Search Documents

By Neil Schofield

"The Pine Creek gold mineralization is associated with saddle reefs and quartz and quartz sulphide veining within the Enterprise Anticline. The anticlinal structure is complex and the mineralization was considered prior to development to be dominantly strata controlled. Gold grades vary up to 160 gin 1.5 m core samples with coefficients of variation in excess of three.The estimation of ore reserves for such a deposit must account for both the geological complexity and the extreme variability of gold grade.This paper describes the structural and variogram analysis of the gold grades and demonstrates the importance of incorporating the geological model in such an analysis. Variogram interpretation is greatly improved and greater insights into the finer geological structure areprovided. Part 2ofthis work presents the application of multigaussian kriging to reserve estimation for deposits with highly variable grade and which consequently demand highly selective mining operations. IntroductionThe Enterprise Gold Mine is situated some 220 km southeast of Darwin in Australia's tropical north. Gold is believed to have been discovered there in 1869 during the construction of the overland telegraph line.From 1894to 1915, some 75 000 ounces of gold were produced from 121 000 tonnes mined mainly by Chinese leaseholders. From 1906 to 1915, government-sponsored drilling led to the sinking of the Enterprise Shaft to 79 m and several drives were developed. Mining ceased because of war.Since late 1980, Goldfields Exploration Pty. Ltd. had explored on several mining tenements near Pine Creek under joint venture with the title holders, Enterprise Mines NL. This work culminated in the development of the current mine which opened on October 29, 1985.Feasibility studies to determine the economic viability of mining were based on ore reserves generated by project geologists using a sectional polygonal approach tuned to the interpreted geological control of the mineralization.The study motivating this two-part paper covers are-estimation of the recoverable reserve s using the geostatistical approach of multigaussian kriging developed at Stanford University, (Verly, 1984)."

Jan 1, 1988

By E. Engelbrecht

"A pressure non-oxidative leach is employed at Anglo American Platinum Base Metal Refiners to extract nickel from a slow cooled matte. The design base requires two 80 m3 autoclaves in parallel to achieve a nickel extraction of 60% at the nameplate capacity of 32.4 ktpa nickel plated. Isothermal modelling of mineralogical and chemical concentration profiles, through a reactive mass balance, permitted rate constant parameter estimation and selection of the most probable reaction pathway. The model was validated with plant data up to a capacity of 26 ktpa Ni plated and suggested by extrapolation that nameplate capacity may be viable through one 80 m3 autoclave.INTRODUCTION Anglo American Platinum Base Metal Refiners is situated on the outskirts of Rustenburg in the North-West province of South-Africa. The refinery produces nickel cathode, copper cathode, cobalt sulphate powder, covellite rich copper pressure leach residue and bulk sodium sulphate through an integrated circuit that refines slow cooled converter matte. The converter matte is milled, non-magnetics are separated as solid nickel copper matte (NCM), and the magnetics are leached yielding a pressure vessel liquor (PVL). The remaining solid platinum group metals (PGM) concentrate after leaching is sent for downstream processing in the Precious Metals Refinery (Hofirek & Kerfoot, 1992). The work presented here is applicable to the base metals refinery which receives the two base metals feed stocks NCM and PVL. In 2009 the capacity of the refinery was upgraded from 21 ktpa nickel cathode plated to 32.4 ktpa. This paper deals with evaluating the capacity of the pressurised non-oxidative nickel leach (NOX) process which accounts for at least 28% of the nickel leached from NCM by design. The NOX design base requires two 80 m3 autoclaves divided into four compartments operated in parallel at 155°C and 600kPa(g). Elevated temperature is required to speed up the leach kinetics of particularly nickel and iron which are trapped in slow leaching mineralogical phases namely millerite and bornite, (Dinham, 2006). The stated equivalent capacity for the NOX configuration was 32.9 ktpa nickel plated at first pass nickel and iron leach efficiencies of 60% and above 80% respectively and is a key step for the selective removal of iron (Bryson, Hofirek, Collins, Stiksma, & Bereaowsky, 2008)."

