Laserfiche WebLink
Newmont Mining Corporation <br /> PO NEWMONT 100No � <br /> h0� nh: St <br /> / !� ! Victor Colorado 80860 <br /> /�,1(---) ! IT(I f-1lVlFrl/l_.f 17757762525 <br /> F 775 778 2513 <br /> www newmont con, <br /> Memo EG 18-14 <br /> .. Wednesday September 19th,2018 <br /> Charles Bissue <br /> B. Scholz, L. Colby, J. Schley, J. Dehlin <br /> Jofree Duran <br /> . - Lime Mixing Tank and Solution Sump Location Geotechnical Evaluation <br /> This document summarizes the geotechnical evaluation of the proposed location for the Lime Mixing Tank <br /> and the Solution Sump for the Arequa Gulch Phase II Solution Flow Modification. <br /> Pending DRMS approval, the proposed lime mixing tank and the solution sump will be located on a flat <br /> platform at approximately 9500 ft elevation. This platform is located between 140 and 200 ft above plastic <br /> liner. <br /> The sump is planned to be constructed within the leached ore to a maximum depth of 2 ft, and ripped to <br /> allow percolation of the solution through the VLF and into the Phase I caissons. The stacked ore in this area <br /> of the VLF-1 consistes of crushed rock 1 '/2-minus. <br /> As part of the design of the VLF-1, percolation tests were conducted for the crusher ore at different loads to <br /> a maximum rate of 0.045 gpm/sf with no ponding water(AMEC, 2011). <br /> The sump will have an approximate area of 3,000 sf and the operational flow will be between 800 to 2500 <br /> gpm.This requires a percolation rate between 0.27 to 0.838 gpm/sf at the footprint of the sump. It is <br /> expected that the footprint of the percolating solution should grow in depth and the percolation rates should <br /> diminish drastically. <br /> In order to mitigate any potential overflow of solution it is recommended to: <br /> - Start this process at low flows until it can be determined the operational flow that the proposed sump can <br /> percolate without overtopping. <br /> - Construct a secondary sump of a similar size where the solution from the main sump could overflow.This <br /> secondary sump should not receive any solution as should only work as a contingency sump. <br /> - In the event of any overflow to the secondary sump,this process should stop until a revised plan is in <br /> place. <br /> - This area needs to be inspected regularly to make sure that is working as per design. <br /> Page 1 of 2 <br />