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By B. Tiryaki, M. Ayhan, O. Z. Hekimoglu

Coal shearers are one of the major sources of dust and fines in underground coal mines. Despite considerable research investigations, no comprehensive in situ investigations coupled with extensive laboratory studies on the effects of drum design on generation of dust and fines have been found. It may be for this reason that many major shearer drum manufacturers persistently employ a certain drum-lacing pattern on current coal shearers, which is believed to cause excessive dust and fines in coal mines. This paper shows how respirable dust and fines are minimized under near-identical conditions when the drum lacing pattern was changed from a triple-tracking to a single tracking arrangement. A series of laboratory trials simulating in full scale the practical cutting action of tools was followed by extensive long-term underground trials during production operations in OAL (Cayirhan) Lignite mine in Turkey. The results are presented and discussed, and recommendations for proper drum-lacing in terms of respirable dust and fines are made.

Jan 1, 2002

By John Hansen

This paper has been written for presentation at the 103rd Annual General Meeting of the Canadian Institute of Mining, Metallurgy, and Petroleum, April 29 to May 02, 2000. The paper addresses blast pattern fragmentation and diggability versus the blasting technique used. RESUME The author is the Vice President for Thunderbird Mining Systems. In this capacity he manages the mine site installation of surface mining mobile equipment monitoring and navigation systems. These systems are onboard instrumentation and software systems designed to: ??measure and log mobile equipments? production and health; and ??direct the equipment operators via onboard displays that show comprehensive maps and engineering instructions. The author is a mining engineering graduate from the Royal School of Mines. His work experience includes front line supervisor and mining engineer for Hudson Bay Mining & Smelting, mining engineer for Teck Corporation, and mining consultant for PriceWaterhouseCoopers.

May 1, 2001

By D. Runnels, Daniel Roy, Ricardo Esteban, J. Torrealba-Vargas

"An intuitive way to reduce power consumption in grinding operations is to feed the grinding circuit with finer feed by enhancing blasting and fragmentation control. The optimization of blasting with the objective of minimizing power consumption in grinding is not new.The study was based on a Canadian mine that processes a very hard ore. BBA conducted blasting/fragmentation and grinding circuit surveys in 2014. The results of the exercise were used to develop a base case model to simulate the effect of blasting in the operation on the grinding circuit. Tools for fragmentation simulations, particle size measurement and crushing/grinding simulations were used with the objective of reducing the OPEX costs including power consumption.The paper describes the steps involved in the model optimization as well as an economical evaluation of the OPEX savings.INTRODUCTIONIn 2014 BBA was retained by one of its clients to conduct a crushing and grinding survey. The objective of the survey was to update the grinding circuit model with production data and also to develop a tool to investigate opportunities for process improvement.A second phase of the study involved the development of drilling and blasting and crushing models. The models were used to diagnose the operations and to investigate opportunities for process improvement.The objective of the present study is to describe the approach and to identify potential improvements to overall mine site operating costs by better integrating mining and milling operating costs with blasting and grinding models."

Jan 1, 2016

Building off the enthusiasm generated by Credit Suisse First Boston on the potential benefits of an industry-wide effort to market gold jewellery, a group of gold producers, led by Randall Oliphant, CEO of Barrick Gold, decides to investigate the long -term impact of launching a significant marketing initiative to stimulate demand for gold jewellery. The group establishes an international Steering Committee representing producers of differing sizes, members and non-members of the World Gold Council. This Committee comprises representatives from AngloGold, Barrick, Gympie Gold, Kinross, Randgold, and Sons of Gwalia and is supported by the Australian Gold Council, the Gold and Silver Institute, and CSFB. The Steering Committee hires McKinsey to assist it by conducting an independent review of whether investment in a large-scale marketing initiative for gold jewellery would be effective in increasing demand for gold, and ultimately of significant economic benefit of the gold industry. Based on McKinsey?s review* and its own discussions with key stakeholders across the industry, the Steering Committee strongly believes the case for marketing is compelling and sufficiently proven to persuade the industry to undertake a major initiative over the next few years. The Steering Committee, supported by McKinsey, conducts briefings with a range of gold producers to share its findings and to understand producers? perspectives on an industry-funded marketing campaign. The Steering Committee is asking for your support to bring this industry-funded marketing campaign to life.

