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By W. W. Muir

"The Baker Mine used a 100-ton per day conventional cyanide leach mill located in northern British Columbia. A production decision was made in early 1980 and the mill was on fine in April 1981.Ore reserves had been estimated at 100,000 Ions averaging 0.9 oz gold per ton and 18 oz silver per ton . Mineralization consists of electrum (Au/Ag) and acanthite (Ag2S).This paper will review plant design and focus on some problems associated with start-up and early operation with the intention of assisting other mine operators by indicating potential problem areas.IntroductionThis paper will discuss operating strategies employed at Baker which improved over-all mill performance. Also included are some ideas which could be steps toward a more efficient operation in a similar setting.Actual dore production by mine life was 37,606 oz gold and 742,117 oz silver.Figure 1 illustrates the relative stability attained over the mine life. Metal recoveries for gold and silver were 92% and 85% respectively.Safety at Baker was of prime importance because of its remote location. Baker received the Mine Safety Association ""Small Mines Award "" in two of its three operating years. At shutdown in late 1983 the mill had operated for over 850 days without a lost-time accident."

Jan 1, 1985

By A. Sacit Saydam

"Induced polarization/resistivity and magnetometer surveys have been carried out over the Casmo molybdenite deposit in mountainous terrain of northern British Columbia. Molybdenite occurs in quartz-bearing fractures with or without pyrite along a zone of hydrothermal alteration and intense fracturing, believed to be a northerly dipping fault zone, within medium-grained equigranular and porphyritic quartz monzonite.The molybdenite-bearing zone is characterized by a significant resistivity low, a metal factor high and a subtle IP low flanked by highs outside the mineralized area. Magnetic trends, indicated by a magnetometer survey, generally parallel the zone and strike direction of the different intrusive phases, and have been helpful in delineating contacts and faults in the area.IntroductionThe Casmo molybdenite deposit is 6 km southwest of the asbestos mining town of Cassiar in northern British Columbia, at an elevation of 1,550 metres. Molybdenite was first discovered during the early 1950s and the first important exploration work was done in 1964. Between 1964 and 1971, about 25,000 feet of drilling was done by various operators, as a result of which 33.7 million tons of molybdenite ore was drill indicated at a grade of 0.123%. In 1979, Shell Canada Resources entered into an option agreement with the former operator, New Jersey Zinc Corporation. Shell completed 27,000 feet of diamond drilling between 1979 and 1980 and ha s reported 75 million tonnes of drill-indicated ore with an average grade of 0.13% MoS2• This paper is a case history of IP I resistivity and magnetometer surveys done over the Casmo deposit during 1979 and 1980."

Jan 1, 1983

By Douglas A. Sloan

"Recently, a number of major mining companies seemed unable to find a president from within the industry, and were searching outside the industry. From this, one could conclude that managers within the industry are either not being prepared or are not preparing themselves for presidential responsibility. Opinions were sought from a number of senior executives, to attempt to define the skills a prospective president should acquire and what actions a company could take or that a prospective president could take to acquire these skills.This paper contains summaries of the opinions obtained, along with the author's comments. The paper also describes the actions some companies are taking and the actions that an aspiring president can take to prepare himself for corporate management.IntroductionA manager is promoted up the management ladder when the manager's superiors believe that he is capable of handling a more senior position. Normally, the manager acquires this credibility by outstanding performance in his current management post, whether it be in a junior management (supervisory) or in a vice-presidential capacity.In most instances, the skills required for promotion can be acquired in the current position or, at worst, the abilities exhibited in a candidate's current role will convince his superiors that the necessary expertise for the more senior position can be acquired on-the-job. This is particularly the case when the new skills are felt to be an extrapolation of the old skills.However, in the case of appointment to presidential rank, there appears to be a need for new expertise which often is not acquired in normal management progression or, at least, boards of directors of some mining companies seem to believe this to be the case. The objective of this paper is to attempt to define the new skills that should be acquired by a manager who aspires to be the president, and to describe what actions might be taken by him to acquire them."

