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By A Purchase, C Stacey

The procedure for operation of deluge systems installed in road tunnels is still a subject of debate. The work undertaken in this paper assists in the understanding of the effects of deluge in road tunnels, and thus aims to help inform the development of operational policy. Analysis was undertaken using computational fluid dynamics (CFD) simulations to help explore the deluge interaction with the tunnel ventilation (including smoke exhaust) and combustion products. It was found, for the scenarios considered, that: Deluge activation can decrease the required critical velocity for smoke backlayering, and this in turn can improve the effectiveness of a smoke exhaust system.The dominant parameter for deluge effectiveness is the vehicle configuration, with shielded scenarios (such as a fire in the passenger compartment) showing almost no water reaching the fire. The water delivery rate (5 mm/min versus 10 mm/min) has only a minor effect on the smoke duct damper inlet temperatures and downstream smoke temperatures for small fires (5 MW). For large fires (50 MW) the higher water delivery rate gives slightly improved performance (lower damper inlet temperatures and lower downstream smoke temperatures). A one-dimensional transient tunnel model incorporating different operational and deluge response policies (ie deluge activation times) was developed. It was used to examine the influence of different operational parameters on life safety risk and tunnel damage risk. It was found, for the scenarios considered, that: The life safety risk for different scenarios has a sensitivity to deluge activation policy with the case of delaying the deluge activation for a long time giving the worst outcomes. However, the most critical parameters for life safety risk are operator response time (for all response activities, not just deluge) and the type of fire (configuration, size and growth rate).There is a reduction in risk of tunnel damage when the deluge is activated earlier, although the fire configuration (ie whether or not the seat of the fire can be reached) has the greatest influence on the outcome. It is concluded that the deluge activation policy should be case-dependent. It will depend on the tunnel, the safety systems provided, and most particularly the vehicles involved. The current policy in Australian tunnels is for manual activation of the deluge by the tunnel operator as soon as practical after the fire is confirmed (see also PIARC, 2007). This is a good policy. However, future work may be helpful to improve the skills of operators to make the best judgement as to when deluge should be activated, balancing all risks. This work could include research to further the understanding of deluge and fire in road tunnels, training programs and consideration of historical fire events.

Jan 1, 2008

By Denys B. Smith

Electric logs and cuttings records from Zechstein 3 and 4 strata in boreholes in the British Sector of have been interpreted in the light of numerous cored boreholes through this sequence in north-east England. This interpretation shows that potash salts in the two cycles are thickest and most consistent in a belt 20 to 40 km wide parallel with and a few kilometres from the present basin margin, and are here generally similar in grade to those known onshore. The potash ores in both cycles are mainly of sylvinite in onshore areas, the layered Upper the Southern North Sea Potash of the fourth cycle being rather less variable but generally of appreciably lower average grade than the Boulby Potash of the third cycle. Potash salts in both cycles are highly variable in thickness and grade in basin centre areas where they have been grossly affected by diapirism of the thick second cycle salts.

Jan 1, 1978

Boiler-Room Economy "Establishing and Maintaining Boiler-room Economy" is the title of a paper presented before the Ohio Society of Mechanical Electrical and Steam Engineers by Geo. H. Gibson, of which the following is an excerpt: Boiler-room economy depends less upon equipment than upon operation, i.e., it depends largely upon the condition in which the apparatus is maintained and how it is used. A given boiler may operate this week with an efficiency of 78 per cent., and next week with an efficiency of 65 per cent., while using the same fuel and developing the same rating. If there are variations ii; character of fuel and in load and other factors, the falling-off may be even greater, possibly to less than 60 per cent. The steam produced may cost twice as much per 1,000 lb. at one time as at another. Most steam plant managers know from their own experience that these statements are not exaggerated. It does not take much of a plant to run up a coal bill of $5,000 per year, many "spend $10,000 for coal, and fuel bills of $50,000, $100,000, or $200,000 per annum are not uncommon. As it call be shown in the majority of these plants that 10 per cent. of this amount may be saved, and in large numbers of them 25 per cent., while in some the expenditure can be cut in half, there is no disputing that we have here a subject worthy of attention. In the production of steam the greatest variable is the human factor. Before we can pass judgment, however, we must first have standards. This implies accurate quantitative knowledge of fuel consumption and steam production. We must measure the output and know how much the steam costs per thousand pounds, and how many pounds of steam are obtained from a pound of coal. We can then begin to analyze the problem, and find where and how methods and conditions can be improved, and how much. Many favor buying coal on a B. t. u. basis. This is advisable where the amount purchased warrants the considerable expense involved in systematically gathering samples that: are. truly representative and in having analyses made, of every carload. Coal analyses, combined with. an honest endeavor on the part of the miner to ship good coal, should insure the receipt of the heat units paid for. , It often happens, however, that the coal which is cheapest on a B.t.u. basis is not the cheapest or most suitable for producing steam, because of peculiarities of the plant in which it is to be burned, or conversely, the fuel which furnishes cheap B.t.u. may require special methods or equipment for its economic utilization.

