POST-BETZE PIT LAKE WATER QUALITY PREDICTION, NEVADA

• DOI: 10.21000/jasmr06021863
• Publication Date: 2016-03-26T14:05:45Z
• Authors: William M. Schafer; Mark Logsdon; Guosheng Zhan; Ron Espell
• Keywords: 14. Life underwater; 01 natural sciences; 6. Clean water; 0105 earth and related environmental sciences

The Barrick Goldstrike Mine is located in the Carlin Trend, about 20 miles northwest of Carlin, Nevada.The majority ore mined at from Post-Betze open pit, largest pit operation Nevada.Nevada law requires that water quality temporary or permanent reservoirs may develop pits be periodically tested.Pit prediction conducted to monitor and possible impact it have on human, terrestrial, avian life.Water has been analyzed three previous studies (BGMI 1991, Radian-Baker 1997, TRC 2000).The most recent analysis lake model discussed this presentation.The effects placing 516 million t backfill waste rock into were also examined.This evaluation (Schafer Logsdon 2003) differs utilized laboratory where natural groundwater site was mixed with had contacted weathered mine as a means simulating geochemical reaction path.Calibration PHREEQC using batch test results enabled refinement solubility data obtained thermodynamic mineral equilibrium database employed by PHREEQC.The hydrology involved six key elements including 1) summarizing plan, geochemistry exposed rocks backfill, 2) evaluating filling regional flow model, 3) conducting eight large-diameter column generate representative contact waters, 4) performing mixing tests simulate final various stages filling, 5) calibrating based tests, 6) calibrated predict recharge.The uncalibrated accurately predicted common ion concentrations pH correctly simulated precipitation large amounts calcite when mixture meteoric evaporated (although aragonite actually dominant solid formed).Agreement between poorer for some metals, however.The over-predicted zinc, nickel antimony while under-predicting barium, copper arsenic.Calibration accurate trace element therefore improving its reliability prediction.