Search Documents

By G. L. Palmer

"Abstract- ln 1986, anomalous sampling results for heavy minerals were obtained at various sites in Namaqualand on the west coast of the Cape Province. Drilling in 1987 at Graauwduinen penetrated up to 35 meters of heavy mineral-bearing Tertiary sands which extend several kilometers inland from the coast. The heavy mineral suite includes ilmenite, rutile, leucoxene, zircon and monazite, along with garnet, pyroxene and amphibole. Three deposits are recognized, two of which comprise the resource to be mined by Namakwa Sands Limited, a recently formed Anglo American Corporation subsidiary company.Mineable reserves in excess of 500 million tonnes have been delineated, sufficient to sustain mining for over 35 years at projected production rates. During the feasibility study, on-site investigations included test mining at various sites to assess mineability and to provide material for metallurgical testing in a pilot plant located at the site. Ilmenite produced at the mine will be smelted at a new facility to be built at Saldanha Bay . Saleable products comprise titania-rich slag, pig iron, zircon and rutile.During the exploration phase, company environmental guidelines were established and monitored. The feasibility study incorporated a Class 1 Environmental Impact Report, the contents of which were made public following the principles of the Integrated Environmental Management legislation."

Jan 1, 1994

By Hongpu Kang

The fully mechanized top coal caving mining method has been the main mining approach for thick coal seams with high output and efficiency in Chinese coal mines. The gateroads for the top coal caving mining faces should be driven along the floor of the thick coal seam with a part of the seam as roof. The support of the gateroads is commonly difficult because of the low strength and broken structures of the coal seams, and the increasingly large section of gateroads meeting the need of greater and greater face coal output. Based on the analyses on the geomechanics properties and production conditions of the top coal caving mining, the influences of the top coal caving mining parameters on the stability of gateroads, including mining thickness and face length, are studied. The deformation and damage features of the rock mass surrounding the gateroads with the top coal seam as roof are investigated, the interaction of the support with the surrounding rock mass, the support theory are studied. The bolting design method and criteria, bolting forms and parameters for the gateroads with the top coal as roof are put forward. The rock bolting components, including bolt bars, face plates, cable tendons, meshes, and steel straps, are introduced. Finally, the gateroad bolting effects are evaluated through a typical case study on the basis of field monitoring data, such as the displacement of surrounding rock mass and the forces along bolts and cables.

Aug 1, 2013

By Lionel A. York

THE first application of the cementation process took place in the year 1864, according to H. Standish Ball, when a break in the brickwork lining at a depth of 270', in one of the Rhine Preussen pits near Homburg, was sealed by running in milk of cement from the surface by means of a small hand pump. At about the same time Monsieur Portier adopted the method in France for repairing breaks in shaft lining. Figure 1 is descriptive of the Portier system and is of interest when compared with modern practice. During the next thirty years numerous attempts were made to improve the process; the general method used in sinking being to put clown bore holes outside the perimeter of the shaft for the purposes of injection. The cementation process was first recognized as an important as-set to mining in 1896 when Monsieur A. Francois developed his method of boring and injecting inside the shaft below the permanent water level. The Francois cementation process rapidly attained fame on the Continent and many shafts were sunk by its use in France, Belgium and

Jan 1, 1961

By C. H. van Eendenburg

"Installation of a 3.6 km long raw coal conveyor in the Balmer open pit was undertaken to improve over-all haulage efficiency. This paper covers the rationale behind this project, system design and construction aspects and initial operating experiences. The majority of the construction work was performed by our own personnel. Where feasible, used equipment was installed to reduce capital cost and facilitate a tight construction schedule.BackgroundWestar Mining Ltd's Balmer Mine is located in the British Columbia Rockies, just outside of the town of Sparwood in the southeastern corner of British Columbia. The open pit mine, which has been in operation since 1969, currently produces about 6 million clean tonnes of coal per year, mostly for the metallurgical coal export market. Run-of-mine coal tonnages total between 9 and 9.5 million annually and waste removal volumes exceed 30 million bank cubic metres.The mine is a truck/shovel operation; loading equipment includes nine electric shovels, five front-end loaders and a hydraulic backhoe. The truck fleet consists of 40 units of 154-tonne, 181-tonne and 315-tonne capacity. The newer 154-tonne trucks are used for coal haulage for which they have been equipped , with tailgates to maximize their coal carrying capacity."

