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By G. Bonin, A. Jamal, G. Preciado, S. Gillis

"Accurate, easy to obtain, and reliable methods of measurement are the cornerstone of shaft and tunnel developments - during their sinking, operation and maintenance, or in some cases, remediation. This paper presents a new methodology to capture existing shaft conditions in such a manner that they can be transferred from the field to a digital copy, where they can be stored and used for engineering design purposes in a space not directly affected by the costs associated with schedule and equipment performance. The methodology utilizes basic principles of excavation alignment (plumb lines and survey instruments) while adding modern LiDAR, geolocation and survey control tools that can more completely capture the surrounding environment. The complete cycle of collection, processing, and delivery of pertinent information underground can take under an hour. During sinking, capturing data as a live stream measurement and being able to assess the alignment of the shaft liner can be critical to meeting rigid design tolerances. As sinking progresses, small changes in alignment or liner deviations can be captured and immediately corrected. Likewise, post-construction as-built conditions can be recorded and digitized, which will allow the mine personnel to compare the proper working condition to the actual condition years later. Observed changes can be identified and planned as future shaft repair works. This methodology has been developed and successfully deployed during the on-going sinking works of the two shafts at the Jansen Potash Project in south-central Saskatchewan and is described in greater detail in this paper.INTRODUCTION Light Detection and Ranging (or LiDAR) scans of the BHP Jansen Production and Service shafts during construction identified sections of both shafts where the internal radius of the temporary primary liner was insufficient to accommodate the tolerances of the permanent liner that was to be installed inside the temporary liner. These locations are referred to as “tights”. The “Tights Removal Program” was designed to collect high resolution point clouds of the shaft, using stringent survey control, that could be compared to the design profile to generate a heat map of locations for removal of up to 75 mm of steel-fiber-reinforced, 70 MPa concrete liner. This work was all on critical path, which made it valuable to save time on the schedule. Because concrete removal was a time-intensive task, it was essential to locate and remove only the concrete that would encroach on the planned permanent liner, while attempting to maximize the amount of cutting time. Removal was carried by a road header attached to a Brokk(R) 160, a small multi-attachment demolition machine."

Jan 1, 2019

By A. I. Collins, D. Danninger

Newmont has installed advanced control and online optimization on the dry grinding circuit and both roasters on its Carlin Trend refractory ore treatment plant. Subsequently, Newmont has developed a master plan for institutionalizing advanced control and optimization on all its processing units. Newmont is committed to a program of applying advanced control and optimization from crushing of ore to pouring of gold. This paper describes Newmont's experience with implementing advanced control and optimization and the benefits received. In addition, identification of advanced control and optimization opportunities and their economic justification is discussed.

Jan 1, 2005

By Filip Rochette, Yvan De Busscher

Extraction of minerals can be achieved by a variety of technologies; one of them is ion exchange. There are several ion exchange configurations and mechanical set-ups available, but only one technology will provide more process performance and flexibility compared to the other. The multiple column Continuous Countercurrent Ion Exchange (CCIX) technology provides the highest form of process flexibility with also the highest mineral recovery feasible through ion exchange. In comparison with a fixed bed system, the PuriTech CCIX system offers the benefits of continuous counter-current contact mode. This way the resin capacity is fully exploited leading to reduction in resin inventory and, at the same time, in chemicals and water consumption, and product dilution. For any set of operating conditions the mass transfer zone has a characteristic length (MTZL). The MTZL can be expressed in duration, column length, or volume, but is the measure of the quantity of resin in the system that is doing "work" at any given moment in the process. The objective of continuous ion exchange processing is to eliminate all resin volume from the process equipment that is not within a mass transfer zone. In most commercial ion exchange processes for the recovery of metals, CCIX engineering can eliminate as much as 20 - 80 % of the ion exchange resin inventory. Consumptions of water and chemicals are typically brought down around 40% or more. For each type of resin the selectivity/affinity towards a particular metal depends on the basic process conditions such as pH, concentrations of other competing metals in solution. By changing the pH in the ion exchange process phase, the selectivity of the resin can be changed. By doing this, a split elution, or extraction of metals separately can be achieved and the effect of other competing metals (cross-contamination) can be reduced. For example the DOW resin XUS43578 is commonly used for the recovery of copper or nickel/cobalt separation.

