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By E. V. Howard

During the recent expansion of precipitate copper production at the Chino Mines Division of Kennecott Copper Corp., Santa Rita, N. Mex., local studies of the dump leaching process were intensified. As these studies progressed, it became apparent that a reliable method for locating leach solutions within the dump was required, since the contact between the leach solutions and the copper-bearing ma.teria1 determines recovery. In the past, the problem of determining leach solution contact has been attacked by various methods, including destructive testing (dump dissection), indirect observation (such as chloride or dye tracers) and mathematical or laboratory model studies, but they have not proved completely satisfactory. The investigation of methods for in situ observation of leach solutions led to consideration of radiation logging in drillholes, which are subsurface techniques used in petroleum exploration and development for locating fluids and measuring porosity. A significant advantage of radiation logging is that, unlike other types of logging, measurements may be made in cased holes, since gamma rays and neutrons will penetrate steel and cement. Three techniques are currently used at Chino: Natural gamma ray logging; neutron-neutron, or moisture logging; and gamma-gamma, or bulk density logging.

Jan 4, 1968

By L. B. Beneitone

Over the years, the rope changing procedure on the two double-drum San Manuel ore hoists has been streamlined and improved, so that a job that once required eight hours to complete is now finished in four. The ropes, constructed of improved plow steel, 6 x 25 filler wire, pre-formed, right lay, Lang lay with a fiber core and weighing 8 ½ lb per ft, have a 2 ¼ in. diam and are 3200 ft long. They have widely varying lives, but on the average a rope change on one of the two hoists is required every six months. When a rope change becomes necessary, the ropes on both drums of a hoist are replaced. Thorough planning and preparation are essential for efficient rope changes. A briefing session is held on the day prior to the change, during which the entire procedure is reviewed on a blackboard and discussed among the cable rigging crew. These discussions have led to many improvements that have been incorporated into the present rope changing procedure.

Jan 4, 1968

By Francis Cameron

Mining is both exciting and rewarding-although at times somewhat frustrating-and we all can have real pride in our industry, in its people, and in its accomplishments. It is, however, with concern that I have noted a deterioration in this Country in what might be called mining's stature and in the growth of a belief in many quarters that our mineral reserves are rapidly approaching exhaustion. In other words, there is a popular image that we are fast becoming a "have not" nation in many respects and that the domestic mining industry can no longer be considered, in the vernacular of Wall Street, to offer much in the way of "growth potential." I do not subscribe to this hypothesis, nor do I believe that the record of the mining industry bears this out. However, let me add that we can, in time, talk ourselves into this frame of mind and we can hasten the day when this very well might come about by unnecessary and unwise legislation or regulation. My remarks today are basically designed to give my reasons for refuting this negative philosophy and to review our record. With your help, I know we can improve our image, and the public's recognition of our industry's peculiar problems.

Jan 4, 1968

The new, internationally-owned Savage River Mines iron ore mining, concentrating and pelletizing project, built and operated by Pickands Mather & Co. International, was dedicated March 6 at Port Latta, Tasmania, Australia. Construction of the $79 million project began in 1965 and involved an open pit mine and concentrating plant plus a complete town for about 350 employees at Savage River; a 53-mile pipeline to transport the concentrates; a pelletizing plant and shipping facilities at Port Latta, which is on Bass Strait separating Tasmania from the Australian mainland. The project has a rated capacity of 2.25 million Ltpy of high-grade magnetite pellets, which will be sold to five Japanese steel companies under 20-year contracts. The open pit mine is located in the central portion of the Savage River deposits. Mining equipment, capable of moving 10 million tpy of ore and overburden, consists of four 6-cu yd electric shovels and 12 50-ton trucks. The concentrating plant, with a design capacity of 5 million tpy of ore, will use magnetic separators to upgrade the ore, which averages 38% iron, to a concentrate averaging 67% iron.

Jan 4, 1968

By E. Alan Haley

Accurate and economic control of line and grade on long tunnels, large structures, excavations and waterways has been a problem to surveyors and engineers for decades. The conventional method of surveying, incorporating a level, transit and a number of surveying technicians, has proven to be a very expensive and time-consuming operation. Now, however, engineers have adapted the laser to help ease the problems of surveying, at the same time increasing the efficiency of such operations. The laser, which projects a continuous, narrow red beam of brilliant light, provides a constant alignment reference that does not interfere with personnel or equipment. A complete laser alignment system, specifically designed for and suited to a variety of mining and tunneling operations, has been developed by the Perkin-Elmer Corp. The engineering significance of this development can be fully realized when it is noted that, aside from potentially tremendous economic advantages in terms of labor savings, the laser beam provides a system of alignment that is at least ten times more accurate than presently used optical systems. The new laser system provides accuracies within 10 microinches per foot (1 x 10-5in.) when used with an accessory centering detector. In one of its first field trials, the laser was used for alignment of a two-mile tunnel which showed a total deviation of less than 5/8 in.

