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By D. H. Desy

This research was undertaken to establish the lncendivity of aluminum alloys against rusty steel under frictional impact conditions at typical coal mine fan speeds, to determine any differences in incendivity among various aluminum alloys, and to Investigate less incendive materials as substitutes for aluminum alloys. With a specially designed apparatus, three aluminum casting alloys and three constructional steels were tested for incendivity in frictional impact against rusted steel in flammable methane-air mixtures. Although varying in degree, all aluminum alloys investigated exhibited a high ignition probability under the test conditions; none of the steel specimens tested caused any ignitions under the same conditions.

Jan 1, 1973

By J. S. WARWICK, E. J. Browning

Ignitions continue to occur underground, sometimes leading to major explosions. There has been considerable effort in the UK, and more widely in the European Community, to formulate the best ventilation practices and other means of minimising these incidents. Practices and procedures to prevent ignitions are discussed in the light of the risks from current mining methods.

Jan 1, 1993

Editor's note: Biographical information about Ihor Kunasz, president, Newmont Uzbekistan, can be found in the February 1998 issue of ME, page 94 and in the May 1996 issue, page 92. Your personal assessment of the minerals business. Gosh! When I think about what has happened to the minerals industry over the past 27 years that I have been a member of SME! There have been fundamental structural changes in the industry. And I think that SME has been quite successful in coping with these changes as well. There has been a reorientation in how the minerals industry does business. It used to be called rationalization. Today we call it reengineering. In addition, the minerals industry has become more complex and more global. Shareholders have become more vocal and demanding in the management of the business, asking for protection of their shareholders' value. In the 1980s, a fundamental change was precipitated by a merger and acquisition fever in all industries, including the minerals industry. Raiders such as T. Boone Pickens put enormous demands on companies that, in turn, had to spend substantial management time to fend off the raiders. This resulted in a major restructuring of the mining houses. Today, for example, Anaconda, Kennecott and Amax are only historical names.

Jan 1, 1998

By A. F. Robertson

FOR several years, the rock-burst question has been given serious consideration by the operating staff at Wright-Hargreaves mine and, as a result of observations and experiences, several different methods of mining have been developed which are now in use in various parts of the mine. These are described in the following pages. It should be emphasized, how-ever, that these methods, and the views expressed in this paper, are based solely on conditions at Wright-Hargreaves mine. Such conditions may or may not be similar to those obtaining in other mines in the Kirkland Lake area, where ore occurrences, veins, wall-rock, faulting, intrusives, etc., may be entirely different. Size and shape of ore-bodies, composition of the ore-bodies and their surrounding rocks, locations of intrusives and sedimentary rocks, and direction, dip, and strength of faults, all introduce problems that are peculiar to each individual mine. Ground failure' in coal and metal mines is not at all unusual. A variety of systems of mining have been developed to delay movement of large or small blocks of ground, or, in some instances, to take advantage of the fact that ground movement, due to mining operations, is unavoidable. Ground failure may be either slow collapse or it may take place with explosive violence. It is principally with the latter condition that we are concerned in the mines of the Kirkland Lake district.

Jan 1, 1939

By W. T. Robson

ONE of the problems encountered in any mine is the effect of increasing pressure manifested by increasing depth. Although the depth at which excessive pressure assumes serious proportion, and the manner in which it appears in underground workings, are influenced by a variety of factors, nevertheless the difficulty is present in all mines and its gravity increases with increasing depth. In the Kirkland Lake camp, as far back as seven years ago, mining had proceeded to depths sufficient to result in the formation of pressure great enough to cause violent disruption of masses of rock. It is proposed in this paper to deal with the effect of pressure caused by mining as observed at Lake Shore Mines, and to describe some of the methods which have been adopted to counteract it. There are many contributing factors in a study of the problem, and results vary widely in individual mines and in different localities. One feature common to all, however, is that there is ground subsidence, evidenced either by a gradual settling accompanied by crushing and shearing of the ore and wall-rocks, or the disruption of the ground surrounding the periphery of an excavation may take place suddenly, attended by more or less violent shattering of the rocks. Such violent failure of a mass of rock has been designated by the term rock-burst. The history of rock-bursts extends over a great number of years. They have occurred in some form or other in practically ali places where mining operations, at all but very shallow depths, have been carried out. Since the theoretical aspects of the subject have been dealt 'with at great length by capable and experienced writers (1), the present paper will give only a brief résumé of the theories propounded by those engaged in deep mining operations in various parts of the world.

