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By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION The investigation of the general hazards of combustible gases and vapors in manholes owned by the Edison Electric Illuminating Co. and the study of methods for eliminating these hazards, conducted by the Bureau of Mines, the Edison Electric Illuminating Co. of Boston, and the Boston Consolidated Gas Co. since 1929, was continued during 1933.From May and through December 1933 these tests were supplemented by a study of the manholes of the New England Telephone & Telegraph Co. The test crew was under the direct supervision of John Campbell, superintendent of the Special Service Department of the Edison Electric Illuminating Co., and F. M. Goodwin, vice president of the Boston Consol¬idated Gas Co.The procedure of sampling manhole atmospheres and of shipping the samples to Pittsburgh was the same as that used heretofore. In previous reports the relative explosibility of the samples was calculated by adding the percentages of the illuminants, hydrogen, carbon monoxide, methane, and ethane, dividing the total by 6.5, and multiplying by 100. Experience has shown that the factor 6.0 is more nearly correct; therefore, this has been used in calculating the relative explosibility of all the samples listed in appendix A and B of this report. If gasoline vapor is present a smaller factor must be used.ACKNOWLEDGMENTSThe cooperative investigation was arranged through the interest and effort of W. C. Bayliss, president of the Edison Electric Illuminating Co. of Boston; W. C. Beckjord, vice president and general manager of the Boston Consolidated Gas Co., and A. C. Fieldner, chief engineer, Experiment Stations Division, United States Bureau of Mines. Thomas H. Haines, superintendent, Distribution Department of the Edison Electric Illuminating Co., cooperated heartily in furnishing both men and information for the work."

Oct 1, 1934

During 1995 a catastrophic accident took place at the No 2 Vaal Reefs shaft in South Africa, when a locomotive fell onto a cage, causing the death of 104 people. The subsequent Commission of Enquiry found that the safety detaching hook had opened when hit by parts of the falling locomotive, detaching the cage from the rope and allowing the cage to drop 400 m down the shaft. It was believed that had the hook not detached, the rope would have been sufficiently elastic not to have failed, implying that many fatalities may have been avoided. In addition, the risk of accidental opening of hooks due to impact with smaller falling objects in shafts became a concern. This paper deals with a comprehensive statistical investigation that was performed to quantify this risk, establish acceptable levels of such risks and to derive criteria for the resistance of detachment hooks against accidental opening caused by impacts. The investigation involved a survey, dynamic finite element analyses and Monte Carlo simulations.

Jan 1, 2005

By G. S. Scott

Mine fires have occurred since the mining of coal was begun, and they are still occurring. The resulting economic waste may become considerable (219),3 especially if a fire is allowed to assume major proportions or to get beyond control temporarily. It is important, therefore, to act promptly whenever a fire is suspected and to have every action count. To do this effectively, it is necessary to know at the earliest possible moment and thereafter what is happening in a remote or inaccessible area. It is equally important to know before¬hand what may be expected as a result of any proposed combative measure. The logical method of combatting a fire demands the cooperation of both mining engineer and chemist. They should decide the course of action to be taken, drawing upon the mining engineer's intimate knowledge of the physical structure of the fire area, the cost and time required for proposed operations, and the probable efficiency with which they could be carried out, and upon the chemist's knowledge of the results to be expected therefrom.

Jan 1, 1944

By Mathias Woydt

The tribological and mechanical properties of binderless and metal-bonded niobium carbides (8 or 12 vol.-% of Cobalt, 12 vol.-% of Fe3Al) are presented. Rotating disks made of niobium carbide bearing hard metals were mated against alumina (99.7%) under unlubricated (dry) unidirectional sliding tests (0,1 m/s to 12,0 m/s; 22°C and 400°C) as well as in oscillation tests (f= 20 Hz, ?x= 0,2 mm, 2/50/98% rel. humidity, n= 105/106 cycles). Microstructure and phase compositions were determined as well. The tribological data obtained were benchmarked with different ceramics, cermets, hard metals and thermally sprayed coatings, where NbC bonded with 8% and 12% Co presented above 8 m/s the lowest wear rates so far in such a benchmark. Binderless NbC (HP-NbC1) and the metal bonded NbCs exhibited low wear rates under dry sliding associated with high P?V load carrying capacities. NbC-based hard metal bonded with 12 vol.-% of Fe3Al resulted in a higher hardness level than for 12 vol.-% cobalt. The tribological profile established revealed a strong position of NbC bearing materials under tribological considerations and for closed tribosystems against established reference tribo-couples.

