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By H. Hu, T. S. Golosinski

The paper reports on use of neural network algorithms to model performance and condition of mining trucks. The model inputs are selected digital data streams collected by truck Vital Information Management System, VIMS, during its operation in a mine. The models built as the result of this work allow for projection of truck condition and performance into future. As such they facilitate more efficient management of mine truck fleets. Keywords: Modelling, modeling, neural networks, mining equipment, Vital Information Management System, Intelligent Miner, mining truck

Jan 1, 2003

By R. L. Setsepu, S. O. Bada, J. Abdulsalam

The utilization of biomass as a solid fuel for co-firing has received great attention from boiler manufacturers as a clean coal technology (CCT) option. This research aimed to produce biocoal pellets, as a clean energy fuel, using hydrochar from trees planted to rehabilitate acid mine drainage (AMD) water and fine coal discards. The hydrochar was synthesized by hydrothermal carbonization of Searsia lancea harvested from AMD-contaminated land at a temperature of 280°C and a residence time of 90 minutes. It was blended with discard coal (–1 mm) at ratios of 25% and 50% hydrochar to produce different forms of solid pelletized biocoal (BC). The physicochemical and mechanical properties of each of the biocoal pellet blends were determined. The 100% hydrochar had the highest calorific value of 29.99 MJ/kg, while the raw discard coal had a calorific value of 16.73 MJ/kg. The ash content decreased from 42% in the discard coal to 25% in the blend of 50% coal and 50% hydrochar biocoal pellets. Biocoal pellets comprising 25% hydrochar and 75% discard coal (BC25 HC/75 COAL) displayed the best mechanical properties (compressive strength 3.06 MPa) of all the fuels, but the physicochemical properties were inferior to the BC50 HC/50 COAL pellets. This research has demonstrated that hydrochar synthesized from a tree species planted for hydraulic control of AMD has the capability to act as a binder for improving the mechanical properties and energy characteristics of fine discard coal.

Dec 1, 2021

By M. Bhandari, D. Norval

The bulk of plain carbon steel is produced through conventional Basic Oxygen or Electric Arc Furnace routes where the development of the AC Ladle Furnace has made it possible to also produce alloy steels. Smaller Ladle Furnaces have limitations such as lower efficiency; high electrode consumption and diminutive yields rendering them uneconomical to operate and making the processing of low carbon steel grades difficult due to carbon pick up. The demand for special steels and alloys with strict specifications is increasing while commodity prices remain competitive. The production of special steels and alloys have specific process control requirements and the development of the induction melting furnace (IMF) has made it possible to produce smaller batches economically. Refining and alloying of the melt in the IMF further enhance the efficiency. The INDUREF furnace offers increased productivity and flexibility through increased thermal efficiency and can be utilised for holding molten metal for further processing such as granulating, atomising, nitriding, alloy additions and desulphurisation of Ferro-alloys and steels. The system utilises a specially engineered ladle which is placed in an induction-heating assembly comprised of a stationary water-cooled copper coil and lamination packs. The addition of equipment for vacuum degassing and decarburisation of steels and alloys is also feasible. Benefits are: ? No electrode consumption or carbon pick-up ? Lower installation, operation and maintenance cost. ? No line-flicker facilitates operation on a weak power grid. ? Good power factor and balanced load ? No skull formation and reduced refractory consumption ? Higher yield of Fe-alloys ? Automatic controlled stirring

Jan 1, 2004

By R. L. Pienaar

Paper written on project work carried out in partial fulfilment of B Eng (Min. Eng.) degree A study was conducted to investigated and compare the feasibility of two single level extraction layouts for an intact part of theorebody of the De Beers diamond mine, Koffiefontein. Two layouts were chosen and the tonnage profile, development schedule and production ring blast layouts were calculated by applying the information acquired through a literature study. Current principles used on the mine were also applied. The first layout chosen is described as a simple straightforward layout with 6 production tunnels spaced 15 m apart, and is referred to as Layout A. The second layout, named Layout B, is described as a complex chevron layout with 9 production tunnels spaced 15 m apart. This layout has a rim tunnel situated in the kimberlite ground, which is called a chevron and this made the layout more complex than Layout A. By comparing the financial results of the two layouts, it was found that Layout B is a more feasible option than Layout A. Sensitivity analyses show that both layouts are extremely sensitive to the revenue of the projects. Therefore it is recommended that Layout B can prove to be a source of additional tonnage to add to the total tonnage profile of the mine and to extend the life of mine by 20 months, only if certain financial/economic factors improve. There is, however, still some areas of the project that need to be investigated.

