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By D. Krebs, Tero Korhonen, X. Yang, A. Kirpala, N. Heino

At present, over 85% of the world’s rare earth oxides are produced from the bastnäsite ores, found mainly in China. Meanwhile, the ion adsorption ores are the most important sources for heavy rare earth production. As the demand for rare earth materials in the world increases, other forms of rare earth deposits will become new potential resources of rare earth production in the future. In this paper, flotation performance of a steenstrupine ore from the Kvanefjeld deposit for rare earth recovery was studied through laboratory bench testwork. The effects of various factors including grinding size and collector dosage on recovery and selectivity of the selected rare earth elements, La, Ce and Y, were investigated. A rare earth concentrate with the grades of La 2.8 wt%, Ce 5.1 wt% and Y 1.0 wt% at recoveries of 80.5% La, 79.8% Ce and 55.3% Y was obtained in optimum conditions. Further potential to improve the efficiency of REE flotation was discussed. Keywords: Rare earth elements, flotation, steenstrupine, Kvanefjeld deposit

Jan 1, 2020

By A. C. Lawrence

A new approach to the -study of human factors in stope productivity by A. C. LAWRENCE B. Econ., D. Com. (S.A.) (Member) The extent of the improvement in mean performance which could be achieved by reducing the variance between stoping gangs is examined, and it is shown that a worthwhile gain would result if variance were reduced by as little as 5 to 15 per cent. The problem of identifying human factors which contributed towards variance in gang performance was examined in one gold mine. A total of 342 'observations' on 49 stoping gangs were gathered, each observation consisting of a set of figures for 36 variables for one gang for one week. The variables included 'stope factors' such as face length, 'gang factors' such as the ethnic composition of the gang, and 'supervisory factors' such as the experience of the miner. These variables were related to 'tons trammed per week' as a measure of work performance. The findings showed that certain of the predictor variables accounted for 66 per cent of the variance in gang performance and about two thirds of this could be attributed to gang and supervisory factors, that is to the 'human factors'. The method suggests a basis for a new approach to the identification of human factors and is a promising step towards optimizing gang performance.

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

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

Jan 1, 2020

By F. Yang, S. S. Long

Mixed fatty acids, such as oxidised paraffin soap, are frequently used as a substitute for oleic acid in flotation of scheelite in China. Not only because it is cheaper than oleic acid, but also because it is superior in flotation performance to oleic acid. This superiority is generally attributed to the mixed fatty acids' synergistic effect. In this paper, the synergistic effect of oxidised paraffin soap was investigated. We found it mainly consists of a series of saturated fatty acid salts, with six to nineteen carbon atoms. All the contained fatty acids were classified into four groups based on their chain length to make the research work practical. Also, the groups were labelled as 1, 2, 3, and 4 in order. The research was simplified into studying the synergistic effect of four equivalent collectors, instead of fourteen fatty acids. It is justified by the fact that neighbouring fatty acids are expected to have a similar flotation performance. The synergistic effect of the four groups of fatty acids was studied by single-mineral flotation with single groups, binary mixtures, ternary mixtures, and the full component, as collector respectively. The flotation performance index and synergy value were introduced to evaluate flotation performance and synergistic effect of groups, respectively. The results show that the mixture 1+2+3 has the strongest synergy of all followed by the mixtures 1+3 and 2+3. The mixture 3+4 and 1+2, on the other hand, have negative synergy. The synergistic effect of mixtures of groups indicate that being consecutive in length and a broad range of lengths are vital for fatty acids to enhance synergy. Group 3 is fundamental for the collecting action of 733 oxidised paraffin soap in the flotation of scheelite. The fatty acid soap in group 4 is not suitable for flotation due to its low solubility. Keywords: Mixed collectors, synergistic effect, scheelite

