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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Reactive CO 2 capture and mineralization of magnesium hydroxide to produce hydromagnesite with inherent solvent regeneration

Valorization of multiple low value streams including CO 2 emissions and magnesium-hydroxide bearing mine tailings to produce magnesium carbonate through reactive CO 2 capture and mineralization provides a less explored opportunity to manage several gigatons of CO 2 emissions. To resolve the feasibility of converting magnesium hydroxide to magnesium carbonate through reactive CO 2 capture and mineralization, CO 2 capture solvents such as sodium glycinate are harnessed to capture CO 2 and react directly with Mg(OH) 2 to produce hydromagnesite (Mg 5 [(CO 3 )4(OH) 2 ]·4H 2 O). This approach eliminates the energy-intensive step of producing high purity CO 2 associated with regenerating the solvent, and redissolving CO 2 to produce magnesium carbonate. Interestingly, while temperatures below 50 °C facilitate CO 2 capture, the mineralization kinetics are slow. However, at higher temperatures, accelerated carbon mineralization is favored by the faster kinetics of Mg(OH) 2 dissolution and precipitation of magnesium carbonate. Reacting Mg(OH) 2 at 90 °C with 15 wt% solids in the presence of 2.5 M sodium glycinate after 3 hours under well-stirred conditions results in an extent of carbon mineralization of 75.5%. The theoretical maximum extent of carbon mineralization when hydromagnesite is formed is 80%. Pre-loading CO 2 on the solvent is also an effective approach to ensure that sufficient CO2 is available for reactive CO 2 capture and mineralization, particularly when dilute CO 2 and N 2 mixtures are used. Higher extents of carbon mineralization are associated with an increase in the particle size and a reduction in the cumulative pore volume. These insights unlock the feasibility of harnessing reactive CO 2 capture and mineralization as a pathway to convert magnesium-hydroxide bearing resources into industrially relevant magnesium carbonate products.

Reactive CO2↗
DOE OSTI2024

Raman spectroscopic investigation of selected natural uranyl sulfate minerals

Uranyl sulfates are important constituents of uranium ores and represent a significant fraction of U(VI) minerals discovered in recent years owing to their propensity to form in mine tailings and legacy sites related to uranium exploration. Recently, we surveyed all published Raman spectra for uranium minerals and found significantly less easily accessible data available for uranyl sulfates relative to other groups of uranium minerals (Spano et al. 2023). In that work, we described average spectra for groups of uranyl minerals to understand common vibrational spectroscopic features attributable to similarities in oxyanion chemistry among U(VI) minerals, but only data for three uranyl sulfate minerals were included in the study. The present work reports on Raman spectra collected for 18 additional uranyl sulfate minerals. In conclusion, to better understand underlying structural and chemical features that give rise to spectroscopic observables, we relate differences in structural topology, charge-balancing cations, and locality of origin to features observed in the Raman spectra of selected natural uranyl sulfates.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2023

RECLAIM: Electrochemical Lithium and Nickel Extraction with Concurrent Carbon Dioxide Mineralization

This project aims to develop technologies toward the production of Li and Ni from CO 2 -reactive minerals and rocks that contain Ca and Mg, while sequestering CO 2 . The technologies include acoustic stimulation and electrolytic proton production, which use electricity to liberate valuable metal ions from the surrounding mineral matrix at sub-boiling temperatures (~20-80°C). Feedstocks include Li/Ni/Ca/Mg-rich igneous and sedimentary rocks and minerals such as holmquistite, hectorite, lateritic Ni ores enriched in Mg-rich serpentine. Other examples of feedstocks that could be used include coarse grained orthocumulate, mine tailings, etc. In the first step, the electrolytic breakdown of water to H + and OH – (as well as O 2 and H 2 ) will be induced by applying an electric potential to simultaneously produce acidity and alkalinity. The solid feedstocks will be dissolved in the acidic anolyte under acoustic stimulation. Solubilized species will then undergo separation using our unique Li + -selective membranes driven by electrodialysis, leading to concentration of Li as soluble lithium silicate, from which Li 2 CO 3 can be derived by reaction with CO 2(g) while supplying cathode alkalinity. Also at the cathode, stepwise electrolytic precipitation of metal hydroxides, including Ni(OH) 2 , Ca(OH) 2 , and Mg(OH) 2 is performed along a cascade reactor in which both the applied potential and pH increase downstream, thereby simultaneously extracting and separating the metals. Finally, exposure of Ca(OH) 2 and Mg(OH) 2 to dilute CO 2 will result in CO 2 uptake in the form of Ca and Mg carbonates. The primary accomplishments include sample procurement and characterization. Progress has been made on precursor identification and mapping, establishing protocols for assessing metal extractability under sonication, and preliminary technoeconomic analysis (TEA) and life cycle analysis (LCA).