May 1, 2002

By G. A. Moruzi

Two sulphide dust secondacy explosions have occurred in the mines of the SUdbury operations of Falconbridge Ltd. during the past 18 months. 'Ihe main similarity between the occurrences is that they both happened in vertical crater retreat blasthole stopes. A relatively high p:,v.tier factor was noted in both instances. other details are enumerated and examined, as well as some results of tests done by Noranda Research on company ore samples.

May 11, 1988

By G. T. Lapidus, R. Zárate-Gutiérrez

Selective leaching of lead from a Pb-Ag-Zn concentrate with hydrogen peroxide in citrate solutions was studied at room temperature. Leaching tests were performed, varying the H2O2 concentration and the solid-liquid ratio, holding the solution pH constant at 7, and the citrate concentration at 1 M. Lead extractions of 100 % were achieved with 4 and 5 times the stoichiometric quantity needed to form elemental sulfur, with only a small amount of metal impurities dissolved (Ag, Zn and Fe). The lead solubility limit at those conditions was found to be ~21 g L-1. X-ray diffraction analyses of the leach residues were free of galena (PbS), while other metal sulfides, such as sphalerite (ZnS), chalcopyrite (CuFeS2) and pyrite (FeS2), were basically unaffected.

Jan 1, 2014

By C. G. Anderson

As the global demand for copper and gold steadily increases and the need for environmentally sound processing also grows, successful hydrometallurgical treatment of enargite (Cu3AsS4) concentrates has come to the forefront. This type of concentrate contains considerable arsenic so that successful arsenic fixation, for example as scorodite, is of the essence. This paper outlines the successful application of low temperature and low pressure nitrogen species catalyzed (NSC) hydrometallurgical pressure oxidation of enargite concentrates. The successful stabilization of the arsenic as an iron arsenate compound is discussed. Also, the use of experimental design software is highlighted as a process application and optimization tool.

Jan 1, 2006

By Ltd. (CYMCO) Technology Center Yunnan Metallurgical Group Co., S. Jian, T. Song, J. D. Miller

"As sulfide zinc ore deposits become exhausted, nonsulfide zinc ore deposits become the other resource for zinc production. However, flotation for zinc recovery from nonsulfide deposits is much more difficult than the flotation of sphalerite from sulfide deposits and may become an option for zinc production only if a suitable processing technology is developed. In this regard, research efforts are being devoted to the flotation of nonsulfide zinc oxide minerals. Some common methods which have been used for the flotation of zinc oxide minerals include sulfidization-flotation, activation, and direct flotation with anionic and cationic collectors. The traditional flotation techniques have low efficiency and difficulty in separation and recovery of the zinc minerals from gangue minerals, for example, smithsonite (ZnCO3) from other carbonate gangue minerals and hemimorphite (Zn4Si2O7 (OH)2·H2O) from silicate gangue minerals. In this study potassium lauryl phosphate was evaluated as a collector for the flotation of nonsulfide zinc minerals. Results from contact angle and microflotation experiments at pH 6–9 show that hemimorphite (Zn4Si2O7 (OH)2·H2O) can be floated from quartz and that smithsonite (ZnCO3) can be floated from calcite. However, when dodecylamine, which is a common collector reported in literature for the flotation of nonsulfide zinc minerals, was used as collector, no significant difference between nonsulfide zinc minerals and gangue minerals was observed at any pH value. Initial evaluation suggests that potassium lauryl phosphate is effective at low concentration and may be a promising collector for zinc oxide mineral flotation.INTRODUCTIONBefore the twentieth century, zinc was mainly produced from nonsulfide ores (Large, 2001; Gilg, Boni, & Cook, 2008). With the development of differential flotation processes in the late 19th century major production switched from nonsulfide zinc sources to sulfide zinc ores (Hitzman, Reynolds, Sangster, Allen, & Carman, 2003; Gilg et al., 2008). However, as it is becoming more difficult to find new sulfide ores, recovery from nonsulfide deposits is being considered. Nonsulfide flotation for zinc recovery is much more difficult than the flotation recovery of sphalerite from sulfide deposits and may become an option for zinc production if a suitable technology is developed. Zinc and lead oxide ores are difficult to beneficiate ores due to their similar floatability with gangue, high solubility in water, and the influence of slimes (Fa, Miller, Tao, & Li, 2005). In order to improve the performance of oxidized minerals, lots of effort is being devoted to this field of study (Ejtemaei & Mahdi, 2014)."