Jul 31, 2018

By Y Chung, B Choi, H Lee

Numerous studies have explored refractory corrosion in the presence of slag and/or metal, utilising the Finger Rotating Test (FRT). Recent experimental results revealed that corrosion initially increased with rising rotation velocity but was then suppressed above a critical rotating speed, under conditions involving a two-liquid solution of slag and molten steel. This phenomenon indicated that the liquid/liquid interface movement occurred during spindle rotor. However, understanding of the phenomenon, known as the rod climbing effect, remains inadequate in the case involving slag, molten steel and refractories. To gain deeper insights, a simulation experiment was conducted on the phenomenon using silicon oil/water and the phenomenon was analysed using computerised simulation software (Ansys Fluent). Experimental modelling demonstrated that interfacial movement occurs even at low rotation velocity, as low as 200 rev/min, when the viscosity of silicone oil is at 100 cP. Computational analysis utilising the Volume of Fluid (VOF) method and a realisable k-ε turbulence model elucidated that interface elevation during rotor rotation arises due to viscosity disparities between the two fluids. Furthermore, this movement is more pronounced when the viscosity difference is lower. Additionally, the study findings suggest that higher density differences between two liquids suppress the phenomenon of interface movement.

Jun 19, 2024

By AIME AIME

TWO days of solid discussion, with barely time out for meals, characterized the Tulsa meeting of the Petroleum Division. It was preeminently an earnest gathering devoted to technical matters. Sessions were held in the Crystal room of the Mayo Hotel with luncheon served each day in the back of the same room so that talk of methods, while slightly less formal, extended right through the lunch hour. Thursday evening the Committee did provide a little relaxation in an informal dinner at the Tulsa Club where, after a brief musical program and an amusing skit by the local Herman the Great, brief addresses in non-technical vein were made by President Farish and Vice-president Rice of the Humble Company, Henry L. Doherty of Cities Service, Secretary. Bain of the Institute, and others. The presence of leading executives of a number of the oil companies at the dinner and the sessions, and the cordial approval they expressed of the work of the Division were especially gratifying. The total registration was 215 with 100 at the dinner and 70-to 80 lunching together each day.

Jan 1, 1930

By D. H. Newland

CERTAIN observations from the field and laboratory suggest the need for recasting some of our ideas about gypsum as a rock-forming mineral and in relation to supplies for industrial use. Until about 25 years ago, the use of gypsum was confined almost entirely to agriculture. During the past quarter century, though, its usefulness has been greatly developed, particularly in the building trades, which now absorb most of the gypsum produced. In 1919, according to the U.S. Geological Survey, the output of crude gypsum was 2,240,163 tons, a gain of 912 per cent. in 25 years. About one-half of this production was mined in New York, Ohio, and Michigan, where the proved supplies can hardly be regarded as over-large when viewed in relation to the rapid expansion of industrial requirements. The occurrence of gypsum in the United States is treated by R. W. Stone and others.1 The deposits of Canada are described by L. H. Cole.2 Several states, including Kansas, Oklahoma, Iowa, Michigan, and New York, have had special surveys made their of gypsum deposits, but the reports, as a rule, refer to conditions as they existed from 15 to 20 years ago.

Jan 9, 1921

By Tim Langmaid, Steve Skelhorn, Stephanie Robillard, Allen Mitchell

"The Port Mann Main Water Supply Tunnel project provides a critical water main crossing of the Fraser River for the owner, Greater Vancouver Water District (Metro Vancouver). The project consists of two 60-metre-deep slurry panel shafts and a 1-kilometre-long, 3.5-metre excavated diameter tunnel located near Vancouver, British Columbia, Canada. The initial tunnel lining is a precast concrete steel fiber reinforced gasketed segmental lining. The final lining is a 2.1-metre-diameter welded steel pipe. This paper describes the challenges encountered during tunnel construction and the solutions implemented. Key challenges include earth pressure balance tunnelling at up to 6 bar pressure—the highest to date in Canada—a water-crossing without surface access for the majority of the tunnel drive, ground freezing from a river platform for a critical TBM intervention, and boring through cobbles and boulders in dense glacial till. INTRODUCTION Metro Vancouver supplies drinking water to 18 municipalities, one electoral district and one treaty first nation, serving a population of more than 2.4 million residents. Water is collected in three mountainous watersheds to the north of the Greater Vancouver area, in southwestern British Columbia, Canada. To supply the growing demands of Metro Vancouver’s customers, treated water must be conveyed across two significant water bodies: the Burrard Inlet and the Fraser River. The existing Port Mann water main is one of several key links between the watersheds north of Vancouver and the municipalities south of the Fraser River. The Port Mann Main Water Supply Tunnel (PMMWST) is the first of a series of upgrades, to increase capacity, enhance scour protection, and improve seismic resilience. The new tunnel is 3.5 metres (11.5 ft) in diameter and 1 kilometre (0.6 mi) long. When completed, it will contain a new 2.1 metre (7 ft) diameter steel water main that will help ensure the continued, reliable delivery of drinking water to these municipalities, and will more than double the capacity of the existing 1.2 metre diameter main."

