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By NIM REPORTS

Notices CONFRRENCE ON COMPUTRRS IN ENGINEERING The above Conference, which is being organized by the Electrical and Electronics Board of the Institution of Engineer!!, Australia, ill to be held in Sydney on 16th and 17th May, 1974. It is being planned in conjunction with the Sixth Australian Computer Conference and will be held during the week immediately preceding the latter. NIM REPORTS Report No. 1495 A method for the determination of ekmental sulphur on the surface of sulphide minerals. Report No. 1500 The chromatographic separation and determination of nobk metals in matte-leach residues. Report No. 1505 The production of the refractory aluminium saicates, with special refererence to South Africa. Report No. 1517 Computer-controlled flotation plants in Canada and Finland. Report No. 1526 Heat of solution as a control of aqueous-ammonia concentration. Report No. 1529 South African costs of equipment for the metallurgical industry (197).

Jan 9, 1973

By O. K. H. Sheff

An editorial in the April 1990 edition of Mining Magazine is worth a wider audience in South Africa, particularly as the SAIMM enters its own centenary decade and the process of change in the minerals industry world-wide makes increasing demands on the professionalism of its leaders. The editorial considers the changing status of engineers, who up to the 1880s had been held in high regard by society. Alumina and bauxite Economists forecast a slower economic growth rate in 1990, but expect continued increase in demand for aluminum at a 3 per cent annual rate during the decade. Structural and numerical analysis Struceng & Femcad (structural analysis and finiteelement method) is a conference and exhibition that is to be held in Grenoble (France) on 17th and 18th October, 1990. It is sponsored by the Institute for Industrial Technology Transfer (ITT-International).

Jan 1, 1990

By C. J. Lenz

The results of prospecting operations involving geological data and a large number of geochemical determinations of the metal content of soil samples are plotted and evaluated by computer. Anomalous areas are identified in each type of environment by selecting probability or population boundary values from frequency distributions. The anomalies are plotted to permit correlation with geographical or geological features. Ranking of prospecting targets is made using geographic pattern, geology, absolute value and metal ratios. Three short case histories are presented.

Jan 1, 2014

By A. W. S. Schumann

A. W. S. Schumann The first reason for todays success lies in the very high standard which was set by our speakers today and I think that we owe a very special vote of thanks to Messrs P. M. C. Wilson, A. A. Oakes, M. J. Deats, A. C. Coetzee, R. E. Burnton and J. G. Ferguson. This, however, cannot account for the fact that there was a tremendous response even before anyone knew who was going to speak or what they were going to speak about. I suggest that the response was enthusiastic because people expected a more informal gathering with a greater opportunity for feedback, for an exchange of views and for questions and answers. The very popularity of the idea has defeated its own ends to some extent. This gathering is too big and many people must have been left with questions unanswered. Possibly one should arrange for a number of meeting places-there are many in the Chamber and the surrounding mining houses-and then have separate meetings in the morning with joint reporting session in the afternoon. Alternatively, we could have a symposium after the colloquium, using Webster's definition of a symposium as as 'a drinking party of merry fellows'. We all know that it is easy to discuss mining into the small hours. Obviously one cannot summarise todays papers and discussions, but I would like to make a few comments on technical matters and after that I would like to speak for a moment about what I see as major trends or tendencies which arise from discussions of this nature. Regarding the question of placing a village on a mine or away from a mine, I would mention that there is quite a body of literature on the adverse sociological effects on the development of children in any community in which the great majority of parents share the same occupation. It is something to be avoided if possible. We discussed the concept of the moving stockpile. If this is proved to be successful, it could save a considerable amount of money for Escom who could then avoid the construction of very large and costly staithes which are now regarded as parts of power stations. One does not see why both a moving stockpile and a staith should be necessary. By the way, speaking of Escom, I see that Mr Bob Scott is here; he has stopped pulling my leg by saying that we sell stone to Escom; perhaps someone has told him that if this is true, it must be the cheapest stone you can buy in this country. My next point relates to the use of epidiascope. It struck me again that this instrument which provides a visual image to accompany your message, can be very effective if it is properly used. These papers speak of a great deal of hard work which went into their preparation, and one really feels that the authors should have taken a few minutes more to prepare their drawings specifically for the epidiascope. There should be nothing on the drawing which is not necessary to illustrate a particular point and there should be nothing on the drawing which is not visible from the back of the hall. In particular, if one cannot read the figures along the sides, then one

