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By A. Eitzenberger

This paper describes a study of seismic records from the Kiirunavaara mine footwall which were interpreted in relation with numerical models developed outside the study. Seismic data was retrieved from a portion of the mine and filtered with respect to the ratio between energy carried by an event's P (primary) and S (secondary) waves (Es/Ep ratio), local magnitude, and active mining depth. The data was analysed using Es/Ep ratios and Gutenberg-Richter graphs to determine the event origin, mechanisms, and minimum magnitude cut-off. The magnitude completeness was identified by studying the b-value stability and b-value differentiation between origin sets. It was shown that, by separating seismic events into the origin components shear, complex, and tensile based on Es/Ep ratios, a representative value for the magnitude completeness can be identified for a catalogue with a convex cumulative log curve. The majority of the events were shown to be of shear-slip origin based on the recorded Es/Ep ratios, with pure tensile events constituting only about 10% of the recorded data. Spatial and temporal event location patterns were studied and compared with numerical modelling results. The comparison showed a correlation between shear-slip seismic events and volumes experiencing high differential stresses in the lower part of the footwall. In the upper part of the footwall the results did not reveal any clear correlation between observed damage in drifts and seismic event locations. The concentration of seismic events in the lower portion of the footwall is discussed in the context of rock mass displacements. The results indicate a possible connection between mine seismicity at depth and damage observations in the drifts in higher non-seismic areas by seismic softening and subsequent lateral expansion of the rock mass.

Jan 1, 2017

By Tucker G, Clark A, Young M. F, Johnston M

Mount Isa Mines has made a huge commitment to process control in milling. Yet in lead zinc we still failed to achieve a steady operation. Comparisons with manufacturing plants showed the key difference was failure to control plant inputs. Lead

Jan 1, 1998

By R. M. Gooding

This paper presents a short history of the production of mineral-energy fuels and energy from waterpower in the United States, with brief discussions of the utilization of each of the fuels and hydropower, and a look at fuels competition and interchangeability. Basic data, in figures and tables, are brought together in this publication for the production of coal in the United States from 1800 to 1960, for crude petroleum, natural gas liquids, and natural gas from 1859 to 1960, and for hydropower since 1900. Production for each segment of the fuels complex in the principal producing States from 1946 to 1960 is shown. Data are not included for consumption as such or for imports and exports.

Jan 1, 1963

By Matheus Sexto Alexandre Pereira

Controle e centralização de informações referentes ao processo industrial são imprescindíveis e considerando-se que na cadeia de suprimento o maior valor agregado costuma estar na produção, faz todo sentido investir em sistemas que possibilitem a otimização do fluxo, controle e qualidade do processo. O novo Sistema de Controle de Panelas (SIPAN) implantado na CSN permitiu monitorar em tempo real todo o ciclo operacional utilizando novas tecnologias de desenvolvimento de software web, além de melhorar o gerenciamento, comunicação com outros sistemas e rastreabilidade de todo o processo. O sistema implementado conseguiu melhorar a qualidade de informação para a equipe tornando mais rápida e assertiva a tomada de decisão.

Jul 30, 2018

By Christopher Andreae

Years before iron and steel works were established at Sydney, several thriving although short-lived iron works operated in Nova Scotia. These furnaces reflected the general nineteenth-century North American experience with iron works. At the beginning of the century, small furnaces struggled to supply local needs. Charcoal was the principal fuel and water powered most furnace equipment. By the end of the century, a few huge primary iron and steel works dominated production for Nova Scotia and the rest of Canada. Two sites achieved prominence in the nineteenthcentury Nova Scotia iron industry: Londonderry and Ferrona (Fig. 1). Londonderry, the larger and longerlasting of the two sites, is today a small village on the south flank of the Cobequid Mountains, about 30 km west of Truro. Prior to the establishment of an iron works in 1849, no community existed. At the peak of operation in the 1880s, however, over 2600 people were located there. The second site, Ferrona, today is a mere crossroads on the map, about 10 km south of New Glasgow. Following the construction of a blast furnace there in 1892, a small village grew up around the furnace. But once the furnace was blown out in 1904, the population gradually drifted away.

