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By M. Le Roux, Q. P. Campbell, N. Hughes

Water plays a significant role in minerals processing; this is especially true in coal preparation where water-based beneficiation is widely accepted and consistently delivering sharp separation efficiencies and high product yields. Although wet processing is favoured, the substantial process water requirement may prove this impractical and unsustainable in some parts of the world. Many coal-rich regions (including South Africa) have experienced severe water shortages. Coupled with the effects of drought, some countries experience freezing winters from which problems related to frozen process water and machinery may arise. Hence coal preparation practices will soon have to adapt, irrespective of the technical and economic feasibility offered by the currently employed water-based methods. As a result, extensive research into the development of dry methods for effectively beneficiating coal has progressed. This review paper intends to provide a collection of the relevant information pertaining to dry coal processing globally, and aid in understanding the applicability, performance, success or failure thereof. The methods available for dry materials preparation, with special regard to those applicable for coal beneficiation, are detailed in terms of principle, applicability, limitations and performance. Dry coal beneficiation has potential to aid the current wet-based methods with some considerations to possible limitations set forth by coal geology, application, product specification, particle size distribution, moisture, efficiency, capacity and cost. These methods may be established in future, especially in the arctic, arid and under-developed regions through new plant installations, expansions and small mines processing. Keywords: Dry coal processing, preparation, cleaning, beneficiation

Jan 1, 2020

By C. A. Rawlins

In an underground mine the ingress of heat can generally be attributed to two sources (Rock exposure and artificial mechanisms). The heat load relating rock exposure is subdivided into stoping [~40%] and haulages [~20%]. Rock is exposed to the ambient air and as a mine increases in depth the VRT (Virgin Rock Temperature) increases which leads to more heat ingress underground. To counter the heat ingress, especially in low-seam stoping areas of a deep level mine, air is, a) cooled artificially, b) the amount of rock exposed is reduced in the back areas of a stope by backfill applications, and c) ventilation air is used more efficiently. The heat reduction within a stope due to placed backfill could amount to ~50% for operations mining at a mean rock breaking depth of about 4500 mbc (metres below collar). Unfortunately, due to backfill transport methods, the physical fluid properties and application methods adopted, additional heat is induced into the air. The heat ingress due to backfill application could amount to as much as 25% of the overall in-stope heat load. This heat influx, seen as a negative aspect of backfill operations, is nevertheless overshadowed by the overall in-mine heat load reduction capability of about 20% attainable. The in-stope benefit [~50%] attainable from backfill operations could be increased with the incorporation of a heat exchange (cooling) methodology to offset the additional heat ingress into the surrounding air of a deep underground mine.

Jan 1, 2003

By A. Ennen, R. Wagner, B. Orberger, J. -M. Milazzo, N. Uhlmann, J. Banchet, J. Lucic, N. Wörlein, M. Firsching, J. L. Dubos, C. Bauer

The residues from mining and processing ores can often be considered as secondary raw materials. However, the material is only available in the form of fine particles (< 3 mm). In order to recycle these wastes, it is necessary to agglomerate it for transportation prior to reprocessing. The resulting agglomerates need to mechanically resist the stress of transportation and loading into the furnace. X-ray computed tomography (CT) is an established method for characterisation of internal structures in material science. This non-destructive technique can provide information on size and distribution of particles and grains. However, the information is not limited to the size, but also can yield structural features like orientation and position of cracks and fractures, which are important features indicating potential for deteriorating the agglomerates. Furthermore, deduced features such as contact conditions of inclusions or boundary surfaces can also be calculated. We studied binder-free tablets of manganese-oxyhydroxide, bentonite, kaolinite and slag powder using micro-CT. Inclusions of highly absorbing particles were identified using a watershed transformation with automatic segmentation by Otsu thresholding. Subsequently, the resulting data was analysed regarding their volume percentage, distribution in size and location within the sample. For the slag agglomerates, the volume fraction of iron could be determined. Furthermore, visible cracks were investigated with the goal to determine the long-term durability. It was shown that the data provided by micro-CT is reliable and helpful for the characterisation of industrial waste agglomerates. Keywords: X-ray, computed tomography, micro-CT, agglomerates, manganese fines, slags, kaolinite, bentonite

