Search Documents

By G. E. Agar, R. Stratton-Crawley

"The applicability of a hydrocyclone model to simulation of the cyclone banks in a multi-stage sandplant circuit producing mine back fill has been demonstrated. The model ha~; been used in conjunction with a modular computer program for circuit simulation in order to study the effect of changes in the operating conditions. It has been shown that weight recovery to sand fill increases as feed percent solids decreases, and, to a lesser extent as pressure drop across the banks increases. An increase in apex diameter also causes an increase in weight recovery. Increased weight recovery must, however, be balanced against sump an1l cyclone capacity and dilution of sand fill by fines. The predicted results from circuit simulation were in good agreement with plant data.The model has been found to be applicable to widely different ores."

Jan 1, 1979

By D. W. Morgan, K. W. Downes

"OVER half a million tons of chromite ore is used annually on the North American continent, all of which is imported from overseas. Chromite is essential in the manufacture of stainless steel, armour plate, and tool steel, to mention only three important uses. It is, therefore, a strategic mineral, and every effort should be made to discover a means of utilizing our domestic supplies.Both Canada and the United States possess deposits of chromite, but they are low grade with respect both to their chromium content and to the ratio of chromium to iron. Mechanical concentration can improve the chromium content •by rejecting gangue, but chromium concentrate produced is still lower in chromium than imported chromite and, more important, the ratio of chromium to iron is only about half that in the imported material. At present, a chromium to iron ratio •of 3:1 is desired by industry. To obtain this .ratio in the case of domestic ores, a chemical attack on the chromi'e is necessary."

Jan 1, 1952

By Stephen Williams

This paper examines manning best practice in the Australian mining industry. In particular, the paper considers a range of mining operations and their manning levels as measured by operational benchmarking. The benchmarking results presented cover 15 open pit and 37 underground studies in Australia. The data was collected as part of AMC?s benchmarking and operational improvement studies conducted between 1999 and 2008. The results examine overall manning levels in mining, processing and administration functions. Manning levels for a range of mining methods, including open pit and underground methods, are segmented. Productivity measures such as ore tonnes per man day and metres developed per man day are presented and where direct relationships can be established, the relationships are described. Finally, the paper considers perspectives on best practice with regard to manning in the Australian mining industry and the limitations in application of this type of analysis in a global context.

May 1, 2009

By K-A. Adamson

If fuel cells and hydrogen are to become a mass market reality a substantial amount of further research and development needs to be undertaken. Work in hydrogen storage, production, the economics of all aspects of fuel cells and hydrogen, materials balances, and product integration are just a few of the areas that are under focus. Setting R&D targets, and providing R&D funding are therefore areas that are central to the long term development of the market, and areas in which a number of governments worldwide are highly active. Some governments, such as Japan and Korea, have set a number of very ambitious, highly focused, long term targets and are backing this up with substantial funding, others such as the EU are working on a more integrated approach, wrapping some fairly fundamental R&D into large integrated projects which run in combination with a number of other market aspects, such as public acceptance and roadmapping. The US is slightly different, in that although is has a number of long term programmes and targets, FreedomCar and SuperGen being just two, the levels of funding are set annually with the passing of each years Fiscal Budget. This paper takes three high profile regions and analyses the R&D targets and funding levels for fuel cells and hydrogen. Criteria that will be looked at include: Time frame of target(s), level of ambition, funding issues, including: Funding windows, levels available, funding barriers, overall programme goals. The added value to this paper is that it will provide a clearer picture of where each region is heading, what are its strengths and weaknesses, in terms of R&D and where there may be areas for potential international collaboration.

Jan 1, 2005

By Brian Putland, Fred Kock, Leigh Siddall

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012

By J. W. Matousek

"Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2>one atmosphere pressure) is given by the following:%[Fe] = 62.0 – 0.775%[Cu]%[S] = 28.0 – 0.00125%[Cu]2%[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu]2Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulphur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition."

Jan 1, 1996

By Pavel Vasak

Microseismic monitoring is becoming standard practice in the Canadian mining industry, particularly as mines get deeper. Full-waveform microseismic systems allow the operator to distinguish the event source mechanism, e.g., blast, shear slip or stress-induced fracture. At mine sites that heave a microseismic system operator blasts are manually identified by comparing the event waveform traces to the morning blast logs. However, this procedure is not routinely done at sites where a system operator is not present and this can lead to misinterpretation of the data at a later stage, particularly where the interpretation is outsourced, often many years later. It is critical to improve the microseismic data quality and consistency for processing and interpretation with a reliable technique to filter out blasts and blast related seismicity. This paper presents the development and implementation of a simple blast identification and filtering routine. The routine was developed specifically for Vale?s Creighton Mine about a decade ago, but is made sufficiently general so that it can be used at any mine site with an ESG (Engineering Seismology Group Canada) based full-waveform microseismic systems. The routine is strictly a post-processing procedure developed for use with the Access database data structure used by ESG. The algorithm was tested at Creighton Mine and a success rate of 80 to 90% was achieved, when compared to manual blast picks.