Jan 1, 2016

By Margaret Armstrong, Chris Roth

Abstract -Estimating ore reserves for vein type deposits is a two-stage procedure: first, calculate the geometry of the vein system, and second, estimate the grades within this system. The grade estimation can only be consistently performed if the vein geometry - its size, shape and orientation - has been correctly characterized. Getting the size and shape of the different veins right means that the ore tonnages will not be artificially inflated, e.g., by falsely classifying host rock as veins. Similarly, correctly estimating their orientation and location helps mine management decide on the appropriate mining technique, selective or not. When applying geostatistics to estimate the vein geometry all available information needs to be used and not just the standard lithologic indicator of being or not being in a vein.

Jan 1, 1998

By C. K. Wilton

"The Agnew Lake uranium deposits were discovered in 1953 following the discovery of the Elliot Lake deposits to the west. The original property was optioned to Kerr Addison Mines Limited who added additional claims by staking. Agnew Lake Mines Limited was incorporated in 1967 to develop the property and a shaft was sunk to 1040 metres and five levels developed before work was suspended due to low uranium prices at the end of1970.In 1974-75 the mine was dewatered and production started in 1977. By 1978 reserves were estimated at 10,000,000 tonnes averaging 0.35 kg. U10 , per tonne. Underground operations were terminated in 1980 although a uranium leaching operation was continued until early 1983.The deposits lie near the contact of Huronian metasediments with underlying Algoman granite. The sediments consist of arkose, conglomerate, argillite and quartzite with the uranium mineralogy mainly confined to oligomictic quartz pebble conglomerate. The higher uranium values are related to conglomerate with highest percentage of pebbles. The chief uranium minerals are uranothorite and monazite. It is of interest that the uranium thorium ratio differs appreciably from that of the Elliot Lake deposits. This fact along with the fact that the Elliot Lake sediments were deposited by paleocurrents from the northwest whereas the Agnew Lake sediments were deposited by paleocurrents from the northeast indicates widely separate sources for the deposits. It is suggested that the Agnew Lake uranium deposits are syngenetic placers deposited under anoxygenic atmospheric conditions."

