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By N. W. Bliss

"Bauxite has been the almost universal ore of aluminum for about 100 years, with most of the world's reserves oc¬curring in the developing countries. As a result of fiscal and political activities prompted in part by the energy crisis, the formation of the IBA combined with increasing freight and labour costs, these reserves are no longer as competitive or as secure as they once were. This has given fresh impetus to the development of processes for alumina production that utilize raw material other than bauxite. Canada has no bauxite and it is prudent to look for alter¬native raw materials within our own boundaries suitable for one of these processes.Of the three igneous rocks that have been used as a source of alumina, only anorthosite is considered as a potential source in Canada. The Al content would be extracted by a sinter process, which currently requires a raw material with a. minimum of 28% Al2O2. Thus, about 4 tons of anorthosite and 10 to 12 tons of limestone are needed to produce one ton of alumina. There are two petrologically distinct types of anorthosite, one containing the plagioclase andesine-labradorite and around 26% Al2O3, and the other containing upwards of 30% Al2O3, in by¬townite-anorthite; for our purposes they may be con¬sidered as low- and high-alumina anorthosite respectively. The high-alumina anorthosites are somewhat rare; the low-alumina anorthosites are much more common, partic¬ularly in Eastern Canada. Geologically speaking, there is no shortage of anorthosite in Canada. The reserves are im¬mense, although their low Al2O3 content coupled with con¬siderations of location, access and proximity to limestone could be constraints to their development. Fly ash from coal-fired thermal power stations and nepheline syenite can also be used in a sinter process, but neither is likely to be utilized in Canada in the immediate future.The H+ process utilizes an acid attack to leach Al from a raw material with at least 20% Al2O3. One of the best raw materials is kaolinite-bearing clay; not only is it high in Al, but most of it can be extracted. With the possible exception of the Whitemud clay in Saskatchewan, Canada is apparently deficient in clays with sufficient reserves to support an alumina plant utilizing the H+ process. Low-alumina clays with illite and montmorillonite may also prove to be a suitable raw material if advantageously sited with respect to industrial centers. The average shale con¬tains only 15% Al2O33, much of which may be contained in minerals, such as feldspar, not amenable to acid leaching. If shale is used as a source of alumina, it will be because it contains some other valuable commodity, such as oil or uranium, the extraction of which leaves the spent shale upgraded in extractable Al2O3 and lowers the over-all costs to a point where it is economic, Thus, rejects from coal washing plants are most commonly considered as a source of alumina; they are already mined, are available in large and ever increasing amounts, and may contain significant amounts of combustible material which upgrades the Al2O3, content of the resulting ash. Coal rejects from existing and developing coalfields in Alberta and British Columbia are a possible source of raw material, but present data indicate they may contain insufficient Al2O3."

Jan 1, 1976

By E. J. Karges

The use of pulverized coal for generating power and performing industrial processes has made an important contribution to our industrial economy during the past half century. Actually, the burning of coal in powdered form is a subject that has held the attention of engineers for a century or longer. Its widespread use, however, is comparatively recent, As early as 1866 patents were granted to Messrs. Whelpley and Storer for a method of feeding pulverized coal into a furnace as an auxiliary to the grate fuel. In the many tests made during the subsequent years with various kinds of apparatus, the experimenters were handicapped in not getting the coal fine enough to obtain complete combustion and to prevent excessive formation of slag.

Jan 1, 1965

By V. E. Dawson

Brake testing of large mining trucks was initiated in British. Columbia in 1969 following an accident involving the failure of the service brakes of a l00-ton electric-drive truck. Some selected results of the 1976 brake test program are presented and discussed ?in this paper . The tests were conducted on end- dump trucks having load capacities ranging from 85 to 235 tons. All tests were made with the vehicles fully loaded operating on downhill grades varying from 8 to 10 %. Stopping distances were measured from initial speeds varying between 10 and 39 mph. The results are adequate, in most cases, to determine the "ultimate" capabilities of the service brakes of varying models and sizes of haulage trucks operating in British Columbia mines.

