Search Documents

By E. You

Kennecott Utah Copper Refinery and Outokumpu Technology have developed a wireless Electrolytic Cell Monitor (CellSensor) system to monitor cell voltage and temperature. The system is based on a robust self-organizing and self-healing wireless network with a very reliable redundant structure. The microprocessor controlled CellSensor device operates off a small amount of energy harvested from the cell bus and requires no external power source. The radio works in the 2.4 GHz international ISM band using robust Spread Spectrum technology. The CellSensor does not require end user calibration of either the voltage or temperature sensors and accuracy is superior to previous systems. The on-board computation power allows digital filtering of the cell voltage signal which results in very high quality data. The system requires much less maintenance than conventional hardwired systems and is intrinsically safer since no high voltage isolation is required. The advanced diagnostic functions allow the device to determine if the bus tap contact is degrading. The CellSensor can also be used for monitoring electrowinning (EW) cells for a variety of metals. CellSensor have been tested for over two years at the Kennecott Utah Copper and Boliden Harjavalta Pori refineries. The CellSensor system is now commercially available through Outokumpu Technology.

Jan 1, 2007

By Fathi Habashi

"Crushing and grinding of ores and their beneficiation by washing away gangue minerals has been practiced since ancient times. Primitive crushing was done by hand pounding the ore with a hard stone then by using metallic hammers. The mortar and pestle was mechanized using a lever and when the size of operations increased in the middle ages, the stamp mill was introduced. The grindstone played an important role in grinding of ores. Panning for gold and hand sorting of minerals were two old methods of separation, now gave way to modern techniques. Flotation started in the middle of the nineteenth century by using oils to collect the mineral particles and float them on the surface of the aqueous slurry. It was only in the 1920s when it was discovered that organic compounds were affective floating agents. Textbooks written by distinguished engineers such as Rittinger, Rickard, Pryor, Taggart, Richards, Gaudin, and others contributed to the recognition of this field as a new discipline to be taught in Universities. INTRODUCTIONThe ancient Egyptians knew already that it would be easier to melt an earth rich in gold particles than another which is poor. As a result all efforts were made to enrich the gold by washing away the light gangue minerals (Figure 1). Another ancient method for enriching gold particles from a river stream was by means of fleece, hence the Greek myth of the “golden fleece”. The present day Georgia was known in ancient times as Colchis and was a center for gold working. It was known to the ancient Greek as the land of Golden Fleece. The use of special cloth to catch gold particles was also described by Agricola in his 1555 book De Re Metallica (Figure 2)."

Jan 1, 2009

By Andrew Bamber

Between the early 20th Century and the present, the production of mined copper ore has increased from tens of millions of tonnes per annum to several billion tonnes per annum, an unprecedented increase. Contemporaneously, the average grade of mined copper ore has declined from over 2% to approximately 0.5%. Again, in parallel, the price of copper has increased dramatically to reflect the increasing cost of extracting and beneficiating such large amounts of low-grade ore. Within the period the copper price however exhibited several periods of intense volatility, driven by interrelationships between demand and supply, themselves strongly driven by periodic industry developments in the fields of exploration, ore extraction, mineral processing and extractive metallurgy. It is notable that these periods of intense innovation exhibit a strong correlation to preceding periods of price, demand or production volatility. This paper examines key trends in each theme between 1900 and 2018 and draws strong conclusions as to the interrelationship between them. INTRODUCTION The production of copper metal has increased from around half a million tonnes per annum to over fifteen million tonnes per annum over the course of the 20th Century. Contemporaneously, the average grade of copper ore mined has declined from over 2% to approximately 0.5% copper by weight. As a result, the volume of Run-of-Mine (ROM) copper ore required has increased from around ten million tonnes per annum to over a five billion tonnes per annum over the period, an unprecedented increase. The adage is that demand drives supply, that prices rise in times of high demand and/or short supply, and that prices fall when supply catches up with demand. The market sellers in biblical times knew this well; mediaeval market sellers equally. Dutch tulip sellers in the 1600’s experienced both in extremis — much to their dismay — and the great industrialists and early capitalists of the industrial revolution knew this also. Mining recently went through a cycle where investors and producers both believed that the “old” rules did not apply any more and that the industry was in a “supercycle” where prices would continue to rise on the back of increasing demand. However, as the GFC of 2008–2011 showed, this was not to be. Another adage says that we constantly innovate to lower costs of production. Is this true? Do we only innovate to lower cost? Has the true cost of producing copper actually gone down over the century? Or are there other balancing forces at play? Herb Kellogg, in his Centenary address to the American Institute of Mining Engineers (now SME), categorized two types of innovation: ‘Bigger and Better’, and ‘New Process’ (Kellogg, 1970). ‘Bigger and Better’ allows increased production at presumably lower cost; ‘New Process’ supports the same result at presumably the same scale, but at significantly enhanced efficiencies and (therefore) lower cost. It is suggested that both types of innovation are constantly and interchangeably required to achieve the kind of scale-up, at achievable operating and capital cost that the industry has achieved over the period. What can be shown, over this last Century and a bit, is that supply and demand are indeed inextricably linked, price and demand are linked, but so are price and cost of production. And the innovation required to sustain that weaves in between them all, cost-effectively increasing production capacity or lowering the cost of production at the same throughput, and sometimes both.

