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By Howard N. Eavenson

TWO months ago, just after the coal code hearing in Washington, one of our leading liberal weeklies printed a study of the coal industry made by an economist in the Administration, and on the outside cover bad it featured as "Coal-A Dying Industry." There are, of course, different opinions as to the accuracy of this characterization and I want to present some of the facts about the outlook for the bituminous industry for a short time ahead. In view of what has happened in the industry within the recent past it would be futile to attempt to make any prophecy about what is likely to occur in the future. We all know that a prophet is not without honor save in his own country, but it is likely that anyone undertaking this role about this industry would soon find himself in no man's land. One can, with some slight degree of safety perhaps, outline present conditions and tendencies and draw some inferences as to what the future may hold.

Jan 1, 1933

By G H. Clark

Batu Hijau is a porphyry copper-gold deposit located onSumbawa Island in the western Banda Arc of Indonesia. The deposit has been evaluated from 54 000 m of drilling in 105 diamond drill holes over a surface area of 1.2 km2 and to a depth of 1000 m below surface (412 m below sea level). A provisional plan is being evaluated to mine 642 million tonnes at an average grade of 0.61% Cu and 0.55 g/t Au (variable cut-off) from an open pit in the higher grade portion of the resource.   The deposit is associated with a calc-alkaline intrusive complex that was emplaced in a thick sequence of andesitic pyroclastic rocks. The oldest and most widespread intrusion is porphyritic to medium-grained, equigranular, quartz hornblende diorite. At Batu Hijau the western diorite contact zone was intruded by two phases of tonalite. The older tonalite is a stock increasing from 200 m diameter at surface to 500 m at sea level. It consists of quartz, plagioclase and hornblende phenocrysts set in a groundmass of similar composition. A younger tonalite intrudes the tonalite stock, quartz and plagioclase phenocrysts are more abundant and it has a finer groundmass than the older tonalite. Brecciation occurs near the older tonalite contacts but there are no breccia pipes or late-stage features such as pebbledykes or postmineralisation intrusive rocks.   Hydrothermal alteration of Old Tonalite and adjacent rocks is centred on the Old Tonalite and is zoned from a core of pervasive potassic alteration grading to an outer propylitic halo. At depth a propylitic assemblage is developed in the low grade core in the Old Tonalite. Phyllic alteration, late stage and mainly fracture controlled, overprints both potassic and inner propylytic zones. Intermediate argillic alteration overprinting is widespread, particularly on the eastern side of the hydrothermal system, where advanced argillic alteration overlies argillic alteration.   Ore grade mineralisation is cylindrical in shape, up to 800 m in diameter, and is centred on the Old Tonalite. A high grade shell (>0.75% Cu) forms an upward tapering cone in and around the Old Tonalite and reaches the surface in the centre of the deposit. Lower in the shell >l g/t Au and >2 g/t Ag accompany >1% Cu. Below 75 m above sea level mineralisation in the Old Tonalite rapidly decreases as a weakly mineralised core develops, but the limb continues to contain mineralisation to at least 412 m below sea level. Fracture and vein-controlled chalcopyrite and bornite are the dominant hypogene copper minerals and are the hosts for most of the gold mineralisation. Gold occurs free and in the lattice of the copper sulphides, and has been observed in quartz.   Weathering, especially where argillic alteration is developed, has produced a strongly leached cap, up to 147 m thick, below which is an irregular copper enriched supergene zone. Where leaching is not developed, such as over the centre of the deposit, an irregular oxide zone and a weakly developed supergene zone may be present.