Jan 1, 2006

The South African Institute for Mining and Metallurgy celebrated its 95th anniversary with a banquet at The Carlton on Friday, 2nd June, 1989. This event was attended by 600 people, including the Presidents of AS&TS, constituent societies, and other kindred bodies, together with members and their guests. The guest speaker was Mr Muray Hofmeyr, Chairman of the Johannesburg Consolidated Investment Company Limited, who gave an interesting and thought-provoking talk entitled 'Will we still be the best in the year 2001'

Jan 1, 1989

OFS Branch Proceedings of the Annual General Meeting ofthe O.F.S. Branch on Wednesday, 31st July, 1974. The Annual General Meeting of the Branch was held at the Western Holdings Limited Canteen on Wednesday, 31st July, 1974 at 7.30 p.m. Mr E. T. Wilson (Chairman) was in the Chair. There were also present: Papers of interest The following papers may be of interest to members. Education fund The Institute has recently brought into being a Fund to finance various educational projects.

Jan 5, 1974

By P. J. Barton, N. F. Peverett

A brief review of the development and ultimate design of the Model 16 Photometric Sorter is given, including the differences between it and its predecessor, the Model 13, which is currently in operation at Doornfontein. A description of the West Driefontein sorting plant is given, together with the rationale of its design. The installation programme for the sorters is described, and current operating and maintenance procedures are discussed. Operating results are tabulated and compared with the original test results. Operating costs are also discussed.

Jan 1, 1980

By H. Knorre, A. Griffiths, R. Higgins, S. Gos

Hydrogen peroxide is gaining acceptance as a reagent for the treatment of mining effluents containing cyanide. In this paper some of the chemical and environmental aspects of treatment with hydrogen peroxide are discussed, and one way of improving the economics of the process is described. This is known as selective detoxification, which involves the oxidation of the less stable (cyanide) complexes while not affecting the more stable complexes, which contribute very little to the concentration of free cyanide or to the toxicity of the treated water.

Jan 1, 1987

The FSPE Award for Services to the Engineering Profession was awarded to Or Francis George Hill at a ceremony held in January of this year by the Federation of Societies of Professional Engineers. The following is an abridged version of the citation made by Professor A.N. Brown, President of FSPE, and of Or Hill?s reply. Achievements. It is indeed fitting that such a distinguished group of people have gathered on this special occasion to honour and pay tribute to Or Pinkey Hill

Jan 1, 1988

By J. G. Goodey, G. J. van der Linde

This paper describes pilot-plant tests on the recovery of apatite from a hitherto untapped material. This materialhydro- separator overflow-is very fine (80 per cent smaller than 45 µm and 32 per cent smaller than 10 µm). . The pilot-plant tests proved that the recovery of apatite from this material is economically and technically viable. This was confirmed by plant trials, which, in the early stages, produced concentrate assaying 36,6 per cent P2O5 at a recovery of 65,5 per cent.

Jan 1, 1983

By I. J. A. Brackley

An investigation of the slope stability of a pit and failures of spoil dumps, carried out at Silicon Smelters quartz mine, Pietersburg, South Africa, is described. The major geological feature of the mine is the intensely foliated schist in the footwall, with exceptionally Iow strengths upon extensive discontinuities, and the similarly unusual strength properties of the dumped schist spoil. The selection of slope angles for the pit is described, and a proposal for the stabilization of the failing spoil dump by segregated dumping is explained.

