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By Zhenfeng Zhou, Qingguo Xue, Jingsong Wang, Yingli Liu, Yuanyuan Zhang, Hailong Huo

Coal burnout strongly depends on the residence time and dispersion of coal particles in the raceway region of a blast furnace. The residence time and dispersion of coal particles are directly related to the lance arrangement. In this work, a three dimensional model was developed to simulate the lance-blowpipe-tuyère-raceway region of a blast furnace. Double lance and eccentric configurations were considered. For the double lance, the double-lance and eccentric double-lance were considered. For the eccentric double lance, the effect of intersection angle of the two lances was investigated.

Mar 1, 2017

By Keith G. Wallace, Daniel J. Brunner

The traditional approach to mine ventilation planning involved making estimates of airflows, including leakage routes, and summing the corresponding pressure drops along consecutive paths in order to determine the fan pressures required. This methodology changed completely with the availability of computers. Mainframe digital computers began to be used for mine ventilation network analysis in the mid-1960's. Their use spread rapidly throughout the world in the 1970's. Mainframe machines were employed owing to the need for high speed numerical procedures and substantial storage requirements. However, during the past decade, the growing availability of low cost but powerful microcomputers has allowed the development of net- work analysis programs that can handle ventilation systems of hundreds of branches, and which can produce results within a few minutes. This paper discusses recent advances in software and hardware development specific to mine ventilation planning. Software developments include interactive data and output manipulation, graphical representation of output, internal checks on input parameters to preset ranges and subroutines which calculate the gas distribution throughout the network from known gas sources. Hardware advances have led to significant increases in memory to facilitate the analysis of large ventilation models, math co-processor chips which greatly shorten run times, and plotter hardware for graphical output displays. Recent software developments make it possible to graphically display output on printers faster than on standard plotters.

Jan 1, 1989

By J. R. Stack, H. H. Alexander

Prior to 1915, numerous attempts were made to treat tin concentrates in the United States, but for various reasons they were unsuccessful. Tin ore is said to have been found in nearly every state, but none of the deposits has proved to be of commercial importance. An annual output of a few hundred tons in Alaska is the only domestic production; hence any considerable production of tin in the United States must be from foreign ores. The most promising occurrence of tin was found in the Black Hills, S. Dak.; in the early development stage, it was called the Cornwall of America. Associated with the tin is tungsten The story is told that an exceedingly fine specimen of the Black Hills ore was sent to England to encourage stock promotion; the desired effect was produced until a skeptic chipped off a small piece, which the analysis showed to be wolframite. First Attempts at Smelting One of the first promising attempts at tin smelting in the United States was made by R. T. White at Bayonne, N. J., in 1903. Mr. White, after spending some time in England studying the methods of tin smelting, organized a company called the International Tin Co., and erected a plant to treat tin concentrates from the Straits of Malacca. About the time the plant was completed, the English Government placed an export duty of 40 per cent. ad valorem on tin concentrates exported to other than British smelters, which duty made it impossible to operate this plant so the enterprise was abandoned, As this export duty is still effective, the only source of tin-ore supply for the United States is the Bolivian concentrates. Bolivian Tin Concentrates Unlike the alluvial placer deposits, nearly all Bolivian tin occurs in lode deposits and some of the highest grade ores contain only a small

Jan 1, 1924

By Alencar de Andrade Soares

Este trabalho tem como objetivo descrever as ações que foram tomadas pela TKCSA com o objetivo de restabelecer a capacidade operacional plena do Gasômetro (BFG), pela sua estabilidade e, por conseguinte a sua continuidade operacional. Desde seu start-up, ambos os Gasômetros apresentaram vários problemas que impediram sua operação em plena capacidade; provocaram várias paradas para realinhamento, rebalanceamento, bem como repopeamento. Estas ocorrências interferiram fortemente na Geração de energia do complexo, devido a instabilidade dos Gasômetros, causada por irregular movimentação do pistão, provocando sua descentralização e desnivelamentos fora das tolerâncias aceitáveis, o que levou a TKCSA a limitar a operação dos Gasômetros e, mesmo assim ; sempre que descentralizava e ou desnivelava, era necessário novos ajustes (repopeamento e rebalanceamento). Tais eventos nestes importantes equipamentos, levaram a CSA a tomar várias ações conforme preconiza o IGEM (Instituition of Gas Engineer) passando por reparos estruturais e culminando com a troca do sistema de selagem dos Gasômetros.