Jan 1, 2020

By I. Çinar

Cappadocia is not only a region of Turkey with historical and touristic importance. During the cutting and processing of volcanic tuff, quarries in this region release large amounts of tuff into the environment that is viewed as waste. The release of this waste constitutes an economic loss and contributes to environmental pollution. However, through experimentation with deformation, weight per unit of volume, water absorption, uniaxial compression strength, modulus of elasticity, and point load strength index, volcanic tuff and marble dust composite materials can be produced for use in the building sector. In this study it was observed that, as the percentage of volcanic tuff dust in the mixture increased, the water absorption rate of the material increased, and uniaxial compression strength and point load strength decreased. The produced composite samples used in this study were kept for a predetermined number of times per day, and no deformation in the surface characteristics of the materials was observed. In a statistical parameter analysis, averages, variances, standard deviations, coefficients of variation, and skewness coefficients were calculated. Covariance changes between experimental parameters were also determined. In this study, two types of volcanic tuff dust, that is, yellow and red, were produced during the production of tuff-marble dust composite material. When the percentage of either type of volcanic tuff dust was increased, an increase in water absorption was observed. It was also observed that when the percentage of volcanic tuff dust was increased, uniaxial compressive strength and point load strength decreased. Furthermore, the physical and mechanical properties of the materials obtained by mixing different colored tuff powders and marble powders in different proportions were evaluated using statistical parameter analysis.

Mar 5, 2025

By H Zimba, S Sondashi, M Chitambo

By the time a reagent is finally accepted by a mine for use on its plant it could have gone through several screening and evaluation stages. These stages may include laboratory and plant evaluation testwork. This paper outlines the steps that were followed to select, design and implement a frother for KONKOLA COPPER MINES PLC Nchanga Copper Concentrator in Zambia. It discusses initial frother screening work conducted at the Betachem metallurgical laboratory and the subsequent laboratory screening testwork conducted at Nchanga Concentrator. A modified Bikerman test method is discussed which was used to design a frother for the Nchanga flotation plant. The paper also gives an account of several plant scale trials conducted on Nchanga flotation plant and discusses the plant results, frother consumption patterns and some commercial concerns, before the product was finally accepted by the mine.

Jan 1, 2007

By H. Immink

Keywords: Kyoto Protocol, carbon credits, global warming, energy, auditing Climate change is nowadays being taken increasingly seriously, and the link between global warming and the carbon dioxide released in the generation of energy is coming under increasing scrutiny. The Kyoto Protocol was signed in 1997, after five years of negotiation. So far, about 84 countries have ratified this agreement, under which terms developed countries have strict targets linked to their 1990 level of emissions. However, ?greenhouse gas? (such as carbon dioxide) emissions continue to rise alarmingly. According to the World Resources Institute, greenhouse gas emissions in the USA increased 13% from 1990-2002, while Australia recorded a 22% increase. In contrast, the European Union, a Kyoto signatory, has seen a small decline in its emissions during the same period. This is led by the UK and Germany, who reduced their emissions by 15% and 19% respectively. The concept of ?carbon credits? provides a funding mechanism for companies in the developed world to compensate for some of their CO2 emissions by paying companies (trading credits) elsewhere in the world to undertake projects to bring about reductions in emissions. In the southern African mining industry, it will be possible to get refunded for undertaking voluntary emission-reduction projects. Concern about the environment is creating business opportunities. A preliminary calculation has shown that various projects in South Africa (those in the pipeline, with quite a high likelihood of coming off) could earn a combined total of about R2.5-billion, under the initial phase of the Kyoto Protocol&apos;s carbon-credit scheme, which allows developed-country companies to trade credits with developing countries. A number of local companies are planning projects that could comply with the Clean Development Mechanism (CDM), in which they will implement techniques to achieve certified emission reductions (CERs) of greenhouse gases. In order to prevent abuse of such a system involving vast sums of money, vigorous audits need to be carried out. A company has to prove it has made real changes and is not simply conducting business as usual under a cloak of claimed environmental improvements. PricewaterhouseCoopers has applied to become one of only a few international agencies that will be accredited to conduct validation and verification of the credits, by auditing what is called the ?designated operational entity?. An independent validator needs to confirm that the project meets the strict requirements of the Kyoto Protocol. The company has to demonstrate that it?s not business as usual. So, if you refurbished every five years, the next refurbishment is not a good CDM project, unless you can demonstrate that you will do something beyond the maintenance - that is what can be registered. So, Kyoto intends to get additional projects going, and the money for that is actually quite good - prices of 14 euros per ton of carbon dioxide not emitted have been seen. The price depends on who takes the risk for non-delivery if a project doesn?t deliver the emission reductions on time. The highly energy-intensive South African mining industry is heavily dependent on coal. There should be many opportunities for the pyrometallurgical industry to come up with creative ideas to reduce emissions, and there is now an additional financial incentive to encourage this. Companies can actually get money in return for doing these types of projects, in addition to the contribution to corporate social responsibility.

