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By S Chew, A Bennett, N Di Giorgio, B Osborne

After relining one of two blast furnaces and enlarging its sinter plant in 2009, BlueScope radically restructured its Port Kembla steelworks operation in 2011, shutting a blast furnace and halving its total production. This drastic move in response to unprecedented raw material prices relative to achievable steel prices was like that of many integrated steelmakers worldwide facing similar challenges. The 2011 restructure also saw major changes in the amount and type of iron ores and ferrous burdens purchased, and a fundamental reappraising of ‘value’ in iron ores. This paper outlines the changes to raw materials purchases from 2011 to 2017, how BlueScope has responded to the changes in pricing and raw materials quality, the effect on the sintering and blast furnace processes at Port Kembla resulting from higher gangue content, some of the broad technical and economic challenges faced by steelmakers confronted with lower quality iron ores and how BlueScope is meeting those challenges.CITATION:Di Giorgio, N, Bennett, A, Osborne, B and Chew, S, 2017. Recent Port Kembla experience with iron ore use – sintering and blast furnace, in Proceedings Iron Ore 2017, pp 25–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Jacolien P. Wyethe

Zincor uses a Roast-Leach-Electrowinning circuit to process zinc sulphide concentrates. It also processes zinc oxide fume, originating from a slag smelting operation in the Democratic Republic of the Congo (DRC). Zincor achieved an average zinc recovery of 90.3% during the period January 2006 to May 2007. The bulk of the losses occurred in the iron and lead silver residues, both as soluble and un-dissolved losses. The un-dissolved losses in the iron residue constituted around 33% of the total zinc lost from the circuit, and were largely attributed to the presence of zinc-ferrite in the calcine used for neutralization during iron removal. As part of Zincor?s continuous improvement programme, the un-dissolved zinc losses in the iron residue were targeted by: the partial replacement of calcine with zinc oxide fume (from the DRC); and the preferential use of ?low-ferrite content calcine? as neutralizing agents in the iron removal circuit. These initiatives, coupled with other operational factors, resulted in a marked improvement in recovery to 92.6% during June to December 2007. The zinc oxide fume, directly fed to the circuit, required investigation of the halide rejection capacity of the Zincor circuit. Rejection of chloride via the magnesium bleed operation was considered adequate. Fluoride was mainly rejected via the iron (~70%) and lead silver (~27%) residues. Fluoride rejection via the lead silver residue varied significantly, probably as a result of variations in the sparingly soluble CaF2 content in the feed. The mechanism for fluoride rejection in the iron residues is uncertain. The fluoride rejection capacity of the Zincor iron residue (comprising of mainly jarosites, schwertmannite and ferrihydrite) at 2 ? 4 mg/L F in solution, was estimated at 0.14 ? 0.19 kgF/tFe residue.

Jan 1, 2008

By D. P. Cook, Jr. Jones, J. W. Evans

"It is well understood that the flow of liquid metal in the mold region of the caster can have a notable effect on the overall solidification behavior in aluminum casting. Previously our group has characterized the flow in this region in a water model, using particle imaging velocimetry. The flow is significantly effected by the specifics of the metal delivery system, i.e. size, geometry, used during the cast. Recently, a time-averaged 3D numerical model of the nozzle, combo bag and sump region has been developed and its validity has been tested against experimental data. Cases were run for different sized combo bags as well as bags that have been blocked. The results show satisfactory agreement between the physical and mathematical models.IntroductionFluid flow in the head of an electromagnetic (EM) and direct chill (DC) ingots has been shown to effect many important operational parameters in casting such as superheat removal, macrosegregation, and hot cracking. In most cases, the momentum from the nozzle is diverted through a delivery system, termed a bag, before entering the mold region. The specific geometries of the bags vary widely from operator to operator suggesting that there is still some question as to the optimum design. Several studies [1-4] have been carried out to understand the influence of the bag design on the solidification behavior in aluminum casters. However, few studies have included numerical prediction with experimental verification. Unfortunately, many simulations performed today still do not accurately account for flow in such devices.Recently, a significant amount of research into the flow resulting from the metal delivery systems has been performed [5-8]. The thrust of this research has been characterizing the flow patterns by a measurement technique called particle imaging velocimetry. The data suggest that the method of delivering the liquid metal into the mold region has a significant effect on the nature of the flow. With a detailed set of quantitative data from a water model, a numerical model can be built and tested to ensure a proper description of the flow field. The computational model used in these simulations is designed to represent a laboratory scale model of a caster in which ""combo"" bags were simulated. Such bags are mostly of a densely woven glass fiber material with low permeability to aluminum. ""Windows"", of a more open weave, permit aluminum to flow from the bag, see Fig. I. Two different sized combo bags were modeled, each subject to two different outflow window configurations. Furthermore, experimental measurements [9] were used to validate the model results."

