Search Documents

The following very cordial letter, addressed to the President of the American Institute of Mining Engineers by the President of the graduates of the School of Mines of Saint-Etienne, will he deeply appreciated by all American engineers and will perhaps be of use to engineers going "Over There." Members are requested to communicate the substance of this letter to friends or acquaintances in France: Dear Mr. President: Now that the American armies are crossing the ocean to come to our side in the defence of the liberty of the world, and the intellectual elite of your great country is very ably cooperating with us in this supreme struggle, we ardently desire to give them a whole-hearted reception upon their arrival on the shores of France. The representatives of your illustrious association will be more especially welcome among their French colleagues, and both at Saint-Etienne and at Pans, we desire that their sojourn he rendered comfortable and congenial in every way possible. We therefore put ourselves unreservedly at their disposal. At Paris especially those of our colleagues

Jan 7, 1918

At the office of the Chief of Engineers, Washington, there is a unique collection of engineering material used and developed in the present war. It. is a most interesting group of war devices, from the special trench shovel that excavates both gas and water, to the standard gage locomotives that were sent to France so complete that they were lifted from the ships by cranes, placed on the-rails on shore, filled with water, fired up, and moved out from underneath the cranes under their own steam. Everything is exhibited either by models, or by photograph where the original samples are too large to admit of demonstration in an ordinary office. The forestry section has an interesting exhibit of the wonderful work clone in France; where, owing to the shortage of coal and the necessity for burning wood, the Forestry Unit of the A. E. F. in one month stacked up 60 mi. of cord wood (80,000 cords); also cut 6.6 mi. of timber, stacked 12 ft. long, and 10 ft. high, containing 50,000,000 hoard feet of sawed timber.

Jan 3, 1919

Meeting of April 24, 1914.-President Thayer announced the appointment of the Committee on Safety and Sanitation. The Committee on Nominations for officers for 1915 was appointed, as follows: William J. Cox, Chairman; H. Poster Bain, Joseph Daniels, Charles E. Mills, R. V. Norris, E. Gybbon Spilsbury, and Herbert A. Wheeler. The request of twenty residents of Salt Lake City and vicinity for permission to establish the Utah-Nevada Local Section was granted and R. C. Gemmell was appointed Chairman of the Committee on Organization. The following resolution was adopted: Resolved: That under authority of Article V, Section 7, of the Constitution, a special Committee be and hereby is appointed, to consist of the President and six other members of the Institute, to be named by him, Who shall be authorized to appear before the proper authorities at Washington and urge that Mining Engineers be appointed upon the proposed Commission for revision of the Federal Mining Laws. Further Resolved: That the activities of this special Committee be restricted to the authority given in this resolution.

Jan 6, 1914

By F. C. Bond

B. H. Bergstrom (Allis-Chalmers Mfg. Co., Milwaukee)—In reading this article, it was difficult to follow through the example given as a starting point in the derivation of the theoretical equation which relates ball size to feed size. A discussion with F. C. Bond led to the following clarification: Bond postulates that "the breaking force exerted by a ball varies ... as the cube of its diameter . . ." and that the force in pounds per square inch required to break a particle varies ... as its diameter squared." He concludes: "It follows that when a l-in. ball breaks a 1-mm particle, a 2-in. ball will break a 4-mm particle, and a 3-in. ball a 9-mm particle." The above example can be true only for a different set of assumptions. Since the first assumption is apparently true, it is the second that must be revised. The second assumption should read that the breaking force required to break a particle varies as its diameter to the 3/2 power. This relationship was derived in the next paragraph of the article.

Jan 1, 1960

By Robert H. Richards

In the latter part of December a batch of amalgam was retorted and the tin in the retort uncovered while at a low red heat, and allowed to cool slowly to a temperature more suitable for ladling into moulds. It was then ladled and made what appeared to be nice, white, malleable block tin. On February 15th our attention is called to the fact that the tin is brittle, and on examination we find that the molecular condition of the pigs has changed to the extent of one-half its material. The change shows itself by an enlargement appearing on the surface something like crystallization, and comes in spots. The condition of the metal in these spots is very peculiar. It has changed from a malleable metal to a brittle one, with a structure somewhat resembling stibnite, and a color very considerably darker gray than tin. The analyses of the two parts of this tin pig showed the following results: Mercury. Tin. Specific Gravity. Crystalline part,.....2.62 97.24 6.175 Malleable part,.....2.38 97.50 7.387

