Search Documents

By William H. Waggaman

CURTAILMENT of the mineral industry as a whole undoubtedly will follow world peace, but the output of certain minerals should pursue a course well above the average on any curve of probable output projected beyond the trends exhibited through 1939. Without speculating on industrial conditions in the pending recomversion period, demand for fluorspar should be greater than before the war because of these factors, introduced by or resulting directly from military necessity: (1) Discovery and development of new deposits. (2) Improved technology in benefication. (3) New and expanded uses for fluorspar and its derivatives. The steel industry has been and continues to be the greatest consumer of fluorspar, and it wag largely to meet the wartime needs for steel that the domestic fluorspar industry has been expanded so greatly. Not only were the search for and development of new deposits of this mineral considered esstinal but the marginal nature of some of the,c- domestic deposits made it necessary to improve mineral dressinc and processing techniques to utilize them

Jan 1, 1945

By R. S. Handy

THE properties of the Patiño Mines and Enterprises Consolidated, Inc., a New York corporation, are near Llallagua in the department of Chayanta in the west central part of Bolivia, South America, about 80 miles southeast of Oruro and 250 miles southeast of La Paz, the largest city in Bolivia and its virtual capital. The properties are accessible by railroad from three points on the west coast-from Mollendo, Peru, across Lake Titicaca, from Arica by way of La Paz, and from Antofagasta, Chile. The latter route, although the longest, is recommended by the companies as affording a more gradual introduction to the high altitudes; the mine being 13,000 ft. above sea level. The company operates its own railroad from its properties at Uncia to Machacamarca on the Chile & Bolivia R. R., a distance of 60 miles. This railroad is well equipped and well operated, and its location among the mountains surrounding Uncia represents excellent engineering skill. In fact all of the railroads, although they are of only a meter gage, are remarkable for the excellence of their construction, the arrangement of their dining and sleeping cars and the precision of their operation. There is only one drawback to rail- road and hotel accommodations and that is the absence of heating facilities, which does not seem to affect the natives but keeps a tenderfoot's teeth chattering continually. The company is a consolidation of the Patiño company, owning properties at Uncia, with the Compafiia Estanfera de Llallagua, a' Chilean corporation owning contiguous properties at Llallagua. Before the consolidation these companies were deadly enemies, and there still remain at the surface plant at Uncia the fortifications and underground defences provided during the warfare between the two factions. Also, in the Azul, or "Blue" tunnel at the junction line between the two properties is a strong steel barricade still bearing marks of the bullets fired during the various armed tilts between the workmen of the two companies. The headquarters for the mining operations and the milling plant have been moved since the consolidation from the original location at Uncia to the Llallagua side of the mountain, where the Chilean company's operations were carried on. The historic old town of Uncia, with its massive stone buildings of Spanish design, is a wreck, while the Llallagua side is being rapidly built up with modern structures.

Jan 1, 1929

By C. A. Fisher

THE Salt Creek Oil Field of Wyoming occupies a unique position among the major oil fields of this country. Many years before the beginning of actual production in this area, in 1911, it had attracted country-wide attention as a district holding oil possi¬bilities. Even foreign capital, mainly French and Belgian, had sought out this district as having oil values and spent many thousands of dollars 'in an effort to acquire property rights' in this field which was very largely located on the public domain. Owing to inadequate laws governing the acquisition of oil lands on the Federal domain and a careless practice having grown up among oil land locators of that time, a complicated title situation quickly developed in Salt Creek. This condition of uncertain titles together with the isolation of the field from industrial centers were doubtless the two most potent factors in retarding its early development. After actual production began in 1911 governmental regulations, suits between the government, and the locator, disputed ownerships between locators and claim and counterclaim continued to retard the field's development. It is believed that the title situation in the Salt Creek Field, where potential values of such magnitudes were involved, was responsible more than any other factor for the ultimate passage of the government leasing act in 1920 affecting all oil lands on the Federal domain.

Jan 1, 1925

By Charles Will Wright

Brief descriptions of the occurrence of the various deposits of strategic minerals then known in South America are published in "The Mineral Deposits of South America," by B. L. Miller and J. T. Singewald, 1919; in "Ores and Industry in South America," by H. F. Bain and T. T. Read, 1934; and in many publications on the individual countries. To give a gen.era1 idea of the situation today and possibilities for future output of strategic minerals in several of the countries, the following notes are offered. All tonnages are in metric units.

