Search Documents

By Paul R. Terry

This paper presents a brief picture of the quality of coal produced in Eastern Canada for use in thermal generating stations. It describes, in particular, the characteristics of coals burned in six power plants -two in New Brunswick and four in Nova Scotia. Each station is dis-cussed in turn, and comments are made on the coals used therein with regards to origin and physical and chemical properties affecting station operation. A table of coal data shows, at a glance, the wide variation in the quality of coals received by these stations from producers in New Brunswick and Nova Scotia. "The promotion of improved coal quality for thermal generation can benefit our national economy." T HIS is the opening statement in a paper which was presented by Mr. D. A. Pirttinen at the Coal Division's Toronto meeting in April, 1960. In bringing the power engineer's viewpoint to the coal producers' attention, Mr. Pirttinen made a survey of utility steam plants operating in Canada, and the results of this survey formed the basis for his paper, which he titled: "Generating Station Coal Quality.

Jan 1, 1965

By J. E. House, J. L. Drobnick, R. R. Swanson, D. W. Agers

The paper describes an improved process for the recovery, purification, and concentration of copper values from acidic dump leach liquors. The process employs a new liquid ion exchange material (LIX® 64 reagent) capable of separating copper values from iron and other impurities common to dump leach liquors in the typical pH range of 1.4-3.0. Properties and performance of the reagent are discussed. Design scale-up information for both pilot plants and commercial installations, including preliminary economics, are presented. Economic considerations include the production of electrolytic copper from the purified copper aqueous concentrate. INTRODUCTION Since the commercial acceptance of the liquid ion exchange process in the mineral processing industry, it has been predicted that a wide selection of chemical reagents to efficiently and economically separate many metals in solution under a wide range of conditions would be commercially available. Several years ago, General Mills began a basic research and development program to determine if it were possible to develop a reagent to extract economically metallic ion from existing process streams. Progress toward reaching this objective was reported in late 1963, when development of quantities of LIX -63 reagent, a highly selective reagent for the extraction of copper, was introduced. The properties of this reagent are described in a previous paper.' The development work with this reagent indicated that perhaps the largest potential application for a copper extractant, the treatment of acidic dump leach liquors, would not be economically possible with LIX-63 because of limitations of the reagent to extract copper below a pH of 3.0. The relatively small pH adjustment required with LIX-63 would result in a significant processing cost and the undesirable precipitation of ferric hydroxide from the liquor. This pointed to the need for another copper extractant which would extract copper from dump leach liquors without pH adjustment. General Mills was successful in synthesizing a molecule which does not have the pH limitation of the LIX-63, yet possesses the selectivity-solubility properties required of a metallic extractant. The resulting LIX-64 reagent broadens the pH range from which copper can be effectively extracted and separated from other metallic impurities. Of special significance is the fact that the reagent, LIX-64 was developed by combining the technical requirements of a specific problem in hydro-metallurgy with theoretical organic and physical chemical principles.

Jan 1, 1967

By P Ring, B Cooper, C Carr, G Laing

The Nova Ni-Cu-Co Operation, located in the Fraser Range of Western Australia, commenced commercial production in July 2017 only five years after discovery. Owned by Independence Group NL (IGO), the operation has successfully ramped up over an accelerated schedule and currently deploying leading technologies. This paper begins with a description of the Nova Operation, and its journey to achieve full production in such a short time frame. It includes discussions on development and production design, selection of fixed plant infrastructure, and the features challenges of running a low-pressure primary ventilation circuit. The paper also discusses key technologies that have improved overall safety for the underground workforce, and improved operational efficiencies. Investigations continue into the implementation of further technological applications for safety and productivity enhancements. This paper also discusses the findings from a study into transitioning from a diesel to an all-electric underground mining fleet, based on a review of Nova if it were to be developed today with the current EV offerings. The study indicates compelling savings will be available to future mines when considering development design, project schedule, capital outlay and operational savings, and the ‘next Nova’ is expected to be all electric.

Mar 15, 2021

By Axel Preusse

Underground coal mining can cause seismic events. There is currently no way to predict such phenomena reliably, in particular stronger events. That is why, according to the current state of the art, empirical methods are employed in this field. Some assessment criteria, which relate to the geological and mining situation and either stimulate or rather help to avoid seismic events, are presented in this paper. These criteria are examined for a practical mining situation in Germany, with a view to estimate possible seismic events.

Jan 1, 2009

By Raja V. Rarnani, Robert L. Frantz

More than 100 scientists from diverse professional backgrounds have contributed their expertise to the Dust Center as investigators. Approximately 50 researchers served as principal investigators, with responsibility for directing the work on Center projects, from experimental design and implementation in mines and in laboratories to coordination of efforts within the research infrastructure of the Center. The professional biographies which follow demonstrate the breadth and depth of research capabilities brought to the Center by its principal investigators.