Jan 1, 1999

By N. A. Zeigler

GRaphitization phenomena occurring in solid cast iron have principally been studied from the angle of the reactions taking place during annealing of white castings in the manufacturing of malleable iron. The selected bibliography at the end of this paper presents the high spots of the published information in this field. Graph-itization of gray iron upon reheating has received much less attention, primarily because only on rare occasions is this material subjected to any kind of industrial heat-treating. Moreovcr, articles made from gray iron are seldom used commercially at temperatures when any graphitization can take place. When used in such conditions, it is assumed that the articles can be replaced at frequent intervals, which can be afforded because of the low cost of gray iron. However, there is at least one commercial process in which articles made from gray iron, during their manufacturing processing, are subjectcd to rather high temperatures; that is, manufacturing of cast-iron enamelware, which is glazed at about 1600° to 1700°F. (870' to 930°C.) From practical experience, it has been found that one of the convenient and economical compositions of gray iron suitable for enameling is, in round figures, as follows: Si, 2.50 per cent; Mn, 0.35; S, 0.07; P, 0.80; T.C., 3.35; C.C., 0.70. Since this iron usually is cast into thin-walled sections, the percentage of com- bined carbon in it is relatively high. Upon heating in the enameling furnaces, this combined carbon graphitizes, which causes permanent dimensional changes of the articles. Obviously, from practical considerations, it is desirable to maintain these dimensional changes as constant as possible. In the course of experimentation with this iron, two series of experimental heats were prepared in which the manganese to sulphur ratio of the standard cupola metal was offset by ladle additions of: (I) progressively larger amounts of sulphur, and (2) progressively larger amounts of manganese. Each one of these ladle charges was cast into experimental plates 8 by 4 in. and about 5/16 in. thick. All told, 13 ladle charges were thus treated. All of them are listed in Table I, together with their chemical analyses. It may be noted that the manganese to sulphur ratio in these samples ranges between 1.2 and 30.2. Every one of these compositions was subjected to thermal allalysis, using an automatic, self-recording differential dila-tometer. The specimens used in this instrument are 50 mm. long and 4 mm. in diameter. During the dilatometer cycle they are kept under a vacuum of about 3 microns. Each one of them was subjected to a thermal cycle by heating it to I830°F. (1000°C.) in 3 hr. and cooling to room temperaturc in 5 hr. Figs. I, 2 and 3 present three automatically recorded dilatometer curves for irons: Serial No. I (normal composition), Serial No. 6 (high sulphur), and Serial No. 13 (high manganese). All three of these figures are

Jan 1, 1945

By A. Buncombe

In March 1984, two years' work by senior metallurgical personnel from the six major mining groups culminated in the formation of the Mine Metallurgical Managers' Association of South Africa. This Association has joined a group of specialist Associations operating within the South African mining industry whose aims are to uphold the standards and promote the interests of their various professions.

Jan 1, 1987

By I. Silin, H. Wotruba, A. Liono, I. Volobayev, Y. Rubinstein, D. Gürsel

Old, abandoned or in situ processed and storaged tailings can be a potential source of remained valuable metals and minerals. By reprocessing of tailings, it is possible not only to achieve economical profit from recovery of valuable metals, but also to reduce environmental damage caused by tailings such as generation of acid mine drainage from sulfide minerals, mobilization of heavy metals, soils and groundwater contamination. In addition, storage facilities can be successfully redesigned with modern geotechnical requirements and monitoring to avoid a dam collapse of abandoned tailings. In this case study, the processing of low grade abandoned tailings was investigated. Copper (0.15%), cobalt (0.032%) and gold (0.35 ppm) were determined as main valuable and recoverable metals. Cobalt occurs as cobaltite and cobaltiferrous pyrite, while chalcopyrite represents copper. The fine fraction of tailings below 32 μm is enriched with cobalt and copper. Preliminary test-works with initial tailings sample were aimed to recover copper, cobalt and gold. The previously tested magnetic and gravity separation could not recover the metals in a pre-concentration step. Flotation tests of the tailings sample had shown a suitability for flotation without previous regrinding of the tailings. The valuable minerals are first proposed to be recovered by collective flotation, followed by a selective circuit with production of a low grade copper concentrate and a cobalt bearing pyrite concentrate. Based on various tested collectors, amounts of sulfidisation agents and activators, a suitable reagents regime was determined and used for up-scaling by locked cycled test. Keywords: reprocessing, tailings, copper, cobalt, gold, flotation, cobaltite, cobaltiferrous pyrite

