Abstract:

Every year, the Ta-Phoi copper processing plant disposes of about 970,000 tons of tailings with an Au grade content of approximately 0.1 g/t. In the operating technology, there has not yet been consideration for recovering useful components such as gold. The amount of gold lost annually in tailing products is about 116.4 kg Au. As of 2023, the amount of sludge is 3,531,682 tons (equivalent to 353.2 kg Au). The amount of tailings after the processing is significantly large, and the Au grade content in the tailings is still relatively high. The amount of tailings is currently stored at the tailing pond, if not treated, it will waste resources and cause a risk to environmental pollution. The article presents the results of research on the chemical composition and characteristics of tailings containing Au using sieve analysis, X-ray diffraction (XRD) analysis, inductively coupled plasma mass spectrometry/atomic emission spectrometry (ICP-MS/AES) analysis and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The research results provide a technological direction for Au recovery using gravity separation methods (spiral, shaking table, and jig), centrifugal gravity separation (Knelson, Falcon), and flotation method. To increase the processed Au content, the products should be thoroughly treated through the leaching method using suitable chemical lixiviants to meet the safety and environmental protection requirements, following regulations in Vietnam. This is the first time that there are comprehensive studies on the material composition of copper tailings for the purpose of recovering the tailings bearing gold. The study opens up prospects for the recovery of useful minerals in the tailings of copper beneficiation plants, in particular and the tailings of the mineral processing plants in general.