Jan 1, 2017

By C. Harold Riches

This article is directed co a commentary on the patent system in its relation to the public interest. As man gained supremacy over his environment, he could devote progressively increasing portions o his time to improving his standards of living. In the history of the human race, we have advanced from the hollowed floating log to the modern steamship of the present age; from the sickle and flail to the reaper and combine; from the trumpet and drum as a means of communication co the telegraph, telephone, and radio; from the horse and ox cart to the automobile, truck, aeroplane, and train; and so on ad infinitum through the list of inventions on which are based the industrial and political economies and standards of living we enjoy today. It has also been a long road from the day of the alchemist and his closely guarded secrets to the era of the patent system and its storehouses of knowledge open to the world. The alchemist and the craft and merchant guilds closely guarded their secrets. In fact, they largely opposed innovations on the grounds that they might injure profits and restrict employment. In these days of unrest, with great clamour out of doors for radical changes in our political and industrial economies, it may not be untimely to examine one of the keystones which support the economic structure we know as the free enterprise system, the system which is predicated upon the right of the individual to own property. Many, through impractical idealism, ignorance, confused thinking, or blind political prejudice, advocate the substitution of ownership by the State ? for the right of ownership by the individual. As civilization has advanced to the high standards of living we enjoy today through the efforts of a comparatively few inventors, the patent system which has provided the incentive that created the inventions on which our industries and our employment are based is fully understood and appreciated by a comparatively small percentage of our people. As a result, the patent system, as a keystone in our free enterprise economy, is an apt target for destructive criticism, with the thought, possibly, that by eliminating or drastically restricting the several rights to individual ownership one by one, ownership by the State will progressively replace ownership by the individual.

Jan 1, 1949

By J. A. McLennan, J. M. Ortiz

Nickel laterite deposits are typically formed from tropically weathered mafic-to-ultramafic complexes. The resulting nickel concentration is found within soil horizons and is mineable with regular dozer units. At the time of mining, digging elevations are needed at selective mining units (SMUs) or representative dozer regions (RDRs). Moreover, for mine planning, the costs due to dilution and lost ore require mining elevations to be specified. A conditional simulation approach is used to calculate “optimum” RDR mining elevations. Multiple realizations of the ore base surface are simulated. For a single bottom surface realization, dilution and lost ore costs are calculated over the entire vertical extent of each RDR. The optimum mining elevation is the elevation where the lowest summed cost of “accepting dilution” and “wasting ore” occurs. The reported RDR dilution is the cost of mining the volume of waste located below the bottom surface and above the optimum mining elevation. The reported RDR lost ore is the cost of not mining the volume of ore above the bottom surface and below the optimum mining elevation. For all ore bottom surface realizations, optimum RDR mining elevations and their associated dilution and lost ore costs are calculated and compiled to represent production uncertainty.

Jan 1, 2006

By F G. Cooke

"This paper describes a medium-sized copper mine's results in making innovations and changing operational practices to combat increasing expenditures due to higher labour and supply costs, extended workings, scarcity of experienced manpower and problems created by deteriorating ground conditions.OPEMISKA COPPER MINES (QUEBEC) LIMITED is located at Chapais in the Chibougamau area, in central eastern Quebec, approximately 300 miles north of Montreal and 150 miles north west of Lake St. John. The latter area, developed by lumbering and farming, has supplied the majority of the employees, who, with training and experience and a desire to work and improve themselves, have become the backbone of the Company's 600 personnel.Opemiska began production in 1954 at a rate of 400 tons per day, using diesel power and road transportation. The rate was progressively increased and, by 1959, with hydro-electric power and rail transportation, the mine had reached its present production rate of 2,000 tons per day. It has produced concentrates containing over 430 million lbs of copper."

