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By Robert F. Shurtz

When an ore deposit is evaluated on the basis of core sampling, questions always arise as to how much weight should be given the various sample grades and how the deposit should be divided into specific volumes assigned to corresponding grades. For a tabular deposit it is customary to use the so- called zone-of-influence. This zone is usually de- fined as the polygon in the plane of the deposit having corners halfway between a given core drill intersection and each of the nearest neighboring intersections. The volume of the ore in this polygon is assigned the analysis obtained from the drill core taken at the intersection. In massive or irregular deposits, volumes of various shapes may be defined with respect to the locations of drill core samples. These volumes may be regarded as three-dimensional zones-of-influence; the theory involved in assigning the values of the central analyses to the ore in the volumes is the same as that used in the case of a tabular deposit. The zone-of-influence method was used in evaluating one of the magnesite deposits at Gabbs, Nev.1-3

Jan 10, 1959

By John Brennan

The Avalauncher has been an integral tool for avalanche mitigation work for close to 50 years. With their ability to place a kilogram of high explosives up to two thousand meters away, they routinely serve as a short range alternative to military artillery. The Avalauncher’s roots can be traced to a pneumatic baseball pitching machine used by Major League Baseball teams in the United States in the late 1950s. Throughout the decades, many modifications have been made to both the launcher and its projectiles. Current technology has allowed the Avalauncher to attain greater accuracies and operational range. In this paper I plan to cover not only the history of the Avalauncher but also explore its potential future.

Jan 1, 2009

By M. L. Whisman

Several commercial processes for reclaiming used lubricating oil were duplicated on a laboratory bench scale. Laboratory tests were selected and in some instances modified to determine the physical properties of each oil produced. In addition, the hydrocarbon composition of some samples was determined using a liquid chromatographic technique, and compared with the composition of new oil in order to determine the severity of the re-refining technique. Selected samples of reprocessed oil were reformulated with an additive package for further estimates of quality as determined by wear, corrosion, foaming, and oxidation stability tests. Additionally, several samples of commercially re-refined oil and new oil were obtained and physical properties were determined for comparative studies.

Jan 1, 1974

By F. L. D. Cloete

The following discussion relates to the paper by G. S. Hansford, C. D. Levy, and J. W. de Kock that appeared in the March 1976 issue of the Journal (vol. 76, no. 8, pp. 363-369) Competition for student members Each year the South African Institute of Mining and Metallurgy offers a prize (or prizes should the entries warrant it) of up to RI00 for the best paper or dissertation on a topic appropriate to the interests of the Institute. Engineering in South West Africa The SW A Engineering Profession Steering Committee was established on 4th April, 1977, its purpose being to formulate an Act covering the engineering profession in South West Africa.

Jan 1, 1978

ORANGE FREE STATE BRANCH Proceedings of the Annual General Meeting The Annual General Meeting of the Branch was held in the St. Helena Club on Tuesday, 3rd October, 1972 at 8.00 p.m. Mr J. M. Meyer was in the chair. METALLURGISTS AND COMPUTERS An address delivered at the Annual General Meeting of the O.F.S. Branch by Prof D. D. Howat. Most men who remain in mining and metallurgy like their jobs. There are many times when you say to yourself or to your wife - 'Anybody can have my job - if they want it'. You feel so fed up and frustrated everything that could go wrong has gone wrong.

By William R. Hart

I was this morning an interested listener to the remarks of Mr. Ashbel Welch in regard to his designing a new section for steel rails, in 1866; and for the salze of the truth of history, and in order t:, give the credit to an American (and where it rightfully belongs) of higning the first section for steel rails, which was intelligently adapted to that material; I beg to state the following facts: On the 14th of August, 1866, Mr. Ashbel Welch gave me an order for 200 tons of steel rails, to be made bbr the Camden and Amboy Railroad, from a section designed by him. A copy of this section 1 append herewith.