Jan 1, 2019

By Zachary Mayer

Agenda ? Kidd Mine ? Background ? Problem & Opportunity ? Challenges associated to depth - Production Rates - Productive Work Time - Operational Delays - Transfer Levels - Mucking Time - Impact on Hoist ? LHD Automation ? Sandvik AutoMine Lite ? Expected Benefits Kidd Mine - Background ? Located in Northern Ontario, Canada ? Underground base metal mine operating since 1966 ? Total 148 Mt mined (2.31% Cu, 6.08% Zn, 75 gpt Ag) ? 2.35 Mt/Y from stopes as deep as 9500 ft (2.9km) below surface ? Mining method: blasthole open stoping ? Mine/Mill: 1263 employees and contractors ? 2012 National John T. Ryan Safety Award

Aug 1, 2013

By J. R. Perumareddi, V. S. Sastri, M. Elboujdaini

It is well known that high strength steels used in aerospace industry, are generally susceptible to hydrogen embrittlement during surface treatment such as electroplating with zinc on cadmium. Hydrogen embrittlement reduces ductility and results in brittle fracture rather than failure by plastic deformation. Hydrogen embrittlement of high strength steels is mitigated by surface treatment such as plating with other metals. Data on the hydrogen contents of steels before and after surface treatment by hot extraction-thermal conductivity, secondary ion mass spectrometry (SIMS) and UV-visible spectroscopy along with the mechanism are presented.

Jan 1, 2006

By V. C. Wittchen, T. R. Yu, J. E. Croxall

"The consolidated rockfill at Kidd Creek Mines is a weakly cemented, minus 15 cm aggregate which posed problems for conventional drill/blast drifting methods. Consequently, lateral access to mineable ore adjacent to backfilled areas was gained by drifting around the fill in shattered rock.In mid-1987, Kidd Creek Mines began to investigate means of mechanically excavating drifts in backfill . The results of this investigation led to a trial program using a Dosco MK-2A Roadheader to excavate the required drifts in backfill.The roadheader was tested at Kidd Creek Mines from July to November 1988, in 28-735 X /C to be used as the top access for drilling and blasting 32-74/ ST. During this period, the roadheader excavated 54 m of a 4.3 m by 3. 7 m arched drift in backfill. Cutting rates over the period averaged 0.8 m/cutting hour as projected with a daily high of 2.0 m/cutting hour.Wood-lagged 2-piece steel arches on 1.2 m centres were chosen as ground support for the trial. Shotcrete will be tested in a roadheader drive for its potential to improve productivity by replacing the steel arches.The trial program included evaluations of point-attack picks, two sizes of cutter motor, 20 MPa (3000 psi) water-assisted cutting, cuttings-removal systems, and environmental control devices."

