively Coupled Plasma Mass Spectrometry”

Tracy Bank, Elliot Roth, Phillip Tinker, Evan Granite, DOE Topical Report, available on the NETL REE EDX website.

All results recorded in this template will be made publicly available on this EDX portfolio site.

NETL Contacts

Jessica Mullen
Technology Manager
Critical Minerals Sustainability

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