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By T. Schmidt, J. Merza

"This study considers two lead/zinc/silver orebodies which have historically had a problem with pyrite, pyrrhotite and sphalerite contamination in the lead circuit. The problem was previously addressed with high dosages of sodium cyanide as the primary depressant. However, large amounts of cyanide led to environmental problems in the effluent, especially during winter months. The objective was to reduce cyanide consumption while maintaining or improving overall lead grade and recovery via the reduction of the undesirable sulphides.Extensive laboratory and mill testing was necessary to determine the optimal operating parameters for continuous plant application. Evaluation of data received from this testing has shown that selective addition and optimization of the dosage of Unimax SD100 to specific areas of the flotation and grinding circuits has resulted in improved Pb grade and recovery. Parameters such as pH control, regrind operation, the cyanide/Unimax ratio and sulphide mineral content may also affect the performance of the depressant. Each factor is discussed and optimal operating conditions were determined based on the testing.Results are presented for two case studies. Both indicate that Unimax SD100 improves the lead grade/recovery curve by increasing iron and zinc rejection while reducing cyanide consumption and the resulting environmental concerns. 1. Hart"

Jan 1, 1992

By W. H. Forbes

The prevention of accidents from falls of roof and coal requires a considerable amount of personal judgment , for conditions are different even in adjoining working places in the same mine , and conditions may change from hour to hour even in the same working place as the coal is shot down and loaded . Experience has shown that many men can not or do not exercise enough care to protect themselves from injuries ; moreover , where the foremen have been made directly responsible for the safety of the men under them , accidents from falls of roof and coal have , in many instances , been reduced as much as 50 per cent . There is now no question that careful , constant , and intensive supervision is essential in preventing acci- { dents and more especially accidents of this class . Falls of roof and of coal account for approximately 50 per cent of all coal mine accidents and annually result in the death of approximately 1,000 men and cause lost - time injury to approximately 50,000 men . These and other accidents are recurring with little or no diminution , usually not because of the lack of knowledge of safe and dangerous practices , or of the technique of safety , but largely because of the lukewarm interest of major executives in safety or the failure of mine officials to formulate and to enforce common - sense rules and regulations . When failure is the outcome of a sincere attempt of the managing officials to teach safety to the miner , the fault may usually be attributed to misguided effort . Various solutions for the problem of eliminating accidents from falls of roof or coal have been suggested , some of which are : Standard system of timbering for the specified mining districts ; departure from the room-and - pillar system to a more concentrated system of mining ; more intensive supervision - that is , 1 section foreman for every 25 loaders instead of 1 section foreman for 75 , 80 , or even more loaders the practice in most mining districts . - However , investigations conducted by the writer at numerous mines operated by a number of mining companies in several districts show that employees and officials alike are inclined to work under loose and unsupported roof , relying solely on the " drummy " sound and on their judgment and experience as to whether the roof will stay in place for one hour or for several hours . With but few exceptions , men who had been injured by falls of roof or ccal or were found working under loose and unsupported roof , admitted that they knew of the possibly unsafe condition , but it was their opinion that the roof or coal was not loose enough to fall for some time .

May 1, 1931

By W M. Gilchrist

This paper gives an estimation of the future requirements of the western world in relation to energy re-sources. It then goes on to outline the role that atomic power -with its basic raw material, uranium -will play in supplying these energy requirements. Canada's position in this picture is covered, and some interesting forecasts are made. Introduction I T is possible that the following remarks will appear to have more to do with power than uranium. However, to fully comprehend what is in store for the Canadian uranium mining industry, we must be able to estimate the potential requirement, and, to do this satisfactorily, a thorough understanding of the circumstances that will give rise to that demand is necessary. The growing need for electrical energy will play by far the major role, as large tonnages of uranium will be required for its generation. The nuclear weapon has, up to the present, comprised the major market for uranium.

Jan 1, 1964

By John C. Draper

[Duquesne Light Company's three power plants in western Pennsylvania are now receiving high BTU clean coal from a new coal preparation plant. When burning coal from this plant, particulate emissions are greatly reduced and the sulfur content of stack ace descend. The cleaner coal also leads to more effecting overall operating of the power plants because of less bulk handling of fuel and ash. Environmental improvement is an important benefit of the cleaner, more complete combustion.]