Jan 1, 1990

By A. R. Barnes, R. Pandher, T. Shannon, P. Gover

Following the closure of the Glencore Zinc Brunswick mine, the Glencore Brunswick Smelter has transitioned to treating external feeds, and currently treats a number of secondary Pb-Zn concentrates. Processing these concentrates has in some cases been challenging due to the diverse mineralogy of the feeds. Certain feeds are difficult to ignite or show inadequate sulphur removal during oxidation on the sinter strand, while in other cases, combinations of feeds produce a sinter with unsuitable properties for further handling. This paper discusses two methods developed in collaboration with XPS Consulting & Testwork Services to characterize these feeds prior to processing them and to identify which ones are most likely to pose challenges during processing.

Jan 1, 2014

By F. G. Smith

Abstract Laboratory methods are now in use whereby the temperature and pressure during the crystallization of hydrothermal minerals can be determined. The techniques include the use of the decrepitation method of studying liquid inclusions, and electrical measurements of pyrite. The determinations are sufficiently accurate that the data can be used in solving a variety of ore deposition problems. Within the last year, several new laboratory techniques have been developed in the Geochemical Laboratory of the Department of Geological Sciences, University of Toronto. The results of several tests of ore by these methods have proved to be useful in treating some problems which previously were considered unsolvable. It is now possible to determine the temperature of deposition of most of the minerals in a hydrothermal ore deposit, also the depth below the surface during deposition. Measurements can also be made of the reopening history of a complex ore. The temperature-pressure determinations depend upon the fact that minerals deposited from a hydrothermal solution always trap a small amount of the solution at the time of crystallization. The solution, being predominantly composed of water, has a density which depends upon the temperature and the pressure prevailing during crystallization. After ore deposition is complete, erosion and isostatic uplift finally exhumes the vein. During this slow fall in temperature and pressure, the solution contracts and a gas bubble appears. If the trapped solution in the mineral is examined, the gas-liquid ratio records the density of the solution at the time the mineral was deposited (except for a slight change in the volume of the mineral). The thermal expansion and compressibility of water and water solutions are known to a sufficient degree that, if the gas /liquid ratio can be determined, the temperature-pressure relations during deposition can be calculated.

Jan 1, 1949

By J. A. López-Molina, S. García, V. Castellanos-Pedroza

"Groundwater inflow into underground constructions may cause hazardous working conditions and environmental problems. It is essential to localize and characterize potential flow paths and to estimate the amount of water leakages, so that appropriate sealing works can be performed. Estimating the amount of water ingress is a multi-phase process starting from qualitative and quantitative examination of rock mass. Due to association of uncertainty, vagueness and incompleteness with the monitored data set, particularly resulted from the in situ tests, accounting relevant approaches such Fuzzy Logic and Recurrent Neural Networks, are proposed in this research for learning acquisition, extraction of rules and prediction of behaviors. The computational set of artificial tools permits using the complex information entities or information granules (rock types, geologic structures, hydro-fracture potential) for data abstraction and derivation of knowledge from records (numerical or linguistic format). This is more a theoretical perspective than a set of methods or principles. As a theoretical perspective, this proposal encourages an approach to data that recognizes and exploits the information present in indexes at various levels of resolution or scales. In this sense, it encompasses the methods which provide flexibility and adaptability in the resolution at which knowledge or information is extracted and represented. The product of merging these tools is a 3D artificial-mapping of rock classification (Qi-system), geological conditions and Lugeon units that permits, as far as possible, to understand more and better the flow behavior."

Jan 1, 2015

By N. Thompson

The Right Hon. Viscount Long, late Secretary of State for the Colonies, in his inaugural address to the Empire Mining and Metallurgical Congress in London last June said: "I am more and more? convinced by every day experience that the development and strengthening of the Empire must depend upon individual effort and action, and that it is useless to look to Governments for assistance." I am inclined to agree with Viscount Long, to this extent, that the initiative must come from individual effort, but Government assistance is necessary to put the results of that effort and action into effect. It is perhaps fitting at a gathering of this kind to remind ourselves of the part the mining industry has played, not only in the development of the British Empire but in the world at large, in the promotion of modern civilization. We do know that all human progress has been coincident with the early discoveries in the recovery and treatment of metals and, as the centuries have passed, the human race has become more and more dependent on these sciences as factors of all progress, and no nation has ever become powerful and prosperous that has lacked adequate mineral supplies, or having these, has allowed them to be exploited by other nations.