Jan 1, 1968

By H. Karakul

Determination of P-wave velocity (Vp), which is closely related to intact rock, is a nondestructive, easy and less complicated procedure. Due to these advantages, there is an increasing trend to predict the geomechanical properties of rocks from Vp. In addition to mineral content, cementing material and porosity, degree of saturation (Sr) are also other factors influencing geomechanical properties of the intact rock. However, up to the present, in the studies on the prediction of geomechanical properties of rocks from Vp, the effect of Sr has not been investigated. By considering this issue, in this study, it was aimed to correlate strength properties (uniaxial compressive and tensile strengths) and Young’s modulus with Vp of various rock types under different degrees of saturation. In addition, geomechanical properties of rocks were estimated from theoretical P- and S-wave (Vs) velocities, which were calculated based on their mineralogical compositions. For this purpose, fourteen different rock types were collected from several parts of Turkey and a comprehensive laboratory testing program was conducted. In the statistical analyzes, a series of different prediction relationships were developed by using independent variables such as Vp, Sr and effective clay content (ECC). Simple regression analysis results indicated that although prediction of the geomechanical properties of rocks from Vp at different degrees of saturation was possible, the equations developed would yield some under- or over-predictions. On the other hand, the multivariate equations developed have very high prediction performances and are very useful tools to estimate the geomechanical properties from the measured Vp at any Sr value. In addition to mineralogy, the variation in geomechanical properties with increasing Sr is also associated with the combined effect of porosity and clay content, which is first described in this study by the term Effective Clay Content (ECC). It is also noted that strength properties of rocks at any Sr may also be estimated using the empirical relations based on the theoretical Vp and shear-wave velocity (Vs) values, which are calculated from their mineralogical compositions.

Jan 1, 2015

By Baoquan An

The energy required to fragment a rock is proportional to the increase in the fracture surface area and hence is proportional to the rock?s surface area. In comminution, the slope of the linear relationship between size reduction ratio and specific energy is usually defined as grindability. Another definition of grindability based on newly created specific surface area and specific energy is introduced. The two definitions for grindability reflect the grindability properties of rocks and can be used to measure of the efficiency of mills or crushers. The feed particle size distribution influences the energy needed to comminute the rock. For a given ratio of average feed size to product size, the smaller feed size requires more energy.

May 1, 2004

By Ken Norris

"Campbell Mine which has been in continuous operation since 1949 has undergone numerous operational changes in the past 3 years. This paper describes the process changes which have occurred at the Campbell Mill since 1991. The paper discusses the engineering, construction and startup of the effluent treatment circuit, the new oxide filtering and merrill-crowe precipitation circuit, and the changes to the pressure oxidation circuit. Particular attention is paid to startup problems and solutions to these problems. A review of the benefits and results of these process changes is also discussed. Future changes are also briefly reviewed with anticipated goals and expectations.IntroductionCampbell Mine is a gold mine 100% owned and operated by Placer Dome Canada. It is located in Balmertown, Ontario which is located 300 kilometres northeast of Winnipeg, Manitoba. The Campbell Mine has been in continuous operation since 1949, producing nearly 8,000,000 ounces. In 1993 Campbell Mine is budgeted to produce 289, 750 ounces of gold at a cash cost of $157 US/ounce. Daily mill tonnage is budgeted for 1,430 tons/day but has milled as high as 1,600 tons/day on a consistent basis. Recovery in 1993 is 93.4% and is budgeted to average 94.5% in 1994.In the 1992 edition of the proceedings of the Canadian Mineral Processors conference I described the changes that were made at Campbell starting in 1989. This paper continues where the 1992 paper ended and discusses the changes to the Campbell mill since that lime. The changes to Campbell since January 1992 have been numerous with capital expenditure in the mill exceeding $14.1 million. This paper describes three primary projects since that lime: the effluent treatment project ($5.5 million), the oxide leach/filtering and merrill-crowe project ($4.6 million) and the pretreatment project ($2.81 million). The focus of this paper is to highlight the justification of each project, the design and engineering, and some of the initial operational problems and solutions applied to those problems."

Jan 1, 1994

By Carmen Mihaela Neculita

Sulfate-reducing passive bioreactors efficiently treat acid mine drainage (AMD) by increasing its pH and alkalinity and by removing metals as sulfide precipitates, in addition to hydroxides and carbonates. However, the new mining legislation sets discharge limits based on physicochemical parameters and on the non-toxicity of treated effluent as well. In this study, toxicity was assessed for effluent from 3.5 L column bioreactors filled with mixtures of natural organic carbon sources and operated at two different hydraulic retention times (HRTs) of 7.3 d and 10 d for the treatment of a highly contaminated AMD. Acute toxicity was observed for D. magna, and a toxicity identification evaluation (TIE) procedure was performed to identify potential toxicants. To help the interpretation of the toxicity results, metal partition in the effluent was also determined by filtration and ultrafiltration, while geochemical modeling was performed for metal speciation evaluation. The 10 d HRT effluent was nonacutely lethal for rainbow trout but acutely lethal for D. magna, whereas the 7.3 d HRT effluent was toxic for both organisms. The toxicity to D. magna was eliminated by 2 h of aeration for the 10 d HRT effluent, and the TIE procedure suggested iron as a cause of toxicity. However, the 2 h aeration eliminated the toxicity of the 7.3 d HRT effluent, only if performed after the pH rising to 9.3. Data regarding metal speciation indicated instability of both effluents during aeration and were consistent with the toxicity being caused by iron. The study indicates that design of passive treatment should include sufficient HRT and posttreatment aeration to meet acute toxicity requirements. Keywords: acid mine drainage, sulphate-reducing passive bioreactors, hydraulic retention time, effluent toxicity, metal speciation