Jan 1, 1976

By R. M. Jara

This work evaluates and characterizes the impact of the support size and mining dilution of a block model in the operation and selection of equipment at an open pit mine. An exploratory analysis and geostatistical modelling of the grades assayed on a set of drill hole samples is performed, which allows constructing a grade model on a dense grid by means of a conditional simulation. The grades are then averaged to greater selective mining unit supports in order to proceed with the study and methodology. First, the metal-tonnage curves are used to analyse the loss of selectivity on the in situ resources caused by a change of support. Concerning the ore reserves and their mining sequence, defined in the pit optimization and analysis process, the same curves prove that the loss of selectivity is more accentuated. Second, the importance of the block boundary dilution produced during mining operations is assessed. Its value depends on the amount of ore in contact with waste, on the loading error of the equipment and on the ore loss/waste dilution criterion assumed by the planner. The dilution percentage and the differences between waste and ore grades become higher when the block size decreases. For these reasons, considering the dilution in the production plans makes mining a small support more constraining. An adequate delimitation of the orebody can improve the mining selectivity, leading to greater income. Finally, a study of the increase in mining cost that provides a zero difference in NPV between the different block size options is carried out, in order to determine the maximum increase in mining costs for which it remains profitable to mine at a smaller block size. Keywords: Mining selectivity, support effect, block boundary dilution, selective mining unit size, block model.

Jan 1, 2006

By Johnston W. H

MINING operations in the Waihi mine began, under the present proprietorship in the year 1889. Previous to this, and as far back as the year 1880, the presence of reefs in the Martha Hill had been known, and surface working on a small scale had beencarried out, without any great measure of success. The only method of treatment in use at this time was the old system of light stamps, amalgamating tables and berdans, and recovery by this method being low, little margin for profit was left, so thatthe property in these days was not considered of great importance and work on the area was only carried on spasmodically by different owners.On the transfer of the leases to the present company, calcining, dry crushing, and hot pan amalgamation was adopted as the method of treatment, and this system was continued till the more modern cyanide process was introduced and applied. As themethods of treatment and gold-saving became more efficient with the application of more modern and scientific processes, the importance and future prospects of the mine became more and more pronounced, and mining on a larger and more comprehensive scale was gradually established.As in the case of ore treatment, mining methods in the early stages were not as far adv.anced as the adopted practice of today, and numerous shafts, levels close together in vertical height.

Jan 1, 1912

By A Golsby

Although much talked about, social licence to operate (SLTO) is a relatively new concept that has been deemed as one of the four biggest business risks to a mining project over the life-of-mine. There is no accepted single definition of SLTO and this author understands SLTO to be stakeholder perception of the legitimacy of a project, a company or an industry. At a specific site, and across different sites within the same organisation, SLTO ranges through different levels according to stakeholders’ degrees of acceptance in time and space. Management of SLTO is vital for the mining sector but is difficult as it is informal and intangible. Although there are no key performance indicators, there are certain indicators that enable relative measurement of the ‘level’ of the SLTO. Because of the importance of the SLTO, information management during the entire life-of-mine, from exploration to rehabilitation, becomes crucial for the continued operation of a project. This paper identifies ten basic principles for the management of information to support the SLTO.CITATION:Golsby, A, 2014. Managing information to support a social licence to operate, in Proceedings Life-of-Mine 2014 , pp 389–398 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Sumner M. Anderson

