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By W. H. Fluker

Until recently, the universal practice in New Zealand was dry-crushing and direct cyaniding. With ores containing no mineral sulphides, and little or no coarse gold, 'this method, in spite of its many disadvantages, gave excellent results, and was by far the best one available, pending the solution of the slimes-problem. But the situation has now been changed. The successful treatment of the slimes, enabling the mines not only to do away with dry-crushing, but also to deal with the mineralized ores of the lower levels, which are, for obvious reasons, quite unsuited to that method of treatment, has made wetcrushing universal; and this may be taken as satisfactory proof of its superiority over the former practice. In the lack of accurate information from plants operating successfully, particulars of experimental trials carried out on a working-scale at the Waitekauri Extended mine, Maratoto,

Jan 1, 1903

By Jack Parker, Bert Caverson

More than 6000 resin-anchored bolts have been installed at the White Pine mine, and their performance has proven excellent in both pull tests and "beam" building. With its improved reliability, resin anchorage will permit a more scientific approach to the design of roof bolting systems, and this should ultimately result in both better support and reduced costs. The White Pine mine lies five miles south of Lake Superior in Ontonagon County. Mich. The orebody occurs in gently dipping upper Keweenawan sediments midway between the Porcupine Mountains and the Bergland Hills, both of which are ranges of steeply dipping Keweenawan extrusives and intrusives.

Jan 1, 1971

The volumes of Transactions, which are published annually, contain the list of officers, rules, etc., the Proceedings, and the papers revised for final publication. (In this revision, after the preliminary publication, authors are permitted to use the largest liberty; and the changes and additions made in papers are sometimes important. It should be borne in mind by those who study or quote a paper in the preliminary edition, that they may not have in that form the ultimate and deliberate expression of the author's views. It should be added, however, that in the majority of cases there are no important changes.) These volumes are for sale as follows, in paper covers:

Jan 1, 1910

The volumes of Transactions, which are published annually, contain the list of officers, rules, etc., the Proceedings, and the papers revised for final publication. (In this revision, after the preliminary publication, authors are permitted to use the largest liberty; and the changes and additions made in papers are sometimes important. It should be borne in mind by those who study or quote a paper in the preliminary edition, that they may not have in that form the ultimate and deliberate expression of the author's views. It should be added, however, that in the majority of cases there are no important changes.) These volumes are for sale as follows, in paper covers:

Jan 1, 1910

By T. A. O’Hara

SINCE May 1948, when tungsten carbide bits were introduced at the Flin Flon mine, they have been popular with the miners because of their fast drilling speed and low gage loss. The high cost of commercial carbide bits and tipped drill steel, however, prevented their use except for the hardest rock. In an effort to extend the use of tungsten carbide on a basis economically competitive with detachable steel bits, experimental work was begun in 1950 to test the feasibility of making tungsten carbide tipped drill steel in the mine drill steel shop. This work showed that tipped drill steel could be made locally at less than half the cost of the commercial product. The performance of the local tipped drill steel was comparable to that obtained with commercial carbide bits and tipped drill steel and the cost per foot drilled was much lower.

Jan 3, 1954

By Charles O. Thompson

In 1867 the city of Worcester walled in the Mill Brook for its main sewer. This stream, one of the important affluents of the Blackstone River, flows through the city in a southwestenly course from Salisbury Fond, and along its valley a considerable part of the heavy manufactories of the city are placed. At two points, a mile apart, a sufficient fall occurs to be turned to account for motive power, and at many points it was the right and practice of the riparian proprietors, prior to 1867, to use the water for steam and other manufacturing purposes. But the

Jan 1, 1881

By J. B. Czirr, E. P. Palmer

In an effort to improve coal-mine safety, a spectrum analyzer was used to make a detailed examination of the vibration frequencies produced by tapping a mine roof. We show that spectral analysis can be used to distinguish between "solid" and "drummy" roofs to a degree approaching that of the human ear, but it can reveal little about roof-slab thickness or attachment. We recommend research into the utility of augmenting human hearing in roof testing and into utilizing microseismic emissions to help assess roof integrity.