Jan 1, 1940

By E. W. Davis

DURING late years, the proportion of beileficiated iron ore shipped from the Lake Superior District has increased very rapidly. By benefication is meant washing, screening, drying, sintering or any process by which the grade or structure of the crude ore is improved before shipment. In 1915, only 3,000,- 000 tons, or 9 per cent, of t6e total Minnesota shipment was beneficiated ore, compared with 13,500,000 tons, or 35 per cent, of the total Minnesota shipment in 1925. This increase is, of course, due to the fact that iron and steel can be made more cheaply after beneficiating these ores than they could have been had these ores not been so treated. Fundamentally, however, several causes contribute to the necessity for beneficiating iron ores, such as depletion of the reserves of high-grade ores, the iron ore leasing systems and taxation methods and, at the smelting plants, a better understanding of blast-furnace operations, increased operating costs and increased sulfur content of blast-furnace coke. As economic conditions change, it is by no means certain that the proportion of beneficiated ore shipped each year is going to continue to increase. Undoubtedly some of the beneficiation operations are not economically sound at the present time and what the future has in store for the iron ore industry is problematical. Generally speaking, the cost of fuel for blast-furnace operations will increase as time goes on and in order to continue to produce cheap iron and steel, some of the other costs must be lowered. Freight and labor rates probably can- not be reduced. The cost of producing iron ore cannot be reduced much below the present price. It therefore appears that the best opportunity for maintaining iron and steel prices at their present level in spite of in- creased costs of labor and raw materials is to use. less or cheaper raw materials. This, of course, contemplates an improvement in metallurgical processes all along the line and, as a matter of fact, we can confidently expect these improvements because scientific investigations will undoubtedly be even more productive in the future than they have been in the past.

Jan 1, 1926

By E. L. BROKENSHIRE

FLUORSPAR, a little known non-metallic mineral, referred to technically as fluorite, chemically as calcium fluoride, is a compound of calcium and fluorine in the ratio of one molecule of calcium to two of fluorine. By weight it is composed of 51.3 per cent of calcium and 48.7 per cent of fluorine. Its specific gravity is 3.2. It is brittle, has a hardness of four and can be easily scratched with a knife. It weighs about 200 Ib. per cubic foot and has a melting point of 1650" F. The color of fluorspar ranges from pure white and opaque white, according to its purity, to various hues of yellow, green, pink, lavender, blue and brown, to bluish black. Although the lumps have color, when ground the fluorspar becomes pure white. The reason for this is because the mineral usually carries no fixed pigment, the color being produced by the re- fraction of light rays within the crystal structure and small quantities of organic matter which readily oxidizes. It crystallizes in the isometric system with perfect octahedral cleavages.

Jan 1, 1929

By H. E. McKinstry

LIKE nearly everything else, mining geology has been reconverting. Many geologists had been in military and other government service. Many more, with mining companies, had been working primarily toward increasing production from known reserves. All of these are turning now toward their normal peacetime endeavor-the search for new ore; for most mining companies, finding themselves with accumulated deficits in development work, are more than ready to go ahead with their postwar plans made a year or more ago but still stalled at the close of 1945 for lack of man power. These plans include not merely development in the old home camp but also wide exploration for new prospects both domestic and foreign. Most of the large concerns have geologists and engineers in the field in the United States, despite the outlook for higher mining costs here, and at least half a dozen strong American companies are already investigating opportunities abroad, notwithstanding past unhappy experiences in certain Latin-American nations which have welcomed capital but later found means of preventing investors from reaping the reward of their enterprise. A few of these new foreign expeditions are following well-planned programs, but too many, in their haste to get any sort of footing, are proceeding without well-considered policy. with the result that their geologists can do little more than desultory scouting.

Jan 1, 1946

By J. J. Jakosky

The strategic importance of the metallic minerals in our industrial economy, and the declining rates of discovery have focused attention on means of exploration for new mineral deposits. A consideration of exploration techniques leads to an attempt to evaluate the effectiveness of geo- physics as a tool for mining exploration. One means of evaluation will be to compare the use of geophysics in petroleum exploration with its possible uses in mining.

Jan 1, 1949

By Nikhil Dhawan, Débora Moreira, Yogendra Pratap, Himanshu Tanvar

A glauconitic siltstone sample with a potash content of 10% is investigated as a potential potash source. The fine grain structure comprises potash bearing phases of glauconite, muscovite, and microcline. The as-received samples showed poor dissolution ~ 5%. Planetary ball milling was attempted for the dissociation of the underlying silicate structure for the potash release, and ~ 60% potash was obtained after 12-h milling. Mechanical activation (8 h, 60% NaOH) prior to heat treatment (600 °C, 30 min) was found successful in recovering more than 95%K values from glauconite. The final residue consists mainly of quartz, indicating a complete breakdown of the silicate matrix. The mechanical activation process followed is simple, adaptable, and less energyintensive compared to existing methods.

