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1 <br /> <br />1 <br /> <br /> <br />1 <br /> <br />1 <br />1 <br />1 <br />1 <br />1 <br /> <br /> <br />1 <br /> <br />1 <br />1 <br />1 <br /> <br />The description of each of the aforementioned unit operations is presented in the following <br />paragraphs. Note that the final configuration may differ from the following descriptions because <br />a basic component of field installation includes optimization of the water treatment system, <br />which may result in slight modifications to the system configuration. <br />Pretreatment Stage - T7tis component of the operation will consist of a reagent hopper, and a <br />reagent feeder in combination with a continuously mixed reaction tank. Sodium h~rdroxide in the <br />form of a liquid will be fed at a controlled rate into the reaction tank. Due to the required process <br />water flow rate and consumption of alkaline reagent, the sodium hydroxide hopper will be <br />required to hold a minimum of 500 gallons of solution. The reaction taril: will require <br />approximately aten-minute residence time and as such will have a volume requirement of 5,000 <br />gallons. The pH of the process water will be raised to a value between 9.5 and 10 0 while in the <br />reaction tank. This rise in pH will facilitate the hydrolysis and production of insoluble hydroxide <br />products from the vast majority of the manganese, and other constituents contained in the process <br />water. As the process water does not contain large quantities of aluminum, the pH may be raised <br />in one step rather than two. The pH of the solution will be lowered to a value of approximately <br />8.0 prior to entering the nanofiltration stage of the process by the addition of minimum quantities <br />of hydrochloric acid. Addition of anti-scalent reagents to this process stream will be completed <br />prior to the stream passing through apre-membrane sepazation microfiltration lnocess. This <br />microfiltration process will ensure that precipitates formed during the pretreatment stage do not <br />affect the nanofiltration membranes. <br />Nanofiltratioo Stage- The function of this unit operation is to separate the incom.ng water into <br />two streams. This separation occurs by the use of a nanofiltration membrane. The membrane <br />contains pore openings of a specific size, through which only specific quantities of dissolved ions <br />will pass dependent upon specific process pazameters including pressure. Th; first of the <br />aforementioned streams (known as "permeate") represents the treated water with c oncentrations <br />of constituents reduced to levels that meet the discharge standards, which will be set in the <br />applicable regulatory authorizations. The second of the process streams (known as the <br />concentrate) emanating from the nanofiltration unit will contain the dissolved aid suspended <br />materials removed from the permeate solution. The ratio of the quantities o1 permeate to <br />Barrie Mountain Resources, /nc. 5/tepherd Miller, /nc. <br />i~,rnb.a+Kiroala~~inbzm.a,,,..,i~rtwd•,•p~T~s~~e/dam 5 September l7, /999 <br />