Jan 1, 2020

By C. Bergmann, V. Ross

The concept of underground ore processing, in which valuable ore and waste are separated at a coarse particle size to improve the economics of operations and minimise the environmental impact, seems attractive from a sustainability perspective. Perceived benefits of such an operation include energy and cost savings due to a reduced hoisting load, a reduced footprint of surface operations, and using material for backfill that has not been contaminated by process chemicals. Progress in the South African mining industry in this area has however been below expectation, and opportunities for underground processing in deep, narrow reef operations were therefore explored by an Excel-based simulation with sensor-based sorting (SBS) as concentration technology. Various PGM mining scenarios incorporating factors such as the mining rate, depth of operation, and effects of dilution and particle size on the metallurgical efficiency, were compared. Whilst these initial results can be regarded as indicative only, they have shown that the economics of such an operation are driven by selective mining at significantly higher rates than achievable with conventional methods. Also, the cost of preparing, conveying and placing rock backfill will need to be lower than that of hoisting waste and depositing it on a surface dump. Another aspect to be addressed is whether ore sorting machines would be able to operate under harsh conditions underground and what provision would need to be made to ensure their efficient operation. Further investigations should focus on refining costs, incorporating environmental considerations in the modelling of economics and sustainability, and compare greenfields with brownfield scenarios. Keywords: Ore sorting, hoisting, backfill, mining rate, economics simulation

Jan 1, 2020

By K. Forsberg, Ş. Kaya, C. Dittrich, M. Svärd, E. M. Peters

Scandium can be recovered from waste streams of other metallurgical processes such as red mud from the Bayer process and titanium dioxide acid waste. This is accomplished by an integrated process comprising leaching using acidic media, solvent extraction using organic solvents and stripping of Sc from the organic phase using NH4F solutions. The precipitation of scandium as (NH4)3ScF6 from NH4F strip liquors has been demonstrated at lab-scale with recoveries and purities greater than 98% and 98.3%, respectively. It is desired to assess the possibility of recovering the solvents for re-use in the process to improve its economy and environmental friendliness. Investigations have been conducted to recover alcohol by simple distillation from strip liquor-alcohol mixtures containing about 50 v/v% alcohol. The mixtures were obtained after anti-solvent precipitation of (NH4)3ScF6 using an alcohol to strip liquor volumetric ratio of 1:1. The starting strip liquor contained about 2000 mg/L scandium in 3 mol/L NH4F solution. In the recovery of methanol, the first distillate product collected had a purity of about 87 v/v% and this decreased slightly with time over two hours. The methanol distillate collected in the first 30 minutes with a purity of ca. 85 v/v% was re-used in anti-solvent crystallisation of (NH4)3ScF6 from the initial strip liquor, and the scandium recovery attained was about 98.6 w/w%, almost similar to that of 99.2 w/w% obtained using 100 v/v% methanol. For ethanol recovery, the first distillate product collected was approx. 84 v/v% pure and the distillate collected in the first 30 minutes with a purity of about 75 v/v% achieved a scandium recovery of about 97.2 w/w% in comparison to 98.5 w/w% obtained using 100 v/v% ethanol during anti-solvent crystallisation. Keywords: Alcohol recovery, methanol, ethanol, anti-solvent crystallisation, (NH4)3ScF6

Jan 1, 2020

Colloquium.' 28 Mei 1980: Spesialiste-Afdeling: Materiaalingeni eurswese Universiteit van Pretoria Materiaalseleksie - Deel II: Keuse en Aanwending van Laelegeringstale Plek.' Onderwerp.' Rapporteur: Professor R. J. Dippenaar Die tweede colloquium van die spesialiste-afdeling van die SAIMM is op 28 Mei 1980 by die Universiteit van Pretoria gehou en is deur sowat 60 mense bygewoon. Dr. J. P. Rugo tree as voorsitter op en heet al die aanwesiges welkom en stel elke spreker om die beurt aan die vergadering voor.