Jan 1, 1977

By A. D. Walters

"IntroductionScreens are used in coal preparation plants for four basic functions, namely:I. Scalping off large size run-of-mine coal for initial size reduction;2. Sizing of coal treatment in different process streams;3. Removal of magnetite (dense medium) from clean coal and refuse;4. Dewatering.Canadian coal preparation plants use screens extensively in the above functions. Even plants where no beneficiation takes place, screening and crushing are carried out in the size reduction process.Description of Process UnitsThe type of screen used in coal preparation plants generally falls into the following categories:Fixed Screens and Grizzlies (for large coal)Often a simple rugged construction, either set horizontally above a bin or inclined with the coal flow.Fixed Sieves (for fine coal)They are used for dewatering and/ or size separation of slurried coal or discard. The sieve bend, the Vor-Siv, the Wilmot riffle and the cross flow screen fall into this category. The most commonly used in coal preparation plants is the sieve bend, Figure 1. Coal slurry is fed tangentially onto a fixed curve wedge wire screen deck. The solids are separated at a predetermined particle size, delivering a partially dewatered overproduct and a dilute underflow. The coal slurry is initially delivered to the sieve bend via a feed box. A series of baffles spreads the feed evenly across the width of the deck. The slurry drops from the last baffle, passes through the feed spout and is fed tangentially to the screen. It is important that the feed should contact the surface immediately at the front end of the sieve bend. It is possible to lose as much as 250Jo of screening area with a poorly fitted screen box.The full stream of coal slurry flowing over the sieve bend decreases in depth, in increments of approximately •;4 the slot width each time it passes a slot. Sieve bends make a size separation at 112 to 2h the slot width. This feature virtually eliminates blinding of the screen surface. Slot sizes are normally quoted in millimetres, available standard slot sizes are from 2 mm to 0.125 mm. The sieve bend is also widely used in coal preparation for preliminary dewatering."

Jan 1, 1989

Since its organization, in July, 1917, the War Minerals Committee of the Institute, of which William Y. Westervelt is chairman, has been studying important phases of the mineral industry and its relation to winning the war. From this has come a realization of the imperative need for more definite coordination than is possible without direction by some governmental agency. No privately controlled industry can have the detailed knowledge of war needs or the control of all its supplies and markets necessary to effect the adjustment of its activities for war purposes. Inevitable shortages of certain essential minerals confront us unless immediate steps are taken to stimulate and develop. the mining

Jan 2, 1918

By R. A. Hevia

Florida Power and Light is the fifth largest investor-owned electric utility in the country. It has a service territory that covers 35 counties, or 28,000 square miles, 2.5 million customers, and serves 5.6 million people. The total installed capacity is 13,470 MW, generated by four nuclear units, 36 oil and/or gas fired units, and 48 gas turbine units. Traditionally, FPL has been an oil-based utility. In 1979, this dependency on oil became obvious when 42 million barrels of oil were burned during the year. At that time, it was also projected that, based on the current estimates of customer growth and available generation capacity through 1990, FPL's residual fuel oil consumption would increase from the 1979 level of 42 million barrels (6.7 million m3) per year to approximately 55 million barrels (8.7 million m3) per year by the mid-1990's. Concern over this was further aggravated by the fact that it was difficult to estimate both the price and quantity of fuel oil that would be available over the next decade since changes in the world market, decisions by oil producers and refiners, and international political developments would all affect the availability of oil. Also, at that time, the price of residual fuel oil had increased drastically, and there was no reason to think that these prices would soon stabilize. Thus, oil back-out became a primary objective of FPL and since then, FPL has been actively investigating ways to decrease fuel oil consumption.

Jan 1, 1985

By E. H. Skinner

An abandoned mine shaft near Omar, in Logan County, W, was permanently sealed through a cooperative agreement between the West Virginia Department of Commerce, Labor, and Environmental Resources, Division of Environmental Protection, and the US. Bureau of Mines (USBM), Abandoned Mine Lands (AML) Program. An engineered shaft seal design was developed and demonstrated that featured lightweight concrete as a key material component at a wet density of about 45 lb/ft3. A reinforced concrete cap designed for 5 psi live load was placed over the shaft seal. Applicable new concrete technologies relating to a 100-yr design life were utilized to assure future integrity of the shaft seal. Waterproofing methods were included in the shaft seal design to provide protection from ambient moisture and corrosive mine waters and to increase the long-term durability of the shaft seal. All construction methods used in the field trial are fully adaptable for the mine-reclamation contractor, The USBM research objectives were to develop a broad generic design that will be widely applicable to other adit-sealing and shaft-sealing problems throughout the mining industry.