Jan 1, 1982

By Robert B. Parsons

"The Canadian Exploration Incentive Program (CEIP), which was announced by the federal government on May 3, 1988, promises to maintain the viability of flow-through shares as a financing mechanism which has proven to be so crucial to the health of the junior exploration sector. This month, Tax Notes examines, the main features of CEIP, which will come into play on January J, 1989. IntroductionOn May 3,1988, the Honourable Marcel Masse, Minister of Energy Mines & Resources, and the Honourable Gerald Merrithew, Minister of State (Forestry and Mines) announced the Canadian Exploration Incentive Program (CEIP). Under CEIP, the federal government will make cash payments to eligible applicants equal to 30% of eligible exploration expenses. CEIP payments will be available with respect to both mineral, and oil and gas, exploration. In essence, the program will replace the ""mining exploration depletion allowance"" (MEDA) presently applicable to mineral exploration, and the Canadian Exploration and Development Incentive Program (CEDIP) which is presently available to the oil and gas exploration sector.This paper discusses briefly the main features of CEIP insofar as the program will affect mineral exploration. The comments herein are based on the Canadian Exploration Incentive Program Act which received Royal Assent on July 21, 1988, and on a discussion paper which was released by EM&R in May 1988. The bulk of the rules relating to the program will be in the form of regulations which have yet to be finalized. It is understood that EM&R would like to have the regulations in force by October I, 1988, when the oil and gas portion of CEIP becomes effective. (The rules relating to mineral exploration will become effective January I, 1989)."

Jan 1, 1988

By L. A. Wolff

"Second only to profitability (but not always), productivity is the most sought after measurement for any operation. Whether it is in mining, manufacturing, construction, etc. managers always strive to know how productive various plants are. Even the Federal Government publishes, on a monthly basis, the nation's factory productivity.Just what is productivity and how is it measured? This is an important topic that needs definition. There could be as many definitions as there are people who use it. In the mining industry, the problems of defining productivity would be analogous to the definition of equipment availability. Each mine uses its own definition to suit its needs. Webster's Dictionary primary definition for productivity is ""the quality or state of being productive,"" with productive defined as ""yielding or furnishing results"". This is a definition open to a broad spectrum of interpretation. A discussion of how productivity is currently used in the mining industry and an introduction to a potentially different approach to its measurement and meaning is outlined in this paper.Defining ProductivityTypically, mining companies track several productivity measurements. These are partial measurements and can include the following: tons per specific equipment class per hour, tons per man-hour, and tons per shift. None of these, however, track the over -all performance of an operation, that is, a unit of output per unit of input.For a mining operation, output can be defined as the ore for mill processing. Input includes the required components of production to get to the first step of processing.The Wesbter's Dictionary definition exposes a major fault with the popular conception of productivity. The critical issue of accountability is not addressed. Anyone can produce, but how effectively and efficiently are resources used? Quantifying an inclusive measurement is difficult. Statistics referring to an increase in productivity are often published. For example, the statement, ""gold productivity has increased by 10%"" has many potentially dangerous interpretations. One must ask, what does this statistic really mean? Did gold companies produce 10%” more gold? Were less manpower or equipment required to produce an equivalent amount of gold? Did ore grades increase resulting in more ounces of gold produced, etc. Obviously, production and productivity can have similar implied applications and meanings, but also two different, distinct meanings.To mitigate a problem like this, a standard needs to be developed within the mining industry. Because of varying ore grade, changing waste to ore ratios, different mining methods, etc. all of which have a direct impact on mining, development of a standard is difficult. Kendrick(1) discusses the use of Total Factor Productivity as a productivity measurement. Summarized, the total factor productivity measure is an indication of the change in efficiency in the use of basic labour and capital factors associated with an operation.This measurement has little meaning when calculated at a given point in time. It should be an on-going calculation, tracking an operation over a period of time, to evaluate trends. These trends can be used to determine if an operation's productivity is what it should be, and alert management to potential problems before they become major and adversely affect an operation."

