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By T. Holmes, D. C. Russell, G. Jolly

"The AMEC Oakville office is involved in the design and construction of an iron ore concentrator located in Liberia. Currently, the site ships Direct Shipped Ore (DSO) to overseas customers. The DSO mine-site and port can experience heavy annual rainfalls. The IMSBC Code requires that cargoes are only accepted for loading when the moisture content of the cargo is less than its Transportable Moisture Limit (TML). The moisture content of the DSO has, on occasions, risen to near or above its TML. AMEC was asked to advise whether the concentrate produced from the new concentrator would or would not have the same problems with moisture content and ship loading as the DSO.INTRODUCTION Liberia was, at one time, the world’s sixth largest exporter of iron ore and used some of the most modern mining operations of their time. However, the country has not produced iron ore over the past seventeen years because of civil unrest. The return of stability to the country has allowed the redevelopment of the iron ore industry. ArcelorMittal Liberia (AML) obtained a concession for mining in the Nimba County area of Liberia (Figure 1) in December, 2004 and has studied the known iron ore deposits and former mining operations in this area. It began phase 1 operations in June 2011 with the direct shipping of high grade ore at a rate of up to 4Mtpa. The processing of the lower grade ore in phase 2 of the project requires additional processing capability to produce at the design rate of 15Mtpa. DSO and Concentrate The DSO in the first phase is selectively mined at an average grade of 60% Fe, and then crushed and screened to -10 mm with no washing or concentration. Testing of samples has indicated a size distribution that is finer than typical sinter feed material, although critical material below 0.10 mm is low in most cases, and overall the ore is coarser than typical concentrates or ultrafine products (Feasibility study report, 2011). The phase 1 DSO facility will cease operation after the phase 2 concentrator comes into operation."

Jan 1, 2014

By Braam Blom

PK2 Ventilation shaft is part of Paardekraal No 2 twin shaft system that is being developed to replace depleting Merensky reef production at Paardekraal shaft complex. The sinking team at this shaft faced considerable challenge of improving the total sinking cycle in order to be able to deliver the fully equipped shaft on time and on schedule. The cladding support cycle was identified as the tedious and time consuming activity in the overall shaft sinking operation. Reduction in the time required for handling and setting up the support installation equipment, and the time required for subsequent installation of the necessary support has a direct impact on the overall cycle time, and consequently the overall productivity and efficiency of the sinking operation. This reduction in support cycle was achieved by making use of machine carousel. The objective of this paper is to describe the support methodology that was used during the ventilation shaft sinking and the use of the machine carousel to reduce the cladding support cycle. The machine carousel replaces the traditional use of machine kibble in conventional vertical shaft sinking and has been designed specifically for installation of sidewall support at the shaft bottom during the sinking process.

Jan 1, 2009

By Antti Porvali, Vivek Agarwal, Mari Lundström

Hydrometallurgical recovery of rare earth elements (REE) from NiMH battery waste can be performed using sulfuric acid leaching followed by selective precipitation as double salt (REENa(SO4)2·H2O) by adding Na2SO4 as a precipitating agent. The formed double salts can then be further converted with NaOH solution to form REE hydroxides. However, present literature has paid little attention to how to minimize the consumption of reagents in this recovery process. In the current study, a process model was built using HSC Sim software, and metamodeling of the simulated flowsheet was conducted with the design of experiments (DOE), after which the basic functionality of the flowsheet was verified by experimental work, starting from sulfuric acid leaching of spent batteries. As the process is based on chemical circulation internally in the process, the objective was to investigate the accumulation of the elements in solution, specifically Na+ , K+ , SO4 2− ions and impurities liberated in the NaOH conversion step. It was found out that metamodeling could be utilized in obtaining first estimate of the process behavior, prior to any experiments. Flowsheet functionality with circulated solution was confirmed, obtaining at best 96.9% La recovery.

