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By Nobuzwe Makhotla, Sasha Boskovic, Steve Hearn

"Mineral separation efficiency in flotation depends, to an extent, on the type of frother used. Huntsman develops and manufactures unique frothers which are suited for mineral processing applications. This paper discusses the Huntsman approach to understanding the industry’s flotation frother requirements to optimise frother selection and introduce the Huntsman’s POLYFROTH® frother range. Specific case studies where the frothers are used are discussed. INTRODUCTION Froth flotation is a process of using bubbles to separate minerals based on their relative affinity for water. Bubbles are induced in the slurry through aeration. Chemistry is used to aid the flotation process and chemical reagents are added to enhance the separation process. The flotation reagents include frothers, collectors, surface modifiers and pH regulators that control physical and chemical conditions of solid, air and liquid phases, respectively. As described by Harris (1976), the key effect is that of bubble size control by way of preservation of the generated bubble size, which is attributed to the coalescence inhibition by the presence of the frother on the bubble surface. Following this, the frother must stabilize the froth phase. Frothers are also added to create optimal conditions for bubble creation and stability by decreasing the surface tension of the water. Depressants may be added, depending on the ore treated, to assist the hydrophilic particles to stay in the water phase. Clay particles may need to be dispersed to prevent them from attaching to the bubbles. Hydrophobic particles attach to the bubbles and are carried to the surface of the slurry where froth is formed. It is important for these bubbles to have the mobility to carry the mineral to the launder where the concentrate is collected. Types of Frothers There are generally three main groups of frothers used in froth flotation. Alcohol Type These frothers have a molecular structure that usually includes 5 to 8 carbon atoms in a hydrocarbon chain and their solubility in water is limited. Methyl isobutyl carbinol (MIBC) belongs to this category and is widely used in the industry. The weaker alcohol-type frothers are more selective and typically suited to finer particles. There are three sub-categories under this group: aliphatic, cyclic and aromatic alcohols."

Jan 1, 2015

By M. Machikicho, N. R. Shoko, J. Chirasha

Keywords: Pyrometallurgy, furnace, ferrochromium, alloys, Zimbabwe Zimbabwe Alloys was founded in 1949 by a consortium led by the John Brown Group. It was the first ferrochrome plant in Africa. The establishment of the refinery was necessitated by an increase in world stainless steel demand and the need to reduce cost by shipping alloy rather than chrome ore. The location of the refinery in Gweru was influenced by a number of factors, not least of which were the abundance of chrome ore deposits, access to inexpensive power from Kariba, the availability of reductant coke from Hwange, accessibility to ports (as the town was well served with rail and road networks second to none in the country), and of course cheaper labour costs. The production of Low Carbon Ferrochrome (LCFeCr) was commissioned in 1953 and produced from an Open Arc Furnace with a Submerged Arc Furnace producing Ferrosilicon Chrome (FeSiCr) that is used as a reductant in the production of LCFeCr. An experimental furnace was commissioned in 1958 to help with efficiency and control on larger furnaces. A second Submerged Furnace was commissioned in 1963. Three other Submerged Arc Furnaces were built between 1967 and 1974. Several mines were acquired between 1974 and 1984, as a strategic move to ensure the growth of the refinery. A briquetting plant was commissioned in 1977, enabling the use of friable ores to enhance the capacity of ore supplies and ore cost management. A plant to recover alloy from slag was established in 1994 to capitalize on market demand without large capital outlay that would be required to build other furnaces to increase capacity. Zimbabwe Alloys has created employment opportunities throughout the years. There have been direct employment opportunities at both the refinery and the mining divisions. With time, indirect employment was realised both upstream and downstream of the refining process, enhancing the livelihood of numerous people. Zimbabwe Alloys' involvement with various labour skills has, of necessity, enabled it to develop a culture of safety at work, home, and play. Zimbabwe Alloys has contributed to society by participating and funding various local initiatives primarily to impact positively on societal needs. The latest development was in 1996, when Zimbabwe Alloys entered into a Technical Transfer Agreement with Japan Metals and Chemicals to improve the efficiencies and hence the profitability of the LCFeCr production process. A significant quantity of various alloys has been produced since inception, and significant foreign currency has been earned for the country. This was in spite of challenges that included the cyclic nature of market prices, the upheavals of sanctions affecting the macro-economic environment, and the challenges related to the deteriorating grade of chrome ore and reductant coke.

