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Full-Text Articles in Engineering
An Acid Baking Approach To Enhance Rare Earth Element Recovery From Bituminous Coal Sources, Ahmad Nawab
An Acid Baking Approach To Enhance Rare Earth Element Recovery From Bituminous Coal Sources, Ahmad Nawab
Theses and Dissertations--Mining Engineering
Rare earth elements (REE) are a group of 17 elements typically classified as light and heavy rare earth elements, which play a crucial role in developing the latest technologies for energy, defense, and medical sectors. Even though REEs have been found in more than 200 minerals, only bastnaesite, monazite and xenotime are commercially exploited for REE extraction. However, the recent exponential increase in REE demand has spurred countries such as the United States into research for the extraction of REEs from secondary sources such as coal, acid mine drainage, and coal ash. Several coal sources (e.g., Fire Clay seam coal) …
Characterization Of Rare Earth Elements In The Illinois Basin Coals, Alireza Valian
Characterization Of Rare Earth Elements In The Illinois Basin Coals, Alireza Valian
Theses and Dissertations--Mining Engineering
The purpose of this study is to characterize the distribution and occurrence of rare earth elements (REEs) in the coal and coal-related material from the Illinois Basin. For characterizing the distribution of REEs, 17 core samples were investigated from various parts in the basin. Also, several individual samples from coal preparation plants and isolated geological occurrences were included in the study. In result, the average REE concentrations were calculated on a bed-to-bed basis, although the distribution of REEs in the coal beds was found laterally and vertically heterogeneous. A number of trends were found that describe the variations. Most importantly, …
Leaching Characteristics Of Rare Earth Elements From Bituminous Coal-Based Sources, Xinbo Yang
Leaching Characteristics Of Rare Earth Elements From Bituminous Coal-Based Sources, Xinbo Yang
Theses and Dissertations--Mining Engineering
The demand for rare earth elements (REEs) has increased over the last decade due to applications in high technology devices including those in the defense industry. The recovery of REEs from primary sources such as rare earth minerals are viable using physical separations followed by chemical processing. However, weak market values and environmental concerns have limited the viability of such operations. On the other hand, REE recovery from secondary sources such as apatite ore, bauxite waste, and waste recycling, provides an opportunity to take advantage of a resource that does not require mining costs as well as other associated costs …
Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo
Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo
Theses and Dissertations--Mining Engineering
The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition …
Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick
Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick
Theses and Dissertations--Chemical and Materials Engineering
Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries. The …
Sustainable Disposal Of Coal Processing Waste Streams, Mohammad Rezaee
Sustainable Disposal Of Coal Processing Waste Streams, Mohammad Rezaee
Theses and Dissertations--Mining Engineering
Modern coal preparation facilities incorporate a wide array of solid-solid and solid-liquid separation processes for rejecting mineral matter to meet market specifications. The coarse mineral matter is typically placed into engineered refuse piles whereas the fine refuse is either stored in impoundments or co-disposed with the coarse refuse. The discharge water from the refuse material represents an environmental concern due to the potential release of trace elements, and the subsequent elevation of total dissolved solids and conductivity. The research findings reported in this dissertation addresses sustainable coal processing waste disposal through using strategies aimed at minimizing the environmental impacts. To …
Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee
Development Of Strategies To Minimize The Release Of Trace Elements From Coal Waste Sources, Mohammad Rezaee
Theses and Dissertations--Mining Engineering
To assess strategies aimed at minimizing the release of trace elements and the impact of disposal of coal waste materials on the environment, two long-term leaching experiments of up to five months duration were performed using waste materials from two plants cleaning high and low sulfur bituminous coal. The tests evaluated the mobility of major trace elements under different disposal scenarios: (i) a static leaching test designed to simulate the quiescent conditions encountered by coal waste material stored under water in a stable impoundment, and (ii) a dynamic test to simulate waste materials exposed to the atmosphere, either in variable …