Jan 1, 2006

By S. Ganguly, R. Kononov

Carbothermal reduction of manganese oxides and manganese ores in the solid state was studied in hydrogen, helium and argon at different temperatures, ore compositions and carbon to manganese oxide ratios. Wesselsore (South Africa) and two grades of the Groote Eylandt ore (Australia) with different level of impurities were examined. Ores were characterised by XRD, X-ray fluorescence, optical microscopy and scanning electronmicroscopy. Isothermal and temperature programmed carbothermal reduction experiments were conducted in a fixed bed reactor in a vertical tube furnace, with on-line monitoring of gas composition by the CO-CO2 infrared sensor. The reduced samples were characterised by XRD, SEM and LECO analyses. Extent of reduction was calculated using data on the off-gas composition, and LECO carbon and oxygen contents in the reduced sample. Manganese oxides in the ore were reduced to a-Mn and carbides Mn23C6 and Mn7C3 depending on the carbon to ore ratio. The reduction rate of manganese ores in hydrogen was higher than in helium and argon. Key words: Manganese, Carbothermal Reduction, Hydrogen, Argon, Carbon Monoxide, Helium, Kinetics.

Jan 1, 2007

By M. Ksiazek

Keywords: Thermal conductivity, thermal diffusivity, flash method, specific heat capacity, manganese ore Manganese ferro-alloys manufacturing involves a combination of quality raw materials and an energy source to produce high-quality products with low energy consumption. The thermal properties of manganese raw materials such as ores, sinters, and briquettes, are among the many factors that determine the amount of energy needed for processing. Thermal expansion, thermal diffusivity, conductivity, and apparent specific heat capacity of solid samples and compacted powder samples of manganese ores were examined from room temperature to 1000 °C. The effect of porosity (of the materials used) on the thermal properties was also investigated. The laser flash method and a pushrod dilatometer were used.

Jan 1, 2011

By K. B. Le Bron, T. van Aard

The empirical pillar strength formulae have been widely, and in most cases successfully, applied to design underground pillars for mines in the Bushveld Igneous Complex (BIC). This paper presents the case for combining the empirical method with numerical modelling when it comes to crush pillar stability analyses. The benefits include an understanding of potential failure mechanisms, which may then be accounted for in the designs. In addition, the impact of weak layers, such as shear zones, the impact of the dip of the orebody, differences in layouts, such as holing widths and the presence of advanced strike gulleys (ASGs) immediately adjacent to the crush pillars, and stress regime (k-ratio) may be studied using numerical modelling, as it is not accounted for in the empirical method.

Mar 5, 2025

By J. -Y. Jia, G. -B. Qiu, C. -G. Bai, D. -F. Chen

Due to the great importance of the smelting process, it is essential to establish a calculation model on the viscosity of the slag system containing titania. In this paper, the calculation models of mass action concentrations and viscosity for the CaO-SiO2-TiO2slag system have been established according to the coexistence theory of the slag structure, as well as the referenced viscosities ofCaO-SiO2-TiO2at different temperatures and TiO2compositions. With the two models, corresponding calculated programs are made by means of programming language Matlab5.3, and the curves of viscosity of the TiO2concentration (?TiO2/%) at 1400°C, (R=0.9~1.0) are plotted. The results show that mass action concentrations of TiO2increases with increasing percentage ofTiO2, while the viscosity of CaO-SiO2-TiO2system is decreased. The results show that the models are in good agreement with the experimental and referenced data. They also shows that the models are reasonable for the CaO-SiO2-TiO2slag system. Keywords: coexistence theory; CaO-SiO2-TiO2slag system; viscosity ; calculation models.