May 4, 2020

By Alex Salvador

El Comisionamiento de una planta concentradora es un proceso secuencial ordenado y adecuadamente organizado de pruebas de operación con carga, que permite llevar a los diferentes equipos a su capacidad de diseño. Consiste en un proceso de arranque de equipos, seguido de un incremento progresivo de tonelaje de acuerdo a los criterios y protocolos del fabricante.

Sep 29, 2023

By Mike Johnson, Niels Verbaan, David Dreisinger

The Search Minerals Foxtrot project in Labrador is a surface deposit enriched in the highly sought after heavy rare earth elements. Early metallurgical work investigated beneficiation of the rare earth content of the Foxtrot resource using flotation, gravity separation and magnetic separation. The concentrate was then processed by acid baking and water leaching to produce a REE leachate for purification and recovery. The Search Minerals Direct Extraction Process was developed through bypassing the beneficiation process and directly acid treating a coarse crushed ore material prior to water leaching. The result is a simple, low risk technical process for direct recovery. Concurrently, the treatment of the water leach solution was modified to produce a high grade (98.9% total rare earth oxide) product for refining.

Jan 1, 2016

By H. W. J. P. Neomagus, J. R. Bunt, D. L. Botha, N. T. Leokaoke

Coal briquetting traditionally makes use of high-dosage, nonpolymeric binders (such as coal tar pitch or molasses) or polyvinyl alcohol (PVA) at low dosages for the binding of fine and ultrafine coal. Due to constraints associated with the manufacturing and cost of PVA-bound briquettes, a novel polyacrylic binder was developed that could possibly be added in low dosages at room temperature. A set of formulations of two polyacrylic components (components A and B) was developed, from which an optimal binder mixture was determined. This formulation comprises 40wt.% component A and 10wt.% component B with a 0.04wt.% cross-linking additive, and the balance water. The uniaxial briquette compressive strength was used to obtain the optimal binder mixture. The binder mixture was added to the coal powder in dosages from 0.1 to 1.2wt.%. Mechanical tests and thermogravimetric analysis in an oxidized environment at a maximum temperature of 930°C were conducted. Binder-bound briquettes were compared to binderless briquettes and PVA-bound briquettes. Briquettes made from the polyacrylic formulation had uniaxial compressive strengths double that of the binderless briquette yield strength, as well as the minimum recommended compressive strength of 0.375 MPa. The organic binders did not affect the combustion of the briquettes, since the results compared well with the binderless briquettes. The polyacrylic formulation is considered to be a possible substitute for PVA in terms of mechanical and thermal properties and raw material cost.

Mar 1, 2021

By Daniel Wild, Tobias Scheffer, Marvin Laugwitz, Martin Jochum

Leveling is a standard process in the rolling mill to eliminate flatness deviations. The process layout is based on models and the leveling result depends on the accuracy of the material parameters in these models. Even small deviations from the correct assumptions can have a major effect on the final flatness. Thus, after leveling the products may look optically flat, but subsequent to a final cutting process springback occurs due to residual stresses. The objective of this work is to analyze the influence of material parameters and gravity on the flatness after leveling. To evaluate the sensitivity of the process, an FE parameter study is exerted that reveals the influence of fluctuations in material properties in the case that the leveling setup is fixed. Gravity is neglected to not conceal flatness deviations. Examples of this study are rerun in a further step under consideration of gravity to also analyze its influence on the resulting flatness and residual stresses. Finally, to analyze the consequence of the residual stresses, all information of the plate from the previous step are transferred while gravity is suppressed to prompt springback. This study revealed that slight deviations of the material properties can lead to uneven plates in simulations where gravity is not considered. If gravity is taken into account, the unevenness is concealed and the plate seems flat. A springback simulation of the same plate shows that strong residual stresses are still present and would lead to unevenness if e.g. the plate were cut.