Jan 1, 1986

By W. P. Nash, T. E. Mccandless

"Abstract - Detrital minerals of upper mantle origin occur in Holocene conglomerates, pediments and antmounds, and in Oligocene conglomerates in the Green River Basin of southwestern Wyoming. The minerals are derived from disaggregated eclogite and peridotite, and are similar to minerals found in mantle- derived igneous rocks such as kimberlite and lamproite, the primary host rocks for diamond. The Green River Basin bisects the lamproite fields of the Leucite Hills (Wyoming) and Kamas (Utah) and overlies the Archean Wyoming craton, which makes the region favorable for diamond occurrence. Lamproite is the favored host for the indicator minerals because unusual high-Fe salitic diopside macrocrysts from the antmounds and from the ~1 Ma old Leucite Hills lamproites to the northeast are compositionally identical. The salitic diopside is uncommon in other igneous rocks and could be a new indicator mineral for use in lamproite exploration. The Green River Basin indicator minerals are eroded from the ~29 Ma old Bishop Conglomerate, whose source area is the Uinta Mountains to the south. No continuous mineral train exists between the Uinta occurrences and those in the Green River Basin. Assessment of the minerals using established and new geochemical criteria indicate that they formed in an oxidizing upper mantle and were transported to the surface by either kimberlite or lamproite. The existence of cogenetic diamond is unlikely based on the mineral chemistry, but selective removal of diamond indicator minerals through weathering and fluvial transport cannot be excluded. Diamonds and mantle garnets are present in the northeastern Uinta Mountains, but they originated as part of the Diamond Hoax of 1872. A representative mineral assemblage from the true igneous host of the indicator minerals is required to fully establish their economic potential. Post-Oligocene erosion and Pleistocene glaciation have hindered efforts to locate a bona fide igneous source for the indicator minerals. Résumé - Des minéraux détritiques provenant du manteau supérieur ont été trouvés dans des conglomérats, des pédiments et des monticules de fourmis de l’Holocéne, et dans des conglomérats de l’Oligocène du Green River Basin, au sud-ouest du Wyoming. Ces minéraux sont issus du démantellement d’éclogites et de péridotites, et sont semblables aux minéraux trouvés dans des roches ignées provenant du manteau, comme les kimberlites et les lamproïtes. Ces dernières sont les roches hôtes du diamant. Le Green River Basin recoupe les champs à lamproïte de Leucite Hills, au Wyoming et de Kamas en Utah, et il surmonte le craton archéen du Wyoming, connu pour la présence de ses diamants. La lamproïte est l’encaissant privilégié pour les minéraux «indicateurs» parce que des macrocristaux exceptionnels de diopsides salitiques riches en Fer, provenant des monticules de fourmis et des lamproïtes de Leucite Hill (~1 Ma), au nord-est, ont des compositions identiques. Le diopside salitique est rare dans les autres roches ignées et peut être un nouvel indicateur dans la recherche de lamproïte. Les minéraux «indicateurs» du Green River Basin proviennent de l’érosion du Conglomérat de Bishop, daté de ~29 Ma, dont la zone source est représentée par les Uinta Mountains, au sud. Aucune continuité des gisements minéraux n’existe entre les affleurements de Uinta et ceux du Green River Basin. La détermination des minéraux, utilisant des critères géochimiques anciens et récents, indique qu’ils se sont formés dans un manteau supérieur oxydant et qu’ils ont été remontés à la surface soit dans des kimberlites, soit dans des lamproïtes. La genèse du diamant n’est que peu liée à la chimie minérale, mais le lessivage d’indicateurs minéraux du diamant par altération météorique et par transport fluviatile ne peut être exclu. Des diamants et des grenats mantelliques sont présents dans le nord-est des Uinta Mountains, mais sont associés avec le Diamant Hoax de 1872. Un assemblage minéral représentati"

Jan 1, 1996

By Adrian E. Scheidegger

"AbstractThe possibilities of deriving pertinent information about fractures in an oil pay from data obtained by core analysis are investigated. It is shown that it is possible to obtain an estimate of the fractured area per unit volume of the pay, and that the size of the fractures can be estimated if their shape is known. A suggestion of a routine procedure for the analysis of fractures is given.1.-IntroductionMany oil fields are producing essentially from cracks or fractures. Where this is the case, it is important to be able to obtain a knowledge of the size and distribution of those fractures in the oil pay. This knowledge has to be derived from the analysis of cores taken from the fields, as it is generally impossible to follow a fracture through the pay by direct means. The necessity of using statistical methods to extrapolate the meagre information obtained from the cores of the wells is therefore indicated.It is known that the fractures are much bigger than the diameter of the cores; thus, if they strike a core, the latter will generally fall into two pieces. The angle of the fracture with the vertical can be measured and, if oriented cores are taken, the exact position of the surface element representing the intersection of the fracture with the drill stem can be determined. Sometimes the edge of a fracture can be seen in a core. The number of •Cores that show such an edge can be noted. Of course, one has to be careful to distinguish between original fractures in the pay and fractures in the core caused by drilling operations. Only the former are relevant."

