Search Documents

By J. Botha

There are many underground mining software tools available to plan and schedule the development of underground mines. A shortfall of these tools is the optimization of the underground equipment and strategy in order to maximize the development rate. This paper will illustrate how the SimMine® software was used to maximize underground development at Petra Diamonds' Cullinan Diamond Mine. It will also determine the effect of various development strategies and equipment capacities on the underground development rate and pinpoint potential bottlenecks in the mine development cycle.

Jan 1, 2010

By D. Das, B. K. Nandi

The present study focuses on utilising the electrocoagulation (EC) process for the treatment of process water generated in an iron ore beneficiation plant for safe discharge and reuse. Removal of heavy metals like Fe, Cr, Cu, Zn, Mn and Pb which was found in higher concentration along with some other impurities exceeding the permissible and discharge limit were attempted. The influence of different electrode material, current density, inter-electrode distance, and solution conductivity was explored for effective removal of the metal ions. Experimental results infer that almost 99.95% Fe, 97.77% Cr, 73.44% Cu, 99.34% Pb and 88.69% Mn was removed using aluminum electrodes at monopolar mode at a current density of 68.50 A/m2, inter-electrode distance of 1 cm and solution conductivity of 1.033mS after 60 min of EC. In addition, removal of other toxins like TDS, turbidity, salinity and conductivity etc. was also assessed during the process. Removal of such heavy metal ions by EC was found to follow 1st order kinetics with electric energy consumption of 3.93 kWh/m3, electrode consumption of 0.1191 kg/m3 and operating cost of 0.6115 US$/m3 respectively. Keywords: Fe removal, electrocoagulation, Al electrode, turbidity

Jan 1, 2020

By J. Petersen, T. Moyo, J. Dinga

The leaching of chalcopyrite in ferric sulfate media is notorious for its slow and inhibited kinetics. Different methods have been proposed to improve the kinetics, including the use of organic compounds as additives to the leaching media. In this study, the enhancing effect of methanol, ethanol, 1-propanol, and 2-propanol on the leaching of chalcopyrite in aerated acid ferric sulfate solutions using different reactor systems was investigated. The results revealed a clear improvement of copper dissolution by methanol and 1-propanol relative to tests with no additives under similar conditions. Operating a continuous-flow mini-column reactor yields surprisingly good results, potentially related to the maintaining of a consistent leaching micro-environment on the mineral surface. Scanning electron microscopy studies showed that the alcohols result in the removal of surface deposits formed during the anodic dissolution, potentially thus facilitating improved cathodic reduction of the ferric ion to drive the anodic dissolution.

Jan 1, 2023

By H. Han, Z. Gao, Y. Gao, W. Sun, J. Wang

Strategic Ca-bearing minerals like scheelite and fluorite are usually separated by flotation, yet the separation is quite difficult due to their similar surface Ca active sites. Compared with the conventional strong collector sodium oleate (NaOL), lead nitrate-benzohydroxamic acid (Pb-BHA), complex collector shows a better selectivity for scheelite, yet its high cost hinders its wide application. Therefore, a novel collector (Pb-BHA-NaOL complex) was initially developed in this work to overcome the abovementioned dilemma. The flotation results of a single mineral showed that Pb-BHA-NaOL had a better selectivity for scheelite than Pb-BHA. Under the conditions of sequential assembly of Pb, BHA and NaOL at the molar ratio of 240:120:1 and pH 9.0, selective separation of scheelite from fluorite could be achieved without adding any depressants. In addition, for the same preferred scheelite recovery, Pb- BHA-NaOL could also save approximately 20% Pb and BHA compared with Pb-BHA. The analyses of the zeta potential measurement and X-ray photoelectron spectroscopy indicated that Pb-BHA-NaOL showed stronger adsorption on scheelite relative to fluorite. Meanwhile, Pb-BHA-NaOL showed more adsorption modes and higher utilisation of Pb and BHA on scheelite than Pb-BHA, which was due to the accelerator, NaOL. Keywords: Scheelite, fluorite, lead nitrate, benzohydroxamic acid, sodium oleate, flotation