Jan 1, 1925

By G. M. Ritcey, K. E. Haque

"Laboratory-scale sulphuric acid leach tests were conducted on Elliot Lake and Rabbit Lake ores in the presence of various oxidants, namely: Fe2(SO4)3, CI2, H2O2, NaClO3, MnO2, H2SO5, HNO3, Oxon e, K2Cr2O7, KMnO4, O3 and O2. Uranium extraction is significantly accelerated when an oxidant is present in the leach slurry. Uranium extraction of 96-99% can be achieved by maintaining the oxidation potential of the leach slurry in the range of400 to 500 m V (S.H.E.). A rough cost comparison of all the oxidant s indicates that the use of Fe2(SO4)3, 02, O3, C12, HNO3 or MnO2 is far less expensive than NaClO3 and the uranium extraction rates are similar to or better than with NaCIO3. For uranium extraction, it is concluded that gaseous oxygen (i.e., air or oxygen) would be the most effective and economical oxidant for the 24- to 36-hour leach of Elliot Lake ore; whereas for the 8- to I2-hour leach of Rabbit Lake ore, a strong chemical oxidant (e.g. NaCIO3, H202, 03, K2Cr2O7, H2SO5 or HNO3) would be a logical choice.IntroductionThe common practice for the treatment of uranium o res is leaching with sulphuric acid or with a carbonate-bicarbonate mixture. Generally, the latter process is ad opted when an excess (> 18%) of acid-consuming components (e.g., carbonate) is present in the ore. Irrespective of the nature of the leachant, the addition of an oxidant to the leach mixture is necessary to obtain a high uranium extraction.The maximum extraction of uranium can only take place when all the uranium is in the highest oxidation state (i.e.,U +6-uranic ion) . Because a certain percentage of uranium present in the ore is invariably in the lower oxidation state (i.e.,U+4-uranous ion) , the addition of an oxidant to the leach slurry is necessary to oxidize uranous ion to the uranic state."

Jan 1, 1982

By A. R. Hekmat

Hypereutectic Al-Si alloys are used in applications that require high resistance to wear and corrosion, hardness and low coefficient of thermal expansion, To maximize the properties of these alloys, semi-solid processing can be utilized to modify the solidification structure of the primary silicon crystals as well as to reduce microsegregation and porosity, The transformation and spheroidization of primary Si crystals by shearing in the semi-solid state are not fully understood as they precipitate in the presence of other alloy phases, The objective of the present work is the determination the rheological characteristics of A390 (Al-17%Si-4,5%Cu-0.5%Mg) alloy using a Couette type (Haake RV12) viscometer and examining the microstructural evolution during continuous cooling and isothermal shear rate experiments, The effect of shear rate, solid fraction (temperature) and morphological evolution of the silicon crystals are investigated.

Jan 1, 2005

By M. N. Pons, F. Ferrari, V. Houzelot, B. Laubie, A. Bani, Université de Lorraine-CNRS LRGP

"More than 400 plants in the world are able to accumulate nickel in their aerial parts at concentrations higher than 10 g per kg of dry biomass. Then, nickel (Ni) can be recovered from the biomass of these hyperaccumulator plants. Agromining is a chain consisting in growing such plants and recovering metal and has been developed thanks to the combined know-how of agronomy and hydrometallurgy. Plants can be grown on serpentine soils, containing rather high concentrations of Ni, on sterile heaps or on contaminated soils. This crop enables us to extract Ni from secondary resources, and to improve soil quality by lowering its metal content. For example, Alyssum murale can be grown at the field scale in the Balkans, at yields corresponding to 110 kg Ni per hectare.Hydrometallurgical processes have been designed from the lab scale to the pilot scale to produce nickel salts: ANSH (ammonium and nickel sulphate hexahydrate), nickel sulphate, acetate, etc. and so on. These salts are used for surface treatment and in the paint and chemical industry. Ni salts are prepared from ashes, after plant calcination. Processes are based on the conventional methods of hydrometallurgy: acid leaching followed by different precipitation steps. These processes will be presented, as well as the pilot scale design. A life cycle assessment has been performed and clearly shows the environmental interest of this approach as a potential part of an anti-erosion strategy. An economic assessment has proved process feasibility and the final step is the launching of a start-up. At the moment, the approach is widened to other metals (cadmium, cobalt) and rare earth elements (REEs)."

