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By D. Visser

This paper is based on the Townlands Ore Replacement Project whereby the concept of conventional sinking of one large diameter shaft was declined and replaced with three smaller raise bored shafts. A wire line geophysical survey was done and the results indicated that a single shaft larger then 4 m diameter unsupported would not be suitable. The shafts were placed 28 meters apart measured from centre to centre. To ensure that the skin to skin pillars between the shafts remained regular and to minimise any deflection, the pilot holes were drilled with the Rotary Vertical Drilling System. The different shaft sinking methodologies are discussed explaining the risk associated with each method.

Jan 1, 2009

By D. Visser

This paper is based on the Townlands Ore Replacement Project whereby the concept of conventional sinking of one large diameter shaft was declined and replaced with three smaller raise bored shafts. A wire line geophysical survey was done and the results indicated that a single shaft larger then 4 m diameter unsupported would not be suitable. The shafts were placed 28 meters apart measured from centre to centre. To ensure that the skin to skin pillars between the shafts remained regular and to minimise any deflection, the pilot holes were drilled with the Rotary Vertical Drilling System. The different shaft sinking methodologies are discussed explaining the risk associated with each method.

Jan 1, 2009

By D Olivier

De Beers' Finsch Mine is situated in the Northern Cape province, 170 km northwest of Kimberley. The concentrator facility, designed and constructed by Bateman Engineering, was commissioned in 1967 and upgraded in 1979 using diamond liberation and extraction technology available at the time of design. Since then significant advances in diamond processing and technology have been made and these -have been incorporated into the new main treatment plant and recovery plant flowsheets, making diamond liberation and recovery from the Pre-1979 dumps a viable economic option at Finsch."

Jan 1, 2010

By D. Hu, J. Xu, N. Liao, C. Wu, J. Ye

The vertical stirring mill’s fine grinding equipment is affected by the operating conditions during the grinding process. The grinding media has a great influence on the energy consumption and particle size distribution. This paper investigates the fine grinding performance of nano-ceramic balls and steel balls of the same weight for magnetite by a wet grinding process in a vertical stirring mill, where 15 mm nano-ceramic balls and 12 mm steel balls are used as grinding media to carry out batch grinding tests. We have observed that the newly qualified particle content of the nano-ceramic balls is higher than steel balls of the same weight at the same specific energy. The reason may be the advantage of a greater surface area and volume filling rate with the nano-ceramic balls. Moreover, the specific energy of nanoceramic balls is less than steel balls of the same weight under the same grinding fineness. In addition, energy efficiency indicates that the nano-ceramic ball has a higher energy efficiency than a steel ball of the same weight. This is due to the light bulk density of nano-ceramic balls. The application of a nanoceramic ball in a vertical stirring mill will improve iron ore grinding performance. Keywords: Steel balls, nano-ceramic balls, vertical stirring mills, fine grinding, particle size distribution, energy consumption

Jan 1, 2020

By I. V. Filippova, Y. Foucaud, M. Badawi, L. O. Filippov, S. Lebègue

To optimize the flotation of Ca-minerals, their separation contrasts were investigated by coupling experimental and theoretical techniques. We showed that they mainly rely on structural properties such as the Ca-Ca distance on their exposed surfaces but also on the ability to control the intermolecular interactions. An optimized composition of the carboxylic collector by calculating the collector-mineral and the intermolecular interactions was developed. Blending the saturated acids and non-ionic molecules with a fatty acid collector significantly increases the flotation selectivity between scheelite (CaWO4) and fluorite (CaF2). The theoretical results were validated by experimentally improving the separation contrast between Ca-minerals. After the tests of several depressants and collectors, the best depression of gangue Ca-minerals (fluorite, apatite and vezuvianite) was found by combining sodium silicate and sodium carbonate. Keywords: Ca Minerals, Fluorite, Scheelite, Carboxylic acids, Unsaturated Acid, Fatty acids