Jan 1, 2004

By L. Schernikau, W. H. Smith

Oil, coal, and gas account for approximately 80% of global primary energy, but only a portion of total airborne CO2 eq (approx. 35% at GWP20 to 65% at GWP100), even though they account for 95% of total measured CO2 emissions. The benefits of these energy sources, as well as their related costs, are not all incorporated in current energy policy discussions. Global greenhouse gas policies must include documented changes in measured airborne CO2 eq to avoid spending large amounts of public funds on ineffective or sub-optimal policies. The authors examined airborne CO2, which is less than half of emitted CO2, as well as reported CH4 emissions and the global warming potential of CH4 as published by the IPCC for coal and natural gas. The surprising conclusion is that surfaced-mined coal appears ‘better for the climate’ than the average natural gas, and all coal appears beneficial over LNG. Therefore, current CO2-only reduction policies and CO2 taxes are leading to unintended consequences and the switch from coal to natural gas, especially LNG, will not have the desired impact of reducing predicted future global warming; in fact, quite the contrary. A large portion of anthropogenic global warming is attributed by the IPCC and IEA to CH4, but it must be noted that CH4 emissions from natural sources and from agriculture account for approximately 40% and 25% of annual global CH4 emissions respectively. Energy accounts for about 20% of documented CH4 emissions. CO2 contributes only approximately 35% of annual airborne anthropogenic GHG emissions after accounting for CH4, over a 20-year horizon. At a 100-year horizon, the contribution of CO2 increases to approximately 60%. Energy policies that do not consider all GHG emissions along the entire value chain will lead to undesired economic and environmental distortions. All carbon taxation and CO2 pricing schemes are incorrect and need to be revised. At IPCC’s GWP20 an approximately 2%1 higher loss of CH4 across the value chain prior to combustion of natural gas versus coal will lead to ‘climate parity’ of coal with natural gas. According to public data, natural gas value chains have high CH4 and undocumented CO2 losses. On a global average, using only IEA-documented CH4 data, natural gas emits approximately 15% more CO2 eq than surface-mined coal, over a 20-year horizon. This difference will increase as the use of shale gas and LNG expands. Investors should support all energy systems in a manner that avoids an energy crisis, including intermittent renewable energy systems where they make sense. If CO2 emissions need to be reduced, one of the most effective ways would be to install ultra-supercritical power plants with CCUS technology. However, the undisputed benefits of increased CO2 concentrations in the atmosphere because of its promotion of photosynthesis and plant growth effects (fertilization) need to be considered in energy policy decisions as well. The authors suggest that future research and development should concentrate on reducing net emissions from fossil fuel power plants and providing cost-effective and reliable new conventional power generation capacity, utilizing clean coal and clean natural gas technology.

Mar 2, 2022

By S. Sakurai, N. Shimizu

The stability of slopes is a crucial problem not only in open pit mines, but also in civil engineering situations. The deformational behaviour of slopes is in general monitored during/after the excavation by carrying out field measurements where displacement measurements are commonly adopted. In monitoring the slope stability it should be emphasized that the measurement results must be properly interpreted so as to assess whether the slopes are stable or become unstable in the future. In order to interpret the data, back analysis is extremely useful. In this paper a slope stability monitoring system is described. It consists of displacement measurements by GPS, and a back analysis of measured data. The use of GPS has a great advantage, because of the fact that continuous displacement measurements with high accuracy for a large extent of concerned area can be easily achieved. On the other hand, the back analysis can reveal the mechanical characteristics of the ground, which make it possible to assess the stability of slopes quantitatively.

Jan 1, 2006

By A. M. Garbers-Craig, T. Coetsee, T. M. Nemavhola

Accretions often form in furnaces when slag and charge materials attach to the refractory wall and build up over time. Accretion formation is usually unwanted because it reduces the working volume of the reactor and hinders material flow through the reactor. However, in some instances a thin, stable accretion layer may be desirable to protect the underlying refractory material. In order to prevent and/or manage accretion formation, it is important to understand the underlying principles of this phenomenon in the particular reactor. Excessive accretion formation hampered production at the Exxaro FerroAlloys ferrosilicon melting and atomization plant. This plant uses induction furnaces in which a 15% silicon-iron alloy is produced by batch smelting a mixture of ferrosilicon of 75%Si grade and low-carbon steel. The molten ferrosilicon alloy is then gas-atomized to a powdered product for use as a dense medium in mineral processing plants. The objective of this study was to investigate the effect of different impurity levels in the ferrosilicon feed material on the extent of accretion formation as well as the effect on the accretion properties, which influence the ease of accretion removal upon furnace shut-down. Refractory and accretion samples were collected after a furnace shut-down and characterized using X-ray diffraction and scanning electron microscopy–energy dispersive spectroscopy. It was concluded that the trace elements in the FeSi-75 feed material (Al, Ca, Mn) were mostly responsible for accretion formation, but that rust on the low-carbon steel and oxidation of the steel contributed to accretion attachment to the lining. The total contaminant content, calcium to aluminium ratio in the FeSi-75 feed material, and thereby the liquid to solids ratio in the accretion at temperature determine the strength of attachment as well as growth of the accretion.

