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By George J. Young

(Cleveland Meeting, October, 1912.) I. GENERAL. THE recurrence of mine-fires in Nevada during the past decade is not only a matter of interest, but also one of considerable concern to engineers and mine-managers. The more important fires may he enumerated as follows: Forman Shaft fire., Gold Hill, April 21, 1903 ; shaft-house, machinery, and shaft, destroyed; loss estimated at $50,000.; Cause Unknown. Union Shaft fire, Virginia City, July 14, 1904; shaft-house, machinery, and shaft in part destroyed; loss estimated it $100,000; cause of fire stated as the careless throwing of a match in the rope-house. Sutro Tunnel fire, Virginia City, Jan. 27, 1909 ; 700 ft. of tunnel-timbering destroyed, and direct damage of $10,000; cause ' probably electric wires." Belcher Shaft fire, Gold Hill, Aug. 9, 1910; shaft-house destroyed, machinery ruined, and upper part of shaft damaged; damage, $25,000; no cause given. Belmont Mine fire, Tonopah, Feb. 23, 1911; fire started in winze ; 17 men killed. Giroux Mine fire, Kimberly, Aug. 23, 1911 ; fire originated iii shaft-station from unknown cause; 7 men killed, and $34,¬521 damage caused. (NOTE 1.-On June 11, 1912, some time after the present paper was written, a fire broke out in the pump-room on the 2475 station of the Ward shaft, Virginia City. This fire was caused by the short-circuiting and exploding of the starting-switch on No. 5 pump. The oil in the switch was scattered about and set fire to the timbers and laming of the pump-room. The pump-roan in charge notified the surface, and the * Professor of Mining and Metallurgy, Mackay School of Mines.

Oct 1, 1912

Shovel To further increase the efficiency in the production of their foundry sand, the American Silica Sand Co. has purchased a new and improved shovel that will be used for loading trucks at their Reynolds Pit. The [ ] new shovel will greatly facilitate winter mining operations and make possible larger winter shipments of the company's foundry sand. The Reynolds Pit is one of three sand pits in the Ottawa district owned by American Silica which produce sand that is refined for foundry use. Circle No. 1 Electric Switches The Crane Electric Co. has just announced the production of their R-1000, a new rotating limit switch designed to control the travel of any rotating device requiring interruption or establishment of electrical current after a predetermined number of revolutions. It is useful for machinery, lifts, and other power equipment. The switch is presented in a finished case, 16 gage, reinforced, with walls of sufficient strength to hold the entire mechanism and all the parts in accurate alignment. The worm gear combination has a 60 to 1 ratio, sufficient for most industrial uses. The number of revolutions can still be increased by using various combinations of driving sprockets, either on the shaft of the switch, or on the sprocket of the unit controlled by the switch itself. Circle No. 2

Jan 1, 1952

Dump Truck Kenworth Motor Truck Corp. is beginning full scale production of its new heavy-duty, end-dump earth mover, model 801, a truck engineered for earth moving under the most adverse operating conditions. Payload capacity of the Kenworth earthmover is 30,000 lb and it is over-tired for safety, flotation and high tire life. The truck's body capacity, struck measure, is 9.9 cu yd, with heaped [ ] load at 11.9 cu yd. The earth-mover has a full anti-friction bearing mounted, power assisted steering gear, simplified controls, minimum turning radius and wide axle track to insure ease of handling, maximum maneuverability and high stability. The offset cab of the Kenworth visibility for the driver, before and after. Circle No. 1 Safety Equipment A compact, safe, and efficient valve assembly approved by the United States Bureau of Mines for use with MSA air line respirators, abrasive masks, and abrasive helmets has been developed by Mine Safety Appliances Co. The new MSA continuous air flow control valve regulates air flow from a compressed air source to an operator using respiratory protective air line equipment. Three parts-a centridge container, a cartridge and the air flow check valve-comprise the entire assembly of the control valve. A position action adjustment knob on the cartridge container regulates the amount of air flowing to the operator. The valve can be detached from the air line instantly by pressing the trigger on the cartridge container near the check valve. As the trigger detaches the hose, the spring loaded ball-type valve, which is attached to the end of the hose, automatically stops the flow of air. Circle No. 2

Jan 1, 1952

Jan 3, 1976

A 2-year moratorium on accreditation of curricula bearing new designations has been declared by Engineers' Council for Professional Development at its Executive Committee meeting on July 29, 1952. Reason: a more definitive description of what the contents of a curriculum should include to be appropriately designated as "engineering" is needed. This action was brought on by the Committee of Evaluation of the American Society of Engineering Education which had become perturbed over the extension of the name "engineering" to numerous fringe curricula. The 2-year period will permit time for the Committee on Evaluation to study the question and make a recommendation for further action by ECPD. ECPD action also provided that the following curricula should only be given provisional accreditation for one year upon either inspection or reinspection; such provisional accreditation to be extended annually for not more than two successive years pending the report: Engineering Physics, Engineering Mechanics, Geological Engineering, Geophysical Engineering, and Textile Engineering. There are 22 such curricula now accredited.

