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Oceanographers are tooling up. Back of the build-up is Navy defense work and private business. Business is dipping toes in the ocean gingerly and not sure whether the motivation is based on logic or intuition. The problem is that new business opportunities in the oceans could explode rather than evolve. The question is when. At stake for earthlings are food supplies, mineral resources, oil and gas, weather forecasting, navigational systems, shore erosion control and sewage disposal, as primary targets. "Twenty years ago, offshore oil seemed a remote possibility for economic exploitation but today it is a reality. It became a reality largely because of the development of practical ocean seismic equipment and drilling platforms. Today the oil industry is looking at submerged-type drilling rigs. Mineral exploration in the sea is more expensive than on land now primarily because familiar land tools are being modified for sub- marine work." These were the ideas expressed by C. G. Welling of Lockheed Missiles & Space Co., at one of the many meetings that have taken place so far this year on development of marine resources. Welling's views indicate the rationale of companies that have already invested in the sea. Many companies, including those in mining, have observers who caution, "go slow." The continental shelfs and even the deep ocean floor represent to the mineral industries the age-old, enigmatic confrontation-is this the time to move? To no other industry, except Defense, are the results of correct timing so vital.

Jan 8, 1967

By George A. Lamb

Forecasters, in estimating long-term energy requirements and supplies, have predicted a bright outlook for coal. Some predictions have annual coal output reaching 800 million tons by 1980, almost twice the average of the last five years. These projections assume that ultimate consumer energy products will be supplied adequately not only in volume but also by kind and type. The consumer energy schedule shifts continually as it reflects the changing demands for numerous uses. Its appearance, expressed generally in proportions of solids, liquids, gases and electricity, is quite different today from what it was in 1940. It may change even more by 1980. Thus, the shares that coal and the other energy sources will have In total supply will depend upon how well each source can be processed into products that will be accepted by consumers.

Jan 7, 1963

By J. L. Bruce

For a number of years, from an economic standpoint, the ventilation of the Colorado mine of the Davis-Daly Copper Co. has been a difficult problem. The development through the main hoisting shaft was pursued for a number of years and to a depth of about 2500 ft.( 762 m.)before large bodies of good commercial ore were opened up. This lack of early success in exploration restricted expenditures for ventilation, with the result that the present orebodies were opened up at a depth of 2500 ft., and in country rock f relatively high temperature, without adequate means f supplying the development faces and the stopes with cool or fresh air of low humidity and suitable velocity. During the progress of development, two or three connections were made at higher levels with the workings of adjoining operations, but these were of a makeshift and unsatisfactory character and afforded no means for carrying downcast air from the surface, in anything approaching a direct course, to the working faces. During the latter part of 1917, arrangements were made with. the Anaconda Copper Mining Co., whereby, during the year 1918 and the early part f the year 1919, a crosscut was driven eastwards on the 2500-ft. level of the Colorado shaft and connection was made by means f an up-raise of approximately 200 ft. to a crosscut driven westwards from the 2800-ft. level of the Belmont mine, this crosscut at the top of the raise being driven at Davis-Daly expense by the Anaconda Copper Mining Co. This connection, in conjunction with a No. 11 Sirocco fan installed near the Colorado shaft, provided the Colorado mine with a maximum of approximately 30,000 cu. ft. per min. of relatively fresh air, most of which came in a fairly direct route from the downcast Belmont shaft through the No. 11 fan to the 2500-ft. level stopes. After passing through these stopes and the stopes of overlying levels, it passed through the main crosscuts on higher levels back to the Colorado shaft, which provided the upcast for this current of air. The improvement

Jan 9, 1921

H. Van F. Furman, Denver, Colo. (communication to the Secretary): There are some statements in Dr. Carpenter's interesting paper which appear to require explanation, if not modification.