Jan 1, 1881

By Gary A. Almeraris, Thomas F. Peyton

This paper describes the innovative procedures employed during the construction of 3 deep shafts within the confines of New York City. The shafts, which varied in diameter from 1.8m (6ft) to 7.3m (24ft) and had an overall depth of 199m (650ft), were excavated by both mechanical and conventional methods. These were subsequently concrete lined, clad steel riser pipes installed and associated surface structures were constructed. Tricky surface rock blasting coupled with the unearthing of unexpected obstructions caused constant uncertainty during the excavation phase. In addition, the necessity of handling men and material in restricted yet deep openings required the development of a safer and more productive shaft construction procedure.

Jan 1, 1989

By W. M. Duncan, F. S. Kendorski, C. V. Jude

After shotcrete had been in use for a short time al the Climax Mine of the Climax Molybdenum Co., Climax, Colo., it was noted that regular longhole undercutting blasts would severely damage or detach slusher drift shotcrete linings. If this were to be a usual occurrence, the widespread application of shotcrete would have to be reexamined or abandoned. Concrete drift linings are affected less by blasting because of occasional significant gaps between the placed concrete and rock and the greater thickness of poured-in-place linings. Research Project Organized A research project was organized to determine: 1) the seriousness of the problem, 2) more complete in-use shotcrete strength data, and 3) possible solutions.

Jan 12, 1973

By R. J. Gochin, M. A. Diaz, M. L. Court

Single impact breakage tests have been carried out on samples of alumina in carefully controlled atmospheres consisting solely of nitrogen gas and water vapour. The results indicate a statistically significant increase in the surface area of the progeny particles as relative humidity rose to 50%. The majority of this increase was found to occur under conditions when adsorption was a monolayer or less. The results are consistent with the theory of surfactant-induced strength reduction of materials proposed by Rehbinder and Westwood. There are important implications where single impact tests are used as part of a design methodology for comminution machines. In most procedures relative humidity has not been a controlled variable.

Jan 1, 1995

Alternatively are they a necessary evil'? Exploration geologists are a much higher profile group but then again the higher they are the bigger they Bill. At a mine site they are reluctantly being accepted as equals by mining engineers given the requirements of the `Code' in the reporting of Ore Reserves. How best can mining geologists service their customers? Are more revealing questions to be answered in who are their customers? In the past mining geologists lived isolated existences pouring over plans and sections, now with user-friendly software packages available and the use of LAN, mining geologists and mining engineers talk electronically - God forhid what the future might hying - they might even talk to accountants and metallurgists!

Jan 1, 1997

?Energy-related systems: wind, solar, electric are typically materials intensive. As new technologies are widely deployed, significant quantities of the elements required to manufacture them will be needed. However, many of these unfamiliar elements are not presently mined, refined or traded in large quantities, and, as a result, their availability might be constrained by many complex factors. A shortage of these ?energy-critical elements? could significantly inhibit the adoption of otherwise game-changing energy technologies. This, in turn, would limit the competitiveness of the U.S. industries and the domestic scientific enterprises and, eventually, diminish the quality of life in the US.? -Energy Critical Elements: Securing Materials for Emerging Technologies?- American Physical Society, 2011.

Jan 1, 2012

By Scott G. Giltner, Terry Millar, Ben Bringhurst

"Kennecott Utah Copper (KUC) Smelter scheduled a rebuild of their flash smelting furnace forSeptember, 2014. KUC’s goal in this project was to reduce the rebuild time from 65 to 55 days by using explosives to break the matte and brick layers of the uptake shaft and hearth sections of the furnace. Previous rebuilds had employed the slower technique of mechanical breakers to remove the matte and brick layers which took 22 days. KUC has many years of experience in removing slag from the uptake shaft, but they had never used explosives to remove the hearth. As far as KUC was aware, no other smelter operation had attempted a hearth removal in this way."