Jan 1, 1955

By Shuan-cheng Gu

Roof bed separation often occurred due to the deformation incoordination of surrounding rock following the excavation of mine roadway. Bed separation has effect on the bolts, and the estimation of the influence will directly affect the safety of support systems. In this paper, the hyperbolic function model to analyze the load transfer mechanism on the bolts was simplified as the exponential function form for easy calculation. An elastic-plastic analysis model of the bolt loading occurred by the bed separation was established. And the development low that the bed separation affected to the bolt loading was discussed. According to the parameters analysis of different separation values and locations, the influence law of the bolt loading caused by roof bed separation was summarized. Finally, the effects of bed separation were considered for the bolting design, it was able to provide a reference to the anchorage design of stratified rock.

Aug 1, 2013

By R. H. Duval

"In May 1936, Pamour started producing gold by cyanidation of flotation concentrates, and in 1939 was milling about 1, 600 tons per day.Refining records dating from 1939 show two oil-fired furnaces in use, (Rockwell type 46 11 x 29 11 inside oval shell).Refining time averaged 7. 83 hours during the year 1939, indicating a complete refining shift of about 9. 33 hours. That year appears to be characteristic of the period with regard to time required and results obtained.For that year total fineness (gold + silver) of the bars averaged 940 (approx.), but it frequently dropped below this figure, sometimes far below.Furnace lining life varied widely from three to seven or more months. Sillimanite was the standard lining but Mullfrax 41 was frequently used.For many years refining practice remained practically unchanged, and in 1960 procedure still consisted essentially of mixing a flux(% Composition Borax 41, Silica 11, Soda-Ash 11, Nitre 15, Mn02 22) with cyanidation precipitate in the ratio of l. 2 to l and heating to a medium heat (yellowishred, 2000° F) with a low flame for a long time. Time required was about 10. 5 hours per refining. Results were still much as detailed above.At this time it was decided to revise refining procedure, in an effort to shorten refining time and obtain consistently good bullion fineness."

Jan 1, 1965

By CIM Mineral Resource

On January 9, 2018, the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Council formed the CIM Mineral Resources and Mineral Reserves Committee (CIM MRMR Committee), which is a combination of the previous Standing Committee on Reserve Definitions and the Best Practices Committee. As part of its mandate, the CIM MRMR Committee updates guidelines for use by Industry, which include the Uranium Practice Guidelines. The 2024 CIM Uranium Leading Practice Guidelines were adopted by CIM Council on November 22, 2024, and supersedes the 2003 version. The main principles and guidelines relating to preparation of Mineral Resource and Mineral Reserve (MRMR) estimates are provided in the CIM Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines (MRMR BP Guidelines, as updated from time to time). The MRMR BP Guidelines provide information pertaining to metalliferous and other deposits and many sections are readily applicable to the preparation of MRMR estimates for uranium deposits. However, additional guidance is appropriate for uranium deposits due to the radioactive nature of uranium, and its amenability, in some cases, to in situ recovery (ISR) mining methods.

Nov 1, 2024

By J. Guha, el, G. Bouchard, W. Zuckerk, J. Carignan, G. Archambault

The Gwillim Mine, located 8 km northwest of Chibougamau, is underlain by two mafic volcanic cycles separated by a dominantly felsic cycle. These rocks are part of the Gilman Formation of the Roy Group. The mafic rocks are cut by weak shear zones containing the "North" and "Main" veins, both east-west striking gold-bearing structures dipping 75° to the north. The felsic cycle, which is also gold-bearing, contains textures suggesting a syngenetic origin. The Gwillim Mine presents an excellent opportunity for the study of what may be two coexisting gold deposits, a volcanogenic and a veine type.