Feb 2, 2021

By L. Holappa

Ferroalloy production is an energy-intensive industrial sector with significant CO2 emissions. In this paper the current situation in ferroalloy processes is discussed from the standpoint of global environmental issues, trends and development. Progress and data of ferroalloys production are frequently compared with the steel industry, which is a closely related sector and the main user of ferroalloys. Emission factors of processes and electricity production are examined as well as possibilities and future scenarios of how to diminish CO2 emissions. As a part of this study a questionnaire was submitted to experts in the field of ferroalloys worldwide to survey opinions on the ferroalloy industry today and in the near future (2020). Eighteen questions concerning raw materials, energy, environmental aspects, by-products and economic aspects were responded to by seventeen experts, the answers were analysed and conclusions were drawn. Keywords Ferroalloys, energy, CO2 emissions, electricity, sustainability, questionnaire.

Jan 1, 2010

By J. J. Taute, S. J. Archer

"BASF Mining Solutions has developed a new-generation copper solvent extraction reagent that offers significant benefits over standard extractants currently available to the industry. As the name suggests, the new hightemperature (HT) extractant can be used at a higher operating temperature, but also exhibits significantly lower degradation rates, greater copper-toiron selectivity, and is totally nitration-proof compared with the standard extractants. Pilot-plant trials have also shown that lower aqueous-inorganic entrainment can be achieved. This paper investigates the technoeconomic benefit of using the HT extractant as an alternative to the standard extractant in a high-temperature application. The results of the technical evaluation showed that the use of the HT extractant reduces the extractant addition requirements and bleed volume from copper electrowinning; this smaller bleed requirement further reduces acid and limestone consumption, leading to a reduction in valuable metal losses. The results of the economic evaluation showed that the use of the HT extractant represents significant cost savings over that of the standard extractant. IntroductionCurrent solvent extraction (SX) reagents employed for the extraction of copper from typical pregnant leach solutions (PLS) at ambient conditions function well with minimal long-term effects on the extractant’s performance (Taute et al., 2015). This performance, however, deteriorates at elevated temperatures due to the degradation of the reagent’s hydroxyoximes. The degradation mechanism, acid-catalysed hydrolysis of the oxime, is accelerated by high temperature. This has a knock-on effect where the increase in degradation products increases the organic viscosity, leading to increased entrainment, crud formation, and ultimately to an increase in SX reagent consumption (Bender, Emmerich, and Nisbett, 2013).SX reagents also show an increase in the co-extraction of iron as the ferric concentration in the PLS increases. Co-extracted iron is transferred to electrowinning (EW) during stripping of the loaded organic and can adversely affect EW current efficiency. Iron in the EW circuit is typically managed by bleeding the electrolyte; however, this can lead to excessive consumption of EW reagents such as acid, cobalt, and mist-eliminating surfactants. The electrolyte bleed can also affect upstream consumption of reagents, such as lime, due to the high acid concentration recycled to leach."

Nov 1, 2018

By S. F. Burks

"This paper develops themes explained at two SAIMM platinum conferences. Optimization techniques can be used to significantly increase the value of mining businesses by enabling better long-term planning decisions. Open pit and underground mine design, mine scheduling, cut-off grade and blending, stockpiling, and the linking of these to flexible elements of the metallurgical recovery processes are all evaluated together. Transport or sale of intermediate products and the requirements of the product metal markets can also be considered. Experience shows that net present value (NPV) can be increased significantly, usually even before the expenditure of significant amounts of project capital. Recent studies of NPV have aimed to simultaneously evaluate the impact of the optimized financial solution on the non-financial features of a project or operation.The case study presented comprised a commercially orientated review of the prefeasibility study designs and cost estimates of a platinum group metal (PGM) project in South Africa, followed by value chain optimization and sustainability studies of the project carried out simultaneously to identify potential value uplifts to be gained and guide the owners’ team going forward into the feasibility study phase. Some of the major aspects of the project that were found to have significant potential to add value included enhancement of the business model by the application of activitybased costing and theory of constraints, focus on the highest net value portions of the orebody in the early years of production, enhanced and optimized scheduling of the underground mining operation, application of dynamic grind and percentage mass recovery from ore to flotation concentrate (also known as percentage mass pull) to optimize revenue, application of elevated cut-off grades early in the life of mine, matching of the mining and processing capacity, expansion of the operation subject to capital availability, and installation of downstream processing facilities subject to regional third-party capacities.The investigation of non-financial project features focused on demonstrating that a financially optimized solution could also have a number of other benefits. These are mentioned briefly in the paper, which aims to present the status of the project at an early stage of its development."