By Antti Porvali, Vivek Agarwal, Mari Lundström

Hydrometallurgical recovery of rare earth elements (REE) from NiMH battery waste can be performed using sulfuric acid leaching followed by selective precipitation as double salt (REENa(SO4)2·H2O) by adding Na2SO4 as a precipitating agent. The formed double salts can then be further converted with NaOH solution to form REE hydroxides. However, present literature has paid little attention to how to minimize the consumption of reagents in this recovery process. In the current study, a process model was built using HSC Sim software, and metamodeling of the simulated flowsheet was conducted with the design of experiments (DOE), after which the basic functionality of the flowsheet was verified by experimental work, starting from sulfuric acid leaching of spent batteries. As the process is based on chemical circulation internally in the process, the objective was to investigate the accumulation of the elements in solution, specifically Na+ , K+ , SO4 2− ions and impurities liberated in the NaOH conversion step. It was found out that metamodeling could be utilized in obtaining first estimate of the process behavior, prior to any experiments. Flowsheet functionality with circulated solution was confirmed, obtaining at best 96.9% La recovery.

By K. E. Yassin, A. Yehia, M. Amar

Phosphate fines (size ≤ 45 μm), from the Red Sea Region, Egypt, were subjected to beneficiation process to recover the phosphorite grains from such fines. The sample is characterized by low P2O5 content (18.78%) associated with gangue minerals such as silica (22.77% SiO2) and carbonate (2.01% MgO) indicating its low grade. Phosphate pre-concentrate was prepared by gravity separation, using Falcon, where 63.37% of the phosphate, with 24.94% P2O5, 1.46% MgO, and 10.54% SiO2, was firstly recovered reducing the mass flow to the subsequent beneficiation process. However, the gravity tailing was the feed for the reverse phosphate flotation using bench scale column flotation where oleic acid was used as a carbonate gangue collector and amylase enzyme as a phosphate depressant. Under the appropriate flotation conditions (0.1% amylase, 5·10−4 mol/dm3 oleic acid, and temp. 30 °C), phospho-concentrate assaying 0.61% MgO, 13.14% SiO2, and 27.85% P2O5 with a P2O5 recovery of 55.45%, was finally obtained without the use of expensive depressants, e.g., phosphoric acid or sodium silicate. A tentative flow sheet for the whole process was postulated.

By Lawrence Addicks

T HIS has been a most momentous year in the annals of the Institute. We have been in the midst of a situation which, were it not for the convulsions of social unrest with which life is surrounded on every side, would have attracted the attention of the world at large. I do not refer to the desperate campaign for new members. That has gone on much as usual except that, this being leap year, the annual proposal to the M. & M. Society has been omitted. Nor do I refer to the desperate situation which we found in other directions, the spread of Bolshevism, the burning of the Engineers' Club, the fact that the selling of copper appears to have become one of the lost arts. No, I speak of the great question which has to be. settled once and for all, as to whether this great Institute should adopt simplified spelling. The whole trouble started in the ranks of the California Hysterical Society. It appears, while most of the San Francisco members can read and write, several of them cannot spell. It also appears that the Secretary, in editing the Transactions, has perhaps made just a little bit too much of a point of employing the correct Stoughton idiom. At any rate, the rebels filed an amendment to the constitution, and the stage was set for civil war, with perhaps more stress on war than on civil.

Jan 1, 1920

By D. M. Walters

To achieve safe and healthy working conditions in shaft sinking operations, ventilation, and where necessary cooling, must be provided. These requirements are considered for sinking vertical, sub-vertical and decline shafts. Regulatory requirements, determining air volumes and amount of cooling required, the various ventilation methods used such as force, exhaust, twin columns, air reversal using four gate systems and the equipment required to achieve this, are discussed. Consideration is also given to the sinking of single and twin declines using diesel equipment, calculating the air volumes required to dilute pollutants and the various methods for achieving this. Also discussed is the importance of having early ventilation design input to the overall design of the mine. In many cases ventilation can be the prime determinant for the size and configuration of the shafts or declines that have to be sunk.

