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By Patrick Andrieux

Numerous rock blasting design methodologies have been developed over the years, relating either to the primary objectives of blasting, such as the size distribution of the blasted material, or to its undesirable side effects, such as damage to the remaining rock mass. All existing methodologies, while of use, do have serious shortcomings. The question remains whether further improvements can be achieved in the field of practical rock blasting engineering. One approach that seems to hold promise is the relatively new matrix-based rock engineering systems (RES) methodology. It has been conceptually demonstrated that RES could be efficiently adapted to blasting. A brief overview of rock blasting design techniques and their main shortcomings is followed by the basic concepts governing rock engineering systems and a discussion on their pertinence to blasting. The paper concludes with a review of current efforts to develop a useful practical blast design tool using RES. SOMMAIRE Le potentiel d?application des systèmes d?ingénierie du roc aux tirs à l?explosif. De nombreuses méthodologies de conception d?abattage du roc à l?explosif ont été développées au cours des années, qui ont adressé soit les principaux objectifs des tirs, comme par exemple la granulométrie du matériel dynamité, soit ses effets secondaires indésirables, tels les dommages au massif rocheux. Toutes les méthodes existantes fonctionnent dans une certaine mesure et sont utiles - elles sont cependant pour ainsi dire toutes affectées par des limitations ou défauts plus ou moins sévères. La question demeure quant à savoir si des améliorations supplémentaires peuvent être apportées dans le domaine de la conception pratique des opérations d?abattage du roc à l?explosif. Une approche alternative qui semble prometteuse est celle relativement récente des systèmes matriciels d?ingénierie du roc (?Rock Engineering Systems?, ou RES). Il a été démontré de manière conceptuelle que les RES ont le potentiel d?être adaptés aux opérations de sautage. Une brêve revue des principales techniques de conception des tirs à l?explosif est suivie d?un énoncé des principes de base gouvernant les RES, ainsi que d?une discussion sur leur pertinence aux opérations de tir. Cet article conclut avec la revue d?un projet de recherche axé vers le développement d?une méthodologie de conception des tirs à l?explosif basée sur les RES.

May 1, 2002

By Robert D. Brown

The federal government kicked off the new budget season in November 1978, when Finance Minister Chretien announced a handful of proposed amendments to provisions of the federal Income Tax Act and Regulations affecting mining. (See Tax Notes in the January 1979 issue of the CIM Bulletin.) Declaring in his budget speech that these changes were in response to the report of the joint federal/provincial task force on resource taxation, Mr. Chretien tossed the ball to the provinces-" I want to take the lead here... I feel confident that the provinces will do their part". Quebec and Ontario, picking up the ball in their spring budgets, have announced favourable modifications to the provincial taxes on mining, with these moves being paralleled in the recent Manitoba budget, which proposes a flatrate mining tax to replace the previous controversial two-tier royalty. In the meantime, the federal government passed a host of amendments to the federal earned depletion regulations. The result is yet another batch of complex tax changes for the industry to note and digest, but this time with the hopeful factor that most of the changes are favourable to the industry. This article reviews the current status of the federal budget changes, comments on the Ontario, Quebec and Manitoba proposals, and reports on the changes to the earned depletion regulations that were passed by Order-in Council in March 1979.

Jan 1, 1979

By A. E. Reschke

Optimized mine planning of the Leeville Gold Mine, Nevada, necessitated the requirement for an average of 2540 tpd of high quality cemented rockfill (CRF) in primary stoping blocks and underhand cut and fill workings. To meet this requirement, a number of innovative design features were incorporated into the overall batching plant design. Foremost is the use of a dedicated skip to transfer crushed aggregate from surface down through the ventilation shaft to twin underground storage silos. Also, the use of a high shear colloidal mixer on surface to pre-slurry a cement/flyash binder with pipeline delivery to one of two separate underground CRF mixing stations was incorporated. Finally, the binder and aggregate are combined in a 9 m3 twin shaft compulsory type mixer before loading into teleram trucks for placement.