Jan 1, 2020

By T. Klemetti

Moisture deterioration of clay-rich roof rocks causes high numbers of roof falls in coal mines in humid summer months. Rocks with high moisture content are generally weaker and can further deteriorate when subjected to wetting and drying cycles. As a result, it is important to evaluate the moisture-sensitivity of roof rock prior to mining. The National Institute for Occupational Safety and Health (NIOSH) has evaluated three moisture-sensitivity index tests on roof rocks from 23 U.S. coal mines. The three tests were the University of Kentucky Weatherability test (Weatherability test), the Consol Energy Water Sensitivity test (Water Sensitivity test), and the NIOSH Immersion test (Immersion test). Of these three tests, the Weatherability and Water Sensitivity tests are more reliable in classifying the moisture-sensitivity of roof rocks. Disclaimer: The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.

Jan 1, 2009

By Wallace N. Thomas

The present interest in large diameter grinding mills and the rapidly rising cost of the drive in proportion to the cost of the mill establishes a need to explore the drive system in detail. The drive for a seven to eight thousand horsepower mill will cost from 1350 thousand to $600 thousand which represents nearly half the total cost of the mill package, and requires as much building space as the mill proper. Some of the drive components require a longer time to manufacture and the installation time and costs are equal to those for the mill. It is apparent that the drive has become a dominant factor in the overall mill design consideration. A new plant requires a tremendous investment in both time and money. With the high degree of competition in the mining industry, low capital cost is an exceedingly important factor in the development of a project. It is just as important, however, to insure that the equipment is going to perform satisfactorily for the anticipated life of the project without adding unplanned operating, maintenance and replacement costs. This is the position in which the engineer or designer usually finds himself and is really one of his primary functions -- establishing a realistic compromise between cost and performance.

Jan 1, 1969

By Gary N. Weinrich

Large surface mining projects in sparsely populated regions of the West have the potential to create disruptions in an area's social and economic character with potential effects on man that can far outweigh the physical and ecological effects on man's environment. The data and analyses involved in addressing the socioeconomic issues are additional to those traditionally associated with surface coal mining, such as those concerning land reclamation and water quality. Appropriate socioeconomic studies in conjunction with mine-planning can identify the potential problem areas in order that project measures can be taken to maximize the beneficial impacts and minimize the adverse effects of surface coal mining. The information required to conduct such socioeconomic analyses, available data sources, and the applicable analyses are described. Overall impacts of some proposed Western surface mines are summarized and potential mitigating steps discussed.

Jan 1, 1975

By P wade

This is the first Presidential Address given to the Nottinghamshire Branch of The Institution following the merger of the Nottinghamshire and North Derbyshire Branch of The Institution of Mining Engineers (IMinE) and the Midland Branch of The Institution of Mining Electrical and Mining Mechanical Engineers (IMEMME). I intend to review the formation of the individual institutions as well as what has been achieved by mining related institutions over the years and finally I intend to look to our future.

Jan 11, 1996

By G. Van Esbroeck, M. Van Weyenbergh

The copper mines of the Katanga region in the Belgian Congo lie along the same mineralized belt as those of Northern Rhodesia. There are two distinct types of deposits in that belt, the dolomitic and the quartzitic. In the dolomitic type the metallic minerals are found in a dolomitic limestone country rock. Through oxidation and enrichment, large deposits of high-grade oxidized copper ores were formed, some of which are being worked by the Union Minière du Haut Katanga. Such deposits are all in Katanga. The quartzitic deposits are found in Katanga and Northern Rhodesia. Here the primary mineralization occurred in sandstones and quartzites, in horizons stratigraphically lower than the dolomites. These rocks are not favorable to secondary enrichment and the oxidized zone is poorer than the sulphide zone, which alone contains the ore. There are also in Katanga a few ore-bearing veins. One of them is being worked in the Prince Leopold mine at Kipushi. Prince Leopold Mine The Kipushi ore body fills a fault vein and invades the wall rocks more or less extensively by metasomatic replacement. The vein strikes north-northeast and south-southwest and dips to the west. The variable dip averages 60' to a depth of 300 ft., and more uniformly 80' below 400 ft. In the upper section the average width is 200 ft. and below the width is about 150 ft. The length of the ore body is 2300 feet. The eastern side of the vein—the footwall—is dolomitic and contains irregular masses of ore sometimes extending 100 ft. or more from the main