Jan 1, 1999

Cook Colliery currently mines in the Argo Seam, beneath old workings in an overlying seam. The Argo seam is up to 4.8 m thick and a continuous haulage system behind an ABM25 is used to develop first workings. Current partial secondary extraction utilises floor stripping and pocketing or sumping first working pillars on retreat. The following paper summarises this recent secondary extraction experience, particularly from a geotechnical perspective, but also considering production and ventilation issues. Outcomes and learnings are presented for mining in this challenging and close multi-seam environment. The sealed castor seam workings are within 20 m, and vary from unmined areas to large first working pillars, to partial extraction panels and full extraction panels. High stress remnant pillars and goaf-edges are notable mining considerations. The mining environment is further complicated by faulting, thrust zones and weak laminated roof.

Nov 25, 2010

By Richard H. Oitto

With increased interest and urgency for coal mine safety and the passage of the Federal Coal Mine Health 'and Safety Act, the Bureau's research effort in roof control has been greatly expanded. One new project, the subject of this paper, concerns improving conventional roof bolting and has been involved with the effects of different variables on the performance of roof bolt expansion anchors. These include types of expansion anchor, rock type at the anchorage horizon, borehole roughness, rate of torquing a roof bolt to set the anchor, installed tension, bolt length, and relative humidity fluctuations. For this work, two types of experiments were carried out. One was concerned with tension loss in bolt-anchor assemblies and simulated anchor performance in a static roof. The other dealt with anchor slippage as tension was increased and simulated anchor performance in an active roof. Trials were made in the laboratory under controlled conditions so that factors suspected of affecting expansion anchor performance could be selectively studied. Because of the natural variability in rock and the fact that most expansion anchor components are essentially rough castings or forgings, the experiments were designed to permit using analysis of variance techniques for analyzing data. Thus, in this paper, "significant" means statistically significant.

Jan 1, 1972

By Ming Ju Liu

China has been suffering from the most serious coal and gas outburst accidents. The situation has become worse than ever with the mining of deeper coal seams at higher production rates in a more complex underground mining environment, in order to meet the huge national demand for coal-fuelled power plants. In the year 2007 alone, more than 30 outburst accidents occurred in underground coal mines with a death toll of 258, and in the year 2008, as of May 22, nine outbursts have already occurred in Henan, Hubei and Chongqing, killing 68 workers. At the same time, China also experienced new trends of coal and gas outburst accidents since its coal production boom in the year 2001. These trends are of great importance for government agencies, coal mine owners and operators to take initiative and effective measures to prevent and control the occurrence of coal and gas outbursts in China?s widely spread outburst prone mining areas. This paper presents outburst data of China coal mines since 2001 and describes new trends of outburst occurrence in recent years, which include outbursts coupled with shocks or rock bursts of competent roof, outbursts in mines under development, outbursts in new mines and mines that have never suffered outbursts before, outbursts in mines that are believed to be of low gas content as well as outbursts in more long-wall faces. Based on the observation of outburst occurrence in China in the period from 2001 to 2008 as well as mining and geological conditions, detailed analysis of the possible causes that led to those new trends of outburst accidents is conducted. The analysis helps shed light on possible future remedies and the necessary measures to alleviate or eliminate outburst accidents in underground coal mines. Suggestions are put forward on future studies that could be of interest to national and provincial government agencies regarding strategic policies, proper technical management practice, identification of outburst prone coal seams, online monitoring of impending outbursts as well as prevention and control measures.

