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By V. Jokovic

Hydrocyclones are the most commonly used classifiers in the mining industry. The reason for this is their low operating cost and a small footprint. Data from plant trials where screens replaced hydrocyclones indicated that lower bypass of fines and sharper separation could improve breakage rates, with a positive effect on flotation circuit performance throughput. Despite the importance of classification, hydrocyclones have not received as much attention as more expensive comminution units, and their technological progress has been incremental. Noticeable water split (Rf) reductions of a semi-inverted hydrocyclone have been reported in the past. According to theory, the hydrocyclone with reduced Rf will improve classification of fines. A classification study using semi-inverted hydrocyclones was conducted to determine if a hydrocyclone could be operated in a way that would minimise misclassified fines. The classification performance of a semi-inverted hydrocyclone will be presented in this paper and other potential applications will be discussed. Keywords: Semi-inverted hydrocyclone, water split, misclassification of fines

Jan 1, 2020

By G. Akdogan, J. H. Zietsman, C. Dorfling, D. Attah-Kyei

The development of newer and improved electrical products has led to an increase in the rate at which older products are discarded as waste. The main focus of electronic waste is the printed circuit board (PCB) because of the inherently high value of contained metals such as gold and copper. Several options for treatment of the non-metallic fraction including material recycling, where the residue may be used as inclusions in concrete or asphalt materials with minimal processing or chemical recycling, where chemicals and fuels are produced from the residue using pyrolysis exist. In this paper, the utilisation of the non-metallic leached PCB waste fraction as reductant in secondary copper smelting was investigated. Analysis of the leached residue revealed that PCB is highly amorphous and has a carbon content of 28.5%, an oxygen content of 23.1%, with the ash and volatile matter contents 40.1% and 44.8% respectively. Thermodynamic simulations of secondary smelting of copper were conducted in terms of metal recovery, and the energy required when PCB was used as a reductant. The results were also compared with that of coal and PCB-coal blends. The simulations revealed that as PCB in the blend used as reductants increases, the amount of energy required for the smelting operation decreases. Metal recovery slightly decreased as the mass percent of PCB in the blend increased due to lower carbon content present in PCB relative to coal. The results also highlighted the energy saving with PCB-coal blends which was around 160 kWh per ton of feed relative to coal. The decrease in the amount of energy required for the operation is attributed to the higher volatile content of the PCB, which is also a part of the reduction process. Keywords: PCB leach residue, alternative reducing agent, secondary copper smelting

Jan 1, 2020

By J. Zwartendyk, A. Azis

"Every nation must decide how it should exploit its mineral resources so as to contribute most to its national objectives. It is argued that the present value of the future corporate income tax flow derived from mineral exploitation may serve as a useful indicator in moving toward a taxation policy that would contribute optimally toward the greatest public benefit.The future stream of corporate income taxes depends largely on the mineral endowment, consisting of deposits now being mined, known unmined deposits, and unknown deposits.Unknown deposits may be estimated by geological inference. Both known and unknown deposits can be categorized according to grade and size, and divided into economic and uneconomic deposits on the basis of certain prices, costs, rate of return and taxation levels.Computer simulations can be run of discounted cash flow models at various taxation levels to show the impact of taxation changes on future tax revenues."

Jan 1, 2014

By W. Gabryk

A large new underground platinum mining project required that all different mining options were investigated during an option study before proceeding to the prefeasibility stage of the project. The capital project team identified 21 different options requiring investigation. These options considered 10 different access methods and 4 different mining methods. Each of the 21 options required a mine design, a valid production schedule, and the associated economics in order to facilitate a comparison on project Net Present Value (NPV) and other metrics. The project sponsors required this work to be completed in 3 months and therefore the project team decided to adopt an object-oriented modelling approach as implemented by Cyest Corporation. This would allow all 21 options to be valuated within the tight time frame due to the generation and re-use of templates. Standard objects were configured into templates containing the mine layout, design, and scheduling logic. These templates could then be assembled into a model to represent the option being investigated. The adoption of rules-based design and production scheduling then allowed for the rapid generation of a valid production schedule for each option with different iterations of varying production ramp-up and mining efficiency assumptions. The activity-based operating costs, labour, and capital were also linked to the standard templates such as a half level or barrel, which were then replicated to represent the overall mine structure for each option under consideration. Using this approach for each option, a full production schedule was produced per mining activity, the operating costs were calculated using activity-based costing, an infrastructure capital expenditure estimate was determined, the development capital requirements costed, and an overall NPV determined. This options study was completed in an unprecedented 10 weeks and a recommendation was put through to the Business to take three of the options to the next study phase.

