OCR

As a possible means of simplifying the loading-hauling setup and reducing the overall cost, Navajo also is experimenting with a self-loading scraper. The experimental unit consists of two Hancock 444 self-loading scrapers in tandem, powered by a LeTourneau-Westinghouse "B Speedpull" tractor. The two scrapers hold about 70 tons and make 14 to 16 round trips of over 8 miles each per shift. From Hopper to Crushers The trucks and self-loading scraper dump into a 400 ton hopper from where it goes to the primary and secondary crushers for reduction to minus 3/4 in. After crushing, the coal is delivered to two 35, 000 ton blending piles, which will be expanded to four to serve the third unit of the power plant. The coal is reclaimed from the blending piles, then passes across a belt scale and through a sampling tower in moving to the plant silos, capable of storing up to a 42 hour supply. Reclaiming and Blending Reclaiming and blending is done by the bucket-wheel reclaimer, operating end-on against the pile and taking the coal vertically from top to bottom, thus achieving a uniform mixture of the several layers and conse- quently a uniform BTU content. The blending facilities make it possible to deliver a relatively uniform product to the power plant, while at the same time allowing sufficient latitude in day-to-day mining for efficient low-cost Upon fine grinding to 70 per cent minus 200 mesh in ball mills, the pulverized coal is blown into the two boilers at the rate of 9p tons per hour. While the entire output of the Navajo Mine now serves as the fuel supply for the generation of electricity, the coal is also a potential source of hydro- carbons for the production of coal chemicals. Operating Staff Operating staff of the Navajo Mine, where Utah employs a total of 90 are A. F. Geiger, manager; James H. Olson, superintendent; Timothy Winterer, engineer; William Driscoll, engineer; Ray Bashioum, master mechanic; James Mainard, chief chemist, and E. J. Robinson, office manager. Navajos Cooperative Of great importance to both Utah and APS Co. is the co-operative attitude of the Navajo Tribe. The Tribe is trying to speed development of industry on the reservation in order to as sure expanding Navajo employment opportunities and to improve living standards. The Navajo Indian Reserva- tion consists of 16 million acres principally in Arizona with smaller portions in Colorado and Utah as well as New Mexico. The Reservation, equivalent In size to the combined areas of Maryland, Massachusetts and New Jersey, has a population of 93,000 Navajo Indians. During the past two and a half years, a large number of Navajos