Jan 1, 2008

AT A MEETING of the Shareholders of the Russo-Asiatic Cons. Ltd., in London, Oct. 23, 1922, LESLIE URQUHART, chairman of the com- pany made the following statement:* I come now to our recent negotiations with the Soviet Government and to the agreement which has resulted from them. You will remember that the conference at The Hague broke up without having achieved anything very definite. It was not, however, a failure. It elicited from M. Litvinoff an offer which will, I think, come to be regarded as a milestone in the progress of Russia from a ruinous and unpracticable Communism towards a modified form of capitalism. The offer made by M. Litvinoff at The Hague amounted in effect to this: that in return for political recognition on our part the Soviet Government would first acknowl-edge its liability for Russia's national foreign debts, and, secondly, would give the original foreign owners of property in Russia effective compensation. A very great advance that. It showed-and there have been many other signs to confirm it-how real and persistent has been the internal evolution of Russia during the past year from Marxism to the economics of the Western world. I will not now detain you with the reasons why M. Litvinoff's highly promising and significant offer came to nothing. The fact that it had been made and the further fact that The Hague Conference had separated indefinitely were the important things. The first fact seemed to indicate that the Soviet rulers, after all, proved to be people with whom one could do business. The second fact rather emphatically showed that the way to do business with them was not by unwieldy poly-glot conferences of ministers, officials and experts representing a few dozen different governments and a few dozen different sets of national interests. That method had been tried at Genoa. It was tried again at The Hague. Each time it failed, and having failed it left the road clear for a simpler and more direct approach.

Jan 12, 1922

A methodology has been developed and demonstrated to be effective in reclaiming surface-mined land for a forestry post-mining land use. The Forestry Reclamation Approach (FRA) has been applied, almost exclusively, to flat or gently rolling surfaces. One of the primary steps in the FRA is to loosely grade the top 1.22-m (4-ft) of soil or substitute root growth medium to avoid excessive compaction. Concern has been expressed by regulators and the public that loose grading on steep slopes could lead to slope failures, which is one of the issues that SMCRA sought to correct. A field investigation was conducted at a steep-slope contour operation in eastern Kentucky to test the applicability of FRA in this setting. Final grading was performed according to FRA standards. The surface consisted of two distinct substitute rooting media. One was unweathered gray sandstone and the other was a combination of gray sandstone, brown sandstone, and topsoil. A variety of native hardwoods was planted following the FRA guidelines. The slope was instrumented with 70 survey monuments to monitor for mass movement. The reclaimed spoil was also characterized using bulk density and penetrometer resistance methods. The characteristics of both spoils are similar to those observed on flat to rolling surfaces where the FRA has been used and, after one year, approximately 70% of the trees had survived. There has been no major mass movement of the slope and slope stability analyses indicate that the application of the FRA has little impact on the overall stability of the slope.

Jan 1, 2011

By K. Burke, K. L. Myers, R. Espell

Barrick Goldstrike’s (Goldstrike) AA Heap Leach Pad is an HDPE lined facility used for gold recovery from low grade ores using conventional cyanide heap leach technology, operated from 1987 through 1999. Goldstrike prepared a unique reclamation plan for the AA Leach Pad Facility to provide for a cost-effective, environmentally sound facility closure and to fulfill the State of Nevada’s closure requirements. Traditional Nevada leach pad closure has involved rinsing to reduce cyanide concentration to an acceptable level, followed by reclamation. However, certain metals and compounds are not typically reduced by rinsing and some constituents may increase in concentration with rinsing. A closure scenario to effect limited infiltration through installation of a capillary cover for the leach pad was developed. The capillary cover was constructed by placing a fine-grained layer above the coarse-grained spent leach material to create a capillary break. In an arid climate such as Nevada, the fine-grained layer will rarely reach full saturation and the cover will be able to store water during precipitation and allow removal of water through evaporation and transpiration (ET) during the growing season. A 1.22 m (4 ft) cover thickness was selected as the optimum design cover thickness. The drainage network on the surface of the re-contoured AA Heap Leach Pad was specifically designed to enhance the revegetation, reclamation, and sediment yield control aspects of the AA Heap Leach Pad closure, while resulting in a natural looking surface, compatible with the surrounding topography. Adjacent natural topographic features were used to establish target design parameters for re-contouring and erosion control design.

