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By L. G. Bergh

The experience developing a supervisory control and information systems in a SX pilot plant is presented. The plant is located at the Process Control Laboratory, Santa Maria University, in Chile. In this work, the problem of controlling this process is discussed and related literature is briefly reviewed. Then, an innovative control scheme organized in three levels, local, hydrodynamic, and metallurgical supervisory controls is presented in an architecture including field controllers, PLC, and PC networks. Operating decisions in the metallurgical supervisory control are taken with incomplete information from on-stream analyzers. The control proposed is based on metal and acid concentration predictions of intermediate and exiting streams through the use of dynamic and static models and flow rates and input concentration measurements. Preliminary results are presented. The main objectives are to develop and test intelligent techniques in a hybrid system, and to study measurement and supervisory control problems. It is expected to produce reliable results that will contribute to improve the efficiency of this emerging and important process.

Jan 1, 2007

By David G. Dixon, Ahmad Ghahremaninezhad, Edouard Asselin

"Atmospheric leaching of chalcopyrite in sulfuric acid solutions is a slow process due to the mineral’s passivation. We have investigated the nature of the passive film in this work. Electrochemical reduction and oxidation of chalcopyrite over the potential range of -0.5 to 1.2 VSHE were investigated in 0.5 M sulfuric acid solution (pH 0.3) at 25 ºC by multicyclic voltammetry and open circuit potential measurement. The influence of scan limits on the evolution of current peaks was studied with both stationary and rotating electrodes. It was observed that the anodic oxidation of chalcopyrite begins at potentials above 0.6 VSHE, most likely by preferential dissolution of iron atoms over copper atoms. The selective electro-dissolution process results in formation of a metal-deficient sulfide passive film (i.e. Cu1- xFe1-yS2, y > x). The passive film dissolves at 0.9 VSHE. Elemental sulfur is one of the products of chalcopyrite dissolution above 1.0 VSHE. Cathodic reactions within the potential region of 0.1 to 0.6 VSHE and anodic reactions at potentials lower that 0.5 VSHE are associated with at least one soluble species from solution. The soluble species involved in the cathodic reactions are likely ferric and cupric, while the soluble species involved in the anodic reactions is likely H2Saq."

Jan 1, 2014

By P. Roman, L. Daneshmend

"During the last decade, mining companies have been overwhelmed by technological solutions to perceived problems. This is particularly true with information technology where rapid advances have resulted in a professional climate characterized by technomania — the perception that failure to adopt emerging technologies will result in a loss of competitive advantage. This paper describes the applicability of structured analysis and design techniques as an appropriate methodology for integrating emerging technologies in the mining industry. The potential of this approach to improve overall mine effectiveness through improved communication and co-ordination between operations and maintenance is discussed. IntroductionA strong working relationship between the operations and maintenance departments in both open pit and underground mines is fundamental to the overall success of the mining endeavour. Unfortunately, for many mines, this characterization is far from accurate. Short-range production targets dominate the day-to-day management of the mines. This can be seen in Bostwick and Buchanan’s (1993) report on American Barrick Resources efforts to achieve an aggressive 415 000 tpd mining program at their Goldstrike operation in Nevada. When production managers do not meet their quotas, the finger is often pointed at maintenance. As a result, a confrontational culture can develop between the two organizations, resulting in a lack of cooperation that exacerbates the problem. Historically, production planning has taken priority over maintenance planning. This is reasonable since production is the primary purpose of the mine with maintenance serving in a support role. This basic relationship remains intact today. However, the trends toward mechanization, increasing levels of automation, and larger equipment, have resulted in increased reliance on the equipment used in the mine. As a result, downtime costs now go well beyond the direct labour associated with the repair of the machine. Lost production costs due to downtime resulting from failed equipment are becoming an increasingly important factor in determining a mine’s overall economic performance."