Jan 4, 1968

By E. P. Pfleider, O. Rellensmann

In the May 1959 issue of [=] the authors reported on the gyrotheodolite as used for determining azimuths in surface and underground work. Further research has led to the development of a new type of gyro instrument, the band-suspended gyro attachment, which is essentially an upset gyro attached to the top of a theodolite. The new gyro attachment is light enough to be mounted on any angle-measuring instrument if the design of the telescope standard permits. Gyrotheodolite units have been used to transfer meridian lines underground in the Coeur d'Alene mining district, although they have not been used extensively in the U.S. In other parts of the world, however, they have been adopted as the standard surveying instrument by mining engineers.

Jan 3, 1968

By Nicholas Chlumecky

To date information is somewhat limited concerning the strength and bearing capacity of floor strata, which is of great importance where proper roof control is desired. If the bearing strength of strata is not known, the support may be excessively strong in relation to the support capacity of the floor, with the result that strong props sink into the floor strata, giving them dubious value as a roof support. The method described is used to determine how tests are made on dry rock to determine the required support area for the base of props or other structures which may rest on rock strata in mines. Relationships were established for the bearing capacity of rocks which were subjected to loads by means of bearing areas of various sizes ranging from 0.09 sq cm (.014 sq in.) to 700 sq cm (108.5 sq in.). This permits the evaluation of the bearing capacity of rocks by testing small areas for the de- termination of the capacity of larger areas.

Jan 3, 1968

By D. W. Schmidt, J. W. Shuster

Use of electric-wheel-driven haulage trucks at Chino dates back to 1963, and in today's fleet of 38 units, 17 trucks are electric-wheel- type powered with 700 hp diesel engines. Output of these engines is not adequate to exploit fully the 1200 hp potential of the two electric- wheel-drive motors, and, as a result, Chino has been testing larger prime power sources. An earlier test involved the use and evaluation of 1000 hp gas turbine engine in a conventional Model M-100 Unit Rig haulage truck (see [ ], May 1967, pp. 57-60). Now Chino has tested a trolley-diesel application in the same 100-ton capacity vehicle, and has shown that trolley power on electric-wheel-drive trucks can improve productivity rates from 18-36% on adverse grades, depending, of course, upon haul road profiles.

Jan 3, 1968

Western Mining Corp. has announced plans to expand its mining operations at Kambalda, and to build a nickel refinery at Kwinana, near Perth, Western Australia. The refinery will use the ammonia-leach hydrogen reduction processes of Sherritt Gordon Mines Ltd., and it is expected that by 1970, when the expansion is scheduled for completion, Western will be the world's fourth largest nickel producer. Although estimates have not been finalized, the total cost is expected to be about $55 million. The mine and mill facilities at Kambalda, which began production in June 1967, are now producing at the rate of 11 million lb of contained nickel per year. The company estimates the sulfide ore reserves at Kambalda and St. Ives at 10.4 million tons averaging an usually high grade of 3.8% nickel, or about 790 million lb of contained nickel. In addition, silicate and oxidized ores have been located in both areas.

Jan 3, 1968

By Lawrence P. Bonicatto

The steel industry's increased demand for higher grade pellets has caused the pellet producers to investigate methods of upgrading their product and the Hanna Mining Co.'s Groveland plant on the Upper Peninsula of Michigan is no exception. The low grade iron deposit is a complex mixture of magnetite and hematite with chert, quartz, jasper and various iron silicates.1 Beneficiation is by Humphrey spirals and anionic flotation of the iron minerals.2 Flotation of the spiral tailings makes up about 75% of the concentrate, while a minor amount of concentrate (less than 3%) is produced in magnetic circuits. The concentrate is pelletized at the rate of 1.6 million tpy. The initial concentrating facilities were constructed in 1958 and the concentrate was marketed as sinter feed until a pelletizing plant was added early in 1963. Grade improvement soon became a high priority research project, and several methods of concentration were investigated.