Jan 1, 1940

By Marvin B. Thompson

"The depositional model for major Illinois Basin coalbeds is well documented and defined on a regional scale. The model was a driving force during past exploration for lower sulfur and thicker coal deposits. The most attractive coal reserves were known to lie along the flanks of contemporaneous sandstone filled stream channels and were overlain by thick silty gray shale roof. At various distances away from the channels, the depositional model transitioned to black shale I limestone roof, sulfur content of the coal bed increased, and the coal bed often thinned. Understanding the character of roof rock types associated with this depositional model is essential to predicting ground control factors on both a regional scale, and on resolving roof control problems at the mine-site. Additionally, horizontal stress and overburden depth are significant factors that impact roof rock quality and ground control in Illinois Basin mines.Determining the character of several rock types, and defining the primary horizontal stress direction were crucial to a recent successful project at New Future Mine, located in southern Illinois. An inclined slope was constructed from the Illinois No. 5 Coalbed up to the Illinois No. 6 Coalbed through strata that ranged from extremely weak ""stackrock"" and a weak underclay unit, to a massive sandstone unit. Engineering geology, operations management, and Jennmar technical services personnel teamedup to select and install roof support for each strata transition. The project was completed with no injuries and no roof falls.INTRODUCTIONAbundant published information concerning coal deposition, geographic distribution, quantity, quality, and mining conditions exists for Illinois Basin coal reserves. The State of Illinois, through its State Geological Survey (ISGS), has provided decades of research, record keeping, and service to the coal industry. Other excellent sources of Illinois Basin coal information include the Indiana Geologiq1l Survey and the Kentucky Geological Survey. Past research by the U.S. Bureau of Mines (USBM) supplemented the work by the geological surveys, especially in the area of horizontal stress and mining hazards. The National Institute for Occupational Safety and Health (NIOSH) continues to produce publications focused on roof control issues common to many coal basins, including the Illinois Basin. Many of the illustrations in this paper originated in ISGS and USBM publications."

Jan 1, 2010

By J. C. Heter

The P.W. Gillibrand Company has been processing and stockpiling a suite of heavy minerals at its Soledad Canyon Mine as co-products with construction aggregates since 1984. The heavy minerals are composed of ilmenite, magnetitie, apatite and zircon. The source of the heavy minerals is the Precambrian San Gabriel Anorthosite Complex of the western San Gabriel Mountains. The valuable minerals are readily amenable to standard ore dressing techniques, such as, gravity, magnetic, flotation and electrostatic separation with good recovery and product quality. More than 20,000 short tons of coarse ilmenite were sold in 1990 to the export market for titanium pigment production.

Jan 1, 1992

By I. D. Hagar

WHEN the history of American business during these momentous war years is written, an absorbing chapter will be devoted to the Maclntyre Development, in northern New York. It will tell of a timely mining project, deep in the wilds of the Adirondacks, blasted into being by Axis torpedoes. It will recount the labors of 1500 engineers and workmen, miles from a highway, rail line, or power source, who built a huge enterprise in a few short months' time. And it will list these major contributions to the war effort: more than a quarter million tons per year of ilmenite, source of titanium dioxide-man's most opaque white pigment-to be used in paints for warships, tanks, guns, planes and the plants that build them; as a co-product, over 500,000 tons each year of magnetite-an important type of iron ore- to help feed the cavernous maw of America's wartime steel industry.