Jan 1, 2020

By J. Mulenshi, J. Rosenkranz, P. Khavari, S. C. Chelgani

The geometallurgical concept has mainly been applied to primary ore deposits, starting from ore characterisation to the economic optimisation of the mining operation. However, as primary ore resources are becoming depleted and lower in grade, alternative sources need to be explored and a question of adaptability of the geometallurgical approach to the secondary resource repositories arises. The particle size distribution, chemical and mineralogical compositions of the Smaltjärnen historical tungsten tailings from physical separation in Yxsjöberg, Sweden were studied using drill core samples collected from different locations within the tailings repository in order to assess the amenability of the tailings to reprocessing. The tailings are dominated by the –600 to +149 μm particle size fraction. This fraction contains most of the elements of interest (W, Cu, S, Sn, Zn, Be, Bi and F) hosted by scheelite, chalcopyrite, pyrrhotite, cassiterite, danalite (both Zn and Be), bismuthinite and fluorite, respectively. The particle size distribution and mineralogical composition vary across the repository, suggesting a possible existence of geometallurgical domains, which require further assessment to evaluate metallurgical performance. Keywords: Historical tailings, tungsten, scheelite, geometallurgy, characterisation, mineralogy, reprocessing

Jan 1, 2020

By S. Shi, X. Xia, F. Xuesai, Z. Shen, D. Han

The hydrodynamic characteristics of a mechanical flotation cell’s transportation zone have significant impact on its metallurgical performance, especially on coarse particles recovery efficiency. However, how to define and adjust the transportation zone was seldom investigated by researchers. In this paper a method will be introduced to define the boundary of the transportation zone by PIV measurement. It is found that the transportation zone can be extended upwards by enlarging the entire rotor-stator assembly from the bottom of tank and increasing the jet angle of the impeller. Two control methods have been validated in industry tests on KYF-160m3 and KYF-320m3 air-forced mechanical flotation cells. The result shows coarse particles recovery are both improved distinctly. It is suggested that enlarging the top transport boundary is able to helpful to reduce the floating distance of bubbleparticle aggregates, which contribute to improve coarse particle recovery in large flotation cells. Key Words: Flotation cell; Transportation zone; Coarse particles flotation

Jan 1, 2020

The addition of binder to full plant tailings significantly affects the rheology of a backfill mixture and, consequently, the pressure gradients in the pipeline. The binder increases the yield stress and apparent viscosity of the mixture, and the transition velocity between the laminar and turbulent flow regimes. In a test conducted at a slurry relative density of 1,72 with binder addition, the mixture also exhibited time-dependent behaviour owing to the hydration of the binder.

Jan 1, 1993

By John Freer

A colloquium on solid-liquid separation was held by The South African Institute of Mining and Metallurgy on 23rd September, 1982, at the State Pavilion Auditorium, Milner Park, Johannesburg, to co-incide with the Electra Mining Exhibition. It was attended by about 150 delegates. Eight papers were presented covering: Geostatistics The School of Earth Sciences of Stanford University, the Centre de Geostatistique ofthe Paris School of Mines, and the Department de Genie Mineral of the Ecole Polytechnique of Montreal are cosponsoring the organization of a 2nd NATO ASI (North Atlantic Treaty Organization Advanced Study Institute), under the name of 'GEOSTAT TAHOE 1983', to be held at South Lake Tahoe, California, on 4th to 17th September, 1983.

Jan 1, 1982

By G. W. Healy

The smelting of calcium carbide has always been plagued by eruptions, too often with serious injury y or loss of life. To find their causes, the author calculated an internal energy balance using 1992 data for CaC2 and CaO, and older data for the remaining items. The heat content of the charge, and that of the hot gases formed at the reduction temperature, showed that only a fraction of its heat content can be supplied by these gases. Laboratory data on the electrical resistivity of fine mixtures of coke and non-conductive solids were extrapolated to a commercial carbide charge, and then used to calculate the heat produced by current flowing through the mix from the electrode surface to the hearth, which, under favourable conditions, sufficed to bring the charge to 1900 K and higher, at which temperatures reduction could take place.