Jan 1, 2016

By S. R. B. Cooke, H. S. Choi, I. Iwasaki

In magnetic taconite of the East Mesabi range, quartz, magnetite, and cummingtonite (OH}(Fe, Mg)(Si4O11)2) are the three major ore-forming minerals.' Fine grinding and magnetic separation of the taconite leads to a concentrate analyzing 64 to 65 pct Fe and 8 to 9 pct insoluble; the gangue content of the concentrate arising from the presence of locked magnetite-gangue particles, and of occluded gangue particles in magnetic floccules. To further upgrade such taconite concentrates, flotation appears to offer a particularly promising approach. To evaluate its effectiveness in separation, a knowledge of the flotation characteristics of each mineral comprising the concentrate becomes desirable. The floatability of magnetite and of quartz have already been reported in a previous paper,2 in which the flotation characteristics of the two minerals were correlated with the electrokinetic properties at the mineral-solution interfaces. Since cummingtonite has somewhat intermediate chemical composition between the above-named oxides, the electrokinetic and the flotation behavior of this mineral becomes of interest for both practical and fundamental reasons. In the present article the results of electrophoretic mobility measurements and of Hallimond tube flotation tests on cummingtonite are reported and are compared with those of quartz and magnetite. MATERIALS AND METHODS A sample of cummingtonite-rich taconite, received from the Mitchell pit, near Babbitt, Minn., was crushed and ground through 100 mesh, and the product was fractionated magnetically into three portions. First, a drum-type laboratory cobber was used to separate a highly magnetic portion, consisting mainly of free, but also containing locked, magnetite particles. The cobber tailing was then passed in two stages through a Franz isodynamic separator. The middle fraction was isolated, and, upon examination petrographically, was ascertained to be principally cummingtonite. The 100 to 150 mesh fraction of this sample was selected for the present study. It was cleaned by leaching briefly with hot, dilute HC1 and then by rinsing repeatedly with demineralized water. A ground and elutriated fraction of -5p cummingtonite was used for the electrophoretic measurements.

Jan 1, 1961

By J. E. Emmerling

The Federal Bureau of Mines investigated dust suppression obtained with three different water-spray nozzle systems during underground continuous coal mining at the face. The nozzles were the "regular" nozzle normally used by the mine, and high-efficiency and low-efficiency nozzles selected on the basis of an airborne capture theory of respirable dust by spray drops. The high-efficiency nozzle used one-third less water than the others throughout the testing. Results depended on the type of cutting operation at the face. The sump-downshear operation appeared to involve a significant amount of capture of airborne respirable dust. The same amount of dust was measured when using the high-efficiency and regular nozzles. The dust levels when using the high-efficiency nozzle were about 20 pct less than those measured when using the low-efficiency nozzle. The sump-upshear operation seemed to involve a predominance of other aspects of dust suppression, such as impaction of spray drops onto the face. Compared with the downshear operation, there was a significant reduction in dust levels for a total face operation when using the regular nozzle; dust levels when using the regular nozzle were about 15 pct lower than those measured when using the high-efficiency nozzle.

Jan 1, 1975

By Hong Zhong, Shuai Wang, Gang Zhao, Lanqing Deng, Guangyi Liu

In this paper, three novel surfactants containing double reactive centers(-CONHOH and –CONH-), double hydrophobic groups were designed and synthesized as collector for separation of diaspore and aluminosilicate minerals, such as N-(4-(hydroxyamino)-4-oxobutyl)octanamide (HA-8), N-(4-(hydroxyamino)-4-oxobutyl)decanamide (HA-10) and N-(4-(hydroxyamino)- 4-oxobutyl) -dodecanamide (HA-12). The adsorption mechanism of N-(4-(hydroxyamino) -4-oxobutyl)alkylamides (HA) onto diaspore was also investigated by FTIR spectra, zeta potential measurement and DFT. The flotation results demonstrated that three collectors all exhibited superior collecting power to diaspore and selectivity against kaolinite and illite, and could effectively realize flotation recovery of diaspore from bauxite ores contained aluminosilicate minerals under neutral conditions. Moreover, HA-12 was a superior collector than other two collectors for bauxite separation. The results of XPS, FTIR spectra and zeta potential illustrated that at around pH 6.0, HA might chemisorb on diaspore surfaces through Al-O coordination bonds formed by binding its –C(=O)NHOH or –C(=O)NH– chelate groups with aluminum atoms on diaspore surfaces. HA’s unique properties, such as characteristic bond patterns onto diaspore surfaces, double hydrophobic groups, and intermolecular hydrogen bonds between neighboring HA molecules coated on diaspore surfaces, rendered it to be a superior flotation collector for diaspore.