Jan 1, 1983

By Edward J. Bagnall

The major raw material feed properties of size distribution and chemistry are examined in relation to their effect on sinter operating conditions, plant productivity, sinter physical quality, reduction- degradation characteristics and sinter texture and mineralogy. The resultant physiochemical properties of these sinters are related to their behaviour in subsequent ironmaking operations.

Jan 1, 1977

By Rudyard Kipling

Through the courtesy of the British Museum of Natural History we have received a copy of an address delivered by Rudyard Kipling at Folkestone, Feb. 15, 1918. We take pleasure in reproducing it in full, because its sentiments are just as appropriate here and now as they ever were. If you will allow me. I will tell you a story. Once upon a time, a. hundred years ago, there was a large and highly organised community in India who lived by assassination and robbery. They Were educated to it from their infancy; they followed it

Jan 9, 1918

By John A. Riddle

Some of the pitfalls and problems in selecting and applying corrosion-resistant materials in uranium plants are discussed, together with some suggested solutions. Includes some cost data.

Jan 1, 1982

By Irvin Mayes, Maher E. Tadros

The effects of particle properties and dispersion on the filtration behavior of magnesiumhydroxide, silica, and polystyrene suspensions in aqueous media were examined. It was found that effective separation of particles can be achieved using filter media with larger pore diameters than the size of the particles. The addition of electrolytes, at concentrations lower than the critical coagulation concentration, to suspensions of polystyrene or silica resulted in an increase of the cake resistance. This result was interpreted in terms of a decrease in the effective particle size due to the increase in ionic strength. For magnesium hydroxide, an increase in the absolute value of the surface charge was associated with an increase in cake resistance and a decrease in cake compressibility. Low cake resistance values were obtained with suspensions of large particles with low surface charge and blocky morphology.

Jan 1, 1980

Jan 1, 1916

By AIME AIME

MANY years ago when the writer chaperoned a group of student officers from Wright Field on their re- quired inspection trip through the Mid- dletown plant of American Rolling Mil1 Co., Leo Reinartz was our guide. After the party had watched continuous strip being rolled and was ready to move on we ventured a remark-to emphasize the difference between Armco iron and automobile fender stock-that this strip was ordinary steel. The remark was overheard by our guide and the effect was instantaneous; in a rather re- proachful tone Leo said: "Gentlemen, your teacher has been in this plant many times, and he should know by now that we, in this company, never make ordinary steel-all of our prod- ucts are the highest possible quality."

Jan 1, 1943

Executive Committee. CHESTER F. LEE, Chairman. C. R. CLAGHORN, Vice-Chairman. WC. BUTLER. M. K. LODGERS. Joseph DANIELS, Secretary-Treasurer. Meeting, Jai. 25, 1913.-Dean Milnor Roberts read a paper on The Equipment and Curricula of the College of Mines, University of Washington.

Jan 4, 1913

By Byron Pickard

AT MIDNIGHT of Sunday, Aug. 27, 1922, a fire was discovered in the main shaft of the Argonaut mine, Jackson, Cal. With the excep-tion of a shift boss and two skip tenders who escaped, the entire night shift of 47 men was trapped in the mine and entombed for 22 days, when the bodies were recovered. The entombed miners made a valiant but fruitless effort to save their lives. Rescue crews toiled strenu-ously day and night for 21 days to save the entombed men, only to find they had arrived too late. From the experiences of the entombed miners and of the rescue crews, valuable lessons may be learned to prevent future catastrophes.

Jan 11, 1922

By C. W. Schulties, W. J. Mallio, L. J. Petrovic, J. A. L. Campbell

Roof control comprises about 35% of direct and indirect underground mining costs. In addition, difficulties in estimating roof control costs for new areas lead to the greatest uncertainties when negotiating coal contracts. And obviously, coal cannot be mined if the roof can't be held. Accordingly, there are strong incentives to attack this problem on as many fronts as possible. One successful geological modeling technique for predicting future roof conditions was recently applied at Peabody Coal's Simco mine No. 5, located in Coshocton, Ohio. Benefits derived from it included: - A better identification of areas where poor safety conditions may be encountered. - Improved roof control cost estimates for contract negotiations. - Estimates of time-duration while mining in bad roof areas. - Labor and materials cost predictions in an existing mine. - Productivity increases through prior knowledge of areas to avoid.