Sep 25, 2017

By Yi Zheng

Under normal circumstances, methane released along a longwall face represents only 10%-20% of the total me- thane emitted from the entire longwall panel. However, there might be a sudden surge of methane at the face which may cause a potential problem because the friction from shearer cutting, support movement, and scraper conveyor dragging can be ready ignition sources. Therefore, to predict the distribution of methane will be critical to prevent possible explosions. In this paper, methane dispersion patterns along a lognwall face are simulated under normal and abnormal conditions. With the simulation of methane released from the face, around shearer drum, and from the broken coal on the conveyor, places with possible high methane content can be identified by different phases of working process and shearer positions. Local ventilation measures are evaluated so precautionary measures can be planned ahead.

Jan 1, 2012

(Separates of all the Pamphlets published within the last three years (starting with No. 1469) are available, with few exceptions, at Institute headquarters. Separates of all the Technical Publications are also available. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found either in the TRANSACTIONS or in the special volumes issued by the Institute.] METAL MINING TRANS. PAMPHLET VOLUME NUMBER TITLE AUTHOR MEETING AND PAGE'S 1033 Relation of Air Pressure to Drilling H. W. Seamon New York 66, 743, 756 Speeds of Hammer Drills Feb., 1921 1034 Time Factor in Depletion of Mines J. W. Roberts New York 66,711 Feb., 1921 1035 Calculation of Ore Tonnage and Grade J. E. Harding New York 66, 117, 122 from Drill-hole Samples Feb., 1921 1038 Discussion of Papers Presented in 1920 1041 Run-off and Mine Drainage H. N. Eavenson New York 66, 624,630 Feb., 1921 1043 The Health of the Underground Worker A. J. Lanza New York Feb., 1021 1045 Dust-ventilation Studies in Metal D. Harrington New York 66, 272, 289Mines Feb., 1921 1046 Discussion of Papers Presented at New York Meeting, 1021 1072 Breakage and Heat Treatment of Rock- B. F. Tillson New York 66,1758 drill Steel Feb., 1921 1073 Discussion of Papers Presented at New York Meeting, 1921 1076-M Analysis of Some Drill-steel Testa F. B. Foley New York 66, 789 Feb., 1921 1077-M Application of Magnetic. Analysis to C. W. Burrows New York 66, 796 Rock Drills Feb. 1921 1078-M Heat Treatment of Rock-drill Steel G.H. Gilman New York 66, 779_ Feb., 1921 1080 What is the Ideal Drill Steel? F. H. Kingdon New York 66,807 Feb., 1921 1051 Rock Drill Steels, etc. - W. T. Ober New York 66,814 Feb., 1921 1082-C Underground Mine Development, Its J. B. Dilworth Wilkes-Barre 66,715, 7.21 Definition and Valuation Sept., 1921 1084 Drill Steel from Hollow Ingots P. A. E. Armstrong New York, 66, 809 Feb., 1921 1088 Authors' Replies to Recent Discussion 1092 Heat Treatment of Rock Drill Steel A. E. Perkins New York 66,811 Feb., 1921 1096-M Octagonal Ventilation Shaft. of Davis- J. L. Bruce Wilkes-Barre 66, 252, 268 Daly Copper Co. Sept., 1921 1100-C Determination of Electrical Equip- G. Bright Wilkes-Barre 66, 580, 605 ment for a Mine Hoist Sept. 1921