Jan 1, 2001

By P. L. Claessens, S. Belisle, C. Bowen

"Use of zinc shot feed is a well-established procedure among North American electro-galvanizers. This form of zinc is easy to handle and relatively inexpensive when compared with zinc oxide. This paper reports results on the kinetics of zinc shot dissolution in traditional pure zinc solutions and in electrolytes used for the plating of nickel/zinc alloys. Despite the cementation of minor amounts of nickel in the latter solution, acceptable dissolution rates of the zinc shot can be achieved through proper adjustment of the solution velocity. Under these conditions, the nickel shell produced by cementation is continuously abraded, exposing the underlying zinc.IntroductionThe use of insoluble, noble metal-containing anodes rather than soluble zinc anodes for the operation of high current density electro-galvanizing lines has gained almost universal acceptance. Two major reasons for this trend are:• improved control of the process by virtue of constant inter-electrode distance; and• increased productivity because the operation of the lines does not require the relatively frequent interruptions for replacement of consumed anodes .The results of the principal anode and cathode reactions are, respectively, depletion of the zinc content of the electrolyte and the increase on its acidity;"

Jan 1, 1991

By Ross D. Lawrence

"IntroductionOne of the methods used when applying the Market Approach to the valuation of a mineral exploration property is known as the Joint Venture Terms Method. The method is particularly useful for the valuation of early-stage exploration properties. Unfortunately, valuators are sometimes imprecise in distinguishing between joint ventures and other types of transactions.At VALMIN '94, Bob Appleyard1 proposed that, if one ignores the time value of money and the probability that the expenditure commitment would be completed, the formula to calculate the value ($V) of a property owned by Party B at the time of the deal would be:$V =$Ex (100-1%)/1% (Formula I)Where $V is the value of the property2Where $E is the expenditure commitment by Party A, andWhere 1% is the percentage property interest to be earned by party A.At PACRIM '99, Mike Lawrence and Graham Dewar3 referred to this method and suggested that there was an ambiguity in the formula proposed by Appleyard in 1994. Mike Lawrence referred to this problem again at VALMIN '014•Lawrence & Dewar suggested that the formulashould be:$V100% =($Ell%) x 100 (Formula 2)Where $V 100% is the value of the entire property,Where $E is the expenditure commitment by Party B, andWhere 1% is the percentage property interest to be earned by Party B.Subsequently, there has been considerable discussion in the AuslMM Bulletin5. In my view, this discussion has touched on a number of useful points, but generally has overlooked one essential element needed for an understanding of the correct application of the N Terms method. That essential element is to understand that there is a material difference between (1) entering into a joint venture arrangement and (2) the purchase of an interest in a property."

Jan 1, 2003

By I. Filzwieser, A. Filzwieser

The Peirce Smith converter is the key metallurgical vessel in the majority of copper smelters. During the two step process, oxygen enriched air is injected through a row of tuyeres into the matte received from a primary smelting unit. Additionally, in the first step the iron content is oxidized into a fayalite slag by the addition of silica. During the second step, the remaining copper sulphide is converted into blister copper with a final sulphur content of approximately 200 ppm. The overall efficiency of this process is determined by the total reaction time, the slag quality and quantity, and the chemistry of the final blister copper. To increase the reaction kinetics during both stages, the METTOP Process Control and Regulation (MPCR) system was developed, which consists of four elements: OPC - Optical product control ACR - Automatic computer regulation GCU - Gas control unit GIS - Gas injection system The OPC system from SEMTECH records the optical spectrum emitted by the off gas flame providing immediate, detailed process information. Using this online data, additional gas can be automatically injected into the converter through a gas injection system opposite the tuyere zone. An improved oxygen distribution in the melt and the accurate determination of the process end point results in a significant reduction in the process cycle time. Furthermore, by maintaining the reaction closer to the equilibrium the final sulphur and oxygen content can be reduced compared to the conventional process. In particular, the final sulphur content can be lower than 70 ppm, eliminating the need for an oxidation step in the anode furnace.

Jan 1, 2007

By G. F. Doggett

In describing accounting methods at Lake Shore Mines, it is the intention of the writer to limit the discussion to the principal features of the system used in securing cost figures and other statistics. The subject can be conveniently treated under the following divisions: (1) Time-keeping and Labour Distribution (2) Supplies: Handling and Distribution (3) Method of Assembling Data for Cost Purposes (4) Details of Operating Costs Time-Keeping and Labour Distribution After a new employee has gone through the routine of being 'hired on', he is assigned an employment number corresponding with the group applying to his occupation. This is for identification purposes in the plant and time office. He is also given an individual serial number, the use of which will be refer-red to later. On entering and leaving the plant, each employee passes through the clock room adjoining the time office, where he registers the time in and out on time recorders, on the clock card (Figure 1) bearing his name and number. It is the duty each morning of the time clerk to extend the hours worked by each employee, as indicated by the clock for the previous day, and at the end of the half-month period the total hours are multiplied by the rate and entered in the space provided for total wages at the bottom of the card.