Jan 1, 1990

By Peter M. Watt

The objective s of this paper are: (a ) to examine and discuss the burdens we place on our extractive industry; (b) to compare the levels of taxation in Canada with those in other countries; and ( c) to suggest certain broad parameters within which our taxation policies may be made more rational and stable. Among the burdens identified are taxation, the ownership and use of our resources, environmental issues and the rather emotional issue of so-called 'super profits'. Finally, the paper will address certain broad but key areas of policy which need attention and agreement if our tax system is to be made more rational. Such areas include: whether and if so why the extractive industry should be given incentives;. what circumstances, if any, justify a 'higher' than normal' level of taxation, and, ?if the concept of economic rents is a justifiable one, how might a basis for them be established which recognizes the fluctuating value of much of the industry's output. Note: The paper was written before the 1977 Federal and Provincial budgets were presented. Consequently, the paper does not reflect any changes proposed in these budgets.

Jan 1, 1977

By Richard R. Walker, John J. Watkins, Allen C. Amos, Matulich. Angelo

THE KIDD CREEK MINE is located within the Abitibi greenstone belt, near its west end, in an area known as the Porcupine mining camp (Fig. 5). The Abitibi belt, long known for its many major gold and base metal deposits, is the largest Archean (early Precambrian) greenstone belt within the Canadian Shield. In the Porcupine area, the greenstone belt is composed principally of Keewatin (older Archean) basic to intermediate volcanics, with subordinate felsic volcanics developed• locally. Greywacke, mainly of volcanic derivation, occurs associated with and overlying these volcanics. Timiskaming (younger Archean) sediments, principally coarse clastics, unconformably overlie the Keewatin volcanics and sediments. The reader is referred to Goodwin and Ridler (1970) •r. for a more comprehensive description of the Abitibi belt.

Jan 1, 1974

By The Staff

"IntroductionThe published information concerning treatment of uranium ores has been very limited as far as Canadian ores are concerned. Such information has dealt mainly with refining processes for concentrates or rich ores, designed to recover radium rather than uranium; these methods could not be economically applied to low-grade ores.The purpose of this paper is to describe treatment possibilities for some of the .ores that have been treated at the Mines Branch, and .to show how the character of these ores influences methods and results.What is a Uranium Ore?Prospecting for uranium has been extremely active during the past two years and a great many occurrences of radioactive minerals have been recorded. Such prospecting has been based to a large extent on the use of the Geiger counter in the fie1d. This equipment is an invaluable aid when the results are properly interpreted.Most definitely, indications of high radioactivity do not always prove the presence of a valuable orebody. First we have to determine:(1) Is the radioactivity due to uranium or to thorium. There is no immediate market for thorium.(2) Can the uranium in the ore be economically recovered.Chemical analysis is the most exact method of determining uranium content, but a fair estimate of the uranium, and also of the thorium, content can be made from the difference in gamma and beta activity. The Mines Branch guards against misinterpretation by determining both beta and gamma activities and, if more than a minor amount of thorium is indicated, then a Chemical analysis is made."

Jan 1, 1950

By D. K. Fountain

"High metal prices and advanced technology in open-pit mining methods have resulted in considerable interest in the development of large, low-grade mineral deposits. Brenda Mines Limited is presently testing such a deposit of copper-molybdenum mineralization near Penticton, British Columbia.The mineralization of economic interest at Brenda has a total metallic sulphide content of between 1 and 1.5 per cent. This sulphide content approaches the limits of detectability of standard geophysical methods. How-ever, due to a favourable geological environment, it has been possible to utilize the Induced Polarization Method to outline the mineralization at the Brenda property."