By D. W. Dean, J. A. Ryder

"A computer system designed to assist in maintenance scheduling and costing, and in monitoring the performance of equipment, is described. The emphasis is on the information retrieval and implementation aspects of the system.INTRODUCTIONThe cost of the maintenance of equipment can account for a substantial proportion of the total costs of any large industry. These costs are made up of the following elements:(i) capital expenditure,(ii) maintenance labour,(iii) maintenance spares,(iv) maintenance overheads,(v) production losses.Control of these cost elements cannot be achieved without a system which maintains and retrieves the necessary infor¬mation efficiently.The system should provide engineering management with the information necessary to:(i) establish the cost of maintaining items of equipment,(ii)establish the economic life of equipment,(iii) determine breakdown patterns for the establishment of optimum inspection, service and overhaul frequencies,(iv) establish work schedules for those responsible for the maintenance of equipment,(v) establish the optimum maintenance labour complement,(vi) establish the optimum stockholding of maintenance stores items,(vii) improve the performance of equipment,(viii) justify the selection of a particular type and make of equipment,(ix) establish the reasons for any abnormal usage of materials and labour, and to(x)reduce the dependence on the human element for the control of equipment maintenance activities.Many industries have comprehensive and numerous equipment maintenance records but they experience great difficulty in retrieving the required information in the time available and with the labour available. Many industries do not bother to maintain meaningful records, because of this difficulty."

Jan 1, 2014

By C. A. Green, M. A. T. Cocquerel, R. T. Gates

"Engineering studies by Selection Trust, Limited, initially in connection with the development of a copper and nickel deposit for Bamangwato Concessions, Limited, and subsequently for several other clients, have required a large number of metallurgical design calculations. The flash smelting process, developed by Outokumpu Oy in Finland, has been selected as the most suitable method for these projects and the computer programs described in this paper have been developed to facilitate the computation.The data required by the programs arc the chemical and mineralogical analyses of the concentrate, gangue and flux materials and the specification of possible fuels. The required grade of furnace matte is set as the main design parameter and the programs calculate detailed heat and material balances for the smelting process."

Jan 1, 2014

"Chairman: Professor J. de V. Lambrechts Rapporteur: Mr R. HempPapers:Computer-aided design of a flash smelting installation by M. A. T. Cocquerel, R. T. Gates and L. A. GreenPlanning of mine ventilation by E. U. Reuther and A. DohrnenCoal mine ventilation systems in the U.S.A. by R. Stefanko and R. V. Ramani Heat flow models in ventilation planning by A. J. Dickson and A. M. StarfieldThe first of the papers in the session dealt with a flash smelter installation, while the remaining three papers dealt with mine ventilation. In view of this the Chairman proposed that the paper on flash smelting be introduced and discussed first, after which the remaining three papers would be introduced followed by discussion on all three.Dr Cocquerel, who presented the first paper, used some typical flow diagrams to illustrate the process and stated that the program considered only steady-state operations and did not take into account the dynamical changes. Subjective judgment was necessary for the preparation of input data and some degree of user appreciation was required.Dr Cocquerel said that no work bad yet been done on an optimization program, but that this was being considered. Such a program would require a large amount of physical and chemical data which were not yet available. The variables to be optimized were the energy and material consumptions and the loss of metal in the slag.The Chairman opened the discussion by asking Dr Cocquerel if he could give a brief description of the flash smelting process for the benefit of those not familiar with the subject. Dr Coquerel replied that in the Outokumpu process con¬centrates were injected directly into the furnace, and that the process was somewhat analogous to flash distillation or evaporation processes, but was perhaps closer to the burning of pulverized fuel.The process had two distinct advantages. First, the heat evolved in the smelting reaction was used to heat the furnace, which resulted in less fuel consumption, and, second, the effluent gases were cheaper to treat than the effluent gases from other pyrometallurgical processes. This was important particularly in view of the current interest in pollution problems.Mr P. Marais thought that the authors had done themselves an injustice by not including details of the very complex processes taking place in the furnace."