Jan 1, 1980

By S. Curry

The Objana Cement Plant is located in central Nigeria, approximately 200km south of capital city Abuja (figure 1). It is the second largest cement plant in Africa, and the fifth largest in the world [1]. The selected mining location is unique as it has all the major raw materials (except gypsum) in close proximity. This includes limestone, clay, marl, laterite soil, and laterite iron. [ ] The plant has a capacity of 5 million metric tones per year (~15,000 tones per day). A 135 megawatt gas-fired power plant, with 90 km of natural gas pipeline, was constructed to power the plant. The total project cost is approximately 1.2 billion US dollars. The lifeline of the plant is two overland conveys totalling 7.7km in length. The first 800m conveyor is relatively mundane. The second conveyor however, is unlike any other troughed belt conveyor in the world. It 6.9km length transports 2,400 T/H and operates at 5.0 m/s. Its ?snake? profile consists of 11 vertical cuvees, and four horizontal curves. The last of which is 2,000m in radius, has a length of 2.2km, and is located at the high tension head end of the conveyor. Although these specifications are noteworthy, the unique feature of this system is that it is entirely elevated from head to tail using a triangulated truss gantry structure (figure 2).

Jan 1, 2008

The 99th Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room, Transvaal Automobile Club, 60 5th Street, Lower Houghton, Johannesburg on Wednesday, 14th August, 1996. Obituaries The President announced the death, during the year, of the following members: Life Fellows H.L. Munro, H.S. Simpson, P.L. Ward Fellows I.M. Hossy, A.E. O'Meara Retired Fellows E.A. Arvidson, R.F. Bourne, F. Hawke, W. Lloyd, J.M. Meyer Members J. Allen, P.A. Boardman, L.M. Jacobs, G.F. Marx, G.D. Perry, R.W. Spraggs Retired Member M. Milner Associate I. Pieterse. In memory of the deceased and in sympathy with the bereaved, all rose and observed a moment of silence.

Jan 1, 1996

By T. A. Silva, A. C. Bragança

Lime has been added to the iron ore slurry transported by the Samarco pipeline since its operation start-up in 1977.Initially, internal corrosion was the main concern therefore the reagent was used only for pH correction. Over the last ten years, though, transport of more complex slurries demanded a significantly higher dosage of lime to guarantee adequate rheology control. Several other reagents have been tested for the same purpose yet none has proven to be as effective regarding technical performance, environmental impact and cost. However, an alternative was sought so that the slurry rheology could still be controlled in case lime addition became impracticable. The objective of this paper is to present a technical solution for this matter, which takes into account environmental aspects. It consists of adding soda for pH correction and an organic coagulant as a rheology modifier. The latter is a quaternary ammonium salt which affected the slurry transport properties in the same manner as lime when tested in a laboratory. It showed no plug formation and allowed solid particles to settle, forming a loose sediment after rest. These results indicate a low probability of plug occurrence in the pipeline and the formation of a readily reslurryable sediment upon shutdown of the pumping system. Industrial tests should be performed in order to validate the laboratory results.