Jan 1, 1927

By Kaustubh Joshi, Pradip, Beena Rai, Kesri L. Menaria, Venugopal Tammishetti

"Beneficiation of alumina rich iron ore slimes is a major challenge for the Indian iron ore industry. High alumina is deleterious for the performance of both blast furnace as well as sintering plants. Slimes generally contain 5 - 10% alumina, and hence despite assaying as high as 60% Fe, those are dumped in tailing ponds. The slimes are typically less than 37 microns. Selective flocculation of iron ore slimes using highly selective reagents is thus an option worth exploring. Our research is directed at employing state-of-the-art molecular modeling techniques for the selection/design of selective reagents for this separation. We have earlier reported our results on starch as a selective flocculant for iron ore slimes. In this paper, we present our results on the selective dispersion-flocculation of natural iron ore slimes using guar gum flocculant. With careful selection of various process parameters such as flocculant dosage, dispersant dosage, pH and settling time, we were able to obtain a concentrate assaying >66% Fe and <3.5% Al2O3 with an yield of 65 to 68% (recovery of iron values more than 70%) from a natural iron ore slime sample assaying 58% Fe and 7% Al2O3."

Jan 1, 2014

By Gunhild Hennum, Tewodros Tefera, Gisle Håland, Annette Jahr

"Abstract The Gudrun field is located west of Stavanger in the North Sea at water depth of 109 m. A jacket substructure was selected to support the topside and was installed in 2011. The jacket shall be able to support 16 of 0.762 m (30 in) diameter conductors and is equipped with a drilling deck to allow for pre-drilling by a jack-up rig through the jacket. In general the soil conditions below mudline comprise of a thin top layer of very loose to dense sand overlaying several layers of sandy clay, ranging in stiffness from firm to hard. Below some 30 m depth the soil consists of layers of medium dense to dense silty sand overlaying very hard sandy clay containing thick beds of sand to 100 m depth or more below mudline. The jacket is secured to the seabed by twelve 2.438 m (96 in) diameter steel pipe piles, three at each pile cluster located at the four legs of the jacket at sea floor. Different design methods were used to determine the pile penetration depth. Pile drivability was evaluated using best estimate and upper bound soil parameters. The pile driving and blow count record show that the target penetration was reached as predicted. This paper discusses the different methods used to determine the pile capacity, target penetration depth and the drivability analyses made for the Gudrun jacket piles. The soil resistance during pile driving is back-calculated from the pile installation data and compared with the prediction made.IntroductionThe Gudrun platform is located west of Stavanger in the North Sea at water depth of 109 m. A jacket substructure was selected for the Gudrun platform. The general Gudrun platform jacket configuration is to a large extent dictated by the topside layout, the requirements for support points enclosing the well slots and access for the jack-up rig. The Gudrun platform jacket is a traditional 4 legged structure with a vertical side towards the jack-up rig. At the seabed the jacket is quadratic with a base dimension of 40 by 40 metres. Figure 1 shows the Gudrun jacket during load-out from the fabrication yard to the transport barge. At the site the jacket was lifted off the barge, upended and placed on the seabed by the installation vessel. The jacket is secured to the seabed by twelve 96"" (2.438 m) diameter steel pipe piles, three at each pile cluster located at the four legs of the jacket at sea floor. The target penetration of the piles is 47 m."

Jan 1, 2014

By John W. Korczak

The use of geological and grade block models has been standard practice in mine design for many years now, with a wide range of software available for creation and analysis. Although geotechnical parameters are of vital importance to mine planning there is very little in the way of commercially available systems for integrating geotechnical data into the mine planning and design process. Sirovision is a new technology developed by the CSIRO (Commonwealth Scientific and Industrial Research Organization) in Australia for automated, safe and accurate 3D mapping of geological and geotechnical features. Datamine has integrated this capability into its product range so that Sirovision has become an integral part of the day-to-day mapping, mine geology and geological / geotechnical modeling in both open pit and underground mine environments. This is the first integrated underground application of Sirovision from Datamine collaboration with Xstrata Nickel at the Nickel Rim South Project. This paper discusses the role of Sirovision in collecting the raw data required for geological and geotechnical analysis and the interpretation in a quick, safe, auditable and reproducible manner.

