2011-03-14_REVISION - M1977493 (57)

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Permit Amendment (AM-06) - Climax Mine CM0000480 Lead and Copper Depressant Pre-mixed Nokes reagent will be incorporated into the mill circuit as a lead and copper depressant. Phosphorous pentasulfide is a principal ingredient in pre-mixed Nokes Reagent. Nokes Reagent is a mixture of caustic soda beads (NaOH) and phosphorous pentasulfide in solution with water. The addition of NaOH to the solution maintains a pH greater than 11 which prevents the release of hydrogen sulfide gas (1-12S). Climax uses only pre-mixed Nokes Reagent, which is liquid Nokes pre-mixed with NaOH prior to delivery. During past operations, Climax mixed Nokes Reagent at the mill site in a Nokes mixing tank inside the Nokes building. In the new mill, Nokes is planned to be stored in the Reagent Area of the Mill Building. Phosphorous pentasulfide is a reactive and ignitable greenish-yellow solid with a "rotten egg" smell which can affect the human body through inhalation, ingestion, and dermal contact. While solid phosphorous pentasulfide can cause dermal irritation, the primary health hazard associated with this material is the release of hydrogen sulfide gas upon contact with water. Hydrogen sulfide can be a primary health hazard which acts as an irritant to mucus membranes and can produce severe breathing difficulties. High concentrations can stop breathing immediately. Phosphorous pentasulfide, if released to the environment where it contacts water, will react by producing hydrogen sulfide gas and phosphoric acid. Both of these by-products can be injurious to aquatic and terrestrial biota. Phosphorous pentasulfide can be neutralized with an alkaline substance such as lime, NaOH, or soda ash. Flocculant GreatFloc 5500 is used as a flocculant to facilitate nucleation and settling of hydroxide precipitates. GreatFloc 5500 is a non-hazardous, common commercial flocculant used in the SDP. GreatFloc is an acrylamide polymer that may irritate the skin or eyes. Impermeable gloves and chemical splash goggles should be utilized when working with the chemical to prevent exposure. If the product is released to the environment, it should be contained with absorbent and removed. PH Adiustment for Hydroxide Precipitation of Metal Ions Calcium Oxide (CaO), also known as lime or quicklime, is used in the water treatment circuit at Climax to raise the pH and lower metal levels through precipitation. Lime also is used in reclamation operations and at the mill to adjust the pH of process water. Lime is stored at the Lime Station and on the current reclamation. Lime is a common, but strong caustic alkali. In high concentrations, lime can cause caustic irritation, inflammation, and burns through inhalation and dermal contact. Excessive amounts of lime in the environment can raise alkalinity to damaging levels. In aquatic systems, excessive lime also can cause potentially damaging precipitation/sedimentation. PH Adiustment to Meet Discharge Standards Sulfuric acid (H2SO4) is used to adjust the pH of treated water to within the permit stipulated range of pH 6.5 - 9.0 prior to discharge to Tenmile Creek. Sulfuric acid is a corrosive that can affect the human body through inhalation, ingestion, and dermal contact. Effects can vary from mild irritations to severe burns (internally or externally) depending upon the type, degree, and length of exposure. Repeated chronic exposure to dilute solutions may cause dermal irritations, whereas similar exposure to vapors or mists may cause erosion of teeth and inflammation of the eyes and mucus membranes of the nose, throat, and lungs. In the environment, sulfuric acid can be directly toxic through its corrosive nature or by lowering pH levels to the point of toxicity. In addition, even in very dilute forms, which may not be injurious to human health, chronic releases of sulfuric acid can dissolve metals from rocks which, in turn, can damage aquatic and, in some instances, terrestrial ecosystems. Sulfuric acid is readily neutralized by the addition of alkaline substances such as NaOH, CaO, or limestone. T-3.3 Material Safety Data Sheets for Designated Chemicals Current Material Safety Data Sheets (MSDS) are attached in Appendix T-A. Updated MSDSs are • Exhibit T T-8 May 2010