Jan 1, 1995

By R. R. Falier, W. E. Rice

"PURPOSE OF REPORTThis paper presents the results of a series of tests made by the U. S. Bureau of Mines in cooperation with The Ohio State University Engineering Experiment Station as part of an investigation on the use of fuel in kilns.This report is preliminary and gives only enough of the test data to illustrate results and show the reasons for the successes and failures of the method of firing investigated; fuller details will be included in the final report.PERSONNEL FOR TESTSThe investigation is conducted under supervision of P. Nicholls, supervising fuel engineer, of the United States Bureau of Mines, and G. A. Bole, research professor, of The Ohio State University. These tests were made under direction of W. E. Rice, associate fuel engineer, assisted by R. R. Faller, assistant fuel engineer, of the United States Bureau of Mines; H. C. Harrison, senior research engineer (until October 1, 1930), C. R. Austin, senior research engineer (since October 1, 1930), and H. K. Van Sohoick, junior research engineer, of The Ohio State University. M. J. Rice, field engineer, represented the manufacturer of the stoker.PURPOSE OF INVESTIGATIONThe general aim of the investigation is to develop more economical methods of using fuel in kilns and to improve the over—all efficiency of the process of firing by methods that will produce ware of better quality. One phase of this investigation is the burning of coal on an automatic stoker to gain the advantages of control, constant rate of application of heat, and ability to burn cheaper coal than can be used in the hand—fired furnaces of kilns. It a stoker in to be used it is desirable that the coot of the installation should be low, the control of operation simple, and the distribution of heat in the kiln as good or better than with hand firing. These desiderata were sought in the stoker and furnaces that were used for the tests described herein. The tests were made to determine whether it is feasible to fire a large kiln with a single stoker, whether the use of a single furnace simplifies control, and whether the admission of all the hot gam at the center of the kiln will give symmetrical distribution of heat."

Aug 1, 1931

By T. J. Yeomans

"The Kidd Creek metallurgical site is situated twenty-six kilometres east of Timmins, Ontario. The site consists of a 4.5 niillion tonne per year concentrator, a 127,000 tonne per year electrolytic zinc plant and a 79,000 tonne per year copper smelter/refinery complex.The concentrator commenced operations in 1966 and was expanded to its present capacity in 1978. The zinc plant commenced operations in 1972, and the copper smelter/refinery in 1983.The concentrator tailings, and both liquid and solid waste products from the other plants are disposed of within a 1215 hectare tailings disposal area. Here, a method known as centraljzecl thickened discharge is used to form a stable cone-shaped hill. A low permanent perimeter dyke structure encloses the cone and directs cone run-off and thickener overflow to a treatment pond. After treatment with lime slurry, this neutralized effluent is recycled to the metsite and also discharged into the Porcupine River system.The tailings system has been in operation in its present form since 1972, upon completion of dykes and a 110 metre thickener unit. Underflow densities were continuously increased until thickener overloading became a serious problem. This necessitated the construction of a second 110 metre thickener, which was completed in 1983. Target densities have been achieved without difficulty since then.This paper discusses the operation of the tailings system, reviews past performance, and outlines future operations."

Jan 1, 1986

By M P. Cipold, J F. Bachmann, C C. Bachmann, J Ha, H B. Wurst

In washability, the objective is to establish the set of maximum possible separation performance criteria for a given mineral feed. The method of choice for this has been the conventional sink–?float analysis. Using traditional sink–float method it is not possible to sample and automatically measure. This fact, as well as time, cost and safety aspects, as well as required and manageable sample size of the sink–float method have prompted the search for a new approach for establishing separation performance criteria. This is especially important as performance levels of separator plants can be maximised if reliable information based on an analysis of washability in conjunction with particle size distribution, elemental constituency becomes available in time. The new method to establish washability and associated performance information utilises at least two measurement technologies concurrently: single energy X-ray transmission and image processing. For porous or very inhomogeneous materials the results can be refined further by using dual energy X-ray transmission and image processing.If used as a standard laboratory device the continuous build-up of the washability curve allows to evaluate the statistical significance of the sample size during measurement.The measuring method can even be improved if it is combined with an automatic sampling system that feeds a continuous and representative particle stream to the analyser. Then the value of the collected data increases considerably since the washability data are additionally available in time to be considered in the control of the process plant. The washability curve can be derived and is continuously updated based on the particles measured during the past time interval. Older curves and results are stored in a database and can be retrieved for later reference. This technology now enables automated sampling and integrated automated measurement, which was previously not possible.This incorporation of an automated washability monitor at a representative sample gives near real-time data that would impinge positively on the profitability of the plant operation. The method was extensively tested using a range of samples with different densities, varying from 1 g/cm3 (coal) to 5 g/cm3 (iron ore).CITATION:Bachmann, C C, Bachmann, J F, Cipold, M P, Wurst, H B and Ha, J, 2017. Inline analysis of washability parameters for process control, in Proceedings Eighth World Conference on Sampling and Blending , pp 213–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By M. C. Azar, W. B. Mason, G. L. Anderson

