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By Theodore J. Hoover

WHAT are the chief branches of the mining engineering profession today? In an effort to analyze the structure of the profession, for practical purposes, a quantitative study has been made of the membership of the A.I.M.E., and is herein reported for the first time. In spite of the effect that a long history and a relatively small group of professional workers have had in limiting specialization in mining engineering, there has nevertheless grown up a wide variety of specialties in this field. More than a hundred different kinds of engineers were discovered among the titles given by Institute members in the Directory, ranging from "advisory engineer" and "American engineer" down to "wire-rope engineer" and "works engineer." How should all these titles be defined and interpreted? How many of them should be relegated as meaningless or confusing? What are the relationships among the remaining useful designations? Should some of them be grouped as "metallurgical" or "chemical," or under some other head?

Jan 1, 1935

By Arno C. Fieldner

METALLURGICAL coke and the by-products of the carbonization of coal continue in strong demand. Nearly 500 new by-product ovens were constructed in 1943. Output of by-product coke in the first ten months of the year was about 2 1/2 percent higher than in the corresponding period of 1942, but beehive production remained on approximately the same level as last year and constituted about 11 per cent of the total coke output.

Jan 1, 1944

By Arthur Zentner

THE PAST YEAR saw important developments in all the main branches of zinc metallurgy, which can only be douched on briefly here. Vertical Retort Smelting-The New Jersey Zinc Co. reports their operations to be about as last year when the number of vertical retorts at the Palmerton plant was increased from 16 to 28. The first unit of eight vertical retorts at Oker, Germany, to treat the Rammelsburg complex ore was completed early in the year. A second unit has been under construction and is probably ready to start operations about this time. Each unit is rated for 10,000 metric tons of zinc per year. A plant of 40,000 metric tons annual capacity is the goal. A reflux plant was also built to make high-grade zinc. The plant program is being -carried forward with government finan¬cial assistance, as was the case with the electrolytic zinc plant at Magdeburg. Government subsidies cover mining and 'smelting, and allow for depreciation and reasonable return on invested capital, according to U. S. Bureau of Mines reports.

Jan 1, 1938

By L. R. MacLead

Delivery of tailing to any part of the area by gravity from the ridge was found practicable. Experiments with asbestos-cement pipe proved it possible to use level pipe across the dams if it is fed through an inclined section in which pressure could be developed. Use of pipe to transfer the tailing to the dams was not favored because of the possibility that choking might occur. Metal flume was not believed to have sufficient wear resistance on this material and wooden flume would not withstand damage by the weather so well- Flume -action made- of 26-in diameter asbestos-cement pipe, split before curing and molded to a specified cross section, were finally approved. The flume is connected to the 24-in. diameter tail in distribution pipe by heavy concrete lateral launders. Cascades of horizontal and vertical pipe sections are used at the top of the pressure leg where scouring by high-velocity flow of tailing might occur.

Jan 1, 1942

ENGINEERING department problems of unravel- ling filing systems of reference data, detail drawings, magazine tear sheets, technical records, manufacturers' catalogs-and coordinating them with the information classification systems employed by the company library and other information services -are being solved in many cases by adopting a basic classification system such as that used by Sweet's Catalog Service and applying its classification and indexing methods to file or bookshelf. By this procedure the engineering department does away with the confusion, duplication, and conflict that exist between personal, department, and company library files. It establishes a pattern for regulating and distributing the potential information that piles up daily in the engineering department basket marked "Incoming."

Jan 5, 1954

By W. D. Faulkner, J. E. Urbanic, R. J. Jula

The process of treating granular activated carbon for return to service in the recovery of gold in carbon-in-pulp and carbon-in-leach circuits has been investigated. Carbons from two US mines, one Canadian mine, and a South African pilot plant operation were characterized before and after regeneration. Thermal regeneration of the carbon was investigated using factorial analysis to determine the effect of interaction of furnace temperature, retention time, and use of supplemental steam. The operation of acid washing the service carbon was investigated, including a comparison of the use of nitric and hydrochloric acids. The effect of quenching regenerated carbon was also briefly studied. Prom the data obtained, guidelines are given for effective regeneration operation.

Jan 1, 1986

By AIME AIME

FEW indeed are the sections of the country where trained or partly trained workers have not already been hired by a war industry plant or will be within the near future. Yet right in the midst of the heavily industrialized East lies the anthracite area, home of a million people, whose productive power has persistently been by-passed either by private industry or by the Government Plant Site Board. The chief reason given for not locating war plants in the area is that it is not within the strategic zone, but in numerous instances elsewhere this rule has been waived. Furthermore, the anthracite region is well protected on all sides by mountains and is at all points more than 100 miles inland. Continued depression in the anthracite industry and a crippling blow dealt by the war emergency to the production of silk and rayon goods, the chief manufacturing activity of the area, have resulted in a heavy migration, particularly of trained young workers, into near-by industrial areas. At least 50,000 people are currently unemployed, with the likelihood of an increase in coming months, and as many families are on relief.