Jan 2, 1916

By Harold L. Lovell

The extensive heterogeneity of coal is a fact long recognized by scientists and engineers. However, until recent years the practical implications of such heterogeneity have more often been realized from an undesirable experience than from knowledge or forethought. Variations in the properties of coal, even within the same seam, eventually lead to procedural modifications in mining, handling, preparation and utilization. The concepts considered here propose an enhanced application of information, detailing these properties, realizing the uniqueness of any given coal seam but the practicality of a common approach. Coal preparation practice has been designed primarily for the control of ash and sulfur content to meet market specifications which are similarly specified, Other physical characteristics of size and friability are also commonly employed and, to a lesser extent, properties which are implications of rank. The consideration of petrographic data as indicators of origin, thus total physical and chemical properties, has generally been overlooked as a realistic tool in-the exploitation of coal as a resource. The evolution of descriptive techniques, whether petrographic, physical, or chemical, capable of universal application with any rank of coal, is still beset with problems.

Jan 1, 1968

By S. R. Reddy

Thennodynamic properties of several quaternary systems are calculated using our recently modified Margules equations. The modified Margules equations are expressed up to infinite order in the vicinity of solvent. Quaternary system of one solvent and three,solute partials are derived. First order interaction coefficients of binary, ternary and cross -interaction parameters of quaternary system are used to'evaluate the partial functions. In the original fonn of Margules equations,derived partial functions are convergent and same 'as Unified ,Interaction Parameter Fonnalism. But considering up to infinite order of the Margules coefficients, the functions are divergent, in order to overcome this restriction, Margules equations are modified to get consistent equations. Derived partial functions are thennodynamica Hy consistent with Maxwell and Gibbs Duhem relations. The derived logarithmic activity coefficient of the solvent and solutes are consistent with the ternary systems. The calculated data, ie., activity coefficient values of nitrogen and interaction coefficients are in good agreement with the data of Fe-Cr-V -N. Fe-Ni-V -N, Fe-Cr-Ta-N and Fe-Ni-Ta-N systems.

Jan 1, 1999

By Howard Eavenson

SOME time ago, in a conference considering the mechanizing of a group of mines, I was asked if I knew of any data showing the relative frequency of accidents due to the use of 275 or 550-volt current inside mines and having a recollection of seeing some in print, the answer was made that I would find what was available. Subsequent search failed to find any pub-lished records of any kind giving such figures and none of the compensation agencies of whom inquiry was made were able to supply any, excepting the Pennsyl-vania Compensation Rating and Inspection Bureau, which had some data covering a few months for some companies in that State. The inquiry was confined to the three largest producing States, Pennsylvania, West Virginia, and Illinois. The inspection departments of neither of the first two had any such records, and in Illinois, only 275 volts has been allowed inside the mines for many years. A laborious inquiry has resulted in the data, shown in Table 1, which on this account was confined to the years 1921 and 1925, the latter being the latest figures available. In each State, to find the mines using 275 and 550-volt current respectively, it was necessary to list the mines from the Coal Catalog, and then to complete the list by inquiries from the companies directly, from Operators' Associations and from Inspection Depart-ments. As the mines not electrified, and those using

Jan 5, 1928

By I Testrow, M Wiggin

Scrutiny of the whole explosives industry has increased as a result of the terrorist attacks on the World Trade Centre and the Pentagon on 11 September 2001 and the bombings in Indonesia, including the Bali bombings last year. This has been highlighted in specific press releases from governing bodies, like the Department of Mineral and Petroleum Resources û Western Australia, on the necessity of being in compliance with regulations for storage of explosives. As a result, audits by inspectors to assess compliance are to be expected. In a proactive move, DynoConsult has assisted several customers through benchmarking current practices, in order to identify any areas of non-compliance to the statutory requirements for explosive storage and security. This paper discusses the outcomes of supplier discussions and customer audits and highlights the implications for the industry.