Jan 1, 2020

By F. S. Hoseinian, B. Rezai, E. Kowsari, M. Safari

In order to remove heavy metal ions from a large volume of wastewater with a low ion concentration, ion flotation appears to be promisingly effective. In the ion flotation process, because of the high ion removal percentage, the amount of water recovery percentage is a very important factor which determines the process efficiency. However, ion flotation suffers from relatively high collector concentration to achieve the high removal percentage to the desired limit, which subsequently increases the water recovery. In this study, functionalised graphene oxide (FGO) was synthesised, using a chemical method in the ion flotation process, applied as a collector for increasing process efficiency by reducing the collector consumption and water recovery. The high ion removal was achieved with both collectors of sodium dodecyl sulfate (SDS) and FGO, while the water recovery with a collector of SDS was 3.4% higher than that with a collector of FGO. The results indicated that the FGO could be effectively used for high ion removal and low water recovery in the ion flotation process. Keywords: Ion flotation, synthesised collector, ion removal, wastewater, water recovery

Jan 1, 2020

By X. Cao, R. Wang, H. Han, Y. Hu, Z. Wei, W. Sun, H. Tang, J. Wang

Flotation reagents play a vital role in mineral flotation. In the past century, most studies focused on the modification of anion or cation collectors and the synergistic effect of mixed collectors, which have contributed to research. In this study, we reviewed brand-new reagents, metal-organic/inorganic complexes, with the functional group of metal ion, which are totally different from the traditional anion or cation collector and show absolute specificity for some minerals. For example, Pb-BHA complex collector was developed to realise the atmospheric flotation of scheelite due to the absolute specificity for calcium minerals. Calcium oleate collector was found to be the effective species in the flotation of calcium minerals, and has been employed to selectively separate fluorite from calcite. Selective adsorption of Al-Na2SiO3 polymer on calcite surfaces proved the self-assembly of H2SiO3 polymer using Al3+ had stronger selectively adsorption ability than Na2SiO3. Also that Fe3+-starch complex was a better depressant for iron minerals than caustic starch and contributed to a more efficient reverse flotation. In conclusion, metal ions are good templates for molecular assembly and can be used to control the structure of metal complexes and exhibit special properties, which provide possibilities for the design of new flotation agents. Keywords: Metal-organic/inorganic; flotation; collector; depressant

Jan 1, 2020

EMMES Sampling Conference BACKGROUND & INTRODUCTION ?Impala acquires toll material to supplement production from ROM ?Toll material consists of filter cake, slurry and catalysts ?Samples are collected to determine the commercial values of the lots ?Slurry deliveries projected to remain relatively constant at 120tons dry solids per month, whereas filter cake deliveries set to increase five-fold to 800 tons dry solids per month ?Due to projected increase in toll material, new sampling and offloading facility presently under construction at Impala ?Presentation will cover two projects aimed at reducing the uncertainty associated with sampling of toll deliveries ?i.e. slurries and filter cake.

Jan 1, 2005

By G. Sánchez, S. Seiler, B. Klein, T. Cebeci, P. Bradshaw

The Decar Nickel District is a greenfield discovery by FPX Nickel Corp., of nickel mineralisation located in central British Columbia (BC), Canada. The Baptiste deposit is part of the Decar Nickel District and is a unique deposit containing a nickel-iron alloy mineral called awaruite, with over 2-billion tonnes of inferred resource grading 0.12% Davis Tube Recoverable (DTR) nickel. This deposit represents a significant nickel resource. Awaruite is a high density and ferromagnetic mineral, which could be recovered, along with magnetite that is also present in the samples, using magnetic separation. However, there is still a lack of understanding of the properties of the awaruite and its metallurgical response. This information is imperative for the set-up of the variables involved in its concentration. The aim of this paper is to show and discuss the effect of magnetic field strength for the recovery of nickel from Baptiste deposit samples. Magnetic separation at bench and pilot scale with different magnetic field strengths is evaluated as a concentration method for awaruite. Mineralogical information is provided to support the results and also to briefly assess the variability of DTR nickel within the deposit. The Baptiste deposit is unique and will benefit from a sound scientific understanding of the process solution as well as other ongoing work. If successful, the outcome will lead to the development of a mine. With greater than 2-billion tonnes of inferred resource, the mine would represent a significant new source of nickel globally. Keywords: Nickel ore processing, magnetic separation , awaruite, magnetite