Jan 1, 2014

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 R. Weber

Methane explosions in underground coal mines are a major concern across the mining industry. After the Pike River disaster, Arnot Coal became even more aware of the explosion risk. To determine whether Arnot has adequate precautions against a methane explosion, such as the one that led to the Pike River disaster, a literature survey covering the causes of the incident and what preventative measures should have been in place was conducted. Many different methane explosion prevention methods were evaluated, as well as codes of practice. Based on the findings, Arnot?s measures to prevent conditions favourable for a methane explosion were evaluated.

Jan 1, 2014

By H. Laitala, M. Lampi

Metso Outotec has developed a wide range of solvent-extraction technologies over decades and has introduced Metso Outotec VSF®X solvent-extraction plant. Standardized and modularized, Metso Outotec VSFX Plant provides a novel way to design, manufacture, transport, install, operate, and maintain solvent-extraction plants far better than in the past with highly sustainable and safe methods. For the customer, this means fast-track projects with savings in means of time, costs, quality, and operation. Sicomines and Metso Outotec have together implemented and commissioned a modern and efficient copper solvent-extraction plant. Plant commissioning and ramp up of the plant were fast and the plant is now operating efficiently. This paper presents Sicomines’ VSFX copper solvent-extraction project and gives a sight into operating figures for the plant.

Jan 1, 2023

By J. P. Garnier, T. Bhambhani, J. A. Garcia, N. Renaud

Most flotation plants use a static reagent scheme, i.e., a set combination of collectors, frothers, and modifiers. This scheme is usually developed and refined over time to deliver optimal (not necessarily the highest) performance when the major ore types are fed to the plant. However, when ore types or mineralogy coming to the plant change substantially (and this often happens as different areas of the pit(s) are mined and crushed at the same time), there are upsets in the process, typically leading to lower recoveries. Adapting to this variability is usually done only when performance drastically suffers, and the changes made may be too late and bring additional variability in performance. The premise for SmartFloat™ is that the reagent suite needs to be dynamic, adapting continuously to changes in the ore and operating conditions. Solvay has combined advanced analytics and data science techniques with its expertise in flotation reagent chemistry to systematically and automatically achieve the above, and in real time. Thus, SmartFloat™ is optimizing the reagent suite continuously, removing the additional variability created by belated human interactions resulting in a better and more stable process. In addition, this advanced approach allows for continuous improvement by identifying poor performing ore domains and improving the reagent suite using Solvay’s FM-100 approach to design appropriate solutions.

Jan 1, 2023

By M. R. Anderton

"A hierarchical four-character code designed for geological and allied data may be used to log exploration drill-holes and store the information on magnetic media. The code is intended for use in semi-free format and permits the collection of as much, or as little, data as the geologist may require for the purpose in hand. A method of data storage by variable length records is discussed.Information may be retrieved by means of a simple enquiry language. Optional output facilities could allow the retrieval of data in a form suitable for direct input to a contouring package. The enquiry parameters and interrogation program can thus provide the interface between the data bank and associated application systems."

Jan 1, 2014

By A. Brodt, I. Mezhibovsky

The traditional vertical transportation systems deliver both gangue and useful mineral. The extraction of the desired minerals requires the construction of mineral processing and waste management plants, driving production costs, and often creating a negative environmental impact. The proposed technology is an integration of mineral processing within the transportation system. The mined rock is crushed and then loaded into a vertical lifting system filled with heavy media, with an intermediate density between the mineral and the waste rock. Driven by gravity separation, the desired mineral floats to the earth's surface, while the waste sinks. Delivered minerals and sunk waste is extracted from the heavy media and is then regenerated to a dry state. The useful mineral should be suitable for further use, and the waste used for backfilling. Remained residues of the heavy media may be recycled and reused in the vertical transportation system. Trials of the proposed process in a pilot format have confirmed economic and environmental advantages over traditional methods of transportation and mineral processing technologies. Keywords: Gravitational processes of mineral processing, separation in heavy media, vertical transportation to earth's surface by floating up

