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By M. Berjak, D. M. Hawkins, V. E. Marting, R. B. MacGillivray

Contributions to discussion V. E. Marting (Associate Member): The authors of this paper should be congratulated in having pioneered the application of the Sharapov predictor to local data, and in having made a valuable contribution to South African experience in the quantitative treatment of geological information using a digital computer. Although the existing set of three programmes has been described as a 'suite' it does not represent an integrated system in the accepted sense since the communication between runs is made in the form of punched card files to enable the mining engineer to exercise discretion and control over the data entered at each phase. Although the authors are justifiably proud of the successful results obtained through the application of this method, I feel that it is my duty to comment that the computer aspect of the work has not reached full development and is deserving of the financial support needed to increase its widest usefulness. At the present moment a routine to detect 'missing information' has not been commissioned. Due to the lack of documentation the use of the programmes is restricted since the format for the submission of data is known only to the authors. It is very unlikely that a profitable return on the development costs will be enjoyed before the programme is fully documented and made available to wider use. My criticism of the present incomplete state of the work is being voiced purely with the intent of focussing on the significance of this project and the fact that it is deserving of development on an industry basis. It should be noted that at the economical cost of R4.00 per sq ft of computer print-out, a mining engineer can hardly afford to miss the opportunity of using the programmes on other (e.g. metalliferous) mineral deposits of tabular formation. Since the publication of this paper I have had an opportunity to see the results of the programmes developed by Drs M. D. G. Salamon and F. Deist for designing bord and pillar workings. The basic data for these latter programmes are extracted from iso-line plans drawn conventionally by geologists, a task that could be considerably expedited through the use of Mr Hawkins' programmes. It appears that the efforts of these respective teams are complementary and it is in the interests of the industry that these individual components should eventually form part of an integrated system. E. Margo* (Member): This paper is a good example of how and where the backroom scientist-in this case the mathematical statistician-can aid the mining engineer to develop not only more accurate means for dealing with valuation problems but to develop a tool that can also cope with changed geological specifications.

Jan 1, 1969

The Annual General Meeting of the Institute was held in Kelvin House, Johannesburg, on Wednesday, 25th August, 1971, at 4.15 p.m. Mr V. C. Robinson (President) was in the Chair. There were also present fifty one Fellows, twenty one Members, two Associates, two Students and fourteen Visitors, making a total of ninety one. The President declared the meeting open at 4.15 p.m. OBITUARIES The President: 'It is my sad duty to announce the death of the following members of the institute: H. J. G. C. Arndt, Life Member, joined 1933, passed away 11th May, 1971. J. H. A. Diering, Fellow, joined 1921, passed away 24th June, 1971. L. O. W. Leimer, Fellow, joined 1960, passed away 25th June, 1971. E. A. Meltzer, Fellow, joined 1941, passed away April, 1971. As a mark of respect to the memory of the deceased and in sympathy with the bereaved, I would ask you to rise and observe a few moments silence.' MINUTES The President: 'May we confirm the minutes of the General Meeting held on 17th March, 1971, as published in the July, 1971 issue of the Journal?' Agreed. WELCOME TO VISITORS The President: In welcoming you here, ladies and gentlemen, it gives me great pleasure to see so many of our office bearers-our important honorary office bearers-and particularly I would like to welcome our Honorary President, who is, as you know, the President of the Chamber of Mines, Mr John Shilling, and we are 'privileged also to have with us two of our Honorary Vice-Presidents. One in particular I am very pleased to welcome here, and that is Mr G. F. van L. Froneman, who is the Administrator of the Orange Free State, and we extend a very hearty welcome to him, because he is a long way from home. Then we have another Honorary Vice-President, Mr Tommy Gibbs, the Government Mining Engineer, and there are many distinguished guests, whose names I want to give you, so that you will know who they are. We are happy to have present: Mr R. C. J. Goode, Member of Council, I.M.M. London; Mr E. Boden, Manager, A.S. & T.S. of S.A.; Mr G. A. P. Louw, The President, The Associated Scientific and Technical Societies of S.A.; Mr I. R. G. Stephen, The President, The South African Institution of Electrical Engineers; Mr A. S. Robinson, The President, The South African Institution of Civil Engineers; Mr C. F. J. Schneider, The President, The Institute of Land Surveyors of the Transvaal; Mr R. J. Vermaak, The President, The South African Institute of Assayers & Analysts; Prof J. P. F. Sellschop, The President, Joint Council of S.A. Scientific Societies; Mr T. C. Watermeyer, The President, The Federation of Societies of Professional Engineers; Mr G. A. MacWhirther, The President, S.E.I.F.S.A.; Mr C. G. Hinds, The President, The Mine Managers Association; Mr J. F. Aldersley, The President, The South African Institute of Foundrymen; Dr H. O. Reisener, The President, The Institute of Welding; Dr F. P. A. Robinson, The President, S.A. Corrosion Council; Mr A. Bain, The Chairman, Witbank-Middelburg Branch; Prof D. J. Schoeman, The Chairman, The S.A. Institution of Chemical Engineers; Dr N. P. Finkelstein, The Chairman, The South African Chemical Institute (S.Tvl Section); Mr J. M. Meyer, Chairman, O.F.S. Branch. To all these guests and their ladies, I extend a most cordial welcome, and hope that you are going to enjoy the afternoon. MEMBERSHIP The President: 'I have pleasure in announcing that the names of the following candidates having been published in accordance with By-Law 5.2.2., Council has elected them to membership in the following grades: Fellows: Richard Lloyd Blandy, Byron J. Haley. Members: Brian Roger Borton, Frederick Brian Peacock, Peter John Stacey, Kenneth Niles Thanstrom. Students: Peter Boesley James, Kenneth Brian Perel. TRANSFERS From Member to Fellow: Cecil Eugene Fivaz, Peter Edwards. I wish to welcome the new members to the Institute and to congratulate those members who have been transferred to a higher grade. ANNUAL REPORT OF THE COUNCIL AND ACCOUNTS FOR THE YEAR ENDED 30TH JUNE 1971 THE PRESIDENT: We now come, ladies and gentlemen, to the annual report of the Council of the Institute-and our accounts for the year ended 30th June, 1971, and these documents are on your chairs; I know you probably haven't had time to study them yet, but I would like to highlight some of the things which I think are worth mentioning. I would ask you to take, first of all, ladies and gentlemen, the report of the Council as being read, and before moving adoption, however, there are certain salient points I wish to touch on, and I will leave the financial side of this entirely to our very competent and worthy, Honorary Treasurer, Mr Denis Maxwell.