36 MATERIALS SCIENCE↗
DOE OSTI2023

Cradle-to-Gate Life Cycle Analysis Baseline for United States Coal Mining and Delivery

The goal of this study is to highlight the environmental impacts from upstream coal production to its delivery at a power plant. This study is meant to characterize different coal basins, coal types, and mine types used to produce electric power in the North American Electric Reliability Corporation (NERC) regions in the United States using a functional unit of 1 kg of coal. The boundary of this study includes underground or surface extraction, water use at the mine, ventilation, coal handling, coal cleaning, mine tailing disposal, and transportation via conveyer belt, truck, ocean vessel, barge, and train. See the following URLs for accompanying documents: NETL Coal Baseline Model - Transportation Inventories: https://www.netl.doe.gov/energy-analysis/details?id=27ea1ba4-6ea9-4ee5-8b32-d7fce7f4e1e0. NETL Coal Baseline Model - Basin Inventories: https://www.netl.doe.gov/energy-analysis/details?id=0f290eed-5e4b-4b5f-bec0-36b0ea89c6e5. NETL Coal Baseline Model - Excel file: https://www.netl.doe.gov/energy-analysis/details?id=0dc18730-4214-4878-8a0f-d1941c45123c. NETL Coal Baseline Model - Open LCA model: https://www.netl.doe.gov/energy-analysis/details?id=0c0dde04-0d3c-4c7f-bd33-2745e061b8e0.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2024

Abstract for CRADA between National Energy Technology Laboratory and Carbon To Stone, Inc.

The National Energy Technology Laboratory (NETL) and Carbon To Stone (CTS), Inc. (Participant) will collaborate on a techno-economic assessment (TEA) and life cycle assessment (LCA) of CTS’s carbon dioxide removal (CDR) technology under an awarded project from the Department of Energy’s Direct Air Capture Pre-Commercialization Technology Prize. CTS has developed a technological platform that captures carbon dioxide (CO2) from air and mineralizes it into durable carbonates using alkaline industrial residues such as steel slag and mine tailings. In addition, CTS’s technology uses electrochemistry to recover value-added energy critical metals (ECMs) from these residues. NETL has expertise in CDR TEA and LCA development. The collaboration between CTS and NETL aims to quantify the performance, cost and lifecycle impacts of CTS’s technology and produce LCA and TEA models that can accelerate development and deployment of this technology.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1973

Automatic photointerpretation for land use management in Minnesota

The author has identified the following significant results. The Minnesota Iron Range area was selected as one of the land use areas to be evaluated. Six classes were selected: (1) hardwood; (2) conifer; (3) water (including in mines); (4) mines, tailings and wet areas; (5) open area; and (6) urban. Initial classification results show a correct classification of 70.1 to 95.4% for the six classes. This is extremely good. It can be further improved since there were some incorrect classifications in the ground truth.