Jan 1, 2020

By S. Banisi, A. Ghasemi, A. Fazeli, M. Rezaei, M. Maleki-Moghaddam

The efficiency of high capacity SAG mills which consume large amounts of energy depends on the grinding and slurry discharge systems. A 9.7 m × 4.8 m SAG mill with radial pulp lifters is used at the Sarcheshmeh copper complex grinding circuit. The process audit indicated that the pulp discharge system was not efficient, judging by the amount of slurry flow back and carry over. These events limited the discharge rate and increased the wear rate of the lifters and grates. With the objective of finding a new design for pulp lifters, a 3D DEM software (KMPCDEM ©), along with the plant operational data and photographic evidence was used. The KMPCDEM © software was used to compare the efficiency of the radial and curved pulp lifter design based on the material flow. The slurry flow was analysed in terms of ease of discharge and lifter wear rate. It was found that changing the radial pulp lifters to curved pulp lifters could improve the discharge efficiency,and decrease wear rate of the pulp lifter in particular at the base of the pulp lifters. The simulation results showed that if curved lifters with a radius of 0.3×mill radius are used, the amount of slurry flow back and carry over will be negligible. It is predicted that by installing the curved pulp lifters, the capacity of the mill increases by 10% and the pulp lifter service life improves by at least 20%. Keywords: SAG mill, radial pulp lifter, DEM,curved pulp lifter, Sarcheshmeh

Jan 1, 2020

By M. Kumral, S. Li, M. Balci, Z. Shao

Main haulage roads play an important role in the performance of underground mines because of the cost of transportation of the extracted ore, equipment, and workers. During mine development, these roads are designed through manual tools or CAD-based software. However, the optimisation of these roads is still a complex problem due to some constraints such as minimum turning radius and maximum gradient. By utilising Dubins path theory, three elevation cases; namely low, medium and high are defined, considering gradient constraint as well as the minimum turning radius in a three-dimensional space. The shortest path between two points can then be found by the three-dimensional Dubins path algorithm with elevation constraint. As a further step, a three-dimensional Dubins path algorithm with elevation constraint for multiple points is also developed for multi-point cases. The effectiveness of these algorithms is tested through case studies in order to determine the optimal path between different points.

Sep 1, 2021

By M. M. Makhofane

Anhydrous zirconium tetrafluoride can be used as a precursor for the manufacturing of nuclear-grade zirconium metal. This can be done by fluorinating plasma-dissociated zircon with ammonium bifluoride in a batch reactor. This paper describes the batch process. It was proved that anhydrous zirconium tetrafluoride can be manufactured by this route as confirmed by X-ray diffraction. The process shows potential for scaling up to the kilogram scale and possibly the tonnage scale.

Jan 1, 2012

By C. B. Carelse, M. Manuel, D. Chetty

Automated mineralogical analysis of platinum group minerals (PGM), using the mineral liberation analyser, provides information used to understand flotation efficiency, primarily from a PGM liberation and association standpoint. To date, however, there is no consistent understanding regarding PGM speciation and its impact on floatability. Previous studies of PGM from UG2 ores concluded that a larger dataset is needed from which the various parameters can be modelled. Parameters on telluride, arsenide, sulfurarsenide and alloy species need to be integrated to fully understand the impact of PGM speciation on flotation, and for this, ores other than PGE-sulfide-rich UG2 must be assessed. Flotation rougher rate tests were performed on feed samples from two Platreef ores to determine the flotation response of individual liberated PGM species. This was achieved through automated mineralogical analysis of feed, rougher concentrates and tails. Based on 1529 liberated PGM grains assessed over the circuit for two Platreef ores, preliminary results show that PGM speciation, species grain size and competition from gangue appear to influence floatability in an ‘optimised’ laboratory environment. Keywords: PGM, PGM species, flotation, liberation