Jan 1, 2016

By J. W. Harden

APART from the merits of the respective systems of mining under conditions alike, there is much in the nature of the coal and the measures with which it is associated, to make that system which is successfully practiced in one locality ill adapted to that of another; the structure of the coal itself, the roof, the floor, the depth and character of the overlying strata, each exercising more or less controlling influence. Again, in the highly bituminous districts, and with such as have caking coals, where the size of the coal as it comes off the face does not affect its value, as the very smallest of it may be utilized, and in the hard, the open and free-burning coals, in some of which the round only (large coal) is merchantable,

Jan 1, 1873

The fall meeting of the. Institute of Metals Division will be held in Philadelphia on Sept. 30 to Oct. 2. All meetings will be held in the Ritz-Carlton Hotel, Broad and Walnut Streets, which is also the hotel headquarters. As this meeting is being held in conjunction with the meeting of the American Foundrymen's Association, the members of the Institute will have the privileges of the exhibit of the Foundrymen's Association. This, it is expected, will be one of the largest exhibits made in this country. On Monday evening, Sept. 29, there will be a meeting, in the Ritz-Carlton Hotel, of former officers and members of the Executive Committee of the Institute. It is requested that all officers and Committee members, the present as well as the past, will arrange to be present.

Jan 8, 1919

The fall meeting of the Institute of Metals Division Will be held in Philadelphia on Sept. 30 to Oct. 2. All meetings will be held in the Ritz-Carlton Hotel, Broad and Walnut Streets, which is also the hotel headquarters. As this meeting is being held in conjunction with the meeting of the American Foundrymen's Association, the members of the Institute will have the privileges of the exhibit of the Foundrymen's Association. This, it is expected, will be one of the largest exhibits made in this country. On Monday evening, Sept. 29, there will be a meeting, in the Ritz-Carlton Hotel, of former officers and members of the Executive Committee of the Institute. It is requested that all officers and Committee members, the present as well as the past, will arrange to be present.

Jan 9, 1919

By Victor F. Hollister

This report summarizes data available on the Fort Knox gold deposit to the end of 1989. It is presented courtesy of Fairbanks Gold, operator of the Fort Knox mine. The ore body and the data base are being expanded in 1990, but this summary is pertinent for inclusion in a case history volume that, in part, stresses porphyry-type deposits. Fort Knox is a pluton-hosted gold deposit 22.5 km (14 miles) northeast of Fairbanks, AK. It is easily accessible from Fairbanks, and ultimately it will be the largest open pit gold mine in Alaska. The Fort Knox pluton has an interesting historical record, and it has been discovered at least twice. Fig. 1 shows the geology and location of major plutons in the Fairbanks mining district.

Jan 1, 1991

By J. W. Harden

APART from the merits of the respective systems of mining under conditions alike, there is much in the nature of the coal and the measures with which it is associated, to make that system which is successfully practiced in one locality ill adapted to that of another ; the structure of the coal itself, the roof, the floor, the depth and character of the overlying strata, each exercising more or less controlling influence. Again, in the highly bituminous districts, and with such as have caking coals, where the size of the coal as it comes off the face does not affect its value, as the very smallest of it may be utilized, and in the hard, the open and free-burning coals, in some of which the round only (large coal) is merchantable,