Eminent domain overview Eminent domain is the power of the Government or a municipality to take property for public use without the consent or acceptance of the owner. Typically, the agency taking the prop¬erty will make an offer, hoping the owner will immediately accept and allow work to begin. If a mutual resolution regard¬ing its value cannot be reached, how¬ever, the municipality will institute a condemnation action in court seeking possion of the property. This is when the problems begin. The power of the Government to take the subject property is limited by Federal and state constitu¬tional requirements to pay "just com¬pensation" for the property. The exact nature of an owner's prop¬erty has been the subject of much debate and discussion. It is generally under¬stood, though, that property is consid¬ered to be "every kind of right or inter¬est, capable of being enjoyed and recog¬nized as such, upon which it is practi¬cable to place a money value" (US vs. 53 114 Acres of Land). A taking, for condemnation purposes, is considered to occur whenever there is a substantial interference with the free use and enjoyment of the property. Rarely is the necessity for the taking ever challenged and more rarely is the taking ever successfully challenged. When a taking occurs, it is not only the fee owner who is entitled to compen¬sation. Every person holding an interest in the subject property will be recog¬nized. Thus, all persons who at the time of taking have a compensable interest in the property will be made parties to the case (Swanson vs. US). Minerals, like all other interests in land, are recognized as property rights, giving the owner the power to dispose of them as he or she sees fit. Thus, the only remaining considera¬tion is only "just compensation." Ex¬actly what "just compensation" is has been difficult to define. Generally, it is that amount of money that will "put the person in as good a position as the per¬son would have been in had the taking not occurred." The owner must not be forced to sacrifice or suffer by receiving less than full and fair value for the prop¬erty. Every element that effects the value of the land and that would influence a purchaser must be evaluated. Courts have employed a variety of techniques to determine just compensa¬tion but have generally relied on market value as the standard for measuring compensation to the owner. The deter¬mination of market value is based on sales, income, costs, and use. These factors have been employed in various ways but can be summed up as: -The highest estimated monetary price the property will bring if exposed for sale in the open market with a reason¬able amount of time allowed to find a purchaser who is buying with knowl¬edge of all the uses and purposes to which it is adapted and for which it is capable of being used. • The amount the property would bring if it were offered for sale by one who desired, but was not obliged, to sell, and was bought by one who was willing, but not obliged to buy. • What the property would bring in the hands of a prudent seller, at liberty to fix the time and conditions of sale. • What the property would sell for in negotiations resulting in sale between an owner willing, but not obliged to sell, and a buyer willing, but not obliged to buy. • What the property would be rea¬sonably worth on the market for a cash price, allowing a reasonable time to affect a sale. (Michigan Standard Jury Instructions). Special consideration regarding mar¬ket value is given when the taking is only partial, rather than complete. An example of this partial taking is when a state highway cuts across the northern half of a parcel of property, leaving the rest behind for the owner. A variety of problems can be immediately seen. In a partial taking, the owner is permitted to recover not only for the property taken, but also for any loss in the value of the remaining property. The measure of compensation for partial taking purposes is generally the difference between the market value of the entire parcel before the taking, and the market value of what is left of the parcel after the taking (Michigan Stan¬dard Jury Instructions). Determining the partial taking value for mineral bear¬ing lands is the difficult issue.