Jan 1, 2012

By J. A. L. Napier

It has been established that significant time-dependent stope convergence may occur over time periods of hours and days in certain hard-rock gold and platinum mines. The source of this time-dependent behaviour appears to be associated with both pre-existing discontinuities and with mining-induced fractures that form near the stope face. These induced fractures may be associated with blasting processes and may also be formed in response to high stress concentrations in the unmined regions immediately ahead of the stope face. In shallower platinum mining operations, time-dependent behaviour is, however, observed to be much less marked unless some form of specific mining-induced fracturing occurs. One particular case of considerable interest is the time-dependent behaviour that is found to be associated with the formation and deployment of crush pillars. The purpose of the paper is to present a simple limit-equilibrium computational model of this behaviour that is sensitive to both the formation sequence and the size of planned crush pillars in a mine layout. This model provides a useful means to optimize the sizing of crush pillars, and at the same time may be used to identify potentially hazardous circumstances in which pillars may not crush in a stable manner.

Jan 1, 2012

By J. P. T. Kapusta

"The copper smelting industry faces increasingly stringent environmental regulations and must continue driving innovation to reduce energy usage in its production chain. With the coming of age of ‘bottom-blowing’ copper technologies in China over the last decade, much renewed attention has been brought to tuyere bath smelting for clean copper-making. Since bottom-blowing sonic injection was originally developed and implemented in steelmaking in the 1970s and lead smelting in the 1990s, the time seems appropriate to revisit the sonic injection concepts and dispel some myths. After reviewing the trends in the copper industry and providing a brief historical context of research and development related to sonic injection, the author presents a comparison of the main submerged tuyere bath smelting technologies, namely the Noranda Reactor (NR), the Teniente Converter (TC), and the Chinese Bottom-Blowing Smelting Furnace (SKS/BBS) for copper, and the Queneau-Schuhmann-Lurgi Reactor (QSL) for lead. The core of this article, however, consists of a brief description of the fundamental theories for sonic injection (jetting regime) and ‘sonic flow mapping’ to illustrate the relationship between the minimum tuyere back-pressure required to achieve sonic flow and the tuyere internal diameter. The article also offers a comparison between side- and bottom-blowing in jetting regime before concluding with the author’s vision of the new trend in submerged tuyere bath smelting. IntroductionIn the last decade, developments in the copper smelting industry have been driven by two key concepts: (1) increasing cleaner smelting capacity to meet the world’s growing copper demand, as illustrated in Figure 1, and (2) increasing process off-gas capture to comply with more stringent environmental regulations and abide by a corporate social responsibility ethic of a clean work environment (for smelter employees) and clean air (for families living around smelters). The copper smelting industry has also faced some major challenges in the last few decades, including (1) low treatment and refining charges (TC/RC or processing fees) impacting custom smelters, (2) lower concentrate quality and grades with higher levels of impurities (e.g. As and Hg), (3) higher processing and transportation costs due to the rising cost of energy, (4) restrictions in process intensification (tonnage oxygen usage) due to furnace integrity limits, and (5) scarcity of educated and trained personnel due to fewer metallurgists graduating from pyrometallurgical school programmes combined with a high retirement rate of skilled workers."