Jan 1, 1968

By Adam Moore, Ryan Gillespie, Jarrett Quinn, Audrey Walters, Peter Radziszewski

"Vale Long Harbour Processing Plant (LHPP) was designed to process Voisey’s Bay nickel concentrate into finished nickel and associated copper and cobalt products. The plant includes a secondary grinding circuit comprising two Stirred Media Detritors (SMDs) operating in parallel. The ultrafine grinding circuit was designed to process concentrate at a rate of 33 t/h and produce a ground product (P80) of 20 µm to feed the leach circuits. Start-up of the grinding circuit at LHPP was undertaken in December 2014.The objective of this paper will be to describe the design, commissioning, start-up and performance of the secondary grinding circuit with a focus on the two Metso SMD-355-C mills. Following a brief overview of Vale’s LHPP and the SMD technology, the paper will review the design of the SMD secondary grinding circuit from lab tests through to scale-up performance prediction. This will be followed by the results of circuit commissioning outlining some of the issues raised and addressed after which SMD performance will be outlined. Specifically, the SMD circuit grinding performance will be examined since start-up which will include the effect of media size and wear on grinding. Furthermore, impeller wear will be examined by determining initial “shear volume” and worn “shear volume” as well as its effect on mill power and the means to maintain it. The paper closes with a discussion on grinding performance."

Jan 1, 2016

By D. C. Downing

"I THANK YOU for the invitation which The Mining Society of Nova Scotia extended, originally to Gordon Berry, manager 'of our Point Tupper Refinery, to join you at this meeting and discuss refining and petrochemicals in their relation to this region. There are natural advantages in Nova Scotia which have made possible, and will continue to make possible, sizeable developments both in petroleum refining and in chemicals. Equally, however, as is the case everywhere, there are certain constraints. For clarity in this presentation, I will state some of these constraints right at the beginning. First, of any future developments from now on, only a small proportion of the products can be expected to go into local markets. I can make the point best with a few figures. Petroleum companies all have market forecasts. None ever work out to be perfect, but the trends are relatively predictable and the orders of magnitude are certainly correct. Estimates for the use of all refined petroleum products in the four Atlantic provinces are:"

Jan 1, 1973

The use of QemSCAN in providing mineralogical input to detailed ore and product characterization has proved of immense value in recent years. In this paper, a brief review of selected Cu-case studies is presented to demonstrate the versatility of automated, quantitative mineralogy by QemSCAN. This versatility ranges from measurement and analysis strategies through to data processing and presentation. As a rapid diagnostic service, it is common to find that only grain size, the degrees of liberation and/or ore mineral modal mineralogy are of interest. By contrast, the detail afforded by the simultaneous determination of both gangue and ore minerals can alert mineral engineers to fatal flaws and attributes deleterious to processing that are directly a function of silicate and other gangue mineralogy. Examples of the latter effects include the influence of micaceous minerals and acid consuming species, while the former include fluorine minerals, which can provide both processing and environmental challenges.

Jan 1, 2007

By D. Yuan, L. Yan, R. Kalanchey, M. J. Collins, I. M. Masters

Pressure oxidation tests have been conducted by Sherritt for a refractory gold-silver project located in China. The feed contained 39 g/t Au and 970 g/t Ag; the major gold-bearing minerals were pyrite and arsenopyrite. Since the feed contained a significant amount of silver, which can be refractory to cyanide leaching after pressure oxidation due to the formation of argentojarosite, the test program included investigation of methods to enhance silver recovery. The "lime boil" process proved successful and was incorporated into the flowsheet. Gold extraction from the lime boil product solids was 95 to 98%; silver extraction was up to 94%.