Oct 1, 2019

By Solange Kazue Utimura

As placas de circuito impresso (PCIs) dos resíduos eletroeletrônicos (REEEs) possuem diversos metais na composição. A recuperação desses metais tem incentivado as pesquisas inovadoras no seu processo de extração. Como alternativa de recuperação de metais das PCIs de forma sustentável optou-se pela biohidrometalurgia envolvendo a fase extração. O presente trabalho avalia a biolixiviação do cobre na presença de duas cepas bacterianas distintas em PCIs de REEEs provenientes de impressoras obsoletas. As PCIs foram caracterizadas mediante as técnicas analíticas de espectrometria ICP-OES e de fluorescência de Raios X (FRX) para determinar os elementos químicos presentes na amostra inicial. As cepas utilizadas na lixiviação bacteriana foram Acidithiobacillus ferrooxidans (AF) e Leptospirillum ferrooxidans (LF), cultivadas em meio de cultura T&K. Os ensaios de biolixiviação foram realizados em incubadora orbital, com velocidade de rotação de 170 rpm, temperatura de 30 oC, volume de inoculo de 10% (v/v) e densidade de polpa de 30g/L. A técnica empregada na concentração de cobre da solução após a biolixiviação foi a FRX. Foi possível determinar que a cepa AF apresentou uma extração de 100% de cobre em 8 dias em comparação com a LF na qual foi observado que a extração de cobre foi de 100% em 5 dias.

Oct 30, 2017

By S. N. Dixon

"Maximizing the value of each tonne of processed ore is the goal for all operations. Cyanidation processing of gold-copper ores has been challenging since its first use in 1889. The current practice treats a bleed or the total flow of mill solution to recover copper as copper sulfide (by sulfidization, acidification, recycling, and thickening), or to recover the cyanide (by acidification-volatilization neutralization). The process presented uses the adsorption of copper cyanide by carbon and the selective elution of copper from carbon to concentrate copper into a smaller stream. Copper contained in the smaller stream is precipitated as copper cyanide.RÉSUMÉ Toutes les exploitations ont pour objectif commun d’optimiser la valeur de chaque tonne de minerai traité. Depuis sa première utilisation en 1889, la méthode de traitement par cyanuration des minerais aurifère et cuprifère s’est révélée complexe. La pratique actuelle traite la saignée ou le débit total d’une solution de traitement du concentrateur pour récupérer le cuivre sous la forme de sulfure de cuivre (par sulfuration, acidification, recyclage et épaississement), ou pour récupérer le cyanure (par acidification, volatilisation et neutralisation). Le procédé présenté dans cet article utilise l’adsorption sur charbon actif de la solution de cyanure de cuivre et l’élution sélective du cuivre depuis le charbon pour concentrer le cuivre en un plus petit jet. Le cuivre contenu dans ce plus petit jet est précipité sous forme de cyanure de cuivre.INTRODUCTIONProcessing gold-copper ores by cyanidation has been a cost-control challenge since the cyanidation process was first used in 1889. Copper cyanide is stable only in the cuprous state, not the cupric. This factor results in the oxidation of a mole of cyanide per mole of nonchalcocite copper extracted. Each mole of copper extracted forms a cyanide complex with a minimum of 3 mol of cyanide. This cyanide-to-copper mole ratio is required to dissolve gold. The oxidation of cyanide and copper complexation with cyanide results in high cyanide consumption for copper-gold ores, which is a significant operating cost.One challenge in processing gold-copper ore is the cost of cyanide related to the extraction of copper. Processing 10,000 t/d of ore containing 1,000 mg/kg copper and 10% copper extraction yields 1,000 kg/d of copper. Currently, processes to remove copper from cyanide leach solution treat either the total flow of the barren or a bleed of the barren. The two processes used for copper-gold ores are sulfidization, acidification, recycling, and thickening (SART), which produces a copper sulfide product for sale; and acidification- volatilization-neutralization (AVR), which recovers the cyanide from a gas and produces a low–cyanide content solution. This low–cyanide content solution can be recycled to the process or might require additional treatment before being disposed from the operation."