Jan 1, 1995

By G. R. Addie, A. S. Roudnev

The Hydraulic Institute has completed the task of developing a new ANSI/HI standard 12.1-12.6 (2005) for rotodynamic (centrifugal) slurry pumps covering nomenclature, definitions, applications, and operation. The standard provides examples of the different slurry pump types and contains an extensive section on pump and slurry definitions. The effect of slurry on pump performance is covered along with the pumping of froth. Reference is also made to ANSI/HI standard 9.6.7 (2004), which contains anew method for pump performance correction when handling viscous fluids. Classification of slurry services is established and then is used to determine limitations on velocities and total head per pump in order to obtain acceptable wear performance. The new service class, head per stage and other limits are directly related to capital and other cost considerations that will affect solids transport system economics. The writers review the contents of the new standard, highlight the main points, and discuss the reason for the slurry classification, corresponding limits and expected implications, particularly with respect to operating costs of the pumps in solids transport systems.

Jan 1, 2007

By J. E. Gebhardt, B. Temel Mckenna, W. Lee, C. S. Macomber

X-ray diffraction (XRD) data was extracted from various sources to develop qualitative ternary and tetrahedral plots differentiating mineralogy, bond work index (BWi) and hardness of ore bodies at different mine sites. A large number of historic reports and compiled characterization laboratory data were used to create a searchable "data lake." The data lake provides a means to locate, consolidate, and visually represent XRD from disparate sources. Visualizations with large amounts of mineral ore XRD characterization data provide a qualitative assessment of ore properties, including comminution qualities such as material hardness. The visual map can be employed to quickly estimate expected ore character and behavior, given XRD analysis of samples from newly characterized and unfamiliar ore. Keywords: Mineralogy, Characterization, Comminution, Database, Ternary, Tetrahedral

Jan 1, 2020

By D. Mesa, J. Karvonenb, A. López, P. R. Brito-Parada, R. Grau, D. Davoise

The froth zone in flotation cells plays an important role in determining metallurgical performance. This is even more critical as cell sizes increase, since larger bursting surface areas can easily result in poor froth transport and even stagnant froth zones, which are detrimental to recovery. Generating additional overflowing lip length by adding internal launders and reducing surface area (while also directing the froth to the overflow) by adding crowders are well established design strategies to enhance froth mobility. However, comparative experimental studies of froth zone design modifications at industrial scale are scarce and often lack detailed froth characterisation. In this work, we present the results of two experimental campaigns that were carried out at Atalaya’s Riotinto concentrator in order to determine the effect of a new froth zone design on the flotation performance of a TankCell® e300 cell that operates as the first cell of the rougher bank. These campaigns provided a unique opportunity to assess froth phase phenomena and metallurgical performance before and after changes in design. The original cell design had an internal peripherical launder and a froth cone, while the new concentrate launder technology adds a centre launder and an adjustable froth crowder to the existing launder design. The new concentrate launder arrangement reduces significantly the froth area as well as the froth transport requirements, aiming to improve froth recovery and, consequently, enhance flotation performance, allowing copper recoveries in the TankCell® e300 cell to increase dramatically. In addition, radial profiles of froth height and froth velocity at the surface were determined, which provide valuable insight into the effect of design changes on froth stability and mobility. Keywords: Flotation performance, enhanced recovery, launder, crowder, froth stability

Jan 1, 2020

By Y. Tanaka, H. Miki, Y. Aoki, H. Okamoto, G. P. W. Suyantar, T. Hirajima

Due to environmental limitations and the scarcity of freshwater, flotation using seawater or desalinated seawater as process water becomes more common for mining operations. On the other hand, seawater has been reported to affect the flotation behavior of sulfide minerals. Few reports are available on influence of pyrite depression, recycled seawater and lime consumption on flotation by using seawater. In this study, the flotation tests were performed using ore sample to investigate the effect of pH with seawater and process water used in plant on the flotation behavior in a laboratory-scale flotation cell and a pilot plant-scale. The results of laboratory scale flotation indicated that copper and molybdenum flotation kinetics decreased with increasing pH. Furthermore, the iron (mainly pyrite) recovery decreased with increasing pH. The pilot plant-scale flotation test showed that water with a higher concentration of magnesium and calcium (plant processes water) consumed a higher amount of lime. Because of low lime consumption and high copper and molybdenum recovery and grade, pH 8 is suitable compared with pH 8.5 for flotation. Keywords: seawater, process water, copper-molybdenum rougher flotation, pH, pilot test