Jan 1, 2011

By R. A. Price

The base of the biozone of Olenellus is accepted as the most universally applicable criterion for defining the base of the Cambrian System. The use of this definitive criterion is restricted by important practical considerations. In the southeastern Canadian Cordillera this zone appears to truncate the basal ortho-quartzite of a west to east marine -transgression. This transgression began in Interior British Columbia in the Late Proterozoic and terminated in the region of the present Rockies in the Late Waucobian. Most of the material deposited by the transgressing sea originated in the eastern positive element 'Laurentia' and was transported over the intervening low Proterozoic-Windermere erosion surface. The configuration of the advancing shoreline and the distribution of the sediments were controlled by the tectonic activity of positive elements in northwestern Montana (Montania) and in the Fairmont Hot Springs-Radium area of British Columbia.

Jan 1, 1956

By A. G. Roach

HISTORY AND LOCATION SEAL HARBOR GOLD MINES, LIMITED, was incorporated in January, 1934, to take over 116 acres of mining lands in the Stormont gold district, Guysboro county, Nova Scotia. The nearby ten-stamp Mulgrave mill was also purchased, and since that time 974 acres of adjoining properties have been secured from the Government by direct lease. The property is served by a motor road and is about two miles from the village of Goldboro, situated on the shore of Isaac's harbour. The bulk of ?the supplies are brought in by coastal steamer from Halifax, a distance of about 100 miles, since the nearest railway connections are at Antigonish, some 40 miles distant. EARLYY WORK The Seal Harbor properties include the old Partington and Beaver Hat mines. A small tonnage of ore was mined from each and treated on the properties in stamp mills, which were later torn. down . A survey of old records shows that this ore averaged about $8.00 gold per ton. Development work by the present Company was confined to the 100-foot level until February, 1935, but after that rime the incline shaft was deepened to 425 feet and the 300-foot level was explored east and west of the shaft. Six belts of ore were intersected to the west of the shaft. The ore from these belts was hand sorted and the ore portion was put through the 10-stamp Mulgrave mill to defray operating expenses and to serve as a sample of the deposits. The average recovery per ton from this sorted ore was $6.10. Samples of the ore were sent to the testing laboratories of the Mines Branch, at Ottawa, and of Canadian Industries, Limited, at Toronto. Recommendations from both of these authorities were for removal of the coarse gold by concentration and barrel amalgamation, followed by cyanidation of the residue.

Jan 1, 1937

Why A Friction Hoist? B EFORE discussing the equipment, it would be instructive to review the factors that influenced the management of Opemiska Cop-per Mines to purchase a friction hoist rather than a conventional double drum hoist. The mine required that 250 tons per hour be hoisted from a depth of 2,100 feet. They also specified that the top speed should not exceed 1800 feet per minute. Eight ton capacity skips in balance and a maxi-mum hoisting speed of 1725 feet per minute would meet the required <Output on a duty cycle as follows: Loading time Creep away from loading pocket Accelerate (at 2.5 ft/sec2) 10 seconds 5 seconds 11.5 seconds Full speed run Decelerate (at 2.5 ft/sec2) Creep into dump Cycle time Trips per hour Tons per hour 72 seconds 11.5 seconds 5 seconds 115 seconds 31 31x8 = 248

Jan 1, 1962

By W. Leblanc, J. C. Marsh, D. Kettle, J. Tompkins, G. Hartley

"The Lingan Mine is the newest of the four operating collieries of the Cape Breton Development Corporation and is located on the east coast of Cape Breton Island. Development of slopes began in 1969 using four Dosco Roadheaders. Production commenced in October 1972, when a partial extraction section utilizing a continuous miner, loader and shuttle car was installed. A second Joy unit is scheduled to begin production early in 1973. This paper describes the production and development operations, the ventilation system and the equipment in use at the mine."