Jan 1, 2003

By J. Oyunaa, P. Munkhbaatar, A. Sarnai

"The molybdenum mining process used at Mongolia Erdenet Company is a selective flotation of molybdenite from the copper porphyry ores in which the extraction of molybdenum comes as a byproduct of the ongoing copper production.The mineralogical composition of molybdenum concentrate is 99.4% molybdenite (MoS2), 0.09% molybdenum oxide (MoO3), 0.52% powellite (CaMoO4) and wulfenite (PbMoO4) and content 47.76– 47.92% molybdenum, 1.5–2.67% copper, 0.04% renium.From compared solvents sodium and carbonate and ammonia are like extracted molybdenum than hydrochloric acid, which contained 96.23–97.72 p.c. of its total amount. Hence to take into consideration abundance, cheap and suitable for analysis and processing the molybdenum concentrate ammonia is choosing as a basic solvent. By direct evaporation of ammonia extract solution, we obtained ammonium ortomolybdate, which contains 73.47% MoO3. INTRODUCTIONMolybdenum occurs in the earth’s crust in an abundance of about 10–14%, mainly as molybdenite, MoS2. Small quantities are also associated with other metals having similar chemical properties. Thus wulfenite (PbMoO4) is found in oxidized parts of sulfidic lead deposits in many regions of the world; powellite [Ca(Mo,W)O4] is a calcium molybdate usually formed from the modification of molybdenite in deposits containing tungsten as scheelite (CaWO4) and tungsten substitutes for molybdenum up to about 10%. Ferrimolybdite (Fe2Mo3O12·8H2O) is the product of oxidation of molybdenite in the presence of iron (III) compounds. Molybdenite is the primary source of molybdenum. Should demand for molybdenum rise so that additional sources become necessary, wulfenite, powellite, and ferrimolybdite may become commercially significant. Molybdenum ore is mined by underground and open-pit methods. A typical primary molybdenum ore body contains 0.05–0.25% Mo, and secondary ore bodies (copper porphyry ores) average 0.3–1.6% Cu and 0.01–0.05% Mo. Flotation remains the preferred and almost exclusive method of upgrading the molybdenite mineral to an industrial-grade molybdenite concentrate containing 90–95% MoS2, the balance being gangue (Habashi, 1997)."

Jan 1, 2016

By Rodrigo Jerez

This paper describes a Mixed Integer Linear Programming model that was developed for planning the coal operations at Mountain Coals, Inc., in Kentucky. The model incorporates the use of stockpiles as practiced and allows the operator to find the least cost combination of raw coal feeds, washing densities and blending to produce the different quality coals as required by the coal contracts.

Jan 1, 1984

By Roderick K. Davey

The objective is to develop a short-range mining plan which satisfies management and operating criteria and also "dovetails" with the long-range mining plan. In the past years, this objective was accomplished entirely by manual methods. Today, the computer is used to assist the engineer with this task. The results provided by these programs usually are incomplete and require further manual manipulation. The advantage of using the computer programs is that the program can be used to evaluate alternative plans on a first-cut basis minimizing the manual work. Subsequently, the most promising alternatives can be analyzed in more detail, commencing with the first-cut results. In this specific case history, one technique for using computer programs to assist with short-range mine planning will be discussed. Some of the basic operating and management criteria considered directly and indirectly are as follows: (1) operating criteria which include minimum and maximum shovel cut size, equipment performance, haulage roads, requirements for blending, and plant capacities; and (2) management criteria which consist of production requirements, cash flow requirements, return on investment, market demands, and availability of capital.

