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By Carl E. Reistle

ENGINEERS as a group are often criticized because they have been responsible for the development of many technical improvements only to allow the administration of them to pass into the hands of others who may have little understanding of how they operate and little competence in their use. These criticisms are not always justified. There are many engineers who have shown themselves to be great administrators in addition to being great creators or builders, and more and more one sees the engineer demonstrating unusual administrative ability as he moves into the executive ranks. The last five or ten years have seen a new movement developing in this country-a movement brought about through the recognition by business statesmen that successful business administrators and executives just cannot be expected to develop like Topsy, that the management of a company must deliberately take steps to cultivate the proper climate or environment for growth if it wishes to provide an adequate and capable succession of executives in the future. This movement has taken on a number of names-Management Development, Executive Development, Personnel Development-but are these not actually misnomers? Can we develop anybody? In the strictest sense of the word, the author doubts that anyone can change any other person, at least, not much. The change must come from within. Perhaps this movement should be looked at not as a program of developing people but as one of giving people an opportunity to develop themselves. In the Humble Oil & Refining Co. there is an Executive Development Program; maybe it might better be called a Program of Development for Executives.

Jan 8, 1954

By George B. Clark

THE geological data emphasized so successfully in prospecting for new deposits, that is, structural controls, strength of solutions, and type of mineralization, are basically those required for successful exploitation. In the mining of newly discovered deposits the most economical methods should be employed as early as possible to keep the overall cost per unit produced at a minimum and to permit maximum extraction of valuable minerals. A crucial question is: How can geological data be translated into useful quantitative results which will aid in achieving this end? H. E. McKinistry1 has suggested that a solution may be reached in one of two ways: 1-the usual approach, use of judgment based on experience; or 2-mathematical calculations and tests on models, both subject to certain limitations. He also suggests that in addition to better use of geology more case data and theoretical data are needed on which to base sound judgment. Further research, therefore, is necessary. Perhaps in this field the emphasis should be on more specialization in mining methods and ground movement by men with thorough training in physics, engineering, geology, and underground mining. These specialists would be equipped to point out the most economical and scientific methods of exploitation.

Jan 8, 1954

By Benny Langston, Frank M. Jr. Stephens

IN recent years much attention has been given to recovery, treatment, and disposal of dusts discharged into the atmosphere from operations of industry. Considerable data has been accumulated on both operational1-4 and design5,6 of dust-collector equipment for commercial installations. On the other hand, there is almost no published data on design and construction of small-scale equipment to handle dust problems that arise in the ore-dressing laboratory. Dust-collection equipment such as multiclones, single-cyclones, scrubbers, chemical and mechanical filters, settling chambers, and electrostatic separators has proved its efficiency for collecting dust in industry. In the laboratory, however, the engineer is faced with the problem of collecting small quantities of dust, inexpensively, without diverting the major effort from the metallurgical problem to the problem of collecting dust produced by the process.

Jan 8, 1954

By Charles W. Merrill

WHETHER the valuable components in a mineral deposit can be mined and separated from the worthless matrix, processed, and marketed depends not only upon the natural factors and the physical and chemical techniques, but also upon many extrinsic factors relevant to the economics of the business of exploring, developing, and producing minerals. To meet a need for proper coverage of this specialized field of economics, the Mineral Economics Div. of the AIME has developed a plan for assembling a volume setting forth important factors affecting mineral enterprises other than those that lend themselves to solution through science or technology. The program has been considered by the Institute's Directors and they have approved it, subject to a decision of the Mineral Economics Div. to carry it out.*

Jan 8, 1954

VARYING in thickness and in number from place to place, coal seams in the Canadian Rockies also range in pitch from nearly horizontal to vertical, sometimes with overturns. Over the entire coal-bearing area there are considerable differences of rank in coals of the same geological age, and there are marked differences in ash content and washability characteristics. Correlation of seams at mining operations within a few miles of each other has often proved impossible. These factors influence mining methods, and, of course, production results. The oldest coal formations of western Canada are of Lower Cretaceous age, as the carboniferous sediments are marine and contain no coal. Coal is also present in formations of Upper Cretaceous and Tertiary ages. The rank of coal varies from semianthracite in some operations in the Kootenay and Luscar formations of the Lower Cretaceous in the Rockies to lignite in the Tertiary fields of the Saskatchewan prairies. Fig. 1 shows the general extent of the formations.

