Oceana Gold Waihi North Project Waihi North Project Geochemical Assessment – Geochemistry of Tailings and Overburden, Treatment and Mitigation Revision 9 – 17-Jun-2022 Prepared for – Oceana Gold (New Zealand) Limited – Co No.: 2274246 A-3 AECOM Multi Analysis Testing Favona & Martha Trace Elements Screened Previously Water Quality Compliance Limits Recommended detection limit (mg / kg) Strontium 1 Thorium 0.1 Tin 0.1 Silver Y 0.01 Thallium 0.1 Fluoride 1 Uranium 0.01 A1.2 Geochemical Testing The following analytical testing methods are used to characterise ore and rock samples from selected boreholes distributed across the proposed mining areas: • Multi-element analysis - whole rock testing for a range of trace and major elements to allow characterisation of the rock for potential contaminants that may leach and adversely influence water quality. • Static testing – whole rock testing for parameters indicative of the potential for acid generation. • Kinetic testing – accelerated weathering of select crushed rock samples to assess the rate of potential acidification and contaminant release. • Column testing – on site weathering of selected crushed rock samples exposed to atmospheric conditions and to assess management practices. Laboratory analyses for multi-element and static testing parameters were carried out by SGS Laboratories, with kinetic testing of selected rock samples carried out by AECOM. Column tests were conducted by OGNZL, on site at Waihi. Water analysis of samples from the kinetic and column tests was carried out by R J Hill Laboratories.
RkJQdWJsaXNoZXIy MjE2NDg3