Jan 1, 1942

By J P. van Dyk

A new crude ilmenite beneficiation process was recently proposed that allowed for the preparation of a smelter grade ilmenite from ilmenite with elevated chromium content. Magnetising roasting was not utilised in the process. As part of this circuit an ilmenite low susceptible reject stream was produced that had a low magnetic susceptibility. In this article a magnetising roasting process was investigated to beneficiate this material. Tests were conducted on material produced by pilot scale simulations on a typical South African East Coast heavy mineral reserve. The results obtained were compared to those published in literature for crude ilmenite. The small-scale experiments were used to define approximate operational limits for the oxidising roasting of a low susceptible ilmenite low susceptible reject stream, although industrial roasting conditions may differ significantly from those obtained in laboratory units. In a next phase these results will be confirmed on pilot plant scale.

Jan 1, 2001

By G. Folmo

Allis Mineral Systems' GRATE-CAR agglomeration/induration/reduction process is currently being operated to process ilmenite at Tinfos Titan & Iron KS in Tyssedal, Norway. In this process, balled ilmenite concentrate is fed to a traveling grate where pellets are dried and preheated, using fully oxidized kiln exhaust gas. Hot preheated, semi-indurated pellets are fed directly to a ported kiln where reduction of the ilmenite's iron oxide fraction occurs in the presence of lump coal. The reduced pellet sand coal char are discharged from the kiln to an indirect rotary drum cooler. Cooled pellets and char are screened and magnetically separated prior to their further processing in a downstream smelting operation. The pellets are melted and the titanium dioxide and iron are separated. Operation commenced in late 1986.

Jan 1, 1992

By J. H. Zietsman

Ilmenite smelting furnaces must be operated with a freeze lining of frozen slag to protect sidewall refractories from chemical attack by liquid slag. The process has two main control objectives: Firstly the slag TiO2 content must be controlled according to specification, and secondly a safe freeze lining thickness must be maintained. This text only concerns itself with the second objective. Freeze lining thickness cannot be measured directly due to conditions inside the furnace. It is therefore inferred from signals of thermocouples installed into the furnace sidewall. These signals are used as the 'controlled variables' in the freeze lining thickness control loop. The dynamic characteristics of these signals are the focus of this text. During this study a model of the process was constructed to study interactions between the slag bath and the freeze lining. This model was used to conduct simulation-type experiments to study the influence of various parameters (temperature, slag composition, ilmenite feed rate, reductant feed rate, power input, etc.) on the slag bath, freeze lining, metal bath, furnace wall and other parts of the process. In the case of the furnace wall, the modelling results were first plotted in the form of time-dependent isotherms. The dynamic thermal behavior of the furnace wall became evident from these results. To illustrate the dynamics of sidewall thermocouple signals, the results were also plotted as time lags between events occurring in the slag bath, and the time when a thermocouple registered a temperature change. The events studied included sudden changes in slag bath state (composition and temperature), changes in operating setpoints (ilmenite feed rate, reductant feed rate, power input), and operational errors (complete loss of reductant or of all feed). All of the result sets showed significant lags between occurrences in the slag bath and temperature changes in the refractory wall. The delays are such that it appears impractical to rely on sidewall thermocouple signals for warning of impending damage to the refractory wall, or for purposes of actively controlling freeze lining thickness. Some measures are suggested to improve the usefulness of these signals during furnace operation.

Jan 1, 2005

By Milton Manrique

The thermal decomposition of ilmenite concentrates in a non-transferred arc; thermal plasma flow reactor was investigated. The plasma torch was operated using argon-helium and argon-nitrogen mixtures as plasma gases. The effect of power, feed rate and particle size was studied. Products were characterized by XRD, SEM, TEM and ICP techniques. Free energy minimization plots were used to predict the thermodynamic behavior of the system under different operating conditions. The results of this investigation showed a significant segregation process where titanium-rich products are collected in the reactor, while iron-rich products are collected in the quenching box and filter. The average size of the product is in the sub- micron range. Titanium nitride was formed and condensed in the reactor zone when using an argon-nitrogen mixture as the plasma gas.