Jan 1, 2009

By Jack S. Watson, Rasika Nimkar, Robert M. Counce, Matthew Gordy, Patrick Zhang

Waste phosphatic clay presents a difficult disposal problem and a significant loss of P2O5. Recent developments make this study on the use of phosphatic clay as a feed material for H3PO4 production worthwhile. (a) New data from Florida Industrial and Phosphate Research Institute (FIPR) suggest that the Bclay^ waste can be effectively treated by improved solid separation coupled with flotation to produce feed material for recovering additional phosphate. (b) The use of BOLI Flowsheet^ provides capability to predict performance of aqueous-based processes for a range of possible operating conditions. Using the new FIPR data and BOLI Flowsheet^ enabled the design of a new process that can potentially extend the usefulness of current P2O5 ore deposits. Predictions using OLI Flowsheet were able to identify process conditions that effectively overcome the difficulty of high Mg content of phosphatic clay. Estimated manufacturing cost in the current study lead to valuation of the P2O5 content of the phosphatic clay recovered/utilized at 60 to 70% of that of the phosphate rock feed material currently used. Phosphatic clay should be considered as a valuable material that is currently given zero value. The new FIPR data and BOLI Flowsheet^ enables the design of a new process that can potentially extend the usefulness of current phosphate ore deposits by extending the fraction P2O5 of recovered

By Colin Lindsay

"The Collahuasi copper mine, located at an altitude of 4300 meters above sea level in northern Chile, commenced operations late in 1998. The mine is currently the 4‘h largest copper producer in the world and comprises an open pit, a 60,000 tpd sulphide concentrator, a 15,000 tpd oxide heap leach and SWEW plant and a 200 km concentrate pipeline to a port facility.Constructing, commissioning and operating a mine at high altitude presents unique challenges in terms of the performance of both equipment and people. It is important that these be recognized and carefully considered during the feasibility study and the detailed design stages and the success of the Collahuasi project is largely due to this. The plant design incorporates a number of features aimed at mitigating the problems of altitude and the construction methodology also took into account the particular site conditions.This paper discusses the Collahuasi project team’s approach to planning for the remote location and also some of the problems experienced during construction, commissioning and operation.INTRODUCTIONThe Collahuasi mine is located in northern Chile, some 250 km to the south-east of the port of Iquique and 15 km from the Bolivian border. The mine facilities lie between 3800-4300 m above sea level on the Altiplano, the central plateau of the Andes mountains, and cover a total of approximately 95,000 hectares. Although the area is arid, it experiences an average of 150 mm of precipitation annually and weather conditions can be extreme. Temperatures during the day range between -3 to +11 º C and are generally below 0ºC at night, sometimes as low as -20°C. High energy winds are common and humidity is low. Much of the precipitation occurs during the winter as snow but there also occurs a period during the Chilean summer known as the “Invierno Boliviano’’ (or Bolivian Winter) which is characterized by severe electrical storms and rain."

Jan 1, 2001

By R. Melley, P. Wissner

The paper looks at the basic theory of tri-bological wear and the role played by the lubricant and its additives. It presents the argument that the “real cost of lubrication” is not the purchase price of the oil or grease, but rather the costs associated with not using the correct lubricant. A number of examples are presented, covering oils, greases and additives, in which a detailed evaluation of the application has shown that when all of the benefits of using the best lubricant/additive are evaluated, the savings achievable greatly surpass the incremental cost of the superior lubricant. One of the emerging classifications of costs in industry today are those associated with environmental protection. Two of the examples used describe the replacement of more conventional lubricants with environmentally acceptable products, compounded to compete in all aspects of serviceability, but which have the added bonus of being not only biodegradable but also of being of low toxicity.