Jan 1, 2016

By A. Azizi, P. Blatter, A. Bouajila

"Due to the high reactivity of sulfide minerals in alkaline cyanide solutions, some parasitic reactions inflict a heavy gold surface passivation and excess cyanide consumption resulting in a dramatic decrease of the gold leaching rate. Atmospheric pre-oxidation was shown to be an effective tool to enhance gold extraction by preventing a passive film from forming on the surface of gold grains. This work aims to highlight efforts undertaken to determine: (1) how gold cyanidation is limited by passivation; (2) what are the reactions and mechanisms involved during gold cyanidation; and (3) how a better understanding of fundamental issues can be used to design a proper pre-oxidation strategy. INTRODUCTION Precious metals (PM), gold in particular, naturally occur in contact within a wide range of sulfide mineral systems. Hence, one of today’s most challenging R&D tasks consists in accounting for the presence of sulfides on the cyanidation behavior of gold. An important body of knowledge reveals that metal sulfides display a range of reactivities in alkaline cyanide solutions (Marsden & House, 2006). Such reactivities are acknowledged to inflict additional utility costs and loss of profits because they are accompanied with higher consumption of cyanide and/or formation of undesirable by-products that are often detrimental to gold leaching rates. Gold recovery in cyanidation is hampered by a multitude of factors, among others: (1) consumption of excess cyanide as a result of the formation of thiocyanate and dissolution of transition (Cu, Fe, Zn, etc.) metals (Habashi, 1967); (2) gold surface passivation by solid reaction products, e.g., Fe(OH)3 (Guo, Deschenes, Pratt, Fulton & Lastra, 2005), sulfur (Dai & Jeffrey, 2006; Jeffrey & Breuer, 2000;) or oxo and thiooxo (SbO33- SbS33-) salts in alkaline solutions (Guo et al., 2005). Because of their energy structure, most of the sulfide minerals exhibit semiconductor properties (Marsden & House, 2006). Therefore, the contact between constitutive sulfide minerals inside complex sulfurous ores entrains electrochemical phenomena in which sulfide dissolution is a genuine corrosion process (Azizi, Petre, Olsen & Larachi, 2010). For instance, galvanic interactions could be initiated between the various constituents within the ore and could substantially increase or decrease the reactivity of some of the associated minerals."

Jan 1, 2012

By Ian Thomson

OBJECTIVES OF EXPLORATION ? Prove/Disprove presence of potentially economic mineralization ? Keep on budget ? Minimize negative environmental impacts ? Gain a ?Social License to Operate? (SLO) WHAT IS A ?SLO? ? Granted by the local community ? Intangible, informal, non-permanent ? Has to be earned and then maintained ? Defined as ? Ongoing Approval (BSR and AccountAbility) ? Ongoing Approval, broad social Acceptance (Joyce and Thomson) ? Ongoing Acceptance (Nelson, and many others) ?Expression of the quality of a ?relationship?

May 1, 2010

By Larry T. Yano, Gerald T. Handford

"Tailings Engineering has the responsibility for planning and coordinating tailings disposal and for ensuring the stability of the tailings dyke. The inclusion of both the planning and geotechnical functions in one team has resulted in greater efficiency in the design and planning process. Major challenges in tailings disposal facing Syncrude are in the areas of: (1) sludge disposal; (2) instrumentation and monitoring; and (3) liquefaction. Meeting these challenges will have a significant effect on the cost effectiveness and reliability of the mining operation.IntroductionThe size of the tailings disposal operation has led to the establishment of a large engineering team devoted solely to the disposal of tailings. This paper discusses: the tailings disposal operation, the role of tailings engineering, the organization, inter faces, and the present and future challenges with respect to tailings disposal."