1. Book reviews Mining and metallurgical practices in Australasia. Melbourne, Australian Institute of Mining and Metallurgy, 1981. $40 (incl. surface postage). Reviewer: M. G. Atmore Coal mine ground control, by Syd. S. Peng. 1978. Reviewer: C. F. Engelbrecht Sixth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity, July 31 -August 2, 1979. Pittsburgh, School of Engineering of the University of Pittsburgh, 1980. Reviewer: S. T. J. van Rensburg This book is a useful general reference volume on the topics covered provided a great deal of technical detail is not required from it. It consists of 29 papers, which are arranged under 6 headings. Flotation agents and processes. Technology and applications, edited by M. W. Ranney. Park Ridge, D.S.A., 1980. $48. Reviewer: R. P. King 2. New books Project control manual, by Sven R. Red. 250 pp. in loose-leaf binder. U.S. Al47. (Obtainable from the author at Bray Studios, Windsor Road, Windsor SL45 UG, England.) Manganese deposits, by Supriya Roy. London, Academic Press, 1981. 400 pp. Joint preparation for welding (set of overhead-projector transparencies). Abington (England), The Welding Institute, 1980. £34 per set. Electron micrographs of clay minerals, by T. Sudo,S. Shimoda, R. Yotsumoto, and S. Aita. Amsterdam, Elsevier, 1980. 228 pp. Dfl.150. Weld pool chemistry and metallurgy. Abington (England), The Welding Institute, 1980. 357 pp. $27. 3. New journal ...being known as Gliickauf + Translation, at an annual subscription of 396 DM for 24 issues per year. It is available from Verlag Gliickauf GmbR, D-4300 Essen I, P.O. Box 103945, Federal Republic of Germany. 4. Canadian MRI publications During 1980 the Mineral Policy Sector introduced a new series of reports identified by the prefix MRI. These cover internal studies and analytical works on a wide variety of subjects, that for one reason or another, do not reach the publication stream of the regular series yet may be of interest to readers in this 'unpublished form'. Twenty-four such titles are listed below. Exploration planning A series of professional advancement seminars for the mineral industry is to be held at Rhodes University from 12th to 20th August, 1981. The series, entitled 'Economic Guidelines for Exploration Planning', will be conducted by Professor B. W. Mackenzie, and the attendance will be limited to 30 participants. The seminars are intended Seminar on Geostatistics A seminar for mining executives on Geostatistics and Decision Making in the Mining Industry is to be held in Toronto from 23rd to 25th September, 1981. v

Jan 1, 1981

By N. W. Munro

SYNOPSIS Certain disadvantages associated with the use of Anfex have been raised on previous occasions. This interim investigation shows that by loading at lower pressures the sensitivity to initiation of Anfex can be improved. Associated with this is a reduction in velocity of detonation and charge density which should lead to more desirable fragmentation. The effect of lower loading pressure on other factors is also considered. INTRODUCTION Discussion at the Symposium on the use of Anfex in Underground Mining, conducted by the South African Institute of Mining and Metallurgy during May 1968 showed that there was considerable uncertainty and diversity of opinion on the characteristics of Anfex and its method of application. Some of the disadvantages associated with the use of Anfex were: Inadequate sensitivity to initiation; Excessive fragmentation of the rock and damage to the hanging and footwalls; Wastage as a result of blow-back; Poor water resistance. As a result of this, further investigations on the properties of Anfex have been carried out and, although these have not reached finality, it is considered that a progress review may be of interest and assistance to the mining industry. EXPERIMENTAL TECHNIQUE The work was carried out on a laboratory-scale where, for test purposes, the explosive was loaded into 1 in. (nominal) internal diameter steel pipes unless otherwise stated. Charging was conducted with a 1 in. (nominal) Schutte-Koerting eductor having a 0.2 in. internal diameter venturi nozzle, the Anfex being fed into the eductor from a conical hopper fitted directly above it. A 5 ft long copper loading tube with outside and internal diameters of 3/4 in. and 5/8 in., respectively, was fitted to the discharge end of the eductor. The remote end of the loading tube was inserted into the test pipe so that it was about 6 to 8 in. from the closed end of the pipe. The loading apparatus was withdrawn as the pipe filled, maintaining approximately the same stand-off distance throughout the operation. REVIEW Sensitivity to initiation Sensitivity of Anfex to initiation was found to deteriorate when the dynamic pressure of the air to the eductor was increased. This was attributed to increasing charge density and it was found that at a charge density of about 1.05 g/cm3, which