Jan 1, 2001

A unique sluicing process for recovering tailing impounded in a valley was developed by Electrolytic Zinc Company of Australasia Ltd., West Coast Mines, Rosebery, Tasmania.Earthmoving equipment could not be used as most of the material to be recovered was semi-fluid. A conventional sluking method was also impracticable as there was no suitable working face from which the process could be commenced.Operations started from a flat surface, using special techniques for sinking through the tailing and establishing producing working faces as the sinking process continued.After about 2 years the bottom of the dam was reached and conventional sluicing methods could be used.

Jan 1, 1973

By J. L. Uhrie

A potentially cost effective technique for the reclamation of heavy metal contaminated soils and sediments involves the technique of froth flotation. Heavy metals sorbed to clays in the soil may be sulfidized by the introduction of sodium sulfide and floated using a dithiophosphate collector. Separations were obtained where up to 78% of all copper ion was removed from the system. Selected samples were floated in a column cell but little advantage was seen.

Jan 1, 1996

By C. E. Davis

The Jamaica Mining Legislation requires the bauxite companies operating in the island to reclaim all mined-out lands (except those legitimately excluded) to the level of agricultural or pastoral productivity, which existed prior to the commencement of mining. If it is not possible to reclaim a mined-out area the companies are required to reclaim an equivalent area of some other land which had not previously been used for agricultural purposes, or alternatively, pay to the government the sum of $120 (US) for every acre of land mined in the particular sector. In the seventeen years since the programme commenced the companies have in general chosen to reclaim most of the mined-out lands, rather than the cheaper alternative. However, the ultimate success of the programme will depend not only on actual reclamation per se but moreso the productivity of the rehabilitated lands. There are a number of reasons why the accent has to be placed on productivity of the lands. The first is that Jamaica is a small country (4,450 square miles) with a population of nearly 2 million people. Because of its mountainous terrain it is estimated that only 35% of the land area is cultivable in crops and pastures; hence this limited area, as well as that which can be reclaimed, must be made highly productive in order to support local and export demands. The Mining companies own over 200,000 acres of land, and of this acreage, it is conservatively estimated that about 75,000 will be affected by mining and will be reclaimed. As such, the use of the land after mining can have an important bearing on Jamaica's future agricultural productivity. The second reason is that a significant amount of the land now owned by the companies was purchased from thousands of small

Jan 1, 1972

Greater use should be made of lineations in investigations of the engineering properties of rock masses and in structural studies guiding prospecting programmes.A prominent alignment of elongate mineral grains and stretched pebbles usually marks the primary direction in which metamorphic rocks have been extended by flow. In local adjustment zones separating masses that have extended different amounts, this lineation has been a direction of slip. Kinks and crumples resulting from this slip lie in secondary lineation directions transverse to the primary mineral lineation.During deformation relatively mobile materials move into dilatant zones caused by irregularities in primary flow directions. This secondary movement transverse to lineated, primary-flow directions is the cause of crenulations and folds with axes parallel to flow lineations.INTRODUCTIONThe arrangement of inequidimensional particles in rocks is rarely statistically random. Platy minerals tend to be parallel to bedding and foliation planes. Elongate particles and linear structures lie most frequently in certain lineation directions. The types of elongate particles in lineated rocks include needle and blade shaped mineral grains, sheared out segregations, and stretched pebbles, amygdules, and aolites.Crenulations and kinks are the most common of the linear structures involved.Faint lineations are readily overlooked. Even strong lineations have been ignored. This is unfortunate as even weak lineations may be important.Use of lineation information Well-developed lineations influence the mechanical properties of rocks. Quarry workers have long known that the mechanical properties of rock masses vary directionally...

Jan 1, 1965

By D J Maconochie

The use of rock bolts as permanent support has been prohibited by client specifications in several recent large tunnel projects in Australia. The justification for this appears to lie in concerns with proper and verifiable installation procedures rather than concerns with the intrinsic durability of the corrosion protection systems. However, in civil tunnels, preventing the use of permanent rock bolts for long-term support results in the use of cast in place concrete lining which in some instances would otherwise be unnecessary.