Jan 1, 2016

By Lloyd A. Morley

Research performed on computer modeling of mine power systems under USBM Grant G0155003 1S described. The work was performed at the Pennsylvania State University from 5 November 1975 through 4 November 1976. Results presented are interim in nature, and future research is planned to integrate the simulations which have been developed. The thrust of this research has been divided into three main areas. 1. Modification of a previously developed model (Mine Power System Simulation or MPSS) to include interactive operation and the use of default (average) load data. 2. Development of a dynamic simulation of interdependent mine power system induction motors. 3. Development of an approach to modeling of motor shaft loading of induction machines for mining operations. During the course of the current year's research, significant results have been achieved in all areas. Construction of an interactive MPSS model has been completed and checked. This simulation was written in APL code and is fully interactive. In addition, default data representing 158 different pieces of mining equipment has been developed for use with the interactive model. Additional work described includes the construction of a dynamic simulation of interdependent continuous miner induction motors and the development of an approach fo: motor shaft load torque computation from experimental data.

Jan 1, 1976

By R Lau

In recently completed road tunnel projects in Queensland, such as the Airport Link and the Clem7 tunnels, there is a smoke duct running along the roof of the carriageways to extract smoke in case of fire. In New South Wales, no road tunnels have a smoke duct. In the Melbourne City Link tunnels, there is a small smoke duct running along the roof. All of the tunnels are safe as claimed by the designers and authorities. However, there is significant cost associated with providing a full size smoke duct compared with no smoke duct. This paper is going to present a comparison of the road tunnel safety with a smoke duct and those without one from a risk perspective. It further discusses the cost-effectiveness of such provisions and whether similar levels of safety could be achieved without a smoke duct.CITATION:Lau, R, 2014. Smoke duct or no smoke duct for road tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 83–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Albert F. Schneider

The peculiar conditions under which lead and silver ores are now smelted in Salt Lake Valley, Utah, render it advantageous to make slags that are siliceous and carry a high percentage of lime. The ores treated come from Utah, Idaho, Montana, and Nevada; nine-tenths coming from Utah. These ores are siliceous, and contain but little fluxing material; the iron present scarcely sufficing for the sulphur and arsenic. Formerly ores high in iron were furnished from Cottonwood Canons, but this supply is meagre. The ores from Idaho, Montana, and Nevada are high grade galenas, more or less impure. They generally require a large amount of iron for the sulphur, arsenic, and antimony. In the winter and spring of 1880—'81, we were treating at the Germania Works principally Bingham Canon lead ores and silver ores from Tintic. The former contained 15 to 30 per cent. silica, and only 4 to 5 per cent. iron (generally as iron pyrites); they ranged high in lead and low in silver, and carried more or less alumina; the lead was present chiefly as carbonate. The silver ores from Tintic contained sulphides, and ran as high as 80 per cent. silica. We had been running on a slag approximating 40 per cent. FeO, 20 per cent. CaO, 10 per cent. other bases, and 30 per cent. SiO2, which had heretofore been very satisfactory; but with the class of ores then coming in it was of the utmost advantage to use less iron and more lime, especially as the iron ore (50-55 per cent. iron and 5-7 per cent. silica) cost four times as much as the limestone (50-55 per cent. lime, 3-5 per cent. silica). The large amount of alumina in the slag influenced them for the worse; the addition of lime to the charge helped them, and after many experiments regarding the proportion of FeO, CaO, and SiO2, a slag approximating 35 per cent. FeO, 25 per cent. CaO, 5 per cent. other bases, and 35 per cent. SiO2 seemed to answer