Jan 1, 1985

By M. R. Khalesi

A method is proposed to estimate the gold content of the ore in the size intervals during size reduction. The method uses the population balance model to trace the gold deportment through the size fractions and monitor the generation of liberated gold grains during the size reduction. The model is calibrated using batch grinding test results of a gold ore. Preliminary results show that the model can be calibrated with a minimum of parameters compared to conventional grinding-liberation models. Keywords: simulation, liberation, gold, exposure, grinding

Jan 1, 2009

By Donald Sir Tebbit

To have been invited to deliver this second CMMI lecture is an honour that I deeply appreciate. But, when I contrast my qualifications for delivering it, with those of Sir Alistair Framet, who delivered the inaugural lecturet in the series, or with those of other members of the Council, I feel rather an imposter. Far from having been a miner al my life, I have been associated with the mining industry on a part-time basis for a mere eight years. However, I encourage myself with two recollections. The first is the admission of the great Sherlock Holmes that he was often guided to the truth by the erroneous opinions expressed to him by Dr Watson. I may be able to perform a similar service for you. Secondly, I recall that, when I was a member of the Diplomatic Service, I was quite often asked to address representative gatherings of such professional people as the police, architects, dress designers, teachers, doctors, funeral directors, bird fanciers, and so on. Since it would have been pointless to pretend that I was expert in any of their businesses, I used to resort to the technique of announcing as my theme' A diplomat looks at the police' or whatever profession it was. They fortunately took it as a compliment that their profession was apparently one that diplomats spent a lot of time brooding over. They could also afford to laugh of any criticism that I might make because it could be ascribed to ignorance rather than informed malice. I hope that you will do the same.

Jan 1, 1988

By J. Levin

The Bond standard grindability test provides a Work Index that is widely used to estimate the energy required for grinding, but the test cannot be applied to fine materials such as plant tailings and middlings. For such materials, a comparative grinding test must be used in which a reference material from an operating plant is ground in a laboratory mill to determine the 'equivalent' energy consumption per revolution of the laboratory mill. As the Bond grindability test mill and its operating conditions are specified, its equivalent energy consumption per revolution should be a constant, here designated as B. Once B has been determined, the mill can be used to estimate the grindability of fine materials without the need for reference materials. A value of B can be calculated from any Bond grindability test, and 245 tests that were conducted at Mintek were examined to determine its value. A wide range of values was found, but most of them were grouped around 198 x 10- 7 kWh/rev, which is taken as the best estimate of B that is available at present. Values of B that are not close to this figure are obtained from materials for which the Bond grindability test gives misleading or 'spurious' Work Indexes. These spurious Work Indexes lead to the apparent departure of B from its true value. Some limitations of the Bond grindability test arise from its use of a mill without litters and of screening, instead of classification, to close the circuit.

Jan 1, 1989

By S. L. Miller

The development of a pilot gold geostatistical ore reserve system proved that geostatistical methods worked well for the routine production of annual ore reserves on gold mines of the Gold Fields of South Africa (GFSA) group, and that the techniques could also be practically implemented, understood and accepted by Survey Department personnel. Many side benefits of the pilot system became apparent, and a variety of useful management information was provided by manipulating the data values that were already captured. It was decided that it was a priority computing project to develop a standard production system (GORS) for routine use by all the GFSA gold mines. Experience with the pilot system enabled detailed functional specifications for GORS to be laid down. These, together with group computing policy determined the terms of reference and constraints for the GORS development. System design could not be finalized until new and appropriate mainframe database software and graphics workstation equipment and software had been found. With these in place the basic system was structured to take best ad- vantage of the interactive features of the workstation, the number-crunching power of the mainframe and the flexibility offered by a relational database and associated 4GL tools. Application sub-systems were developed for data capture, statistical applications, geostatistical calculations, contour plotting and graphical queries. GORS is being introduced to the mines in a phased manner with suitable documentation, training and support structures to enable it to be routinely and effectively used on a day-to-day basis by all group gold mines.

