Semester
Fall
Date of Graduation
2024
Document Type
Thesis
Degree Type
MS
College
Statler College of Engineering and Mineral Resources
Department
Civil and Environmental Engineering
Committee Chair
John Quaranta
Committee Member
Nathan DePriest
Committee Member
Leslie Hopkinson
Abstract
Abstract
Evaluation of Rare Earth Element Hydraulic Preconcentrate Material Characteristics and Instrumentation Design
Michael King
Manufacturing rare earth element (REE) hydraulic preconcentrate (HPC) by the West Virginia University Water Resources Institute (WRI) requires dewatering of high-water content low solids material. The HPC is hydraulically placed and stored in geotextile tubes with an incoming total solids of 2% and a desired passively dewatered solids content of 30%. The identification of the different material characteristics from two field HPC production sites is (one coal based and one hardrock based) required for identification. For the one coal based, the HPC material was tested and classified based on ASTM protocols. From these tests, the material was classified as a poorly graded sand (SP). Field observations indicated a high percentile of fines while also maintaining larger clumps due to metals contained within the material and polymer additives used for flocculation. For the hardrock site, the HPC material tested as a ML-silt and consolidation tests performed indicated that HPC elastic phase of consolidation is entirely absent as primary consolidation occurs immediately followed by a slow secondary consolidation phase. The coefficient of consolidation (cv) average values were determined to be 0.01628, 0.02827, and 0.03326 in2/min. These cv values coincide with previous research on acid mine drainage treatment precipitates.An instrumentation selection process undertaken with the objective to track the total solids developing within a Geobag under passive dewatering with volumetric change to determine an average timeframe to reach the 30% total solids target value. From tests and analysis conducted on different instruments, it was found that most conventional soil moisture probes are not adequate for use with the HPC sludge-like materials due to high volumetric reductions of the material during dewatering. Reliance on a manual field testing was implemented. The first Geobag experienced a decrease of 1 to 2% total solids over a three-month period. The Marcy Scale device showed a percent difference of 148.52% in its measurements compared to lab results for influent total solids. Differences are attributed to the influent’s low total solids content not being able to be precisely measured using the Marcy Scale device.
Recommended Citation
King, Michael Edward, "Evaluation of Rare Earth Element Hydraulic Preconcentrate Material Characteristics and Instrumentation Design" (2024). Graduate Theses, Dissertations, and Problem Reports. 12691.
https://researchrepository.wvu.edu/etd/12691