Jan 1, 2020

Four engineering products and three consumer products have received awards in the 1978 Shell Design Awards competition organized by the Design Institute of the South African Bureau of Standards. Norman Hanson Visiting Fellowship The Norman Hanson Visiting Fellowship, supported jointly by the National Development Fund for the Building Industry (inaugurated by the Building Industries Federation (8.A.)), the Institute of S.A. Architects, the Association of S.A. Quantity Surveyors, and the National Building Research Institute of the CSIR exists to finance fully or wholly visits by eminent authorities from overseas to South Africa for the purposes of seminars, informed discussions, consultation, and possible active participation in scientific, technological, and development projects of importance to the building industry.

Jan 1, 1979

For the Gold Fields Foundation National Engineering Awards, each university affiliated to the South African Federation of University Engineering Students (S.A.F.U.E.S.) selected a candidate who, in their opinion, presented the most outstanding design project in their final year during 1984. New President On 29th March, 1985, Mr B.C. (Bertie) Oberholzer, Manager of East Driefontein Gold Mine, was elected President of the Association of Mine Managers of South Africa for the ensuing year. Bullion from old film A pollution-free chemical method of producing silver that is 99 per cent pure-and therefore of bullion quality-from scrap photographic film and paper has been developed by a British company.

Jan 1, 1985

By J. Hadjigeorgiou, G. Knox

There is a considerable wealth of information on the behaviour of rockbolts under axial loading conditions both in situ and under controlled laboratory conditions. However, there is comparably less data on the behaviour of rockbolts in shear. Several authors have contributed to the understanding of the behaviour of conventional rockbolts’ performance under shear loading. Much of this data have been gathered through experimental programmes conducted on sections of the rockbolt. Considering the continuous coupling between the rockbolt and borehole interface, the approach is justified. Due to the design premise of energy-absorbing rockbolts with discrete couplings, full scale testing is required to quantify the behaviour of the rockbolts. This paper reviews published results obtained from two testing facilities, which are the SINTEF rockbolt pull test rig in Trondheim, Norway and the Epiroc Combinations Shear and Tensile test rig in Johannesburg, South Africa, both capable of conducting full scale testing of rockbolts. Based on this high-quality database it was possible to identify three distinct responses of rockbolts in shear. The behaviour under load is controlled by the presence or absence of an encapsulation medium (resin/cement grout), the reinforcement mechanism, and whether the rockbolt is continuously or discretely captured. As a reference the results are compared to the performance in shear of conventional grouted rockbolts.

Nov 24, 2025

By M. Saghaeian, R. Hejazi, V. Sheikhzadeha, A. H. Baladastian, A. Dehghani Ahmadabadi

This paper describes research done to remove apatite (phosphorus) from hematite ultrafine (70% finer than 25 micron) concentrate, recovered by electromagnetic separators at the FST Tailing Recovery Plant located in Chadormalu Iron Ore Complex through reverse froth flotation. As a result, iron and phosphorus content in magnetic concentrate (flotation feed) were 53.52% and 0.58%, respectively. Therefore, to increase the Fe content and decrease the P content of the sample, reverse flotation tests were applied. Chemical reagents used in this research consisted of sodium silicate as a depressant, sodium hydroxide and sodium carbonate as pH regulators, Alke & Dirol as fatty acid collectors and MIBC as frother. Process parameters including dosages of collectors, depressant and frother, preparation times of depressant and collectors, steps and time of frothing and pH range were selected. After doing flotation tests, in optimum condition, dosages of collectors were 1200 g/t, depressant 1200 g/t, pH in the range of 9.5 to 10, preparation time of collectors in the first step was eight minutes and at the other steps, four minutes; the number of frothing steps 4 and frothing time in each stage was three minutes. In this case, it was observed that the amount of phosphorus in the final concentrate was reduced to 0.05%, the Fe content increased from 53.52% to 61.66% and the Fe recovery achieved was 82.21%. Keywords: Iron ore, hematite ultrafine concentrate, iron and phosphorus content