Jan 1, 2010

By T. McKeon, G. Luttrell

Spiral separators are commonly used to upgrade sand-sized particles in both the coal and mineral processing industries. Many plants utilize multiple stages of cleaning and/or scavenging spirals to improve recovery and/or final product grade. Field studies suggest, however, that the layout of industrial spiral circuits is often less than optimal. This oversight can usually be attributed to a failure by plant designers to consider fundamental process engineering rules that govern the layout of complex separation circuits. This article reviews some of these important rules as specifically applied to multistage spiral circuit design. Two industrial case studies, one involving the upgrading of heavy mineral sands and a second involving the cleaning of fine coal, are presented to illustrate the impact of good design protocols on spiral circuit performance.

Jan 1, 2007

By J. V. W. REYNDERS

IN THE remarks which I am about to make concern¬ing the safety work of the Bureau of Mines, I want first of all to disengage myself from a disposition, which is frequently in evidence, to give spectacular emphasis to the hazards of mining operations. It is of the' utmost importance to the industrial welfare of our country that the enormous annual requirement of fuel be produced and be made available in our economic activities, with a minimum of distress and hardship. The safety of coal mining is a condition with which. we are all concerned in a fundamental way. And yet we should not rush to accept hastily conceived notions that laxity among employers in respect to safety measures exists to any outstanding degree. In fact in a large number of instances, the precautionary efforts of min¬ing companies, directed to the elimination of accidents are beyond all criticism, albeit the industry suffers in reputation from the carelessness of, its less effi¬cient constituents. The Bureau of Mines has been a leading influence in disseminating the doctrines of safety, in securing the cooperation of the miners themselves, and in stirring up ' the laggards, both among the employers and the employed. It is much to the interest of well-conducted mine operations that the industry, as a whole, observe safety regulations to the utmost.

Jan 1, 1925

By A. Doroudgar, H. Noferesti

Unstable rock failure or rock bursting is one of the most dangerous problems in deep hard rock mines. This type of failure, that occurs uncontrollably, is associated with a significant release of strain energy from the surrounding rock. In this study, the numerical simulation of unstable rock failure was carried out using the three-dimensional explicit Lagranian finite-volume finite difference method to identify the onset and location of unstable failure events in the model. On this basis, a numerical simulation of mine pillars with width-to-height ratios of 0.5, 2 and 3 was performed. A criterion was developed, based on the calculation of the elastic strain energy, to determine the prone areas for the initiation of rockburst in the models. The results of this study showed that, in softer loading systems, due to large amounts of stored elastic strain energy, an unstable equilibrium is established, which leads to the rapid transfer of strain energy to the rock in the form of violent failure. It was also found that the unstable failure starts at the corners and free surface of the model. The new criterion developed in this study may help predict the occurrence of rockbursts in slender pillars and the design of pillars to control human and financial losses caused by this phenomenon.

Nov 27, 2024

Paper presented at the Mining Institute of Scotland's annual general meeting held in Glasgow, 8th April 1916. Although there is nothing novel or difficult about the sinking described, circular shafts are not numerous in Scotland so the details connected with such a sinking may be of interest. The shaft was sunk at Dykehead Colliery, Larkhall, which has been worked for over 50 years from the upper seams. It became necessary to sink another shaft to serve as a replacement downcast, by which the output might be maintained and some of the lower seams won. As the sandy clays regularly caused bulging into the rectangular shaft and sinking of the surrounding ground it was decided to make the new shaft circular and to enclose its mouth in a foundation-block of concrete resting on the solid clay. Details are given of the sinking, brick seating and lining, kettle strike, water-rings and doorhead lintels as well as the permanent fittings, winding gear and the cages themselves