Jan 1, 1883

SOUTHERN CALIFORNIA LOCAL SECTION Executive Committee THEODORE B. COMSTOCK, Chairman SEELEY W. MUDD, Vice-Chairman FREDERICK J. H. MERRILL, Secretary-Treasurer, 631 Higgins Bldg., Los Angeles, Cal. A. B. CARPENTER C. COLCOCK JONES A meeting of the Southern California Local Section, in honor of the presence of Secretary Bradley Stoughton, was held at luncheon in a private dining room of the Sierra Madre Club on Friday, May 21, 1915, 27 members and guests being present. In the absence, through illness, of the Chairman, Dr. Comstock, the vice-Chairman, Seeley W. Mudd, presided. After the luncheon, Secretary Stoughton made a short address on the activities of the Institute. George S. Rice, of the U. S. Bureau of Mines, who was present, then spoke on the activities of his Bureau. Local Secretary F. J. H. Merrill gave a description of the activities of the Southern California Section and its progress, and reported the latter as substantial and its condition as very good. After some informal remarks by other members present the meeting adjourned. F. J. H. MERRILL, Secretary.

Jan 7, 1915

Canadian owned Lake are carriers will be used again this year in an attempt to make up the deficit caused by the two months steel-strike. Buffalo mills need between 5 million and 6 million tons of ore before the Lakes navigation season ends. Mutual Security Program aid will help reactivate Austria's largest iron ore mine. The Erzberg development is one of the moat important in Europe. MSA announced approval of $500,000 in supplemental financing of equipment. Following the war, the Russians stripped the Erzberg and Radmar deposits of equipment. The he Carborundum Corp. is going to build a $2.44 million plant at Akron, NO.. TOP near Niagara Falls for production of rare metals used by the Atomic Energy Commission. A subsidiary, the Carborundum Metals Co., Inc.,, will produce zirconium, hafnium sponge metals. The pyrochlore rich Sukulu Hills in Eastern Uganda will be mined under a pool arrangement including Tinto Mines, Monsanto Chemicals and Frobisher Mines. The combine will be known as the Uganda Development Corp., Pyrochlore is used in the manufacture of heat-resisting. alloys for Jet engines.

Jan 1, 1952

HENRY M. Howe, Bedford Hills, N. Y (written discussion*).¬Mr. Foley's explanation of this interesting occurrence is perfectly reasonable. Possibly a word explaining the phenomenon more in detail may not be amiss. In the act of solidification each drop as it starts to solidify splits up into a half drop poorer in carbon and another half drop richer in carbon than the drop itself. The half drop poorer in carbon solidifies and attaches itself to-the already solid walls, whereas the half drop richer in carbon remains molten for the excellent reason that it is richer and hence is more fusible than the original drop, and hence in turn is wholly fusible at the existing temperature. Under usual conditions, as when the steel solidifies in a mold of any form, the successive molten half drops thus enriched in carbon remain present and by their enrichment progressively raise the carbon con-tent of the remaining molten mass, out of which successive half drops are continuously solidifying and attaching themselves to the already solid walls. Because the molten mass thus. becomes progressively richer

Jan 10, 1919

By John McDonald

THIS report is a continuation of an earlier one with a similar title,1 to which the reader is referred for such details of procedure as do not appear here. A brief summary will be given of the objects and methods of the research at this time. It was pointed out in the previous paper that properties of magnesium alloys, as re-ported by different workers, often differ. This was thought to be due to differences in the preparation of the specimens tested. The ideal way to compare alloys would be to prepare each of them in so many ways that reasonable assurance would exist that the best properties of each alloy had been developed. The alloys would then be com-pared on the basis of these properties. The treatment actually given the alloys of these studies is necessarily a compromise with completeness. Nevertheless, enough treatments have been given so that a con-siderable degree of assurance exists that the properties obtained are representative of the alloy as such, and not merely of the manner in which it was worked and heat-treated.

Jan 1, 1940

By W. R. Ingalls

SOME months ago, I had occasion to make an investigation that introduced the subject of blue powder that is produced as a byproduct in zinc dis-tillation. Although every zinc smelter is aware that more or less blue powder production is inevitable and there is a common practice as regards the treatment of it, the specific and quantitative data respecting the subject were more imperfect than would have been expected. I had reports from eight important works. Some of the data were especially determined for my investigation. Speaking generally, there is a good deal of uniformity in the figures, all of which show that the blue powder product, bears a large proportion to the ore originally charged into the retorts; that a large proportion of the retort capacity is devoted to the redistillation of blue powder; and that of the spelter product of a furnace about 30 per cent. is derived from blue powder, i.e., it is zinc that has been distilled twice. The figures from the works are given in the following table:

