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Tapira Mine (Tapira, MG, Brazil) is the largest phosphate ore and concentrate producer in Brazil. The mine is an open pit, which until recently operated with a large equipment fleet and now uses a smaller fleet operated by contractors. The annual production reaches 17 Mt of ore plus 14 Mt of waste at a stripping ratio of 0.82. Defining the geological boundaries and forecasting the annual production can be a difficult task if not performed on a reliable model. The geological model has been totally reviewed as well as the estimation process. Ordinary Kriging has been used to build the new block model with P2O5 and contaminant grades. After estimation, block model validation and classification criteria definition to assess resources and reserves, the result is given by the life-of-mine plan is defined after pit optimisation and design. The Lerchs-Grossmann algorithm implemented in the NPV Scheduler was used to define the long-term production targets based on the main parameters P2O5 and the contaminants that are just important to the beneficiation process.

May 1, 2010

By Jack T. Work

Spiraling costs in every segment of the open-pit mining cycle is a fact of life that every operator must reckon with. The introduction of various shock absorbing devices for rotary drilling is one recent innovation that may significantly reduce overall drilling cost, increase drill availability, and lower maintenance requirements. In a recent all-inclusive test in taconite ores, shock absorbers on Bucyrus-Erie BE 60R and Gardner¬Denver GD 120 rotary drills were directly responsible for overall savings of up to $41.06 per hour. What is It? A shock absorber is simply a device installed between the rotary drive head and drill steel that cushions the two. It functions in the same manner as springs and shocks on an automobile. Some benefits associated with use of the tool are readily apparent on a daily basis; other benefits are realized over longer time intervals and through continued use. A properly designed shock absorber will: •protect the drill from severe vi¬brations, improve rock bit performance, allow application of the best weight-on-bit and rotating speed under all drilling conditions, •function effectively over a wide range of applied bit weights, • have a spring rate soft enough to perform its primary function of absorbing both rotary and vertical vibrational forces generated by rough drilling, •be reliable and subject to as little maintenance as possible, •be easy to install and remove, and • be of such an economic benefit so as to offset the added expense of its application. A shock absorbing tool developed by BJ-Hughes Inc. was used in a recent test. The "Smoothdrill" is just one of the products currently available. This unit absorbs both rotary and vertical shock loads and has no mechanical parts so lubrication is unnecessary. A rebuild of the unit consists of removing the worn rubber element and inserting a new element, an operation taking less than one hour. Minimizing Vibrations Severe vibrations on a blasthole drill operating in broken and discontinuous formations have visible effects. These vibrations often cause structural damage when allowed to' continue, resulting in fatigue cracks in the mast and related structural components in the drill. When rough running formations are encountered, drilling must be interrupted and possibly shut down. Usually, the drill operator resumes drilling using less down pressures and various rotational speeds until firmer drilling is encountered. An effective shock absorber can substantially reduce these vibrational forces so more down pressure can be applied in bad ground. It is generally accepted that longitudinal vibrations and cyclic forces are more effectively reduced if a tool is designed to incorporate a relatively "soft" shock absorber. The softness of any shock absorbing tool is best judged by its spring rate-the weight required to produce a given amount of deflection, commonly expressed in units of kg per mm or pounds per inch of deflection. All shock tools use a resilient member such as rubber springs, steel springs, fluid, or gas springs to absorb