Jan 1, 2006

By A. C. du Preez

Mintek has been involved in extensive test work since the early 1990s on the recovery of nickel and cobalt from leach liquors saturated in calcium, using synergistic solvent extraction systems. During this period the Nicksyn? reagent was developed, optimized, commercially manufactured, and tested by Tati Nickel on a demonstration plant for more than 2800 operating hours. Efficient recovery of nickel without the co-extraction of calcium, thus avoiding gypsum formation in the extraction and stripping circuits, was illustrated. This synergistic system was recently evaluated on a laboratory scale for the recovery of nickel and cobalt from synthetic lateritic sulphate leach liquor containing about 3 g/L nickel, 0.5 g/L cobalt, 0.7 g/L manganese, 20 g/L magnesium, and with calcium at saturation. Extraction and stripping parameters were determined for this feed liquor and are discussed in this paper.

Jan 1, 2014

By L. Kühnel, H. Lieberwirth

Confined bed comminution in High Pressure Grinding Rollers (HPGR) and Vertical Roller Mills (VRM) is gaining substantial attention in many applications. Previously used mainly for milling coal or construction materials, HPGR and VRM have started to complement or even replace tumbling mills in ore beneficiation. Materials like coal or clinker are relatively homogenous, however, in comparison to metal ores and wall rocks. This characteristic poses a new challenge to the confined bed comminution but also an opportunity. Fuerstenau and Abouzeid have investigated the selectivity in comminution of a mixture of particles of different strength in a particle bed. The median particle size and particle size distribution (PSD) of the two constituents used were kept constant. Only the proportion of the two constituents was modified. The competence of a material is, however, also a function of particle size. Smaller particles tend to be more competent than larger ones of the same material. If selective comminution is applied on ores, this size influence has to be understood. The paper presents research results on this topic based on experimental investigations with model materials as well as with natural particles, which were stressed in a piston-die press. It appeared that the comminution result depends substantially on the material characteristics and the composition of the mixture. Conclusions will be drawn for the application in future applications of selective comminution in mineral processing. Keywords: Confined bed comminution, HPGR, VRM, piston die press, particle size

Jan 1, 2020

By J. Muller

Keywords: Pyrometallurgy, blast furnace, slag viscosity, slag liquidus temperature, phase equilibria The viscosity of molten slag in blast furnace operations is an important process variable, influencing the rate and location of reactions inside the furnace, as well as the ease with which the final slag could be removed from the furnace. To optimize these processes, it is necessary to estimate the slag viscosity and liquidus temperatures as accurately as possible, and know the target values. Models to predict viscosities and liquidus temperatures, incorporating phase equilibrium calculations, have been developed and validated with measured data. Various diagrams have been developed to illustrate how the properties vary with composition and temperature, including pseudo-ternary diagrams of SiO2-MgO-CaO-Al2O3 for viscosity and liquidus temperature. Models were also applied and methodologies developed to analyse historical blast furnace operations and determine target values.

Jan 1, 2011

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 L. K. Witika, J. H. Masinja

"Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. Of the six frothers tested, two came from the alcohol family, two from the glycol family and last two were formulated products. The initial work involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. For froth stability tests, six frothers were tested on a two-phase (water–air) system using the Bikerman column flotation cell, while water recovery tests were conducted using a total of seven frothers, including the standards for each plant. The results of the testwork showed that (i) although a stable froth is essential for optimum recovery of valuable minerals, a higher molecular weight frother, like Dowfroth 250, caused poor selectivity when used on fine ores and (ii) a lower molecular weight frother was suited for Lumwana ore, while a mid to higher molecular weight formulated product was suitable for Kansanshi sulphide ore. INTRODUCTION Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. The initial work of this project involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. In order to investigate the gangue entrainment levels in the Lumwana and Kansanshi sulphide ores, two well-known methods (froth stability and water recovery) were used. Firstly, froth stability tests were conducted using six frothers, two from the glycol family (Dowfroth 200 and Dowfroth 250), two from alcohol family (MIBC and pine oil) and other two from the formulated family (Betafroth 20 and Betafroth 245), at the University of Cape Town’s Centre for Mineral Research (CMR) laboratories. Froth formation and stability measurements were conducted using the Bikerman column flotation cell."

Jan 1, 2015

By T. Ertekin, X. Dong

This paper identifies the need for the development of specialized inverse solution techniques for the analysis of pressure transient data for the characterization of the transport and sorption properties of coal seams. Central to the proposed inverse solution technique is a specially structured artificial neural network (ANN). The most important transport and sorption characteristics of coal seams are butt and face cleat permeabilities, macropore porosity, Langmuir volume constant, Langmuir pressure constant, and sorption time constant. Conventional methods, such as type curve matching techniques and laboratory-derived measurements are handicapped in terms of being representative over the entire domain of interest. In this paper, we utilize analytical forward solution techniques for various combinations of characteristics of coal seams to generate training and testing patterns. These training patterns are shown to an ANN structured to learn the ubiquitous non-linear relationships that exist between coal seam properties, input conditions and the pressure transients measured. The trained networks are then extensively tested to ensure that they have effectively learned the training patterns. In the final stage of the development, the networks are run in the prediction mode. The responses of the networks are found to be in agreement with the input data. The developed networks are able to generate results generally within 5% error margin for permeability and porosity and 20% error margin for the sorption characteristics of coal seams. A number of examples highlighting the capabilities and degree of effectiveness of the network in characterizing the coal seams areincluded. Keywords: artificial neural networks (ANNs); coal seam characteristics; pressure transient analysis

Jan 1, 2003

By J. A. Caldwell, G. E. Blight

The metropolitan area of the Witwatersrand has grown up around the Witwatersrand gold mines. Most of the mines have now been abandoned, but deposits of waste material remain and have been surrounded, and in some instances covered, by urban and industrial sprawl. This paper describes the development of geotechnical measures for the abatement of air and water pollution from abandoned gold-residue dams in the Witwatersrand area. The measures include the stabilization of the surfaces of the dams to prevent wind and water erosion, the terracing of slopes to minimize erosion, and the construction of catchment walls and dams. The measures were developed in terms of the set of guidelines for environmental protection adopted by the Chamber of Mines of South Africa in 1979.

Jan 1, 1983

By R. P. King

"A model of the flotation process can be used effectively for design and control. For design purposes it can be used to predict the performance of a large plant from laboratory and pilot plant data. It can be used for control purposes to assess the utility of any proposed operating modification to an existing plant, and it can also be used to determine optimal control settings for best operating performance.A model has been developed that will allow for variations in feed properties and for variations in fineness of grind. The model can be used to assess the effects of reagent addition rate, aeration rate and pulp level on plant performance and these are the control variables that are used individually or together in all operating flotation plants. The model provides for a distribution in the values for flotation rate constants, particle size and mineral fraction, and, because of its complexity, requires a large computer when it is to be applied to a typical plant configuration. The computational method that is used to apply this model to such configurations is described in this paper, and particular attention is paid to the problem of allowing for feedback of tailings from cleaners and recleaners."