Jan 1, 1987

By Steve Konieczki

[ ] Great Basin Gold Ltd. (GBG) owns the Hollister Mine and operates it through the wholly owned subsidiary Rodeo Creek Gold, Inc. The property is located in northern Nevada on the Carlin Trend gold belt within the historic Ivanhoe Mining District. The mine is located on the western edge of the Northern Nevada Rift, a major north-northwest trending structural zone that has localized middle Miocene volcanic rocks and numerous epithermal gold deposits. The precious metal deposits are low-sulfidation epithermal systems characterized by banded quartz veins with electrum and silver selenides. The Hollister Mine will employ the selective underground mining method of cut and fill. This will be combined with split shooting (resuing mining method) to optimize recovery and reduce dilution. The focus of mining will be on extraction of ?ounces? from the narrow-veins rather than trying to maximize tons. The initial drifts will be excavated along the strike of the vein and then capped with a substantial concrete sill pillar. Back stoping with hand held drills will be used to selectively mine the vein. The stopes will be backfilled with waste rock material. With every lift, an 18 inch concrete cap will be poured onto the backfill waste rock to prevent gold values from being lost into the fill. Targeted ore production rate will be over 400 tons per day. With current ore reserves, project life is estimated to be around eight years; however, Hollister geologists view the site as one of the most prospective systems for bonanza vein deposits in Nevada. Approximately $14

Jan 1, 2008

By L. I. Boshoff, S. Gracie

This paper discusses pilot and laboratory-scale metallurgical test work conducted on bulk samples from a low grade heavy mineral deposit and provides an overview of basic practical metallurgical techniques applied to ascertain the suitability of existing production plants to process material from this orebody. Previous investigations have shown this specific orebody to be more challenging in terms of mineral beneficiation as it has a high gangue mineral content. Test work was conducted on targeted stratigraphic units based on lithology and assay results to enable identification of the stratigraphic units portraying quality issues. Unit specific metallurgical pilot work has never been conducted on any of the RBM orebodies and is a new field currently being explored. During this investigation focus was placed on potential quality and yield issues for ilmenite product, with particular reference to CaO quality. A basic evaluation of zircon and rutile separability was also conducted. The test work was conducted using a comparative baseline methodology with metallurgical test work methods specifically aiming at mimicking the existing production plant as closely as possible. This enabled not only the likely metallurgical performance to be assessed but also indicated whether current plant design would be suitable to process the low grade ore types into products of acceptable quality at acceptable yields. The methods and findings discussed in this paper indicate that although there is considerable variation between different units, a blended feed can be successfully processed. With unit specific metallurgical data applied to the existing geological block model, expected yields and recoveries using current plant designs could be predicted.

Jan 1, 2007

By D. H. Diering

The paper deals with the technologies required for opening up anew idealized ultra-deep level mine. First the overall philosophy of accessing ore at ultra depths is discussed. Then the individual technologies which will be required are explored. Finally a detailed overview on one of the key technologies, namely tunnel support, is given. Because this project is still in its infancy, few definitive answers are provided; instead each of the envisaged technologies are briefly discussed, with emphasis on those which require the element of speed for rapidly accessing the ore body.

Jan 1, 1997

By D. deV. van der Spuy

A procedure for optimizing the secondary cooling zone of continuous casters is proposed and illustrated by a billet caster example. The procedure consists of quantifying deviations from the required conditions of the secondary cooling zone?as far as temperatures, metallurgical length and reheating are concerned?by means of a ?cost function?. The optimal spray settings are then found by minimizing the total ?cost?. The billet caster examples serve to emphasize the importance of specifying the required conditions in a consistent manner. Some envisaged practical limitations of this approach are discussed.

Jan 1, 1999

By G. Wu, S. Liu

In view of the singleness of traditional methods about international petroleum (Brant) price forecast, ten main factors that affect international petroleum price are fully analysed. Based on time series method and multivariate linear regression method, the simulation model with the theory and idea of system simulation is firstly established. And this forecasting system realizes visual operation under the environment of MATLAB/SIMULINK. So this article tries a new way for further exploring petroleum price’s running law and guiding its forecasting practice. Keywords: Petroleum price forecast, system simulation, residual error, physical flows information flows

Jan 1, 2003