Potential utilization of artisanal gold-mine tailings as geopolymeric source material: preliminary investigation

Abstract

In this study, chemical and mineralogical characterizations of gold-mine tailings in key mining areas in Mindanao, Philippines were investigated for possible utilization as geopolymeric source material. Results of X-ray fluorescence (XRF) and energy dispersive X-ray spectroscopy (EDS) showed that the mine tailings samples have significant amounts of silicon, aluminum and calcium, which are crucial elements needed for geopolymerization. This was confirmed by the IR spectroscopic and mineralogical characteristics of the tailings where vibration bonds and minerals associated with Al and Si such as kaolinite and zeolite are detected. These minerals are already established as indicators for a material to be a good feedstock for geopolymerization. Furthermore, one of the tailings samples had an Si/Al ratio of 4.81, which was close to the recommended value of 3.0 for geopolymerization. The compressive strength of the synthesized geopolymer bricks gained an average of 5.48 MPa. The results suggested that gold mine tailings from key mining areas in Mindanao, Philippines could be used as geopolymer source material.

Solid-phase partitioning and release-retention mechanisms of copper, lead, zinc and arsenic in soils impacted by artisanal and small-scale gold mining (ASGM) activities

“…More recently, ASGM operators in prominent Au mining districts in the Philippines are using a two-step approach to recover more Au from the ores. In the first step, the ores are crushed and Au is recovered via conventional gravity separation-amalgamation while in the second step, tailings from the first step are ground in make-shift ball mills and then fed to an improvised carbon-in-pulp (CIP) circuit ( Aseniero et al., 2019 ; Veiga et al., 2014 ). The final tailings after CIP are then disposed of in shallow ‘pits’ close to the processing plant, which readily overflows during the wet season ( Opiso et al., 2018 ).…”

Optimization of the Mix Formulation of Geopolymer using Nickel-laterite Mine Waste and Coal Fly Ash

“…Pre-treatment of NMW by thermal activation was performed first before experimental runs were conducted [7]. NMW samples were heat treated in the laboratory furnace at a ramping rate of 10 °C per minute to attain a temperature of 700 °C at a holding time of 2 hours.…”

Improved pyrolysis behavior of ammonium polyphosphate-melamine-expandable (APP-MEL-EG) intumescent fire retardant coating system using ceria and dolomite as additives for I-beam steel application

“…In this study, a novel and more effective IFR coating using inorganic additives is proposed and its thermal protection performance on an Ibeam steel substrate was evaluated. Ceria and dolomite were selected because the former is a known waste from glassmaking industries (Tabelin et al, 2013(Tabelin et al, , 2018 while the latter is ubiquitous in limestone quarries (Eang et al, 2018a, b), sediments (Huyen et al, 2019a, b;Mar et al, 2013), waste rocks (Tabelin et al, 2012a, b;, 2017a and tailings of many gold mines (Aseniero et al, 2019;Opiso et al, 2018;Park et al, 2019). In addition to their beneficial use in the construction industry, finding value in these waste materials would also be good to the environment as a result of waste reduction for disposal from the glassmaking and mining industries.…”