Jan 4, 1922

By Leonard Waldo

(New York Meeting, February, 1911.) THE recent and rapid development of the physics of engineering materials at temperatures as low as that of liquid air and as high is that of the electric are, has drawn renewed attention to the absence of tables, properly printed and spaced, for the convenient and accurate translation of temperature from centigrade to Fahrenheit scales and vice versa. It is to be noted that the Fahrenheit scale is the almost universal usage in foundries and shops in the United States, though the laboratories of the same works employ the centigrade notation. The growing use of the electric furnace in Germany and France calls for much American citation all in centigrade high temperatures, and while the arithmetical calculation is simple, it becomes burdensome when often repeated. I have been surprised at the numerous reprints of Table I. from centigrade to Fahrenheit degrees, first privately printed for personal use, which have been made by works, blue-prints, test-books, and technical journals, and I hope that Table II., from Fahrenheit to centigrade degrees, will be equally useful.

Jan 4, 1913

By Francis J. Dennis

Many factors govern the value of dredging-ground, and much capital can be wasted by the mistaken policy of contracting for the purchase of property arid the installation of machinery before a thorough examination has been made. To the uninitiated investor the presence of gold is generally the criterion, and very superficial evidence is necessary to satisfy him as to this point. he couuiclers the comprehensive report of a competent engineer as a wasteful extravagance, aild cannot understand why the engineer requires so much time and money to ascertain the information on which to base his conalusions, when the promoter can furnish him such pleaaing and satisfactory data with but little expenditure of time aud money. The uninitiated investor will often optimistically risk capital for purchase and equipment, and riot uiitil the veuture comes to grief does he learn that the condition8 are wholly unsuited for dredging. In many instances, a short preliminary examination by a competent engineer would have disclosed these facts. The mere presence of gold is by no means suficient; sonie of

Jan 1, 1912

By J. B. Dilworth

Outcrops of coal have been discovered in many localities in the Philippine archipelago, and practically all of the larger islands contain deposits of this mineral. Very little prospecting has been done to determine the value of the various cod-bearing areas, but so far as known, the largest and most promising fields are found: (1) in northern Cebu; (2) in the small island of Batan, a part of the province of Albay in southeastern Luzon; (3) in the somewhat larger island of Polillo, off the east coast of Luzon, and (4) in southern Mindoro, near the small coast town of Bulalacao. Northern Panny, south-central Cebu, and various localities in southern Luzon, Masbate, Negros, and Mindanao also afford evidences of the existence of coal-beds, the extent and value of which have not yet been proved. The general position of these islands and districts is shown on the map of a portion of the Philippine Islands, Fig. 1. Some of these coal-fields have been known for many years (coal was discovered in Cebu in 1827 and in Batan in 1842),'

Jan 1, 1909

By Peter N. Calder

This paper deals with the reinforcement of igneous rock slopes at three open pit iron ore trines in northern Canada. The pits involved utilize overall slope angles in excess of 60º with ultimate depths in the order of 250 m. Three case studies are described. The first concerns the reinforcement of a 300,000 Ton undercut rock wedge, approximately 70 m in height. This was accomplished using 20 cm diameter steel bales, installed in 25 cm diameter vertical holes, and a cement-sand grout. The second involves the reinforcement of a 40 m wide diabase dyke which had been continuously failing as the pit deepened. A unique form of rock reinforcement was used in that the entire mass of the undercut dyke was not pinned to the wall. Rather an interlocking effect between individual blocks within the dyke was relied upon. A third concerns the reinforcement of a berm which was undercut by the contact between the ore and waste. This reinforcement was also accomplished using a combination of steel bales, rods and cement grout.

Jan 1, 1982

By Charles M. Haas

WHEN minable ore has been located, the problem of mining is synonymous with the problem of movement --movement of men and equipment to mine the ore, and movement of the ore from the earth to the mills. In slusher drifts and shafts, on shovels and dragline excavators, on churn drills and bulldozers, wire rope is essential to the transportation of men, ore, overburden, and equipment. Although a casual glance creates the impression that all wire ropes are alike, there are crucial differences between ropes. Strand diameter, number of strands, weave, core, and resistance to corrosion all decide the type of job a wire rope can do, and where and how long it can do that job. These factors are, of course, the responsibility of the rope manufacturer. Beyond this, he can extend his function into the mine itself by advising users on the use, care, and maintenance of these sinews of the mining industry. This article, then, covers both the manufacturing and end-use aspects of wire ropes.