By R. T. Tshikhudo

Nanotechnology can provide solutions to many of the world?s socio-economic challenges. The application of nanomaterials for water treatment and analysis, point-of-care diagnostics and targeted drug delivery systems or devices could improve the quality of life for people in developing countries. Gold colloids have a long history (dating back to the 4th century AD) and are particularly well known for their aesthetic appeal and their therapeutic properties. Since Faraday published a report on the synthesis and properties of colloidal gold in 1857, a reasonable insight into the nature of gold sols (nucleation, growth and kinetics of coagulation) has been developed. Considerable attention has been drawn during the past few decades to the development and optimization of methods for the preparation of gold nanoparticles. In nanoscience and nanotechnology today, gold nanomaterials appear to be the most widely used material by both academics and industrialists. This is due to the extraordinary properties of gold nanoparticles (e.g. optical, catalytic, and magnetic?they are also known to act as strong Raman enhancers and may also amplify fluorescence under certain circumstances). Mintek, through Project AuTEK and the DST/Mintek Nanotechnology Innovation Centre (NIC), has been at the forefront of the development of new industrial uses for gold. Mintek?s gold nanotechnology programme focuses on the development of gold-based nanostructured materials and their applications in health, water and other related areas. While few projects use gold nanoparticles for water treatment and analysis, Mintek?s gold nanoparticles are widely used in the health sector. For example, gold nanoparticles are engineered and produced in large quantities as systems for targeted drug delivery. They are also used as tools for advanced rapid diagnostic tests. Both optical and electrochemical rapid diagnostic methods are developed for the human and animal health sectors for point-of-care testing. This paper gives a brief introduction and overview of gold nanotechnology, and desrcibes the development of some of Mintek?s gold nanoparticle targeted drug delivery systems and lateral flow point of care prototype devices.

Jan 1, 2009

By A. P. Cook

Gas samples were taken from a wide range of target areas on dumps arising from coal mining activities. Some of the dumps had largely burned out, some were still burning, some were in the process of rehabilitation, and on others rehabilitation was essentially complete. It was found that rehabilitation was very effective in reducing emissions to tolerable levels. Even incomplete rehabilitation reduced the CO2 emissions to less than about 1 kg/m2/a, whereas some unrehabilitated areas showed emissions of over 100 kg/m2/a. Some areas where there was active combustion taking place were also sampled, and they showed as much as 7 000 kg/m2/a, but the areas concerned were very small and their total contribution accordingly low. Analyses were also made for SOx, NOx, NH3, and CH4, but these were generally (and unexpectedly) at very low levels. The mines sampled represented 53 per cent of all surface coal mining activity. Accordingly the estimated total emissions were scaled up, to arrive at estimates of 1950 000 ± 350 000 t/a C02, 2040 ± 580 t/a SOx, 306 ± 85t/a NOx, and 31 ± 9 t/a NH3 for all surface mines. Methane was detected only from burning coal, and due to the difficulty in sampling, no reliable estimate could be made of these methane emissions.

Jan 1, 2012

The Annual General Meeting of the South African Institute of Mining and Metallurgy was held in Kelvin House, Johannesburg, on Wednesday, 19th August, 1981. Dr P. R. Jochens (President) was in the chair and declared the meeting open at 4.05 p.m. This account of the proceedings includes only those matters that are not reported under the heading `Annual report and accounts' elsewhere in this issue. Confirmation of the Minutes The minutes of the last Annual General Meeting, which was held on 27th August, 1980, were confirmed as pub¬lished in the September issue of the Journal. Welcome President: I extend a sincere welcome to you all, especially to the following distinguished guests: Mr L. W. P. van den Bosch, President of the Chamber of Mines, and Mrs van den Bosch; Mr J. G. Kirchner, Government Mining Engineer, and Mrs Kirchner; Dr William Ble¬loch; Dr L. Alberts, President of the National Institute for Metallurgy, and Mrs Alberts; Dr C. F. Habis, Presi¬dent of the CSIR, and Mrs Habis; Dr P. J. Hugo, Chief Director of the Minerals Bureau, and Mrs Hugo; Mr D. N. Stuart, General Manager of the Chamber of Mines, and Mrs. Stuart; the Presidents and representatives of other Institutes and their wives; and Honorary Life Fellows of our Institute and their wives.