Dec 1, 1916

By Oscar Concha

El presente texto describe la exploración, geología, controles estructurales, mineralización y los tipos de alteración hidrotermal del yacimiento minero Cuajone, situado al sur de la Cordillera Occidental de los Andes y en el flanco Andino de Moquegua. En 1937, se inicia su exploración a través de una campaña exploratorla de la empresa Cerro de Pasco, donde se determina la zona como un proyecto potencial de cobre porfirítico de baja ley. Posteriormente en 1942, se inicia la primera campaña de perforación diamantina exploratoria y en 1969, se inicia la etapa de construcción y desbroce de material para preparar la mina. De otro lado, se ha desarrollado un modelo de la evolución del yacimiento desde las rocas preminerales del Grupo Toquepala, de las cuales la andesita basáltica fue una gran receptora de la mineralización de cobre originada por la intrusión de un primer pulso de latita porfirítica.

Apr 26, 1999

By John Metz, D. E. Macdonell

The Falconbridge ore body, on the southeastern periphery of the Sudbury Basin, is definitely associated with a strong shear zone along the norite greenstone contact, in contrast to the "offset" ore bodies sometimes found in this district. To all practical intent and purpose, the dip is vertical. The ore varies in width from a few inches up to 90 ft., the average width being 15 ft. The present zone of mining operations is 6000 ft. long, 85 per cent of which develops commercial ore. The ground on the whole, and especially in the narrower widths, gives rise to reasonably strong self-supporting backs in most places, but the walls, because of strong post ore faulting on both norite and greenstone contacts, tend to be weak, and, at times, slough to a considerable extent. Obviously. then, with vertical dips, strong backs and weak sloughing walls, flat-back cut-and-fill methods are applicable to the Falconbridge ore body, and at present about 70 per cent of the stoping production is obtained in this way. The general method is described in the following pages. In actual practice, there are continual variations, as the mine staff feels that only in that way can new and better methods be developed. Source of Fill The overburden at the property consists of glacial sands and gravels, varying in depth from 00 at the outcrops, which are few and far between, to 150 ft. This condition makes for high initial cost of shaft sinking, always entailing spiling and concrete, but this extra expense is more than compensated for by the fact that the overburden is the source of very cheap fill.

Jan 1, 1946

By Rob Morrison, Andrew Scott

"Long before a modern mine commences operations it has already become a wealth of information. After start up, it can generate enormous quantities of data - especially with semi-automated data acquisition by instrumented mine equipment.However, much of this data is of limited use for evaluation of (potential) performance unless it links in some way to the site business model.An underlying reason for this waste of data is that the different cultures, financial, technical, community, environmental, etc, not only have many areas of interest but also have very different conceptual models by which they evaluate performance.It is too ambitious to attempt to bring all of these cultures together - in a single step.However, the success of the Mine to Mill - project has demonstrated that substantial operational value can be added by using a more integrated approach to comminution. The next logical step is to integrate measurement and then to track performance from ore body model to saleable product and waste disposal. From resource to product also represents a path from very sparse, highly variable data to much more detailed measurement and more representative sampling.However, in both cases the data collected is strongly focused on the technical requirements - not on the business model.This paper considers how to define at least some of the key decision points in terms of some case studies.Performance data from many areas might be used to derive simple models which can then be used for forecasting and optimisation of planning."