Jan 1, 1901

Beverley S. Randolph, Frostburg, Md. (communication to the Secretary): It has always appeared to me that each coalseam has its peculiar character or habit, due to the conditions of its formation, by virtue of which it is either persistent or variable in its section over extended areas. One seam will hold its thickness, chemical character, number and position of partings, beds of slate, etc., over a large area, while another will be found to vary in some of these characteristics every few feet. As the position of the outcrop is an accident of the topography, depending on folding and erosion which have taken place since the bed was formed, no one opening in the outcrop, or, in fact, anywhere else, can supply reliable evidence as to the general character of the seam. To determine the character of an untried seam, a number of sections are necessary from widely separated points, in order to show such variations as may exist. Should material variations be developed, more numerous sections are necessary, in

Jan 1, 1901

W. S. GRESLEY, Erie, Pa. (communication to the Secretary): A six-entry method of opening coal-mines is, or was a short time ago, practiced in the Connellsville coal-region; but Dr. Chance's method has a novel aspect; for while in the Connellsville region the main pillars are formed outside of two pairs

Jan 1, 1901

Prof. Henry M Howe, New York: It is extremely probable that this efflorescence of silica is due to the liquation either of silicon or of a silicide, and the subsequent oxidation of the silicon to silica. As Mr. Fackenthal says, it is very hard to see why silicon should liquate from an iron containing so little silicon, and it seems more probable that some silicide of some volatile element has liquated, and has dissociated on reaching the air, and that the volatile element has volatilized, leaving the silicon to oxidize to silica. The volatile elements present which might thus liquate in combination with the silicon are sulphur, zinc, and lead. It is hard to see why sulphide of silicon should have liquated from an iron containing so little of either sulphur or silicon. At first, one naturally thinks that either the zinc or the lead present in this furnace might have liquated as silicide. It is true that they are both volatile at the temperature within the furnace, but then the vapor-tension* of each of them within

Jan 1, 1901

A. R. Ledoux,New York City: The so-called combination method " is generally used in assaying bar copper for silver. It has been modified from time to time. Briefly outlined

Jan 1, 1901

Fred. T. Greene, Rossland, B. C. (communication to the Secretary): At the beginning of his gaper, Mr. Herzig refers to an article of mine in the Engineering and Mining Journal of January 27, 1900. I would like to add that the method de-

Jan 1, 1901

George L. Heath, South Lake Linden, Mich. (communication to the Secretary): In presenting some notes on the "Heine's Blue Test" Mr. Smith expresses a preference for fresh standards and a cheaper bottle; but this is rather a reversion to the old method, since I devised in 1897 the newer method of preparation and preservation of' permanent standards, which were not used with any success in the original method. Many busy western assayers no doubt value a method for preparing a permanent set of standards in air-tight glass-stoppered bottles, whose use brings the method as near perfection as one could desire as regards rapidity of color-reading and avoidance of unnecessary work. Mr. Smith notes that his color-readings were compared with an electrolytic assay of another ore-sample, and that my electrolytic assays were made on the " blue test" solution from colorimetric assay. He omits, however, reference to the fact, showing the advantage of my procedure, that the next column in table of

Jan 1, 1901

In discussing Mr. Keller's paper, I quoted the results obtained by Mr. Allan Gibb, correctly crediting them to Mr. Gibb, with due reference to the report in which they were published. But in the table immediately following, and in my further remarks, following the table, I find that, by some clerical or other error which I cannot, after the lapse of time, explain, I spoke of Mr. Gibb as Mr. "Dean"—a metallurgist who had written on a related subject, but not on the point I was discussing. In short, my reference throughout was to the work of Mr. Gibb; and by reading a Gibb " for a Dean " in all places on pp. 832 and 835 where the latter name occurs, my remarks will be brought into accordance with my intention, and with the facts.