Jan 1, 1981

1. USSR co-operation International Mining, the London-based publication, has received USSR Government approval to publish a Russian language edition for circulation in the Soviet Union. 2. Mintek publications Special Publication no. 11. World chromite resources and ferochromium production, by M.H. Silk. 1988. 160 pp. South Africa RlOO including postage; elsewhere US$lOO including postage. Application Report 4 The development and implementation of novel refining processes for the platinum-group metals (including the refining of anode slimes). 1988. 16 pp. Report M249D The acid activation of local clays including solid-liquid separation, by P.M. Cole and G.F. Lahoud. First issued Mar. 1986, reissued Apr. 1988. 46 pp. ReportM250D The production of refined feromanganese in a transfered- arc plasma furnace, by A.F .S. Schoukens and M.Ford. First issued Mar. 1986; reissued Apr. 1988.23 pp. ReportM257D Extraction of gold from eastern Transvaal concentrates by roasting and cyanidation, by J.J. Robinson. First issued Apr. 1986; reissued Apr. 1988. 55 pp. ReportM267D The recovery of gold from backfil by gravity separation, by R.N. Guest. First issued Jun. 1986; reissued Apr. 1988. 18 pp. ReportM285D Autogenous miling of kimberlite, by D.I. Hoyer. First issued act. 1986; reissued Apr. 1988. 11 pp

Jan 1, 1988

Orange Free State Branch Minutes of a General Meeting held at the Welkom Mine Canteen on Wednesday, 21st November, 1973, at 4-.00 p.m. Present Mr E. T. Wilson (Chairman) in the Chair, 15 Fellows and Members, 12 Associates, Graduates, and Students, and 11 Visitors (Total 38). Book review Symposium on Environmental Engineering in Coal Mining The 20 papers presented at the symposium cover some 14 subjects related to environmental engineering in coal mines, such as dust, heat, gas emissions, ventilation, noise, and lighting. Competition for students Each year the Institute offers a prize (or prizes should the entries warrant it) of up to Rl00 for the best paper or dissertation on a topic appropriate to the interests of the Institute. A.8. & T.8. Trust The A.S. & T.S. Trust has been formed with the specific object of establishing a worthwhile source of funds which can be used to further the progress of science and technology in South Africa. Nim reports Report No. 1573 A pilot-plant investigation of a flotation model. Report No. 1597 The role of sulphur in the flotation of sulphide minerals. Report No. 1599 The analysis of silicate rocks and metallurgical slags by X -ray-fluorescence spectrometry. Report No. 1607 The analysis of ion-exchange resins by X-ray- fluorescence spectrometry. Report No. 1617 An electronic differential precision thermometer.

Jan 6, 1974

By R. Hewer

Transition metals have been widely used in medicine throughout history. The medicinal use of metals extends back to the earliest recorded history when the Chinese used gold as treatment for a variety of ailments. The ancient Egyptians used copper to sterilize water and mercury was reportedly used by Hippocrates in 400BC. Thereafter, numerous other metals have been used as treatment throughout the centuries. For example, zinc sulphate was used as an emetic in the 17th century and zinc oxide was used to treat epilepsy in the 18th century. This use of metals, and numerous other instances, which have been well described in Sneader 2008,1 make for interesting reading but largely occurred prior to the advent of rigorous scientific method. Therefore, although there are exemptions, most therapeutic applications of metals prior to the modern age lack scientific grounding and have been found to be mostly ineffective. Of more relevance are metal-based medicines approved by regulatory bodies (i.e. Food and Drug Administration; FDA) that are in current use as therapeutic drugs. There are presently a large number of metal-based drugs that are approved for use by the FDA ranging from over the counter medicines, such as bismuth subsalicylate for gastrointestinal problems, to prescription drugs such as lithium carbonate for the treatment of manic depression. The list of metal-based medicines approved by the FDA not only incorporates base metals but also includes precious metals. Platinum complexes have been found to be potently active against several different types of cancers while gold complexes have shown application as treatment for rheumatoid arthritis (RA). With the well-established foundation that exists for metal-based medicines, it is imperative to continue exploration into new therapeutic areas. The precious metals; gold, ruthenium and platinum, continue to attract scientific interest in the field of biomedicine and have been widely researched. Scientific studies conducted on gold complexes have demonstrated the potential of this metal for the treatment of HIV/AIDS, cancer and malaria. These diseases are also specific health concerns for developing nations; countries where disease has devastating impact. Within South Africa alone, an estimated 5.7 million people are infected with HIV/AIDS,2 approximately 7 000 new cases of malaria are reported annually, and it is projected that 1 in 4 persons will develop cancer. Continuous development of therapeutic drugs to combat these diseases is therefore apriority, and the exploration of gold-based compounds for this purpose is warranted.