Swanlund, G. D.↗
DOE OSTI2022

Results from Electrochemical Leach Experiments under the DOE Technical Assistant Program

The activities described in this (report) are related to the analysis and testing of graphite and mine tailing samples provided by the Recipient for the extraction and recovery of embedded metals. This report focused on recovery of platinum group metals (PGMs), which appear in relatively high abundance, particularly technically important elements ruthenium and rhodium. Work performed involved assessment of materials followed by extraction tests using two methods. A novel electrochemically-driven route was compared to a chemical route for extraction of the metals. The electrochemically driven route showed similar results while producing the lixiviant in the electrochemical cell, hence reducing chemical requirements.

42 ENGINEERING↗
DOE OSTI2023

Clean Energy Technology Applications on US Mine Land: Technical Analysis

As the United States transitions toward a clean energy economy, an opportunity exists for redeveloping the more than 17,000 mine land sites located across the nation with clean energy technologies, which have a combined potential for generating more than 85 GW of clean electricity. This report provides an overview of the potential of demonstrating and deploying clean energy projects on current and former mine land. Clean energy project refers to a project that demonstrates one or more of the following technologies: solar; microgrids; geothermal; direct air capture; fossil-fueled electricity generation with carbon capture, utilization, and sequestration; energy storage, including pumped storage hydropower and compressed air energy storage; and advanced nuclear technologies. The report discusses the following technologies and their potential for creating jobs and generating tax revenue that would result in direct and indirect benefits to the local economy: Solar photovoltaics (PV) is being developed on current and former mine land in various parts of the world, including the United States. This approach is attractive because it requires limited infrastructure investment and would utilize the bare surfaces of mines and tailing ponds. Solar resource availability may be greater in the southern regions, including the Interior and Appalachian Basins and the southwestern United States. However, since some mine land sites include areas of significant change in elevation, the deployment of PV on mine land may require sophisticated planning to account for shading and irradiance, or may require regrading of the areas. PV does not create significant environmental risks and generally does not face public resistance; Geothermal systems are often spatially and genetically associated with ore deposits, and in some cases, they have been discovered while in search for epithermal mineral resources. Numerous diverse geothermal applications have been employed at mine land around the world, including power generation, mineral extraction from geothermal brines, process heating, direct use for other mining operations, and direct use for non-mining operations and subsurface energy storage, including geothermal heat pumps. Case studies highlighting these applications provide key lessons relating to identifying drivers and barriers to geothermal resource deployment and can be used to create screening tools for identifying the types and locations of mine land most amenable to utilizing geothermal resources; Carbon capture, utilization, and sequestration technologies include direct air capture (DAC) and enhanced weathering. DAC technologies include air contactors, regeneration systems, and CO 2 compression systems. Captured CO 2 can be converted to valuable feedstocks or possibly injected into abandoned subsurface mines where it would be absorbed by alkaline rock waste and mine tailings or by the porous minerals along the walls of the mine. DAC systems can be coupled with energy sources such as wind, solar, grid, or geothermal. Many DAC systems require a source of water or steam; however, some are expected to be net producers of water. Local impacts of DAC systems are expected to be low, and are related to land footprint, material disposal, and upstream impacts of energy and material production; Compressed air energy storage is an established energy storage technology in salt caverns. It has the potential for implementation in underground mines by pressurizing and storing a large amount of air using electrical compressors when excess electricity is available. When a need for discharge emerges, the air is used to spin turbines and produce the necessary volume of electricity. Abandoned or unused mine openings, including shafts, adits, access tunnels, and mined workings of any orientation, offer potential for vast amounts of compressed air energy storage if the site characteristics meet operational requirements; Pumped hydropower storage can be implemented in surface and subsurface mines. In surface mine applications, both reservoirs may be located in a mine pit or artificial reservoirs made of excavated materials. In subsurface mines, the lower reservoir may be implemented by waterproofing and flooding mine shafts and tunnels. The water is then pumped from the lower reservoir to the upper reservoir during periods of low load and high production, and it is discharged through the turbines during periods of peak demand. The potential environmental damages associated with acidity of mine water or the presence of toxic chemicals incentivizes the development of closed-loop technologies, in which water circulates inside the pumped hydropower facility without being discharged into the external water basins; Advanced nuclear energy technologies include small modular reactors, which can be deployed locally to produce electricity and heat. Such units require seismic stability and a supply of cooling water, but population constraints may exist in some areas. Therefore, remote mine land could represent an optimal location for siting advanced nuclear energy technologies.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