Nov 1, 2018

By C. Liu, G. Zhu, Y. Liao

"The effect of particle size on the flotation kinetics of a low-rank coal was compared using air bubbles and oily bubbles. Five kinetic models were applied to the data from the tests to derive the relationships between the flotation rate constant, the ultimate recovery, and the particle size fraction. The results show that oily bubble flotation (OBF) resulted in a lower ash content and higher combustible recovery than air bubble flotation (ABF), especially for the -125 ??m size fraction. It was found that the flotation of a low-rank coal in individual size fractions using air bubbles and oily bubbles can be best described by a first-order model with rectangular distribution of tendency to float and the classical first-order model respectively. OBF yielded higher ultimate combustible and ultimate ash recoveries. The flotation rate constants for OBF were higher in all the models except for the fully mixed reactor model. The ultimate recovery values and modified rate constants first increased and then decreased as the size fraction decreased. The trend of the flotation rate constants as a function of the size fraction was similar in all the models except for the fully mixed reactor model. IntroductionFroth flotation is a physical-chemical separation method that is widely used in coal beneficiation for the separation of fine coal particles from associated minerals in water slurries. Since the cumulative recovery of a component in the concentrate is proportional to flotation time, the flotation process can be considered as a time-rate recovery process (Emad, Mohammad, and Bahram, 2010). Therefore, the general mathematical flotation models that incorporate both a recovery and a rate function can describe flotation time recovery profiles.The kinetics of coal flotation, as a measure of coal recovery as a function of time, have been studied in detail by many researchers. Different kinetic models have been proposed and published in the literature. The order and the rate constant are strongly dependent on the flotation conditions, such as the particle size and size distribution, the bubble concentration, the reagent concentrations, and the operating parameters (Zhang et al., 2013). The particle size has been reported to affect the flotation kinetics to a great extent (Yoon, Luttrell, and Asmatulu, 2002; Ntengwe and Witika, 2011). Numerous researchers have studied the aspects of flotation kinetics while paying special attention to particle size (Meftuni and Ibrahim, 1997; Rubinstein and Samygin, 1998; Graeme, 2012). However, the effect of particle size on the flotation kinetics of a low-rank coal has been relatively little discussed."

Jan 1, 2017

By R. Asamoah, P. Forson, S. Xu, W. Skinner, M. Zanin

In most auriferous hydrothermal deposits, gold is preferentially associated with pyrite and arsenopyrite minerals, with higher economic gold values noted for the latter and arsenian pyrite minerals. In this paper, surface (Cryo-XPS) and solution (EDTA extraction) analysis were used to characterise pyrite and arsenopyrite minerals under different aqueous conditions involving electrokinetic study and collector interactions to better understand ways of improving the separation of pyrite and arsenopyrite. The evidence showed higher surface oxidation at solution pulp pH values in the range of 4-11 for arsenopyrite relative to pyrite. The observed highest ratio of pyrite to arsenopyrite selectivity was 1.7 at collector concentration of 50 g/t and decreased with an increase in collector concentration. Keywords: EDTA extractable iron, selectivity index, differential flotation, grade engineering

Jan 1, 2020

By I. Soto, E. Córdova, A. Anani

The new caving megaprojects that are planned to go into production in the next decade have scheduled horizontal developments at very high rates, which are difficult to achieve. Research has been conducted that seeks to model the construction times for underground developments to determine the feasibility of achieving the planned rates. However, these previous attempts do not consider all the operational aspects that make up the mine development cycle. Here, we present a discrete event simulation (DES) model that individualizes each unit operation of the development cycle to determine the construction rates that new projects will be able to attain. The developed model was applied to the New Mine Level (NML) of the El Teniente Division (DET). The results indicate that it would be impractical to achieve the advance rates scheduled in the original plans if the unit operations of the mine continue to be executed using the status quo. The metres developed after six years in the sections analysed can be significantly improved by changing the maintenance strategy for the equipment (457 metres increase), orepass availability (194 metres increase), and the initial planning sequence (1 598 metres increase). It is recommended that the mine implements a flexible maintenance strategy, defines a strategy to ensure and increase orepass availability to contractors, and makes use of current simulation tools for a more robust development sequence planning.

Oct 1, 2022

By E H. O Meyer, K van Dyk

Fine powders normally exhibit, to a more or lesser extent, some ability to participate in dust explosions. Zinc dust as used in the extractive metallurgy of zinc, is not known to be a reactive powder in the industry. No evidence could be found in the literature where zinc dust was involved in an explosion or explosive type event. On 3 May 2002 an explosive type incident occurred at Zincor in Springs, South Africa, which led to a fatal accident. Given the history of relative benign behaviour of zinc powders under conditions conducive to dust explosions, it was decided to share the information of this incident with industry in an effort to prevent similar incidents. Therefore, the purpose of this paper is to describe the incident that occurred at Zincor, discuss the major findings, report on corrective actions, as well as publish the results of subsequent tests that were performed to determine the conditions under which zinc powder exhibits explosive characteristics.