Jan 1, 2007

By Y. J. F. Haven, G. H. J. Kitson, D. G. Beadle

I have read this paper with considerable interest. By using an automatic instrument to assess the dust samples taken in South African collieries, the authors are ahead of the gold mining industry, which still uses the laborious method of microscopic assessment, with its limited accuracy, of the half-a-million dust samples taken each year. As the authors state, the result obtained from the photoelectric assessment of the samples is approximately proportional to the surface area of the respirable dust. However, modern theory is that, in assessing coal dust, it is the respirable mass which is important in determining the danger to health. Thus Table II of their paper is of considerable value in showing the relationship between the P.E.R. value and the mass concentration measurement. Unfortunately this table only gives the mean relationship. The important point is to know the scatter around this mean. If the scatter is small, then this mean value (for different operations) would have considerable value in converting from respirable surface area to respirable mass, but if the scatter is large, then such a conversion, using a fixed factor, will have little value. In the text the authors mention the range of values as being between 3 to 24, but without a statement on the number of samples used to determine this range and their distribution, this is a rather nebulous statement. I hope, in their reply, that the authors will give, in statistical terms, some statement on the overall correlation between these two parameters. I might add that at present a member of my staff is working on similar relationships for dust samples taken in gold mines. Another factor which may well be most important in determining the danger of dust levels in coal mines is the composition of the dust, specifically its quartz content. I understand that the authors have some information on this point, and to make their results of greater value in International comparisons of dust levels and the concomitant development of pneumoconiosis, it will be extremely useful if they could place this information on record. Even though, as I have said above, modern theory postulates that respirable mass is a better parameter to use than respirable surface area, the problem remains of how to measure this parameter with short time sampling, which, as the authors point out, is their preferred strategy for dust sampling and dust control. I know of no easily portable instrument, independent of external power supplies, which can, in 5 to 10 minutes, collect sufficient dust to enable it to be weighed accurately. Thus the authors' implied intention of continuing to sample by their present techniques and using their present parameter to report the results is, in my opinion, an entirely valid decision.

Jan 10, 1968

By K. Premlall, R. M. Dire, H. Bissett, D. Delport

Tungsten carbide is a fine grey powder. It can be formed into shapes by compacting with the addition of a binder. Spherical particles are generally preferred in additive manufacturing as they pack together more efficiently than non-spherical particles, promoting a uniform powder bed density, better flowability, and elimination of internal cavities and fractures, resulting in a better quality of final product. The particle shape of powders can be transformed into spherical through the process of spheroidization. However, due to its high melting point, tungsten carbide could be difficult to spheroidize. Tungsten carbide was spheroidized using an inductively coupled radio frequency plasma at various plate powers between 9 and 15 kW. The influence of additional H2 in the sheath gas on the chemical composition of the tungsten carbide product was also investigated by means of XRD, which indicated that WC is converted to W2C at higher H2 concentrations. Optical analysis of SEM micrographs indicated that the spheroidization ratio increased with increased plasma energy.

Apr 1, 2021

Book Reviews Linari-Linholm, A. A. Occurrence, mining and recovery of diamonds.Diamond Promotion Services (P.O. Box 62349, Marshalltown, Transvaal). 1974. Rl,OO. Metal Statistics 1962-1972. Metallgesellschaft Aktiengesellschaft. 60th Edition. Frankfurt am Main 1973. 328 pages. Published by Metallgesellschaft A.G., 6000 Frankfurt am Main, Reuterweg 14, Post Box 3724, Western Germany. Symposium on underground mining equipment maintenance~1973. Institution of Mining Engineers, and Association of Mining Electrical and Mechanical Engineers. Colloquium and general meeting A General Meeting and Colloquium on 'Motivation and productivity in the mining industry' was held on May 22nd, 1974, at Kelvin House, Johannesburg. Mr P. W. J. van Rensburg (President) was in the chair. The Colloquium was attended by 170 delegates and was opened by the President at 09h25. Minutes

Jan 8, 1974

By C. Fiore

The annual general meeting of the branch was held in the Witbank Golf Club on Thursday, 28th August, 1969 at 5:00 p.m.

Nov 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.

By K. R. Vost

Variation in air temperature in a cross-section of an underground airway by K. R. VOST, B.Sc. (Glas.), M.Sc. (N.S.W.) (Visitor) Measurements of air temperatures in underground airways are normally made at only one point in a cross-section, and the air tem peratures at other points in the cross-section are assumed not to differ significantly from this. This paper discusses measurements made at a number of points in fifty crosssections in airways with different air velocities and wetness of floor. These measurements show that significant variations of air temperature can occur in a given cross-section at a given time. The effects of such variations on the accuracy of measurement of rises in air temperature as air passes along an airway are discussed. The importance of considering experimental error in the measured rises in air temperature when attempting to validate theoretical and empirical methods of predicting such rises is also discussed.