The influence of exploration activities of a potential lithium mine to the environment in Western Serbia

The proposed exploitation of the Jadar Valley lithium/borate deposit in Serbia, by the Rio Tinto Corporation, indicates that it would become large-scale processing of boron- and lithium-containing ore. It would be one of the world’s very first lithium mines in populated and agricultural area. The company claims that the envisioned mining will be in accordance with environmental protection requirements. The Jadar Valley deposits have been claimed to cover 90% of Europe’s current lithium needs. Yet, local opposition to the mining has arisen due to potential devastating impacts on groundwater, soil, water usage, biodiversity loss, and waste accumulation. Research drilling by the mining company has already produced environmental damage, with mine water containing high levels of boron leaking from exploratory wells and causing crops to dry out. Furthermore, our investigations reveal substantially elevated downstream concentrations of boron, arsenic, and lithium in nearby rivers as compared to upstream regions. Additionally, here we show that soil samples exhibit repeated breaches of remediation limit values with environmental consequences on both surface and underground waters. With the opening of the mine, problems will be multiplied by the tailings pond, mine wastewater, noise, air pollution, and light pollution, endangering the lives of numerous local communities and destroying their freshwater sources, agricultural land, livestock, and assets.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Radiocarbon analysis as a method for verifying atmospheric CO 2 uptake during carbon mineralization

Sequestration of atmospheric CO 2 is required to constrain the warming of Earth’s climate. Carbon mineralization refers to the precipitation of carbonate minerals by reaction of CO 2 and Mg- and Ca-rich rocks; if the source of the CO 2 is atmospheric and the precipitated carbonate is protected from subsequent dissolution, this process at sufficient scale may be able to reliably draw down atmospheric greenhouse gas levels. Such reactions occur passively in ultramafic settings and previous work has demonstrated that they actively draw down local CO 2 (g) concentrations. However, a method for unambiguously attributing the sequestered carbon solid product to atmospheric sources is still lacking. Here, we test if radiocarbon can be used to verify that the carbon being incorporated into carbonate minerals during carbon mineralization is atmospheric in origin. Additionally, samples from recently exposed ultramafic sites are analyzed and the results demonstrate the utility of this technique for verifying true atmospheric carbon reduction.

58 GEOSCIENCES↗
DOE OSTI2023

Vitamin interdependencies predicted by metagenomics-informed network analyses and validated in microbial community microcosms

Abstract Metagenomic or metabarcoding data are often used to predict microbial interactions in complex communities, but these predictions are rarely explored experimentally. Here, we use an organism abundance correlation network to investigate factors that control community organization in mine tailings-derived laboratory microbial consortia grown under dozens of conditions. The network is overlaid with metagenomic information about functional capacities to generate testable hypotheses. We develop a metric to predict the importance of each node within its local network environments relative to correlated vitamin auxotrophs, and predict that a Variovorax species is a hub as an important source of thiamine. Quantification of thiamine during the growth of Variovorax in minimal media show high levels of thiamine production, up to 100 mg/L. A few of the correlated thiamine auxotrophs are predicted to produce pantothenate, which we show is required for growth of Variovorax , supporting that a subset of vitamin-dependent interactions are mutualistic. A Cryptococcus yeast produces the B-vitamin pantothenate, and co-culturing with Variovorax leads to a 90-130-fold fitness increase for both organisms. Our study demonstrates the predictive power of metagenome-informed, microbial consortia-based network analyses for identifying microbial interactions that underpin the structure and functioning of microbial communities.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2014