Jan 3, 1968

By R. S. McClellan

Western Talc Company, Inc., with headquarters in Los Angeles, Calif., has just completed an extensive modernization and expansion program at its talc mine near Tecopa, Calif., and at its talc and clay mills at Dunn Siding, Calif., the nearest rail shipping point to the mine. The basic objective of the program was to provide facilities necessary to produce 300 tpd of a wide range of ground talc and clay grades for the ceramic, paint, paper, rubber and other industries. In the planning of the program every effort was made to provide a system which would permit a high degree of quality control and uniformity of the finished products, along with efficient operation. Several years ago, R. T. Vanderbilt Co., Inc. purchased Western Talc Co. after a comprehensive investigation of its properties, including an extensive diamond drilling campaign. Western Talc's properties embraced a number of claims in the Resting Springs mining district in the northern part of San Bernardino Co. and the southern part of Inyo Co., Calif., some seven miles southeast of the town of Tecopa. Operations by the original company were started on a small scale in 1913 and production from that date to the time of purchase of the company by Vanderbilt is estimated at 250,000 tons. The major part of this output was sold to the ceramic wall tile industry.

Jan 3, 1968

By E. D. Fields, M. C. Tippett, S. W. Sayers

The Copper Canyon and Copper Basin properties of Duval Corp., in Lander Co., have been recently added to the list of porphyry copper mines in Nevada, marking the first new copper open pit operations in this state in 15 years. Ore is processed in the 4000 tpd flotation mill at Copper Canyon, with some copper being recovered by dump leaching. The ore from Copper Basin, 10 miles northeast of the Canyon, is trucked to the mill for concentration. Cost of developing the properties is estimated at $22 million. It was recognized at an early stage of exploration that the two deposits were quite different. Continuity, mineralogy and grade of ore are much more uniform in the Canyon than in the higher grade, pod-like deposits in the Basin. The fundamental difference between the two areas is that the Canyon mineralization is dominantly hypogene, whereas the Basin ores are secondarily enriched.

Jan 3, 1968

By John L. Schroder

The demands for increased productivity on the 1967 coal industry have generated new operating trends and fresh approaches to old methods, which have enabled the industry to keep pace with the expanding economy. Changes, while not radical in concept or design, have been plentiful and are marked by the refinement of the already tried, tested and proven. Perhaps not since World War II have there been demands on equipment manufacturers to design and deliver such diversified types of machines as those required by the industry in the past year. Equipment developments-following a plan which calls for higher productivity, lower maintenance costs and greater machine availability- have tended more toward increased horsepower and heavier, more rugged equipment. Electrical and mechanical components, designed in many instances with maximum reliability rather than initial costs as the main criterion, have contributed to the improvements in over-all performance. High-strength, specialty steels are finding use in a wide range of equipment applications. The horsepower capacity of electric motors being installed is more frequently being rated on a continuous basis rather than the former one hr or less and, as a result, fewer failures now occur because of overloading. These developments reflect the pyramiding cost of equipment down-time and represent definitive progress in reducing the magnitude of the problem.

Jan 2, 1968

By S. W. Hazen

The use of operations research and computer techniques continued to expand during 1967. A number of mining companies either obtained computers or were experimenting with their use through service bureaus. This trend was also evident in the Canadian mining industry. Although the annual Symposium and Short Course on Computers and Operations Research in Mineral Industries was not held in 1967, technical periodicals like MINING ENGINEERING, Mining Congress Journal and Engineering and Mining Journal stepped up their coverage on the subject. The annual AIME meeting had eight papers in two sessions and one session on Operations Research was held at the SME Fall Meeting in Las Vegas.

Jan 2, 1968

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Jan 2, 1968

By J. J. Scott

During 1967 wage settlements and strikes ran at a high rate and it has been estimated that union gains of 4 ½ % to 5% per year have been attained in many instances. When these events are coupled with the need to operate on lower grade and deeper deposits the need for technological advances in underground mining becomes obvious. Emphasis has been on ways to reduce the number of manshifts required per ton of product. Most significant advances have been made in rapid advance of primary mine openings, development of mobile, rubber-tired, front-end loaders and hauling units, high-speed drilling with rotary and rotary percussive units and a serious look at nuclear devices to break large volumes of ore cheaply. Boring Developments in bit manufacture and metallurgy have allowed continuous boring-type machines to be used on harder formations than was deemed feasible in the past. Hecla Mining Co. has been using raise boring equipment for drilling 9 7/8 in. diam pilot holes in raises which are later reamed in an upward direction to 48 in. diam. The machine used is a J. S. Robbins model 42R raise borer which has been used successfully to drill two relatively long 48-in. diam holes. The first was 520 ft in length at a dip of 76º, and the second was a 785-ft vertical hole.