Jan 1, 1997

By Peter Moser, Mark Ganster, Andreas Gaich

Surveying of a bench face before blasting is a pre-requisite for a proper blast planning and for a satisfying blasting result both in terms of safety and fragmentation. When surveying a bench face, preferably a large amount of measurement points are required in order to determine the geometry and especially the irregularities with sufficient accuracy. Only contact-free measuring systems allow evenly distributed measurements over the whole bench surface. Existing systems such as total station, laser profiler, or laser scanner show significant drawbacks such as that surveying results are just isolated values of the bench geometry such as heights or profiles, that borehole positions have to be defined in advance in order to know where to take profile measurements and that systems require special surveying skills and that they are expensive too. In order to overcome these difficulties and to provide the blasters a simple tool for bench surveying, blast design and layout and the subsequent back-transfer of the blast plan into the quarry, the Department of Mineral Resources& Petroleum Engineering of the University of Leoben, 3G Software & Measurement company and Mineral AB, one of the largest producers of aggregates in Europe formed a joint venture to develop a new system. Based on an existing stereophotogrammetric system for rock surface surveying and joint analysis (JointMetrix), a new tool was developed within a year. Apart from several mines and quarries using that new tool already today in the daily work, both the Department of Mineral Resources& Petroleum Engineering at the University of Leoben and Austin Powder GmbH Blasting Service did a lot of studies to determine the reliability of the new stereophotogrammetric blast surveying and planning system and its precision in comparison to classical laser surveying equipment. After 1 year of testing and comparison with laser based surveying instruments, it can be concluded, that the new technology of blast surveying& design systems based on stereophotogrammetry is suitable for being used in the daily work routine in quarries and mines. The comparison of the precision of laser based systems and stereophotogrammetric systems has shown, that the deviation between these two types of systems is less than 10 cm, in many cases even lower.

Jan 1, 2007

By Sushil Bhandari, Amit Bhandari

Blast optimization in open-pit operations is a task that often remains at a theoretical stage. Indeed, when it comes to operational blast design and onsite implementation, time restrictions and field conditions make it difficult to execute a planned pattern accurately and optimization according to local conditions is even more difficult. For example, adjusting a drill pattern to a complex face geometry is not something that can be easily undertaken on site. Blasters and engineers will do their best trying to distribute boreholes over the bench and even then, it can take them hours to achieve an acceptable layout. Similar situations occur with delay sequences, when trying to adjust them to address selectivity or vibration issues. For these reasons, operational blast design will often remain at a very basic level and the required adjustments are laid aside due to the difficulty of implementing them on site.

Jan 1, 2019

By W. E. Falck, A. Usubiaga, J. Spangenberg, P. Schepelmann, S. Šolar, D. Wittmer, F. Blanchard

The extraction and processing of mineral resources may be accompanied by environmental impacts. In spite of technological advancements, the enormous increase in production volumes within the last decades has induced sizeable environmental impacts along the life-cycle of products. Beside environmental impacts, social issues associated with mining need to be considered to ensure the social acceptability of mining activities. The project EO-MINERS aims at deploying Earth Observation (EO) tools to inform best practices in mining and to thus assist the global mineral resources industries in their transition to sustainable development. In order to facilitate the handling of complex sets of information requirements from a wide variety of stakeholders, a set of indicators was developed that will inform the process of EO tool and services development. The project strives to enable stakeholders outside the industry to meaningfully participate in decision-finding processes on mining-related issues by developing and providing EO products and services that fit the information requirements. The project has identified a wide range of such information requirements by stakeholders that could be potentially provided by EO tools. The applicability of the EO tools on the local level is tested on three mining sites.

Jan 1, 2011

By E. S. Leaver

The gold that is not recovered by a particular process is refractory to that process. A study to determine how the refractory gold is associated in the ore constituents usually indicates the needed improvement in the process or additional methods for bettering recovery. In preliminary work, segregation of the various minerals, gangue or impurities, and data showing the reactions of each in the recovery method readily confines the refractory gold to a certain part on which extensive research can be directed. In this dissecting plan, the microscope is an important aid in locating the refractory gold but should be supplemented by chemical tests.

Jan 1, 1934

By F. N. F. le Roux

This paper describes the method used for excavating the upper 33m of emergency access shaft E2 for the underground single track tunnel running between Park and Rosebank station of the Gautrain Rapid Rail System. The soil was decomposed shale and diabase from the Witwatersrand Supergroup. The location was in the car park of The Wilds (a public park) in Johannesburg. The method proved very simple and required less complex plant and equipment than normal when excavating the shallow soil sections in shafts. It involves driving steel sheets ahead of the shaft sump into the soils and then excavating inside the ?tub? created by the sheets whilst supporting the sheets above with regularly spaced circular Steel Rings. It is the intent of this paper to discuss the method and design approach to the method. This will be done at the hand of experiences at E2 shaft..