Jan 1, 1989

By Jon C. Volkwein

The U.S. Bureau of Mines has developed a method to measure methane and other gases during the auger mining of coal. An intrinsically safe commercial gas detector with a built-in data logger was mounted in the center of the hollow conveying auger. A sampling head through the wall of the auger conducted a gas sample to the detector. Results showed that gas levels can be monitored on a continuous basis during the auger mining of coal and the data retrieved upon completion of the hole.

Jan 1, 1994

By Marius R. Campbell

VARIOUS classes of coals are recognized in this country at the present time. These classes depend largely upon physical characteristics rather than upon chemical composition, and consequently they cannot be accurately defined. The divisions into anthracite, semi-anthracite and semi-bituminous are fairly satisfactory; but the term bituminous embraces so large a variety of coal that it is of little value, and the term lignite is so loosely applied that it has little or no place in a scientific classification. At present there is no way of accurately defining the vari¬ous classes of coal, because no adequate scheme of classification, which applies to lignites as well as bituminous coal and anthracite bas been proposed. The object of this paper is to present such a scheme, which is based upon data obtained dur¬ing the past year by Prof. N. W. Lord,1 in charge of the chemical laboratory of the United States Geological Survey coal-testing plant at the Louisiana Purchase Exposition, St. Louis. All the classifications of coals proposed prior to 1877 were based either on physical characteristics or on proximate analyses, including all of the impurities. These schemes were illogical and highly unsatisfactory, for the physical properties of a coal give little indication of its true composition; and impurities, such as ash and sulphur, are largely the results of acci-

Sep 1, 1905

By D. K. Ingram, P. Jurovcik

The National Institute for Occupational Safety and Health (NIOSH) identified hearing loss as the most common job-related disease in the United States in its 1996 National Occupational Research Agenda. Previous studies by NIOSH have shown that operators of surface drill rigs without cabs are commonly exposed to A-weighted sound levels exceeding 90 dB. During hammer-drilling, A-weighted sound levels exceeding 100 dB were recorded at the operator station. NIOSH collaborated with a local drilling company to design and install a partial cab between the operator and the drill steel in an effort to reduce the sound level at the operator station. Sound level measurements in the field show the partial cab reduces the A-weighted sound level by 5 to 9 dB at the operator’s left ear and 2 to 5 dB at the operator’s right ear while hammer-drilling. This paper briefly discusses the preliminary design of a cab and the testing of materials for construction of the prototype. An explanation of the ideas behind the prototype design and fabrication are covered. Finally, the field test method and results are discussed in detail.1

By T. Grewar

"South Africa is a water-scarce country, rated as one of the 30 driest countries in the world. Worryingly, government expects water demand to outstrip supply as early as 2025. The South African government believes that substantial volumes of water can be made available through the reuse of treated mining-impacted water. Currently, however, large volumes of treated mining-impacted water are produced, often with no end use in mind other than discharge or disposal, when these treated effluents may have further uses in applications which are currently and unnecessarily using high-quality water. Treating the wastewaters to levels that meet ’fitness-for-use’ guidelines for alternative applications such as agriculture, sanitation, or industrial processes will reduce the treatment cost burden compared to potable water production. The primary conclusion of this review is that the most suitable option for re-using treated mine-impacted water is in agriculture, for irrigation of crops (food, forage, or energy crops), which currently and unnecessarily makes use of the majority of South Africa’s high-quality resources or potable water. Other findings include the realization that although guidelines and legislation for water re-use in South Africa exist and are readily available, they tend to be contradictory and confusing in many cases. It is imperative that these ambiguities and incongruities in the available guidelines and legislation for water re-use be clarified and updated swiftly IntroductionSouth Africa is a water-scarce country and is currently rated as one of the 30 driest countries in the world, with an average rainfall of 490 mm/a, approximately half of the global average. As an indicator of the degree of regional variability in South Africa’s water supply, it has been shown that 70% of all runoff is from approximately 20% of the land area. Regardless of the water scarcity faced in South Africa, our water conservation track record is poor, with an average consumption of 280 L/d per person, almost 60% more than the global average of 175 L/d per person. Around 40% of this allocation is utilized in watering lawns and gardens (Zhuwakinyu, 2017).The South African government predicts water demand to outstrip supply as early as 2025. On an international scale, the situation appears just as dire, with the United Nations High Level Panel on Water (HLPW) expecting a 40% water shortfall by 2030, which may affect up to 1.8 billion people based on current water demand trajectories (Zhuwakinyu, 2017)."