May 1, 2007

By C. V. Corless

THE origin of various types and groups of ore deposits was some years ago a subject of much controversy. To this statement the copper-nickel deposits near Sudbury afforded no exception. Not since the Report of the Ontario Nickel Commission, in 1917, has there been any serious discussion of the origin of this very important group. This may be because, from the opening-up of Murray mine by the British America Nickel Corporation until the recent work at Frood mine, no new ore-body of importance has been developed in the district. The controversy fifteen or twenty years ago between those who favoured the theory of magmatic segregation, among whom Dr. A. P. Coleman was the leading exponent, and those who considered that most, if not all of the Sudbury deposits could more satisfactorily be accounted for by the theory of replacement, will be remembered by many members of the Institute. Perhaps, as too often happens in controversial discussion, each side tended to overemphasize the importance of those geological phenomena which seemed to be most easily accounted for by the theory it favoured. A more balanced view would perhaps admit that replacement was probably predominant in the formation of most of the offset deposits, and magmatic segregation in that of most of the marginal deposits . But there is danger in generalization. Each body of ore should be studied by itself, and no general conclusion of this kind should be allowed to warp the judgment in making such a study.

Jan 1, 1929

By D. A. Garland, A. D. Jackson

"Alanx ceramic/metal composites are proprietary products developed by Lanxide Corporation who joined with Alcan to form Alanx Products L.P. in 1988. Alanx ceramic/metal composites are composed of silicon carbide in a combined alumina and metallic aluminum matrix. In laboratory slurry wear tests conducted by Alanx ceramic/metal composites have shown to perform well against other wear resistant materials. At the Kidd Creek Concentrator Alanx CG896 ceramic/metal composite was tested in two pumping applications, the primary cyclone feed pumps and the filter feed pumps. In both instances the wear rates of the parts made of Alanx CG896 were far less than the gum rubber parts traditionally used. As of year to date September 1992 the unit cost to repair primary cyclone pump parts has dropped 58% from 1991 figures. For the filter feed pumps the unit cost to maintain the pumps has dropped by 33% as compared to 1990 figures. The total savings represented by implementation of Alanx wear parts, based on projected year end unit costs for 1992, as compared to 1991 costs for primary cyclone feed pumps and 1990 figures for filter feed pumps, is $166,753. INTRODUCTIONAt the Kidd Creek Concentrator the cost to maintain the primary cyclone feed pumps and the filter feed pumps was a constant concern. Rubber wear part consumption was quite high and the manpower required was considerable. For 1991 the total cost to maintain five primary cyclone pumps was $244,062. The cost to maintain the filter feed pumps in 1990 was $72,076. A wear material was needed that would increase the time between repairs and that would increase the reliability of these pumps between scheduled shut downs."

Jan 1, 1993

By S. Bantubani, I. Mc Dougall, S. Arjun, H. Joubert, R. Hansraj

The requirements determining the design of the Söderberg electrode columns used in base metal applications are different to those of other industries. There is a strong trend to position the contact shoes above the furnace roof in order to reduce the risk of water leakages directly onto the furnace bath. Tenova Pyromet has adapted its proven electrode column design for application on base metal electric furnaces based on these requirements. The design modifications implemented as well as considerations regarding the overall electrode-roof-furnace arrangement are discussed. Equally important is the management of the Söderberg electrodes to prevent over or under baking. Tenova Pyromet has developed the AutoFurn™ furnace controller to not only optimise furnace operations, but to improve electrode management. An overview of the electrode management control philosophy implemented by AutoFurn™ is provided, focusing on intelligent electrode regulation, slipping and baking. INTRODUCTION Tenova Pyromet has developed an electrode system for use in base metal furnaces, which builds on the experience that Tenova has gained during the past 30 years with electrodes in the ferroalloy and base metals industries. In base metals applications, an important safety consideration is the minimization of water within the furnace and on the furnace roof. In addition, direct contact between copper equipment such as contact shoes and pressure rings and the contents of the furnace is discouraged. In a 3 phase AC furnace, three electrode columns transfer the electrical energy to the furnace bath. Both Söderberg and prebaked carbon or UHP graphite electrodes are in use in base metal furnaces. In each column, the electrode is held in position by a hydraulic slipping and regulating device, a pressure ring and contact shoes. The electrodes can operate in a submerged-arc or brush-arc configuration, where the electrode is immersed in the slag or a short distance above the slag (Mc Dougall 2013). The electrode equipment is divided into an upper and a lower electrode assembly. The self-baking Söderberg electrode is made from lengths of steel casings that are added to the top of the electrode column and welded into place. Carbon electrode paste is added to the inside of these casings and is baked to form a solid tip in the region of the contact shoes. The working platform that surrounds the area where new electrode casings are added, is electrically isolated from the building and each electrode is isolated from the others to ensure the safety of the personnel who perform the electrode casing additions.