Nov 1, 2008

By Laura Mottola

This paper outlines a framework for ensuring the success of the implementation phase that follows research and development of new mining technologies and systems. It is based upon recent and past lessons learned that have demonstrated the critical challenges to effective technology transfer, which frequently receive inadequate attention within the culture of the mining business. The paper focuses on mining automation implementation challenges and then outlines a Roadmap which is proposed as an integrated framework to deal with the key aspects of people, process and technology. This framework is built upon: assembly of a Strategic Team to develop a Roadmap; fully understanding the business requirements of the technology initiative; defining Key Performance Indicators in a Balanced Score Card; performing a Stakeholder Analysis to identify the affected groups; and finally developing a master Project Plan to execute the Roadmap.

Oct 1, 2009

By Jean Dugas, Roger Sirois

The Mineral Deposits Service of the Quebec Department of Natural Resources is engaged in the preparation of metallogenic maps as a contribution to the Canadian Sub-Committee of the Metallogenic Map of North America. The preliminary work is being done on large-scale maps. The main objective is to clearly represent information on ore deposits in a suggestive way. The design of the legend to meet these requirements is discussed. As these maps are still only descriptive, a further step will be the interpretation of data into metallogenic maps with Jess emphasis on the individual deposits and more on the metallogenic factors. Both types of map should prove useful in the search for ore deposits; the first by providing at once a large amount of information, the second by suggesting the ore controls.

Jan 1, 1967

By Thom Sedun

No sector of the mining industry is more closely tied to local communities than aggregates. Noise, dust, traffic, visuals aesthetics and environmental impacts all fall under the purview of neighbours, local governments and nongovernment organizations. It is no surprise that aggregate operations may not be welcome neighbors in many communities. In British Columbia (BC), the regulatory environment for aggregate operations includes a local component of municipal bylaws and land use-planning in addition to the usual suite of federal and provincial statutes that apply to its sister mining sectors. Additionally, under common law aggregate extraction is not considered to be a land use subject to land use zoning, and some aggregate processing activities can be regulated by zoning. Often traversing multiple local government jurisdictions, aggregate producers find themselves negotiating not only local traffic, but also a mosaic of regulatory environments. There is an opportunity in this present situation to facilitate the application of current technology and practices in the mitigation of many community and environmental concerns associated with aggregate operations. Moving a bulk commodity is a volume-based business, and operators often don?t have time for matters that don?t directly or obviously affect the bottom line. Regulatory agencies often play multiple and complex roles with respect to their industry, not the least of which is the fiduciary role. Balancing how and when to assist an industry is often a difficult decision. For the aggregate industry in BC, the Ministry of Energy and Mines saw an opportunity to assist not only aggregate operators, but also regulatory agencies, local governments, and the general public. Through investing in the Aggregate Operators Best Management Practices Handbook (handbook) project, the Ministry of Energy and Mines (MEM) believes that it will realize a return of upheld community values, enhanced environmental protection, improved regulatory compliance, reduce disputes and a stronger provincial aggregate industry. It is the intent to publish the handbook electronically through the MEM website later this year.

May 1, 2002

By S. Sillitoe

In mining, as in other business and engineering enterprises, efficient operation depends upon how well and how quickly the lines of communication can function. Mines have used the telephone on and between levels for many years, but in the hoisting shaft maintenance of physical wire connections for communication with the moving cage or skip has been found, for all practical purposes, impossible. A most natural solution was, therefore, the code-bell or buzzer signal system between fixed levels, and this has been standard practice throughout the mining world for many years. However, this system has serious limitations which make it impossible to signal a cage between levels in the shaft, and it requires crude, hazardous or costly methods for signalling during daily shaft inspection. Radio signalling overcomes these difficulties, because the communication medium is never broken and the cage-tender or shaft inspector can safely signal to, and receive signals from, the hoistman at any time from any position in the shaft, whether stationary or in motion. In addition to both audible and visual code signalling, two-way telephone communication and slack cable alarm are facilities made possible in recent commercially developed equipment.