Jan 1, 1935

By Robert B. Parsons

"For the fourth time in five years, residents of northern Canada have seen a change in the tax treatment of housing and travel costs. The latest changes announced in December 1990 by the Minister of Finance are to become effective in 1991. When will the tinkering stop?IntroductionFor man y years prior to 1987, certain travel and housing allowances received by employees in remote areas were generally considered by Revenue Canada to be tax-free, even though some observers suspected that such generous treatment was contrary to the provisions of the tax legislation. In the mid-eighties, Revenue Canada decided to reconsider the tax treatment of the mining industry's long standing practice of providing housing and travel assistance to these employees. The tax- free treatment was continued by virtue of annual remission orders, but only pending the enactment of legislation which would tackle the issue head-on and layout the rules in black and white to be seen by all. The sequence of events since then may be chronicled as follows:February 26, 1986-Finance Minister Wilson's budget present s the framework for the future tax treatment of travel and housing benefits provided to residents in remote regions of Canada.December 22, 1986-The Minister of Finance announces detailed rules to fill in the earlier announced framework.January 1, 1987-The new tax rules come into effect.April 29, 1988-The Minister of Finance announces the establishment of a Task Force to examine the existing criteria for determining the eligibility of residents of northern and isolated areas for tax benefits.October 27, 1989-The Task Force presents its report.December 7, 1990-Finance Minister Wilson announces a new system of tax benefits for residents of Canada's northern and isolatedregions.January 1, 1991-The new rules become effective."

Jan 1, 1991

By Raymond Dallaire

The Humphrey's spiral is a static gravity separation device which cannot be adjusted to match short-term variations that occur in the feed. Any disturbance in the feed grade, per cent solids or flow rate affects substantially the recovery and grade of concentrate. Such variations must be minimized in order to maintain the desired rate of production and quality of the product for which the installation has been designed. A study has been performed in which the foregoing assertions were quantified. The feed grade, per cent solids, flow rate and particle size were varied independently. Ore from Carol Lake, Nfld., was used throughout the experiments. This consisted of specular hematite and magnetite in a silica gangue.

Jan 1, 1978

By Nick Vayenas

This paper discusses the application of a commercially available state-of-the-art PC discrete-event simulation modeling software, called Promodel, for simulating a typical underground mine hoist system in the Sudbury mining region, in the province of Ontario in Canada. The reasons for using Promodel as a two-dimensional simulation development tool is its simplicity in use and its capabilities to provide enough flexibility to meet the modeling requirements of a mine hoist system. General information of a mine hoist system was collected for building the model. Example of the model?s output is also presented. The application of Promodel in underground mining offers a powerful, two-dimensional simulation environment in an affordable price for mining engineers to analyze and study operational problems. This hoist simulation model is an intuitive demonstration of the mine hoisting elements and the operational logic of the hoist, based on which optimization of the entire mine system materials flow can be considered as part of a mine cycle management feasibility study.

Oct 1, 2009

By S. Litke

Elemental sulfur was stockpiled at the Mount Polley Mine for use as a source of sulfuric acid as part of research into leaching copper from oxide ores, but the project did not proceed beyond an initial pilot- scale evaluation. Since placement, the sulfur has oxidized and some sulfuric acid leached into the underlying rock. The reaction of the acid with these underlying materials has been studied as part of an evaluation of the effects of leachate from the pile. The rock underneath the sulfur pile is composed dominantly of primary and secondary alumino-silicates with less than 1% carbonate (calcite) and iron sulfide (pyrite). In its unaltered condition, the rock is classified as non-acid generating. Conceptually, it was expected the sulfuric acid would be neutralized by the rock to varying degrees resulting in a series of pH-controlled weathering fronts progressing from leached near the contact with the sulfur pile (pH <3), to active neutralization by silicates (pH 4–5), to active neutralization by carbonates (pH >7). The rocks underneath the pile were sampled to determine the extent to which the rocks had reacted and their long-term stability after removal of the acid source. INTRODUCTION When rock is blasted and excavated to facilitate mining ore, it is typically placed and stored on the surface in piles. The resulting drainage may have a neutral to basic pH (i.e., non-acidic drainage) or a low pH (i.e., acid rock drainage, ARD) depending on the mineralogy of the rock being stored in the piles. Acid- base accounting (ABA) can be used to characterise the two types of rock: potentially acidic drainage generating (PAG) and not potentially acidic drainage generating (NAG) (Price, 2009). According to Price (2009), NAG is defined as having an excess of neutralization potential (NP) in the rock in the form of calcium carbonate-like minerals when compared to acid potential (AP), i.e., a Neutralization Potential Ratio (NP/AP = NPR) greater than 2.0, whereas PAG is classified as having an excess of AP (i.e., an NPR less than 1.0). This is a conservative estimate and may be slightly modified depending on the mineralogy at specific mine sites. Rock with an NPR of 1–2 is also capable of generating acid (Price, 2009) and, depending on the mineralogy, may also be classified as PAG. Drainage from PAG material can generate acid immediately, or many years after it has been exposed to surface conditions. Disposal techniques depend on the category (i.e., NAG or PAG) and reactivity of the rock stored in the piles.