Jan 1, 2014

By M. Jacobs

Keywords: Smelting, converting, sulphide, sulphide smelting, platinum, platinum group metals, PGM, base metals, nickel, copper, matte, slag, furnace, electric furnace, Söderberg, electrode, granulation, converter, flash drier, sulphuric acid, acid plant, Ausmelt, Sirosmelt, pyrometallurgy, metallurgy, Anglo Platinum, South Africa Waterval Smelter complex is situated in Rustenburg, in South Africa?s North West Province. The smelter objective is to process wet concentrate to produce crushed, slow-cooled, sulphur-deficient nickel-copper matte rich in platinum group metals (PGMs), gold, and base metals for despatch to the Magnetic Concentration Plant at the Base Metals Refinery. Throughout its history, the smelter complex has been continuously upgraded in line with increasing production demand, changing feeds, environmental initiatives, and advances in available technology. The smelter receives filter cake and slurry from Anglo Platinum concentrators and joint ventures. Wet concentrate is fed through a flash drying process utilising coal-fired, fluidised bed hot-gas generators, to produce dry feed material for the electric furnaces and slag-cleaning furnace. For primary smelting, two electric furnaces are used, each with a rated capacity of 34MW. Furnace matte, containing the bulk of the base metal sulphides and PGMs, is tapped periodically into refractory-lined ladles and granulated using high-pressure water jets, then dried through electrically powered pneumo-driers to become the main feed to the Anglo platinum Converting Process (ACP). Slag is tapped semi-continuously, granulated, and treated through the slag mill. The ACP treats the combined matte output of Waterval, Polokwane, and Mortimer smelters. It is a top-blown furnace, with furnace matte, air, and oxygen being injected into the converter via a lance submerged in the slag. Converter matte is tapped and bottom cast into moulds, slow-cooled, crushed, and despatched to the refineries. Slag is granulated and dried for recycling to the slag-cleaning furnace. ACP slag is fed to the slag-cleaning furnace along with a reductant and a sulphur source. Slag-cleaning-furnace matte is granulated for processing by the ACP, while slag is granulated and processed in the slag mill. The slag mill and flotation circuit treats granulated slag from the electric furnaces and slag-cleaning furnace to recover entrained matte containing valuable PGMs and base metal sulphides.

Jan 1, 2006

By L. Aspola

The platinum group metals (PGMs), i.e. ruthenium, rhodium, palladium, osmium, iridium, and platinum, are typically found in association with each other, but also importantly, with nickel and copper. Typically Platinum and palladium have the greatest economic significance and other PGMs are typically produced as co-products of these. With recent increases in the value of nickel, cobalt, and the PGMs and an ever increasing focus on the sustainable use of metals, interest in the processing of secondary feed material sources and metal-bearing residues has also substantially increased. As an efficient, proven, and environmentally sound technology Outotec Ausmelt Top Submerged Lance (TSL) Technology has gained commercial acceptance in the nickel industry, including PGM recovery. For the processing of nickel- and PGM-bearing feed materials, five Outotec Ausmelt Furnaces at four sites are in operation. Two of these furnaces are located in Rustenburg, South Africa, which is by far the biggest mine-based producer of platinum. Outotec also has hydrometallurgical processes available for further treatment and extraction of PGMs, which are also briefly discussed.

Jan 1, 2012

By W. Dziurzynski, S. Nawrat, A. Krach

The paper presents research on the influence of the goaf methane inflow on a fire. The problem was investigated by a computer simulation of a fire developing in a goaf. A relevant mathematical model of the fire was selected, which considered both burning of coal and methane. The combustion process is very sensitive on the oxygen and methane concentrations, which was indicated on graphs of the fire temperature evolution. Examples of computer simulation for various location of the fire were considerd. Analysys of results confirms the influence of the content of the goaf methane on development of fires.