Oct 1, 2010

By J. Gillies

"Extraction of Gold in Ketone from a suitably prepared sample of sulphide or siliceous ore or concentrate permits a rapid and accurate determination by Atomic Absorption. Mill test products and exploration development samples are acid-treated to effect complete dissolution of silver, copper, zinc, lead, molybdenum and iron present. Interferences in the determination of molybdenum are described. Results by Atomic Absorption are comparable to those afforded by other acceptable methods.INTRODUCTIONDuring recent years much has been written and discussed concerning Atomic Absorption Spectrometry as a technique for determining the concentration of metallic elements. We would, however, recommend a perusal of the paper presented by J. C. Ingles at the annual meeting of Canadian Gold Metallurgists held in Ottawa, January, 1966. The paper was published in the August, 1966, issue of the Canadian Mining Journal, and contains general information on Atomic Absorption.The purpose of our paper is to present certain specific method procedures for the determination of several precious and base metals normally present in Mine, Mill and Smelter products. Of necessity, analytical results should be as accurate as the most suitable available method permits, whether for metallurgical balance, settlement purpose, ore beneficiation programs, or exploration property development. The success of such programs is relative to the accuracy, speed and economics of the analysis. It is obvious, therefore, that in presenting our paper we consider the technique has achieved the desired evaluation."

Jan 1, 1968

By J. K. Van Beek

The Deep Underground Science and Engineering Laboratory (DUSEL) is a scientific facility that will be placed in the deeper reaches of the Homestake mine, Lead, SD. Our team of geologists and engineers is carrying out the first scientific project awarded to the site ? Towards a Transparent Earth. Taking advantage of the thousands of open exploratory and sand-line holes, we are installing the beginnings of a seismic observatory. Each installed station consists of a 3-D accelerometer package and a 1 nanoradian 2-D tilt meter. In order to allow for a variety of monitoring and characterization studies, the array instruments are sensitive over the frequency bandwidth of 0.2 - 1 KHz. Three, three component accelerometer stations are currently installed ? in a 140 m deep bore beneath the slurry pump house, and in 12 m deep bores on the 2000-foot level, 800 and 400 m from the Ross shaft. There is a tilt-meter installed at each 2000 level station. These installations are in 150 mm diameter sand-holes. From the currently installed tilt sensors we are investigating solid earth deformation as a response to tidal potential. The accelerometers are being used to locate and characterize events associated with mine dewatering and rehabilitation.

May 1, 2009

By A. Putz, F. Vincent, A. R. Laplante

"This paper briefly reviews some of the gravity research done at McGill University and current Canadian operating practices, with emphasis on results of interest for operators. The following topics are addressed: security, economics, predicting recovery, circuit optimization, unit selection and final upgrading. Emphasis is placed on the Knelson Concentrator.The topic of security and economics are addressed jointly, in terms of the place of the gravity circuit in the mill flowsheet. Actual plant experience is drawn upon to identify potential problems and actual solutions.Predicting primary recovery is linked with a characterization of the ore, the choice of a circuit, and the fraction of the bleed used. Factors such as feed preparation, preliminary upgrading, fraction of recycle treated, ability to recover fines and location of the bleed are discussed.Final upgrading is achieved almost only by tabling and smelting. This can lead to fine gold recovery problems when more effective units are used upstream. Alternatives are discussed.IntroductionResearch on gold recovery by gravity over the past eight years has associated McGill University with a number of gold producers. This paper attempts to review the information gathered from a practical perspective. Some of the information was generated in McGill University's labs, some gathered at plant site, and some was shared by operators."

