Recycling of gold, iron, and bauxite mining tailings under the influence of electrokinetic remediation technique /
Abdul Wahab
- xxvii, 318 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Civil Engineering Technology
Thesis (Doctor of Philosophy in Civil Engineering) -- Universiti Malaysia Pahang Al Sultan Abdullah – 2025
Includes bibliographical references
This study examines the geotechnical and chemical properties of active and abandoned mine tailings, focusing on improving stability and removing heavy metals. In Malaysia, improper disposal of tailings, particularly from abandoned sites, causes soil and water contamination with toxic metals like Lead (Pb), Copper (Cu), Zinc (Zn), and Arsenic (As), posing significant risks to human health and the environment. The lack of effective remediation and the impact of industrialization and deforestation in mining areas further worsen contamination, highlighting the need to address the long-term effects of heavy metals on ecosystems. The electrokinetic stabilization technique (EKS) was applied to enhance shear strength, moisture control, and compaction, while the electrokinetic remediation technique (EKR) was practiced to remove the heavy metals from mining tailings. Tailing samples were sourced from gold, iron ore, and bauxite mines across Pahang, Malaysia. Two samples were taken from each tailing site using GPS for accurate location detection, and ArcGIS was used to map the sampling locations. The geotechnical parameters were analyzed for untreated tailings soil, and pre-elemental analysis, including ICP-OES, was conducted to assess heavy metal concentrations in the mining tailings soil. The EKR experiment was carried out in two phases. In phase I, a 100 V electric gradient was applied using stainless-steel electrodes for 4 hours. In Phase II, a voltage gradient of 150 V was constantly applied for 8 hours. After EKR treatment, elemental analysis and geotechnical assessments were performed on the samples to evaluate heavy metal removal efficiency and improved geotechnical properties. The moisture content was excellently improved, where 39.79%, 50.62% and 55.07% for TCI samples,73.04%, 75.33% and 83.76% for BII, 73.23%, 77.62% and 83.75% for SGM, and 31.11%, 32.21% and 41.59% for BGM samples. The shear strength was improved to 359.6 kPa for TCI tailings samples, 283 kPa for BII tailings samples, 365.8 kPa for SGM tailings samples, and 315.3 kPa for BGM tailings treated samples. An outstanding removal efficiency was observed for arsenic was 80.02% to 86.63%, copper, 67.7% to 92,74%, barium, 70.85% to 91.98%, magnesium, 78.7%, lead, 54.8% to 80.34%, and zinc, 77.87% to 80.54%. Elemental compositions before and after the EKR process were compared using Origin Pro 8.0 software. This research supports the UN Sustainable Development Goals by improving ecosystem health (SDG 3), enhancing water quality through tailings remediation (SDG 6), and promoting sustainable mining and infrastructure (SDGs 9 & 12). Cross-disciplinary collaboration is recommended to scale electrokinetic methods, optimize parameters, monitor treated tailings, and assess health and economic impacts.
THE0010161 (Local)
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