Jan 1, 2016

By J. J. Laffin

In the pursuit of comfort and safety, the wonders of science have given us controlled heating and cooling, thus enabling us to enjoy all the aspects of present-day living to an extreme never previously •envisaged. Man's attempt to conquer the elements largely involves con-trolling the temperature around him. Without having conquered this aspect, his body energy would be consumed in trying to maintain physical comfort, rather than being invested in the explorations which have resulted in man's control over the forces of nature. The indirect methods used to obtain the most agreeable temperature environment were developed because of the natural tendency to strive for increased safety, convenience and comfort. Until the twentieth century, when heat generated by atomic fission became a reality, man's only source of heat, except for that of the sun, came from his discovery of fire.

Jan 1, 1962

By G. Deschênes

The Eleonore property (James Bay district of Northern Québec), owned by Goldcorp, hosts gold within stockworks of quartz-tourmaline-arsenopyrite veins and veinlets contained within microcline (potassic alteration) and brown tourmaline replacement zones. The preliminary investigation to recover gold from drill core samples showed that flotation followed ultrafine grinding and cyanidation is the preferred option. Ultrafine grinding is used to liberate gold finely disseminated in sulphides. The flotation concentrate used in the investigation had a P80 of 11 microns and contained 75.5 g/t Au, 5.0 g/t Ag, 10.3% S, 0.07% Cu and traces of antimony (0.03%). The mineralogical characterization showed the presence of 65% gangue minerals, 23% pyrrhotite (hexagonal), 9.6% arsenopyrite, 2.2% pyrite and 0.08% chalcopyrite with trace amounts of galena (0.05%) and sphalerite (0.03%). Gold was in the form of native gold and electrum. A straight cyanidation conducted at pH 11.0, DO of 3-5 ppm, 2000 ppm NaCN, 20 C 72 hours extracted 97.0% Au and consumed 31.5 kg/t NaCN. The equilibrium was reached within 24 hours. Increasing the dissolved oxygen to 16 ppm reduced the consumption of cyanide to 22.0 kg/t with 96.7% Au extraction. A 16-h pretreatment with 2.0 kg/t lead nitrate, followed by a 24-h cyanidation reduced the cyanide consumption to 6.0 kg/t with a gold extraction of 97.5%. Increasing the lead nitrate addition to 6.0 kg/t reduced the cyanide consumption to 1.2 kg/t by passivating the surface of pyrrhotite. The gold extraction remained at 97.0%. It was possible to decrease the concentration of cyanide to 800 ppm NaCN without compromising gold extraction. The associated cyanide consumption was 1.2 kg/t NaCN. The passivation of gold grains was an issue when the cyanide concentration was decreased to 550 ppm NaCN. The gold extraction decreased to 92.2%. The average lime addition for all the tests was 7.4 kg/t and the average silver extraction was 80%. Efficient cyanidation of an ultrafine sulphide concentrate with only 800 ppm NaCN represents an advance in leaching of ultrafine sulphide concentrates.

Jan 1, 2013

By Roussos Dimitrakopoulos

Conventional approaches to estimating reserves and optimizing mine planning and production forecasting result in single, often biased forecasts. This is largely due to the non-linear propagation of errors in understanding orebody attributes from a limited finite number of drilling data, throughout the chain of mine planning and mining. A new mine planning paradign is considered herein to include two interacting and potentially fusing elements: stochastic simulation and stochastic optimization. These two elements provide an expanded mathematical framework that allows the modelling of orebody uncertainty and its direct integration to mine design, production planning and valuation of mining projects and operations. This stochastic framework has shown to increase the value of production schedules in the order of 25%. In addition, case studies show that stochastic optimal pit limits are about 15% larger in terms of total tonnage, compared to the conventional (deterministic) optimal pit limits. This difference extends life of mine and adds approximately 10% of net present value (NPV) to the NPV reported above from stochastic production scheduling within the conventionally optimal pit limits. Furthermore, results suggest a potential new contribution to the sustainable utilization of natural resources.