Jan 1, 1901

Jan 1, 1901

W. M. Courtis, Detroit, Mich. (communication to the Secretary) : Having made a rapid examination of the deposits described in this paper, I am not inclined to generalize confidently concerning its geological relations. But, since an analysis furnished by me has been included in the paper, it may be of further use to give the results of other samples and analyses. I give, therefore, a table of analyses by different parties, showing the average from surface-specimens:

Jan 1, 1901

By Alan K. Burton

An industry-wide demand for bigger and more efficient trucks, with their supposed economies of scale, is well established. Some trucks have been, and often are brought "off the shelf," with the manufacturer offering only certain minor options, much as in the private automobile industry. The market is well established; there is keen competition; in recent years there have been few significant changes, and few are expected. With large trucks (100-ton-capacity and over), however, the situation is different. Here, with an individual truck costing several hundred thousand dollars, there is an ever in- creasing trend to engineer a truck for a specific application. The body will be designed and sized for the material that the truck will carry; the engine and transmission will be geared to the haul profile, and tires will be designed to suit road conditions and work requirements. Early Truck Development Haulage trucks designed expressly for open-pit mine service were introduced during the 1930's. The first models to arrive on the scene hauled about 15 tons, and easily outperformed the modified highway trucks that had been used for mine haulage up to that time.

Jan 8, 1975

By Alan K. Burton

Along with tires and transmission systems, engines have been a limiting factor in the growth of large off- highway trucks. The problem, primarily, has been the development of reliable, high-performance engines that are not prohibitively heavy or expensive. For many years, horsepower to overall truck weight ratios have been in the vicinity of 300 lb per hp for rear dump units up to 50 tons capacity. This ratio is obviously very poor when compared to the much lighter and smaller highway trucks, which frequently have a performance ratio of 100 lb per hp. Unfortunately, the larger mining trucks have not been able to match even the 50-ton trucks, and in some cases, ratios have dropped as low as 450 lb per hp. This results in a performance of only 67% of that achieved by the older smaller trucks. Thus, the message is clear: what is needed is more horsepower and less weight.

Jan 10, 1975

By Alan K. Burton

The number of trucks required to perform a certain task is a function of the productive capability of one independent truck and the total tonnage required. Hourly productive capability of one truck is the product of trips, or cycles, per operating hour and effective payload. One cycle is made up of load, dump, and travel time, the sum of which comprises theoretical cycle time. This time is then derated by a productivity factor, giving an average effective cycle time which is used to calculate the number of cycles per hour. Rated payload is the truck's designed tonnage, while effective payload is the average amount that is actually carried. Manufacturers, particularly of the larger trucks, produce various body sizes designed to carry materials of different densities. However, it is not always possible to carry the rated payload because the material might be lighter than expected, a body of the required size cannot be produced, or because of spillage on particularly steep grades.

Jan 12, 1975

By Alan K. Burton

The individuality of off-highway trucks is largely determined by a number of truck components that include beds, frames, and suspensions. With the exception of tires, these features are generally standard equipment and the mine operator gets "what comes with the truck." With the advent of larger trucks, more complicated haul profiles, and sophisticated production control systems, a new truck support-component industry is rapidly appearing. The impact of the new options for off-highway trucks can be significant in terms of future fleet performance. Innovations include "Mesabi" radiator cores that reportedly offer greater engine temperature control; load indicators that insure proper truck loading at the shovel; and digital communication systems that signal truck status in the haulage cycle. An understanding of tires, brakes, and newly introduced support components is necessary before an optimum choice of truck can be made

Jan 11, 1975

By T. W. Peterson, J. W. White, E. E. Krist

In developing a minicomputer application for an industrial grinding circuit, the control program is usually coded and the compilation is debugged on a remote access computing system. Final debugging must wait for installation of the minicomputer. This work reports on an alternative. Here both compilation and execution bugs are eliminated before the hardware is installed by testing the control program against a dynamic simulation. Attention is directed toward development of a particular real-time control program for an industrial wet grinding circuit in a copper concentrator. Specific data were supplied by the Anamax Mining Co. for a grinding division consisting of a rod mill followed by two ball mills in parallel. This information was used to set up a plausible model structure.

Jan 1, 1977

Jan 1, 1934