Jan 1, 2019

By D. Fodor

In Romania, there are significant lignite and brown coal reserves hosted by different regions of the country. The most important lignite bearing zone of the country situated in the North ? West part of Oltenia region and which covers a surface area of 2,500 km2 and host a total reserve of 3.0 billion tons of lignite, of which more than 95% can be exploited by open cast method. The paper deals with the existing geological and mining conditions of the zone , the distribution by mining basins and exploitation perimeters, the open cast working technologies and the economic outcomes obtained throughout the time. Years ago, for the improvement of the economic situation as a whole and in each unit, a large production reorganization, technology update and modernization process was started up. There are described the rehabilitation measures of the technological lines and modernization of the equipments of the production flow-sheet, measures developed at present, too and which will still continue in future. There are mentioned the equipments considered, the components under modernization and the economic outcomes obtained so far. At the end of the paper there are presented the future actions for the equipment modernization and perspectives of the lignite deposit exploitation to meet the national economy requirements of solid fuels.

Aug 1, 2013

By George Wilkinson

"AbstractThe consistent relationship between the availability of electrical energy and our economic wellbeing is well known. As we develop the energy we need to nurture industrial civilization in decades ahead, we will at the same time reduce our reliance on dwindling supplies of oil and gas. Coal and uranium will be developed as our major fuel sources to meet medium-term. energy needs, followed by fusion and solar energy for the long term.IntroductionTHIS PAPER treats the matter of energy in a way that is quite different from that of the crisis-type atmosphere which surrounds so much of it currently in the news media. On the one hand, we lift the whole subject of energy out from its present-day involvement with short-term issues and take an important longer-term look at the solutions which lie before us. On the other hand, we recognize that short-term issues are important and, as we are reading and hearing, many of the right short-term solutions continue to elude our politicians, our policy makers, and even some of those with knowledge and authority in the energy field.A year ago, if you asked people how they would go about conserving energy, they would probably have said turn out the lights. They would probably say the same thing today, but they might also include other things such as driving the automobile more slowly or putting more insulation in the attic. However, their first impulse is still to use less electricity."

Jan 1, 1977

By Suzanne Paradis

Geographic distribution ? Deposit economics ? Temporal distribution ? Tectonic settings ? Basin architecture ? Morphology ? Ore-fluid chemistries Key exploration criteria

May 1, 2006

By M. O. Makwarela, M. W. Erwee, K. Bisaka

"Energy efficiency in mining and minerals processing forms part of Mintek’s long-term research strategy which includes a specific programme designed at overcoming the challenges faced by the South African pyrometallurgy industry.The electric smelting industry is currently severely constrained by the global economic downturn as well as by the availability and increasing cost of electricity. Efficient utilisation of electricity through energy recovery systems and improved smelting process flowsheets can significantly contribute towards creating sustainable operations.Apart from efficient engineering design and solid process control, smelting of either cold or hot pre-reduced ores has been shown to decrease furnace electricity consumption by more than 40%. Various methods of solid-state reduction tests have been carried out at Mintek in order to select the most appropriate process option in the context of the South African industry. This paper summarises a subset of the results obtained, specifically on pre-reduction tests done on South African chromite and manganese ore pellets.In this set of tests, it was found that the use of an organic binder, together with B2O3 as flux, promotes manganese ore pre-reduction, but retards the pre-reduction of chromite. By pre-reducing the manganese ore feed, significant cost savings can be achieved in subsequent smelting processes and there is potential to minimise manganese losses as a result of fuming, due to possible lower operating temperatures."