Mar 1, 2019

By G Veillette, B Parker, S Hart

This paper provides a history of the challenges that were experienced while treating both the clayey oxide gold ores and the supergene copper-gold ores at the Boddington Gold Mine during the period 1989 to 2001. However the bigger challenge was to find a process flow sheet that would allow the economic treatment of the large low-grade competent gold-copper resource that underlies the oxide and supergene gold resource. Metallurgical test work and engineering studies on this resource started in the mid 1990s and culminated in the approval in 2006 of the 35 Mtpa Boddington Expansion Project to treat this material. The process flow sheet provides the basis of an energy efficient comminution circuit that includes high pressure grinding rolls and a treatment circuit with gravity separation, flash and conventional flotation to produce a precious metal low-grade copper concentrate followed by cyanide leaching of the rougher-scavenger and cleaner tailings streams. The treatment circuit allows maximum removal of copper minerals prior to cyanide leaching and so provides an environmentally responsible tailings disposal circuit.

Jan 1, 2007

By S. Ramachandran, N. J. Grant, T. B. King

MANY investigations of the rate of the sulfur transfer reaction between carbon-saturated iron and blast furnace type slags have been made." It is evident that the reaction is complex, the rate being affected by the presence of elements dissolved in the metal that are readily oxidized and therefore capable of existing in the slag phase. Thus Goldman, Derge, and Philbrook- have shown that carbon, silicon, manganese, and aluminum, in order of increasing effectiveness, accelerate sulfur transfer from iron containing these elements to blast furnace type slags. Quantitative information is still, however, not available on the relation between what have been termed side reactions, such as silicon transfer and CO evolution, and the sulfur transfer reaction itself. In other words, the stoichiometry of the reaction has not been investigated. In the present investigation, the transfer of all reacting elements and the evolution of CO have been measured simultaneously in order to establish the mechanism of the reaction which occurs in practice. Information of this nature cannot be deduced from equilibrium studies. It should be pointed out that in kinetic studies of this type quantitative conclusions are applicable only to the system studied. This restriction should be borne in mind when attempts are made to compare results from different investigations. Apparatus The apparatus used enables slag and metal samples to be taken at frequent intervals and also provides a continuous record of the amount of gas evolved. A sketch of the apparatus is given in Fig. 1. It may be considered in three sections: 1) furnace section, 2) blank volume section, and 3) pressure measuring section. The furnace section is shown in detail in Fig. 2. It consists of two graphite crucibles, C and D, super-

Jan 1, 1957

The district specially referred to in this paper comprises the very gently sloping country extending from the western shores of Port Phillip from the mouth of the Yarra to Footscray along the Bacchus Marsh railway to near that town thence in a southerly direction to the Little River, and along that river to the coast, 1 as may be seen on the accompanying map. Almost the whole of this area is covered by volcanic rocks, consisting of pumerous sheets of basalt, which have been poured out of various volcanic hills in the districts, such as Mts. Atkinson and Cotteril, near Melton; Mt. Maryand Bald Hill, 12 and 16 miles respectively N.W. of Werribee; and vents in different parts of the parishes of Tarneit, Mouyong, Mooradoranook, Pyweitjorrk, and Derrimut. These volcanoes were in an active state of eruption during a late period of the earth's historyprobably the late Pliocenll, or still younger Pleistocene.Occupying a narrow strip of country, for most of the distance along the coast from Williamstown to past the mouth of the Little River, there occur deposits of still younger age, belonging to the Recent period. These lie on the basalt, and extend for distances varying from a few chains to more than a mile back from the beach. They comprise superficial deposits of blown sand, and raised beaches, composed of marine sands...