Jan 4, 1980

By Donald Leroux, Jean-François Wilhelmy, Ahmed Bouajila

"A young private R & D organization, COREM celebrated its 10th anniversary in 2009. Managed by a consortium of nine mining and metallurgical companies, COREM has the mandate of increasing the competitiveness of its member companies through the development and transfer of mineral processing innovations. Typical technologies developed by COREM include alternative mineral processing techniques, novel operating strategies, innovative sensors and process simulation software. Many of them were developed in partnership with universities and selected research organizations.Because the COREM membership base is broad (from ferrous to base, to precious metal industries), its R & D program must deliver technologies with applications within a wide spectrum of mineral processes. Comminution, physical (gravity and magnetic) separation, flotation, cyanidation, pelletizing and thermal processes are the main topics of the R & D program. A number of new technologies have been developed and transferred to the plants of member companies. These examples of transferable technologies demonstrate the capability of COREM to impact the bottom-line of its member companies.INTRODUCTIONCOREM is a private mineral-processing R & D organization that operates from its own laboratories and pilot-plant with its own staff of professionals and technicians (about 95 persons). It is managed and financially supported by a consortium of nine mining and metallurgical companies and three provincial and federal ministries. The very ‘down-to-earth’ mission statement of COREM is to increase the competitiveness of the mineral processing plants of its members. The eighteen plants upon which the COREM technology development program is currently based can be found in Québec, Newfoundland and Labrador, New Brunswick, the Netherlands and Botswana."

Jan 1, 2010

By P. Schmieder

"The close vicinity of mining companies to other sites that are used for commercial and residential purposes or to areas under conservation as well as the fact that the people become more and more sensitive to emissions have led to a negative attitude towards mining operations in the neighborhood. It is above all the use of drilling and blasting techniques that give rise to objections, in the course of which demands for more environmentally-friendly production methods have been voiced. It is in this context that production methods without the use of explosives are considered as an option. After all, the use of such production methods is the only alternative for some quarry operators. The question is what are the true benefits of these techniques and what is the relation between a possible improvement of the environmental effects on the one hand and the technological potential as well as the costs on the other. It is intended to assess the mining techniques for solid rock in their entirety. This paper will therefore look at the aspects for assessing mining techniques in the context of their environmental impact and the costs."

Jan 1, 2005

Impala Platinum?s No.16 Shaft mine is currently under construction and is expected to reach full production of 256 500 tons per month by 2014. Mining will start at 1 260 m below surface with a maximum mining depth of 1 535 m where virgin rock temperatures of 56.6°C will be experienced. As a result of depth, high virgin rock temperature and narrow reef mining, an expected total of 31.5 MW[R] of air cooling capacity will be required to achieve acceptable underground conditions. This will be achieved by cooling mine intake air in a single dedicated air cooling installation located on surface. The compact installation includes air cooling spray chamber, refrigeration machines, condenser cooling towers, evaporator and condenser water reticulation as well as all electrical and control systems. Construction and commissioning of the first phase of this air cooling installation has recently been completed on a turn-key contract basis.

Jan 1, 2009

By Norman O. Lotter, Virginia Lawson, Mika Muinonen, Dominic Fragomeni, Jorge F. Oliveira

Development of metallurgical flowsheets from drill core to production of finished metal involves two main domains: process mineralogy to sample the ore and develop a successful flowsheet producing saleable concentrate; and extractive metallurgy to convert that saleable concentrate to finished metal. Effective flowsheet development for a new or brown-field concentrator and processing facility is essential to project schedule and return on investment. Over the last decade in particular, the integration of geology, mineralogy, sampling, and mineral processing have empowered the development of an improved practice in flowsheet development. The use of geometallurgical units as a basis for best-practice sampling delivers representative study material to the laboratory. Modern automated mineralogy characterises the whole rock assembly and paymetal mineral hosting, to address downstream process implications. Batch scale flotation testing then uses this information to design and perform well-focused strategies. At early stages of the project, the Extractive Metallurgy team is engaged to determine processing constraints or other economic drivers in conversion of the saleable concentrate into finished metal. The team evaluates available technologies, assesses the impurities and key properties of the given concentrate. In many cases, changes to mineral processing flowsheet are required to maximize value per tonne of concentrate. Site conditions, availability of infrastructure, energy and power all play an important role. Modern metallurgical simulation tools such as FactSage™ and METSIM™ can quickly define the appropriate test program for each process. Bench scale testing and appropriate scale of piloting can confirm simulations and provide design criteria. A case study demonstrates how effective use of these tools and a multidisciplinary team can accelerate flowsheet development, while reducing costs and ensuring that the designed processing facilities maximize project value with minimum risk.