Jan 1, 1952

By C. K. Gupta, P. K. Jena

Niobium (columbium) metal in the form of a button has been produced by calciothermic reduction of niobium pentoxide using sulfur as the heat booster. In these experiments with 50 g of niobium pentoxide per batch, the influence of percentage of calcium in excess of the stoichiometric, the percentage of sulfur by weight of the niobium oxide, and the outer-wall temperature of the bomb on the quality and yield of the metal has been studied. The maximum yield on this scale was 78 pct using 50 pct excess Ca and 20 pct of S and at a bomb-wall temperature of 600°C. In experiments conducted on 500 g of niobium pentoxide, reduction with 40 pct excess Ca and 20 pct of S, and at a bomb-wall temperature of 500°C, the.yield of the metal improved to 82 to 84 pct. Some of the reduced-metal samples have been electron-beam melted and the button melts thus obtained have been observed to be extremely ductile and capable of cold reduction to 98 pct without intermediate annealing. NIOBIUM, because of its high melting point (2468oC), its ductility, its resistance to corrosion especially in liquid metals, its high-temperature mechanical properties, and its relatively low capture cross section (1.1 barns) for thermal neutrons, has potentialities as a structural material in the field of nuclear engineering. Niobium and its alloys are also gaining importance in high-temperature technology as components in aircrafts, jet engines, and missiles, electronics, chemical engineering, and surgery. In 1904 Weiss and Aichel 1 produced niobium by reduction of its pentoxide by misch-metal. Since then a large number of investigations have been carried out for the extraction of niobium from its compounds. The various routes through which the metal niobium has been extracted from its compounds can broadely be classified into the following groups: a) reduction of its halides, oxides, and fluo-salts with metals like calcium, magnesium, sodium, and aluminum;2-10 b) reduction of its halides with hydrogen and oxides with carbon or carbides;11-18 c) electrolytic winning from its halides and fluo salts;19-25 and d) thermal decomposition and disproportion ion of its halides26-30 Among the processes in commercial use at present are sodium reduction or fused-salt electrolysis of potassium niobium fluoride, carbide or carbon reduction of the oxide, and hydrogen or metallothermic reduction of the chlorides. In 1907 Von Bolton2 prepared niobium by reducing niobium pentoxide with aluminum. Dennis and Adam-sona attempted reducing the oxide with magnesium powder in argon atmosphere and the resulting metal contained as much as 5 pct O. Mondolfo8 claimed a method for the reduction of the oxides with aluminum. In the case of both magnesium and aluminum reduction, it has been stated31 that by-product oxides such as MgO or A12O3 would involve a major separation problem. Further, in the case of alumino-thermic reduction, the solubility of aluminum in niobium and intermetallic formation have to be reckoned with. In 1922 Bridge3 produced niobium by calcium reduction of niobium pentoxide. Dennis and pdamson' obtained the metal by a similar method with an oxygen content of 0.2 pct. In most of the cases of metallothermic reduction of niobium oxides mentioned above, the metal niobium is obtained in the form of powder. In an attempt to produce massive niobium metal, lock' used iodine as the thermal booster in the bomb reduction of niobium pentoxide by calcium. Massive niobium metal was obtained with a maximum yield of 75 pct containing 0.1 pct 0. Joly32 carried out experiments on calcium reduction of niobium pentoxide on a 2-kg scale using sulfur as the heat booster in a sealed bomb filled with argon. In his experiments, the reaction was initiated by passing a current through niobium spiral wire embedded in the charge. In a typical run consisting of 2000 g of niobium pentoxide, 3100 g of calcium, and 800 g of sulfur (S/Nb2O5 = 3.3), he obtained massive metal in the form of a very uneven mass with a yield of -57 pct. With lower amounts of sulfur and calcium, powder niobium mixed with small metal globules was obtained and the yield was also poor. From these experiments he concluded that this method is not a suitable one for industrial development considering the quality and yield of metal obtainable and the possible hazards with higher ratios of sulfur to niobium pentoxide in the -~charere. In the present work, a detailed investigation on the calciothermic reduction of niobium pentoxide in a stainless-steel bomb in presence of sulfur as the heat booster was undertaken on a laboratory scale.

Jan 1, 1964

New Products Equipment

Jan 1, 1951

New Products Equipment

Jan 12, 1951

New Products Equipment

Jan 9, 1951

New Products Equipment

Jan 4, 1951

New Products Equipment

Jan 4, 1953

New Products Equipment

Jan 7, 1951

New Products Equipment

Jan 7, 1950

New Products Equipment

Jan 5, 1951

New Products Equipment

Jan 3, 1953

New Products Equipment

Jan 5, 1953

New Products Equipment

Jan 3, 1951

By A. STEPHENSON

EXPERIMENTAL work conducted at the Petroleum Engineering Laboratory of the University of California by L. C. Uren, J. Domercq, Jr., and J. Mejia has shown that small diameter wells offer tremendous resistance to the flow of fluids in their immediate vicinity. This resistance is due in part to the constriction of the area through which the fluids must pass as they approach the wall of the well, but is also accentuated by the increased volume which results from gas expansion. The latter in turn is a function of the deduction in pressure, the fundamental cause of fluid movement. If the diameter of the bore is enlarged several diameters, the capacity of the well, or the volume of fluid passing per unit drop in pressure per unit of time, is greatly increased without necessitating such high fluid velocities. The fundamental features which should be taken into consideration in the design of casing joints were stressed by J. B. Graham and E. E. Smith. These involved such points as correct thread design, high efficiency, and small diameter, together with the insurance that leakage will absolutely be prevented. The practical features of such design were ably discussed by engineers from leading steel manufacturers.

Jan 1, 1935

New Products Equipment

Jan 6, 1951

New Products Equipment

Jan 11, 1951