Jan 1, 2003

By S. Esfahani, M. Barati, Y. Kauwachi

"Heat recovery from slag has gained attention due to its high potential in lowering energy intensity of metal extraction processes. A direct method to recover the thermal energy of slag is to use countercurrent air flow that extracts the heat from falling droplets. Often, the solidified slag is aimed to be used as a substitute for Portland cement, thus high cooling rates are required to form an amorphous slag with sufficiently strong hydaulicity. Rapid cooling however involves using large gas flow rates that in turn lower the thermal efficiency of the process. This article presents a mathematical model that was developed to determine the optimum conditions in the heat recovery process and to investigate the effect of the air flow and granule diameter on the cooling rate of the droplets as well as the thermal efficiency of the heat recovery system. INTRODUCTIONMetallurgical slags are the largest by-product of high temperature materials refining and extraction processes. The total amount of metallurgical slag produced in the year 2008 has been estimated at up to 422 million tonnes containing up to 222 TWh/y (Barati and Esfahani, 2011) of thermal energy. Over the past four decades attempts have been made to recover this substantial amount of energy as heat, electricity, or fuel, while none of the proposed method has been commercialized yet.During slow cooling the slag tends to crystallize the constituents (CaO, SiO2, Al2O3, etc.) into a hard, heavy solid. In the past, over 90% (Bengt, 1983) of the molten waste was discharged onto heaps and allowed to cool slowly, then crushed and used in road construction or land filling or as coarse aggregate for concrete. However, later it was found if cooled rapidly, the slag can be used as a substitute for Portland cement. As a result, processes such as wet granulation were created in which molten slag is fragmented with water, forming amorphous (glassy) phases. Despite its effectiveness in producing a suitable material, heat would not be recovered through this process. Thus, dry granulation was introduced in 1930’s and was developed further in 1970 – 1980’s."

Jan 1, 2012

Taknar polymetal (Cu-Zn-Au-Ag-Pb) deposit and concentration flotation plant are located in the northeast of Iran. The flotation feed contains Chalcopyrite, sphalerite and pyrite with 4, 4 and 8 percent respectively. Cu and Zn contents are 1.26 and 3.5 present. Pyrite decreases the quality of base metal concentrates and increases the amount of sulfur compounds produced in the base metal extraction processes. Therefore, depression of pyrite is essential in the concentration of base metal sulfides by flotation. For flotation tests, 4 mixed collector systems, MIBC (20g/t), lime and tow depression systems (sodium cyanide (60g/t)-zinc sulphate and dextrin (300g/t)-zinc sulphate) were used as collector, frother, pH regulator and pyrite-sphalerite depressants in the chalcopyrite flotation stage, respectively, and SIPX, MIBC, lime and copper sulphate (as activator) were used in sphalerite flotation from first stage tailings. The results have shown that, sodium cyanide is a suitable depressant for pyrite and sphalerite in the first stage of flotation. Compared to dextrin as depressant, chalcopyrite recovery was decreased approximately 1.83%. In addition, when sodium cyanide was used as pyrite depressant, copper sulphate consumption raised approximately 90 g/t for activation of sphalerite. From Environment and HSE points of view, dextrin is natural, biodegradable, and non-toxic while cyanide is very high toxic. Keywords: sequential flotation, Cu-Zn massive sulphide, pyrite depressant, dextrin, cyanide

Sep 1, 2012

By Richard F. Flanagan, Robert H. Marshall

The Republic of Singapore’s Public Utilities Board is implementing the Deep Tunnel Sewerage System Project. The project’s deep tunnel component, 48 km of deep, large diameter sewer tunnels has been successfully completed (the works are in the defects liability period). Six International Design/Build tunnel contracts utilized eight Earth Pressure Balance TBMs ranging up to 7.23 m in diameter to deal with varied ground types ranging from deep soft clays to fresh granite. Numerous access/workshafts were constructed and using various support systems. This paper provides an assessment/overview of the tunnel contracts, tunnel excavation methods and equipment, and the shaft systems. Suggested enhancements to similar future projects are provided.

Jan 1, 2007

By Angela Binder, Mareike Schubert, Yichen Jiang, Sandra Nowosad, Oliver Langefeld