Jan 1, 1990

"The last thirty years have seen enormous changes in all aspects of the gold industry, from the technologies of mining and extracting gold to the role it has played in the fiscal policies of nations. In this time, the market price of gold has increased ten fold and mine production has more than doubled. However, the cost of mining and extracting gold has also increased exponentially, and the industry has struggled with declining ore grades and increasingly refractory ore bodies.With the major economic powers of the world shrugging off the uncertainties of the post cold war era and moving into a period of unprecedented political stability, economic growth and low inflation, gold is also losing its lustre as a hedge against inflation and a backing for national currencies. Consequently, countries that had accumulated and hoarded gold for decades are now disposing of these non-performing assets, resulting in major swings in supply of the metal. Fortunately, this has coincided with the end of communism in many parts of the world and a tentative move to free market economies in most of the developing nations. As a result, people are becoming wealthier, and this is creating more demand for gold, principally in the form of jewelry.On balance, the shift in the role of gold, from one in which a significant portion of new gold production lay dormant in bank vaults as insurance against political or fiscal instability, to one in which most new gold is now freely traded as an industrial commodity, responding to normal market forces of supply and demand, has had a negative impact on the price of gold over the last fifteen years. In that time, the gold price has declined from a peak of $850/oz in 1980 to an average price of about $400 through the rest of the l 980's, to a price of -$320/oz today (1997). In large measure, this has been due to the enormous inventory of gold metal that was held by central government banks in vaults around the world, and which has been dumped on the market as soon as the price has started to trend upwards. Even today, after ten years of fairly steady selling by central banks, about 3 0, 000 tons of gold (or -8 years' supply at the present rate of consumption) is still retained in vaults (Murray et al., 1997).The downward pressure on the price of gold has created exciting opportunities for the development and implementation of new technology. Increasing the efficiency of gold recovery from more and more refractory ore bodies, whilst at the same time lowering production costs, have become critical to survival in this industry. These challenges have been met by the development and implementation of new technologies such as heap leaching, carbon in pulp, resin in pulp and the sulphide ore pre-treatment process of pressure leaching, bacterial leaching and fluid bed roasting. For an industry that saw very little technological change in the first seventy years of the twentieth century, the pace of change over the last thirty years must have seemed bewildering at times."

Jan 1, 1998

By D. A. Mackie, J. E. Rider

"Good belt conveyor design is the most often neglected detail in the engineering of a plant. This results in downtime from spills or jams and premature failure of equipment components. Careful layout and component selection will result in better operation, a cleaner plant and therefore lower maintenance costs.IntroductionDespite the availability of many excellent sources of data on conveyor design, such as the Conveyor Equipment Manufacturers' Association (CEMA) Manual, ""Belt Convyors for Bulk Materials"" , there continues to be repetitive errors made in design. Why? Certainly, there is no substitute for experience, but largely, classical errors in belt conveyor design is rather elementary and so the temptation to have the work done by relatively inexperienced designers is great. What that does is develop "" experienced"" designers who become incompetent through no fault of their own. It is hoped that this paper will supplement available design data, help those who are "" put into"" a design situation to better cope with their predicament, and ease the lives of plant maintenance personnel."

Jan 1, 1990

By D. Mraz

"Under high pressure in a deep potash mine, the salt rock behaves in accordance with the concept of a generalized, perfectly plastic substance. The paper presents the evidence of this behaviour and engineering concepts f or room-and-pillar design. IntroductionThe mining and refining facilities at International Minerals &. Chemical Corporation (Canada) Limited are located near Esterhaz y at the southeastern edge of the Saskatchewan evaporites. Ore extraction began in 1962 and at the present time the annual mining capacity is in excess of eleven million tons of potash ore.A generalized geological section is shown in Figure I. The mining horizon is overlay in by 100 feet of rock salt followed by a thin bed of competent dry shale. The strata in the next 1,500 feet are generally competent and locally water bearing. The Blairmore formation contains strata of water-bearing unconsolidated sand. Below the mining horizon, rock salt is interbedded with anhydrite bands.The 8-foot mining bed is distinguished mainly by grade and clay content, as there is no definite bed boundary. The chief mineral s are halite, sylvite and, in some cases, carnallite, with up to 2 per cent disseminated clay. The ore is coarse grained, with crystals averaging one-half to three-quarters inch across.The major mining problem is related to the fact that the Dawson Bay formation, overlying the evaporites, contains areas and channels that are highly porous and permeable and are filled with unsaturated brine under high pressure. Consequently, all mining areas, with no exception, must be so designed that the overburden salt stratum remain s competently supported for the duration of the mine .This paper outlines a successful engineering method of determining the stability of the pillar s and designing a stable room -and-pillar mining system."