Jan 1, 2009

ENERGY 73 The First International Energy Exhibition will be held in Brussels from 13th to 18th May, 1973. Vllth INTERNATIONAL CONGRESS ON CYBERNETICS This congress will be held in Namur, Belgium, from 10th to 15th September, 1973. GRADUATE SCHOOL OF BUSINESS ADMINISTRATION University of the Witwatersrand The Sixth Executive Development Programme is scheduled to take place from 2nd July to 24th August, 1973. IFAC SYMPOSIUM 1973 Second announcement ofthe International Symposium on AUTOMATIC CONTROL IN MINING MINERALS AND METAL PROCESSING to be held at the University of New South Wales, Sydney, Australia, from 13th to 17th August, 1973. MINERALS AND ENVIRONMENT The effect ofthe mineral industry on the environment and mineral resources The Institution of Mining and Metallurgy, with the co-operation of the Institute of Quarrying and the Institution of Mining Engineers, will hold a Symposium "Minerals and the environment" at the Institution of Electrical Engineers, Savoy Place, from 4th to 7th June, 1974. COLLOQUIUM ON SLlMES DAMS The South African Institute of Mining and Metallurgy have great pleasure in advising members that a two-day colloquium on slimes dams is bei ng arranged for the 14th and 15th November, 1973. INTERNATIONAL SOLVENT EXTRACTION CONFERENCE This conference will be held at Lyon from 8th to 14th September, 1974. Particulars may be obtained from the Secretary: Dr A. Naylor, British Nuclear Fuels Ltd., Windscale and Carder Works, Seascale, Cumberland CA20 IPG, United Kingdom. Competition for Student Members of the South African Institute of Mining and Metallurgy Each year the Institute offers a prize (or prizes should the entries warrant it) of up to RIOO for the best paper or dissertation on a topic appropriate to the interests of the Institute. Proceedings of the Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) The Proceedings of the APCOM Symposium held in Johannesburg from April 9th to 14th, 1972, have now been published. Members of the Institute may buy the Proceedings at a special price of R12,50 as against the list price of R25,00 to non-members. Verrigtinge van die Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) Die Verrigtinge van die APCOM Simposium, wat op April 9 tot 14, 1972, in Johannesburg gehou is, is gepubliseer. Lede van die Instituut kan die Verrigtinge teen 'n spesiale prys van R12,50 koop, in teenstelling met die prys van R25,00 vir nie-Iede.

The peak in Sulphur price late 2008 caused again intensified investigation into the decomposition of sulphates and spend acid. One option is the recycling of sulphur from spend acid, which already started more than 40 years ago in the field of spend acid from organic processes in refineries and acrylic glass manufacturing. Since this acid couldn't be neutralized and discarded due to high organic contents, another source of SO2 to produce sulfuric acid is the decomposition of metal sulfates. The decomposition of metal sulfates was investigated at the next peak in Sulphur price in the 80?s. The first major scale pilot tests and studies of gypsum decomposition were carried out for clients in Florida. The decomposition of gypsum was quite often mainly influenced by the strategic decision of some countries to get own and independent acid production. In other cases the industry doesn?t have enough space to dump the gypsum. Therefore the company was also forced to convert the gypsum into ?saleable? products to avoid these residues. Other projects were made for the recycling of iron-sulfates from the pigment industry. The motivations for these projects were not only given by acid price. For the German pigment industry it was no longer permitted in the 80?s to dump the iron sulphate residues into the sea. These regulations forced the industry to develop new technology, which allows converting of the FeSO4-residues into iron oxide and acid. Therefore economical and mainly environmental factors influenced the decision of the companies to develop and to build these plants. Beside the above mention iron- and calcium-sulphates many other process exist, which produce metal sulphates as an intermediate product. These cases are not forced by environmental or strategic factors. In cases like Ni, Co or Mn-decomposition the main product of the plant is treated in the decomposition plant and later on used as ferrous-alloys. These final products are higher in price compared to e.g. CaO, which exclude the high-energy consumption for the endothermic chemical decomposition reaction. The reaction of SO2 generation based on acid or sulfate decomposition takes place in the range of 1000°C. The energy demand of the endothermic reaction is considerable and leads due to the high fuel-combustion off-gas stream to a diluted SO2 gas. Energy prices are usually increasing at the same time like sulphur. Sulphuric Acid based on decomposition is therefore more expensive than as acid based on sulphur combustion. The paper describes fluid bed technology and possible process concepts for decomposition plants. Additionally the thermodynamic background of the decomposition process and the main influence factors are provided to receive a better understanding of this technology.

Jan 1, 2009

The peak in Sulphur price late 2008 caused again intensified investigation into the decomposition of sulphates and spend acid. One option is the recycling of sulphur from spend acid, which already started more than 40 years ago in the field of spend acid from organic processes in refineries and acrylic glass manufacturing. Since this acid couldn't be neutralized and discarded due to high organic contents, another source of SO2 to produce sulfuric acid is the decomposition of metal sulfates. The decomposition of metal sulfates was investigated at the next peak in Sulphur price in the 80?s. The first major scale pilot tests and studies of gypsum decomposition were carried out for clients in Florida. The decomposition of gypsum was quite often mainly influenced by the strategic decision of some countries to get own and independent acid production. In other cases the industry doesn?t have enough space to dump the gypsum. Therefore the company was also forced to convert the gypsum into ?saleable? products to avoid these residues. Other projects were made for the recycling of iron-sulfates from the pigment industry. The motivations for these projects were not only given by acid price. For the German pigment industry it was no longer permitted in the 80?s to dump the iron sulphate residues into the sea. These regulations forced the industry to develop new technology, which allows converting of the FeSO4-residues into iron oxide and acid. Therefore economical and mainly environmental factors influenced the decision of the companies to develop and to build these plants. Beside the above mention iron- and calcium-sulphates many other process exist, which produce metal sulphates as an intermediate product. These cases are not forced by environmental or strategic factors. In cases like Ni, Co or Mn-decomposition the main product of the plant is treated in the decomposition plant and later on used as ferrous-alloys. These final products are higher in price compared to e.g. CaO, which exclude the high-energy consumption for the endothermic chemical decomposition reaction. The reaction of SO2 generation based on acid or sulfate decomposition takes place in the range of 1000°C. The energy demand of the endothermic reaction is considerable and leads due to the high fuel-combustion off-gas stream to a diluted SO2 gas. Energy prices are usually increasing at the same time like sulphur. Sulphuric Acid based on decomposition is therefore more expensive than as acid based on sulphur combustion. The paper describes fluid bed technology and possible process concepts for decomposition plants. Additionally the thermodynamic background of the decomposition process and the main influence factors are provided to receive a better understanding of this technology.