May 1, 2009

By H. Kurokawa

Sumitomo Metal Mining decided to expand copper production capacity of Toyo Smelter and Refinery to cope with the recent copper demand growth in Asia, and to survive by reducing cost. The expansion plan is promoted to increase electrorefined copper production capacity from 270,000 metric tons in 2001 to 450,000 metric tons in 2007. The major changes in smelting section are introduction of the rotary steam dryer, renewal of the feeding system for flash furnace, improvement of the concentrate burner, modification of the flash furnace cooling materials, renewal of the slag cleaning furnace, modification of the flash furnace waste heat boiler, installment of a new converter furnace, enlargement of two anode furnaces. In addition, the gas cleaning system was upgraded and the second acid plant was installed. In the refinery section, the existing tank houses have been operated at high current density of 300A/m2 using the conventional starting sheet cathode technology and moreover a new tank house utilizing the permanent cathode technology was constructed. Although the copper production capacity has been increased, SO2 emission has been kept the lowest in the world through consideration of influence on the environment by expansion project.

Jan 1, 2006

By W. Sondermann

"AbstractWith the increasing demand in reuse of inner city areas and the urgent need for deeper foundation pits under cramped circumstances, adjacent structures close to and high ground water level, the well-known established technologies especially with small to mid-sized dimensions are often too time consuming and occasionally not economic to install lateral support systems. The alternatives for these specific cases could be the usage of the deep mixing technology to create lateral support systems in reinforcing the deep mixing elements additionally to transfer the horizontal loads from earth – and water-pressure.With increasing demand in depth and water tightness, verticality and overlapping of single column solutions are becoming the key in execution. In addition, for some applications subsoil-conditions were not ideal for wet deep mixing technologies. The tubular soil mixing system (TSM) as a combination of mechanical mixing and support of hydraulic cutting by jet grouting can provide solutions toovercome these challenges.1. Current market conditions and trendsThe present financial crisis and the efforts not only to consolidate national budgets, but also to rescue certain banks, have not left the building industry unaffected either. Some drastic cutbacks to public budgets, along with the increasingly restrictive granting of credit for the financing of construction projects, have led to enormous over-capacities in the building sector, with purely negative impact. As a consequence of these negative developments, many companies are experiencing the pressure to restructure more quickly and to reduce costs but at the same time to keep the consequences of all activities, both externally and internally, within limits acceptable to employees, owners and finance institutions and last but not least consumers."

Jan 1, 2014

By Julian Szekely

Transport phenomena, that is heat transfer, mass transfer and fluid flow, play a critical part in the operation of metallurgical reactors. In this paper, we shall present a review of our current state of ability to model these systems mathematically, with emphasis on the use of computational codes that are generally accessible to the public and on the comparison of the theoretical predictions with measurements.

Jan 1, 1993

By O. C. Ralston

The Bureau of Mines has under development on a technical scale an electrolytic process for treating oxidized ores of zinc , using caustic soda as an electrolyte . Whereas the Bureau process can alternately make either solid zinc or zinc dust , the following paper , from the Ludwigshafen research laboratory of the well -known I. G. Farbenindustrie , A. G. , of Germany, deals only with production of zinc dust from sodium zincate solutions and may well serve as introduction to the subject for American metallurgists . The Bureau of Mines pioneered in the idea ; a study on laboratory scale by H. J. Morgan and 0. C. Ralston was made early in the First World War, and published in Transactions of the American Electrochemical Society . The Eckardt paper , translation of which follows , goes more thoroughly into the preparation of electrolytic zinc dust , and later publications of the Bureau of Mines will deal with broader details and application of the idea to treatment of lowgrade ores and metallurgical intermediates , which is the point where Eckardt left off . 4 The Eckardt report became available through operations of Field Information Agency , Technical ( FIAT ) of the Office of Military Government for Germany (US ) , which made bibliofilm copies of the files of internal technical reports of many of the German industrial establishments , Eckardt's report is dated April 1939 and was taken on FIAT Microfilm Reel MM 106 , frames 82-101 , which is on file as Publication Board Document 41411 in Office of Technical Services of the U. S. Department of Commerce , Washington , D, C , Eckardt points out that the normal source of zinc dust is the blue powder of the zinc retorts , which decreases in volume every year owing to technologic improvements in zinc smelting. I. G. saw the importance of making a