Jan 1, 1973

The Challenges in Mining _Large expensive assets that are not being utilised as well as they should _?Silo? operations plan, schedule and execute in isolation?poor visibility across the Value Chain _Disruptions or unforeseen events have serious upstream and downstream impacts _Exacerbated by multiple information systems, mostly spreadsheets _Strategic simulation (supply and demand) is often poorly Handled

Nov 1, 2011

By J. Janeson

Wall control at the Pipe Open Pit is of primary importance in ensuring the long-term stability of the operation, while keeping costs to a minimum. Blasting techniques have been adapted to the variations in competence and structure of the wall rocks. A portion of the perimeter wall is being developed in incompetent peridotite . A recent change in pit slope design provides a wide safety berm on alternate benches. A support program which consists of pinning the crests of wide berms with vertical reinforced concrete dowels and horizontal bolting of walls shows evidence of increasing the stability of the pit walls. This paper describes the blasting and support techniques which are contributing to successful wall control in the Pipe operation.

Jan 1, 1979

By John Vergunst

"This paper traces the development of Ontario &apos;s cap lamp standard. Over the years, numerous Coroner&apos;s Juries investigating fatal mine accidents have made recommendations with respect to underground lighting. As well, recommendations to improve mine lighting have been made by two Commissions, investigating mine safety in Ontario.During the past few years, the performance of any cap lamp worn by miners involved in serious accidents, have been measured by the Mining Heal/h and Safety Branch. Large variations in light output were found between and among cap lamp types. These variations have been attributed to the lack of quality control on the bulbs, design of the cap lamp head piece and in some cases, poor maintenance.In 1986, a series of underground tests were conducted to establish the minimum light output from cap lamps required to visually identify loose ground. The results of these tests indicated that a cap lamp should produce a minimum peak illuminance of 1500 lux measured at 1.2 metres from the light source. On May 30, 1987, Ontario became the first province in Canada to legislate the minimum amount of light required to visually assess ground conditions. INTRODUCTIONPoor lighting has been identified as a factor which can contribute to mining accidents. Over the past decade, several Coroner&apos;s Juries as a result of inquests into mining fatalities, have recommended improved lighting in mines.The Joint Federal-Provincial Inquiry Commission into Safety of Mines and Mining Plants in Ontario, was appointed to report upon the adequacy of existing arrangements and practice s that may affect safety. This Commission completed their report in April 1981, and recommended that inadequate lighting be investigated as a possible cause of all reportable underground accidents, and that a comprehensive research programinto mine lighting be undertaken.In response to the first recommendation, the Mining Health and Safety Branch of the Ministry of Labour, hereafter referred to as the Branch, initiated a program to measure lighting levels in all fatal accident investigations where inadequate lighting was a possible factor."

Jan 1, 1989

By A. Broussaud

The paper describes the advanced grinding control system implemented at Newmont Ahafo gold mine, Ghana in 2009 and 2010. It shows how the different components of the Advanced Process Control (APC) system cooperate for increasing plant performance. The SABC circuit processes hard rock from different pits mixed with a variable proportion of oxides. The control strategy is designed to address specific disturbances, including start/stops of pebble crushers, unavailability of oxides, changes in rock size distribution resulting from segregation in the stockpile, and changes in ore type and hardness. The system consists of an expert system per se with extensive use of fuzzy logic, supplemented by an online dynamic model of the process used as a soft sensor, a VisioRock? rock size measurement system over SAG mill feed before addition of recycled pebbles, and an AudioMill? system to analyze the SAG mill sound and detect impacts on liners. All these components are embedded in the same OCS© software platform, which, among other benefits, makes it easy to support the entire system remotely. The paper details the physical constraints and the variables that are manipulated. It describes the control strategy and the contribution of each component of the system. It also describes the project implementation and the performance of the system. In addition to a strong involvement and support of management, the very good acceptance of the operators has been facilitated by the remote access system that made it possible to immediately modify the system each time it was needed during the baby sitting phase. The system made it possible to increase gold production significantly through increases in tonnage and recovery thanks to a better control of the grind size through a stabilization of the secondary ball milling circuit and an improvement of the operating conditions of the classifying cyclones.

Jan 1, 2012