Jan 1, 2009

By F. N. F. le Roux

This paper describes the method used for excavating the upper 33m of emergency access shaft E2 for the underground single track tunnel running between Park and Rosebank station of the Gautrain Rapid Rail System. The soil was decomposed shale and diabase from the Witwatersrand Supergroup. The location was in the car park of The Wilds (a public park) in Johannesburg. The method proved very simple and required less complex plant and equipment than normal when excavating the shallow soil sections in shafts. It involves driving steel sheets ahead of the shaft sump into the soils and then excavating inside the ?tub? created by the sheets whilst supporting the sheets above with regularly spaced circular Steel Rings. It is the intent of this paper to discuss the method and design approach to the method. This will be done at the hand of experiences at E2 shaft..

Jan 1, 2009

By H. Tomlinson

"INTR0DUCTIONThis publication is a third of a series devoted to falls of roof and coal in coal mines of the Western States. It gives the results of examinations of the mines of the Rock Springs coal District of Sweetwater County, Wyo., which represent the principal coal beds therein and approximately 75 percent of total production of the State.A study was made of safety conditions at all the producing mines of the district and suggestions were offered the operators regarding methods and practices which would, in the opinion of the writer, provide additional safeguards to prevent accidents from falls of roof and coal.In presenting the subject, consideration must be given to such features as character of the coal beds, depth of cover. methods of mining, timbering practice, roof testing and supervision, and for comparative purposes to certain statistical matter bearing upon relation of accidents to their causes, tonnage produced, men employed, days worked, and lost days due to accidents during the 3—year period covered by this study.ACKNOWLEDGMENTSThe writer acknowledges the cooperation of the officials of the various coal companies, without whose assistance this work could not have been completed.F0UR REPRESENTATIVE COAL OPERATIONSThis report relates to four representative coal operations in the Rook Springs district of Sweetwater County, Wyo., which are referred to as mines A, B, C, and D. This group employs yearly an average of 993 men, representing 37 percent of the men in coal mines of the county, and has an average annual production of 1,484,373 tons, representing approximately 44 percent of the coal produced in the county. Figure 1 is a map of the Rook Springs coal district."

May 1, 1933

By E. R. Bauer

In response to the mandates in the MINER Act of 2006, NIOSH conducted refuge alternatives research that included characterizing the utility, practicality and survivability of refuge chambers and outby safe havens. NIOSH also prepared and delivered a report to Congress in late December 2007 that summarized the findings of the research, included recommendations concerning the design and performance specifications for refuge alternatives, and focused on specific information that could inform the regulatory process on refuge alternatives. This document highlights NIOSH's research and recommendations concerning refuge alternatives, survivability evaluations of refuge chambers, and presents a brief review of the current deployment of refuge chambers in underground coal mines in the U.S. The research has lead to the conclusion that refuge alternatives have the potential for saving the lives of mine workers if they are part of a comprehensive escape and rescue plan, and if appropriate training is provided. DISCLAIMER: ?The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.?

Jan 1, 2009

By T. Stauffer, B. McGunegle, A. Adu-Acheampong

The Fairmount Minerals, Inc., Maiden Rock underground sand mine historically delivered air to ventilate diesel-powered equipment at its working faces through high-resistance, 15-inch-diameter PVC distribution lines. In support of plans for expanded production, three new, low-resistance ventilation design alternatives were analyzed. The study determined that adequate ventilation for expanded production was possible with various commercially-available, high-volume/low-pressure fans combined with a systematic layout of control structures. The recommended re-design was implemented in 2001, resulting in a significant increase in flow volumes and a noticeable improvement in the mine environment.

Jan 1, 2007

By Scott Martin

This paper will discuss the challenges currently facing the mining industry. By sharing experiences gained in the CIM Leading in Mining Course, I will highlight what’s working, what’s not, what are the challenges, what are the concerns, what are the opportunities, what needs to happen. Specifically, I will discuss what is currently happening with leadership and leadership development in members’ own organizations, what skill sets are important to develop in different hierarchical groups and how comprehensive leadership courses like the leading in Mining course can help improve leadership within individuals and the industry. Leadership development is a process not an event.

Jan 1, 2014