GermanyINTRODUCTIONThe mining industry is currently characterized by various factors such as environmental impact, resource scarcity, social responsibility and geopolitical uncertainty. The production of minerals required to meet the demand for renewable energy is expected to increase by 500 % by 2050, particularly for critical minerals such as graphite, lithium and cobalt 1. Easily accessible deposits are often depleted, meaning that deeper and more complex deposits need to be developed. Furthermore, investors’ value systems have shifted towards more sustainable practices. Alternative approaches to solving this problem are therefore currently being developed, such as the Modular Mining Systems concept for scalable and adaptable mining projects 2. Many mining companies have also taken important steps to become more sustainable, implementing measures such as proactive closure strategies, restoration programs and the development of renewable energy projects. In the European Union, laws such as the Critical Raw Materials Act and the Net Zero Industry Act support the mining industry 3,4. They see it as important for the energy transition and promote more sustainable ways of working in the industry Particularly negative environmental impacts such as land degradation, scarcity of local water resources, water pollution and greenhouse gas emissions are ingrained in society’s memory. Despite these efforts, the public image has not yet changed. To change this perception, the industry must strive to better communicate its sustainable practices and the steps it is taking towards a more responsible and sustainable future, promote transparency and build trust.Digitalization, automation and electrification are driving the digital transformation in mining. However, their implementation can lead to higher capital expenditure, limiting their adoption across the industry. Furthermore, implementing new technologies can be a daunting task for any organization. Change management comes into play when introducing such disruptive technologies. It involves preparing an organization for change, potential resistance and establishing effective communication. This helps to ensure that the implementation is successful and the benefits of the new technology are maximized. Digital transformation requires well-trained, young mining, electrical, mechatronic and software engineers with a deep understanding of information systems. Unfortunately, the industry faces the enormous challenge of attracting this younger generation, who have little interest in the extraction of raw materials. The need for action is compounded by an aging active workforce heading into retirement and the forecast of increasing demand for critical minerals.In this challenging environment, the concept of Blue Mining with its constant further developments represents a promising approach. This implies a shift from a linear to a sustainably oriented circular economy. For the mining industry, this specifically means the introduction of innovative technologies, the increased recovery of materials from waste and the consistent questioning and application of circular principles along the entire life cycle of a mine. Such a change can not only reduce the environmental impact, but also contribute to economic resilience and increased social acceptance of mining.

Feb 1, 2025

By L. R. Fisher

The purpose of this investigation was twofold: (1) To devise a rapid method for determining quantitatively the porphyrin-carboxylic acid content of a particular crude-oil porphyrin aggregate, and (2) to isolate porphyrins in the crystalline state from crude-oil porphyrin aggregates. The first purpose was accomplished by applying adsorption chromatography. In fulfillment of the second aim three different crystalline porphyries were isolated by methods which involved both adsorption chromatography and fractionation of benzene solutions with hydrochloric acid of varying strength. The three porphyrins had etio, rhodo-, and phyllo-type absorption spectra, respectively. INTRODUCTION Many samples of petroleum have, as interesting minor constituents, chemical compounds known as metalloporphyrins. Their presence in crude oil and other bituminous materials was first discovered by Treibs a quarter century ago. Much experimental work has been done on metalloporphyrins because of their importance to the petroleum industry. They have a deleterious effect on refining catalysts. The ash resulting from the burning of heavy fuel oil is very reactive, We to the presence of metallic constituents, particularly vanadium. In oil-fired gas turbines, the ash may build up on the blades, causing imbalance of the rotors and, in addition, severe corrosion. In industrial boilers, the ash residue is responsible for severe damage to boiler tubes and to the refractory brickwork (15).4 Through study of the chemical constitution of the various metalloporphyrins found in petroleum, much can be learned concerning the origin, migration, and history of crude oils.

Jan 1, 1961

By R. J. Leary

The Bureau of Mines experimental blast furnace was blown with oxygen-enriched blast in combination with natural gas injected at the tuyeres. The air blast was augmented with oxygen to form an enriched blast containing 24,8 pct oxygen, and tests were run at natural gas injection rates of 4.5, 6.0, and 8.3 pct of the air blast. Similar enrichment to 26.8 pct oxygen was tested at natural gas rates of 7.2, 9.1, and 11,0 pct of the air blast. At intermediate proportions of natural gas to oxygen, (1) the fuel rate and the replacement ratio of coke by natural gas were unaffected by oxygen injections and (2) the productivity increased about 4 pct for each I pct oxygen added to the blast. The higher proportions of natural gas to oxygen were less efficient; in return for a lower coke rate, the fuel rate increased and productivity declined. A deficiency in reducing gas imposed a limit upon lower than normal proportions of natural gas to oxygen. Beyond this limit the formation of reducing gas was insufficient to support the rate of metal production. When this condition was encountered, the coke rate requirement for specification iron was abnormally high and production fell off badly. Adiabatic flame temperature is discussed as a means for proportioning oxygen and natural gas additions.

Jan 1, 1967