Jan 1, 2005

By P. C. Pistorius, M. P. Maphutha, J. D. Steenkamp

Advanced high-strength steels (AHSS) are sophisticated materials being developed by the steel industry to mitigate challenges related to the performance of motor vehicles. To meet the requirements of AHSS, the ferromanganese alloys (FeMn) utilized in the production of the steel are required to contain acceptable levels of unwanted impurities, i.e. P, S, N, H, and C. The focus of the current study was to investigate dephosphorization of ferromanganese to produce a low-P alloy that could be effectively utilized in the production of AHSS. The study involved conducting laboratory-scale testwork to study the efficiency of CaO-based slag systems to dephosphorize FeMn alloys. The addition of Na2O, CaF2, and BaO to MnO-CaO-SiO2 slag was considered. The test work was carried out in a 25 kW induction furnace at temperatures of 1350°C, 1400°C, and 1450°C. The P partition coefficient (Lp) remained small at <1, which is an indication that dephosphorization had not been achieved. The baseline slag, comprising 40%CaO-40%SiO2-20%MnO, reported higher Lp values. Addition of Na2O and CaF2 did not show any further benefit. Substituting half of the CaO by BaO, resulted in similar Lp values to those of the baseline slag under conditions of 1350°C and 1450°C at 30 minutes. In summary, based on the Lp values obtained, the conditions investigated with the CaO-based slags appeared to have been unfavourable for dephosphorization of FeMn alloys, as most of this impurity element remained in the alloy.

Sep 1, 2021

By A. F. Silva, J. M. G. Sotomayor, V. F. N. Torres

Geotechnical monitoring plays an important role in the detection of operational safety issues in the slopes of open pits. Currently, monitoring companies offer several solutions involving robust technologies that boast highly reliable data and the ability to control risky conditions. The monitoring data must be processed and analysed so as to allow the results to be used for several purposes, thereby providing information that can be used to manage operational actions and optimize mining plans or engineering projects. In this work we analysed monitoring data (pore pressure and displacement) and its correlation with the tension and displacement of the mass of an established failure slope calculated using the finite element method. To optimize the back-analysis, a Python language routine was developed using input data (point coordinates, parameter matrix, and critical section) to use software with the rock mass parameters (cohesion, friction angle, Young’s modulus, and Poisson’s ratio). For the back-analysis, the Mohr-Coulomb criterion was applied with the shear strength reduction technique to obtain the strength reduction factor. The results were consistent with both the measured displacements and the maximum deformation contours, revealing the possible failure mechanism, allowing the strength parameters to be calibrated according to the slope failure conditions, and providing information about the contribution of each variable (parameter) to the slope failure in the study area.

Oct 1, 2021

By S. Zhao, S. P. He, M. Y. Zhu, Y. Tao

"The effect of two refining slags (A: 1.0–1.8 CaO/Al2O3 ratio, 11–20 wt% SiO2; and B: 1.0–1.2 CaO/SiO2 ratio, 25–35 wt% Al2O3) on the inclusion morphology of a carbon structural steel (Q235B) was studied by controlling the balance between the steel and the refining slag at 1600ºC in a Si–Mo resistance laboratory furnace. The results showed that most of the inclusions in the molten steel balanced with slag A were formed by a lowmelting CaO–MgO–Al2O3–SiO2 system with a total oxygen content (T[O]) being fixed at 6–13 ppm. The inclusions in liquid steel balanced with the slag B were mostly formed by the CaO–MnO–Al2O3–SiO2 system, with T[O] controlled to 19–26 ppm. The overall size of the inclusions under balance conditions was higher in the steel reacted with the slag B than that reacted with slag A, with the latter showing more inclusions smaller than 3 um. In order to generate a large number of spherical CaO–MgO–Al2O3–SiO2 inclusions smaller than 3 ??m while decreasing the T[O] in the resulting steel, the composition of slag A should be used. This composition allowed improving the cleanliness of the slab, and is also advantageous for the castability of the molten steel. IntroductionThe sample used in this study was a typical carbon steel manufactured by CQ Steel. The galvanized, tinned, and plastic composite steel plates made of the original plates are used extensively for decorative panels, general dust pipes, drums, instrument cases, switchboxes, and train cars, among other uses. The target control composition is shown in Table I. The S and P contents are usually fixed during production below 0.020 and 0.025 wt%, respectively, with the aim of reducing longitudinal cracks on the slab surface."