Jan 1, 1902

By A. Dale Wunderlich

Since Sept. 11, 2001, the author has been asked by several mining companies and mining publications to share some of his insights on how the terrorist attacks on the World Trade Center (WTC) and Pentagon might affect the mining industry globally. Until now, the author has been reluctant to express his thoughts in a publication that could possibly fall into the hands of terrorists and give them some ideas that they may not have been previously considering. However, the author discussed the contents of this article with several friends and acquaintances in the international intelligence community. They said that nothing commented on here is new to the terrorists. Potential terrorist targets Sources within the worldwide intelligence gathering community have told the author that current intelligence data indicates that it is likely that the Islamic fundamentalist groups responsible for the attacks on Sept. 11, 2001will likely be directing their effort at foreign business entities. Any overseas or any domestic businesses of highly visible companies that are part of the anti-terrorism alliance should consider themselves a potential target.

Jan 1, 2002

By Brain E. Gombos

The Allen Park Sanitary Sewer Overflow (SSO) Tunnel and relief sewer project, located in the city of Allen Park, MI, is a long-term corrective action designed to bring Sanitary District One?s sanitary system into compliance with its 2005 consent order and service contract with the Detroit Water and Sewerage Department (DWSD). The $20 million project is intended to reduce Allen Park?s wet weather discharges to DWSD, reduce bypass pumping to the Ecorse Creek and limit the future risk of basement flooding by providing storage during wet weather events and eliminating hydraulic bottlenecks in the sanitary sewer system.

Jan 1, 2013

By G Milligan

This paper describes how water is being planned, managed and used in Queensland as both a precious natural resource, vital for healthy ecosystems, and as a valuable tradeable commodity, necessary to secure economic prosperity. Queensland has been progressively implementing a planned package of water industry improvements agreed by the Council of Australia Governments in 1994. The Water Act 2000 provides the legislative basis for implementing the COAG water reform framework in Queensland and sets out statutory water planning processes. A Water Resource Plan (WRP) is a strategic document that specifies water sharing and environmental flow outcomes across a whole catchment over a period of up to ten years. A Resource Operations Plan (ROP) sets out the details of implementing a WRP, including environmental flow rules, establishment of tradeable water allocations that are separate from land, rules for water trading, rules for operating water infrastructure, arrangements for the release of any unallocated water identified in the WRP, and requirements for monitoring and reporting. Water Resource Planning and Resource Operations Planning are progressing in priority catchments and aquifers across the State. Ways to obtain a water entitlement now depend on whether a WRP and/or a ROP exist in a particular catchment. Water trading provides for the buying and selling of water entitlements on a permanent basis where permitted under a ROP. Details of tradeable water allocations are securely registered on the Water Allocations Register, which is similar to a land titles register. Leasing and temporary transfers of water entitlements are also possible. Water brokers are emerging to facilitate water trading which aims to improve water use efficiency and move water to higher value uses. Queensland is leading the way in the implementation of the COAG water reform framework and the pursuit of sustainable water resource management. The StateÆs progress in this regard is increasing certainty for water users, while ensuring that considerations of equity amongst existing and future users and amongst various uses, as well as considerations of ecological sustainability and the wider community, are all taken into account. The mining sector stands to benefit substantially from these new approaches to planning, managing and using this precious resource.