Beneficiation of Stillwater Complex Rock for the Production of Lunar Simulants

The availability of pure, high calcium plagioclase would be a significant asset in any attempt to manufacture high-quality lunar simulants. A suitable plagioclase product can be obtained from materials obtained from the Stillwater Complex of Montana. The access, geology, petrology, and mineralogy of the relevant rocks and the mill tailings are described here. This study demonstrates successful plagioclase recovery from mill tailings produced by the Stillwater Mine Company. Hydrogen peroxide was used to remove carboxymethyl cellulose from the tailing. The characteristics of the plagioclase products are shown and locked grains are identified as a limit to achievable purity. Based on the experimental results, flowsheets were developed showing how these resources could be processed and made into 'separates' of (1) high calcium plagioclase and (2) orthopyroxene/clinopyroxene with the thought that they would be combined later to make simulant.

Rickman, D. L.↗
DOE OSTI2022

Direct observation of Mn distribution/speciation within and surrounding a basidiomycete fungus in the production of Mn-oxides important in toxic element containment

Biogenic manganese (Mn) oxides occur ubiquitously in the environment including the uranium (U) mill tailings at the Ningyo-toge U mine in Okayama, Japan, being important in the sequestration of radioactive radium (Ra). To understand the nanoscale processes in Mn oxides formation at the U mill tailings site, Mn 2+ absorption by a basidiomycete fungus, Coprinopsis urticicola, isolated from Ningyo-toge mine water samples, was investigated in the laboratory under controlled conditions utilizing electron microscopy, synchrotron-based X-ray analysis, and fluorescence microscopy with molecular pH probe. The fungus’ growth was first investigated in an agar-solidified medium supplemented with 1.0 mmol/L of Mn 2+ , ± Cu 2+ (50 – 200 µM), ± Zn 2+ (50 – 200 µM), or ± diphenyleneiodonium chloride (DPI) (50 – 100 µM) at 25 °C. The results revealed that Zn 2+ has no significant effects on the Mn oxides formation, whereas Cu 2+ and DPI significantly inhibit both fungal growth and Mn oxidation, indicating superoxide-mediated Mn oxidation. During the interaction of Mn 2+ with the fungi in solution medium at the initial pH of 5.67, a small fraction of Mn 2+ infiltrated into the fungal hyphae within 8 h, forming a few tens nm-sized concentrates of soluble Mn2+ in the intracellular pH of ~6.5, which can be released back to solution within a day as shown in a subsequent releasing experiment. After 1 day of incubation, Mn oxides began to precipitate on the hyphae, which were characterized to be fibrous nanocrystals with a hexagonal birnessite-structure, these forming spherical aggregates with a diameter of ~1.5 µm. When the fungi were reacted using the Ningyo-toge mine water, the Mn concentration decreased at a rate of 1.0 mmol·day-1 per unit dry weight. The nanoscale processes associated with the fungi derived from the Ningyo-toge mine area provides additional insights into the existing mechanisms of Mn oxidation by filamentous fungi at other U mill tailings sites under circumneutral pH conditions. Such processes add to the class of reactions important to the sequestration of toxic elements.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1980

Application of remote sensing to state and regional problems

Progress is reported in the following areas: remote sensing applications to land use planning Lowndes County, applications of LANDSAT data to strip mine inventory and reclamation, white tailed deer habitat evaluation using LANDSAT data, remote sensing data analysis support system, and discrimination of unique forest habitats in potential lignite areas of Mississippi. Other projects discussed include LANDSAT change discrimination in gravel operations, environmental impact modeling for highway corridors, and discrimination of fresh water wetlands for inventory and monitoring.

Miller, W. F.↗
NASA NTRS1981

Application of remote sensing to state and regional problems

The objectives, accomplishments, and future plans of several LANDSAT applications projects in Mississippi are discussed. The applications include land use planning in Lowandes County, strip mine inventory and reclamation, white tailed deer habitat evaluation, data analysis support systems, discrimination of forest habitats in potential lignite areas, changes in gravel operations, and determination of freshwater wetlands for inventory and monitoring. In addition, a conceptual design for a LANDSAT based information system is discussed.

Miller, W. F.↗