Jan 1, 1994

By O. Guyot, A. Broussaud, M. Revalor, G. Legrand, D. Kok, E. Roux

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

Jan 1, 2012

By Caitlyn J. McKinley, Ahmad Ghahreman, Maziar E. Sauber

Ever-growing global needs for critical metals, such as rare earth elements (REE), and base metals, such as copper and nickel, and their environmental impact motivated the pursuit of sustainable flowsheets. Regeneration of hydrochloric acid in chloride-based leaching flowsheets as a critical unit operation is an example of such endeavours. This study presents an efficient hydrochloric acid regeneration method from a magnesium chloride solution waste by addition of sulphuric acid in relatively low temperatures. The effects of temperature, initial magnesium chloride concentration, amount of sulphuric acid added, and airflow are examined. Experimental work are focused on temperatures between 80 and 95°C, initial magnesium chloride concentrations of 2 to 5 M, 100% to 220% stoichiometric sulphuric acid additions, and airflows between 200 to 600 mL/min. The developed technology recovers hydrochloric acid at a high rate and concentration with a relatively small environmental footprint. INTRODUCTION The mining and metals sector is under increasing environmental and economic pressure to make more efficient use of chemical reagents and energy in the production process. This affects several areas of process and flowsheet design such as the selection of the most appropriate unit operations and the overall design of the process steps paying heed to sustainability. Owing to the inherent inefficiencies of physical and chemical processes used in the mining industry, there will be materials and streams generated that are not a desirable part of the envisaged flowsheet. Thus, methods are implemented to recover and recycle such effluents. If the recovery and recycling are not economical, then procedures are followed to neutralize and dispose these effluents. In many cases, these effluents are potential contaminants or hazardous materials, and their disposal should be looked at in a much larger context. The safe management of the contaminants and hazardous effluents is a daunting problem in the mining industry and is fraught with technological, economic, social, and political challenges.

Jan 1, 2019

By Jean-Francois Magnan

"The old conventional process to produce lithium raw material dates from 1954 (CA patent #504477A). This process produces low purity lithium carbonate (Li2CO3) only. To obtain battery-grade carbonate, another polishing process is needed. To further obtain lithium hydroxide, another chemical conversion process is needed. That is why historically, the value of lithium hydroxide has always been higher than that of the lithium carbonate precursor. With the old conventional process, the low quality lithium carbonate is precipitated from a lithium sulfate solution (Li2SO4) by adding soda ash (sodium carbonate and its impurities). The resulting reaction produces significant quantities of sodium sulfate (salt cake) as a by-product with amounts larger than the impure Li2CO3 recovered with part of the soda impurities. When this conventional process was invented, the salt cake by-product was not an issue: it was discarded in a river near the plant. This practice cannot be done today in North America. While looking to find a solution for salt cake, electrolytic salt splitting of Na2SO4 into NaOH and dilute sulfuric acid appears as a technically feasible solution to get a rid of the salt cake. However, the sodium sulfate salt splitting process has difficulties to economically compete with the chlor-alkali process, which produces millions of tons of NaOH from sodium chloride (NaCl) every year.In contrast, the process developed by Nemaska to directly produce LiOH by Li2SO4 salt splitting not only solves the environmental problems related to the conventional process to produce lithium carbonate raw material, it also produces very high purity lithium hydroxide monohydrate directly at very competitive OPEX cost in comparison with industry peers (Figure 1). It also drastically reduces the amount of reagent and the direct greenhouse gas emissions."

Jan 1, 2016

By B. S. W. Buffam

"The property of Moneta Porcupine Mines, Limited, consists of a group of eight claims in Tisdale township, Ontario. It includes part of the townsite of the town of Timmins, and adjoins the west boundaries of the Hollin_ger Consolidated and Mace properties. The Moneta property was first staked in 1909, about a year after the first discovery of gold in the Porcupine camp. In 1910 the Moneta Company was incorporated and some preliminary exploratory work performed by Nova Scotia Mines of Cobalt. In 1912 English interests advanced $90,000 for diamond drilling and underground work. One drill hole gave high assays, but apparently the records were poorly kept or the cores were interchanged. As a consequence, when underground exploration was undertaken in 1923 it was directed south rather than west and no ore was found . In 1924 about 5,000 feet of diamond drilling was done in the southern part of the property, but without intersecting ore.In 1931 W. E. Segsworth assumed the direction of the property. Diamond drilling commenced on August 18, 1936. The first hole intersected 9.9 feet of ore averaging 1.23 oz. gold a ton. Underground work was started early in 1937. A mill was erected in the autumn and the first gold brick was poured January 29, 1938.The Moneta mill began operation on January 2, 1938, and the following table gives a summary of the production to June 30, 1943, when the mill was closed."