Jan 1, 1984

By R. Heikkilä

A large research and development program called RYM PRE (Process Re-Engineering) has been active in Finland since 2010. As a part of the program, a work packet Infra FINBIM is focused on the development of new national process model, specifications and requirements for the whole Finnish Infra Industry. In the Infra FINBIM, total 15 companies and main owners and 3 research organisations are included. The work is further continuing. The main achieved results up today have been the first specifications and requirements of the BIM based total process for infra sector, about 30 different pilot projects for testing of the new design and construction process models producing a lot of results and observations, a new open information transfer format Inframodel3 based on LandXML standard, the achieved acceptance of the Building SMART organization for support of international development, utilization and extension of the format within the whole infra industry, processes, software and other technical equipment. An evaluation of the results and this work will be drawn.

Aug 1, 2013

By R. P. van Hille, N. Mooruth

Remediation of acid rock drainage (ARD) was performed within a linear flow channel reactor (LFCR) via a floating sulphur biofilm (FSB). A full sulphur species material balance was conducted in order to characterize the sulphide oxidation. The reactor was able to achieve an 82% and 93% conversion of sulphide with a hydraulic residence time of 2 and 5 days respectively. 92% and 55.5% of the converted sulphide reported to the biofilm as sulphur for the 2 and 5 day residence times respectively. The mass transport limitations within the biofilm were identified via a dissolved oxygen gradient profiling system.

Jan 1, 2011

By T. Marolt, J. Likar, E. Grøv, J. Žarn

"Underground structures are an integral part of the infrastructure of modern society and are used for a wide range of applications, including subways and railways, highways, not at least nuclear facilities. When the wider area is subject to earthquake activity, underground constructions should be analyzed on seismic and static loading. Observations showed that the underground structures have significantly less seismic risk than surface structures. Available methods allowed analyzing the magnitude of risk for different input parameters of seismic loads in different ground environment. Simulation of earthquake loading on underground structures, in the present paper is given the various aspects of analyzing the potential damage and instability of underground facilities. INTRODUCTIONThe development of methods and computing resources used for para-seismic engineering has finetuned the evaluation of the seismic strength of buildings and equipment. Reinforcements may therefore be decided, not simply on the basis of a reassessment of the hazard, which constitutes input data for the calculation of structures and equipment, but also on the basis of developments in para-seismic engineering. Underground facilities are an integral part of the infrastructure of modern society and are used for a wide range of applications, including subways and railways, highways, material storage, and sewage and water transport and not at least nuclear facilities. Although in the past showed that the underground structures are significantly less seismic risk than on the surface, the professional researches and their results are accessible. Seismic resistance of underground structures is analyzed from several aspects. The currently available methods allowed analyzing the magnitude of risk for different input parameters of seismic loads in different ground environment. For better interpretation of earthquake loading on underground structures, are given below the various aspects of analyzing the potential damage and instability of underground facilities in rock. One of the early studies which covered this are of investigation were prepared by Dowding and Rozen (1978). They grouped damages due to earthquakes in underground structures into three main categories:- damage from ground shaking- damage from fault dislocation- damage by earthquake-induced ground failures (e.g. liquefaction and landslides)."

Jan 1, 2015

By M. Maley, S. Burling, R. Ring

ABSTRACT The numerous global uranium deposits vary significantly in mineralogy, grade, and textural characteristics; therefore, information from traditional (or conventional) sources on the fundamentals of leaching uranium and gangue minerals is not always applicable when studying particular ores. Empirical studies can be effective in understanding leach systems and can lead to improvements in process design but there remains a lack of fundamental understanding necessary for ongoing process optimization as ore bodies continue to vary. ANSTO Minerals has undertaken a work program to address several fundamental questions about uranium leaching, including the unexpected impact for some ore types of leaching at high oxidation potential.

Jan 1, 2012