Oct 1, 2009

By G. B. Harris, C. W. White

A study to investigate the recovery of base metals, notably copper, nickel, cobalt, zinc and manganese from iron-free concentrated chloride solutions using ion exchange was undertaken. In such solutions, apart from nickel and, to a lesser extent manganese, these metals are present predominantly as complex anions, and therefore conventional separation techniques based on cationic resins are not applicable. The results demonstrated that zinc, copper and cobalt can all be separately recovered leaving nickel and manganese behind. Specifically, zinc is a major nuisance element in nickel and cobalt processing, and the testwork showed that it can be preferentially removed prior to copper and cobalt. Selective resins for both copper and cobalt were identified, and it was demonstrated that the strength of the chloride background matrix has a significant effect on the efficiency of separation. An additional major advantage in such systems is that stripping can mostly be effected with water. Finally, some observations are made on the hurdles that must be overcome when attempting to introduce and commercialise new technologies.

Jan 1, 2015

By Eugene Nel, Johan Theron, Chris Martin, Hans Raabe

"Impala Platinum Limited is the world’s second largest platinum producer, producing more than 1.7 million ounces of the precious metal last year, much of this from the UG-2 reef located in the Bushveld Complex, South Africa. As part of Impala’s ongoing expansion programme, tonnage through their principal UG-2 processing facility, near Rustenburg, was increased 40% in 2001.To accommodate the increased throughput, the role of the existing primary mills was converted from conventional semi-autogenous grinding units, to attrition and selective grinding units, operating in fully autogenous mode. The finer chromite and coarser silicate components in the mill discharge are then separated by screening and processed in dedicated circuits downstream. This way, the need to spend considerable capital to increase primary grinding capacity was averted.In the last year, considerable work has been conducted to evaluate and optimise the two downstream circuits. This has involved an optimisation programme of sampling and diagnostic flotation testing, supported with QemSCAN analysis. This paper will describe the operation of the new circuit. It will also describe some of the more novel aspects and interesting findings from the optimisation programme.INTRODUCTIONThe South African platinum industry is the world’s largest producer of platinum and the world’s second largest producer of palladium. Located in a wide area north of Johannesburg, the industry mines ores from the Bushveld Complex, one of the world’s great mineral treasure chests, containing over 70 percent of the world’s platinum, as well as extensive reserves of the other PGE (platinum group elements), chrome, manganese and vanadium. The industry employs about 180,000 people in, predominantly, underground mines, which together form an almost unbroken circle of mining operations 200 km in diameter."

Jan 1, 2004

By Robert Martin

New Millennium ?a new project for an experienced mine building team ?Owns 100% of KeMag(Harris Lake) property ?Owns 80% of LabMag(Howells River) property -20% owned by Naskapi Nations of Kawawachikamah ?All founding directors are mining professionals : Geologists or Mining Engineers ?All have extensive experience in the iron ore industry ?The Project Office is located in Montreal, lead by a team of experienced iron-ore professionals Project Overview Geology & Resources Market Prospects Process & Product Development Development Plan Questions

May 1, 2007

By Gavin C. Dirom

? The Mining Association of British Columbia (MABC) was established through an Act of Parliament in 1901 ? The MABC represents the interests of B.C.?s ? Coal and mineral mining companies ? Smelting companies ? Advanced stage development projects ? Key areas of work: ? Environment, Health and Safety ? Policy & Government Relations ? Knowledge and Information Services