Jan 8, 1954

By Parke A. Hodges

CHROMIUM, one of the most vital of the strategic metals, has constantly increasing importance as research expands potential uses in alloy steel metallurgy. All signs point to a steadily growing use for chrome ore, and the general subject has received a great deal of attention recently.1 A relatively little known country, Southern Rhodesia produced a total of 5.949 million tons, or 18.6 pct of the total world chrome output, between 1906 and 1950, according to figures from the U. S. Dept. of Commerce. According to U. S. Bureau of Mines figures, Southern Rhodesia produced 291,525 tons in 1950 and 300,267 tons in 1951, or approximately 13 and 11 pct, respectively, of world production for the two years. In 1953 the Rhodesian Vanadium Corp. produced about 85,000 tons of which probably 7,000 tons were concentrate. Production by other companies was high. Large in themselves, the figures assume even greater significance because most of this output is of metallurgical grade.

Jan 8, 1954

By E. B. Burwell, R. H. Nesbitt

A NEW milestone in the progress of photography and subsurface exploration was reached when the Chief of Army Engineers announced the development of the NX borehole camera. In obtaining continuous undistorted cylindrical color pictures of dry or water-filled borings the device surpasses all other cameras designed for photographing interior surfaces of pipes, wells, and conduits. The usefulness of the camera and the unique projector that comes with it are at once apparent. To the geological, mining, and civil engineer alike it signifies the end of guesswork with respect to underground conditions that have eluded identification by conventional core-drilling methods. To the medical profession it may well signal new progress in photo optics which could result in cylindrical color photographs supplementing the X-ray and existing photographic methods used in exploratory surgery.

Jan 8, 1954

By John J. Schanz

THE highly publicized shortage of students enrolled in engineering curricula has brought about a rapid increase in the enrollment in engineering schools in many parts of the country. Though most of the various curricula in the mineral industries field have participated in this increase, the experience at Pennsylvania State University has been that the nonmineral types of engineering have been increasing at a much more rapid rate than those in the College of Mineral Industries. [ ] It has been a matter of some concern to the staff of the College of Mineral Industries that enrollment in the curricula of the school has not been increasing at a rate commensurate with that experienced in the College of Engineering. If the lack of trained young graduates for our vital mineral industries is to be overcome, this situation must be remedied.

Jan 8, 1954

By D. T. Van Zandt

IN the late 1920's rotary drills began to replace the churn drills in the petroleum industry, but until the middle 1940's the churn drill was the only widely accepted means of drilling large-diameter blastholes for quarry operations. The Calcite plant of the Michigan Limestone Div., U. S. Steel Corp., was one of the first to experiment with rotary drills for quarry blasthole drilling, and the first to employ compressed air on a fully rotary rig to cool the bit and raise the cuttings to the collar of the blasthole.

Jan 8, 1954

By Frank Doxey

AT Dominion Steel & Coal Corp. it has long been recognized that continued mechanization of mine operations is necessary in the Pictou, Cumberland, and Sidney coal fields of Nova Scotia. The varied physical conditions in these fields call for special consideration of individual cases before planning is finalized. Because standard equipment cannot be procured which would operate successfully, many experiments have been necessary over the years to keep pace with the progress made in other countries. There are two mines, producing 2000 tpd, located in the Pictou coal field. The field is badly distorted and crossed by many faults. Seams are highly inclined and irregular and vary in thickness from 5 to 40 ft. Entries are difficult to maintain because of squeezing of the coal ribs and movement of the roof and pavement.