Jan 1, 1998

By T. Lux, M. Hanel, Degel, A. Filzwieser, R., H. Joubert

It is the increasing demand for an economic and cost saving operation mode that requires effective cooling in order to achieve low refractory wear and good furnace lifetime, which is making cooling technology an important aspect of furnace operation. In addition, the requirements for safety are getting more and more into focus. However, the use of water—today’s standard cooling medium—has major drawbacks as it can cause problems both during furnace start up and operation, namely hydration problems, corrosion, and explosion. Not to forget the severe risks for the operators as well as economical damage in case of a malfunctioning water cooling system. With this new and patented cooling technology ILTEC and the ionic liquid IL-B2001 as the cooling medium, it is possible to realise a water-free cooling solution and therefore the door is wide open to rethink existing and conventional cooling solutions. Furthermore, there is also the chance to recover heat from the process in a more efficient way. However, since the technology is novel and unique there are a lot of concerns and doubts regarding safety for plant operators and employees. The paper is intended to cover both: highlighting the enormous potential of the technology but also to eliminate concerns mainly caused by rumour and unawareness. INTRODUCTION All of us are aware of the risks when water is used as a coolant and placed in the vicinity of the liquid metal phase. Unsuitable design solutions or wrong operation modes of the furnaces or failures of refractories can cause a direct contact of water with liquid metal. The consequences can lead to equipment failures, vessel destruction but even worse to injuries and even fatalities. Over the past decades, countless incidences were reported. Fatal accidents caused by water coming into contact with liquid metal happen every year (Oterdoom, 2014; Filzwieser, Konetschnik, Filzwieser, Wallnerm & Preiss, 2014). With the novel ionic liquid cooling technology virtually all negative effects of a water cooled system regarding safety are eliminated and even additional benefits can be provided (Voermann, Ham, Merry, Veenstra, & Hutchinson, 1999;Verscheure, Kyllo, Filzwieser, Blanpain & Wollants 2006; Wallner, Filzwieser & Kleicker 2006). The fact that no explosion occurs when IL-B2001 gets in contact with molten metal results in a revolutionary solution for the metallurgical industry in terms of safety—new safety standards can be achieved.

Jan 1, 2019

By R. Bruce Thorndycraft

Heap leaching should not be chosen for development of a property solely on the basis of paper studies. Management should be made to understand where the risks are in heap leaching, and management should be alerted to the variability of costs in heap leaching, many of which are based upon company philosophy. These concepts are complex, but easily illustrated with guided tours of existing heap leach facilities.

Jan 1, 1998

Over the years, numerous studies have been conducted to characterize the floatability of coal pyrite. Unfortunately, many of the results obtained using isolated samples of coal pyrite are not directly applicable to actual coal flotation systems where liberation and entrainment may be the major factors affecting pyrite rejection. In this paper, the association of pyrite with other coal constituents is investigated, and the data are presented for feed and product streams obtained from release analysis tests. Release analysis is used to minimize the effects of entrainment. Particle distributions for each stream are presented as functions of size and composition in order to discern the behavior of free and composite particles.

Jan 1, 1992

By William Petrul

Image analysis studies were performed on mill products from laboratory flotation tests of the Zn-Pb ore from the Faro deposit in Yukon, Canada, to determine mineral liberations at specific grinds and to predict recoveries at optimum flotation conditions. The minimum and optimum grinds for liberating sphalerite and galena were predicted from size analysis data for the minerals in large ore pieces, and determined by image analysis studies of the mill products. The determined optimum grinds are about 2 Tyler mesh sizes larger than predicted because sane of the fine grained sphalerite and galena occurs in interstices between coarser grained pyrite and is liberated when the pyrite grains are broken apart. Materials balance calculations were performed on the analyzed values for the liberated and unliberated sphalerite and galenaa to determine their distributions in the mill products. The laboratory flotation tests recovered 74% of the sphalerite and 83% of the galena in Zn and Pb concentrates respectively. The mineral evaluation study indicates that the optimum recovery for sphalerite and galena are 85 and 83% respectively. The company is currently recovering 80% 'of the sphalerite and 82% of the galena.