Jan 1, 1883

By Mihir B. Roy

"Coal transported by rail for Thermal Power Plant in Haldia, West Bengal, India, was to be received and stored in Coal Complex comprising of Wagon Tippler, Track Hopper, Junction Houses and network of horizontal and inclined tunnels. The site was very soft with high ground water level. Deep excavation and dewatering posed great difficulty. Original plan was to drive about 1000 m of steel sheet pile and well sinking which had major impact on cost and time. High ground water was identified as the main problem. Controlling water level and maintaining it would allow open excavation over major areas. Scheme for lowering aquifer with one and two-stage well-point dewatering system was developed following basic principles of groundwater and seepage. Arrangements of wells, installation and pumping were worked out in detail. Water levels could be lowered below bottom levels of excavation. Design of sheet pile was modified under lowered ground water condition. Overall length and depth of sheet pile were reduced drastically. Open excavation was possible in segments over major areas. The scheme was highly successful in smooth and fast progress of underground works. The works were completed safely months ahead of schedule time and with significant saving in cost.INTRODUCTIONThe Coal Receiving Complex of thermal power plant comprised of 250 m long 8 m deep Track Hopper (TH), 12 m deep Wagon Tippler (WT) with provision for addition of another Wagon Tippler. Track center lines of TH and WT were very close. Coal unloading facilities were connected with a network of underground tunnels and Transfer Points (TP) upto Pent House (PH). The facilities were optimized in a compact layout within about 400 m x 120 m area. Initially excavation for TH was started adopting side slope of (1 V : 1.5 H) with 2 m wide berm and dewatering by in-pit sump and pump. When depth of excavation reached about 5-6 m, failure occurred over a long stretch as shown in Figs. 1a - 1b photos. Further work was stopped to develop scheme for carrying out deep excavation and civil works safely."

Jan 1, 2015

By Kristine Bruce Wanderley, Denise Crocce Romano Espinosa, Jorge A. Soares Tenório

Mining of nickel ores generates large volumes of waste that must be removed in order to eliminate water contamination and reduce environmental impacts created by waste barriers. In this context, the need for innovations concerning the recovery of magnesium present in the liquor produced by the leaching of nickel laterite with sulfuric acid arises. Therefore, this work aims to develop a study regarding the crystallization of magnesium from a synthetic liquor solution using a batch autoclave system at high temperature. Agitation speed was kept constant at 1000 rpm throughout the 3 h of batch reaction for temperatures of 230 and 200 °C. Aliquots taken at each hour were analyzed by ion chromatography to measure magnesium concentration. The highest magnesium removal was observed for temperature 230 °C. X-ray diffraction (XRD) and scanning electron microscopy (EDS-SEM) analysis proved that the product formed was magnesium sulphate monohydrate crystals. Thermogravimetric analysis coupled with a mass spectrometer was used for the evaluation of the thermal stability of magnesium sulphate monohydrate. It was found that MgO and SO2 were formed by the decomposition of the salt at 1100 °C.

Mar 1, 2017

By P. K. Fedotov

At projecting mining-concentrating complex at the deposit ?Zapadnoye? (Russia) it was considered to enable an opportunity of refusal from conventional SAG-mills. First time a scheme of gold bearing ore destruction using Roller Press RP 5-100/90 had been developed and integrated. The plant was launched in summer 2003 and presently it has achieved designed technological parameters, processing throughput comes to 1 million tons of the ore per year.

Jan 1, 2014

By J. A. Snyder, W. L. Finlay

SEVERAL notable studies of the effects of sub- stitutional solutes have been reported. Outstanding among these for its elucidation of general principles, is the summarized work of Hume-Rothery and coworkers.1 For a systematic study of the effects of substitutional solutes on the mechanical properties of the solvent lattice, the work of Brick, Martin, and Angier² on copper; of Frye and coworkers³,4,5 on copper and silver; and of Lacy and Gensamer6 and of Austin7 on iron may be mentioned. Titanium is one of the few elements offering the possibility of a similar study of interstitial solutes since, unlike most metallic elements, it exhibits extended solid solubility for most of the interstitial solutes—hydrogen, boron, nitrogen, oxygen, and carbon. This paper reports a survey of the effects of dilute solutions of nitrogen, oxygen, and carbon on the mechanical properties of high-purity alpha titanium. Previous Work: Van Arkel and De Boer showed" that high purity titanium was quite ductile and De Boer, Burgers and Fast established".' that not only were oxygen and nitrogen very soluble in solid titanium but that, long before the limit of solid solubility of either had been reached, these interstitial solutes rendered the metal brittle. Their electrical resistance data as a function of

Jan 1, 1951

By Donald G. Oss

The need for instrumentation and automatic control of the various parameters in the heavy media process of iron ore beneficiation has been apparent for some time. Continued demands for higher grade, competitive products from the Mesabi Range have made it necessary to increase the efficiency of the process in every possible way. A brief review of a typical heavy media flow scheme, as illustrated in. Figure l, might be in order for those not intimately associated with this process of iron ore beneficiation.