Jan 1, 2017

By Marek Dworzanowski

Dense medium separation (DMS) is critical to the operation of coal and diamond beneficiation plants. It is also utilised in iron ore, manganese, chromite and andalusite beneficiation as well as pre-concentration for platinum-bearing UG2 ore. Gravity concentration plays an important role in the processing of diamonds, coal, gold, platinum, titanium minerals, zircon, chromite, iron ore and manganese. The DMS and Gravity Concentration operations and technology in South Africa conference will focus on the operation of DMS and Gravity Concentration circuits in the South African Mining Industry. The current status of the technologies and equipment employed will be presented as well as future developments. The conference was set up to showcase South African DMS and Gravity Concentration operations and provide a forum where operators, technology and equipment suppliers can engage in knowledge sharing. The papers cover a wide spectrum of topics, including descriptions of operations, optimisation projects, new capital projects, equipment applications, process monitoring and process selection. Most commodities and unit processes associated with DMS and Gravity Concentration are covered. The conference venue was selected to be the CSIR Convention Centre in Pretoria. The CSIR has contributed to DMS research in South Africa and it is located not far from many coal, diamond, gold, platinum and chrome mines that extensively utilise DMS and Gravity Concentration in their beneficiation plants. I believe that the papers and presentations submitted for this conference will provide a valuable future reference for DMS and Gravity Concentration, thus making the work of all the contributors to this conference highly rewarding and worthwhile.

Jan 1, 2006

By L Dyer, G. J. Wilkie, P. Walters, B Tadesse, L. Keeney

Grade Engineering® is a term trademarked by the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE) and includes five key levers for upgrading ores and rejecting waste prior to expensive downstream comminution and mineral processing. These five levers include natural deportment, induced deportment, bulk sorting, particle sorting and gravity separation. Over the past ten years, CRC ORE has progressed a range of technologies that exploit these levers from laboratory proof of concept through to large scale demonstration and validation. This paper details the work carried out by CRC ORE and Curtin University for assessing the amenability of an ore for its natural deportment and particle sorting attributes in an Integrated Screening and Particle Sorting (ISPS) Grade Engineering® process. ISPS is seen as a preferred method for Grade Engineering® as compared to individually operated unit operations as the benefits of each can be complementary. Furthermore, it is suggested that integrating the two levers has two important impacts: 1. Firstly, there is a risk that isolated particle sorting test results will be misinterpreted as being representative of the full sample without considering the mass balance impact of high-grade material that might have been lost in the fines fraction. This fine fraction will not be detected through the particle sorter. 2. Secondly, and potentially of more valuable impact, is that the opportunity may exist to upgrade the feed first through determining if there is a concentration of high grade to the fine (or coarse) fraction which can be separated through screening. Undertaking screening in the preparation stage of the particle sorting process will enable analysis and separation of the fine or coarse fractions of a rock mass. The result of this study provides the mining industry with an independent framework for undertaking an Order of Magnitude (ISPS) Grade Engineering® assessment on a range of constituent ore types. Keywords: Grade engineering, particle sorting, grade by size fractionation

Jan 1, 2020

Broken Hill Mines-1968, edited by M. Radmanovich and J. T. Woodcock, published by The Australian Institute of Mining and Metallurgy, Melbourne, 613 pages. Price $A15. This volume, containing some 65 technical papers, was produced for the 1968 annual conference of the Australasian Institute held at Broken Hill to mark the 75th Anniversary of that Institute, founded at Broken Hill in 1893. That conference also coincided with the 85th Anniversary of the discovery of the Broken Hill mining field. This closely reflects the position in this country, where the Witwatersrand gold fields were discovered in 1886, and our South African Institute of Mining and Metallurgy will in March, 1969 be celebrating the 75th Anniversary of the founding of the forerunners of our Institute. There is a comprehensive report of the geology of the Broken Hill area and the mineralogy of the ore body, and there are reports on the mining methods and the metallurgical procedures which have been developed over 85 years of operation of one of the great mining fields of the world. The value of most of the papers is enhanced by a large number of illustrations and photographs. An early section covers the academic and practical aspects of rock mechanics, prospecting, and exploration techniques are described in some detail. A third of the volume is devoted to mining, with papers on 26 aspects. The breadth of the coverage gives an indication of much specialized development, research, and consequent maturity in all departments. The detailed treatment of metallurgical aspects such as sizings of individual mineral particles throughout the milling stages and the development of an on-stream analysis system for lead will commend this volume to the specialist. The committee responsible for the production of this volume, which brings together much information previously only to be found after searching through numerous publications, are to be congratulated on a well produced comprehensive review of many aspects of the mining and metallurgical fields. H.B.