Jan 2, 1968

By T. Carl Shelton

The coal industry of the United States in 1967 had reasons to be both exuberant and concerned about its present and future role in the economy of the country. Continuing a momentum that began in the early 1960's, the industry has moved ahead in providing competitive customized products to strengthen its long-term domestic and foreign commitments, and has maintained with steady progress its position as a major supplier of energy. On the other hand, the industry must overcome air- water pollution and conservation-reclamation problems that have been identified by 1967 legislation. Throughout the year, the industry was characterized as "progressive," "healthy" and "dynamic." To have been termed a "growth industry" in 1967, is an accolade the coal industry can accept with pride. Culminating its efforts throughout the decade, the industry has emerged with a competitive image that is representative of its future strength.

Jan 2, 1968

By P. D. Proctor, M. P. Nackowski

Quantification in recording geologic phenomena and application of well-known geologic principles to engineering works continued at an increasing rate during the year. Highway departments, water resources agencies, private firms and governmental agencies involved in tunnel excavations, dam site locations and construction, consultants and government experts in subsurface liquid-waste disposal, designers of underground storage facilities and city and regional planners all confirmed greater use of applied geology in their planning and implementation of plans. Applications of quantified geologic data to highway locations, slope control of cuts, raw material sources, water sources and water run- off showed a striking increase in number. Environmental geology and geologic hazards became part of the jargon of the geologic profession, and the American public began to realize more fully the significance of where they live, and on what and near what geologic phenomena which might effect their well-being. Tunnel work for water projects of almost dream-like magnitude kept geologic engineers busily engaged in predicting and testing local geologic conditions for construction projects. Disposal of industrial and radioactive liquid wastes continued as problems, but use of stratigraphic data, fluid flow rates and direction of flow helped solve some critical waste disposal problems. Unusual applications of seismic networks, remote sensing methods and X-ray techniques in geological engineering applications added other tools to this increasingly important profession.

Jan 2, 1968

By Chester N. Truax

Still another shadow was cast over coal's largest market-the electric utilities-when President Johnson signed into law the Federal Clean Air Act of 1967. Air pollution-sulfur reduction-was thus brought into sharper focus as one of the central problems of the coal industry. Industry executives testified in both Houses of Congress to enable the lawmakers to develop a workable and economic law. The new legislation calls for the Secretary of Health, Education and Welfare to establish air control regions. After the regions are outlined the Department will publish air quality criteria on pollutants. Anticipating this legislation, the coal and utility industries have for the last several years been involved in extensive research programs to develop solutions to the air pollution problem. Even though the coal industry has been under strong attack for its part in adding contaminants to the atmosphere, it is by no means the major contributor.

Jan 2, 1968

By J. W. Eckerd

Anthracite mining developments have not been as spectacular as the advances made for bituminous coal. The reasons are well known, i.e., steeply pitching seams of the western, eastern, middle and southern fields, and the physical conditions of the strata in which the seams are situated. Beds with moderate pitches (30º to 35º or less) have been mined with coal planers, longwall with movable props, shaker chutes, coal borers and large diameter boring machines. However, the use of this equipment has been limited to a relatively small portion of the production. Long-hole drilling has been developed from a point where holes of 25 or 30 ft have been replaced by those up to 130 ft. This has been possible through the introduction of primacord and similar detonating agents that can fire a long train of explosives with one cap. The usual practice in long-hole mining is to drive a gangway, chutes and monkey heading, or return airway, in the normal development manner. Two breasts can then be driven from the lower to the upper level to act as openings for the beginning of the long-hole work. Following completion of the development, holes can then be drilled from the monkey headings 100 ft or more up the pitch through the coal to within 15 ft or more of the upper level, depending on the nature of the coal on the roof. The thickness of the coal bed determines the spacing of the long holes, although they usually are on 6-ft centers for a 6-ft thick coal seam. The Bureau of Mines has conducted extensive investigations and tests on the development of a hydraulic mining system to be used in conjunction with hydraulic hoisting. Tests were conducted in cooperation with a large anthracite producer in a coal seam from 10 ft 6 in. to 15 ft in thickness and on a pitch from 0º to 20. This particular mining procedure is adaptable only to thick seams on relatively flat pitch as the maneuverability of the hydraulic jumbo is an important restricting factor.

Jan 2, 1968