THE ENORMOUS contrast between the mineral economy of Cuba in 1963 and in 1958 was the result of the overall Political changed to which the total economy of the country was intimately lined. Creation of the Cuban Mining Institute (Instituto Cubano de la Minería) to direct all mining activities in the country was an early act of the new Government after the revolution on January 1, 1959. During the next 2 years, the Government confiscated foreign holdings,2 including Unite States investments exceeding $1 billion in value. Foreign mining and metallurgical technicians-predominately from Communist areas-were brought in to reorganize the mineral industries. On January 3, 1961, diplomatic relations between Cuba and the United States were severe and then on May 2, Cuba announced its full-fledged membership in the so-called Communist Bloc. Fifty-four international treaties assured Cuba of Communist economic support, technical and financial assistance, machinery, raw materials, and manufactures. The Soviet Union agreed to buy some Cuban mineral products, and Czechoslovakia stated that it would buy all mineral production offered for the next 20 years, but in both cases at prices said to be much lower than the world market. The mineral productivity segment of the mineral economy during and since the period of political metamorphosis, has withstood the political disruption better than has the economy as a whole, but with no direct measure of the magnitude of its cost. The overall economic record is marked with steady deterioration; the annual average per capita income has dropped from $374 in 1957 to $185 in 1963, when Cuba's deficit with the Soviet Union alone reached an admitted $1 billion.

Jan 1, 1964

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

By G. L. Hohmann

The Waste Isolation Pilot Plant (WIPP) project is authorized by legislation to provide a demonstration of the safe disposal of radio- active wastes generated by the national defense programs and activities of the United States. The U.S. Department of Energy (DOE) is proceeding with the implementation of the WIPP project in accordance with the "Department of Energy National Security and Military Application of Nuclear Energy Authorization Act of 1980" (PL 95-164).

Jan 1, 1982

By L. Lorio, B. Hilscher, P. Nayak, N. Yoon

"Mining has been a staple to technological advancement ever since the dawn of time. By harnessing the different physical and chemical properties that each mining commodity brings to the table, more and more innovation is developed and manufactured. As these non-renewable resources continue to be extracted, the industry as a whole faces a challenge in finding the next economical deposit as well as declining grade at the current operations. By means of pre-concentration, ore sorting aims to separate the barren material from the valuable ore to reduce energy consumption and tailings generation, while increasing the feed grade, concentrate grade, mill recovery, and revenue. In addition, ore sorting allows the modification of deposit geometallurgy in order to allow the creation of an optimal mill feed. This paper evaluates the applicability and challenges of ore sorting by utilizing the results from four different mines, and reviews them in detail. The mines include one underground and three open pit mines that are precious metal operations. In order to understand the applicability of ore sorting in these operations, initial rock-by-rock test results and different types of assays (atomic adsorption [AA], inductively coupled plasma [ICP], and fire assay) are utilized. Using the assay results, the grade recovery curves for ore sorting are generated and they are further improved by using and developing an ore sorting algorithm, which is discussed in this paper. The application and evaluation of ore sorting in greenfield and brownfield properties will also be discussed. The state of the art ore sorting technologies for both rock-by-rock and bulk sorting are also reviewed in this paper. The future technologies on the horizon, including different combinations of sensors, are explained. The sorting technologies include X-ray transmission (XRT), X-ray fluorescence (XRF), colour, infrared, electromagnetic, and laser induced breakdown spectroscopy (LIBS)."

Jan 1, 2017

By C. J. Toberman

Improvements in fine (28x0) and ultrafine (200x0) coal cleaning is an acknowledged goal with potential benefits in both steam and metallurgical coal markets. This work focuses on adaptation to fine coal flotation of FLOTE, a computer simulation model of the froth flotation process originally developed in the hard minerals field. FLOTE describes the flotation of solids based on particle surface activity, composition, and size. The quasi steady state model was applied to predict flotation performance at an Eastern Kentucky, full scale metallurgical coal preparation plant. Parameter estimation and model testing used detailed flotation test data from a five stage rougher flotation bank. Overall grade/recovery predictions compared well with known plant performance under variation of principally feed grade, plant throughput and reagent addition; however, grade/ recovery predictions for each cell weaken under overloading conditions. Analysis of grade/recovery over a range of sizes is presented. Suggested model improvements and extensions are discussed.