Jan 7, 1954

By H. I. Ashby

INITIAL development of the south orebody at San Manuel is being carried out from the No. 1 and No. 2 shafts. The haulage and grizzly levels are being driven to develop the upper one third of the massive hydrothermally altered and fractured monzonite orebody. This first haulage level has been placed at the 1475-ft level with a grizzly level 60 ft above. The grizzly level will be connected to all service shafts so that men and supplies can come down to the grizzly level and go to working places without congesting the haulage level. These connections are also a vital part of the ventilation plan. The haulage level is being advanced along the north and south fringes of the orebody and connections are being driven to the three shafts now under construction. The No. 1 and No. 2 shafts will serve the development work with supplies, skip hoisting, and ventilation at each shaft and the two shafts are connected on both the grizzly and haulage level.

Jan 7, 1954

By C. L. Pillar

TWO shafts have been completed since the spring of 1948 when underground development started, and three are now under construction. The new program provides two main ore shafts, Nos. 3A and 3B, spaced 195 ft apart and located on the south- western end of the orebody. It is planned that eventually 35,000 tons of copper ore per day will be hoisted by these identical four-compartment shafts. The third shaft of this new group is 600 ft from the present No. 1 shaft and will provide caged sup- plies for the underground mining operations. This No. 4 shaft has the largest cross-section of any shaft in Arizona.

Jan 7, 1954

By A. F. Meger

REPRESENTED here are the ideas and varied experiences of many people in the Hanna Coal Co. who have helped develop, over a number of years, an efficient and flexible method for spraying con- trolled amounts of oil on coal. Since the George- town preparation plant began operations early in 1951, oil treatment of coal has received special attention. It is believed that oil treating will satisfy present customers and also attract new markets. The first step in developing the new method of oil spraying was the construction of a dust cabinet for testing 50-lb samples of treated coal with the available oil sprays on the market. Tests results were tabulated for both indoor and outdoor storage.

Jan 7, 1954

By J. H. Wernick

IN a study of the rate of decomposition of ½ -in. cubes of limestone, dolomitic limestone, and dolomite in a sweeping nitrogen atmosphere, Joseph, Beatty, and Bitsianesl found that the zone of calcination advanced at substantially a constant rate at a given temperature. The purpose of this paper is to show that their data indicate at least two processes occurring when the above carbonates decompose. It is suggested that there are two processes occurring temperature range and the other the limiting process over another temperature range. The data of Joseph and co-workers have been extended by use of the Arrhenius equation, Eq. 1, a relation beween the velocity constant k of a reaction and the absolute temperature T.

Jan 7, 1954

By Lloyd Pollish, Robert N. Breckenridge

SUCCESS in any underground mining operation is determined by accessibility of the orebody, which in turn is dependent upon maintenance of passage- ways to the mining zones and temporary support of the voids caused by extraction of ore. This is accomplished by one or a combination of the following methods: timbering, back-filling, pillaring, or, more recently, rock bolting. Timbering has usually been the principal means of maintaining these underground openings necessary for mining operations. Timber, however, does not prevent ground movement beyond the scope of localized sloughing, which is indicated by the gradual failing of the timber itself. Besides this, timbering has always been a costly process, and with the decline of available supplies of timber close to the mining areas, mining men have constantly sought other methods of controlling ground.

Jan 7, 1954

By R. T. Hukki

THE accepted basis of comparisons between mills of different diameter is the percentage critical speed. [ ] In the following analysis capacity, T, is expressed in short tons per hour, tph, and power consumption, P, in kilowatts, kw. Accordingly power consumption per unit of capacity, Po, will be expressed in kilowatt hours per short ton, or kw-hr per ton. In all equations D refers to the inside diameter of the mill in feet and v to the peripheral speed of the mill in feet per minute inside the liners. Comparison between separate mills must be based on equivalent grinding conditions, i.e., same feed, same size distribution of feed, same size distribution of product, and same percentage of solids. In addition, comparisons between separate rod mills must be based on the same rods, same type of liners, and same percentage rod load. Comparisons between separate ball mills presuppose the same balls, similar liners, and same relative ball load. The practical np-range through which the equations apply varies, being narrower for fine grinding in ball mills and wider for coarse crushing in rod mills.