Jan 1, 2009

An International Ferro-alloys Congress, arranged by the Ferro Alloy Producers' Association of South Africa, the South African Institute of Mining and Metallurgy, and the National Institute for Metallurgy, will be held in Johannesburg, South Africa, in April 1974. The technical programme, occupying five days, will cover the following topics in relation to all ferro-alloys: 1. Burden preparation, blending, pelletization, handling, reducing agents. 2. Electric smelting furnaces-design, operation, management,- smelting optimization, shop practice, refractories. 3. Mineralogy, reduction behaviour, smelting reactions, slags. 4. Automation, Pollution control. 5. Applications, trends in comsumption, trends in composition specifications. There will be no parallel sessions. Papers in the above topics are invited; review papers will also be welcome. Proposed titles and abstracts in not more than 200 words should be submitted before the 30th of November, 1972, to The Chairman, Programme Committee, INFACON 74, Private Bag 7, AUCKLAND PARK, South Africa. The abstracts will be considered during January 1973, and papers accepted for the Congress must be submitted in final form before the 31st of July, 1973. The proceedings of the Congress will be published as a special volume. There will be a series of post-Congress tours to ferroalloy plants and other places of both technical and scenic interest. A full ladies' programme will be arranged. The First Circular, giving further details, can be obtained from: The Secretary of the Organizing Committee, INFACON 74, Private Bag 7, AUCKLAND PARK, South Africa.

1. Book reviews Quantitative texture analysis, edited by H. ,}. Bunge and C. Esling. Deutsche Gesellschaft fur Metallkunde, 1982. 551 pp. Reviewer: L. 1\'1.Matthews Boundary element methods in solid mechanics by S. L. Crouch and A. M. Starfield. Reviewer: J. A. C. Diering World mineral statistics 1976-1980. Produdion,' exports,' imports, by Institute of Geological Sciences. London, Her Majesty's Stationery Office, 1983. £18.00 Reviewer: R. P. King 2. New publications Canadian mines,. perspective from 1982. Mineral Bulletin MR 197. Supply and Services Canada, Hull, Quebec K1A 059, Canada. Copper' s changing cost structure, by Commodities Research Unit Ltd (31 Mount Pleasant, London, WClX OAD, England). Petrology of metamorphic rocks, by M. Suk. New York, Elsevier, 1983. 320 pp. U.S. $68.00. Applied geomorphology, by H. Th. Verstappen. New York, Elsevier, 1983.442 pp. U.S.$95.75. Tin and its uses, no. 137, by the International Tin Research Institute. Greenford, the Institute (Fraser Road, Greenford, Middlesex UB6 7AQ, England), 1983. 3. New journals Mining Science and Technology, edited by C. 0, Brawner and B. N. Whittaker, is to be published quarterly in one volume per year by Elsevier. Aluminium, published monthly by Aluminium -Verlag GmbH, P.O. Box 1207, D-4oo0 Diisseldorf 1, F.R. Germany. DM 690.00 per annum. Rock mechanics The South African Institute of Mining and Metallurgy is to hold two schools on 'Rock Mechanics in Mine Management' at the University of the Witwatersrand, Johannesburg, from 23rd to 27th January, 1984, and from 30th January to 3rd February, 1984. The Federation of Societies of Professional Engineers The Federation of Societies of Professional Engineers (FSPE) has been a member of the World Federation of Engineering Organisations (W FEO) for many years and has regularly sent delegates to the biennial conference of that organisation. Second progress report by ASRET The Professional Engineers Joint Council was estabislhed in 1960 and initially its main fWlction was to represent the interests of engineers. Explosives technology The Center for Explosives Technology Research (CETR) has been established at the New Mexico Institute of Mining and Technology (Tech) in Socorro, New Mexico. International Tunnelling Association A conference entitled 'Ita Tunnels 1984' will be held in Caracas, Venezuela, from 2nd to 7th June, 1984. Automation The IFAC Symposium on Automation for Mineral Resource Development is to he held in Brisbane (Australia) from 9th to nth July, 1985.