Jan 1, 1984

By S. Bellec, A. Berton

"Usually, steady state mass balances are used for the design of mineral processing plants. However, this tool does not take into account the impact of process inputs variability nor does it evaluate process transient behaviours between stationary states, such as mill start-up and shutdown. The use of advanced simulations enables the integration of dynamic behaviours in process design decision-making by highlighting situations that are undetectable by using only steady state mass balances. Applying these simulation tools to brown field projects allows the simulator performances to be calibrated and validated on actual plant data before it is used as a prediction tool for the modified plant.Three (3) simulators were implemented at the design stage of a major upgrade project for an ore processing plant in order to assess process behaviours under different production scenarios. These simulators were built to evaluate the impacts on major elements such as mine production, ore stockpile, concentrator production as well as water demand. A validation of individual equipment models was performed whenever sufficient measured data was available. The simulators were then used to study the impact of ore variability (grade, hardness, throughput), to assess day-to-day production special events, and to evaluate the true stockpiles live capacity.The use of a stochastic simulator for equipment sizing allowed a more precise sizing of many pieces of equipment and avoided important expenses in the fresh water pumping system. The dynamic simulator also confirmed that the water in place system would suffice, even in the most demanding production scenario. Finally, the stockpile simulator allowed an important production bottleneck to be quantified and then made possible the assessment of various practical solutions for the stockpiling-reclaiming issues.Post start-up, process data underlines the fact that using advanced simulation tools was useful to mitigate process-related risks associated to the plant expansion, showing generally accurate prediction and adequate equipment sizing, leading to smooth process commissioning. The presented methods are part of what is now routine in Soutex’s participation in both greenfield and brownfield projects."

Jan 1, 2015

The Beginnings of Mineral Processing Research in Canada - A Short Account

Sep 13, 2010

By A. Torkian

Copper mining operations have increased in Iran in the past decades due to price increases and potential for creating jobs in developing countries. Iran consists of many copper mines. The mining operations have a positive economic impact on the region, but may also be the cause of adverse environmental effects. Environmental aspects and the health impact of respirable particulates on the communities and agricultural production in the immediate vicinities have been under scrutiny by the regulatory agencies to ensure sustainable development. The impact of an open-pit mine on the air quality and extent of particulate pollutant dispersion in different directions and times is the focus of this paper. The results of the modeling have been validated through ambient air monitoring. Monitoring stations were installed in different areas within the mine unit operations and around it including background areas where PM10 values were 7 µg/m3. Outside the Complex, particulate concentrations were monitored in 9 different stations and up to 25 km distance. Modeling of point, area, and volume sources was conducted using a 9- year meteorological database. The results showed that particulate quantity decreases rapidly below local standard value of 150 µg/m3 at 2.5 km around the mine and the main pollution is due to the crusher and tailings dump areas. Model outputs were compared to the actual values measured by the air quality monitoring network including villages and crop fields. High overall correlation of about 76% was obtained for most of the locations but lower values were reported for more complex terrain in the region. Remedial actions recommended included road water spraying and better management practices to avoid overloading trucks.

Aug 1, 2013

By E. Ferguson

In evaluating refractory designs for cast house applications, thermal calculations are frequently performed to determine cold face shell temperatures, temperature profiles and metal freeze plane locations within the refractory layer, and heat loss in the steady state condition. A problem arises when looking at molten metal transport crucible designs in that these structures are usually operating under non-steady state conditions throughout their production cycle. Because the molten metal temperature varies with time, and material properties such as thermal conductivity are temperature dependant, mathematical solutions are at best... complicated. This paper presents a relatively simple, iterative solution, that can be set up on a standard computer spreadsheet program, to calculate heat transfer in non-steady state conditions. These calculations can provide curves for (1) molten metal temperature vs time and (2) cumulative heat loss vs time, given variable starting conditions, to aid in the evaluation of molten metal transfer crucible refractory designs.

Jan 1, 2004

By Zhi-gang Que, Sheng-li Wu, Guo-liang Zhang, Bo Su, Chao-gang Hou

NOx released during fuel combustion is one of the major air pollutants, such as acid rain and photochemical smog. At present, still not have an economical and effective method of inhibiting NOx emission for sintering flue gas. Therefore, controlling conditions of fuel combustions to enhance the reduction of NOx is important for decreased the emission. In this study, microsintering furnace has been performed to investigate the effects of NOx emission from char-N during coke breeze combustion. The results show that the emission concentration of NOx decreased with increasing temperature when it is sinter bed temperature higher than 1000℃. The lower emission concentration of NOx was obtained when the concentration of oxygen was decreased. And the maximum concentration of NOx will be reduced with the enhanced of heating rate. If heating preservation time was prolonged, it would promote to NOx reduction with reduction substances resulted in lower NOx emissions in the combustion of coke breezes.

