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Page 2 of 3 <br />Once in place, the facility will utilize a jaw and cone 2-stage crushing circuit with a closed circuit <br />vibrating screen. The crushed ore will be mixed with soda-reagents (see below) and ground into slurry <br />using rod and ball mills that lead to a mineral concentrator. The overflow from both mills will pass over a <br />classifier (sieve bend), where the coarse sand will be re-run through the ball mill for further grinding and <br />the fines will be treated by flotation. No toxic or acidic reagents will be used in the grinding or flotation <br />processes. <br />The sequence, type, and quantity of reagents to be used is as follows: <br />• At the rod mill, 2-31bs of soda ash and <0.251bs of sodium silicate will be added for <br />each ton of crushed feed. <br />• At the flotation tailings box, a biodegradable surfactant (Dowfax) may be added as <br />needed. The flotation reagents to be used will be added at a conditioner following the <br />mineral concentrator tables. The flotation reagents to be used include a xanthate <br />(probably Aeroxanthate 350)(0.10-0.15 lbs/ton), dithioposphate (probably Aeroflot <br />208)(0.025-0.05 lbs/ton), and a froher (0.05-0.10 lbs/ton) which is a mixture of pine oil <br />(terpinol) and methyl butyl carbinol (MIBC). <br />• Soda ash is a dry reagent and will be stored in 50 lb bags and xanthate stored in large <br />drums. All of the reagents will be stored in separate shipping containers and liquid <br />reagents will have drip pans under the barrels of individual reagents. In the process <br />stream much of the soda ash will be recycled in solution as will some of the sodium <br />silicate and the surfactant. Storage tanks in the plant will consist of a recycle water tank <br />(169 cu. Ft.), the conditioner (50 cu. ft.), and the flotation machines (320 cu. ft.). <br />Tailings <br />Following the flotation circuit, saturated tailings will be pumped to a separate working area near the <br />disposal cavities (stopes), then put through a belt filter, a leaf filter, or a drum filter to achieve <15% <br />moisture content. The tailings sands will then be mixed with lime and portland cement and be placed as <br />stope backfill in large historic stopes which have the capacity to hold over 100,000 tons (>33,000 cu. <br />yds.). The water that is retained from filtration will be pumped back to the mill area and stored in 5,000 <br />gallon recycle-water tanks to be re-used for processing <br />SPLP leachate analyses have been completed on the two different rock types to be processed, and are <br />included in Attachment C. Following the processing of the ores, the residual tailings will be stripped of <br />most of the heavy metal constituents, and will not leach metals due to the addition of lime and cement. <br />These stabilizing additives will dramatically reduce permeability and exceed the long term geochemical <br />stability of the surrounding country rock. <br />Monitoring <br />The La Plata River is located 2,000 ft. down gradient from the May Day portal and is the only perennial <br />surface water feature near the site. The only groundwater emerging near the site is from the seep located <br />within the Idaho permit boundary. To ensure that the mining, processing, and tailings disposal are not <br />Technical Revision to the May Day Mine Permit, September 12, 2009.