Jan 1, 1980

By G. E. Agar, J. J. Barrett

"Traditionally, batch bench-scale flotation tests have been used for evaluating flotation reagents by comparing the results of tests done with various additions of the reagent in question. Usually, comparisons are made of the concentrate grade and recovery or some figure of merit involving an empirical combination of both. In some cases, statistical methods have been used to make the comparison and even to identify optimal combinations of reagents.None of the preceding technology utilizes the fact that flotation separations can be described by relatively simple kinetic equations that will serve not only to quantitatively describe the influence of a reagent, but will also aid in designing an optimal separation procedure. Examples of the use of a first-order rate equation for evaluating the impact of a reagent addition and for optimizing the reagent addition are given.IntroductionThe classical method of evaluating flotation reagents is to conduct batch bench-scale tests while varying one factor at a time. Some of the shortcomings of this technique have been pointed out and statistical design and evaluation of experiments has been advocated. Although the statistical approach is superior to the one-at-a-time method, it still is dependent on the results of a batch test conducted for a specific duration.That flotation is primarily a rate process than can be described by a first-order rate equation has been recognized for a long time, but the application of this knowledge to the evaluation of reagents has received little attention. In this work, it is demonstrated how the parameters of the first-order rate equation can be utilized to evaluate the influence of reagents on flotation."

Jan 1, 1983

By R. A. Walker, G. Scheltgen, T. Javorsky, G. Blackwell

"Recent engineering advances in open pit rock mechanics have resulted in improved pit wall slope design and improved operating procedures in the event of a major wall instability. At the other end of the spectrum, on the scale of single bench failures, considerable discretion is left to the mine operators as to how potential problems are handled. The usual alternatives are either to operate with caution beneath potential hazards, or try to bring the unstable rock down. In specific cases it may be advantageous to attempt to stabilize rock structures for reasons of access and operating safety.A t the Brenda Mines open pit a prominent structure on the north wall had caused recurring bench-scale wedge failures when exposed on each mining level. In spite of operating precautions a shovel was hit by a rockfall causing significant damage. The first section of this paper describes the investigative, design, and stabilization methods which permitted subsequent mining beneath the structure to proceed without incident. Emphasis is placed on the personnel and equipment resources available at the mine site which were used to minimize costs and which would be available at most operating mines.The second section describes an ongoing research project that utilizes radio telemetry to transmit slope monitoring data. As part of this project the wedge structure was instrumented so that it could be continuously monitored with the aid of a computer. The application demonstrated the potential of 'micro- chip' technology to remote data collection and processing as related to rock structure monitoring, slope stability and safety."

Jan 1, 1989

By J. L. Dion

"A study of the techniques to integrally cast copper tubes in copper tuyeres for use in blast furnaces has been carried out. The work has been performed in support of current efforts to produce two-compartment tuyeres having improved water-cooling capacity. A test pattern corresponding to a vertical section of a two-compartment tuyere, and including a cast-in-place copper tube, was used to investigate such variables as tube preparation, tube coolant, pouring temperature, pouring rate and gating design. Successful castings, either with a good metalfurgical bond or good intimate contact between the tube and the casting, were produced, with all combinations of gating system and position of the tube tried. However, the pouring temperature, the pouring rate and the effectiveness of the coolant are interrelated and must be controlled to produce a good metallurgical bond.IntroductionAs part of its contribution to, and in collaboration with, the Copper Casting for the Steel Industry Committee, CANMET has undertaken research into the methods and techniques needed for the integral casting of copper tubes into high-conductivity copper castings.The objective was to produce two-compartment copper blast furnace tuyeres in which the water-cooled nose compartment consists of a copper tube metallurgically bonded to the wall of the high-conductivity copper casting. This design, developed in the UK, has demonstrated a much extended service life with attendant economies; unscheduled shutdown of blast furnaces due to tuyere failure is a significant problem in the steel industry. The Canadian steel industry believes that this design will replace the currently used single-compartment tuyere in blast furnaces within a few years.The technology to produce these tuyeres does not exist in Canada. One of the main features is the inclusion of a smooth-walled cooling channel in the nose, which permits high velocity cooling water to be employed. A second compartment acts as a reservoir backup, should failure in the nose occur. This would allow continued use of the tuyere for a period of time, permitting a scheduled shutdown for repair s. To assist the Canadian producers of tuyeres to maintain their market, and the Canadian steel industry to have a reliable domestic supply, it is important that the necessary technology for the production of two-compartment tuyeres be developed and transferred to industry."