Jan 1, 2020

By A. Mainza, I. Govender, Elbasher M. E. Ahmed

A mechanistic description of axial segregation in rotating drum flows remains an open question. Consequently, optimal mixing of grinding balls and rocks for efficient breakage, maximum production of fines, and slurry transport is seldom achieved. Experimental and numerical studies of granular mixtures in rotating drums identify alternating axial bands that eventually coarsen in the long-term limit. Most models of axial segregation are limited to binary mixtures and cannot always predict the logarithmic coarsening effects observed experimentally. A key missing factor is a robust description of the axial free surface profile that is valid across a wide range of flow regimes. We present a practical model of the axial free surface profile by linking it to readily-derived geometric features of the cross-sectional S-shaped free surface profile. A parametric study shows good agreement with experimental measurements reported in the literature and heuristically valid trends.

May 1, 2021

By C. B. van den Berg

n this study, silver and palladium nanoparticulate inks with different metal-binder ratios were screen-printed onto a paper substrate. The printed layers comprised the metal nanoparticles and an ethylcellulose binder. The layers are not typical metal composites due to the low concentration of binder and high porosity. The electrical sheet resistivity of each particle concentration was measured, and the data fitted using the scaling law of percolation theory and the general effective media (GEM) equation. The percolation parameters, i.e. the percolation threshold and the critical exponent, for each system were determined from the fits and compared. The percolation threshold for the palladium layer (39.8 wt%) was lower than that found for the silver layer (44.9 wt%). The critical exponents determined for the palladium and silver layers were both lower than the universal value for three-dimensional percolation systems. Microscopy observations indicate that the difference in the percolation threshold for the two layers can be attributed to variations in their microstructure.

Jan 1, 2014

By M. Saghaeian, R. Hejazi, L. Hosseini, M. V. Sheikhzadeh

HPGR equipment has been well proven to be energy-efficient in the first stage of grinding in iron ore beneficiation plants. Numerous advantages of utilising HPGR grinding prior to ball mill grinding, such as reducing the power consumption in a ball mill through generation of micro-cracks, has been thoroughly studied. Less attention has been paid to efficiency of the HPGR circuit rather than the downstream ball mill circuit. In this study the HPGR circuit has been optimised through feed size reduction by crushing, and feed iron content upgrading by dry cobbing. This optimisation leads to better operation of the HPGR, and a smaller product size which is expected to result in a lower wear rate of ball mill liners and balls. It is also expected that the top size of the ball mill balls be reduced. Additionally, by reducing the feed size of HPGR from 30 mm to 15 mm, it is possible to achieve similar K80 of HPGR product in lowered pressure, i.e. 2.5 N.mm-2 instead of 3.5 N.mm-2 which translates to ease of operation. Similarly in a given roll pressure, smaller feed sizes result in higher specific throughput of ~10% which means higher production capacities. The results also reveal that this optimisation increases the concentrate weight recovery by about 10%. It also results in slight increases in the Fe grade of the product iron concentrate. Keywords: HPGR, HPGR circuit optimisation, crushing prior to HPGR, dry cobbing prior to HPGR, ease of operation, concentrate grade optimisation, weight recovery optimisation

Jan 1, 2020

By L. S. Bicalho, W. J. Rodrigues, P. M. A. Rollo, P. R. G. Brandão, W. C. da Silva

Quadrilátero Ferrífero is an important mineral province located in Minas Gerais state, responsible for a substantial amount of iron production in Brazil. Among the concentration methods for iron ore practised by the mining companies in this region, the most important is the reverse cationic flotation. Dolomite iron formations, with the presence of hematite, quartz and dolomite, occur in several areas of mining and, with the deepening of the deposits, this type of ore, with low iron content and more complex mineralogy occurs frequently. Carbonaceous minerals, mainly dolomite, present a technological challenge for the concentration of iron ore by flotation. In the present study, the concentration of iron ore with 6% of dolomite content was evaluated. Bench flotation trials indicated that conventional iron ore flotation is not selective to float dolomite, thus compromising the iron content in the final concentrate. Alternative flotation routes were evaluated, and a selective condition was reached to float both quartz and dolomite using the combination of the cationic collector Flotigam 16424 with an anionic collector Flotinor 16551. It was demonstrated that the flotation of dolomite was improved with the combined use of both collectors in the cleaner stage, and by a previous quartz flotation in the rougher stage. Zeta potential analysis indicated specific adsorption as the adsorption mechanism between Flotinor 16551 and dolomite, confirming the high selectivity observed in the bench flotation tests. Keywords: Flotation, iron ore, dolomite