Jan 1, 2014

By V N. Rudashevsky, F Melcher, J Lodziak, D Klosa, N S. Rudashevsky, M Sitnikova, L Gast

A combination of novel and æclassicÆ methods, namely electric pulse disaggregation (EPD), hydroseparation (HS), preparation of monolayer polished sections, and mineral liberation analysis (MLA) was employed to study ores from platinum pipes (Bushveld Complex, South Africa), pristine PGE mineralisation of the Main Sulfide Zone (Great Dyke, Zimbabwe), as well as ancient and modern gold/PGM placer deposits. It is shown here that the EPD technique liberates mineral grains of interest without any visible destruction allowing the study and analysis of individual rock-forming and ore minerals, in our case especially platinum-group minerals. The HS method is an effective tool in concentrating heavy minerals by factors up to 10 000 fold. As near-total recovery of grains >10 ¦m is achieved, the nugget effect can be overcome also in case of limited availability of samples (drill core, museum specimens). The MLA technique is a fast tool to detect and characterise mineral phases in ores and ore processing products. Many mineralogical parameters of individual grains and mineral assemblages can be deducted and documented. The results show that the techniques employed, either on their own or in combination, provide a wide range of additional information especially on platinum ores which is beneficial to both the researcher and the metallurgist.

Jan 1, 2008

By Haiping Sun, Samir Ganguly, Oleg Ostrovski, M. Yaser Lone

Wettability of graphite by synthetic SiO2-Al2O3-CaO-MnO slags with varied MnO content and by industrial slags was studied at 1350-1600 °C using sessile drop method under argon atmosphere. Initial contact angle was the lowest (110-115o) for the MnO-free slag. For slags with 10-40 wt% MnO, the initial contact angle was in the range 125-135o. The contact angle decreased with the contact time. The change in the contact angle with slag mass was found insignificant. The surface tension of slags obtained from the drop shape analyses was 500-800 mN/m and varied in a narrow range with temperature and MnO concentration. The reduction rate increased with increasing MnO content in the synthetic slag from 20 wt% to 40wt% and temperature. Increasing temperature also increased the rate of reduction. No correlation was observed between the reduction rate and MnO content in the synthetic slags in the range 0-20 wt% and in the industrial slags. The rate of SiO2 reduction from the molten slag was close to the rate of MnO reduction. The MnO-free slag had the largest contact area with graphite substrate. Keywords: reduction, wettability, graphite, slag, manganese, surface tension.

Jan 1, 2007

By Keila Gonçalves, Aline Tavares, Danielly Couto

"The sulphide copper deposits from the Carajás area (North region of Brazil) were generated by the percolation of hydrothermal fluids in volcanic and granitic rock and are denominated as IOCG deposits (iron oxide copper-gold deposits). During these hydrothermal events a wide variety of gangue minerals such as amphiboles, biotite and fluorite were formed. These gangue minerals are enriched in fluorine and chlorine which are deleterious elements in the copper concentrate. Chalcopyrite and bornite are the main copper-bearing minerals and they can occur in veins, in brecchia or disseminated in gangue.The study, which included bench scale flotation tests and minipilot plant tests was aimed at improving the fluorine rejection in the flotation process during the flowsheet design for one of these Carajás sulphide copper deposit. All of the study was supported by quantitative mineralogical techniques such as QEMSCAN and the use of a scanning electron microscope (SEM).This paper describes and discusses the results obtained in the metallurgical tests and emphasizes the importance of the quantitative mineralogical characterization during the process conditions optimization and flowsheet design.INTRODUCTIONIron oxide copper-gold (IOCG) deposits encompass a wide spectrum of sulphide-deficient low-Ti magnetite and/or hematite ore bodies of hydrothermal origin and normally have important copper sulphide reserves. In the Carajás mineral province, located at the southeast part of the Amazon Craton in Pará State (Brazil), there is a variety of world-class (>200 million tonnes) Fe-oxide Cu-Au deposits (e.g. Salobo, Cristalino and Sossego), whose genesis has been assigned to hydrothermal fluid percolation in volcanic and granitic rocks. Figure 1 displays the location of the Carajás area.The hydrothermal thermal fluid composition was extremely variable. It may have contained gases, salts (brine) and metals. The metals were carried as various complexes and it is thought to have involved sulphur, chlorine and fluorine containing species. This resulted in some minerals formed during the hydrothermal alteration having high fluorine and chlorine contents. These elements result in smelter penalties in a copper concentrate because they cause the smelter off-gases to be more corrosive."