Jan 1, 1982

By Dennis V. Woods, J. Duncan Crone

"In order to determine its capabilities and to aid in the interpretation of fie ld results, a scale model study and field tests were carried out on the Crone borehole pulse electromagnetic (PEM) system. The model results indicate that if a borehole passes in the vicinity of a tabular conductive body, the system will not only detect the presence of the body, but will also return information as to its conductivity-thickness product, size, altitude and position.The effect of variation of these electromagnetic and geometric factors on the shape of the response curve from a borehole PEM survey is displayed by a number of suites of scale-model response curves. These model curves can be used directly as type curves in the interpretation of field results. Field tests of a prototype PEM system provide a check on the scale-model results and also summarize the procedure of interpreting field data using the model type curves.The borehole pulse EM system can be effectively used as a follow-up geophysical instrument for locating and delineating known conductive bodies. It can also be profitably utilized as a primary geophysical exploration tool in areas of deep mineralization below the depth limit of conventional airborne and ground geophysical systems. The probed area of a diamond drill hole in these cases is increased from a 1- inch drill core to a zone extending hundreds of feet from the hole."

Jan 1, 1980

By Chuanhui Cao, Shimei Liu, Xiaojing Li, Yueyuan Zhou

"Force analysis on weakly-magnetic particles and non-magnetic particles in magnetic field are presented, using a kind of permanent magnetic drum magnetic separator, which is designed with strong specific magnetic force and open magnetic system. Its surface peak intensity reaches to 1.0T, and the distribution density of capture line is 1.25×103/dm2. Qualitative analysis on the particles including its magnetic property, particle size, motion speed, magnetic field intensity, etc. is also presented to calculate the separating parameters for the drum separator. Experiment was conducted for the separation of fine weakly magnetic minerals for example ilmenite. The practicability to separate the minerals using separator designed with open magnetic system has been proved, providing an economic way for efficient separation of micro-fine weakly magnetic minerals and upgrading of non-metallic minerals. INTRODUCTIONMagnetic separation is a mineral processing method based on the differences of magnetic properties between minerals in inhomogeneous magnetic field (Sun, 2007). Currently for separation of micro-disseminated weakly magnetic iron ore, electromagnetic high intensity magnetic separators with closed structure of magnet system are often used. And for the separation of strongly magnetic minerals such as magnetite, low intensity drum magnetic separators with open magnet system are often used. In order to lower the operation costs and improve energy efficiency, it is important to develop efficient high intensity permanent magnetic separator with open magnet system, to some extent replacing high intensity electromagnetic separator.Oberteuffer (1974) discussed the magnetic force and competing forces in magnetic separators which compete with the magnetic forces and act on all of the particles which travel through the separator are those of gravity, hydrodynamic drag, fraction, and inertia in magnetic separation."

Jan 1, 2016

By Michel David

"The usual complaint of mines is that grade does not match exploration expectations. Quite often, more tons are mined than expected but at a lower grade. This can be seen as dilution. Geostatistics can help predict which dilution can be expected both in terms of grade and tonnage for different mining methods.The usual vocabulary of geostatistics speaks of block distribution; block variance, size effect, information effect, all terms which say very little to the practitioner. In f act, all this can be rephrased in terms of dilution .In this paper, the following is presented - an example which shows how reserves change with the size of selection units and number of samples taken, and tables which show the dilution that are bound to happen when dealing with the commonly encountered log-normal distribution. Finally, the paper shows how grade tonnage computations should be made in the case of an arbitrary distribution. IntroductionGeostatistics progresses more and more rapidly if one judge s by the number and quality of papers published in Mathematical Geology or at APCOM meetings. More and more case studies describing successful applications are published (David et al., 1986)(Kwa and Mousset-Jones, 1987). It is estimated that more than 270/0 of the gold mines around the world use geostatistics. There is still, however, a lot of resistance from the remaining 73%. Geostatistics has more formulae and equations than it needs to reach year 2000. We will be well into the third millenium before all the models available now are actually used. The progress may come in the form of finding better ways to present known statistical results and getting away from the jargon of geostatisticians. One example may be in trying to explain how we can answer the most common plea of the mining industry: production grade is not what was expected in the feasibility study."