Jan 1, 1942

By M. A. Roche

AST fall over half a million tons of ore and rock were broken in one blast at the open pit of the Hudson Bay Mining & Smelting Company's operation, at Flin Flon, Manitoba. The following particulars of the blast, and details of the preparatory work, indicate how an operation of this scope is carried out. The data given, in essentially the present form, were first published by The Canadian Mining Journal. The area blasted was 150 ft. wide and about 700 ft. long. A total of 123 tons of 50 per cent forcite gelatin, in 5 by 16-in. cartridges, was used for the charge. Drilling for the blast was started on May 29, and was completed late in August, requiring 1297 machine shifts for drilling only. Total footage drilled for the shot was over 5 miles of 6-in. hole. The main blast consisted of 232 holes spaced on 17.5-ft.

Jan 1, 1934

By D. R. THOMAS

GENERALLY speaking, the production of other metals in Mexico fluctuates with that of silver. The first commercial discovery of mineral was in Taxco, Guerrero, in 1552. Five years later, the patio process was introduced at Pachuca, by Bartolome de Medina. In 1884, the main line of the Mexican Central R. R. was completed and a few years later, the National railway. In 1907, the patio process, after 350 years of successful operation, was replaced by cyanidation. Soon after the completion of the railroads, smelters were built at various points and provided means of treating ores that could not be treated by any of the processes existing at that time, such as patio, lixiviation, or pan amalgamation. As a result, a number of mines were developed along the railroads and even far \ out in the mountains. In order to facilitate the shipment of this ore to the smelters, purchasing agencies were established, which for a time were very profitable; most of these agencies are now permanently closed.

Jan 1, 1921

John S. Kennedy, Chamhersburg, Pa. (communication to the Secretary): The washing-plant described by Mr. Johnson is a good illustration of the advantages derived from a well-designed and care-

Jan 1, 1895

Jan 1, 1955

Jan 1, 1969

Jan 1, 1969

By J. A. Hutcheson

NO one questions that it is technically possible to achieve the controlled release of atomic energy in a form that can be converted into heat or electricity. However, before this is actually an accomplished fact a great amount of work must .be done. This work falls into two general classifications: research and engineering development. At present a research program is under way in this country, co-ordinated and directed by the Atomic Energy Commission, which, as time goes on, will uncover fundamental knowledge of this new science that is essential before industrial applications of atomic energy are practical. Undoubtedly therefore, as the store of available knowledge increases, a time will come when answers to the many questions relating to practicality of atomic energy in industry can be determined with reasonable certainty. That the application of atomic energy in industry will eventually be proved practical is assumed. What then are the engineering problems that must be solved before the first practical electric power generating station can be built?

Jan 1, 1948

By W. B. Heroy

ONLY through the mineral fuels can large amounts of energy be transported to great dlstances and stored for long periods for future use. Coal has the advantages over oil of greater safety of handling and smaller losses in storage. But oil is, in the present stage of technical advancement, the more economical source of liquid fuel for internal-combustion motors. No method for direct use of coal in such motors has been developed that can compete with petroleum products. The automoblle engine and the airplane motor are designed to make the most effective use of gasoline.

Jan 1, 1944

By Sherwin F. Kelly

PLAIN mining engineers usually avoid any gathering of geo¬physicists because of the incomprehensibility of their discussion to the uninitiated. This being so, gradients, gravity and gammas will be deferred to the end of this review, the first part of which will be devoted to what has been done in applying geophysics to the solution of real field problems. From the West, J. J. Jakosky reports that International Geophysics has had its activities fairly well 'divided between mining (both placer and lode), oil structural work, and clans-site and reservoir investigations. In oil exploration, electrical methods are used for depths down to 2500 ft., beyond which they utilize seismic methods. They find in their placer work that the many 'magnetic anomalies encountered in the bedrock of the Southwest render the electrical techniques more satisfactory, and with them they are obtaining thickness and tonnage of gravels, depth to and contour of the underlying bedrock as well as important structural features therein, and water-table elevations.