Jan 1, 2011

By A. Fuerst

The recent seismic events have shown that earthquakes have an immense destructive power. Chile was hit in February 2010 with a seismic intensity of 8.8 on the Richter scale, and had loss of about 700 killed persons, while Haiti was hit in January 2010 with 7.0 killing about 220?000 people. The event in Haiti showed that the seismic events can lead to a disaster if no preventive measures are taken. On the other side, the seismic event in Chile has hit a well-prepared country with moderate consequences. The earthquake with 6.6 Richter in Japan in March 2011, have further shown how severe the consequences can be if critical equipment is involved. Fortunately, the equipment in a mine has not the potential hazard as a nuclear power plant. Anyway, we are diligent and it is obvious that the seismic risk may lead to a real disaster even if the probability is small. The GMD is an important component in the grinding circuit of a mine. This paper maps out earthquake-prone areas including expected earthquake magnitude calculated according to relevant standards, focusing mainly on the building code IBC 2009. An overview is provided on how this standard is applied to mining equipment to minimize damage and aid large mills in operation to successfully withstand seismic effects. The differences in stresses and forces on the GMD and foundation are shown based on a turning and stopped mill simulation during an earthquake. The results demonstrate the need to maintain active and operating earthquake detection systems. Aside from detecting an earthquake?s magnitude, the sensor information can also be used to reduce the harmful effects that an earthquake has on mining equipment. As follows the earthquake requirements are defined. The last part of this paper explains how to fullfill these requirements.

Jan 1, 2012

By A. W. Ambrose

The output or oil and gas rrom the producing fields in the United States is rapidly deelining. Coincident with this decline is a steadily increasing demand ror petroleum and its products, but at present there are no commercial substitutes ror gasoline and lubricating oil. Undoubtedly, many new fields will be discovered in this country during the next rew years. Indeed, there may be periods or temporary flush production that ror a rew months or a year or perhaps two years will afford a surplus. Such peaks are temporary and should not be given too much weight in considering the relation between petroleum supply and our national lire. In considering this problem we must regard a long period or time, and, ir we do that we shall see that domestic production will be unable to keep pace with consumption. Hence, the public good demands t~at the highest efficiency obtainable be practiced in the production or oil. To accomplish this end, the operator or to-day should so organize his rorces ror development and production that he recovers every barrel or oil that can be recovered at a profit. This necessarily involves the use or eeonomical and scientific methods or development a:nd production and the elimination or waste. The Bureau or Mines has ror years urged the conservation or petroleum and its products, and has pointed out that -such conservation should start before the oil is brought to the surface rather than arter it is in storage tanks. Losses or petroleum underground have undoubtedly been rar greater than losses in storage, in transportation, and in refining. The quantity lost usually is indeterminate, and hence difficult to express in terms or money, but by remembering that entire oil fields have been ruined by invadIng waters some idea may be gained or the importance or underground waste. The petroleum engineer is coming to be recognized as an extremely important aid in the intelligent development or oil fields. In this paper an effort is made to outline ror the engineer and producer a field or work whereby science and engineering not only can but have been applied practically. The mining engineer has been the direct- ing hand in the development of mines, and it is being recognized more and more that the petroleum engineer has a similar function in developing oil properties. Thispaper aims to show the general method of procedure in studying underground conditions in producing oil fields and how such study may not only correct but even prevent great unnecessary losses. Such work provides the company with maximum insurance for the field against loss and is accompliphed at minimum cost and minimum risk. Throughout the paper reference is made to oil wells and oil fields, but to a certain degree many of the suggestions relating to oil wells are applicable in the care and protection of gas wells and in solving gas problems.