Jan 1, 1988

By M. Scobie, T. Atkinson

"This paper reviews the development of new designs in extensible and high angle conveyor systems. These aim to overcome the limitations of prior alternative concepts in design. The application of such systems in strip, terrace, open pit and mountain mining is reviewed. IntroductionTruck haulage costs have tended to escalate in recent years. This has been primarily due to operations generally moving to greater depths with associated increases in haul distances . Periods of high inflation rates have also been experienced for diesel fuel oil, tires and other petroleum based products. Recent international political events have tended to regenerate concerns over future oil supply and price stability. For such reasons, conveyor based transport is becoming increasingly attractive. Truck haulage maintains an inherent flexibility and improvements continue to be made in performance and capacity. Doubts must exist, however, over the extent to which further economies of scale may be made. Conversely, belt conveyor systems do not suffer this constraint and have the following advantages:• Electrical power is used and the specific energy consumption is at least half that required for truck haulage.• Operating costs and skilled labour requirements are lower.• Equipment has superior longevity and is ""inflation proof"" .• Access roads can be steeper and narrower in most mine environments, reducing construction and maintenance costs.• They are less prone to breakdown and bad weather delays .• In long haul, high capacity operations conveyors can save substantially on capital cost.• Environmental impact is improved with reduced noise level, dust and atmospheric pollution. Although conveyor systems are less flexible in operation than truck haulage and although a breakdown in any part of the system can immobilize the total system, mechanical availabilities of + 80% are constantly reported by large operators. There would appear in the past to have been some prejudice against conveyor systems in hard rock mines due to lack of experience. Apparent reservations would apply equally 10 underground coal mines, yet practically all of these mines (and some underground hard rock mines) find conveyor systems more economical than other transport systems."

Jan 1, 1991

By J. Peck, M. J. Scobie, M. D. Pollitt

"IntroductionOne aspect of current research in the Canadian Centre for Automation and Robotics in Mining (CCARM) involves the automatic identification of different rock types based on particular drill performance parameter responses. In this paper, the four drill performance parameters of torque, pulldown pressure, rotary speed and penetration rate, were measured from an instrumented rotary blasthole drill during field investigations undertaken at the Fording River Mine, Elkford, British Columbia. The variations in these parameters were subsequently correlated with the corresponding rock types using the results from gamma, neutron and core logs in the same or adjacent boreholes. Work to date has sought to understand the relationships between drilling performance parameter variation and rock properties. Using the results of these studies, the present research is aimed at developing techniques whereby classical statistical pattern recognition methods are applied to drill data to permit the discrimination of different rock units. A monitoring system incorporating such a capability would greatly enhance the quality and amount of geological information on a per borehole basis while drilling. This data in tum could be used economically and directly towards explosive loading, geological exploration and reserve estimation. Background and PhilosophyThis work is an extension of equipment monitoring studies at the Fording River Mine. At this site over a two-year period, 5180 m of data was acquired on an instrumented Bucyrus-Erie 60R drill during routine production blasthole drilling. Throughout these studies, a 311mm diameter S8M Security tungsten-carbide tricone bit was used. The mine, located in southeast British Columbia, is a large-scale, open pit coal operation. The means of excavation revolves around a drill-blast-muck cycle and employs a standard shovel-truck system of transport. Four main rock types are present: sandstone, siltstone, mudstone and coal, with average compressive strengths ranging from 10 MPa to 150MPa respectively (peck 1989). However, based on the field studies, very few differences in terms of strength and compositional properties were seen between the sandstones and siltstones at the site. Therefore, they are referred to as sandstone/siltstone in all further discussions."

Jan 1, 1991

By Li. L.

Backfilling has become a popular solution in underground mines around the world. It reduces environmental impact of mining industry and improves ground stability. In most cases, backfill has a high water content so that it can be delivered by pipes from a backfill plant on ground surface to underground stopes. Upon deposition in the stope, the backfill tends to consolidate under its own weight, leading to a generation of excess pore-water pressure. To avoid excessive pressure and protect the backfill barricade installed at the base of the stope, the backfilling of the stopes is usually divided into two stages: plug pour and backfill body pour. The interruption of backfilling operation is undesirable as it slowdowns the mining productivity, and sometimes causes pipe clogging, leading to unexpected increase in manpower cost and further reduction in mining productivity. The backfilling interruption time may be reduced, even eliminated if the drainage of backfilled stopes is sufficiently improved. This paper presents an application of wick drains, a material commonly used in civil engineering, to mine backfilled stopes to help accelerating the drainage. A protocol is proposed for installing the wick drains in a mine stope to be backfilled. Numerical simulations were made, showing that the drainage of the backfill can significantly be improved by the introduction of wick drains. The application of wick drains in mine backfill can thus be considered as a promising technique and merits deeper and more detailed investigation.