Jan 1, 2017

By James A. Finch

"Developed countries are in the midst of re-structuring education in minerals-related disciplines as raw materials, once vital to wealth generation, contribute progressively less to the economy. The changing circumstances mean institutions must justify mineral processing by new criteria. After considering what a mineral processor needs to know the ways to deliver are considered. Taking twenty graduates per year to illustrate, one institute could justify this number as a program in a department or school (of whatever grouping of disciplines). A strong research component would make the package additionally attractive. Divide among four institutions and mineral processing is best served in a research centre with delivery taking advantage of multi-centre and distance learning opportunities.INTRODUCTIONThis is one of five plenary lectures at the Congress. I may have preferred a technical subject, as that is what occupies most of my thinking hours, but it is reasonable as an academic that this topic should come to one of us. The fact the topic has not been high on my agenda may provide one advantage: that I can suggest directions free of pre-conceived notions, just as when reviewing the background to a technical article the temptation to select in support of one?s interpretations is resisted. The trick will be to add something new.One reading of the title seems to query whether mineral processing education has a future. (I will refrain at this juncture from defining mineral processing and assume for now we share an understanding of the term.) The proximity of natural and human resources led to the Industrial Revolution and the interaction continues to stimulate and sustain industrial and economic development in many parts of the world. The search for raw materials has historically played a key role in opening frontier areas, with undersea and outer space next. The reason is obvious: raw materials along with food and energy underpin society. Thus mining will remain part of human activity along with the need to pass on the knowledge and skills.What happens over time is resource relocation. Raw materials become exhausted in one area to be replaced by sources elsewhere; the demand for some materials lessens while growing for others. Educational institutions can find themselves with the wrong geography or with staff focussing on the wrong subjects. When this happens the restructuring produces much discussion. This is where we are in parts of the world. Japan, Western Europe and the United States are the prominent examples (Dowd, 1998; Flemings and Suresh, 2001; McDivitt, 2002). Mineral processing is becoming a series of courses in related disciplines: resource engineering, environment engineering or materials engineering. The start of the transition is evident in Canada and Australia, perhaps earlier than expected given the contribution of raw materials to their economies. A common backdrop in the developed countries is social pressure to reduce the impact of the ?untidy? aspects of life, and that includes mining. (This is not new: in classical times the mine face was the preserve of slaves and convicts.) These values are exportable, potentially affecting recruitment into mining schools everywhere."

Jan 1, 2003

By J. Kemeny, J. Lyons-Baral

"Point cloud technology is now an indispensable tool in geological and geotechnical data collection, interpretation and analysis. Open pit and underground mines of all sizes are regularly collecting point cloud data as Laser Scanning (LiDAR) and Photogrammetry surveying devices have finally become affordable and the workflows fast and efficient. Past challenges of large data processing and manipulation are gone with recent technological advancements in computer hardware and software. These innovations reduce file sizes, ease rendering requirements and allow for the implementation of real-time 3D viewers and surface meshing tools. With its ability to remotely (safely), rapidly and accurately extract large quantities of georeferenced and 3D-oriented data, point cloud technology provides numerous applications to the geomechanical field. The list of uses is continuously growing, so this paper specifically focuses on digital outcrop modeling and digital terrain engineering. INTRODUCTION Point Clouds The high-resolution and increasing availability of point cloud technology is rapidly improving open pit and underground mines’ investigation, interpretation and characterization of site geology and rock mass properties (Kemeny et al., 2015; Lyons-Baral, 2012). LiDAR and photogrammetry are common remote sensing methods employed to measure the coordinates of surfaces in three dimensions (3D), providing the X, Y and Z locations, and typically the reflective intensity and/or the visible three-band color of each point (Figure 1). LiDAR uses either a time-of-flight or phase-shift measurement of a laser beam reflected off targeted surfaces and received back into the device. Photogrammetry generates point clouds by merging multiple overlapping photographs and uses stereographic plotting to define the locations of object points in 3-D space. These methods can be deployed from airplanes, unpiloted aerial systems (UAS or drones), tripods, land vehicles, and even in a mobile backpack shown in Figure 2. RADAR, Total Station-Prism and other remote sensing systems also offer very precise “point clouds”, but this paper does not address these due to their higher cost and lower versatility and mobility. Technology In the past few years point cloud acquisition device prices have dropped significantly, devices have become lighter, smaller and easier to operate, and processing and utilizing the data has also become faster and easier. Device size improvements include mobile backpacks (Figure 2) and handheld mobile LiDAR (CISRO, 2014), allowing mobile scanning in tight spaces both above and below ground or inside and outside of man-made structures. Airborne data acquisition options have expanded dramatically with the spread of UAS technology as seen in Figure 3 (Hexagon Geosystems, 2015). Once UAS usage regulations are sorted out, these versatile machines will be everywhere, offering high resolution coordinate scans, imagery and other remote sensing. While backpacks and handhelds allow access to tight quarters, UAS permit rapid data capture from narrow to broad areas with multiple perspectives reducing data “shadows.”"