Jan 1, 1954

By H. Clare Horwood

"Two structures, a fracture zone and a shear zone, contained the two orebodies that yielded all the ore mined at the Gold Eagle mine. The orebodies are known as the Gold Eagle vein and the No. 1 shear zone. Both structures occur close to contacts between Timiskaming sediments, Algoman diorite, and later Algoman granite-granodiorite. The structures were produced by compressive forces from a south direction acting in the southern part of the McKenzie-Gold Eagle stock and in a cylindrically shaped inclusion of Timiskaming sediments.The mine, which exhausted its ore reserves and ceased operations in September of 1941, is on the east side of Mackenzie island, in the centre of Dome township in the Red Lake area.The Gold Eagle vein was located during the summer of 1933 by a surface exploration programme carried out under the direction of Alex Gillies. Sub-· sequent diamond drilling and underground exploration led to the installation of a mill, which came into production in October of 1937. The No. 1 shear zone was discovered and explored later from a drive on the 500-foot level. The mine produced a total of 40,204 oz. gold and 19,157 oz. silver from 223,628 tons of ore hoisted (180,095 tons milled) during its 4 years of mill operation.GENERAL GEOLOGYThe ore-bearing structures trend S.61°E. across Timiskaming greywacke, Algoman diorite, and later Algoman granite-granodiorite. The greywacke is a large, cylindrically shaped mass that is separated from the mai~ mass by the later intrusives. It is a massive, light-coloured, quartzose variety that has been recrystallized by the enclosing granite. The diorite and the granite-granodiorite are early and late components of the McKenzie-Gold Eagle stock. The diorite, which is a porphyritic rock containing large crystals of andesine-labradorite surrounded by hornblende, was injected early in the Algoman period. It was intruded and in large measure surrounded by the later granite-granodiorite. This rock varies from a granodiorite near the mine to a granite in the centre of the stock. All three intrusions are massive and homogeneous."

Jan 1, 1954

By Marcel Vallée

Abstract -Traditionally, samples collected for mineral deposit evaluation have been viewed without explicit reference to reliability, with the illusion that a true value is attainable from a few samples and verifications. For exploration, mineral deposit estimation and production quality control the following definition is proposed: "a sample is a small quantity of material relative to the geological mass it represents, collected according to a systematic procedure, of measurable reliability, from which the grade/quality of the mass which it represents may be estimated, based upon appropriate protocols. This paper will concentrate on the actual rock sampling process. Too often, sample size has been, and is still viewed as a matter of convenience, leaving out representivity considerations, despite the importance of samples on project estimation. Linear samples (chips, channels, drill), panel samples, broken rock or mining samples and very large samples are considered. Collection procedures and quality control protocols to improve the representivity of non-mechanical samples are proposed.

Jan 1, 1998

By D. J. Parker, G. B. Tupper, I. Govender

Positron-Emission-Particle-Tracking (PEPT) has enabled the non-invasive observation of charge and slurry transport in model mills under operational conditions. We use high quality PEPT data to infer that the charge motion can be effectively described by a non-Newtonian granular fluid. An improved theory for slurry transport, including inertial effects, is presented.

Jan 1, 2012

By Paul MacLean

MAC TSM ?Mining and Biodiversity Conservation 1.Corporate biodiversity conservation policy, accountability and communications 2.Facility-Level biodiversity conservation planning and implementation 3.Biodiversity conservation reporting ?Activities indicative of level AA -AAA (formerly 4-5) performance: ?Independent verification ?Integration into broader business strategy and planning processes ?Engagement with communities of interest ?Commitment to actively partner with other organisations for biodiversity conservation

May 1, 2011

By F. Parada L

Two copper concentrate with medium and high enargite content were leached in a 3 L autoclave reactor under conditions based on the CESL process. Copper, arsenic, sulfur and iron were checked in all the experiments and antimony, zinc and molybdenum were evaluated in selected tests. The 98% of the obtained copper extraction is agree with others authors, but the behavior of arsenic, iron an sulfur have some differences. The solid residue was characterized by chemical analysis, DRX and QEMSCAN®. Finally a comparative analysis with neutral roasting as an option for the treatment of this concentrate is done.

Jan 1, 2014

By Chelto. D. Smith

With the pressure on mine and metallurgical managers to take accountability for responsible corporate governance in their operational area, it is no longer acceptable to rely on central departments in the organization to manage safety, health and environmental impacts of the company?s processes. Environmental impacts exist because of the production or mining process. Some of the inputs to the process are natural resources and some of the outputs of the process are the inputs to the environmental control equipment, plant and the environment itself. Environmental management therefore needs to be incorporated in production management to effectively control and reduce the impacts. Many aspects of environmental management are identical to production management and the systems to manage them will likewise be very similar. By examining key components of these two management systems a decision can be made whether environmental management and production management are structurally similar and can be integrated into a combined IT solution.

May 1, 2009