Jan 1, 1979

NEW MEMBERS The following list comprises the names of those persons who became .members during the period of Jan. 10, 1918, to Feb. 10, 1918. ANTISELL, TONER, Min. Engr.; Supt., Great Falls Mine of Maryland, Chevy Chase, R: F. D. No. 4, Washington, D. C. BAKER, RAYMOND FRANK, Geol:, The Texas Co., Producing Dept., Box 362, Tulsa, Okla. BERTON, ADRIEN, Chief Engr., Corocoro United Copper Mines, Ltd., Corocoro, Bolivia. Buck, WILMER EARLE, Met., Curtis & Co. Mfg. Co., Hamberger & Kienlein Aves., St. Louis, Mo. BUELL, WILLIAM H., Asst. Director, Experimental Station, E. I. duPont de Nemours & Co., Wilmington, Del. CARDENAS, FEDERICO F., Mgr., Cia. Minera Nazareno y Alicante, S. A., Allende, No. 112, Saltillo, Coah., Mexico. CHEVALIER, JEROME A., Pet. Geol., The Carter Oil Co.; Exchange National Bank Bldg., Tulsa, Okla. CLEAVES, DANIEL LUNT Supt., St. Joseph Lead Co., Herculaneum, Mo. CLOTHIER, GEORGE A., Resident Min. Engr., Province of British Columbia,

Jan 3, 1918

By S. E. Bretherton

THIS title introduces the subject I wish to describe to my fellow members, very few of whom, I hope, have ever had as much trouble with the smelting of ore containing much zinc, either in the lead blast furnace or the matting furnace, its circumstances have forced upon me: First, for several years in Leadville, Colo., after the sulphide ores containing zinc had been developed with greater depth and were sold to the interests with which I was connected for smelting in the blast furnace for the recovery of the lead, silver, and gold; then, in New Mexico and Arizona, where the principal source of ore supply for our custom smelter was from miners who sent most of their product in the form of concentrates, which we briquetted and smelted in the blast. furnace, producing a matte containing copper, silver, and gold, for which we were paid; together with some zinc and lead, which was penalized if in excess of a maximum base set by the refinery to which we sold our copper matte; last, but not least, my experience in Shasta county, Cal., where for the sake of recovering $13 per ton value in copper, silver, and gold, I have smelted ore containing as high as 40 per cent. zinc (the last. 18,951 tons smelted averaged 15 3/10, per cent. zinc) which we not only lost, but which it cost us money to lose.

Jan 8, 1913

Jan 1, 1910

By L. T. Sicka, H. N. Thomson

The Tooele plant of the Internationa1 Smelting & Refining Co. is situated at the mouth of Pine canyon, Tooele county, Utah. It is connected with the main line of the San Pedro, Los Angeles & Salt Lake railroad by the Tooele Valley railway, and is about 7 miles from Tooele Junction. Fig. 1 is a general view of the plant. The copper plant has been in operation since July, 1910, arid the first blast furnace at the lead plant was blown in on Feb. 29, 1912. The location of the plant was selected on sloping ground with the idea of using gravity to the fullest extent and thus keeping labor at a minimum. Practically the entire plant is constructed of steel, reinforced concrete, and brick. Bingham ores, both lead and copper, are received over the Utah Consolidated Aerial Tramway. The tram buckets, each containing

Jan 1, 1914

For effective backfilling, a system with the 13 features covered under the section: effective backfill systems, is required. Effective backfilling cannot be done with systems that are badly designed, outdated or overextended. But in cases where the requirements for effective backfilling are overlooked, the shortcomings of such systems may wrongly come to be regarded as limitations to the capabilities of backfilling per se. Mining is currently done to depths of 3500 m, and is to go deeper since the gold-bearing reef extends down to 4000 m and 5000 m below surface. Effective backfilling systems will be required at such depths, and with suitable design this can be achieved. Mining the narrow tabular orebody of a typical South African gold mine is described at the start of this paper, then cycloned backfilling is discussed in general, and its effectiveness (most of the fill placed in South Africa is cycloned backfill or ædeslimed tailingsÆ).