May 1, 2008

By Glenn Kosick, John Starkey, Glenn Dobby

"A practical new test has been developed for SAG hardness determination. Using two kilogram samples of minus one inch diamond drill core or crushed muck samples, the Starkey SAG Test has been shown to give accurate predictive information which directly relates to on-stream SAG mill performance. Typical results and test criteria are discussed in the paperAchievements to date include:• Identification of hardness profiles and the location of hard and soft zones in a large ore body.• Accurate prediction of the hardness of a bulk sample by using an adjacent diamond drill hole.• Derivation of a plotted curve relating pilot plant power to laboratory relative hardness.• Demonstration that for every test done to date, the Starkey SAG Test produced a product size distribution identical to that produced in a pilot plant or full scale plant SAG operation.This test can now be used for blast hardness monitoring and short term control of mine production in existing plants and for identifying the proper locations for bulk samples in new projects. In addition, new SAG mill design can now be rationalized in a low cost way to eliminate unforeseen production shortfalls.IntroductionThis paper is presented to introduce the Starkey SAG Test, a practical new laboratory tool for measuring the relative hardness of small ore samples in a semi-autogenous grinding (SAG) environment. The test was first designed for use on diamond drill core samples during the prefeasibility stage of new mining projects, to provide new information about the ore body at reasonable cost. It is a new tool and does not replace existing pilot plant test requirements.The test will also be useful for throughput prediction in existing SAG plants by assisting in short and long term mine planning, where forecasting of metal grades and milled tonnage is used to control mine profitability. Because in-plant hardness testing has previously been unavailable on small samples, this test offers exciting possibilities for SAG mill operations where hardness variation is or could be a problem.The Starkey SAG Test provides the following benefits to the mining industry"

Jan 1, 1994

By Tapio Leskinen

"l. IntroductionA reliable sampling system is the basis for an on-stream analyzer. This was realized in Outokumpu company when the development work of the Courier 300 On-Stream X-ray analysis system was started. Because Outokumpu Oy is a mining and mineral processing company, its engineers have been able to thoroughly test sampler prototypes in actual operating situations. The sampler development has been going for several years in close co-operation between company's concentrators, the Institute of Physics and the Instrument Division of Outokumpu Oy. The most active part of the work was done between 1969- 1972. Besides the reliable operation of a sampler special attention was paid to the representatively of the samples taken by the samplers. 2. The Courier 300 Sampling SystemThe sampling system comprises up to fourteen sampling circuits in one Courier analysis system. Each circuit consists of the following components:1. Primary sampler 2. Secondary sampler 3. Cleaner screen 4. Feeding tank5. Sample cell6. Timer-controlled sampler7. Pumps, sumps and pipesSecondary samplers, cleaner screen and feeding tanks are included in the secondary sct1npling system. The sample cells are located in the spectrometer cabinet of the analyzer."

Jan 1, 1976

By J. Kazakoff

"The success of gold recovery at the Jolu gold mill depends on many variables. The most important ones are the people, the ore body, plant design parameters, equipment selection and cost control. This paper will briefly hiqhlight the above, the main focus, however will be on the gravity gold circuit.The gravity circuit requires judicious operator attention in order to operate properly. In return the circuit gives immediate visual results for mill peopleIntroductionThe development of the Jolu property to the production stage was carried out quickly, efficiently and economically. The property became a gold producer ahead of schedule and under budget.The Jolu property is a joint venture between International Mahogany Corp., a 70% partner, and Corona Corporation, a 30% partner. Corona Corporation operates the Jolu Gold Mine, located 140 kilometers north of LaRonge and 520 kilometers north of Saskatoon."

Jan 1, 1990

By A. F. Banks

"The last time I spoke to you the potash industry was at a low point. Markets were bad and the industry depressed. Many people had left and there was very little being done in terms of development. The current situation is very much changed. The oversupply conditions have given way to a very tight supply capability. All of the firms in the business are expanding in one way or another. These expansions will run from simple debottlenecking through to complete new projects.In New Brunswick, the Potash Corporation of America is proceeding with a new project and the Dennison - Potacan Project is in progress. In Saskatchewan, the Potash Corporation of Saskatchewan has an ambitious 2.5 billion dollar expansion program underway while those in the private sector are taking a somewhat less ambitious but equally significant approach to obtain further tonnage out of existing facilities.The significance of these expansions to mineral processors is that we can expect to see expanded employment opportunities and through necessity a surge in innovation and development in an industry that has been traditionally very conservative. This presentation will review potash processing with a view towards highlighting some of the more recent developments."