Jan 1, 2019

By S. K. Paul

"This paper briefly describes the underground crushing and conveying system at Sherritt Gordon Mines' Ruttan Mine. A series of three steel-cord belted conveyors, with a total length of 2J55 metres and a total vertical lift of 407 metres, convey the muck from the underground crushing station to the mill at the surface. The maximum size of the crushed rock is 6 in. All the conveyors are provided with numerous safety and fire suppression devices. IntroductionThe Ruttan Mine of Sherritt Gordon Mines Limited is located 20 km east of the town of Leaf Rapids, 760 km north of Winnipeg. The orebody is multilensed, with lens width varying from 6 to 45 m. Ore production started in 1973 with the opening of a 10,000-tpd open-pit mine. Initial development of the underground mine was started in 1972 with the driving of parallel conveyor and access declines at minus-2507o gradient to the I 220-m level, and then the access ramp was further extended to the 1160-m level. Exploration drifting was done on the 1280-m and 1160-m levels from the access ramp. The final development plan for the underground project was approved in January 1977, and full-scale development and constructionwere resumed.At present, Ruttan Mine is in a period of transition from open-pit to underground mining. Ore production is now coming from both operations. By mid-1980, open-pit production will cease and all production will come from the undergroundmine.The underground mining method at the Ruttan Mine is sublevel open stoping with delayed backfilling. The orebody is divided along strike into a series of 27-m-long stopes and 15-m pillars, both 60 m high."

Jan 1, 1980

By K. L. Eastwood

The ISA PROCESSTM cathode plate is characterised by its copper coated suspension bar, coupled with a blade employing austenitic stainless steel alloy 316L. The blade material has become the mainstay of the technology and has been closely copied by competing cathode designs. Improvement to the cathode plate design remains a key area for research, and ongoing developments by Xstrata Technology's ISA PROCESSTM have recently been commercialised. Two such developments are the ISA Cathode BRTM and ISA 2000 AB Cathode. The ISA BR cathode is a lower resistance cathode that has proven to enhance operating efficiencies. The AB cathode was designed to improve stripping inefficiencies in the ISA 2000 technology. These developments have now had time to mature and their long term performance will be discussed. Rising material costs and the desire to extend the operating boundaries of the standard 316L cathode plate has triggered a number of significant advances. These involve the use of different stainless steels as alternatives in some operational situations. The technical aspects and results of commercial trials on this development will also be discussed in this paper.

Jan 1, 2007

By M. Askari, M. H. Parsa, S. Kashani-Nejad

Sarcheshmeh refractory consumption rate is about 7.5 - 8 kg/ton of the produced copper, which is almost three times higher than the other smelters practice. High destruction rate of tuyere zone refractory controls vessel productivity and operational lifetime. In this research with the aid of cold model and computational fluid dynamic (CFD), melt recirculation pattern and gas - liquid plume properties in the wide range of gas blowing conditions were studied. Results revealed that in addition to the well-known mechanical refractory destruction mechanism, fast tuyere zone refractory destruction could also be related to the cold bubble cluster formation near tuyere tips and introducing severe thermal shock to the refractory surface. Removing accretion and its strong bonds to the refractories around tuyere tip, causes refractory mechanical destruction and increases tuyere diameter. Increased tuyere diameter, in turn assists gas discharge in the bubbling regime. Air blowing in the bubbling regime result in the formation of big bubble clusters, bubble breakup and back attack occurrence which all found to have major impact on the refractory lifetime. Outcomes of this research, contributed to the plant converting management, blowing hardware and instrumentation improvement.

Jan 1, 2004

By Sammy Bansah, Komla Dzigbodi-Adjimah

Abstract-Ghana, a major West African gold-producing country, took a crucial step in 1986 to allow private participation in mining ventures that had hitherto been state controlled and starved of funds. This decision has led to a three-fold rise in gold production with substantial local and foreign capital once again flowing into exploration and mining projects. Though the rise in gold export is due primarily to increased production from large mines such as Ashanti Goldfields Corporation, Billiton Bogosu Gold, Tebrebie Goldfields and Ghana Australia Gold that work primary lode gold deposits on quartz veins and Banket conglomerates, a fair amount of gold comes from placer gold mining from which two new mines have been developed at Kwabeng and Bonte during the current gold boom. Also, placer gold mining is important locally because the lower capital outlay required for its development enables many entrepreneurs to operate small concessions and provide employment for a large pool of unskilled labor. Placer gold exploration and development in Ghana is labor-intensive. Pitting is the most used method although few employ the mechanized ("Banka") drilling. The advantages and disadvantages of the two approaches in the local setting are discussed. The gravel is normally sluiced and the gold recovered by amalgamation. The drawbacks to successful placer gold exploration in Ghana have been attributed to lapses in execution of exploration programs (Dzigbodi- Adjimah and Arhin, 1993; Dzigbodi-Adjimah and Gawu, 1994). However, the failure to recognize and set time frameworks and financial limitations for the various stages of placer gold exploration have spelt the doom of some projects. It is critical that the characteristics of the placer gold deposit be determined by efficient and cost effective means. A planned exploration supported by adequate flow of funds saves costs and leads to success. This article discusses the current Ghanaian situation and presents proposals from case studies for planning and budgeting placer gold exploration programs for use in similar settings.

Jan 1, 1995

By Sammy Bansah, Komla Dzigbodi-Adjimah

Ghana, a major West African gold-producing country, took a crucial step in 1986 to allow private participation in mining ventures that had hitherto been state controlled and starved of funds. This decision has led to a three-fold rise in gold production with substantial local and foreign capital once again flowing into exploration and mining projects. Though the rise in gold export is due primarily to increased production from large mines such as Ashanti Goldfields Corporation, Billiton Bogosu Gold, Tebrebie Goldfields and Ghana Australia Gold that work primary lode gold deposits on quartz veins and Banket conglomerates, a fair amount of gold comes from placer gold mining from which two new mines have been developed at Kwabeng and Bonte during the current gold boom. Also, placer gold mining is important locally because the lower capital outlay required for its development enables many entrepreneurs to operate small concessions and provide employment for a large pool of unskilled labor. Placer gold exploration and development in Ghana is labor-intensive. Pitting is the most used method although few employ the mechanized (“Banka”) drilling. The advantages and disadvantages of the two approaches in the local setting are discussed. The gravel is normally sluiced and the gold recovered by amalgamation. The drawbacks to successful placer gold exploration in Ghana have been attributed to lapses in execution of exploration programs (Dzigbodi-Adjimah and Arhin, 1993; Dzigbodi-Adjimah and Gawu, 1994). However, the failure to recognize and set time frameworks and financial limitations for the various stages of placer gold exploration have spelt the doom of some projects. It is critical that the characteristics of the placer gold deposit be determined by efficient and cost effective means. A planned exploration supported by adequate flow of funds saves costs and leads to success. This article discusses the current Ghanaian situation and presents proposals from case studies for planning and budgeting placer gold exploration pro-grams for use in similar settings.

Jan 1, 1995

By Gordon. I. M., J. Blackshaw

"The wet part of the Hollinger mill is housed in two buildings, the grinding plant and the treatment plant. In the grinding plant there are four 7xl5 ball mills which grind the ore to 60 per cent through 200 mesh. There is also one 7xl5 ball mill which grinds table concentrate to 9 5 per cent through 200 mesh.The primary classifier overflow is pumped to the treatment plant where it passes over shaking tables, producing a concentrate and a tail. The concentrate pulp is pumped to the grinding plant for secondary grinding. The secondary classifier overflow is pumped back to the treatment plant where it is thickened in two 40xl 5 tray thickeners and agitated in four 20x24 mechanical agitators arranged in series of two (with 2 spares).The table tail pulp is thickened in nine primary 40xl5 tray thickeners (with 2 spares). The thickened table tail pulp and the concentrate agitator discharge pulp are mixed and pumped to four rows of 15x45 pachuca agitators, arranged in series of five tanks.The pachuca discharge pulp is divided. The smaller part goes to two rows of 3-step decantation using 40xl5 tray thickeners (with 2 spare rows). The larger part goes to six 14xl6 drum filters. The repulped primary filter cake and the thickened pulp discharged from the decantation rows are fed to eight 14xl6 drum filters. The secondary filter cake is mixed with water and pumped to the tailing line."