Mar 8, 2011

By Michael Quadagno

Hudson River Pier 86, home of the historic USS Intrepid Aircraft Carrier and the Intrepid Sea-Air-Space Museum, is currently undergoing a $30M reconstruction. This project involves the demolition of the old timber pile supported pier and construction of a new 150 ft wide by 782 ft long concrete pier, built over the footprint of the old piles. The new pier consists of steel pipe piles, precast concrete pile caps, and a composite deck, made up of precast, prestressed concrete planks and cast-in-place concrete topping. This paper focuses on both the structural design and construction of the new pier, with emphasis on the pile foundation. Pier 86 is unique in that it is required to resist the extremely high lateral loads imposed on it by the permanently moored 898 ft long aircraft carrier during severe storms. A total of 360 steel pipe piles support the new pier. These piles, which are 24 in. in diameter and range in length from 58 ft to 175 ft, were driven down to bedrock. The piles, each having 200 ton allowable capacities, work together to resist the significantly large lateral loads exerted on the pier by the ship. The installation of the piles was unique in that all the piles, including the ?super-longs?, were fabricated to-length offsite, delivered to the site via truck and barge, and installed in one piece, eliminating the need for field splicing. The Pier 86 reconstruction will be completed within an extremely aggressive 18 month schedule, from January 2007 through June 2008. The refurbished aircraft carrier Intrepid will return home in September 2008, and the grand re-opening of the pier will be on Veteran?s Day 2008. This paper provides a case history for owners, government agencies, engineers, and construction professionals that will be faced with the challenges of designing and building new piers.

Jan 1, 2008

By M. Kumral

A mining system consists of many sub-systems such as drilling, blasting, loading, hauling, ventilation, hoisting and supporting. During mining operation, these sub-systems may experience various problems that stop the operation because of possible environmental equipment and safety issues. In order to ensure delivery contracts in the required quality and safe mining medium, the operation should be, at least, performed in the specified reliability level of the system. If the system reliability decreases below the specified level, there will be safety and financial losses for the mining company. Therefore, the mine should be maintained by a reconstruction procedure to guarantee the operation continuity. Given that each sub-system has a different reliability function and maintenance cost, the determination of reconstruction time will be a complicated decision making problem. In this paper, the determination of reconstruction time is formulated as a nonlinear optimization problem and solved by genetic algorithms (GA). A case study was conducted to demonstrate the performance of the approach for an underground operation. The results showed that the approach could be used to determine the best action time. Keywords: mining system; genetic algorithms; reconstruction time; reliability analysis

Jan 1, 2009

By Sidney Snook

FLUORSPAR production is the most important industry in a compact area in southern Illinois and western Kentucky bordering the Ohio River. Producers' activities do not usually figure much in the mining news of the country, so that few know that the last year or so has been an unusually active one. Mine shipments more than doubled in 1939 compared with the poor year 1938. The average price changed but little, though it is now about one-sixth higher than at the beginning of last year. The outbreak of war in Europe a year ago lent an immediate stimulus to the industry, though only about 15 per cent of the domestic consumption is normally imported, thanks to a tariff of $8.40 per ton, equivalent to about 30 per cent ad valorem. Be- cause of the increased production and many expansions and improvements in the mines and plants, the period since the beginning of 1939 has been the most important one for the industry in the last 15 years.