Jan 1, 1949

By Horatio Sam-Aggrey, Margot Hurlbert

Small Modular Reactors (SMRs) have been touted as having the potential to spearhead a nuclear renaissance. Proponents of this view cite the relative advantages of SMRs over larger nuclear plants as reason for their optimism. Some of these merits include potential economies of mass production deriving from modular factory production, enhanced safety features, the ability to locate reactors in remote areas, and reduced requirements for technical workforces to install and maintain SMRs. Despite the optimism surrounding SMRs, nuclear power is still a contentious issue for many Canadians. The growth of nuclear power remains adversely affected by concerns over issues such as: the health and safety consequences of nuclear power generation, environmental impacts, proliferation of nuclear materials, terrorism, and radioactive waste disposal (Organisation for Economic Co-operation and Development (OECD) and Nuclear Energy Agency (NEA), 2010). Personal values, past nuclear accidents, and lack of trust in the industry are other factors influencing attitudes toward nuclear energy (IAEA, 2005). In Canada, three main areas where SMRs could be used have been identified. These include: a. Traditional, on-grid power generation, especially in provinces looking for zero-emissions replacements for CO2-emitting coal plants. B. Remote off grid communities that currently rely on diesel or fuel oil power generation. There are 279 off-grid communities in Canada, many of them being Aboriginal communities (NRCan, ND). Notably, all communities in each of Canada’s three territories qualify as remote. C. Resource extraction sites, such as mining and oil and gas extraction sites. Many of Canada’s principal producing mines and active mineral exploration projects are located within close proximity of Aboriginal communities. Any proposed implementation of small nuclear plants would, require the support of the local population, which is largely Indigenous in the northern regions. The possible deployment of SMRs raises important issue relating to consultation and accommodation of Aboriginal concerns regarding potential SMR deployment. This is especially pertinent given Canada’s pending implementation of the provisions of UNDRIP. One of the provisions of UNDRIP that has attracted a lot of attention is the one on Free Prior and Informed Consent (FPIC). Drawing on previously published information, this paper discusses some of the challenges posed by FPIC for the deployment of SMRs. The next section outlines the provisions of FPIC and its implementation in the Canadian context. Section 3, details some of the challenges posed by FPIC to the deployment of SMRs, while Section 4 provides some concluding comments.

Jan 1, 2020

By M. Imamura

Sumitomo Metal Mining Co., Ltd. has developed a novel hydrometallurgical process for producing not only copper metal but also iron metal from copper concentrates. Because copper concentrates generally contains the same amount of iron as copper, cost-effective rejection of the iron is a key issue for the development of the process. Conventional hydrometallurgical processes produce a large volume of goethite or hematite for disposal and the residues are not environmentally friendly. In the novel Sumitomo hydrometallurgical process, copper is leached effectively from chalcopyrite concentrates using chlorine gas, followed by purification through solvent extraction and electrowinning for copper and iron recovery. This process has many advantages such as the minimization of the volume of solid waste by the recovery of metallic iron and the production of high purity copper. Iron metal with a purity of more than 98% can be recovered from the purified raffinate. This paper presents the results of the batch and continuous tests of the process flowsheet.

Jan 1, 2006

By D. M. Bastidas

The reduction of copper sulfide and copper oxides originated during artificial tarnishing of copper was studied using potentiodynamic potential/current density experiments. Six copper surface treatments were considered: mechanical polishing; indoor exposure for 7 days; chemical etching in 1.6 M nitric acid; chemical etching and heating at 160°C; and chemical etching and dipping in a 9x10-4 M or 0.9 M potassium sulfide (1(25) solution at 70°C. Cuprite (Cu20) and chalcocite (Cu2S) were the main compounds formed. A linear relationship with the square root of the scan rate (v) was obtained by plotting the potentiodynamic potential/current density for the tarnish dissolution processes. A relationship between potential and current density cathodic peaks was not obtained, according to Müller's model, showing a proportionality factor with the dimensions of a resistance.