Jan 1, 1982

By J. Nesset, F. Rosenblum, P. Spira

"Sulphide concentrates may exhibit self-heating to various degrees during storage or shipping, the worst cases presenting a serious hazard from fire and SO2 emission. Based on measurements of heating rates on a wide variety of concentrate samples in a special apparatus, combined with field experience, a methodology has been developed which allows concentrates to be rated for their heating potential. This has proven to be very useful in practice, for example, in deciding on the need to take preventive measures. Oxidation under ambient conditions in the presence of moisture initiates heating locally within a stockpile. In the case of highly active materials, such as those that contain abundant pyrrhotite, heating may progress through three stages to temperatures well above 5000C. However, most concentrates show little or no propensity to selfheat. Heating rates were used to estimate values of the heat output, or self-heating capacity (in joules per gram), which sustains the process at each stage. Thermal data from differential scanning calorimetry are also reported. Variables which affect self-heating are discussed and an actual case of heating control on a stockpile by covering is described. A simple apparatus which can be used to simulate stockpiling conditions has been tested successfully and is proposed as a convenient test system.INTRODUCTIONPrevious publications from this laboratory on the evaluation of self-heating in sulphides dealt with tailings backfill (Rosenblum et al. 1982) and waste rock (Rosenblum and Spira 1995). Sulphide concentrates may likewise exhibit self-heating in storage or during shipping. In a comprehensive but dated review, Kirshenbaum (1 968) pointed out the conflicting nature of information on means of controlling the problem, particularly with regard to the application of water and ventilation. Modelling by Simpson (1 97 1) of autogenous heating in stockpiled zinclead concentrate and associated field measurements by Wright et al. (1972) showed that the supply of oxygen by wind and the shape of the piles were the major factors in the development of hot spots. Simpson did not attempt to explain the complex mechanism of self-heating, simply ascribing its onset to oxidation. Pearse (1 980) investigated a potential method of testing for selfheating which consisted of (i) reaction with hydrogen peroxide and (ii) differential thermal anal sis, to characterize the response of concentrates at both ambient and temperatures above 100 C. He found the method sensitive enough to identify the need for careful handling but not to predict ignition. He recommended compacting concentrates and covering stockpiles with plastic sheeting to prevent ingress of air. All these workers recognized the key role played by oxygen and moisture in triggering self-heating."

Jan 1, 2001

By R. K. Jonas

"Pressure leaching and pressure oxidation in autoclaves are important alternatives in the extractive processing of gold, copper and nickel ores. The application of advanced control to pressure leach and pressure oxidation autoclaves could achieve significant benefits as has been shown in alumina pressure leaching. This paper compares and contrasts alumina digestion autoclaves to other mining autoclaves with respect to advanced controls. The application of advanced control in alumina with over 30 units controlled worldwide, and its benefits will be reviewed. The design and potential benefits from advanced control for pressure oxidation and leaching will be presented.INTRODUCTIONIt is this author's position and the purpose of this paper to propose that advanced control could be effectively applied to autoclaves in the nickel, gold, and copper mining processes. This is based on the proven effectiveness of advanced control on autoclaves used in the alumina industry for pressure leaching of bauxite ores. Incremental, but significant increases in production could be realized by applying advanced control to autoclaves, as evidenced by the alumina industry, and this not being implemented in other autoclaves in the mining industry.In addition, today the mining industry is being challenged to improve their production methods. In some markets like nickel, there is pressure to improve productivity and reduce the cash cost per ton. While in other markets like copper and gold, demand is vigorous with favourable pricing, and there are advantages to increase production and productivity given limited plant capacity. Advanced control has proven its capability to improve mineral processing operations through increases in throughput, recovery, as well as reducing variability. In today's mines, autoclaves are being used to a much larger scale and with much larger importance, thus it would be beneficial to improve operational performance through the use of advanced control.Accordingly, it is the author supposition that an opportunity exists in the mining industry to use a proven advanced control technology to improve the operations and financial performance of mines using autoclaves."