Jan 1, 1940

By M. Van Weyenbergh, G. Van Esbroeck

The copper mines of the Katanga region in the Belgian Congo lie along the same mineralized belt as those of Northern Rhodesia. There are two distinct types of deposits in that belt, the dolomitic and the quartzitic. In the dolomitic type the metallic minerals are found in a dolomitic limestone country rock. Through oxidation and enrichment, large deposits of high-grade oxidized copper ores were formed, some of which are being worked by the Union Minière du Haut Katanga. Such deposits are all in Katanga. The quartzitic deposits are found in Katanga and Northern Rhodesia. Here the primary mineralization occurred in sandstones and quartzites, in horizons stratigraphically lower than the dolomites. These rocks are not favorable to secondary enrichment and the oxidized zone is poorer than the sulphide zone, which alone contains the ore. There are also in Katanga a few ore-bearing veins. One of them is being worked in the Prince Leopold mine at Kipushi. Prince Leopold Mine The Kipushi ore body fills a fault vein and invades the wall rocks more or less extensively by metasomatic replacement. The vein strikes north-northeast and south-southwest and dips to the west. The variable dip averages 60' to a depth of 300 ft., and more uniformly 80' below 400 ft. In the upper section the average width is 200 ft. and below the width is about 150 ft. The length of the ore body is 2300 feet. The eastern side of the vein—the footwall—is dolomitic and contains irregular masses of ore sometimes extending 100 ft. or more from the main

Jan 1, 1940

By Rick Deschamps, Brian Barkauskas, Aled Hughes, Abigail Stein

In central Washington, six miles south of the small town of Vantage, the flow of the Columbia River is harnessed by the Wanapum Dam which is part of the Priest Rapids Hydroelectric Project owned and operated by Grant County Public Utility District (GCPUD). Extending more than 8,300-feet from bank to bank, the dam includes left and right earth embankments, left and right concrete gravity sections and a 10-unit powerhouse. Adjacent to the right embankment is a concrete gravity spillway featuring radial gates measuring 50-feet-wide and nearly 70-feet-high. In the early 1960’s when Wanapum Dam was built, these seven-story spillway gates were the highest in the world. In late February 2014, 50-years into its service life, during a routine maintenance inspection, observant workers noticed a slight misalignment in the roadway deck curbs and handrails located on top of the spillway. Further survey and inspection efforts uncovered a 65-foot-long by two- inch-wide crack that spanned the full length of Monolith 4. On discovering the extent of the damage, GCPUD initiated immediate drawdown of the reservoir to relieve pressure on the spillway monoliths. Wanapum Reservoir and the areas directly downstream of the dam were immediately closed, boat ramps and inlets were left completely dry, campsites were closed and boating activity was banned on the lake until further investigations and remedial procedures were in place and completed. An extensive root cause analysis ultimately led to the conclusion that errors in the initial design calculations and late changes to the final spillway design led to a condition that generated tensile stresses in the concrete at the upstream face, which over a period of 50-years resulted in the formation of a crack along a horizontal lift joint located about 85-feet below normal pool elevation. Further analysis showed that, although visible distress was found at Monolith 4, there was nothing preventing this issue from happening at other locations along the dam spillway. Although no visible cracking was found in the other monoliths, repair procedures for Monolith 4 would have to be replicated at the remaining monoliths.