By T.R. Stacey

Physical testing of rock support for rockbursting conditions has been carried out for over 40 years. A review of this testing shows that it has been mostly component based, rather than actually testing support systems. Further, it is concluded that none of the testing is truly representative of rockburst loading in a similitude sense. Similitude conditions are not achievable, mainly because the real conditions in a rockburst event, such as seismic source location and magnitude, wave frequencies, amplitudes, and interactions, are not all known. Because such information is not available, and because the results of all testing carried out to date have not been able to define, for support design purposes, the capacity of support systems, ongoing physical testing of rockburst support systems is essential. It is essential that the test should simulate, or actually take place in, a supported rock excavation. A rock support system is a combination of individual support components that work together to retain and contain the rock. In doing this, the components are subjected to loading by the rock and to interactive loading between one component and another. It is necessary to prove the capacity of such rockburst support systems by subjecting them to severe loading, as in direct blasting. The direct blasting approach, pioneered more than 40 years ago, probably still provides the greatest validity as a significant test of rockburst support capabilities, even though it does not simulate a rockburst. Direct blast testing of rockburst support systems in a surface environment, such as in a quarry or on exposed rock cutting surfaces, could represent a practical development of the approach, facilitating the execution and monitoring of tests.

Jan 1, 2012

By A. J. Jager, D. P. Roberts

The stoping of platinum orebodies in the Bushveld has in the past been accomplished by using in-stope pillars to ensure stability of the workings. In the future, the use of continuous mining machines to mine the platinum orebodies is probable. It is not envisaged that such machines will cut in-stope pillars. This paper describes the alternative support systems that will replace the pillars and the stope geometries that will be required for this type of mining. The paper describes how the support resistance provided by in-stope pillars in current mining was determined and then evaluates support systems that can substitute for these pillars. Conceptual layouts based on existing breast mining layouts are presented. The layouts consist of panels of up to 100 m face length between rigid strike stabilizing pillars. A number of design charts are then proposed that allow for the design of appropriate support systems.

Jan 1, 2004

By L. Marais

The development of a post-mining economy is generally framed as accessible and desirable and something that mining companies, consultants, and the government can, and should, plan for. It is indeed possible. Yet, most mining regions, other than the big metropolitan municipalities, find economic diversification after mining challenging, despite their grand plans, consultant reports, and company intentions. Their efforts blind them to other ideas that are often prerequisites to diversification. This paper highlights some economic and social misconceptions about economic diversification and explains where planning goes wrong. Mistakes typically stem from ignorance and misunderstandings. Planners and policy makers fail to grasp the essential requirements for economic diversification. They underestimate the structural constraints created by mining. They do not see how mine rehabilitation is linked to economic diversification. They generally do not understand the South African space economy or the nature of new economies. The paper also proposes a more careful consideration of those economic aspects that mining cities have control over, such as land use management and infrastructure. The paper further explains how understanding long-term dependencies can help prevent governance failures. The social disruption that accompanies mine decline and closure must be recognised and dealt with. The mines must plan for decline as a way to resuscitate the economy. It concludes with a framework for assessing and developing a post-mining economy.

Apr 25, 2025

By K. Richardson

Although the De Beers group has a long history of placer mining on land, the group only became actively involved in deep water marine diamond exploration and mining in1983 with the formation of De Beers Marine. Full-scale commercial mining commenced around 1991. Since then, the group marine mining capability has grown into a formidable fleet of 8 large deep water (>70 m) mining vessels, as well as other special purpose geo-survey platforms. Marine diamond production by the group is expected to be just short of 1 million carats in 2006. DeBeers operates across the entire value-chain spectrum from geology and geo-survey, through sampling to mining, and finally ore processing into high value concentrate. Supporting these operations involves significant service activities such as maintenance, security, logistics and environmental management. Specific challenges exist in terms of developing or acquiring appropriate technology for marine mining. These challenges have resulted in DeBeers operating extensive in-house R&D and projects departments, as well as drawing extensively from technology partners. An array of computational and test facilities are also available to support R&D and projects activities. Hydro transport in various guises is key to the current approaches to marine mining and ore processing. Use is made of airlift and centrifugal pumping for hydraulic hoisting of very coarse gravel, while splitters, launders, dewatering, elutriators, jet-pumps, centrifugal pumps, dense medium circuits, pipeline systems, and instrumentation for coarse abrasive particles are used extensively in the ore processing plant.

Jan 1, 2007