Jan 1, 1934

By JESSE L. MAURY

ONE OF the most hopeful features of the current depression is the discussion which it has en- gendered of ways and means to counteract similar recurrences in the future. 1t is widely recognized that fruitful attack will be directed toward the steady employment of labor, through which the purchasing power of this preponderant class in society will be maintained. S. A, Lewisohn's article' has presented the major factors to be considered; the physical suffering and mental torture endured by those who are deprived of income through no fault of their own, the direct economic losses' sustained in the degradation of 'great, numbers of our population and the disintegration of efficient working forces, and the prime responsibility of owners and managers.

Jan 1, 1931

By AIME AIME

A JOINT meeting of the Canadian Institute of Mining and Metallurgy and the American Institute of Mining and Metallurgical Engineers was held at Spokane, Wash., and Cranbrook and Kimberley, B. C., on Oct. 13 to 16, 1926, with a total attendance at one or another or all of the meetings of about 300 members, ladies and guests. At the opening meeting, on Oct. 13, in the Davenport Hotel, Spokane, about 175 were present. The morning was occupied with addresses of welcome by M. H. Sullivan for the Columbia Section, who called on Mayor Charles A. Fleming, President John F. Davies for the Chamber of Commerce, and E. R. Hannibal, president of the Associated Engineers, each of whom heartily welcomed the visitors. Philip N. Moore, former president, and special representative of President Samuel A. Taylor, replied for the A.I.M.E., and Lewis Stockett, president, and Charles A. Banks, chairman, British Columbia Division, Canadian Institute of Mining and Metallurgy, and Henry M. Parks for the visiting A.I.M.E. sections, made appropriate responses on behalf of those they represented. The members and ladies had luncheon with the Associated Engineers. Philip N. Moore addressed the assembly on "The Opportunity of the Engineer"; an excerpt from his address appears on another page. At the afternoon meeting, with Lewis Stockett in the chair, Frank M. Smith was asked to make a brief statement of the proceedings of the Silver Producers Association in Denver. Supplementing his talk by placing a well-prepared statement on "Silver and the Plan of the Royal Commission on Indian Currency and Finance" in the hands of those present, he narrated what had been undertaken by the Silver Producers Association and what they hoped to accomplish.

Jan 1, 1926

By AIME AIME

FREDERICK WORTHEN BRADLEY, the newly elected president of the Institute, may be said to be the prototype of the men who have built up the great mining industry of the West. He was born in Nevada County, Cal., on Feb. 21, 1863, and studied mining at the University of California from 1882 to 1884, as a member of the Class of 1885. He was in contact with the mining industry from his earliest years and in his reminiscences which we published last month, he told of meeting Thomas Mein and H. C. Perkins in 1877. Beginning as assayer and roustabout at the Eagle Bird mine, in Nevada county, Mr. Bradley was a deputy mineral surveyor in 1886 and 1887 and superintendent of the Spanish mine from 1885 to 1890. There he made a record of mining gold ore at 65 cents per ton that was not only astounding in that day when modern large scale mining had not yet been developed but is still a mark to shoot at. As a result he was called in 1890 to be assistant manager of the Bunker Hill and Sullivan and was made manager in 1893. In 1897, he was elected to the presidency of the company, a position he still holds. H. C. Perkins and D. O. Mills, the largest stockholders in the Bunker Hill and Sullivan Co. took over the Tacoma smelter in 1898, feeding it with concentrate from the Coeur d'Alene and Douglas Island mines but also doing a gen-era1 smelting business. Mr. Bradley was put in as president of the Smelting company, and held that position until the plant was sold to the American Smelting Securities Co. in 1905.

Jan 1, 1929

By A. M. Gaudin

THE so-called Kick law' is generally accepted to . mean that for each reduction to one-half in particle diameter, in a unit weight, the same amount of work is required. In crushing-efficiency calculations on crushing tests it is customary, when basing the calculation on Kick's law, to assign ordinal numbers to each standard sieve size. These ordinal numbers increase by a constant difference with each successive sieve aperture, because standard sieve apertures are in constant ratio. Minus 200-mesh is generally assumed as equivalent to 37 microns in size. By definition, the ordinal number multiplied by the per cent material of any size is equal to the energy units in the material of that size in a unit weight of sample. The sum of all energy units is the energy units content of a unit weight of sample, whether it be crusher feed or product. The difference between the energy units in the product and that in the feed is the tangible result of the work input per unit weight of feed. From this the amount of work necessary for one energy unit may be calculated. This has been done for a quartz crushing-test made at the Intermountain Experiment Station of the U. S. Bureau of Mines at Salt Lake City, in which the net work going to crushing was carefully measured. The results of this crushing test are given in Table 1.'

Jan 1, 1929