Jan 1, 2020

By R. o. Cretier, L. A. Cisternas, A. López-Valdivieso, F. Valdes, E. Gálvez, G. Gahona

The size of the particle plays an important role in the flotation of minerals. Comminution allows the release of valuable species and their subsequent recovery. Then, the degree of concentration and recovery will depend on the size of the particle. In this work, we investigated the flotation of coarse particles (-850 +150 μm) of copper ores when using the fluidized-bed separator (HydroFloat® cell) and compared it with the process of conventional flotation with medium size particle (-150 μm) (Metso cell) using seawater. The collector concentration was the main variable studied in terms of copper recovery. The results show that the flotation of coarse particles is feasible using seawater without frother

Jan 1, 2020

By J. -M. Milazzo, T. Wallmach, S. B. Blancher, A. Amalric

In a FeNi electric arc furnace, the physical properties of the slag (chemistry, viscosity, liquid/solid/gas ratio) are of crucial importance in controlling the efficiency of the process. In this paper, we studied the slag crystallised on the walls of a semi-industrial furnace (freeze-lining), the slag rising through the burden during foaming phenomena, and the casted slag. The freeze-lining is the layer of oxides that crystallises on the refractory wall of a furnace, protecting it from chemical and mechanical aggression. It records changes in furnace conditions (slag chemistry, temperature, oxygen fugacity), which makes it possible to observe the impact of these elements. In the high reduction test, the freezing lining is composed of magnesian olivine. Switching to a low reduction process increases the Fe content of the olivine and causes orthopyroxene to appear, making the freeze-lining mechanically and thermally weak. Thermal incidents in the furnace cause significant slag foaming. This foaming is produced by a massive crystallisation of the olivine (due to the drop in temperature), and inducing an exponential increase in viscosity, preventing the free circulation of gases. These foaming episodes are also recorded in the freeze lining and form layers rich in gas bubbles, and therefore mechanically fragile. The slag casted and cooled in a ladle allows the first steps of slag crystallisation to be studied. Olivine is the liquidus phase, with a magnesium-rich core and an iron-enriched rim, contemporaneous with the orthopyroxene phase. The habitus of these phases is very similar to that found in komatiites for the same minerals. FeNi slag is therefore an industrial analogue that is easy to study and compare to komatiites. Keywords: Pyrometallurgy, ferronickel, slag, freeze-lining, characterisation, olivine, mineralogy

Jan 1, 2020

By Q. Fu, Q. Wang, L. G. Wen, M. X. Jia, J. J. Zhao, J. W. Zhou

The BGRIMM process mineralogy analyser (BPMA) is a new automated mineralogy software platform developed in China. This system consists of the BPMA software platform, controlling a combination of commercially available scanning electron microscopy (SEM) and energy dispersive Xray spectrometry (EDS). The BPMA software controls SEM and EDS through their application programming interfaces, to form an auto-SEM and EDS system that automatically acquires BSE images and X-ray spectra, respectively, and classifies minerals by spectrum-matching. After automated measurement and mineral identification, various quantitative process mineralogical data (e.g., mineral composition, mineral abundance, mineral liberation and intergrowth relationships, mineral associations, particle and grain sizes, particle density distributions, calculated assay, elemental deportments, mineral grade recovery and elemental grade recovery, etc.) would be calculated quickly, accurately and automatically. The BPMA could be used for ore characterisation as a new advanced automated mineralogy technology. Keywords: BSE image; X-ray spectrum; automated mineral identification; quantitative mineralogical investigation; automated mineralogy

Jan 1, 2020