Jan 1, 1983

VERSLAG- REPORT No. 1365 STUDIES OF INCIPIENT FUSION IN THE SYSTEM CHROMITE- MgO- Al2O3-SiO2-C 5th January, 1972 Investigator: N. A. Barcza SYNOPSIS A fundamental study was made of twelve chromite ores by use of a thermobalance under atmospheric and reducing conditions. It was found that their thermal behaviour under atmospheric conditions can be related to the mineralogical composition of the chromite spinel and the gangue. The overall mechanism of reduction with solid carbon over the temperature range of 1 200 to 1 500°C was shown to be diffusion of carbon through the reaction product. The effects of additions of fluxes and variations in particle size on the kinetics and mechanism of reduction were determined. It was shown that carbon monoxide does not reduce chromite ore up to temperatures of 1 550 °C, and it can therefore be eliminated as the diffusing reducing species. However, the reaction product of reduction, namely a mixed carbide of iron and chromium, was shown to be an effective reducing agent for chromitc ore, while also facilitating the transport of carbon. VERSLAG - REPORT No. 1380 AN ELECTROCHEMICAL MODEL FOR THE LEACHING OF URANIUM DIOXIDE 10th January, 1972 Investigators: C. R. S. Needes, M. J. Nicol SYNOPSIS A correlation between the rate of leaching of UO2 and the electrochemical properties of the oxidant concerned has been derived. This correlation is found to be borne out by experimental results. Certain effects observed in UO2 leaching and hitherto unexplained have been clarified in terms of an electrochemical mechanism. Experiments have shown that the mixed potential of a UO2 electrode gives a measure of the rate of dissolution of UO2. Its significance to commercial practice is discussed. CONCLUSIONS (I) The dissolution of UO2 in the presence of a number of oxidants can be explained in terms of an electrochemical mechanism. (2) The mixed potential of the UO2 electrode is a measure of the rate of UO2 leaching. This principle could be used in the control of industrial leaching operations. (3) A simple treatment has provided a mathematical basis for a fundamental correlation between the rate of U02 dissolution and the chemical properties of the oxidants concerned. This relation has been found to agree well with experimental results. (4) A number of phenomena occurring during the leaching of UO2, hitherto not explained in a satisfactory manner, have now been clarified in terms of an electrochemical mechanism.

Notices STRASZACKERREPORT The Institute has received, for its information, a copy of the following letter, which was addressed to The Federation of Societies of Professional Engineers: REPORT: COMMISSION OF ENQUIRY INTO THE METHODS OF TRAINING FOR UNIVERSITY DEGREES IN ENGINEERING (STRASZACKER REPORT) Geagte Heer, VERSLAG: KOMMISSIE VAN ONDERSOEK NA DIE METODE VAN OPLEIDING VIR UNIVERSITEITSGRADE IN INGENIEURSWESE (STRASZACKERVERSLAG) Second International Symposium on Jet Cutting Technology This symposium, sponsored and organised by BHRA Fluid Engineering, of Cranfield, England, is to be held at St John's College, Cambridge, from 2nd to 4th April, 1974. Competition for student members of the South African Institute of Mining and Metallurgy Each year the Institute offers a prize (or prizes should the entries warrant it) of up to R100 for the best paper or dissertation on a topic appropriate to the interests of the Institute. Techomin 74 - World Mining Fair The above World Mining Fair, under the sponsorship of the International Committee for the Organization of World Mining Congresses and the Peruvian Government, is to be held in Lima, Peru, from 3rd to 12th November, 1974, to coincide with the 1974 World Mining Congress, which is to be held in Lima. NIM Reports Report No. 1435 The determination of chromium, manganese, iron, cobalt, and nickel by atomicabsorption spectrophotometry using the nitrous oxide-acetylene flame. Report No. 1463 Liq'uidus temperatures and activities of manganese (11) oxide in slags associated with the production of high-carbon ferromanganese alloys. Report No. 1467 The spectral analysis of solutions. 1. The analysis of rare-earth minerals. Report No. 1479 Infrared studies of the adsorption of oleate species on mineral surfaces,with special reference to fluorite. Report No. 1483 The South African manpower requirements in extractive metallurgy. Report No. 1484 Cost estimates for the production of copper wirebars from sulphidic ores. Report No. 1486 Review of the jluoro-chemical industry of the World. Report No. 1490 The adsorption of krypton, nitrogen, and water vapour on sodium oleate. Report No. 1491 Technology and economics of the Olaus kiln under South African conditions. De Beers Report The dry grinding of tungsten carbide/ steel combinations with diamond wheels. Metallurgical Directory The Israel Export Institute has just published the first edition of the Israel Metal Industry Directory, which gives pertinent information relating to the 750 Israeli manufacturers of metal products-addresses, annual turnover, and products- and to consulting engineers and export companies specializing in metal products. Visiting Nuclear Scientist The National Institute for Metallurgy has announced that Professor Vincent P. Guinn, of the University of California, is to spend his sabbatical leave (April to June) working with the Activation Analysis Research Group of the National Institute for Metallurgy.