Jan 1, 2016

By Charles Roeder, Amy Leland, Dawn E. Lehman

Concrete filled steel tubes (CFSTs) are composite members that are commonly used in many countries today. CFST components are used in the United States, but they are more common in Asia, in part because the connections used in Asia are quite labor intensive and there are not standard connections in the U.S. In addition, US design specifications are prepared by separate groups for structural steel and reinforced concrete structures and so composite systems that use CFST components are not overseen by a single group and as such there are several, conflicting design standards. In the US, steel tubes used for CFST are more slender (i.e., the diameter-to-thickness, D/t, ratio is larger) than some other countries, and labor practices (structural steel labor is different than reinforcing steel labor) also cause potential conflicts in construction. As a result, CFST has had some use in tall building construction in the US, but very limited use in bridge construction. A research program at the University of Washington has been in progress to address many of these issues with an eye towards universal design expressions, simpler, standardized connections and promotion of accelerated bridge construction (ABC). The research has resulted in recent changes to the American Association of State Highway Officials (AASHTO) bridge design specification as well as state departments of transportation (DOTs), which supports the increased use of CFST in bridge pile and drilled-shaft foundations. An experimental research study which investigate the flexural strength, shear strength and connections was conducted. These connections provide good performance under both seismic and gravity loads and address the concerns of US construction. These connections, their design rules and requirements, and their impact on composite behavior and system performance are discussed. These results permit rapid and economical construction of CFST bridge piers, piles and drilled shaft foundations. They encourage the use of more slender and economical tubes, while achieving the benefits of composite construction. INTRODUCTION Concrete filled steel tubes (CFSTs) are widely used for bridge and building construction in Asia, but the use of CFST in bridge construction is limited in the US. The historical use of structural steel and reinforced concrete in US bridge construction have resulted in more developed design expression for those construction methods, which has limited the use of CFST. Bridge construction in the US is inherently different than in Asia because of differences in codes, labor costs and construction practices. As a consequence, design and construction practices that are economical and practical in other countries may not be practical for US bridge construction.

Jan 1, 2019

By F. C. Canney

Geochemical prospecting seeks hidden mineral deposits by sampling for variations in the chemical composition of naturally occurring materials. Usually the samples are of soils and other products of weathering and erosion-surface materials extremely susceptible to contamination by human activities. Except when a survey is conducted well away from populated areas, contamination is an ever-present hazard. The program's success is particularly endangered when the contaminants are the elements sought; if these occur erratically throughout an area, spurious anomalies completely unrelated to mineralized areas can be formed. Evenly distributed contamination can be dangerous too, if it raises the background to such a level that true anomalies can no longer be easily detected. Suppose, for ex- ample, that in an area where the lead background is 20 parts per million the soil over a lead vein contains 1000 ppm of lead. Here the contrast would be 50 to 1, which is very satisfactory for geochemical surveying. Now if 1000 ppm of lead from some source were added evenly to the soil in this area, the contrast would be reduced to about 2 to 1, and the anomaly would no longer be readily detectable because a threshold of significance twice the value of the background is the minimum generally used for interpreting geochemical data.

Jan 2, 1959

Rio Tinto Iron Ore (RTIO) manages eleven mines in the Pilbara region, Western Australia. Three of these mines have previously or are currently mining black shale that contains varying amounts of pyrite. Several new deposits currently being evaluated and existing mines that may progress below water table in the future, will also encounter this waste material. The black shale presents not just an acid rock drainage risk but also a spontaneous combustion risk. This paper presents the black shale management strategy and provides an overview of the relevant activities undertaken by RTIO. The strategy can be divided into two components which firstly involve defining the risk and secondly involve managing the risk. The mineral waste management plan is used to identify specific mineral waste hazards by:geochemical characterisation of waste material,undertaking mine site specific risk assessments,characterising the receiving environment,identifying sulfidic boundaries in geological and mining models,quantifying the amount of sulfidic material in medium and long-term mine plans, anddesigning and sequencing black shale waste dumps. Once a mine exposes black shale the Spontaneous Combustion and Acid Rock Drainage management plan is used and the major activities are: regular site meetings with a representative from every group that works with black shale;compliance with safe working procedures for site specific and detailed activities;regular training;the use of specific explosives to prevent premature detonation;ongoing geochemical characterisation;acid water management, monitoring and analysis;regular internal and external auditing of procedures and practices; andclosure planning assessments and preparations (ie cover trials, geochemical void modelling, geochemical waste dump modelling). The success of this holistic strategy is evident by the awareness of personnel within the business, thorough understanding of the geochemistry and by undertaking proactive management of black shale during mining. The strategy and management plans adopted by Rio Tinto Iron Ore have activities that other mine sites with potentially acid forming material may like to consider implementing.

Jan 1, 2009