Jan 1, 2020

By R. Van Deventer

The BIOX® process was developed for the biological pre-treatment of refractory gold ores and concentrates ahead of conventional cyanide leach gold recovery. Rights to the process are currently with BIOMIN Technologies SA, a subsidiary of Gold Fields Limited. There are currently eight operating installations worldwide employing the process on a commercial scale. EKATO is a company specializing in developing new or optimizing existing mixing applications. EKATO has acquired a vast amount of expertise in agitation over its 75 year history. In a joint research project the reactors of the BIOX® process were characterized from the aspect of their mixing performance. BIOMIN is constantly testing new mixing solutions and reviewing potential vendors to increase the efficiency of the BIOX® process. EKATO?s intention was to qualify as an approved vendor for supplying agitation equipment to the BIOX® process. A two step approach was planned: In phase one of the project EKATO would develop an alternative agitation solution to the established option, exhibiting at least similar performance levels. In phase two potential possibilities to improve the overall design would be developed. This paper focuses on phase one and addresses the systematic approach applied by EKATO in characterizing the mixing processes. Mixing tasks were assessed individually applying basic theory and scale-up and -down rules to the individual tasks. Testing with model systems was done at the EKATO technology center in Schopfheim, Germany, on scales of 50 liters and 1 m³. The results showed that the ISOJET-B impeller design showed promising performance under BIOX® reactor conditions. Scale-up with the ISOJET-B was done in order to apply it in the 21 m³ live volume test reactor at Fairview mine in South Africa. At Fairview tests were performed using model systems and eventually under real plant conditions with BIOX® slurries. The results were a success and confirmed that the scale-up factors determined during the testing at EKATO?s technology center could be substantiated in the ?model scale? 25 m³ reactor. Testing under the actual process conditions showed that all design parameters were within the desired range to be considered an excellent leaching performance. This successful joint development shows the importance of a close cooperation of technology licensors or end-users and equipment suppliers. It is vital for understanding all factors influencing the mixing performance of processes. Exercises such as this will provide equipment suppliers and plant operators more confidence in managing further scale ups at ever larger engineered plants.

Jan 1, 2009

By H. Uygucgil, C. Kwang

The use of remote sensing and geographic information system techniques in mineral exploration is still underutilised. There is a need to explore the potential of new robust remote sensing and geographic information system techniques in the field of mineral exploration. In this study, we mapped the argillic alteration associated with epithermal gold-silver mineralisation. A band ratio of band5/band6 and Crósta technique on Advanced Spaceborne Thermal Emission and Reflection Radiometer within the Google Earth Engine Environment was applied. The bands 5 and 6 were selected for the band ratio after critically analysing and comparing the illite spectral extracted from the Advanced Spaceborne Thermal Emission and Reflection Radiometer image and the illite spectral obtained from the United States Geological Survey spectral library. The band ratio and Crósta technique identified and mapped the Ovacik goldmine and other argillic alteration zones. Even though both methods mapped out the argillic alteration zones associated with gold-silver mineralisation, the Crósta technique produced the optimal argillic alteration. The study demonstrates the analytical capabilities of Google Earth Engine in image processing and analysis for mineral exploration, such as discovering hydrothermal alteration associated with mineralisation.

Jul 23, 2025

By P. de A. Barbosa, M. G. Bergerman, E. da Fonseca

Located in the state of Pará, Brazil, the Sossego copper and gold mine consists of a heterogeneous geological deposit. Its complexity derives from the hydrothermal alteration, the ore-forming event, which modified the host rocks, such as granite, and metamorphosed volcanic rocks into several mineral assemblages. Different mineral assemblages have led to differences in abrasiveness. A few Bond abrasion tests conducted during the mine feasibility study did not provide a robust abrasiveness database, thus the variation of physical properties for some mineralisation host rocks was not possible. Although several test methods may be used to determine ore abrasiveness, the Bond method is the one most commonly used in the mining industry. Despite being simple to carry out, this test method has certain limitations as to particle size and the amount of ore sample required, which often makes it difficult or even impossible to apply in the early stages of a project and in geometallurgical studies. The Laboratoire Central des Ponts et Chaussées (LCPC) test may provide an alternative, as it requires a smaller amount of fine-grained material. This study aimed to provide data on wear properties of various ore types from Sossego mine using the LCPC method. It included validation for 40 different ore samples using the Bond test as a benchmark. The results showed good correlation, indicating it may be possible to use the LCPC test as an alternative to the Bond abrasion test. A high abrasiveness index was found for acid metavolcanic rock, confirming the results observed in Sossego mill’s operating database, pointing to a mineralogical drive to amorphous quartz. Keywords: Abrasiveness, geometallurgy, copper ore, Bond abrasion test, LCPC

