2002-07-03_PERMIT FILE - M2002004

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Exhibit D conveyor belt transfers to maintain dust within regulated levels. Water for dust suppression on roadways • and in the removal of overburden will be applied by water truck, as required. Upon review of all potential impacts to people, structures, water wells, animals and the surrounding natural environment, Rio Grande has found no conditions that would prevent safe operation of the proposed mining and blasting operation at the site. Known domestic and livestock wells are deep, located approximately 450 feet below the Fort Hays Limestone unit in the Dakota Sandstone unit, with steel casing used through the unit to be mined. With the use of time delays and proper stemming of the blast holes, any dust, noise, and ground vibrations will not have long-term effects on the environment. It should be noted that there exists only one dwelling within one mile of proposed blasting and excavating. The geologic unit being mined is the Fort Hays Limestone, which occurs at a very shallow depth in the area to be permitted. Extensive core drilling activities have encountered no significant amounts of water within the surface rock to a depth of 100 feet. CEMENT MANUFACTURING The cement manufacturing facility will have a maximum production capacity of approximately one million tons per year of portland cement products and will incorporate state of the art processing technology. The primary raw material used in the manufacture of portland cement is limestone, which will be quarried on property leased from the State of Colorado. Quarried limestone will be processed through a crusher that will grind this material down to a five-inch size and smaller. After crushing, the limestone will be combined with other raw materials such as iron and alumina (an aluminum bearing mineral) and processed through a milling operation. The milling operation • will grind the raw materials into a fine powder in preparation for processing these materials through the preheater and kiln system. After milling, the raw materials will be processed through a five-stage preheater and calcining vessel. A preheater is designed to heat the raw materials using waste heat from hot combustion gases vented from the rotary kiln and calcining vessel. A calcining vessel is designed to further heat the raw materials to the point where calcination of the material is started. Calcination, where limestone is converted to lime, is the first of several material changes that occur within a kiln/calciner system during the manufacture of portland cement. Of the total fuel consumed in a kiln/calciner system, 60 percent is consumed in the calciner vessel. After preheating and calcining, the raw materials are introduced into the kiln. The rotary kiln will heat the raw materials to an ultimate temperature of around 2,800 OF. Additional heating of raw materials in the rotary kiln initiates a series of changes that result in the formation of clinker, which is an intermediate product. In physical appearance, the clinker looks roughly like walnut- sized nodules that are dark gray in color. Coal will be used as a source of fuel for supplying the necessary heat required in the rotary kiln to convert raw materials to clinker. Natural gas will be used as a back-up fuel. A coal stockpile will be maintained in an enclosed covered storage area. Clinker is discharged from the kiln at about 2,200 OF. This material needs to be cooled prior to the next processing step, which is achieved by passing the clinker through equipment known as a clinker cooler. The clinker cooler blows large volumes of air from under the clinker to quickly cool it. This serves two purposes: cooling the clinker in preparation for the next processing step and flash-freezing the desirable chemical and physical properties of this material. • The final step in the manufacture of portland cement is the addition of about 5 percent gypsum to the 1180-Mine Permit Exhibits (Jul.03.02)FINAL.doc D-8 July 3, 2002