Feasibility Study and Technical Report - Pretivm

• vendors’ instrumentation packages• gold room operations.An automatic sampling system will collect samples from selected product streams fordaily metallurgical accounting and operation optimization.Particle size-based computer control systems will be used to maintain the optimum grindsizes for the primary grinding and rougher/scavenger concentrate regrinding circuits.Particle size analyzers will provide the main inputs to the control system.Online Sample AnalysisThe plant will rely on the on-stream or in-stream particle size analyzer and variousflowrate and solid density meters for process control. The analyzer and meters willanalyze the various slurry streams in the circuit. The on-stream particle size monitor willdetermine the particle sizes of the hydrocyclone overflows in the primary grinding circuitand regrinding circuit. A sufficient number of samples will be taken in order to controlhydrocyclone overflow particle size and optimize the grinding circuit operations. Specificsamples that will be taken for metallurgical accounting purposes include the flotationfeed to the circuit, the final tailings, the final concentrate sample, and occasionally themiddling products. These samples will be collected on a shift-basis and will be assayedin the assay laboratory.Remote MonitoringCCTV cameras will be installed at various locations throughout the plant, including theprimary crushing facility, the conveyor discharge point, the SAG mill surge feed conveyer,the SAG and ball mill grinding area, the flotation area, the regrind area, the paste plant,the gold room, the concentrate handling building, and the tailings handling facilities. Thecameras will be monitored from the plant control room. Fuel storage facilities will beremotely monitored by level controls and CCTV cameras.17.2 ANNUAL PRODUCTION ESTIMATEThe process plant will generate two products: gold-silver doré and gold-silver bearingconcentrate. The annual metal production shown in Table 17.2 has been projectedbased on the mining production plan outlined in Section 16.0 and the metallurgicalperformance outlined in Section 13.0. Based on the LOM annual average, the processplant is estimated to produce approximately 4,300 kg of gold and 1,500 kg of silvercontained in doré, and 42,000 t of gold-silver bearing flotation concentrate. On average,the flotation concentrate will contain approximately 135 g/t gold and 1,028 g/t silver.The arsenic content of the flotation concentrates to be shipped to the smelter(s) isexpected to be marginally higher than the penalty thresholds outlined by most smeltersand will require further review.Pretium Resources Inc. 17-17 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC