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By Henri F. Letient

At the 25th Annual B.C. Mine Reclamation Symposium in September 2001, Huckleberry Mines Limited received the Jake MacDonald Reclamation Award for its exemplary mine waste management plan, conceived to prevent the onset of acid mine drainage and facilitate reclamation of the site. The mine is an excellent example of a total mine waste management plan, with all materials scheduled in detail for the life of the mine. The filling plan for the waste management facility takes into consideration the requirement for permanently flooding the potentially acid generating rock. From an acid generation point of view, the tailings fall in the zone of potentially acid generating material. To avoid long-term ARD concerns, it is planned to float pyrite out of the tailings towards the end of the mine life, thereby generating a non-acid generating tailings stream which will be used to cap the deposited mine waste. The pyrite-rich tailings will be discharged into the deeper portion of the impoundment. On closure, a permanent water cover will be maintained over the mine waste. Only beaches of non-acid generating tailings will remain exposed. Mining will be phased to also allow one of the pits to provide storage for potentially acid generating rock and to be flooded at the end of mine life.

May 1, 2002

During the hydrometallurgical processing of the major base metals Cu, Zn, Ni and Co, the presence of iron is normally a serious complication, and iron separation from the pay metals usually constitutes one of the main challenges for the metallurgist. There are many instances, however, where the presence of iron is beneficial, or is even required. Two cases are presented where iron is required during the processing of base metals. The first example deals with the use of ferric sulphate to oxidize sulphides, more particularly copper and zinc sulphides, under atmospheric conditions. The results presented confirm that ferric ion leaching is efficient, particularly when the oxidant is regenerated during the process. The second case is the use of iron to solubilise refractory cobalt oxide minerals; examples, including pilot plant results, are presented for various ores from Africa and Central America. In both cases, this paper reviews the basic concepts involved and provides details of their application.

Jan 1, 2006

By James F. A. Hatley

Northern Saskatchewan comprises an area of about 350 000 km2 and boasts some of the world's largest known high-grade uranium deposits. The successful mining of these deposits, however, can not be accomplished without overcoming technical challenges. Not only is the high grade of the uranium ore challenging, but mining methods need to be developed to deal with groundwater at very high pressures, and ground conditions that vary substantially from excellent to wholly unconsolidated clays and sand. This paper discusses the various mechanisms of inflows at the three of the Cameco Corporation Mines in Northern Saskatchewan. The risk of inflows is quantified in terms of unique challenges from hydrogeologic conditions, rockmass integrity, and uncertainty in geologic conditions. Mitigation strategies in case of an inflow are also briefly described. The paper concludes by addressing the impact of institutional rules (corporate standards) on minimizing, monitoring, and controlling the probability and/or impact of unexpected inflows.

Aug 1, 2010

By Thomas R. Larson

"Many concentrators use re-circulating “plant” water for dilution in their flotation circuits. However, if crusher dust suppressants, ball mill grinding aids, or even agitator bearing grease are introduced into this water, and the water itself is not subject to cleaning steps, then sufficient quantities of these chemicals may appear in the flotation cells and begin to impact the flotation separation. A bench flotation procedure has been coupled with statistical analysis in order to estimate the impact of small quantities of non-flotation chemicals on flotation performance.INTRODUCTIONCleveland Cliffs produces iron oxide pellets for blast furnace feed, and is developing the capability to produce ferrous metallic products to supply a wider customer base. Cliffs manages five North American iron mines, including the Wabush mine sites in Labrador and Quebec. Based on various characteristics of the ore bodies, the flow sheets of the five mines are diverse. For example, Hibbing Taconite uses magnetic separation alone as their primary upgrading method, but Northshore and Empire use magnetic separation followed by flotation, and Tilden uses flotation alone. Last but not least, the Wabush concentrator upgrades primarily with gravity and electrostatic separation techniques.At Northshore, concentrate from the magnetic separator circuit is fed to a reverse flotation circuit. By design, the magnetic separators operate at the highest possible recovery of magnetite, as the separator tails are discarded, and relatively high silica content was acceptable to Northshore’s customers. As the steel-making industry moved toward lower and lower slag volumes, the silica content in the magnetic separator concentrate became a problem. The flotation step was added in the late 1980s in order to decrease the silica assay of the magnetic separator concentrate to meet the current customer requirements. In this setting, the flotation feed stream contains very little silica that occurs as liberated quartz particles. As the degree of liberation of the flotation feed stream is then a limiting factor for silica removal, the online grind control then was linked to flotation in the overall plant control system so that grind can be adjusted to achieve improved liberation if necessary for the flotation process."

Jan 1, 2002

By W. Lin, Z. Z. Dong, C. L. Zhou, Y. C. Kuang

The inversion of rock mechanical properties based on well-logging data is a common method to drillbit selection in petroleum engineering, the basic principle of which is to use deep-well logging data and experimental regression model to calculate rock mechanical properties. The profile of rock mechanical properties can be established. According to the profile, the type of drillbit can be selected in different formations, which will improve the economic benefit of bit use indicators. Compressive strength of rock is one of the most important parameters. Conventional method to establish regression models of acoustic velocity and uniaxial compressive strength is on the basis of rock core sonic experiments and uniaxial compressive experiments. However, with the increase of deep drilling operation, triaxial compressive strength prediction model will play a more vital role in drillbit optimization selection in deep wells and improving ROP (Rate of Penetration). Triaxial compressive strength is an important parameter to evaluate the formation strength property. In this paper, to the sandstone commonly encountered in oil drilling, combined the rock mechanical experimental results with the changing porosity experimental results under confining pressure, a new interpretation model of triaxial compressive strength based on well logging data is proposed. Firstly, three types of sandstone samples are collected. Then measured components, uniaxial compressive strength, triaxial compressive strength and porosity. Experimental results show that: confining pressure has a significant influence on sandstone strength, with the increase of confining pressure, triaxial compressive strength increase; furthermore, the triaxial compressive strength of different porosity sandstones have different change rules when confining pressures changes; sandstone porosity decreases with the increase of confining pressure and it obeys logarithmic function. According to the results, regression models of sandstone, in-situ uniaxial compressive strength model and uniaxial compressive strength model under normal pressure are generated. Meanwhile, using well logging data in the acoustic velocity, density and gamma value can derive in-situ rock formations uniaxial compressive strength and in-situ porosity. Eventually, a new model established in this paper, containing in porosity, uniaxial compressive strength, lateral pressure and power exponent of regression, can predict triaxial compressive strength which will guide drillbit selection.

Jan 1, 2015

By Barun Gorain, Andy Stradling

"The traditional metallurgical scale-up techniques for flotation plants are based on lumped flotation rate constants, dimensionless hydrodynamic numbers and the use of safety factors. Once the plant has been designed, the flotation principles that govern scale-up play almost no role in the optimisation of the circuit to meet its metallurgical targets. This deficiency can potentially lead to a plant design incapable of meeting its targets, especially when circuits incorporate large flotation cells. This paper demonstrates the application of the k = PSbRf model in providing a suitable framework for flotation modelling, scale-up and circuit optimisation, thus presenting an integrated approach to the problem. Studies were conducted at Teck Cominco’s Red Dog concentrator to characterise cell hydrodynamics, gas dispersion properties, fioth flow behaviour, entrainment and ore floatability to obtain the key data necessary to develop a model for the flotation circuit. The findings of these studies are presented in this paper, which provide valuable insights into the modelling and optimisation of the Red Dog flotation circuit.INTRODUCTIONThe traditional methodology for flotation scale-up and plant design is based on the rule-of-thumb with safety factors, dimensionless hydrodynamic group similitude considerations, etc. With the recent trend towards larger flotation cells with volumes of 150 m3 and greater in concentrators, the problem of scale-up has become even more acute. The scale-up factors that may have been tolerated on smaller cells are not applicable to larger cells. The transportation of froth in these large cells adds further complexity to the problem. Arbiter et al. (1980) foresaw this problem and pointed out that if scale-up were attempted by rule-of-thumb and trial-and-error, then the probability of failure would increase with scale. This problem is confounded by the fact that the design and scale-up considerations used for a new flotation circuit play almost no role in optimisation of the circuit to meet its metallurgical target. This results in a plant design incapable of meeting its metallurgical targets. There have been several instances where new concentrators have required significant circuit modifications and additional capacity to achieve design targets."

Jan 1, 2002

By H. F. Letient, D. C. Johnson

At the 25th Annual B.C. Mine Reclamation Symposium in September 2001, Huckleberry Mines Limited received the Jake MacDonald Reclamation Award for its exemplary mine waste management plan, conceived to prevent the onset of acid rock drainage (ARD) and facilitate reclamation of the site. The mine is an excellent example of a total mine waste management plan, with all materials scheduled in detail for the life of the mine. The filling plan for the waste management facility takes into consideration the requirement for permanently flooding the potentially acid-generating rock. From an acid generation point of view, the tailings fall in the zone of potentially acid-generating material. To avoid long-term ARD concerns, it is planned to float pyrite out of the tailings toward the end of the mine life, thereby generating a non-potentially acid-generating tailings stream which will be used to cap the deposited mine waste. The pyrite-rich tailings will be discharged into the deeper portion of the impoundment. On closure, a permanent water cover will be maintained over the mine waste. Only beaches of non-potentially acid-generating tailings will remain exposed. Mining will be phased to also allow one of the pits to provide storage for potentially acid-generating rock and to be flooded at the end of mine life.

Jan 1, 2004

By C. Morlot, C. Auvray, E. Fourreau, J. Talandier

"During the excavation of underground galleries in a rock mass, reorganisation of the stress field around the site results in damage to the surrounding material. In the framework of research undertaken at the ANDRA underground laboratory in France, galleries have been excavated in a Callovo-Oxfordian argillite formation. The damage has manifest as a number of fracture systems in the adjacent rock. Observations have shown that fractures generated during excavation and storage exploitation are able to self-seal during re-saturation of the site in the post-closure stage. Although indirect evidence for argillite self-sealing has previously been reported, from experiments performed both in situ and on samples, no direct observations of self-sealing have yet been made.For the present study, we performed a range of self-sealing experiments using a newly-developed triaxial compression cell placed within a nano-CT scanner with a 10 µm resolution. The body of the compression cell is X-ray transparent, allowing sample healing to be monitored directly. The samples contained an artificial fracture that had been generated in the laboratory, into which a fluid was injected. The fractures were orientated either perpendicular or parallel to the plane of anisotropy of the material. Our initial results demonstrate that when fluid is injected perpendicular to the plane of anisotropy, the flow-rate has no apparent influence on the kinetics of fracture closure. Permeability varies significantly, from 2.10-14 to 2.10-18 m2 over 116 hours. Post-test observations of the fracture lips show swelling that appears to be orientated perpendicular to the fracture plane and therefore parallel to the plane of anisotropy. Initial results for an injection parallel to the plane of anisotropy suggest that, in this case, the rate of flow affects the kinetics of fracture closure. For a flow-rate of 0.25 ml/min, closure begins after around one minute. In contrast, for a rate of 0.05 ml/min, it is necessary to wait several minutes before partial sealing of the zone is observed. The reduction in permeability is again significant, from 2.10-15 to 4.10-18 m2 over 96 hours. After completion of the test, swelling was observed in elongated zones that lie parallel to the fracture plane and therefore to the plane of anisotropy."

Jan 1, 2015

By A. Rahimi

The smelting plant at Sarcheshmeh Copper complex commenced working with two reverbatory furnaces, four pierce smith converters, two anode furnace and one holding furnace having a known capacity of 420 metric tons of anodic copper according to the initial design in 1982 (1361 Iranian calendar). During the period from the commencement date up until now, the smelting plant has undergone changes for improvement and enhanced production by substituting holding furnace with another anode furnace, installing the fifth converter and utilizing oxyfuel burners on the ceiling of the reverberatory furnaces. According to the different operational processes in reverberatory, converter and anode furnaces different types of corrosion mechanisms and degradation can be observed in the refractories of copper smelting furnaces. In the case of reverberatory furnaces, the corrosion and degradation of refractories may be factors such as hot corrosion by melt, corrosion attack by the constituents of burning fuel, degradation of sidewalk exposed to mechanical stresses of the feed charge and the hydrostatic pressure exerted by the melt inside the furnace, all of which are due to the unique operational condition governing the reverberatory furnaces environment, i.e. burning fuel atmosphere, charge concentration and combination, furnace temperature, calm melt condition, etc. In the case of converter furnaces, the most likely corrosion and degradation of refractories may be due to the chemical reaction between the melt and degradation of tuyere zones due to sever movement of the melt and mechanical strikes of the punch rod. Also the most essential corrosion reaction occurs around the mouth of the converter because of the mechanical strikes by the cleaning device and thermal heat shock. Other parts inside the furnace are corroded due to the reactions between the fayalite slag and the furnace refractory. In anode furnaces the degradation mechanism is mostly related to the gaseous corrosion (penetration of natural gas or liquid gas inside the refractory structure due to the long period of reduction processes and refining stages. Finally another important factor responsible for destruction of refractories in these furnaces is the copper oxide slag together with the fume constituents of burning fuels.

Jan 1, 2004

By Mehmet F. Taner

"Abstract - "Les Mines Selbaie" is a large, generally low-grade, polymetallic (Zn, Cu, Ag, Au) "giant" volcanic-associated ore deposit in the Harricana-Turgeon belt, which is part of the northern Abitibi Subprovince of Quebec. Economically recoverable mineralization occurred in three zones: the A1 (open pit), A2, and B Zones (underground). The pre-mining resource was 54.9 Mt, including 8 Mt of sub-economic, locally silver-rich massive pyrite. In the Selbaie region, calc-alkaline andesitic volcanics form the "basement." The Brouillan Volcanic Complex formed within an islandarc setting on this regional basement. Evolution of this complex involved the formation of a felsic magma chamber and the development of a large caldera structure over the Brouillan batholith. Second- order linear and sub-parallel faults and rifts developed as a result of back-arc rifting/extension. The edges of these rifts were feeders for linear felsic volcanism (similar to fissural volcanism). During felsic volcanism, the feeder zones acted as conduits for hydrothermal fluids with associated pervasive potassic alteration. The alteration is characterized both vertically and laterally by well-defined quartz, sericite, K-feldspar and/or, locally, biotite halos, to produce a mushroom-shaped morphology. This K-feldspar alteration is not common in most other volcanic-associated ore deposits. Mafic dikes cut all of the geological units and appear to occupy earlier synvolcanic structures. Regional greenschist- assemblage metamorphism and pervasive deformation affect all units. Thrust faults moved part of the Brouillan batholith and basement units over the Mine Sequence. Although there is no relationship between the earlier mineralizing events and these late thrust faults, the thrust faults probably played an important role in location of ore lenses. Three types of mineralization are present: 1) copper-rich veins and hydraulic breccias; 2) disseminated and stringer, low-grade and high volume zinc-copper mineralization; and 3) finely laminated, massive, locally silver-rich pyrite mineralization within structural basins. At the bottom of these basins and at the contact of welded acid tuff (WAT) units, massive pyrite zones are locally enriched in zinc, and contain the possible vestiges of black smoker-like material. The ore metals were probably derived from leached basement andesitic volcanics in a hydrothermal system powered by one or more heat sources within the Brouillan Volcanic Complex. The Selbaie deposits are mainly characterized by: (1) the presence of small volcano-tectonic subsidence basins, which host chemical sediments and volcaniclastic materials; (2) pervasive potassic alteration; (3) locally high-grade silver mineralization (up to 1-2 kg/t Ag); and (4) the presence of random zones of Pb mineralization. The Selbaie deposits can be closely compared with the copper-rich Murgul deposits, which belong to the eastern Pontides metallogenetic province in Turkey. If conventional classification criteria for the volcanogenic massive sulfide deposits (e.g., Noranda, Mattabi types, and recent subsea floor deposits) are taken into account, the Selbaie deposits still exhibit many differences in terms of alteration assemblages, physical volcanology and some styles of mineralization (low-grade and large volume). Consequently, the "Selbaie" deposits belong to a new sub-type of volcanic-associated sulfide deposit, which may be used in future exploration programs."

Jan 1, 2000

By P. C. Lightfoot, J. M. Duke, A. J. Naldrett

"The segregation of magmatic sulphides from mafic and ultramafic silicate magmas, in many circumstances, leaves the magma with a lower-than-normal Ni/MgO ratio, which is characteristic of both lavas erupted from the magma chamber and olivine crystallizing within it. Two end members of the segregation process are discussed; i) batch segregation and ii) fractional segregation.In the former, the critical factor is the magma/sulphide ratio. Computer modelling suggests that where this ratio has been less than 1000, the magma will be recognizable as anomalously low in Ni, due to sulphide segregation, and thus a good target for exploration. In fractional segregation, the critical factors are the proportion of sulphide to silicate being segregated and the degree of fractionation.Samples believed to represent the liquid portion of komatiitic lava f lows from a series of unmineralized sequences in the Abitibi greenstone belt, Canada. Belingwe belt, Zimbabwe, and Barberton Mountainland, South Africa coincide with the sulphide-free fractionation model. They are in marked contrast to samples from the ore-bearing districts of Kambalda and Scotia. Western Australia in which distinct Ni depletion, corresponding to fractionation of olivine plus sulphide in a ratio of between 100 and 200:1 is recognizable. Ni-depleted olivines also mark the sulphide-bearing Dumont intrusion of the Abitibi belt.The Moxie intrusion of northern Maine has distinctly Nidepleted olivines, as does the nearby and petrologically related Katahdin body. In both of these intrusions, the composition of the olivine allows reasonable predictions to be made of the Ni tenors of sulphide showings within them. At Katahdin, the Ni depletion is so widespread that little hope is help out for the presence of economic concentrations of sulphide. At Moxie. the olivine compositions suggest that the best chance of economic sulphides lies in the southern lobe of the intrusion.Ni-depleted olivines also characterize certain rock units within intrusions of the Insizwa complex, Transkei, Southern Africa. Many millions of tonnes of Ni have apparently been removed by sulphides from these rock units, many more than are contained within the single mineralized occurrence so far identified at Waterfall Gorge."

Jan 1, 1984

By Antonius Prayoga

PT Smelting adopted the Mitsubishi Continuous Technology for its copper smelter plant which has been operating since 1998. Through a series of expansion projects, the plant annual production capacity increased gradually from 200,000 to 300,000 tons of copper. There were no significant modifications for the smelter to reach the 50% additional capacity. It was mostly achieved by intensifying the operation of the furnaces by increasing the oxygen content in the furnaces blowing air. Intensive smelting furnace operation caused shorter campaign life of some furnace refractory, especially the melt zone wall on furnace outlet. During each furnace relining, which is done once every two years, severe wall erosion was found. The worst condition occurred in 2007 when the smelting furnace experienced a melt leak through the eroded wall beneath the bath-line coolers. During the 2008 furnace relining, a modification was performed by installing vertical coolers behind the melt zone wall. Additional vertical coolers were installed during the 2012 furnace relining to extend the coverage area. The modification improved melt zone wall integrity significantly by keeping them safely within the two year campaign life. Recently a modeling study was done to estimate the influences of molten waves on furnace wall erosion. The aim of the study was to predict the impact of blowing parameters, such as blowing air velocity, on the melt wave character and wall erosion.

Jan 1, 2015

By H. R. Butler

"The Ontario Division of Inca Metals Company, a Unit of Inca Limited, operates eleven mines, four mills, three refineries, one smelter and one iron ore recovery plant. All but one mine, mill and refinery are located within a fifty kilometer radius of Sudbury, Ontario. A mine-mill complex is located some 100 kilometers west of Thunder Bay on the shore of Lake Shebandowan and a nickel refinery at Port Colborne.During the past 10 years the use of recycled water in our milling operations has increased to more than 95% at each mill. This high degree of water reuse has reduced the (a) need for fresh water and (b) the contaminant level of the downstream aquatic environment. The aggregating of effluents in a common receptor provides a process water having a consistent quality thereby minimizing upsets in mill metallurgy while concurrently improving the operating economies and the downstream aquatic environment."

Jan 1, 1980

By Gary Raymond

The Similkameen Division of Newmont Mines Limited operates a low-grade open-pit copper mine in southern British Columbia. The copper mineralization is extremely erratic.As a result, over seven years of operation, ore control methods have evolved from standard flagging based on blast-hole assays, through an in-pit grab sampling system, to the present method of mining to computer-determined ore-waste boundaries based on geostatistics. These improved ore control methods have resulted in a gain of at least 25% on ore tonnage miffed, at the same grade as obtained using earlier techniques. At the same time, geostatistical ore reserve estimates are now within 7% of milled ore tonnage and grade on a yearly basis, whereas the original polygon ore reserves under-estimated mineable ore tonnage by 15% to 45% and over-estimated grade by about 20%. The author discusses why traditional ore estimation methods give poor results in erratically mineralized orebodies and describes the geostatistical approach to the problem.

Jan 1, 1979

By Scott Hopkins

Simulation tools are preferred for evaluating complex systems due to its ability to mimic reality and quickly evaluate many different what-if scenarios and find global solutions. A simulation model is capable of representing variable and dynamic disturbances that are typically encountered in day-to-day operations; this is where spreadsheet models or linear programs fall short because they cannot account for the dynamic behavior and relationships. The simulation model used for this work was developed by Xstrata-Nickel (previously Falconbridge). The simulation tool is very flexible and can be used to simulate different mining and development methods. The scope of the modeling included production mining, geology, equipment fleets, equipment maintenance and random failures, manpower, shift schedules, and cycle activity times. A case overview of the 170 Orebody will be presented along with the challenges associated with data collection for the model inputs. Results and lessons learned will also be discussed.

May 1, 2008

By D. Bois, P. Poirier, B. Bussière

Environmental desulphurization is an attractive alternative for the management of acid generating tailings. Bulk sulphide flotation is the most commonly used method to produce desulphurized tailings, as shown from many previous works. This process can reduce the volume of problematic tailings to manage by making a sulphide fraction concentrate. The desulphurized tailings can then be used as construction material for an engineered cover to prevent acid mine drainage. In this paper, the results from different laboratory and pilot scale flotation tests are presented. These results confirm that low sulphide non-acid generating tailings can be produced by froth flotation. It is also demonstrated that sulphide concentrates obtained from desulphurization mixed with the appropriate binders can be used as feed material for paste backfill. From previous work on the evaluation of operating and capital costs of the desulphurization process for different ore types, the use of desulphurization as a tailings management approach was studied for several scenarios. The desulphurization process was then compared with other technologies (underwater disposal, engineered soil cover) currently used to prevent acidic drainage (AD) for a new mining operation. Results show that partial or total desulphurization are technically and economically viable options to manage tailings during mine operation. Mine waste managers should consider desulphurization as an efficient technology.

Jan 1, 2005

By Robert B. Wickham

"American Barrick has always balanced its aggressive operating approach with a conservative financial strategy. In fact, what enables their mining team to pursue such aggressive plans with confidence is the conservative financial strategy adhered to by the company. These policies are built on a prudent mix of gold linked financings, equity and gold price hedging.This paper outlines these policies and focusses in particular on American Barrick's gold price hedging program.IntroductionThe company's balance sheet at the end of 1990 clearly shows the wisdom of its conservative policies. Total assets have grown to over US$1 billion; cash has grown to US$312 million and shareholders' equity to US$645 million. All amounts included in this paper are quoted in U.S. dollars. Increased gold production and an effective gold price hedging program also combined to produce record income from operations, earnings and cash flow in 1990.The first half of 1991 is also indicative of the benefits of the company's conservative financial policies. Increasing production, together with its comprehensive gold hedging program, has generated increased earnings, even in a period of falling gold prices.All year-over-year numbers for the first six months are up. Gold production was 36% higher; earnings of $40.2 million $ 0.30 per share - were 46% higher than 1990.Barricks revenue continued to increase despite gold prices remaining unchanged during 1990. Barrick's hedging policy protects the company from falling gold prices on the basis that the upside looks after itself. Their hedging program - including various goldlinked fmancings - enabled Barrick to realize an average price of $437 per ounce of gold sold in 1990, compared with the Comex average gold price for the year of $384 per ounce."

Jan 1, 1991

By Fidelis T. Suorineni

Rapid drifting enables quicker access to orebodies, higher production rates and a resultant reduction in production cost. The Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO) funded by the Canadian Mining Industry Research Organization (CAMIRO) has developed a methodology for safe rapid drift development within the underground metalliferrous mining industry in Canada According to industry survey, about 36% of drift development cycle time is spent on support installation. MIRARCO has developed a methodology for safe rapid drift development based on minimizing time spent on support installation. The methodology includes a critical review of the rockmass classification systems, examination of current support practices in the mining industry and civil tunneling, review of rapid drift development practice in South Africa, introduction of risk hazard procedures to account for material property variability and the development of a WIZARD as a quick decision-making tool for the implementation of the procedures. A comprehensive field data collection procedure was put in place and data collected from various mines to verify and calibrate the support selection rationale. The findings of the research programme resulted in the development of an improved rockmass classification system and showed that construction effects have drastic influence on support levels but is often not accounted for in assessing support levels. Stress effects and structurally controlled failures are the other important factors to take into account in rapid drift development. Three support classes were established for safe rapid drift development as No Systematic Support, Light Support and Strong Support. The support levels took into account cost, rate of installation and safety based on compatibility with ground characteristics. This paper describes the methodology for safe rapid drifting within the underground metalliferrous mining industry in Canada and highlights the key issues and major drivers behind their continued development at the Geomechanics Research Centre within MIRARCO.

May 1, 2004

By J. Bruce See

INTRODUCTION This symposium at Cu 2019 has been organised to honour and celebrate the career and achievements of Dr Phillip John Mackey, an internationally recognised expert in the production of non-ferrous metals, especially copper and nickel smelting and refining. Phillip was born in Epping, a suburb of Sydney, New South Wales, Australia on 19 April 1941 and is one of 4 children of Gilbert and Philomena (nee Bartlett) Mackey. After completing Primary School in Epping, he attended Marist Brothers High School in Eastwood, Sydney and graduated in 1957 as the Dux of the School. Phillip’s father, being on the staff of the Sydney Technical College, in Ultimo, Sydney had the opportunity in the early 1950s to meet the late Professor Sir Rupert Myers, Foundation Professor of the School of Metallurgy at the New South Wales University of Technology (later called the University of New South Wales or UNSW). Gilbert Mackey was impressed by the new young Professor of Metallurgy and encouraged his son to study metallurgy - at the time an expanding industry in post-war Australia. EDUCATION AT THE UNIVERSITY OF NEW SOUTH WALES Phillip commenced at UNSW in 1958, graduating with honours in 1963. His undergraduate education and training included a few years of part-time study while working at British Motor Corporation on sheet metal forming of car bodies. At University Phillip developed his talent for teamwork. He was a contributing writer to the University newspaper, Secretary of the UNSW Students’ Union and was active in the UNSW Metallurgical Society and co-editor in 1963 of “Metallurgical Review,” the annual journal of the UNSW Metallurgical Society. His diverse interests and curiosity about the world around him were likely nourished while at University. Upon completing his Bachelor’s degree, Phillip was awarded a Commonwealth of Australia Postgraduate Research Scholarship. He began his PhD in 1964 on the thesis topic “Studies in Heat Transfer between Dispersed Liquid Metals and Gaseous Atmospheres” working under the supervision of then Associate Professor Noel Warner, an outstanding Professor at the University. Professor Warner is now an Emeritus Professor at the University of Birmingham and is internationally respected for his pioneering theoretical and practical work on established and innovative smelting processes.

Jan 1, 2019

By E. P. Cadwell

"Throughout the years Cyanamid has been a supplier of cyanide and a supplier of information to the mining industry. In general, the knowledge of mineralogy is greatly overlooked. Mineral deposits in the Western hemisphere have been exceedingly rich in the past but now they are becoming poorer. In other words, we will have to use our talents to the utmost to extract the precious metals and base metals from these ores. Modifications of some of the mineralogical equipment displayed here belong in the mill.Cyanidation of copper has been one of the main projects in our labs in recent years. De-rimming or de-filming of copper in order to upgrade copper concentrate was the main aspect investigated. A study was made as to how wide spread was the filming of secondary copper on pyrite, and to what extent it affected the copper industry. It was very wide.Often there is no conception as to what the minerals are. One open pit copper producer with a chalcopyrite ore was producing a copper concentrate with a 5% copper value whereas chalcopyrite contains 35% copper. They used primary and secondary grinding and a regrinding section. The ore contained about 8 parts chalcopyrite to one part of other copper minerals. In tests, a 3 1/ 2% copper rougher concentrate, cleaned without regrinding but conditioned with cyanide for a low contact time of 30 seconds produced a 30% copper concentrate with 90% recovery by removal of the film. It was of utmost importance that some quantitative mineralogical analysis be made before flow sheet changes were made. Every man should be trained to do his own microscopic examination in order to get quick answers. The fundamental thing in all mineral dressing is to first of all know the minerals and the mineral associations."

Jan 1, 1964