Jan 1, 1990

By V. J. Sopuck, O. P. Lavin, Ian Nichol

"A major challenge of contemporary exploration geochemistry is the development of procedures that can locate blind mineralization or mineralization that sub-crops below a cover of transported overburden, the composition of which bears no relation to the underlying mineralization. Over the past few years, the possible existence of diagnostic geochemical features in the country rock associated with volcanogenic massive sulphide deposits has attracted increasing attention both on the local mine scale and on the regional scale. In the present investigation, the nature of the geochemistry of a number of Archean greenstone belts of the Canadian Shield is examined to determine the feasibility of distinguishing productive from non-productive areas of copper-zinc mineralization. The results indicate that productive areas are distinguishable from non-productive areas providing consideration is given to the effects of igneous differentiation on rock compositionIntroductionArchean massive sulphide deposits are an important source of copper and zinc, and to a lesser extent silver and gold, particularly in Canada. As in the case of most other forms of mineralization, there is a continual need to develop new techniques that will improve the chances of success in the search for these deposits. The majority of Archean areas in the northern latitudes are overlain by a variable cover of glacial overburden. Considerable progress has been made in the development of new geochemical exploration techniques for use in glaciated terrain, based on the detection of anomalous dispersion in the glacial overburden. In certain situations, however, as in the search for blind deposits or in areas covered by glaciolacustrine deposits, overburden geochemistry offers little hope for success. In the case of massive sulphide deposits, one possible solution may lie in the detection of anomalous geochemical signatures in the bedrock. Recognizing this possibility, attention has been directed to the investigation of the nature of lithogeochemical dispersion associated with massive sulphide deposits on both regional and local scales, to establish the potential of lithogeochemistry as an aid in the search for these deposits."

Jan 1, 1980

By J. K. Szymanski

"RÉSUMÉPour maintenir de bonnes performances technique et économique dans l’exploitation par chambres vides (open stope) il est primordial d’assurer un contrôle efficace des limites réelles des chantiers d’abattage. C’est pour cette raison que, de plus en plus souvent, les opérateurs miniers utilisent un dispositif de laser (Cavity Monitoring System: CMS) qui permet de mesurer les dimensions réelles de chantiers en vue de calculer principalement la dilution et les pertes du minerai ainsi que d’autres paramètres. Malheureusement, il n’existe présentement aucune méthodologie commune, qui permettrait d’interpréter ces résultats selon les mêmes critères pour faciliter d’évaluations juste et précise de la réalisation par rapport à la planification en vue d’en apporter de corrections, dans les différentes opérations minières, si nécessaire. Dans la première partie du présent article on discute les principales séquences d’exploitation utilisées dans l’extraction par chambres vides. Par la suite, à l’aide des sections transversales et longitudinales on illustre toutes les phases des travaux miniers. Ceci en vue de permettre au lecteur de comprendre mieux c’est qui peut se passer effectivement dans les chantiers d’abattage. Par après on donne les définitions générales de principaux facteurs de performance technique. Finalement, l’exemple numérique, élaboré à partir des résultats de l’arpentage au laser effectué par la mine Bousquet 2 dans un chantier d’abattage, donne les détails concernant les définitions ainsi que les valeurs de nombreux facteurs de performance technique, qui pourraient être utilisés, par après, par les opérateurs miniers dans le suivi de leurs exploitations souterraines."

Jan 1, 1997

By R. Mckinstry, M. Rantapaa, T. Bolles

"Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput.Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore.Barrick Goldstrike’s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs."

Jan 1, 2005

By M. Bavand-Vandchali, F. Golestani-Fard, S. Khalili, S. Rowshanfekr-Fallah

In the secondary metallurgy of steel, the availability of ladles plays an important role in decreasing the production cost. The refractory lining, therefore, should satisfy optimized quality to grant higher heats. This paper reports the results of an investigation carried out in Iranian Mobarakeh Steel Company in order to increase the lining life of ladles by employing different types of MgO C and Al203 - Mg° - C. The zoning concept was used in replacing the conventional refractories either in slag line or the lower parts of ladle. The number of heats could be improved to almost two times as before. The results are explained in terms of refractory quality as well as zoning approach. The economical impact of this improvement will also be analyzed.

Jan 1, 2004