Jan 1, 2020

By G. de Tomi, G. C. Teodoro, E. Rodovalho, T. M. El Hajj, J. A. S. Tenório

The selection of an underground mining method stems from a multivariate analysis that considers geomechanical, geological, economic, and operational parameters. Even after identifying the most compatible method, there is no assurance that the mining company will achieve the best performance. The geological complexity of some deposits requires adaptations of methods described in the literature to obtain more selectivity and reduce mining waste. There are some studies on geometry of underground structures, but a methodology that describes an adaptation of a room-and-pillar mining method for ore bodies with down-dip varying from 20° to 25° is novel. The present work aimed to reduce dilution by adapting the traditional room-and-pillar mining method (TRP) to inclined ore bodies. This new method is entitled short-hole room-and-pillar (SHRP). The equations that measure the dilution are defined according to the geometry of stopes and openings. The results comprise comparative analyses of the operational and planned dilutions to measure the performance of the SHRP method. The average operating dilution of the SHRP method was more than five times lower than the planned dilution according to the TRP method. Low operational dilution indicates high selectivity of the method and its potential to reduce underground mining tailings.

Sep 9, 2024

By N. Naude, R. Foisy, F. Bornman

Spiral separators have been widely accepted as one of the most flexible gravity separation devices for several decades. The International Journal of Mineral Processing, 84, pp. 118 – 132 mentioned that spirals are for treating material too coarse for flotation and too fine for dense-media separation. Powder Technology V 102, pp 244 – 252, 1999 stated that there exists a genuine need for extending the performance envelope of spirals – whether to treat finer or coarser material than the traditional size ranges. In recent times there has been an upsurge in interest, particularly in the development of newer fine gravity separators. Spiral separators for the recovery of ultra-fine particles have a unique profile, pitch and features to ensure efficient performance. The flow on the spiral trough must be controlled to minimise turbulence that will entrain fine particles in the outer section of the trough. The experimental test work showed a movement of mass from the outer region towards the centre column of the spiral, i.e., from the fine tailings band towards the concentrate. As recovery on the spiral trough is a function of mass yield and grade, the ultra-fine 7 spiral had a better recovery than the HX5. This makes the UF7 an ideal rougher spiral. Keywords: Ultra-fine particles, spiral, design, recovery

Jan 1, 2020

By T. Bhambhani, J. Jankolovits

Sphalerite flotation using copper sulfate has been performed in the industry for decades and the mechanism of Cu activation is well established. Despite its ubiquity, many practical questions surrounding copper sulfate persist. It is not clear how iron selectivity is achieved in zinc circuits given the propensity of iron sulfides to be activated by copper. Also, the large variation in copper sulfate dosages across different plants and ore types cannot be explained. Lastly, Zn flotation with greatly reduced copper sulfate dosages attracts significant interest and has been demonstrated in certain laboratory settings, but no information is available on why those laboratory solutions have not been adopted in plant practice. Flotation studies are presented that demonstrate that Zn flotation with very low copper sulfate dosages is possible when using certain novel collectors that are not practised in the industry. However, these reagent schemes are impractical because of a heretofore unappreciated and critical role that copper sulfate plays in Fe rejection. With both very low and standard copper sulfate dosages, copper sulfate influences both Zn flotation and Fe rejection. The results highlight the multifaceted role of copper sulfate in zinc flotation and the need to holistically consider complex systems’ behaviour to understand flotation reagent mechanisms and optimise plant performance. Keywords: Sphalerite flotation, metal activation, copper sulfate, iron rejection

Jan 1, 2020

By Pentti Niskanen

"The ventilation system of the Pyhasalmi Mine is described. The mine is located in an area where the annual atmospheric temperature may vary from +30°C to -30°C. Natural ventilation causes serious difficulties because the underground mine is connected by drifts and finger raises to the bottom of the 120 m-deep open pit.The natural ventilation tends to make the ventilation net unstable. The paper describes how the instability characteristics of the ventilation net can be studied and how they have been taken into account when automating the control of the ventilation. In addition, the software, hardware and costs of the system are described. The system consists of 12 automated ventilation doors, two mine fans, 8 elements for sensing the air flow and temperatures, a control panel and a process computer."

Jan 1, 2014