Jan 1, 2007

By A. Todd Davis

"Introduction“CAN YQUR Company afford not to train?"" This question was asked by Jack Taylor in the Factory Management Magazine for June, 1950. Mr. Taylor went on to say, ""No, it can't; no Company can"". It's true that many training programmes have not done the job they were designed to do because of a number of factors such as parts of management resenting training, management failing to understand the abstract values of training, and management giving impossible assignments or picking the wrong trainers. However, Mr. Taylor summarizes his article by saying that a properly-designed and •conducted training programme brings a company or a corporation to the point where the question is: ""Can my Company afford not to train?""About two years ago, in July, 1952, Nevada Mines Division of the Kennecott Copper Corporation embarked on a training programme, the same type of programme that had been inaugurated earlier at the •Utah Copper Division at Bingham, Magna, and Garfield, Utah. President Charles Cox of Kennecott, in •a speech made •before the Utah Bankers Association in June of 1951, stated that, ""I think that our programme of employee training is one of the most important phases of our entire operation"". That statement might be said to be one of the guiding principles of training at Nevada Mines Division. Training is supported by top managements and down the line to Division managements. As the years go by, the Company expects to receive many benefits from training."

Jan 1, 1954

By Blaycock. S. C.

WE should indeed feel proud and satisfied with the accomplishments of our great mining and metallurgical. industries during the past quarter of a century, for they have vastly exceeded those of any previous period of like duration. 1 feel that Canadians, and particularly those in the mining industry, should know more concerning the important role our industry will be called upon to play in the present war. Our Empire metals will be an outstanding factor in this conflict. Every man connected with the industry, from the lowest paid labourer to the highest official, can feel proud that his every effort results in more and more production of those metals which will help to give the Empire supremacy. He can feel assured that, by sticking to his job and by putting his whole heart into his work, he is making a contribution towards winning the terrible struggle in which our Empire and our gallant French allies are engaged. These two great peoples will have ro bear the brunt of the task of ridding the world of the menace of those who would set up force. and might in the place of right and justice in the settlement of international affairs. As the present European crisis developed, it became evident that they, alone, would have to accept the challenge and fight the enemies of Democracy to ensure the survival of the small nations of Europe and, indeed, of the great democratic powers themselves. The acquisitive eye of the German leaders had looked far ahead and they had realized that the eastern European states, already reeming with population, were no solution to Germany's space problem; but they thought that these states could be gobbled up one by one, each in turn strengthening Germany's might until it could successfully challenge France and England. No glimmer of doubt dimmed their vision. The two great democracies once subdued, they could proceed to seize Canada and the United States. This clone, they would have an abundance of room to expand, as well as those resources-grain, timber, cotton, nickel, iron, lead, zinc, copper, gold, silver, sulphur, oil-which German statesmen have always coveted. Von Ribbentrop, von Alvensleben, Bernstorff, and many others have made exhaustive studies of our resources. German rulers had been told that the French would not fight and that the British could not. They knew of the rust on the British war machine. There was no cloud in the sky; their fond dream was at last robe fulfilled.

Jan 1, 1940

By Albert W. Scragg

"THE ADMINISTRATION DEPARTMENT consists of six sections, all with their own supervisors, reporting to the superintendent of administration. Although each of these sections is uniquely separate, they all work together, in one department, to provide very necessary services.1. Accounting 2. Purchasing 3. Warehousing 4. Data Processing 5. Inventory Control6. Office ServicesThis department, which now numbers 108 people, had its birth in an office over a hardware store in downtown Timmins in 1964. Initially, only basic accounting and purchasing functions were performed and these, of course, were on a very small scale. The growth of the administration department is a function of the growth of the company."

Jan 1, 1974

By B. W. Williams

The crack propagation behaviour of Zr-2.5Nb pressure tube material was studied through comparison of the measured behaviour with the predicted response from finite element analysis. Three-dimensional finite element simulations of compact tension specimens were performed using the crack tip opening angle as a fracture criterion to allow for crack propagation. To obtain reasonable agreement with the measured behaviour, it was important to capture both the anisotropic plastic deformation behaviour of the Zr-2.5Nb material through use of the Hill-48 yield criterion and damage due to void growth, nucleation, and coalescence through the use of a Gurson-based constitutive model in the simulations.

Jan 1, 2010