Jan 1, 2020

By H. Möller, L. Mashigo, C. Gassmann

Wire-arc additive manufacturing (WAAM) is a directed-energy deposition technology that uses arc welding procedures to produce computer-aided designed parts, such as three-dimensional printed metal components. A challenge of additive manufacturing is the anisotropy. Interstitial elements play a significant role in the mechanical properties of Ti6Al4V of different grades. In this research, the mechanical properties of Grade 5 and Grade 23 Ti6Al4V were compared for this application. Samples were extracted from WAAM-produced Ti6Al4V walls in different directions (horizontal and vertical) and at different positions (top and bottom). The samples were subjected to optical microscopy and tensile and hardness tests. Grade 5 Ti6Al4V samples were found to have greater strength, greater hardness, and lower ductility, owing to the higher content of interstitial elements compared with Grade 23. The bottom samples had higher strength than the top samples, which is attributed to thermal cycling during manufacturing, resulting in different microstructures.

Jul 1, 2021

By P. Minkkinen, R. C. A. Minnitt

Particle size distribution analysis is important to many industries for assessing product quality, process efficiency, and compliance with contractual standards, while ensuring sample accuracy, and representativeness. Inaccurate particle size distribution results, arising from fines due to excessive handling can lead to penalties and buyer-seller disputes. A non-representative particle size distribution means samples will not accurately represent the chemical components either. Sampling blasthole cuttings poses challenges due to large material volumes, segregation, and uneven settling of particles in dense gold bearing ores. Commonly used sampling methods, such as spear or sectoral sampling, may lack representativeness. Particle size distribution analysis is crucial for evaluating sampling methods by comparing test sample representativeness against a reference standard derived from multiple particle size distribution analyses. Acceptable samples must fall within the 97.5% confidence intervals of the standard; deviations analyses lying outside these boundaries indicate a strong likelihood of segregation errors. A case study demonstrates this approach by using a 6.005 kg benchmark sample to assess two additional samples (1 kg and 5 kg), highlighting particle size distribution’s role in detecting sampling errors and refining protocols. An example of three test samples collected from reverse circulation drill cuttings compared to a standard reference sample is presented to illustrate a quality assurance/quality control procedure for reverse circulation drilling.

Oct 2, 2025

By I. Silin, H. Wotruba, A. Liono, I. Volobayev, Y. Rubinstein, D. Gürsel

Old, abandoned or in situ processed and storaged tailings can be a potential source of remained valuable metals and minerals. By reprocessing of tailings, it is possible not only to achieve economical profit from recovery of valuable metals, but also to reduce environmental damage caused by tailings such as generation of acid mine drainage from sulfide minerals, mobilization of heavy metals, soils and groundwater contamination. In addition, storage facilities can be successfully redesigned with modern geotechnical requirements and monitoring to avoid a dam collapse of abandoned tailings. In this case study, the processing of low grade abandoned tailings was investigated. Copper (0.15%), cobalt (0.032%) and gold (0.35 ppm) were determined as main valuable and recoverable metals. Cobalt occurs as cobaltite and cobaltiferrous pyrite, while chalcopyrite represents copper. The fine fraction of tailings below 32 μm is enriched with cobalt and copper. Preliminary test-works with initial tailings sample were aimed to recover copper, cobalt and gold. The previously tested magnetic and gravity separation could not recover the metals in a pre-concentration step. Flotation tests of the tailings sample had shown a suitability for flotation without previous regrinding of the tailings. The valuable minerals are first proposed to be recovered by collective flotation, followed by a selective circuit with production of a low grade copper concentrate and a cobalt bearing pyrite concentrate. Based on various tested collectors, amounts of sulfidisation agents and activators, a suitable reagents regime was determined and used for up-scaling by locked cycled test. Keywords: reprocessing, tailings, copper, cobalt, gold, flotation, cobaltite, cobaltiferrous pyrite

Jan 1, 2020