Jan 1, 2018

By B Banerjee, N Kumar, S Parihar

Rampura Agucha Pb-Zn Mine (RAM) is located about 200 km to the south-west of Jaipur in the state of Rajasthan, India. Open pit mining operations commenced in 1988 and continued to 2018. RAM open pit footprint is the largest in India with length of 2000 m, width 1500 m and depth of 400 m. Development of an underground mine under the operating pit commenced in 2013, through trial mining longhole open stoping with cemented backfill was established as a preferred mining method. Nine years in operations underground mine has reached the production capacity of 4.5 MT, which represent more than 70 per cent of the ore volume mined by the pit. RAM is currently the world second largest underground Pb-Zn mine.

Nov 29, 2022

By Claude Bazin

The Quebec province in Canada is a major producer of aluminium through electrolysis of alumina. The alumina that feeds the electrolysis cells is mainly imported from foreign countries, where it is extracted from bauxite. Other alumina sources, such as clays, have sometimes been considered as potential substitutes for bauxite. There is a large clay deposit in the area of Murdochville in Quebec, with sulfuric acid and electricity available nearby the orebody, as well as sea port facilities leading to the major aluminium plants in Quebec. These are favorable factors to assess the economics of an industrial plant to produce alumina from clays. This paper reviews some of the processes considered for the extraction of alumina from clays and presents results of the initial work carried out on the clay available from Murdochville.

May 1, 2001

By Oliver Bowles

ROCK is no doubt the most abundant of all material things because the planet on which we live is made of it. All animal and vegetable organisms and the multitude of natural and manufactured products that occupy a comparatively insignificant film on the outer surface of the planet are derived from rock. Processes of Nature acting for untold centuries have transformed rock into soil, making possible the development of vegetable and annual life; and rocks have supplied the numerous raw materials, metallic and nonmetallic, wherewith the innumerable appurtenances of a complex civilization have been fabricated. As time goes on we live with increasing speed and with enlarged desires. Time and space are shortened by man's ingenuity, and products for human use must be manufactured with greater and greater celerity. It was inevitable that Nature's slow processes of rock alteration should fail to keep pace with human demands and that the variety of natural products should fall far short of the requirements of an industrial age. Man therefore supplemented these processes by attacking rock in its native bed amid using it to supply needs not otherwise satisfied.

Jan 1, 1934

By Just GD, Gillies ADS

There is an increasing need for reliable and comparable coal resource data and it is necessary to standardize the traditional classification procedures by quantifying the three basic evaluation criteria of economic feasibility, geologic assurance and recovery. For well documented deposits, geostatistical methods can consider- ably improve classification quality. A geostatistically based algorithm for classifying coal resources within the current Queensland and New South Wales codes has been developed. Application of the method in classifying resources from a number of seams exhibiting different structural characteristics is assessed. The method is found to give classification results which closely reflect the error associated with an estimate of resource quantities based on current sampling densi- ties. It requires a careful geostatistical analysis with emphasis on geological awareness. Resource category restrictions must be arbi- trarily assigned and remain constant for all deposits being compared. Engineering judgement is needed and interpretation may be required with isolated and peripheral blocks.

Jan 1, 1987

By R. N. Chakravorty

It is well established that coal can react with oxygen in air at ambient temperature and as a result heat is produced. If the heat is not fully dissipated the temperature of the coal mass will increase, thereby enhancing the rate of oxidation with a greater production of heat. If this phenomena continues, the coal mass can ignite under favourable heat accumulation conditions. A number of mine fires are caused each year due to this phenomena, commonly known as spontaneous combustion. The early detection of spontaneous combustion is of prime importance to mining engineers since any fire which could be detected at an early stage may save the mine from considerable damage and subsequent loss of production. Obviously, there is no single general criteria by which one can assess whether the under- ground mining of a coal seam will result in liability to spontaneous combustion. This has made it imperative to develop systems for the early detection of heating and to follow its development. In recent years considerable advances have been made in the design and development of methods for the early detection of spontaneous combustion. The Mining Research Laboratories (CANMET) is presently investigating the problem of spontaneous combustion in coal mines with Kaiser Resources Ltd. at their hydraulic mine at Sparwood, B.C. on a co-operative basis, and some of the work was described earlier in the Canadian Institute of Mining & Metallurgy Bulletin (1,Z). This paper summarizes and updates the work done by CANMET on the detection of spontaneous combustion in coal mines.

Jan 1, 1980