May 1, 1948

By L McCracken

Up until 1990 CoalCorp North Island&apos;s accident record was six times that considered acceptable in those NSW operations with good accident prevention programmes. This was an obvious avoidable burden on the company in both human and cost terms. &nbsp; Late in 1989 an accident prevention programme was implemented with the objective of achieving a 50 per cent&nbsp;reduction in the lost time accident frequency rate within 12 months. The key to achieving this objective was recognised as being an attitude change in the total workforce from General Manager downward. Management commitment and action were seen to be critical to the success of the programme. &nbsp; Through very basic and simple training programmes in accident investigation, analysis and reporting, communication, on-the-job coaching and in focusing on improving supervision skills, the original objective was achieved. &nbsp; During 1991 the application of methods improvement and hazard recognition techniques are seen as the logical step to achieving a further 50 per cent&nbsp;reduction in the accident frequency rate.

Jan 1, 1991

By Robert Stefanko

The importance of underground stress instrumentation cannot be minimized. It was Lord Kelvin who said that unless you can assign a number to a quantity,, you know very little about it. Most engineers will agree although this kind of statement is resented by our friends in non-technical fields. Mining is undergoing a revolution from art to science. But how can mining methods be optimized if there is no way of measuring the effectiveness of a given mining method? Do we know how effective a&apos; support is unless we can determine its reaction to the mine structure? How do we assess the need for modifications to existing systems and supports, and how do we measure the effectiveness of such changes? Cut and try techniques are too wasteful of time and energy, and rarely provide solutions to a given problem. The purpose of underground stress instrumentation is to provide answers to some of the above questions -- answers that cannot be obtained otherwise This does not mean that laboratory studies are not valuable -on the contrary. Laboratory and underground studies supplement one another. Rock mechanics had its conception with the study of stresses in homogeneous, isotropic, and elastic models subjected to various force systems. These analyses were valuable inasmuch as they pinpointed possible sources of trouble due to stress concentrations. If the results observed underground did not always agree with the experimental analysis, it was not an indictment of the latter. More probably, the discrepancy could be attributed to the lack of similitude between model and prototype. The more nearly one can simulate underground conditions in a model, the more apt one is to produce results which correlate well-with underground observations. It is impossible to completely simulate underground conditions because all of the significant design parameters have not been recognized and evaluated. What better way can one evaluate these parameters than by underground stress instrumentation?

Jan 1, 1963

By Dan Johnson

The discovery of rich alluvial diamond deposits on Namibia?s Skeleton Coast in 1908 began a period of intense exploration and mining off the coastal sand; and shallow surf zones. In the mid-60s a Texas entrepreneur, Sam Rollins took the search to the seafloor. The inhospitable conditions encountered made the early going difficult. After a slow start, the past 10 years have seen much progress in geologist?s understanding of the deposition mechanics and the use of sophisticated geo-physical and sampling techniques to aid in the discovery of economic deposits. Diamondfields, in a joint venture with BHP and Benguela Concessions, began an exploration program in 1994 for sea-bed diamonds off the Port of Luderitz in Namibia. This program has progressed to a mine development program with the potential of creating a 500,000 carat per year operation. The mining technologies being considered include state-of-the-art, remotely operated sea-bed crawlers and high volume dredges feeding to semi-mobile processing platforms. The company&apos;s objective is to use the best proven technology to create an environmentally responsible operation with the lowest fixed operating costs and the longest and safest weather operating window of any offshore operator working Africa&apos;s diamond coast.