The January General Meeting of the Institute was held in Kelvin House, Johannesburg, on 15th January, 1969 at 4.30 p.m. Mr R. C. J. Goode (President) was in the Chair. There were also present eighteen Members, including Messrs F. P. Bath, H. Britten, J. K. E. Douglas, P. Lambooy, V. C. Robinson, W. T. Stobart and P. W. J. van Rensburg (Council Members), Messrs J. C. Hall, P. C. Pirow, Dr D. I. Legge, Messrs E. R. Rudolph, H. R. Reid, Dr N. Stutterheim, Messrs B. F. van der Merwe, L. W. P. van den Bosch, D. T. Watt, M. Youngworth and T. Zadkin. Two Associate Members, Dr P. R. Jochens and Mr D. A. Viljoen. Two Students, Messrs R. P. W. Henrard and D. Ossin. Sixteen Visitors, including Messrs I. Barnes, B. F. Bath, S. Botha, P. A. du Plessis, K. Edwards, Dr F. S. Fulton, Messrs H. Grant, B. Havenga, L. Kok, Dr D. Lasar, R. Sandler, C. W. Wolhuter and J. D. Young. Secretary, Mr D. C. Visser. Total present: Forty. MINUTES The President: "May we confirm the minutes of the meeting held on the 20th November, 1968, as published in the December, 1968, issue of the Journal?" Agreed. MEMBERSHIP The President: "I have much pleasure in announcing that the names of the under-mentioned candidates, having been published in accordance with By-Law 5.2.2, Council has elected them to membership of the Institute in the following grades: Members: Basil James Jackson and James Petrie Archibald. Associate Members: Ronald Creasy, Hugh Angus McCallum and John Barton Cunliff. Graduate: Hermanus Isak Johannes van der Merwe. Affiliate: Edgar Ramsay. Student: Petrus Daniel Wolmarans. MEMBERS TRANSFERRED TO A HIGHER GRADE From Affiliate to Associate Member: Neil Bradfield and Mervyn Bayard Allman. "I welcome the newly elected members to the Institute and congratulate those members who have been transferred to a higher grade." (Applause). GENERAL BUSINESS The President: "Are there any matters to raise under this heading? If not, we will proceed to the next item on the agenda which is the presentation of today's paper."

By R. J. Davidson, B. Strong

The piloting and eventual large-scale operation of fixed-bed carbon columns for the recovery of gold from plant effluents is described. A fixed-bed carbon pilot plant comprising three adsorption columns was used for the recovery of gold from clarified plant effluent at the Vaal Reefs Exploration and Mining Company (West Division). The effluent ,which contained 0,1 toO,S g/t of gold and less than 10 g/t of free cyanide, was adjusted to pH 8 prior to use. Daily acid treatment of the carbon circuit with 3 per cent hydrochloric acid was shown to have a most significant effect on increasing the gold adsorption. The acid treatment involved a plant downtime of only I to 2 minutes per day. High loadings of gold (up to 30 k g/t) and copper (up to 75 k g/t) were obtained on the leading column, while the gold recoveries averaged 98 per cent over 17 weeks of continuous operation. The subsequent elution of loaded carbon in a pilot elution column indicated the use of abnormally high amounts of the pretreatment reagent (caustic soda and cyanide) used in gold elution. This was attributed to the high loading of copper on the carbon. However, the elution of both the gold and the copper at 110°C with demineralized water as the eluant was satisfactory. In a similar large-scale operation, three fixed-bed carbon columns each containing 4,5 t of carbon were used to treat 80 to 120 t/h of plant effluent with a gold concentration of about 0,15 g/t. Gold loadings of 5 to 6 k g/t were obtained regularly, while the gold recovery averaged 97 per cent over a 12-month period. The capital cost of the plant was recovered in 2 to 3 months. The evidence presented strongly suggests that copper plays a significant role in the adsorption and elution of gold under the prescribed conditions, and in the subsequent precipitation of gold following acidification of the eluates. The formation of a highly insoluble gold-copper complex produced under acid conditions appears to explain many of the observations made in the investigation.

Jan 1, 1983

The following contributions were received to the paper entitled 'Safety in South African mines: An analysis of accident statistics', by H.S. Eisner and J.P. Leger, which appeared in the J. S. Afr. Inst. Min. Metal., vol. 88, no. 1, Jan. 1988, pp. 1-7. Contribution by H. WAGNER* The paper by Dr H.S. Eisner and Mr J.P. Leger is critical of the safety situation on South African mines and portrays the industry as having little concern for the health and safety of its workers. Moreover, the casual reader gains the impression of deliberate misinformation by the industry to the public concerning safety maters. Furthermore, certain socio-economic reasons are advanced for the apparent differences between the fatality and injury rates reported for coal mines in South Africa and those for the United Kingdom. Contribution by S.A. WATTS. Authors Eisner and Leger are to be commended on their paper, which highlights, according to their interpretation, various shortcomings of both the Chamber of Mines accident statistics and those published by the Department of Mineral and Energy Affairs. Authors' Reply We gratefully acknowledge Dr Wagner's contribution to the discussion on our paper. For convenience, we shal use his sequence of comments in our reply. Before doing so, however, it may be useful to explain how our paper came to be written. After the explosion at Hlobane Colliery in 1983, one of us (HSE), in February 1984, was retained by the lawyers acting for some of the dependants of the victims to advise on technical maters relating to the explosion. Contribution by Ms S.A. Wats Some of the points made by Ms Wats have already been answered in our comments on Dr Wagner's contribution. We are fully aware that the number of accidents leading to absences of less than 4 days would be much greater than shown in our bar chart, and are grateful to Ms Wats for drawing attention to the specific exceptions that can make a 1-3 day accident compensable and that are clearly responsible for the relatively low count in that category of the chart.

Jan 1, 1988