Aug 1, 2013

By B. D. H. Knights, N. B. du Preez

The recovery of the economy of the Democratic Republic of Congo has allowed for the rapid increase in production of copper from this region, while the increased price of cobalt continues to support the recovery of that country’s economy. This has enabled the modernization of the process technology used, particularly the change from direct electrowinning of copper to solvent extraction-electrowinning. With this change has come a variety of technical challenges in optimizing the recovery of cobalt from these sources. In this paper, we discuss aspects of the flowsheets for the production of cobalt from the ores of the DRC and Zambia, highlighting the technological improvements that have been made. Following this description of the practice, we assess the challenges of further improving the recovery and purity of cobalt from these sources. INTRODUCTION The African Copperbelt (Figure 1) is by far the biggest producer and holds the greatest reserves of cobalt (Sheed, 2015). However, the ores of this great mining region are extracted primarily for their copper content, and cobalt is a by-product. The ratio of copper-to-cobalt is between 6 and 20 to 1, with the ores from the DRC richer in cobalt than those from Zambia. The overall supply of cobalt, shown in Figure 2, is increasing due to an increase in demand for its use as a battery material. Cobalt is used in superalloys, hard metals, pigments, catalysts magnets, tyre adhesives, lithium-ion rechargeable batteries, and wear-resistant coatings, amongst others. Although these generic categories persist, Figure 3 shows how the relative usage of cobalt is changing due to the uptake of electric vehicles in China and Europe. Cobalt is a key element in lithium-ion batteries, and because it is widely anticipated that electric vehicles will be legislatively encouraged, it is anticipated that the demand for cobalt will rise. This anticipated increase in demand resulted in an increase in the price for cobalt, to which suppliers responded over-eagerly, and the price has dropped dramatically in the first few months of 2019, as shown in Figure 4. However, there is a clear cycle of price peaks in cobalt’s history.

Jan 1, 2019

By K. Tsuchihashi, A. Kishimoto, T. Uda, Y. Kado, S. Maruyama

We recently proposed a continuous production process for titanium metal with some experimental results. In the process, titanium tetrachloride is reduced by Mg in the presences of Bi to form a Bi-Ti alloy at 900ºC. At this temperature, the obtained alloy is liquid and allows for the continuous removal of product and heat from the reaction vessel. The obtained Bi-Ti alloy was vacuum-distilled at 1000ºC for 24 hr, and 98 at % (92 wt %) titanium, which was easily crashed to powder, was obtained. Bi solvent was selected because of the highest titanium solubility at 900ºC and the moderate vapor pressure among the candidate metals (Bi, Sn, Pb, Zn, and Sb).

Jan 1, 2014

By A. Mcdonald

"An X-Met Analyzer was purchased from Outokumpu in late 1983for use in the Hudson Bay Mining and Smelting smelter. Its first use was in the fuming plant to give zinc assays of each charge of slag tapped from the fuming furnaces. This quickly told the operators exactly when each charge had reached its economic tap-out point, and gave supervision a fool-proof method of identifying good operation. These and other factors led to major improvements in coal utilization in the fumers and to major increases in zinc oxide production. A second unit was later purchased for the reverberatory furnace to give silica and iron assays of the slag, and these were used to make adjustments in the feed composition to maintain the desired SiO2:Fe ratio in the slag. Since purchasing the units for the furnace, the oil consumption and copper content of the slag have dropped significantly. IntroductionSmelters have lagged far behind concentrators in process control by mean s of rapid product analysis. The on-stream X-ray analyzer was developed about seventeen years ago, and soon concentrators around the world were getting assays of the incoming ore, .concentrates and tailings every fifteen minutes, and using these to control reagent additions and other process variables. Almost always, the concentrate grade and recovery improved.In smelters, product streams are solids or molten materials, not the more easily handled slurries, and until seven years ago no inexpensive equipment was available to provide rapid analysis of this type of material. In approximately 1980, several companies developed instruments based on irradiating solid samples with low-intensity gamma rays from radio-isotope sources, and measuring the secondary X-rays emitted from different elements in the sample to provide an analysis of the elements desired.The smelter staff had a close look at what was needed and listed the following points as being critical:1. ability to provide Zn assays of a sample of slag within 15 minutes of taking it, in order to achieve optimum fuming times (zinc fuming , being a batch process, had the greatest potential benefit from rapid slag analysis);2. ability to give Cu and Fe assays on the slag, and on other smelter products, such as matte and converter slag;3. ability to give Si02 assays since the SiO2 content of the slag has a strong effect on fuming rate; and4. ability to stand up to an industrial atmosphere such as exists in the fuming plant."

Jan 1, 1987