Jan 1, 1995

Study to develop a new and more cost effective equipment system, incorporating a winch-pulled dozer blade, for leveling spoil and performing reclamation of area strip mines.

Jan 1, 1975

NATURE OF ORETHE Edna May ore consists mainly of clean quartz of a moderately hard and tough nature. The gold content is "free" and fairly coarse, so that a large percentage is recovered by amalgamation. The ore is practically free from metallic minerals.GENERAL OUTLINE OF PLANT AND TREATMENTThe ore, received from underground in trucks, is broken by a jaw breaker, then stamp-milled, follow~d by partial filie-grinding in pans. Mercury is used both in the mill boxes and pans. The pulp, on leaving the pans, passes over amalgamating tables and is then elevated by tailings pulp to cone classifiers and separated into a sand and slime product, each product receiving a separate cyanide treatment-sand by leaching in vats and slime by agitation and decantation in a "Trent" plant. Gold solutions from both sand and slime are precipitated together by zinc shavings in the usual type of precipitation boxes. Accumulated slime is trucked from the dam to a vortex mixer and from this point receives with the cement slime the same treatment.ORE BREAKING AND TRANSPORTThe ore is trucked from the brace of the shaft along an overhead line to the breaker station. Hence it is, by means of a "kick-up" dumped upon a grizzly, set with 2-in. spaces, the oversize being broken by a 15 x '9 Fraser and Chalmer jaw...

Jan 1, 1919

By C. Sawmliana, P. Pal Roy

Near-field blast vibration response of restrained pipelines either buried or exposed was studied during rock excavations at sensitive locations for Stage-II (4x500 MW) commissioning work in a super thermal powerplant of the National Thermal Power Corporation Ltd. (NTPC) of India. The existing running plant of capacity 1000 MW has many important installations including pipelines of varying diameters. These pipelines were very close to the blasting locations (mostly within 12m). Blast optimization and consequent monitoring of vibrations were carried out simultaneously for more than 250 experimental blasts conducted by the authors. This paper emphasized, particularly, on the safety of pipelines and their responses due to repeated blasting impacts. A few guidelines supported by theoretical derivations are provided for futuristic research.

Jan 1, 2001

The Bureau of Mines, through its Minerals Availability Program (MAP), investigates the mineral supply potential of the United States and market economy countries (MEC's) for a number of minerals considered essential to the U.S. industrial base. Major activities include identification of important mines and mineral deposits, estimation of their mineral resources and production costs, and availability and sensitivity analyses. Products include data print-outs of geological and engineering information, discounted- cash-flow rate of return (DCFROR) analyses of individual mining operations, commodity availability appraisals, and analytic services to Government agencies. These products are used in assessing the mineral supply position of the United States: in setting priorities for research aimed at reducing production costs and minimizing adverse environ- mental impacts and regulatory compliance costs of mining and mineral processing operations; and in formulating and evaluating Government policies that affect minerals. Bureau MAP data and analyses have been provided to the executive and legislative branches to aid in consideration of trade, tax, and stockpile policy issues. A study of the economic potential of selected seabed mineral resources supports the regulatory responsibilities of the Department of the Interior in the U.S. Exclusive Economic Zone. Analytic studies of mineral project viability, industry competitiveness, and import dependencies were also undertaken for, or in cooperation with, U.S. and foreign government agencies, industry and trade organizations, and international lending institutions.

Jan 1, 1987

The phosphorus content of the banded iron formation (BIF) and of the associated iron ore deposits in the north west of Western Australia is known to vary widely, a fact which has considerable econ~mic significance. Trendall and Blockley (1970) have described the variety of textural appearances of apatite in the Hamersley Group BlF, and suggest that apatite may account for the entire phosphorus content of the unaltered BIF.A preliminary investigation using an M.A.C. electron microprobe analyser has shown that, at least in some iron ores and in partially enriched BIF and associated shales, the phosphorus occurrence is more complicated than this. A suite of samples was examined from one location which covered the entire Dales Gorge Member and some adjoining macrobands in the Mt. McRae shale, together with samples selected for their high phosphorus content, degree of ore enrichment, and position relative to the enrichment zone. Calcium apatite was not observed in any sample of ore from this sequence, despite its ubiquitous occurrence in the BIF. Silicate mineralogy in the enriched regions also differs from that in the BIF, but this change has not yet been studied in detail.The phosphorus content of goethite in one orebody is often high and appears to be in solid solution in the goethite structure. It shows little or no variability on a micro-scale within a grain, except where theremay be a zoned enrichment near boundaries and solution channels. There is also a limited solubility of phosphorus in hematite (the maximum observed by the author is 0·1 per cent P); but where the hematite is martitic (after magnetite) its phosphorus content is always low or zero. In some bands, martitic hematite has been hydrated to goethite, and this also has a very low phosphorus content. Phosphorus was not found in the silica or silicates in the ore, and even when iron enrichment is just beginning, a limited suite of samples from the BIF suggests that the phosphorus content of the chert microbands is almost entirely in the microscopic goethite nuclei (after riebeckite) scattered throughout the chert. The ability of goethite and hematite to accept phosphorus...