Jan 10, 1975

By Paul A. Bailly

“For innovative leadership in bringing about a quantitative rationality to mineral exploration; for the impact his efforts and wide respect have made on national mineral policy issues; for his effective managerial role in major mineral discoveries; and for his lecture, ‘Managing for Ore Discoveries.’”

Jan 1, 1980

MEMBERS-QUALIFICATIONS AND ELECTION SEC. 1. The membership of the Institute shall comprise seven classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members; 7. Junior Foreign Affiliates. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall he entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which be must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members. SEC. 3. Honorary Members: Each candidate for Honorary Membership must be recommended by at least ten Members and must be elected by ballot at a meeting of the Board of Directors by the unanimous vote of the Directors present; provided, however, that the number of Honorary Members shall at no time exceed twenty. Such election shall automatically act as a transfer of such member from any other class of membership to which be may belong.

Jan 1, 1938

By A. M. Nicholas

WHEN attempting to lift mill pulp containing a considerable percentage of wolframite, in an ordinary bucket elevator, difficulty was encountered from the tendency of the tungsten minerals to settle, on account of their high specific gravity. Lifts not exceeding 20 ft. (6m.) could be accomplished without particular difficulty, because there was insufficient time for consolidation of the heavy minerals in the bottom of the bucket; but with higher lifts, the heavy tungsten minerals would settle so solidly that when the bucket turned over at the top of the elevator the contents could be only partially dumped. In this case it ,was necessary to lift the material a distance of 34 ft. (10m.); hence some means had to be adopted to prevent settling, at least to such an extent that the material could be dumped from the buckets. To reduce the carrying time to a sufficient extent would have required a belt speed of 475 ft. (144.7m.) per minute, which was not feasible. It was decided to try, by vibrating the belt about midway of its span, to keel) the material sufficiently agitated during elevation to prevent settling. Underneath the rising side of the belt was placed a 12-in. (30.48-cm.) idler pulley, 18 ft.-(5.5 in.) up in the total lift of 34 ft. The idler pulley was set eccentric by 3/4 in. (19 mm.) and it was hoped that the vibration thus imparted to the belt, running at a speed of 280 ft. (85 m.) per minute, would prevent settling in the buckets. It was found that the pressure of the belt on the idler, due to the small inclination of the elevator, was not sufficient to overcome sliding on the idler, and the agitation was insufficient to accomplish the desired purpose. The idler was then connected to the drive shaft of the elevator through an intermediate pulley, gearing down to a speed of 20 r.p.m., so that a positive vibration was imparted to the belt; this imparted enough motion to the belt to prevent settling and the contents of buckets clumped satisfactorily.

Jan 2, 1918

By W. A. Boyer, A. W. Beck

At the Morning mine of American Smelting & Refining Co. it was particularly important that there be a means of signaling the engineer from the moving cage in the shaft. Because of the shifting ground in which the shaft was located, buckling timber made it extremely difficult to keep a continuous bell line serviceable. In 1930 engineers considered a moving contact pantograph arrangement between the cage and two stationary messenger wires strung on insulators in the shaft compartment next to the cage. The idea was abandoned because falling material in the shaft and speed of hoisting made it difficult to maintain communication. Later in 1934 a manufacturing company was consulted about the use of an electric eye or a radio signal. As the shaft was located in a return air stream of nearly 100 pct relative humidity, there was too much fog for the electric eye to be used. The radio signal was considered, and it was believed feasible to generate electric static on the cage, locating a radio receiver at the top of the shaft, but the manufacturing company's research department was too busy to work on it at that time.

Sep 1, 1955