Jan 1, 2016

By R. J. Hundermark, S. Sun

The oxidation state dependence of the electrical conductivity of a calcium ferrite slag with 25 wt% CaO was measured at 1300°C using a shallow slag layer and two-electrode technique. The experiments were started in air and the slag was sequentially reduced by means of a controlled gas atmosphere using CO2and CO. The electrical conductivity in air was approximately 300 S/m and increased with reduction to approximately 1900 S/m at a pO2of 10-10atm. The interest in the oxidation state dependence of the conductivity of calcium ferrite slags was to provide a comparison with the conductivity of iron silicate slags and to establish the effect of slag basicity on the electrical conductivity and its oxidation state dependence. The results obtained are discussed in terms of the slag structural information available in the literature. The co-ordination of the ferric ions appears to play a large role in determining the electrical conductivity. Keywords: calcium ferrite, slags, electrical conductivity.

Jan 1, 2004

By Q. P. Campbell

The high final total moisture content of fine coal after mining and processing is one of the major reasons that this resource is not extensively used in subsequent power generation, combustion, or other conversion processes. Some coal products, like export coal, may be subjected to a variety of environmental conditions during transport and storage, such as temperature and humidity. To understand the mechanisms by which moisture is attracted and held on and within fine coal particles, further information is needed regarding the processes occurring at the coal surface. In order to determine the correlation between physical coal properties and its moisture adsorption and desorption characteristics, a series of sorption experiments were conducted on various coal samples under climatically controlled conditions. Equilibrium moisture data was collected while changing the temperature and humidity. This data was correlated to coal properties such as particle size, porosity, maceral composition, and mineral content. All the coals that were studied were medium-rank bituminous coals. It was found that the best predictors for moisture adsorption and desorption were the mineral and inertinite contents. Keywords moisture, adsorption, desorption, fine coal, surface properties.

Nov 1, 2013

By O. I. Ostrovski, D. K. Belashchenko

The aim of this paper is the construction of models of systems with ionic and ionic-covalent bonds (molten salts) using experimental diffraction data and the calculation of their structure and thermodynamic and transport properties. Modelling was performed using algorithm BELION, in which the non-coulomb part of interaction potential between ions in the model was determined by the method of iterative simulation which targeted agreement between calculated and experimental partial pair correlation functions (PPCFs). The ionic charges in salts, which can be fractional, were determined by minimization of internal energy. In this paper, the algorithm BELION is applied for chlorides of alkaline-earth metals. Pair potentials, PPCFs, atomization energies, self-diffusion coefficients and electric conductivity are calculated. The charge of alkaline-earth metals was in the range of 2.0-2.1, slightly increasing from Mg to Ba. Partial pair correlation functions and atomization energies of models agree well with experimental data for MgCl2, SrCl2and BaCl2. Keywords: molten salt, molecular dynamics, partial pair correlation function, ionic charge, atomization energy, diffusion.

Jan 1, 2004

By P. O. Akinseye, F. T. Cawood

Mineral royalties are one of the oldest forms of mining taxation, and were initially introduced to extract economic rents from mining. Over time, the royalty regime has become more complex as it was identified as an important policy instrument that can achieve more multi-faceted outcomes. Such a multi-tiered approach in the use of the royalty instrument is also the case with South Africa. With South Africa’s new mineral royalty regime now in place for ten years, it is perhaps time to assess its impact and effectiveness. To carry out this assessment, an econometric evaluative study was undertaken using four major commodities in South Africa, namely gold, platinum, iron ore, and coal. The study explored five different policy options for government to consider and tested them to determine the most favourable one that will realize the regime’s policy objectives. After the assessment, two major options stood out. Hence, this paper seeks to highlight which of the two options is the most favourable for consideration by policymakers. Based on that study, we find that the current structure is effective, but also recommend that the factors in the formula for refined minerals be ‘modified’ to reduce the capped profitability ratio from the current 60% to 30% and the maximum royalty rate for refined minerals from 5% to 3%. The minimum rate of 0.5% during times of depressed mineral prices and no or low profitability will not be affected.

Dec 1, 2021