Jan 1, 1973

By Chen Lin

Tectonic stress is an important parameter for understanding the dynamics of underground engineering and for the exploitation of coalbed methane. Multiple-period structural features usually have complex spatial relationships in tectonic superposition areas, which provides evidence for identification of the sequence of the tectonic stress period. Conjugated joints and slickensides are used to reconstruct the tectonic stress of the No. 8 Mine in Pingdingshan. Based on the geological unit division and field measurements, data on hundreds of joints and slickensides are collected from 33 stations. The tectonic stress results indicated by the conjugated joints show that there are mainly four directions of tectonic stress: NEE-SWW, NW-SE, NE-SW, and NNESSW. The tectonic stress results of the slickensides indicate that there are mainly four directions of tectonic stress: NNE-SSW, NNW-SSE, NEE-SWW, and NW-SE. According to the systematic analysis of the joints and slickensides, this paper separates the superposed joint and slickenside sets and identifies the tectonic stress periods with their abutting relationships. Three tectonic stress periods are determined and the sequence of the tectonic stress periods is NE-SW, NW-SE, and NEE-SWW. The results are consistent with other tectonic stress measurements for both the region and the locality.

By Chen Lin

Tectonic stress is an important parameter for understanding the dynamics of underground engineering and for the exploitation of coalbed methane. Multiple-period structural features usually have complex spatial relationships in tectonic superposition areas, which provides evidence for identification of the sequence of the tectonic stress period. Conjugated joints and slickensides are used to reconstruct the tectonic stress of the No. 8 Mine in Pingdingshan. Based on the geological unit division and field measurements, data on hundreds of joints and slickensides are collected from 33 stations. The tectonic stress results indicated by the conjugated joints show that there are mainly four directions of tectonic stress: NEE-SWW, NW-SE, NE-SW, and NNESSW. The tectonic stress results of the slickensides indicate that there are mainly four directions of tectonic stress: NNE-SSW, NNW-SSE, NEE-SWW, and NW-SE. According to the systematic analysis of the joints and slickensides, this paper separates the superposed joint and slickenside sets and identifies the tectonic stress periods with their abutting relationships. Three tectonic stress periods are determined and the sequence of the tectonic stress periods is NE-SW, NW-SE, and NEE-SWW. The results are consistent with other tectonic stress measurements for both the region and the locality.

By Fred D. Gustafson

With the postwar emergency for new housing and for new industrial buildings, much research has been done on lightweight aggregates for use in concrete and plaster. The trend toward lighter weight aggregates to relieve the dead load on the higher, steel frame- work buildings started toward the end of the last century. Progressively the requirements be- came more stringent, crushed bank slag, weighing 80 lb per cu ft as com- pared to 100 lb for crushed rock, was supplemented in some sections by foamed slags and expanded shales weighing from 40 to 60 lb per cu ft. In other sections cinders were used weighing from 40 to 50 lb, including sand. Sections favored with more recent vulcanism turned to pumice weighing from 30 to 60 lb, whereas other localities made use of diatomite, from 28 to 40 lb. Exfoliated vermiculite weighing from only 6 to 10 lb per cu ft came into use. As the search for lighter weights in aggregates continued so did the search for other desirable properties such as nailability, ease of cutting or channeling, and good insulation to both sound and heat. This search eventually led to a widespread interest in the expansion of perlite, or similar volcanic glasses, with the result that in 1946, the Office of the Housing Expediter' listed eleven firms reporting the operation of processing plants either on pilot or commercial scale producing aggregates weighing from 2 to 16 lb per cu ft.