Jan 9, 1951

By William B. Plank

THERE are 19 pct fewer undergraduate and graduate mineral engineering students enrolled in the ECPD accredited schools of the United States this year than there were a year ago. The figures are: 8727 this year and 10,674 last year. The entire engineering group in both countries numbers 171,070, as compared with 184,547 last year and 252,250 in 1947-48, the peak year. This is a decrease of 7.3 pct since last year, less than half as much as the decrease in the mineral engineering group. These figures on engineering enrollment for the current year, 195.1-52, in colleges of the United States and Canada were prepared jointly by the U. S. Office of Education and the American Society for Engineering Education. The seriousness of the situation is shown. by the reported demand for 60,000 to 90,000 engineers this year for civilian and defense industries and only 35,800 will graduate next June. Many of the 1952 graduates are subject to Selective Service, having been granted deferments while in college, and ac- [ ]

Jan 1, 1952

By Frank S. Hurley

To comply with the California Mine Safety Orders pertaining to transportation of mine workers over mine railroads, the management of the New Idria mine in San Benito County, Calif., designed special man-cars. The new regulations, dated October 1958, make it mandatory for mine man-cars to be designed for carrying five or more men to and from the mine workings. At the New Idria mine, largest single producer of mercury in the U.S., each shift normally employs about 70 men. However, with the possibility of a future increase in the work force, seven man-cars were constructed with a total carrying capacity of 84 men. The general design of the mine man-cars was dictated by safety regulations plus the physical characteristics of the mine-low headroom, limited side clearance in haulageways, and track irregularities due to ground swells. The cars measure 10 ft long, 44 in. wide, and 50 in. high and were built at an average cost of $450 per car. All assembly work was done at the mine site.

Jan 7, 1960

By L. S. Castleman, L. L. Seigle

IN a recently reported investigation, J. B. Clark and F. N. Rhines1 used a diffusion couple technique to determine the number of intermetallic phases which should be present in the Al-Mg equilibrium phase diagram. Their method was an application of the following generally accepted principle. If a diffusion couple made up of two metals is annealed at a given temperature for a long time, all the phases of the binary system which exist under equilibrium conditions at the diffusion temperature will form intermetallic layers. It is important that the diffusion temperature be high enough and the diffusion time be long enough to permit the nuclea-tion of all thermodynamically stable phases at the interface of the couples and their growth to observable thicknesses. These simple time-temperature criteria are at times difficult to satisfy, and it is the purpose of this note to point out a situation in which this is the case. The authors are currently studying diffusion bonding in the Al-Ni system." It is well established

Jan 1, 1958

Open pit operators have found the dropball crane a great aid in cutting costs and hazards of secondary breakage. But a common problem in using the unit has been with the shock absorbing connection from the cable to the dropball itself. Blair Limestone Div. of Jones & Laughlin Steel Corp. has come up with a new connector to solve this problem and to save the time usually lost in frequent replacement of the cable slings, chains, or old tires hitherto used at this point. J&L personnel solved the problem by combining three ideas from other dropball crane owners. Their unit consists of two long U-bolts running through a heavy spring originally made for use on a vibrating screen. Heavy duty swivels attached to the bent ends of the U-bolts provide attachment points for the crane cable and the special chain to the dropball. Connection at the dropball is by an eyelet welded directly into the mass of steel, and a special alloy chain is connected to this with a clevis.

Nov 1, 1955

By Edward C. Roper

Pegasus' Gold Ltd. operates two gold/silver heap leaching operations in the Little Rockies area of Montana. The Little Rockies has produced gold from underground operations on an intermittent basis from the 1880's to the early 1950's and from the open-pits on a continuous basis since 1979. Run-of-the-mine ore is drilled, blasted, sorted, loaded and hauled. The waste is dumped and compacted into 30 meter (100 foot) fills to be used for future leach pads. The leach pads have a central drain system and the impermeable membrane is constructed of bentonite and 30 mil PVC. The plants which have beenexpanded to 4900 Ipm (1300 gpm) capacity use the Merrill-Crowe process for gold and silver recovery. 4600 liters (1200 gpm) of the 9500 Ipm (2500 gpm) spray capacity is recycled through the old leach pads for upgrading before being processed. The gold/silver precipitate is smelted and the resultant dore' is shipped to a buyerhefiner. 1983 projected production is 2,177 kg (70,000 02s) of gold at a cost of less than $10/gm.

Jan 1, 1984