Jan 7, 1954

By H. S. Strouth

JAMAICA-bauxite and gypsum-but what else? J Does the Caribbean island have anything more to offer in the form of mineral wealth? One answer may be iron ore deposits which show enough promise to warrant exploitation in the near future by a company associated with Standard Ore & Alloys Corp. In addition, Jamaica is reported to have gold, silver, platinum, copper, lead, zinc, manganese, cobalt, and a great many nonmetallic minerals. Of these, only platinum has not been produced commercially in the past. Right now, Jamaican bauxite is getting most of the publicity, but not too long ago other mining operations were in progress. Lack of proper interest, insufficient roads, and scarcity of venture capital forced those mining properties to suspend production.

Jan 7, 1954

PLANS for development of the San Manuel ore- body have been worked out and are progressing parallel with construction of the surface plant. This property lies in the Old Hat mining district, Pinal County, Ariz., about a mile south of Tiger where the St. Anthony mine once produced gold, molybdenum, vanadidn, lead, and zinc. Two development shafts have been completed and serve as ingress for preparation of the 1475 haulage level and 1415 grizzly level. Three other shafts are being put down. The Nos. 3A and 3B shafts will provide the ore hoisting facilities. The No. 4 shaft, now being sunk, will be at the main mine service and supply yard, with primary function to provide the mine with supplies.

Jan 7, 1954

By G. H. Wilson

INTRODUCED in 1946 to serve a need in power- plant operation, closed-circuit TV has been used by well over 200 organizations in approximately 25 different industries. Known as industrial television, or simply ITV, it can be described as a private system wherein the television signal is restricted in distribution, usually by confinement within co-axial cable that directly connects the TV camera to one or several monitors, Figs. 1, 2. The picture is continuous and transmission is instantaneous, permit- ting an observer to see an operation that may be too distant, too inaccessible, or too dangerous to be viewed directly. Destructive testing or the machining of high explosives can now be conducted hundreds of feet away by personnel who still have close control through the eyes of the TV camera. It is also possible for one man to control operations formerly requiring the co-ordinated efforts of several workers. For example, at a large midwestern cement plant conveyance of limestone from primary crusher to raw mill and loading into five storage bins once necessitated the work of two men, one having little to do but prevent spilling of material by manually moving the tripper on the belt conveyor as occasion required. TV cameras mounted on the tripper now provide bin level indication to the conveyor operator at the crusher position so he is able to control the entire loading operation remotely, Fig. 3. By means of a switch, the picture from either camera is alternately available on a single viewer, or monitor, Fig. 4. Each camera is mounted on the tripper by means of a simple adjustable support and looks down into the bin, which is identified by the number of cross members on the vertical rod. Each associated power unit is located on a platform above the camera, Fig. 5. This centralized control by means of TV often has produced superior results, and in many instancés saving in operating costs has been sufficient to write off equipment costs within six months to a year.

Jan 7, 1954

By O. G. Lellep

IN every country economic circumstances prescribe the method used to produce a commodity at lowest cost. In Pennsylvania a man's wages for working 4 hr buys a ton of coal wholesale; in Germany a laborer must work 40 hr, or ten times as long. In western Europe, therefore, conservation of fuel is of primary importance, and recent practices of burning lime and cement differ from those employed in the United States. This paper presents data collected during a trip through western Europe in 1953. Considered uneconomical, shaft kilns for burning cement disappeared in the United States two generations ago. But because required capital investment is low and operation greatly improved, shaft kilns are still used to some extent in Europe, where fuel costs are high, and are even included in designs for plants under construction. During the last 50 years shaft kilns have been maintained at the same physical size, while their output has been increased at least four times.

Jan 7, 1954