Jan 1, 2012

By Shichang Liu, Hongli Jia, Zhaolian Wang, Maotang Liu, Ltd. Shandong Huate Magnet Technology Co., Fengliang Liu

"Introduce and promote a latest technology and equipment for magnetite. It’s featured of purifying concentrate, lowering tailing grade, high concentrate recovery rate and stable operation. HUATE® New Style Elutriation Electromagnetic Separator is an equipment to obviously upgrade magnetite. The slurry is fed into separation area through feeder. Generated by excitation coil, the working magnetic field distributes specially in separation area. Under the combined effect of the background field, excitation and demagnetic field and gravity, the mineral particles float downwards in the form of magnetic chains, and interact with the rising water. The gangue, non-magnetic particles, lean intergrowth,etc will be discarded as tailing via overflow tank and pipe. While the magnetic will be discharged from concentrate pipe. Its grade is 2%-10% higher than that of traditional magnetic separation equipment. It adopts the technologies of transformer oil cooling, alternative and uniform pulsation magnetic field controlling the tailing grade, larger drum feed-in device, more uniform umbrella scattering discharge and stabler output current, and realizes lower coil temperature raise, stabler magnetic field, more uniform discharge, effective isolation of weak-magnetic area from non-magnetic area, more obvious upgradation and recovery rate and lowering tailing mFe%. It’s more suitable to purify and thicken the high grade and ultrafine iron powder. Compared with traditional elutriation equipment, it adopts new technologies in removing impurities, operation, large-scale, process simplification, water-saving, remote control, etc. It optimizes the comprehensive beneficiation index, expands its application scope, reduces resource wastes and increases economic benefits.INTRODUCTIONMagnetite accounts for a comparatively great proportion in various iron resources. As it’s a kind of strong magnetic mineral, we must adopt the weak magnetic separation equipment in magnetic separation process to realize removing Si and lowering impurities. While it cannot do very well to use the common weak magnetic separation equipment in the final cleaning to remove Si and lower impurities. At present, the plants, adopting single magnetic separation process to realize cleaning and removing Si and lowering impurities, are in the minority. Most magnetite plants adopt the flotation separation process to remove Si, lower impurities and purify the concentrate. Though with stable indexes and high Fe recovery rate, the flotation process is very complicated, high-cost and with lots of environmental pollution. If adopting the weak magnetic separation equipment can realize removing Si, lowering impurities and the final cleaning, the magnetic separation process should be the primary choice."

Jan 1, 2016

By M. Massinaei, M. R. Yarahmadi, S. Zeidabadi, M. Oliazadeh

"Although the majority of new flotation column installations continue to be for cleaning or recleaning, an increasing number of flotation projects are specifying columns for roughing or scavenging duties. NICICO has recently installed flotation columns operating in rougher, cleaner and re-cleaner circuits at three new copper concentrators; Miduk, Sungun and Sarcheshmeh. Miduk is probably one of the unique operations that use flotation columns in a rougher circuit. The Miduk rougher circuit comprises five CISA parallel columns. The rougher concentrate constitutes 88% of final concentrate and reports to concentrate thickener. The rougher tailings are scavenged with ten 50 m3 mechanical cells. The scavenger concentrate is then reground and cleaned in three 3.2 m columns in parallel. The cleaner tailings are scavenged in six 50 m37mechanical cells. The cleaner tailings along with the rougher scavenger constitute final tailings.In Sarcheshmeh, the cleaner concentrate is re-cleaned in a column. The column tailings are sent back to the cleaning circuit and the concentrate is reported to the concentrate thickener.This paper reviews performance details of the flotation columns utilized in rougher circuits at Miduk and compares their metallurgical performances in an industrial scale with columns at cleaning circuits for copper flotation. Practical limitations for applying the flotation columns in rougher circuits will be discussed in details.INTRODUCTIONThe use of flotation columns has grown rapidly since the first successful commercial application at Mines Gaspe, where columns were used in a cleaning circuit to float molybdenite. Early applications of columns were restricted to replacing or adding final cleaning stages in existing circuits. Columns can achieve superior cleaning as compared to conventional cells due to their ability to support a large froth depth and the use of water for washing froth. Wash water travels down through the froth and crosses the pulp/froth interface, replaces the entrained particles reporting to the froth from pulp and improve the concentrate grade."