Jan 1, 1968

By Robert S. G. Chapman, Kieran M. J. Downes

The Sulphide-Preview Lakes area is located 45 km northeast of La Ronge in northern Saskatchewan. It lies within the southern portion of the Proterozoic La Ronge Volcanic-Sedimentary Belt. Two styles of gold mineralization are present in the Sulphide Lake area , stratabound gold mineralization is intimately associated with a pyrite-pyrrhotite-arsenopyrite-bearing graphitic argillite unit within a sequence of intermediate to felsic volcaniclastics. Past operators established three mineralized zones along this horizon with combined reserves for two of the zones, of about 175,000 tons at 0.22 oz/ton Au. In the Preview Lake area , gold mineralization occurs in variably sheared gabbro/quartz diorite sills within a mixed sedimentary-felsic volcaniclastic sequence. Gold occurs with arsenopyrite, pyrite and minor chalcopyrite associated with quartz veins and stringers. A sulphidebearing graphitic argillite unit occurs in close proximity to the mineralized shears. Past operators delineated seven mineralized shear zones, two of which were drilltested. Average gold grades reported are in the 0.1 to 0.2 oz/ton range with erratic values up to 5.0 oz/ton.

Jan 1, 1986

By R. Saulters, M. Garshasb

The Transportable Moisture Limit (TML) is the copper concentrate moisture content beyond which liquefaction may occur during shipping. This study indicates that TML is a function of mineralogical characteristics of concentrate, which in turn may directly affect moisture retention properties. A comprehensive mineralogical and chemical analysis was conducted to determine the impact of composition and mineral content on concentrate’s TML. The analysis indicates that the high TML value is associated with particular minerals such as gypsum, swelling clay, muscovite and pyrite. Since higher TML values allow higher moisture contents for shipping, this property is desirable for concentrate inventory management and shipping flexibility. Scarcity of minerals that may increase TML contributes to limitations of shippable inventory. INTRODUCTION TML is the maximum moisture content of copper concentrate beyond which liquefaction may occur. Moisture content above the TML is considered a shipping hazard as it may result in loss of lives and cargo. The details of TML testing are given in ISO 12742:2007 (ISO 12742). In principle, TML is 90% of the Flow Moisture Point. The method of testing for Flow Moisture Point and TML is based on procedures that provide pulsations that simulate the cyclic force of ocean waves to determine moisture levels at which the onset of concentrate flow may occur. International Maritime Organization (IMO) provides guidelines for developing and approving TML testing and moisture determination in the context of its Moisture Management Plan (MMP) for shipment of copper concentrate cargoes (IMO 2013). The IMO regulations are specifically provided in MSC.1/Circ. 1454 “Guidelines for developing and approving procedures for sampling, testing and controlling the moisture content for solid bulk cargoes which may liquefy”. Since each port has its own operational characteristics, resource availability, peculiarities of governmental structure, and desired methods of interaction with the authorities, it is necessary to adopt the IMO guidelines to the local requirements. In order to establish a TML and MMP measurement system, it is required to implement and follow proper guidelines for the relevant procedures. For example, sampling procedures are developed in accordance of ISO 12743, “Copper, lead, zinc, and nickel concentrates – Sampling procedures for determination of metal and moisture content”. Moisture content of copper concentrate samples are determined in accordance with ISO 10251, “Copper, lead, zinc, and nickel concentrates – Determination of mass loss of bulk material on drying”. To assure strict adherence to the MMP procedures, the overall system needs to be integrated into the site QA/QC system, which would make them auditable and certified in accordance with standards such as ISO 9001, ISO 17025, and ISO 17020.

Jan 1, 2019

By R. K. Singhal

"On the mining side the Canadian oil sands industry has become proficient in excavation and disposal of ore and overburden. Nearly twenty years of mining experience is now behind this industry. While local improvements to existing mining systems and practices will continue, it is believed that some further gains in productivity can be achieved by selectively introducing new ideas from other mining and non-mining industries. This type of technology transfer is vital for over-all cost-effective technology enhancement of oil sands mining operations.Discussed in this paper are the issues of mining equipment, equipment sizing, microprocessor and computer based technol¬ogy as applied to mine-wide data management, automation and remote control and a projection of likely mining systems in the year 2000!This paper reviews the ""state-of-the-art"" in selected surface mining systems and attempts to evaluate the forthcoming technology and its application."

