Rare Earth Element Extraction from Acid Mine Drainage

Rare Earth Element Extraction from Acid Mine Drainage September 9, 2020

RARE EARTH ELEMENTS (REEs) – WHAT ARE THEY? • 18 of the transition metals from the Periodic Table – Lanthanide and Actinide series + Scandium and Yttrium • Critical Metals in many new technology platforms • No current major US resource exists – REEs are currently sourced from China (90%+) and Australia • US Department of Energy and Department of Defense has indicated that these are critical items to the US’s National Security Graphic courtesy of NETL

WHERE ARE REEs FOUND? • While called “rare”, the elements are actually quite abundant but in very low concentrations at most locations in the world except for a few locations in China and Australia • REEs have been known to exist in Coal and Coal By-products for over 30 years but in very low concentrations • The US Do. D and Do. E have recently engaged in more significant research of sources of REEs due to Executive Order 13817, issued December 20, 2017 by President Trump indicating that new, domestic REE resources must be determined and developed • Included other various metals such as manganese, which is critical to high-grade steel production • Multiple groups – led by a consortium through the National Energy Technology Laboratory (NETL) – have engaged in finding REEs in Coal and Coal By-products

ARE REEs IN AMD and WHY IS IT THERE? • The short answer is Yes! • They exist in AMD as part of the same process that creates AMD in the first place: • • • Iron pyrite is oxidized to sulfuric acid and free iron in water via a reaction of the pyrite with the oxygen in the air The solid metals in the rock strata become dissolved in this highly-acidic solution and the REEs act the same way as other metals; where they exist, they are leached out of the rock Recent research has shows higher levels of REEs exist in the sedimentary rock surrounding coal – i. e. boney/partings • • REE levels in surrounding rock can approach 3 X that of the coal itself The REEs were placed in this sedimentary rock via ancient volcanic eruptions that dispersed the metals at the bottom of shallow oceans in the Eastern US coalbeds

KNOWN CONCENTRATIONS OF REEs IN COAL • • USGS – in the 1980’s – conducted significant research into the REE content in coal as trace elemental analyses were done for many boreholes in the Eastern US Coal Basin Below is a summary of Epic research into typical Somerset County, PA coal and it’s REE content (in ppm, or grams per metric ton): • • • Interesting results – Kittanning coals tend to be much richer in total REEs (~30% higher than average coal) Scandium is always ~6% of the total REE content of a sample Somerset County coal seams are typically “rich” in some critical REEs such as Neodymium and Yttrium REE content in coal can be extended to REE content in AMD on a % basis via correlation to aluminum content in the AMD water Typically higher Heavy REE percentage vs Light REE percentage (~60% heavy)

THE HARD PART – HOW TO GET REEs OUT OF AMD • NETL-funded research has focused on the extraction of REEs from typical alkaline treatment sludge and large-flow AMD sites • • • Concentrations are typically very low in sludge with abundant gangue metals Larger flows (1, 000 GPM+) are targeted to increase volume yields even though TREE content in the AMD can be comparatively low vs. lower-flow sites All generate a solid then use typical metal-extraction processes to split out REEs • Epic research has focused on smaller, higher-concentration locations and the enrichment of the TREE content of the AMD: • • • First step is to remove some of the pure water from the AMD, creating a concentrated AMD Use the concentrated AMD to leach high-TREE bearing feedstock – for instance, coal refuse – to create a pregnant liquor solution, or PLS Precipitate the dissolved metals in the PLS via one of a variety of methods (salts precipitation, fractional precipitation, etc. ) Generate a 2 -5% by weight TREE solid Patent pending process

THE EPIC PROCESS AMD Treated Water Discharge to Environment Initial Water Removal Stage 1 Pure Water Stage 1 AMD Concentrate Secondary Water Removal Stage 2 Pure Water Stage 2 AMD Concentrate Solids Precipitation

HOW DOES THE EPIC PROCESS FIT INTO THE SUPPLY CHAIN? Raw Feedstock Materials Enriched Solid Feedstock (i. e. AMD, coal fly ash, sedimentary rock, etc. ) Y Separation into Individual Metals Sc Nd Separated REO REE Extraction To Mixed REO

WHAT IS THE MARKET POTENTIAL? • • • The right example shows what a common AMD site might generate on a daily and yearly basis Pennsylvania alone has over 2, 000 low-flow abandoned AMD sites; many more are maintained by coal operators Appalachia (WV, PA, MD, KY, TN, & VA) has thousands of sites that are like the example site shown; >80% of all AMD sites are less than 100 GPM flow rate with average of ~25 GPM Epic technology opens the door to capturing enough TREEs to supply the US Department of Defense need every year All “green” technologies require some level of REEs (wind turbines, solar panels, electric vehicles, etc. ) Example Site Flow Rate = 100 GPM Raw Water TREE Content = 0. 70 ppm Concentrate TREE Content = 4. 7 ppm Leachate (PLS) TREE Content = 10 ppm Leachate % = ~5% of flow rate Grams TREE generated/day = 270 grams Average Value of TREE = $0. 50 per gram In-Situ Daily Value = $135/day In-Situ Value Per Year = ~$50 k

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