Jan 1, 1921

Selective Removal of Arsenic from Acid Mine Drainage Containing Ferrous Ion Using Sulfide Precipitation Method

Sep 13, 2010

By G K. N Subasinghe

"In the design and operation of mineral processing plants, knowledge of the variability of ore properties and that of the expected metallurgical performance within the orebody is of great importance in order to avoid both production constraints due to inadequate design and less than expected metallurgical performance during operation. Of the many properties that determine the performance of downstream separation processes, such as flotation, gravity separation and leaching etc the liberation characteristics are of primary importance.Current methods of evaluating liberation characteristics of ores such as the use of Mineral Liberation Analyzer (MLA) and QEMSCAN techniques are expensive and suffer from the drawback that these tests are performed on comminuted particles at a given grind size and/or samples of product streams. This problem could be overcome by developing predictive models of liberation that can predict the grade distribution of comminuted products at any grind size based on texture of the parent rock. This paper discusses a procedure that has been developed to predict liberation using information obtained from a sample of the parent rock such as drill core, based on Barbery’s liberation models. The required characteristic statistical functions have been evaluated from image analysis techniques using scanning electron microscope (SEM) images of the parent rock and narrowly sized comminuted particles. Such information can then be used in a predictive model to predict or explain the variability of metallurgical performance at various grind sizes used in future operating plants. The model will predict not only the valuable mineral liberation but also gangue liberation, which will be useful to those who are looking to remove liberated gangue from comminution circuits.CITATION:Subasinghe, G K N, and Dunne, R, 2016. Predictive Model of Mineral Liberation for Geometallurgical Applications, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 347–350 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By A. N. Fried

With the growing importance of fluid injection in recent years, the petroleum industry has been investigating and field- testing a variety of new methods designed to modify the physical properties of reservoir oil to improve the efficiency of gas and water injection. These procedures include condensing-gas drive, LPG (liquefied petroleum gas) injection, alcohol-slug process, high-pressure-gas displacement, detergent-solution flooding, and in situ combustion (30, 37).3 A new and different method to increase the effectiveness of gas and water injection has been tested by the Bureau of Mines, Consideration of both fundamental and practical factors that operate to limit the oil recovery attain- able by conventional oil-displacement mechanisms led to the concept of a displacement mechanism called the foam-drive method. This report describes the experimental study that tested this concept in the laboratory.

Jan 1, 1961

By J. M. Mutmansky, L. Xu

"IntroductionSince the establishment of the star,just concentration of 2 mg/m3, a strong effort has made by mining engineers and researchers to provide better dust control equipment and procedures for underground coal mines.Particular areas of success have been implementation of better coal-cutting strategy to control dust generation, better design of water sprays for dust suppression and air movement, use of scrubbers, and improved design of face ventilation systems. A drastic improvement occurred over time such that the average dust concentrations for continuous miner operators dropped from 6.5 mg/m3 in 1968 to 1.3 mg/m3 in 1980 and for auger, cutter, longwall, and roof bolter occupations from 2.7 mg/m3 in 1973 to 1.6 mg/m3 in 1980 (Niewiadomski, 1983).While dust concentrations in mining sections have been dropping considerably, one problem area has been mining sections where quartz is a considerable portion of the airborne dust. The federal regulations require that quartz content must be held below 0.1 mg/m3 in the air regardless of the concentration of the total dust. This legislation limits the allowable dust concentration to a ""reduced standard"" of 10/ (% quartz) when the quartz content of respirable dust in the mine atmosphere is more than 5%. Today, approximately one-third of underground coal mining operations have designated areas with more stringent dust standards in place, and many mines experience considerable difficulty in meeting these standards (Jankowski, and Babbitt, 1989).It is well known that metal miners subjected to respirable dusts high in quartz have a higher incidence of silicosis than those exposed to dust low in quartz. However, the role of quartz in the development of coal workers' pneumoconiosis is still a highly controversial question, in spite of the large number of research projects devoted to this subject over the last 20 years. Because coal seams contain less quartz than metal ores and quartz often comes from sources outside the coal seam (e.g., roof and floor), it is difficult to relate studies that deal with the quartz content in coal seams and the incidence of coal workers' pneumoconiosis. Hamilton, Ogden, and Vincent (1983) have provided a plausible explanation for the incidence of the disease by hypothesizing that the quartz content does not affect the probability of developing pneumoconiosis until some threshold value (generally thought to be about 10%) is exceeded.The objective of the research studies summarized here was to obtain a better understanding of quartz occurrences in airborne coal mine dust by studying the variations of the quartz levels in different dust sizes and the relationship between the quartz content in airborne coal mine dust and the quartz content in the mined material. The implications of the results to control of dust in high-quartz sections will also be discussed."