Jan 1, 1989

By Philippe Monier, Frank C. Basham

"This paper outlines the scope and applications of 'COALMOD', the British Columbia Ministry of Energy, Mines and Petroleum Resources' computerized financial simulation model for coal mining developments. After a description of the computer system and language of implementation, the logic and scope of current model sub-routines are presented. This is followed by a presentation of examples on the current applications of the model to public policy evaluation, including benefit-cost analysis, fiscal analysis and evaluation of the effects of public infrastructure investments made in support of mining projects.IntroductionThis presentation has been developed in response to a number of requests from coal mining companies and various public agencies who have indicated interest in understanding our application of contemporary analytical techniques to public policy in the coal sector. In particular, the subject of this paper is an explanation of COALMOD. a mnemonic given to a computerized, mine-specific, financial simulation model which is assisting the Government of British Columbia in evaluations of new coal projects, assessment of public sector investments made in support of these projects and. more generally, measurement of the financial effects of current or proposed government policies, and factors outside immediate government control such as coal prices and transportation costs."

Jan 1, 1981

By Maria Skyllas-Kazacos

The All-Vanadium Redox Flow Battery that was pioneered and has been developed at the University of New South Wales (UNSW) in Sydney since the mid-1980s is currently regarded as one of the most attractive energy storage systems for large-scale implementation in a wide range of grid-connected and offgrid applications. Several companies are now manufacturing and installing MW-scale VFBs in applications ranging from renewable energy storage, load-levelling, emergency back-up power and power arbitrage. The full-scale uptake of the VRB in commercial energy storage systems however, is heavily dependent on the availability and cost of vanadium used in the VRB electrolyte. Cost is also a function of purity requirements and although there is little scientific evidence on the effect of impurities on the VRB life and performance, VRB developers continue to demand high purity vanadium at considerable cost. This paper will provide a brief overview of the current understanding of electrolyte impurities on VRB performance together with an economic analysis of the impact of vanadium prices on overall VRB capital and levelised costs for a range of applications.

Jan 1, 2014

By J. C. Glandus, N. Tessier-Doyen, M. Huger

The Young's modulus of bi-phased model materials (vitreous matrix containing spherical alumina inclusions) have been determined by two complementary approaches: experimental and analytical. If the matrix and inclusions exhibit close coefficients of thermal expansion, the experimental results lie in the vicinity of the lower bound of the Hashin & Shtrikman's model. If there is a dilatometric disagreement between the components, untypical behaviors, similar to those obtained for a family of industrial refractory materials, were observed when the temperature varies.

Jan 1, 2004

By M. Rigaud, K. Sankaranarayanane, X. Zhou

The effect of varying fine alumina/ultra-fine alumina ratio on the Bingham to dilatancy transition in alumina based, self-flowing refractory castables has been studied in detail employing rheological tests and particle size distribution measurements. Analysis of flow resistance and torque viscosity values has shown that Bingham to dilatancy transition is strongly influenced by fine alumina/ultra-fine alumina ratio in the castable, as well as by the nature of ultra-fine alumina. The calculated values of rheological constants and the viscosity coefficient were found to increase at higher fine alumina/ultra-fine alumina ratios.

Jan 1, 2004

The control of carbon concentration in a counter current carbon absorption circuit is critical to optimise gold recovery. MINTEK has developed a carbon movement controller to address this potentially problematic area in gold extraction. This controller reduces operator interaction by automating carbon movement. Elution schedules are entered into the control system, which then moves the carbon through the circuit into the first adsorption tank until enough carbon is available for elution. This is done while maintaining the specified carbon profile within the circuit. MINTEK has also developed an online-carbonconcentration- meter to measure carbon concentration in pulp. The meter uses an ultrasonic measurement technique. Long term testing has shown the measurement to be robust and require minimal maintenance. Results from a gold mine in South Africa’s well known Witwatersrand gold producing area has shown a decrease in soluble gold loss between 30 - 50% when the controller was used.

Jan 1, 2014