Jan 1, 1998

By Robert B. Wickham

"American Barrick has always balanced its aggressive operating approach with a conservative financial strategy. In fact, what enables their mining team to pursue such aggressive plans with confidence is the conservative financial strategy adhered to by the company. These policies are built on a prudent mix of gold linked financings, equity and gold price hedging.This paper outlines these policies and focusses in particular on American Barrick&apos;s gold price hedging program.IntroductionThe company&apos;s balance sheet at the end of 1990 clearly shows the wisdom of its conservative policies. Total assets have grown to over US$1 billion; cash has grown to US$312 million and shareholders&apos; equity to US$645 million. All amounts included in this paper are quoted in U.S. dollars. Increased gold production and an effective gold price hedging program also combined to produce record income from operations, earnings and cash flow in 1990.The first half of 1991 is also indicative of the benefits of the company&apos;s conservative financial policies. Increasing production, together with its comprehensive gold hedging program, has generated increased earnings, even in a period of falling gold prices.All year-over-year numbers for the first six months are up. Gold production was 36% higher; earnings of $40.2 million $ 0.30 per share - were 46% higher than 1990.Barricks revenue continued to increase despite gold prices remaining unchanged during 1990. Barrick&apos;s hedging policy protects the company from falling gold prices on the basis that the upside looks after itself. Their hedging program - including various goldlinked fmancings - enabled Barrick to realize an average price of $437 per ounce of gold sold in 1990, compared with the Comex average gold price for the year of $384 per ounce."

Jan 1, 1991

By V Leus, J. Kallioinen

The large size of the modern flotation cells and the high product flow rate from them has increased the importance of optimal flotation of all the particle sizes and of process control. By treating all the subprocesses of flotation separately a new family of flotation cells and a new concept of optimizing the flotation of coarse and fine particles in separate units but in the same row of flotation cells has been developed. The paper discusses the possibility to enhance coarse particle flotation by varying the froth residence time. A function has been developed between the residence time of the froth, air rate and the froth removal rate of coarse apatite particles. The response of apatite flotation to different control variables has been studied and modelled. The results show that the BPL assay response depends not only on the control variable used but also on the feed assay to the cell. There exists an feed assay dependent region within which the froth assay can be controlled by using the froth residence time as the control variable. These regions can be used to tune a rougher-multistep cleaner circuit to optimal.

Jan 1, 1993

By R. Kossowsky

In the course of a study concerned with structural stability of precipitation hardening nickel base super -alloys after exposures to elevated temperatures, some interesting effects of hydrostatic pressure treatment on Rene were observed. The evidence presented below suggests that hydrostatic pressure treatment of the solution heat-treated alloy can affect the dispersion of the y&apos; (Ni3Al) phase upon subsequent precipitation heat treatment and long time aging. Rene 41 alloy has the following nominal weight percent composition: Al B C Co Cr Fe Mn Mo Ti Ni 1.4 0.006 0.7 11.3 19.2 1.0 0.05 9.4 3.3 balance The effect of successive pressure, precipitation heat treatment, and long time aging on the microstructure of this alloy was determined by subjecting a number of alloy buttons to five different thermopressure treatments. Pressure and precipitation heat-treatment parameters are listed in Table I. Fig. 1 shows y&apos; morphology* of specimens in groups I and 11. The treatment results in a fine dispersion with particle size on the order of 950 and 1350A, respectively, see Table I. Fig. 2 shows the morphology of y&apos; precipitate in

Jan 1, 1967

By Hargraves A. J

With increasing depth, stresses and stress phenomena are becoming more important considerations in Australian coal mining.A large number of compressive and tensile strength tests was made on coal and rock cubes cut from samples taken in various Australian collieries. In addition, an empirical impact strength test was carriedout on fragments of the same samples, to obtain a correlation with compressive strength.In one colliery, flat-jack measurements were taken to assess stresses in coal ribs and in the roof.INTRODUCTIONBy world standards, some of the New South Wales collieries are approaching depths of cover considered a maximum for bord and pillar the normal Australian coal mining method. Several South Coast collieries are winning coal at depths of about 1500 ft., and future operations are being planned at deeper cover. Some areas of these deep workings produce considerable quantities of seam gas.Phenomena associated with high stress and copious gas under pressure in the seam violent phenoma presenting a danger and a nuisance in mine working - have occasionally occurred, and the phenomena are being investigated as a whole (Hargraves, 1958), and separately as a gas problem (Bolt and Innes, 1959; Hargraves, 1962) and as a stress problem. This paper relates to the latter - to investigations into the strengths of coals and coal measure rocks, and into the stresses in and about coal seams...

Jan 1, 1962