Jan 1, 1962

Fifty to 75 million years ago, hydrocarbon-bearing rocks were formed in the Green River formation of Colorado, Wyoming and Utah. The hydro- carbons can be extracted from these rocks, marl- stone but misnamed oil shale, after crushing and intense heating. At about 900°F the marlstone decomposes to produce liquid shale oil. A press release from the Colony Development Co. describes a process which may permit, for the first time, economically feasible access to shale oil. Shale oil has resisted economic extraction for almost three centuries. According to the USBM, a patent was issued as early as 1684 in England to produce "oyle from a kind of stone". France produced oil from marlstone in 1838 and a dozen years later, Scotland started an oil shale industry, producing kerosine, that lasted nearly 100 years. In both countries, the process involved crushing the stone and retorting it to decompose the kerogen-a long and costly process at that time. In 1859, Edwin L. Drake brought in the first oil well in Titusville, Pa., and shale oil faded into oblivion.

Jan 8, 1965

By S. S. Clarke

THEN sufficient ore has been blocked out on a lease to warrant a shaft, the proposed. Location of the shaft should be carefully considered, as the old promoter's method of sinking wherever his hat landed is a sad mistake as some: of us have learned by trying to operate such mines. In some instances certain conditions exist, such as mill location, railroad right of way, etc., that necessitate a change of location from the. ideal, but under average conditions and with the knowledge of the formation gained from the drill logs and with the general trend of the orebody known, the shaft can be located from. the standpoint of its future relation to the mine with re-gard to hauling and' hoisting a maximum tonnage: at a minimum cost per ton, also taking into account the minimum amount of expense and trouble- in sinking. Quite a few shafts are located in the wall of a run or just in the thin edge of the orebody: As a general rule the formation here is solid and permits rapid and safe sinking, and the shaft pillars are left in practically valueless material. This permits the withdrawal of pillars and still keeps the shaft protected. By opening a shaft in thin ground, you are not tempted to cut it high, wide, and handsome, but to shape it up-with ample clearance for lay-bys and with more of an idea of permanency, as a few hundred extra dollars spent around the shafts for proper track installation will re-turn, a good rate of interest in ease of handling "cans," quick get-away; and fewer wrecks. Nearly all the shafts in this district are sunk on a contract basis, the con-tractors furnishing all labor and explosives, and the company building the sinking-derrick, dump-track, and furnishing, all equipment, material, and power. The following costs are the averages, for three shafts sunk through good solid formation, with no water to, contend with, and approximately 260 -ft., deep, having about-100 ft. of shale. The contract price was $9 per foot with the shale and $13 per foot in the solid, making a total of $2,980 paid to the contractor. The wages paid by the contractor were, $5 per shift for the hoist-man, who also sharpened steel, $6 for the lead shaft man, and $5 for the helper;, the cribbing was sawed on contract for 40c. per shaft: foot; about. 94 board feet. of cribbing was used per foot of staggered cribbing and 168 board feet per foot of solid cribbing.

Jan 8, 1928

ELECTROREFINING Canadian 1,023,691 -Removal of bismuth from slime filtrate in the Betts process refining of lead. The filtrate is subjected to electrolysis in a cell having an anode of crude lead and a cathode of refined lead under operating conditions to preferentially deposit bismuth on the cathode. The substantially bismuth-free filtrate is recycled for use in the process as the electrolyte for producing high-purity lead. S. Hirakawa and R. Oniwa, assigned to Mitsui Mining & Smelting Co., Ltd. Jan. 3, 1978. 8 pp. (204-73). Filed: 2-18-74 (192,810). Same: U.S. 4,026,776, dated May 31, 1977.

Jan 1, 1979

By T. Koulomzine, R P. Jaeggin

The claims now held by Mount Wright Iron Mines Co. Limited were acquired by staking in 1956, 1957 and 1958, i.e., some time after the major deposits of the Quebec Cartier Mining and Normanvi!le Mining Co. (formerly Quebec Cobalt & Exploration Ltd.) were already discovered and partly outlined. The choice of the location of the Mount Wright hold-ings was governed simply by the -availability of ground still open to staking and by its proximity to properties held by major iron companies. Mount Wright Iron Mines had no previous knowledge of the geology and no aeromagnetic results were available to it to guide the choice of areas to be staked. In order to explore the newly ac-quired claims it was decided to make a grid of widely spaced magnetic profiles on the ground rather than use aeromagnetics. This afforded the possibility of making some geological observations simultaneously with the geophysical measurements.

Jan 1, 1961