Jan 1, 1940

By Donald W. Stever

In 1995 I was asked to participate in a litigation matter between a corporation and its insurance carriers concerning insurance coverage for remedial costs at a large, environmentally contaminated closed-down former industrial facility. One of the buildings on this site became known to the lawyers representing the company as “the infamous Building 8”. This building housed millions of documents retrieved from various locations at the facility while it was being shut down. It became apparent that the facility management had no document destruction policy, and thus Building 8 contained internal memoranda, notes, copies of correspondence, permits, operating records, inventory records, and the like from fifty years of operation. Needless to say, some of these documents, all of which were subject to discovery by the insurance companies in the litigation, contained material that was less than helpful to the company’s case. Of course, there were also a few helpful documents, but the overall usefulness of these records was outweighed by the negative impact they had on the conduct of the litigation. A second example involves e-mail. Several years ago, acting on an anonymous complaint that we later discovered was made by a disgruntled former employee who had been fired, a small army of federal environmental investigators descended on a client’s operating facility and, armed with a search warrant, literally commandeered the facility’s EH&S department. The investigators impounded the computers of the EH&S personnel and extracted all of the data from the hard drives of those PCs, as well as all EH&S related files from the hard drives of several servers used by the facility. These computers contained many years’ worth of stored e-mails, draft letters and memoranda, and other documents that provided grist for a four and one-half year criminal grand jury investigation of the facility and its EH&S staff. Both of these companies would have benefited from following a rigorous, enforceable, corporate records policy. Here is a third problem. My client had, during the 1960s, made a brief, and unprofitable foray into the nuclear fuel processing business. It ultimately sold the subsidiary, and was forced to give the purchasing company a broad indemnity against future liability. As might be expected, years later the facility was found to have considerable soil and ground water contamination both by chlorinated solvents and low-level radioactive material. Several years into the remediation program, my client discovered a tractor-trailer load of files, apparently removed from the subject facility, sitting in a parked trailer in a company-owned lot 300 miles away from the facility, where they had been for nearly thirty years. These documents were not helpful to the client, but had to be reviewed, at considerable cost, by paralegals. Moreover, several of the boxes turned out to have been mildly radioactive, setting off a chain of health and safety issues that consumed tens of thousands of dollars of legal expenses before they were resolved. Today, formal, enforceable corporate records management programs have become an extremely important element of overall corporate management. What was for most of the last century little more than a low level warehousing function is now a critical, actively managed, operating function that affects every level of corporate management. The rapid assimilation into corporate culture of electronic document management and the prevalence of e-email as the primary means of internal communication have created records management complexities the likes of which were not even conceived of fifteen years ago. Record preservation and destruction are no longer matters that can be handled on an ad-hoc decision making basis. Because of regulatory requirements affecting various classes of documents and the litigation consequences of ad hoc retention and destruction of corporate business records, and the need to have the ability to quickly retrieve documents in either a litigation or business negotiation context, a set of records management norms have evolved over time that have become the core elements of virtually every corporate records program. However, notwithstanding the existence of a set of norms (which are the basic elements of a

Jan 1, 2005

By A. Pawelczyk, D. Hreniak, E. Zych, W. Strek, K. Grabas, A. Ostrowski

"Nowadays recycling became an important rare earth elements (REE) source, which allows to reduce their demand for extraction from natural deposits. At present, the used fluorescent lamps and old type TV or computer monitors kinescopes are selectively collected and undergo processing in the system of recycling. It has been estimated, that utilization of such waste would be sufficient to cover the REE demand for the next 5-8 years. In the developed process, the luminophores were separated from the electronic and electronic waste materials, and processed by hydrometallurgical methods to obtain concentrated REE in form of oxides. INTRODUCTIONInternational Union of Pure and Applied Chemistry (IUPAC) defines the rare earths as a set of seventeen chemical elements, specifically the fifteen lanthanides plus scandium and yttrium. They are considered the most important indicators of the developed technologies and techniques. Rare earths are used, amongst others, for the production of magnetic and superconducting materials, ceramics, lighting, catalytic converters, advanced electronics and alloys. The demand for RE continually increases, similarly to many other primary raw materials. Globalization, the growing demand for limited resources of raw materials, the policy of the countries controlling the raw material market and the economic crisis became a spur for new programs of socio-economic development of the European Union (EU), with particular regard to EU safety for commodities in intermediary as well as long-term horizons (COM 2008), COM 2011).EU countries import most of metallic and chemical raw materials important for their economy. In 2008 a detailed program named Raw Material Initiative was announced. The increase in demand for most raw materials having special importance for the development of technology, and access to of raw materials security of supply affect the future economies of the UE member states and other developed countries."

Jan 1, 2012

By R. T. Jones

Base metals and platinum group metals can be collected in metallic alloy form, via a wide variety of smelting processes. The recovery, or degree of collection, of the valuable metals is a function of the extent of reduction in the furnace, which, in turn, is indicated by the fraction of iron present in the feed materials that report to the alloy. An equation has been developed that relates the recovery of various metals (such as Ni, Co, Cr, and PGMs) to the recovery of Fe. This recovery equation (for each metal) is characterized by a single parameter (K?) that can either be empirically fitted to the data, or expressed in terms of the equilibrium constant and the ratios of the activity coefficients involved. Data from a number of varied DC arc furnace campaigns are presented to illustrate this behaviour.

Jan 1, 2009