Laserfiche WebLink
Mill tailings may be returned to the mine, amounting upto 100 tons/day, and transmitted down the Garland Shaft as <br />a water based slung via a 2" HDPE pipeline. Water from an onsite 10,000 gallon water storage tank will be used to <br />slurry the tailings. This water initially will be trucked in from a commercial water tap in Idaho Springs, owned by a <br />Venture Resources' affiliated company. <br />The tailings will then be impounded in their permanent storage place in the abandoned stopes within the mine. <br />These stope fill areas will be appropriately and properly designed and constructed to suit the specific mine <br />conditions and to insure the compact consolidation and secure containment of the slurry solids. The tailings solids <br />will settle quickly and compactly within the limited confines of these stope storage areas. Tailings storage areas are <br />isolated and they are located a minimum of thirty feet down-dip from the surface. <br />Intermediate sumps will be constructed within the stope fill areas to collect decanted/settled water. This water is <br />needed to be recycled so that new tailings can be slurried for the impoundment process to continue as described <br />previously. This recycling process involves a submersible electric pump that delivers the water via a 1 %4" HDPE <br />pipe back to the 10,000 gallon steel water tank located at the surface, to the northwest of the shaft opening, as shown <br />on Exhibit E. <br />Water consumed by the operation consists of losses due to evaporation and interstitial water in the porous spaces <br />between the grains of waste (which is impossible to remove due to capillary pressure). Water consumption is <br />estimated at 1,200 gallons per day by evaporation and capillary losses at a maximum production of 100 tons/day. <br />The quality of the water within the tailings, stope fill areas, and settled water sumps is controlled by the offsite, <br />gravity/flotation concentration milling process. This mill process removes the pyritic, acid producing materials from <br />the ore. Additionally, the process produces an alkaline (ph 7-9) tailings product that mitigates the possibility of acid <br />producing tailings. Representative process testing has been conducted to determine the waste stream <br />characterization of typical materials encountered within this type of mine. These are higher grade complex lead, <br />zinc, copper, gold, and silver ores and low-grade stope fill/pyritic waste material. Attached as Addenda A - H, are <br />typical waste characterizations of the complex lead, zinc, copper, gold and silver ores. Addendum I contains a <br />typical waste characterization of the low-grade stope fill/pyritic waste material. <br />Ambient ground water quality in the area is best inferred from the data collected from the Argo Tunnel Facility and <br />a monitoring well located at the Bald Eagle/ Two Brothers Mine. This information is attached as Addendum J. It <br />now must be noted that the water quality of the tailings process water exceeds the ambient ground water quality as <br />exhibited. Therefore, any seepage of water from this mine into the surrounding groundwater will not be a detriment <br />to groundwater quality. Furthermore, the compacted, finely ground solids will become a sealing medium; self- <br />sealing the stope fill areas against the percolation of water into the substrate rock. <br />This recycled water process will not contaminate, but will improve groundwater quality; and it will not create a <br />hazardous environment in the stope fill areas or in the rest of the mine. Due to the extreme depths of the mine <br />workings and stope fill areas, the most practical way to monitor water quality is to sample the recycled slurry <br />process water at the 10,000 gallon steel tank located on the surface. <br />We do not anticipate encountering any substantial groundwater during mining operations, due to the drainage of the <br />district through the Argo and Big 5 Tunnel networks. However, in the event substantial groundwater is encountered <br />mining operations will be ordered to cease. At that time, it will be evaluated whether the mining production <br />revenues will be able to offset water treatment plant costs so that operations can continue. If not, the mine will be <br />abandoned and the shaft sealed. If it looks feasible, a water treatment plant design will be submitted to the DRMS <br />for inclusion into this permit. <br />The only chemicals to be used are diesel fuel, motor oil, ATF and/or hydraulic oil, and automotive grease. Diesel <br />will be stored in a 55 gallon drum and/or 5 gallon fuel cans. Motor oil and ATF will be used in case quantities or a <br />maximum of 55 gallons each. A maximum of 2 cases of grease (12 tubes/case) will be on hand. All these <br />maintenance chemicals will be stored in the tool shed and/or hoist house. MSDS and hazard placards will be <br />displayed as required. <br />Mining operations are scheduled to terminate September 1, 2018.