Jan 1, 1989

By William Petruk

Image analysis studies were performed on mill products from pilot-plant and laboratory tests that had been conducted to determine the effect of grinding media on the selective flotation of two zinc-lead-copper ores. It was found that, when the ores had been ground to the same degree of fineness with flint pebbles, ceramic pebbles or ore fragments (autogenous grinding) as with steel balls, there generally was increased sphalerite, chalcopyrite and galena liberation in the flotation feeds, depending on the textures of the minerals. The increased sphalerite liberation fully accounted for the improved zinc recoveries that were obtained when steel balls were replaced by either pebbles or ore fragments. The increased chalcopyrite and galena liberation accounted for part of the changed technical efficiency of concentration, but other factors, probably changes in oxidation and reduction of iron and in consumption of oxygen, also contributed.

Jan 1, 1977

By William Petruk

The development of automatic image analysers brought the application of image analysis into process mineralogy because the analysers can measure parameters more easily, quickly and accurately than by manual grain counting techniques, and can also collect data unobtainable by manual grain counting. Data from ore specimens and mill products are used to predict and to define the behaviour of minerals during processing. The analyses are generally performed on the basis of either surface areas or linear intercepts of grains in polished or thin sections, and the data are computer processed to give mineral quantities, liberations, size distributions, and characteristics of middling particles. For analysis, the minerals must be detectable and discriminatable from each other. An image editor is usually used when minerals are not easily discriminated. In addition BSE-8EM photographs have been used where the silicate minerals could not be discriminated from the mounting media. Methods of analysis, typical results, and their applications are discussed.

Jan 1, 1982

By D. J. Reddish, B. N. Whittaker, G. X. Sun

An image analysis technique has been used in the assessment of subsurface fracture levels in the context of water inflow into longwall mine workings. The technique was used to analyse results from physical modelling which are represented by black and white photographs taken directly from the model tests. Binary images of fracture patterns are obtained by scanning the photographs with an image analyser coupled to a video camera. The images are manipulated by a C program which allows them to be processed in vertical and horizontal directions and filtered to differentiate quantitatively between vertical and horizontal fracture intensities. The fracture density distributions provide a valuable database for further numerical and statistical analysis. This allows assessment in terms of water inflow into the excavation. A comprehensive image analysis was undertaken on several extraction models. Results indicate that extraction thickness has a significant effect on the fracture pattern and the fracture density distributions. The results can be used to adapt model findings to situations with a range of extraction thicknesses. The technique has allowed improvement in image enhancement and in the interpretation of model results. In particular, a qualitative comparison between different models is possible.

Jan 12, 1992

While the United States and the rest of the world struggles with record-setting oil prices Canadian oil sands producers are ramping up production to meet demand for oil while also fighting against a host of negative images. In recent months, the price of oil has skyrocketed. Most of that oil comes from Saudi Arabia. In Alberta, Canada there are unconventional oil reserves that rival those in Saudi Arabia in the vast Canadian oil sands, sometimes called the tar sands. Proponents of the oil sands say that Alberta?s oil sands can be a secure source of oil and energy for the United States for many years to come. With new mining and drilling projects, the industry has said that it could quadruple its production to nearly 4 million bbl/day by 2020. Time magazine once called the oil sands, ?Canada?s greatest buried treasure that could satisfy the world?s demand for petroleum for the next century.? So why hasn?t the United States embraced this close, politically secure source of energy? Because, getting usable fuel from the oil sands can be a dirty business, say opponents. The oil sands are a combination of clay, sand, water and bitumen. It is a heavy, black, thick oil. Oil sands can be mined and processed to extract the oil-rich bitumen, which is then refined into oil. The bitumen cannot be pumped from the ground in its natural state. Instead, tar sand deposits are mined, usually using strip mining or openpit techniques, or the oil is extracted by underground heating with additional upgrading. These methods require a huge amount of energy and water and produce a large amount of carbon emissions. Environmental groups that have long spoken out against the oil sands projects got some political backing in the United States in June when a group of mayors from large U.S. cities spoke out against the oil sands, as did presumptive Democratic candidate for U.S. president Barack Obama?s senior energy advisor. During a convention of large-city mayors in Miami, FL, Alberta?s oil sands were singled out in a nonbinding resolution calling for national guidelines to track the lifecycle impact of different types of fossil fuels. The resolution urges cities not to use unconventional sources of energy with a large carbon footprint, such as liquid coal and oil shale and oil sands.

Jan 1, 2008