Jan 1, 2003

By D. Norval

Keywords: Pyrometallurgy, slag, metal, entrained, granulation, ferromanganese Water granulation of certain slags with high metal entrainment has customarily not been practised, not only due to the belief that such processes are too dangerous and unproven in the pyrometallurgical industry, but also that it might not be economically viable or environmentally acceptable. General slag granulation, on the other hand, is extensively applied, although in some cases crudely, with disastrous effects, as a result of not recognising the high heat capacities prevalent in slags. Thus, purpose-designed granulation and solidification processes are discussed, taking into account specific applications and the individual signatures of alloys and slags, emphasising that no slag, matte, or alloy responds in similar fashion to a granulation practice. This paper addresses three issues, namely: ? Water-granulation of BOF steel slag, without processing it to render it environmentally safe, physically and chemically acceptable for use by the construction industry, and the process economical ? Processing air-cooled BOF steel slag to change its physical and chemical properties to be acceptable for various uses and extracting metallic and bound iron ? Processing air-cooled or molten manganese slag to lower its manganese content to a level that is acceptable from an environmental and health point of view, and extracting FeMn-alloy of acceptable composition. The latter process culminated in a patented process to extract FeMn from air-cooled and molten manganese slag, and, at the same time, produce a hydraulic (cementitious) slag, thus transforming a possible hazardous by-product into virtually 100% saleable products.

Jan 1, 2011

By A. Aitio

Sustainable development is one of the central themes of the work of the World Health Organization; chemical safety is one of its important components. For more than 25 years, WHO has had specialized units for assisting member countries in dealing with their problems in chemical safety. For one of the units involved, International Programme on Chemical Safety, a reorientation is in progress to make best use of existing resources, and to prioritise the work to optimally correspond to the needs of the member countries. The risk assessment work of IPCS, and specifically, the work on chromium and chromium compounds, are discussed.

Jan 1, 2004

By T. C. Alex, K. M. Godiwalla, R. K. Jana

Manganese nodule, available in ocean beds, is a potential resource of the future for copper, nickel and cobalt. Recovering only these metals, containing less than 3% by weight, will result in the generation of large amount of residue. In addition to the material losses, several environmental and ecological problems arise out of this. The present study has been aimed at reducing the environmental and ecological problems associated with massive generation of this residue together with utilization of the resources. Presence of ~ 20% manganese and ~16% silicon in the residue has prompted us to check its suitability as a raw material for silicomanganese production. Lower manganese content and lower Mn/Fe ratio of the residue than that required for silicomanganese production has been corrected in this study by suitable blending. The efficacy of blending and its thermodynamic aspects using FACTSAGE software are discussed. The studies conducted indicate viability of bulk utilisation of the residue through silicomanganese production and thereby reducing the burden on environment to a great extent.

Jan 1, 2007

By J. van Zyl, K. B. Le Bron, L. J. Gardner

Pillar design is a crucial aspect of underground mining engineering, as it directly impacts the safety, stability, and overall effectiveness of mining operations. In this paper we present a method to calculate pillar stability based on the strain criterion and pillar load inversion concept, which complements the empirical pillar strength formulae. Those formulae do not account for certain parameters that can affect the stability of the pillars, e.g. weak layers, changes in stress orientations due to mining, orebody dip, mining layout complexity, and the influence of regional stabilizing pillars. The approach presented here is not intended to replace the empirical method; rather, we suggest using it as the initial step in the pillar design process. This should be followed by iterative numerical modelling to study pillar behaviour, define pillar stability, and optimize the pillar design by considering site-specific and representative rock mass properties and criteria.