Jan 1, 2015

Validation and Simulation of Optimised Compressive Crushing Ores and aggregates are used in countless applications all around in the society. The frequent and escalating usage of these natural resources requires efforts aimed at not only making do with what is available, but also undertaking actions to improve the production yield and the processes involved. This strive to improve the performance and efficiency of existing crushers and crushing processes has brought about research concerning optimisation of crushing plants as well as theoretical optimisation of crushing. Previous work shows that different applications and different materials require different compressive crushing in order to accomplish a theoretically optimal size distribution. These optimisation results, obtained by genetic evolutionary algorithms and evaluated with so called fitness functions, convey the theoretically optimal number of compressions and their corresponding compression ratios. Presented in this paper are thus some laboratory crushing tests, which are conducted in order to validate a set of previously optimised crushing sequences. More specifically, interparticle crushing sequences are carried out in a Piston-die testing equipment, where samples are sieved between each compression. The subsequent analysis of these results shows good correlation with model predictions, which combined with a comparative study between presented optimisation results and measured data from a real crusher indicate a significant potential for improvement. However, before redesigning crushers according to what is theoretically optimal, the resulting impact as well as the effects on the outcome of a crushing plant must be examined. Crushing plant simulations using the software PlantDesigner« are consequently performed. Models of existing crushers are altered, resulting in changed particle size distributions from some of the crushers in a crushing plant. Thence, it is concluded that significant gains can be made in terms of capacity, process yield and energy consumption.

Sep 13, 2010

By H Thanasekaran, L Christodoulou, J Kohmuench

"Column flotation has been successfully applied to iron ore concentration since the 1980s with the goal of reducing silica content and allowing for the efficient production of pellet feed. Since then, columns have been widely used in iron ore processing due to: their lower capital and operational costs when compared to conventional cells their ability to generate higher concentrate grades and recoveries.Currently, more than 100 columns have been installed within Brazilian iron ore processing circuits for rougher, cleaner and scavenger duties. Despite it being a well-established approach, several technological advances have improved column design, accessories and performance. This work presents the performance of some iron ore columns in Brazil and the recent technological developments.CITATION:Thanasekaran, H, Kohmuench, J and Christodoulou, L, 2013. Column flotation of iron ore - status and advances, in Proceedings Iron Ore 2013, pp 479-484 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Patrick Pelletier Jr., Pierre-Alexandre Bossé, Gianni Bartolacci, Ian Orford, Steve Parent

"Over the last decades, many authors have shown the importance of froth in the flotation process. Mineral recovery is related to froth recovery and flotation. Selectivity is affected by froth characteristics, especially structure and loading. The characteristics of froth textures could therefore be used for diagnosing flotation.Machine imaging, especially image texture analysis, allows on-line measurement of important froth characteristics and process state classification. The measured characteristics include froth texture, loading and stability indicators. To extract information from images, texture analysis tools are used as well as a block-matching algorithm (BMA). For process state classification, images are analyzed with the same tools and clustering is done with multivariate data analysis algorithms.Two case studies, Brunswick Mine Concentrator Cu/Pb circuit and LaRonde Mine Zn circuit, are presented to show that these indicators may be used for diagnosis and control. The influence of manipulated variables on measured froth features is shown as well as the relationship between froth characteristics, mineral recovery and flotation selectivity.INTRODUCTIONImaging is a way to depict abstract characteristics of a scene or an object; it is often related to other types of scientific observations, chemical component concentrations, for example (Geladi and Grahn, 1996). In this paper, the scene is flotation froth. Imaging can be especially useful in applications where it is difficult to obtain the measurements needed for process analysis – froth flotation, for example."

Jan 1, 2006