Jan 1, 2011

By G. S. Hume

Introduction Core drilling of the bituminous sands of northern Alberta has been carried on by the Mines and Geology Branch, Department of Mines and Resources, under the supervision of the Director, W. B. Timm. This was part of the Dominion Government's wartime investigations, which included an agreement with Abasand Oils, Limited, for the study of commercial possibilities of obtaining oil from the bituminous sands. The drilling programme, commenced in 1942 by the Consolidated Mining and Smelting Company of Canada, was continued in 1943 and subsequently by Boyles Bros. under contract with the Mines and Geology Branch. Several areas have been investigated and one of these, the Mildred-Ruth Lakes area, ' herein described, is of special importance in that it contains a sufficiently rich and large deposit of bituminous sands and bitumen beds to warrant consideration of commercial developments for the production of oil. The Steepbank Area, East Side of Athabaska River The Steepbank area, on the east side of Athabaska river in township 92, about twenty-two miles north of Fort McMurray, was selected for drilling in 1942 because previous investigations by Ells indicated it was one of considerable promise both from the standpoint of having reasonably rich bituminous sands under relatively light overburden and also having an excellent tailing disposal and plant site for large-scale operations in proximity to Athabaska river. The drilling done in 1942 and 1943 was largely exploratory, and, when it was found that the southerly part of township 92 had only low-grade material, closer drilling was done in 1944-45 in the richer, more northerly part.

Jan 1, 1947

By Peter Fullagar, Adel Vatandoost, Steve Walters, Toni Kojovic

"Traditional comminution tests are a vital component in every mine plant design. Comminution behavior governs both the cost of equipment and its operating efficiency. Most comminution tests are conducted off site on a limited number of samples, owing to the high costs and long lead times involved. Therefore a strong incentive exists to find alternative means for efficiently characterizing comminution behavior for a truly representative suite of samples. The potential for inferring comminution behavior from drill core is investigated in this paper. Our approach involves development of small scale comminution tests on the one hand, and measurement of a wide range of core attributes on the other. Our focus is the relationship between petrophysical properties and comminution behavior.Petrophysical properties of archival diamond drill core from the Ernest Henry Mine (Queensland, Australia) have been measured using a Geotek multi-sensor petrophysical core logger. We have investigated the relationship between the petrophysical properties and the corresponding small scale A*b and estimated Bond mill work index test results for 2m composites of the core. Core samples were petrophysically classified by means of cluster analysis. Comminution behaviour was then modeled for each cluster via multiple regression. The results suggest that prediction of the comminution behavior on the basis of petrophysics is viable at Ernest Henry.INTRODUCTIONMineral processing is the most important downstream operation for mining engineers and metallurgists since most mined materials are subjected to some type of comminution or beneficiation operation (SME, 1992). Comminution or size reduction is typically the first stage of processing. Size reduction steps (crushing and grinding) in any plant consume large amounts of energy, normally more than 50% of total energy (Weiss, 1985). Therefore, it is desirable to obtain laboratory results to design the size reduction equipment appropriately. One of the main factors that control the selection of hard-rock crushing equipment and the design of a crushing circuit is the mechanical character of the ore(s). Work index, density, abrasivity, compressive strength and clay content are essential parameters for ore characterisation (SME, 1992)."

Jan 1, 2009