Jan 1, 1949

By A T. Job, M L. Edgar, P R. McAree

Characterising ores in-pit and in real-time presents a significant value opportunity for the mining industry. Hyperspectral imaging systems are proposed as an enabling technology to achieve this real-time characterisation. This paper considers the application of a hyperspectral imaging spectrometer mounted on a shovel. We define the performance requirements for such a spectrometer and associated subsystems during a typical dig-load cycle. The relatively high swing rotation speed of the shovel requires approximately video-rate exposure times to achieve good spatial resolution. We analyse a selection of components against these requirements and find that suitable commercial spectrometers, detectors and optics appear fit-for-purpose. Automated, real-time spectral classification systems are also available, with only relatively modest requirements for processing power. The paper argues that at near peak solar illumination, a system for field deployment at the required sensitivity is viable using only commercial off-the-shelf components.CITATION:Job, A T, Edgar, M L and McAree, P R, 2017. Real-time shovel-mounted coal or ore sensing, in Proceedings Iron Ore 2017, pp 397–406 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Kalgoorlie is the main mining centre of the Western Australian Goldfields. Its famous Golden Mile' has been noted for the exceptional width and richness of its goldtelluride lodes. Since the mid-1890s production on the major mines has been maintained practically continuously.Rich ore, though not as plentiful or as rich as formerly, is still (1948) being mined in places. Unexplored areas still remain within the main auriferous belt which offer reasonable chances of success with intensive exploration.Much detailed information has accumulated in recent years through the geological mapping of underground workings by some of the larger mining companies. The purpose of this paper is to correlate observations made in most of the accessible old and recent workings in the mines of the Lake View and Star group and elsewhere.GENERAL GEOLOGYRock TypesThe rock formations are:-1. Fine-grained (older) greenstones, locally referred to as calc schists. There were originally pillow lavas and other flow rocks of basic composition, now extensively chloritised and/or carbonated. Pillows and fragmental flow- tops are recognisable. Intercalated with flows near the top of the series are several beds of sediments.2. Graphitic slates and other more arenaceous sediments.Although referred to as slates, they are rarely more than well-bedded shales with poorly developed fracture cleavage:Thick bands of felsitic rock are found in places.

Jan 1, 1952

By Mark A. Jirsa

The Biwabik Iron Formation is a ~1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern- most extent by ~1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones?each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. ©2007 Elsevier Inc. All rights reserved. Keywords: Iron-formation; Mining; Fibrous; Mineralogy; Metamorphism.

Jan 1, 2007

By Firth B. A

The flotation of fine coal (minus 0.5 mm) often requires the addition of an insoluble hydrocarbon collector to apparently promote the adhesion of coal particles to air bubbles. A series of experiments was conducted using a radiotracer and narrow size fractions of clean coal to determine the effect of particle size distribution, collector addition rate, desliming of feed and emuIisification of collector on the distribution of collector between the different size fractions. The concentration of collector per gram of each size fraction was found to be approximately proportional to (average particle size)-2 except if the collector was emulsified prior to addition, the dependence altered to approximately (average particle size)-1. Mechanistic consequences are discussed.

Jan 1, 1982

By Josh Swank

Albert Einstein once said, ?the important thing is not to stop questioning.? In the mining industry, a lack of inquisitiveness may lead to a blissful ignorance but it certainly will not increase efficiencies. While one may claim necessity is the mother of invention, questioning and analyzing how methods and systems can be improved is the catalyst to discovering necessities. Understandably, when working in the middle of Canada?s oil sands, where trucks operate around the clock every day of the year, it is nearly impossible to pull the nose from the grindstone long enough to provide thorough analysis. But, fortunately, some manufacturers/inventors have assisted by examining the process and the ensuing headaches within this application.

Jan 1, 2013

By Rameshwar Sah, Bharath Kumar Shanmugam, Govinda Raj Mandela, Marutiram Kaza, Harsha Vardhan, Harish Hanumanthappa

Iron ores obtained from different sources differ in their chemical and physical properties. These variations make the process of grinding a difficult task. The work carried out in this context focuses on three different samples of iron ore, viz., high silica high alumina, low silica high alumina, and low silica low alumina. The grinding process for all the three iron ores is carried out individually in Bond’s ball mill and the total retention time taken by each iron ore sample is calculated. The present investigation focuses on utilizing the calculated retention time of the iron ore as a standard grinding reference time to the laboratory ball mill for optimizing the grinding time of each ore. The desired P80 (150 μm) with an acceptable range of hematite liberation (> 75%) was obtained in the laboratory ball mill after reducing 6 min from the total retention time taken in the Bond ball mill.

By Rameshwar Sah, Bharath Kumar Shanmugam, Govinda Raj Mandela, Marutiram Kaza, Harsha Vardhan, Harish Hanumanthappa

Iron ores obtained from different sources differ in their chemical and physical properties. These variations make the process of grinding a difficult task. The work carried out in this context focuses on three different samples of iron ore, viz., high silica high alumina, low silica high alumina, and low silica low alumina. The grinding process for all the three iron ores is carried out individually in Bond’s ball mill and the total retention time taken by each iron ore sample is calculated. The present investigation focuses on utilizing the calculated retention time of the iron ore as a standard grinding reference time to the laboratory ball mill for optimizing the grinding time of each ore. The desired P80 (150 μm) with an acceptable range of hematite liberation (> 75%) was obtained in the laboratory ball mill after reducing 6 min from the total retention time taken in the Bond ball mill.