Jun 10, 2024

By M. Shapiro, L. A. le Grange, B. Henning

Effective pyrometallurgical process vessel design requires accurate assessment of the heat fluxes through the walls of the furnace. This is particularly important for freeze lining operation which is designed to protect refractory materials exposed to chemically corrosive molten contents, or facilitate high temperature operation when the refractory materials are used at conditions close to their service limits. Numerical modelling of fluid flow and heat transfer in process vessels is often used to aid in the design of process vessels. Sophisticated models are used to analyse the three dimensional flow and heat transfer predicting the effects of electrical heating, magnetic stirring, buoyancy, shear forces, various cooling effects and ultimately heat fluxes at the walls of the furnace and refractory. Traditionally these models are applied to the separate single fluid systems in a vessel such as the freeboard region including the arc, the slag region and the metal bath. Boundary conditions such as shear forces and heat fluxes between connecting regions such as the slag and metal bath are either estimated or carried over from separate solutions. Shortcomings in these traditional approaches include the estimation of sometimes critical boundary conditions leading to unreliable heat flux calculations. Also when boundary conditions are carried over between solutions, the process is difficult to set up, time-consuming and finally not fully coupled. In this paper the definition and results of a fully integrated numerical model of a complete arc furnace are presented. The most important mechanisms acting in an arc furnace were considered, including the fields of electrical potential, current, magnetism, momentum, heat transfer and radiation. Temperature dependant properties included electrical conductivity, density, viscosity, and thermal conductivity. The geometry consists of the freeboard, the arc, slag, metal baths and different refractory regions. Although the combined model of air, slag and metal would be defined as a multi-phase problem it is not solved as such. Instead the different fluids are separated by sets of special solid baffles. These baffles allow the implicit transfer of current, magnetism, heat transfer and shear forces between the different fluids and disallow mixing of the separate fluids. The strengths of the integrated model are threefold: Firstly, it provides robustness in defining the geometry and boundary conditions for the overall model. Secondly, it provides the capability to switch on and off individual mechanisms such as buoyancy, magnetic stirring and shear forces in order to observe their individual importance. Finally, it provides a useful tool in the design process through its ability to obtain results of parameter changes in short time scales.

Jan 1, 2004

By D. F. Malan, U. Du Preez, P. S. Heyns

South Africa has two main platinum reef deposits, namely the Merensky reef and the UG2 reef. These reefs are currently mined using traditional drilling and blasting methods. Mechanized cutting could potentially enable continuous mining, which would offer significant advantages. This would require thorough understanding of the cutability of the rock. To explore this, a linear cutting machine was developed to conduct laboratory scale cutting tests. This work describes the development and commissioning of the cutting machine using sandstone, as well as subsequent characterization tests on UG2 reef samples. UG2 reef has large variability in strength on a millimeter scale. This introduces uncertainty in the test results due to added variance from one cut to the next for the same UG2 reef sample. Another problem is the variability in rock properties of the UG2 reef, when testing samples from different mines. The cutting tests led to fine fragmentation, which is known to be a significant problem for cleaning operations in underground stopes and warrants further research. A finite element method simulation of the rock cutting was conducted using ANSYS LS-DYNA and the continuous surface cap model to simulate rock cutting in the UG2 reef. It was found that it is possible to use LS-DYNA with the continuous surface cap model to model rock cutting of UG2 reef and get acceptable results, but the user must calibrate the model parameters using the experimental results. Therefore, the model is only fit for one set of cutting parameters and further work is required to generalize results.

Nov 27, 2024

By K. P. Davey

In 1998 an initial objective was given to the author, to process valuable off grade High Carbon Ferro Manganese (FeMn) metal fines profitably. The previous attempts that had been made to re-melt these metal fines through the furnaces had resulted in poor furnace operation, mainly to do with lack of electrode penetration and furnace bed permeability. It was decided that the method to resolve these problems was to agglomerate the metal fines. During the study on the agglomeration of the metal fines, a decision was made to use furnace baghouse dust and stockpiled furnace baghouse dust and sludge (DSF) as a ?filler? in the metal fines. The primary reason for using baghouse dust was to eliminate an environmental hazard, whereas the secondary reason for using the DSF was to utilize manganese units contained in the dust. The off-grade metal fines and dust were compacted using a brick press, with cement and aluminum rich plastic clay as a binder, to obtain agglomerate that was cost effective. Through the re-melting of the agglomerated off-grade metal fines, it was realized that this agglomerate concept could have other uses, that of replacing ores on the furnace, at a lower cost. The agglomerate recipe was changed to create an agglomerate that had a high manganese to iron ratio, this replaced Comilog ore on the furnaces, thereby reducing overall furnace unit costs. Future work concerning agglomeration, is to reduce furnace costs further through agglomerating .0.5mm ultra ore fines and .0.3mm Gloria and Nchwaning sludge. Using this agglomerate replaces a portion of the Gloria and Nchwaning lumpy ore on the furnaces at a lower cost. This would eliminate problematic material that exists at the ASSMANG Manganese mines.

Jan 1, 2004