Jan 1, 1998

By S R. Grano

The selection of the proper frother, specifically for a given ore, is essential in flotation. Traditionally, strong and stable froths are required in the scavengers, where metal recovery needs to be maximised, while selectivity must be achieved in the roughers and cleaners, where grade of concentrates is the main issue. The physical properties of a froth are determined both by frother type, by process water composition and by the amount and nature of the suspended particles. The evaluation of different frothers, in terms of metallurgical performance, is complicated at plant scale, since it may lead to periods of malfunctioning of the process and unacceptable decreases in recovery. On the other hand, evaluation based on frother chemistry only, is often unsatisfactory, because the frothing response is strongly ore dependent. A procedure, and proper tools, was developed at the Wark in order to perform the screening of candidate frothers at batch scale on real pulp samples. The main parameters related to froth stability (half-life time, froth height) are measured after introducing the pulp samples into a foaming column, where different conditions in terms of frother addition, agitation and aeration can be maintained. The approach has been applied to the selection of frothers for the flotation of an Australian sulfide ore. Procedure and results are discussed.

Jan 1, 2006

By Bjorge, Guy N.

MINING method improve through the gradual process of evolution and in 1340 there were no marked outstanding innovations. On the other hand refinements of detail and betterment: in equipment design continued to progress. Among the most important changes have been the increased application of trucks and highway equipment, including tractors and bull- dozers, to open-pit mining as exemplified by Phelps Dodge's Morenci operations; the Mesabi iron range; and the Tri-State district. Mass or bulk handling contributed its part underground with slurhers and conveyors at Consolidated Coppermines and slushers at Climax; and in open-pit mining. conveyors found increased use on the Mesabi range.

Jan 1, 1941

By A. B. Kinzel, Walter Crafts

A PRevioUs study1 of the relations of impact strength to inclusions showed that the dynamic strength of steel is lowered by the presence of visible counted inclusions, but that other factors comprised in the term "body" have a marked influence. The previous work was carried out on selected steels from a single source, so that the body factor was purposely minimized, but even under these conditions it was found that inclusion counting or the use of the commercial inclusion rating is not satisfactory. The tensile-impact test, however, was indicated as a satisfactory measure of dynamic strength. It was further suggested that the tensile-impact test should be so standardized as to be suitable for use in specifications, and that the hardness factor should be worked out over a sufficient range to admit ready commercial use of the tensile-impact test. In accordance with these suggestions, and in view of the fact that the steels reported in the previous paper were selected and treated so as to have a minimum variation in body, hardness and structure, further work has been performed on a variety of steels which are not limited by these conditions. The word "body" is used here for want of a better term. It is simply a convenient expression which comprises the effect, of the various unknown factors that modify the dynamic strength of the steel. Thus at our present state of knowledge, the writers have chosen to consider hardness, structure and counted inclusion content as factors not comprised in the term "body," and such factors as raw materials, process of melting, fabricating, etc., as comprised in the term "body." Numerous grades of steels made in several ways have been taken from different sources and have been heat-treated to varying hardness by normalizing and by quenching and drawing. The results, therefore, may be considered to be generally applicable to current engineering steels. A certain limitation with respect to the hardness at which steel should be tested still seems necessary. The upper limit of this hardness range has

Jan 1, 1931

By R. Kingman

At Tahawus, New York, National Lead Company operates the MacIntyre Development, This operation produces 10,600 long tons of ore per day for crushing, 8,000 tons for grinding and processing, of which 2,000 tons per day reports as tailing for disposal in an impounded tailing storage area. With the change in location of mining operations at the mine of National Lead Company, a change in the area for tailing disposal by gravity became necessary, This called for the diversion of tailing from near the proposed mining area to areas more favorable for long term storage by gravity. In order to avail the operation of maximum storage for the future, a uniform minimum grade launder was proposed with a minimum velocity and maximum outfall at the discharge. Disposal of the gravity and flotation tailing was formerly accomplished in open ditch from the concentrator at a grade of 1.5 percent. It was desirable to design the new launder at grades less than this for the greater storage elevation.

Jan 1, 1966

By John Stankus

Seam interaction in multiple seam mining has significant effect on entry stability. The remaining pillar in an old working usually creates a high stress concentration zone while the gob creates a stress release zone. A good panel layout should take advantage of the stress release effect created by old workings. This paper presents two case studies of multiple seam mining. The Jennmar Finite Element Analysis System (JFEA) is utilized to analyze the seam interaction effect and identify the mess concentration and relief zones Panel layouts are designed bad on the results of the finite element analysis Appropriate roof support system are also designed for different seam interaction areas.

Jan 1, 1999