Jan 1, 2003

By J. R. Parga

In mineral processing, poor froth-flotation performance translates into both an enormous loss of revenue and an unnecessary waste of the ore reserve. In this context, Bacís Mining Company developed a versatile new, high-performance flotation-cell design that can be incorporated into various flotation circuits. The main feature of this circular cell is that it is comprised of two separate sections, namely, a flotation cell that uses wash water to minimize the entrainment of fine gangue particles into the froth product and an external bubble generator that produces small bubbles of relatively uniform size at a specified aeration-rate. The air/water mixture is blended with the pulp by gentle agitation, so as to enhance particle-bubble aggregate-stability. Comparative metallurgical performance with conventional flotation cells show that the power requirements and operating costs for precious metal flotation are three times lower, while the concentrate grade is 7% higher and the recoveries of precious metals are 5% higher.

Jan 1, 2009

By Daniel H. Israel

Indian tribes own a substantial portion of the West's minerals. More importantly, Indian reservations contain coal, oil and gas, uranium, and oil shale reserves in unusually large and unencumbered blocks. Many tribes are now prepared to intensify development of their large reserves knowing that they can offer energy partners the unique opportunity to develop major energy facilities free of overlapping local, state, and federal permitting authorities. The tribes, therefore, can offer mineral developers both substantial reserves and an unusual degree of freedom from a multiplicity of government regulation. In the past, Indians and energy companies enjoyed only partial success as business partners. Indian tribes lacked the resources and know-how to act as equal partners with large oil and gas and mining operators. The tribes relied on the Bureau of Indian Affairs (BIA) to initiate and execute reservation energy projects, and as a result the tribes never developed adequate tribal structures and the expertise to responsibly manage their energy resources. At the same time industry made little effort to understand and learn the laws, customs, and institutions existing on Indian reservations. To the contrary, industry found it easier to bypass the tribes and deal with BIA officials. But the situation has changed. In 1975 the tribes organized an effective coalition, the Council of Energy Resources Tribes (CERT), which recently acquired substantial federal assistance to bring the tribes a level of technical and business expertise that begins to equal that of industry. Because the tribes have changed the rules of the game, industry must now change and learn to work directly with tribal governments. A working knowledge of Indian law, practices, customs, and policies must be acquired by energy companies before beginning negotiations with tribal governments for development of reservation energy resources.

Jan 6, 1980

By Ali Hasham

Reduction rates of FeO in CaO-SiO2-Al2O3 slags by Fe-C melts have been investigated experimentally at 1723 K. The rates were estimated using experimentally determined CO(g) evolution rates. Flash X-ray images were employed to visualize the behavior of the melt-slag interface during the reactions. The influence of melt interface was examined by conducting two types of experiments - (i) dropping one (or several) Fe-C droplet(s) weighing 2 g into the molten slag bath, and (ii) dropping a small amount (10-30 g) of slag onto a Fe-C melt weighing 400 g. The rates from both types of experiments were compared and analyzed to determine the rate limiting steps. It was established that neither the carbon transport in the Fe-C melt, nor the transport of gas species in the gas film adjacent to Fe-C melt was responsible in limiting the reaction rate. It is possible that the slag phase mass transport may be controlling the initial reduction rate in the droplet experiments. However, a, different mechanism was responsible in limiting the reduction reaction when the overall %C in the droplets fell to about 2-3.

Jan 1, 1992

By William R. Yernberg

In October 1999, Liebherr-America, Liebherr Construction and Liebherr Mining Equipment held anopen house at its Newport News, VA, plant. The open house was held to celebrate the company’s50th anniversary and to demonstrate the new TI 272mining truck. Attending the open house members of the media, vendors and company representatives from all over the world. In his introductory comments, company president Peter Eller announced Liebherr’s dedication to expanding its presence in North America. Liebherr now has 30 dealers across the United States. As part of the open house, a brief history of Liebherr was presented, beginning with its creation in1949. Liebherr engineering and sales representatives were available to answer questions.

Jan 1, 2000