Mar 1, 1992

By James H. Cobbs

The purpose of this study is to investigate the application of boring equipment to the production of anthracite coal from steeply pitching beds. Both raise boring and augering equipment were considered. Previous studies (11) have indicated that boring equipment may have definite applications to the development of steeply pitching anthracite beds. This investigation was to carry forward previous work to determine the possible application of the two different types of equipment being considered. Previous conclusions have been substantiated by the results of this study.

Jan 1, 1975

By W. van der Merwe

With the gold industry looking to process more complex ores, the online measurement and control of cyanide addition to the gold leaching circuit has become more crucial. This paper compares the two commonly employed "free" cyanide online analysis methods (amperometric and potentiometric end-point silver nitrate titration) with the common site laboratory rhodanine endpoint silver nitrate titration and ion selective electrode methods. Measurement differences between these methods are presented and discussed for cyanide solutions containing copper and zinc with varying cyanide to metal ion ratios. The resulting cyanide available to leach gold is also compared with these measurements.

Jan 1, 2011

By Arnold B. Hubbard

Automatic control instruments were utilized by the Bureau of Mines for routine assays of large numbers of oil shale samples and other bituminous materials. The standard Fischer assay method was automated by automatically controlling the heating cycles of a battery of 12 electric heaters with electronic controllers and programmers. The condensers were cooled with a modified automatically controlled refrigeration bath. The complete assembly consisted of 12 retort units, necessary control instruments, and the refrigeration bath. This equipment was capable of producing more consistent results than those previously obtained with the gas-heated retorts and of increasing the output of assays substantially with no increase in operating personnel.

Jan 1, 1965

By L. O. Bacon, H. R. Joesting, J. H. Getz

"INTRODUCTION For a number of years manganiferous iron ore has been mined on a small scale at Boston Hill, in Grant County, N. Mex. Total production up to 1943 is estimated to be over 793,000 long tons, containing 8 to 35 percent manganese and 26 to 46 percent iron. 4/ During 1941 to 1943 production was estimated to be 206,000 long tons, containing about 13 percent manganese and 37 percent iron. During 1944 daily production was several hundred tons, mostly from a single open pit. Several moderately large deposits have been mined: and many smaller ones have been found.From February to April 1945 geophysical surveys were carried out on Boston Hill by the Division of Geophysical Exploration, in cooperation with District 5, Central Region, Bureau of Mines, to determine if hitherto undiscovered manganiferous iron deposits exist. Field work was interrupted for a total of about 1 month during this period by work on other projects in nearby areas. Previous to the geophysical surveys, a preliminary examination was made by H. R. Joesting to determine if geophysical methods could be utilized in exploring the area. 5/Field measurements were made by L. O. Bacon and J. H. Getz, project geo¬physicists of the Bureau of Mines, under the general supervision of H. R. Joesting. A grid survey of the area, to locate geophysical stations, was made by Paul Russell, Bureau of Mines engineer, who also collected specimens for laboratory tests. Most of the computations and the preliminary magnetic and resistivity maps were made by L. 0. Bacon."

Feb 1, 1948

By C. S. Harloff, Frank R. Corwin

THE Nichols Copper Co., associated with the Phelps Dodge Corp. and the Calumet & Arizona Mining Co., has constructed at El Paso, Tex., and is now operating a copper refinery with a yearly capacity of 100,000 tons of anodes. Transportation facilities were perhaps the most important of the considerations that led to the selection of this site. The rapid industrial development of the Middle and Far West has increased the consumption of copper there. The advantage of local refining as against shipping the copper to the Atlantic sea- board is apparent. Copper refined in the Southwest is equally competitive for export shipment, either from the Gulf or the Pacific Coast ports. The tonnage of copper produced in the Southwest not only justifies the construction of this plant, but may warrant considerable expansion in years to come.

Jan 1, 1930