Jan 1, 2016

By D. A. Jacobson

Mining operations, whether new or existing, are constantly looking for ways to maximize production and improve energy efficiency, while keeping the footprint required to a minimum. The Nordberg MP1250 cone crusher was designed with these three goals in mind. A series of side-by-side evaluations comparing an MP1250 to an MP1000 were completed at two Freeport-McMoRan operations. The first evaluation began October 2009 in a tertiary position and the second began March 2010 in a secondary position, where it remains in full production today. Utilizing 25% higher power capacity than the existing MP1000 tertiary crushers, the MP1250 had 29% higher capacity and 17% lower specific energy, adjusted for differences in feed and product size. The MP1250 compared to the existing MP1000 secondary crushers achieved 30% higher capacity at a slightly reduced specific energy, while achieving a finer product. The MP1250?s higher capacity and energy efficiency may have application in many crushing plants. Depending on site specific economic factors, greenfield projects may benefit from a smaller footprint and less ancillary equipment, whereas brownfield projects may benefit from higher capacity or a finer product within the same footprint.

Jan 1, 2012

By Charlie Harper

Open Pit Mining of Golden Band Resources? EP Gold Deposit Golden Band Resources Inc. (GBN:TSX-V) is Saskatchewan&apos;s newest Gold Producer. Located in the La Ronge Gold Belt of northern Saskatchewan, GBN has over 875 km2 of claims with 12 known gold deposits and 4 former producing mines. Production has begun at the Roy Lloyd Mine (Bingo Deposit), to be followed initially by our EP and Komis properties. Development of the underground infrastructure at the Roy Lloyd Mineis continuing and on schedule. Production from these deposits will feed our centrally located and 100% owned Jolu mill. We have our provincial environmental permits in place, and we have an established infrastructure including a 400 tonne-per-day mill, year-round road access, and access to grid power. Construction of the grid power line and the above ground tailings facility are now complete.

Nov 1, 2011

By J. R. Donald, K. Scholey

"Nickel has been mined and processed from the Sudbury basin for over 100 years. During this period, the process has evolved into what is one of the largest and most complex mining and metallurgical facilities in the world. This paper will describe the geology and mining of the Sudbury basin as well as the Copper Cliff metallurgical flowsheet circa 2005, including:•,Clarabelle Mill,•,The flash smelting furnaces,•,The bulk converters,•,Matte casting, separation, and processing•,The carbonyl refineries•,Carbonyl residue processing•,Copper processing•,Sulphur productsThe challenges of today and the opportunities for the future are discussed."

Jan 1, 2005

By Gerald Blackmore

This paper discusses the present state and future trends within the coal industry, and then goes into the reasoning behind these planned trends. Such factors as marketing, costs, new mining techniques and machinery, and manpower and human resources are considered. Finally, the author refers to the effect that these trends will have on the coal industry of Cape Breton.

Jan 1, 1968

By Karl J. C. Harries

This paper looks briefly at some of the agreements and types of royalties that may be met during exploration activities, but does not go into details relating to them. Agreements can either make or break a deal or relationship. A well drafted, comprehensive and fair agreement can create good relations and trust among the parties and will go a long way towards making a deal work. In the best of all worlds the agreement will be put away and not need to be referred to after it has been signed (but it will be there if needed to sort out potential problems). On the other hand, a poorly drafted agreement or one that is inappropriate to the circumstances or unfair to one of the parties can break a deal and end up with the parties facing each other in that expensive, unproductive and time-consuming occupation ? a lawsuit. Accordingly, it is advisable to involve professional advisers with any agreement. The straightforward one may involve no more that a read through whereas the more complex agreement will require considerable involvement. There is, however, one rule for every explorationist to remember: a professional adviser is only an adviser. His responsibility is to make sure that you have the necessary information to make a reasoned decision but the decision is yours, not the adviser?s. It is your deal, you are going to have to live with it, and it is inappropriate for an adviser to introduce new concepts or amend negotiated ones without your specific instructions. Mineral exploration agreements, although basically option, acquisition and joint participation agreements, come in all the shapes and forms, appropriate to give effect to the endless variety of deals negotiated by the ever-active minds of explorationists. You will note the reference to "joint participation agreements" rather than "joint venture agreements". The latter term was purposely avoided because, with the current activity of explorationists from common law jurisdictions in civil law jurisdictions, it has become necessary for the explorationist to become familiar with corporations and shareholders agreements. As most of you are no doubt aware, under the civil law system a joint venture is normally not recognized as a legal entity and, therefore, joint participation in projects is usually by way of corporations.

May 1, 2003