Jan 7, 1976

By A. O. Filmer

An account is given of a study on the non-oxidative dissolution in aqueous acidic solutions of nickel sulphides of different stoichiometric composition, in which a rotating ring-disc electrode was used. The rate of dissolution was found to depend on the potential of the sulphide and the nickel-to-sulphur stoichiometric ratio. A maximum rate for the dissolution of nickel from nickel sulphides containing an excess of nickel was recorded at potentials around -0,2 to -O,3V. The rate decreased markedly at more anodic potentials. For nickel-deficient nickel sulphides, the nonoxidative dissolution rate increased with a cathodic shift in potential. Under open-circuit conditions, a nickel sulphide of a composition approximating Ni ,S. reacted most rapidly. The dissolution rate was controlled by either a chemical or an electrochemical reaction at the electrode surface, had an activation energy of between 50 and 65 kJ.mol-1, and was independent of stirring speed.

Jan 1, 1980

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 B. E. Protheroe, C. Allen, A. Ball

The results of laboratory abrasive and abrasive-corrosive tests carried out on a range of carbon, Iowalloy, and stainless steels are compared with underground tests conducted on similar materials on prototype shaker conveyors carrying gold-bearing quartzitic rock. The dry-abrasion resistance of all the steels was found to be better than that of mild steel. When the added effect of corrosion was tested, the stainless steels proved to be much superior to proprietary abrasion-resistant alloys both in the laboratory and underground. The ferritic stainless grades were shown to be superior on the basis of cost per unit of volume lost. This investigation has shown that laboratory tests on materials can provide valuable information on their possible performance in situ, and can thus be used to replace lengthy experiments on site.

Jan 1, 1981

H. W. Glen (ed.). Proceedings of Asbestos Symposium, Johannesburg, South, Africa, 3rd-7th, October, 1977. Randburg, National Institute for Metallurgy, 1978. 158 pp. (Copies obtainable from the Department of Mines, P.O. Box 4584, Johannesburg, 2000 South Africa.) This Symposium, which concentrated on the theme of dose-response relationships for asbestos-related diseases, was attended by an internationally representative group of experts in this field. Bulk solids The Powder Advisory Centre announces its third annual International Conference on Bulk Solids Swrage, Handling and Flow, to be held at the Holiday Inn, Liverpool, on 7th to 9th November, 1978. This sequel to the extremely successful November '76 Stratford and November '77 Nottingham Conferences is again to be co-sponsored by a number of internationally acknowledged professional societies, including the Institute of Materials Handling (through its Bulk Solids Panel), the Institution of Production Engineers, and the American Society of Mechanical Engineers (through its Materials Handling Engineering Division). NIM reports Report no. 1943 A review of the literature on the separation and determination of rare-earth elements. (23rd Mar., 1978.) Report no. 1947 The cation- and anion-exchange behaviour of various base-metal chlorides in polar organic solvents. (lOth Mar., 1978.) Report no. 1948 The measurement of trace amounts of gold in solution by atomic-absorption spectrophotometry and carbon-rod atomization. (28th Feb., 1978.) Report no. 1949 The kinetics of the leaching of zinc sulphide concentrates in acidic solutions containing ferric sulphate. (23rd Mar., 1978.) Report no. 1950 Factors affecting the carbon contents of alloys formed during the prereduction of chromite ores. (31st Mar., 1978.) Report no. 1952 The effect of slag composition on copper losses to silicasaturated iron silicate slags. (31st Mar., 1978.) Report no. 1953 A fundamental investigation into the depression of copper-activated sphalerite. (28th Apr., 1978.) Report no. 1956 An improved ion-exchange separation of rare-earth elements for spectrographic analysis. (10th Mar., 1978.) Report no. 1960 The recovery of ferrochromium from furnace slags and related products. (20th Aug., 1976; declassified 31st Mar., 1978.) Process instrumentation The National Institute for Metallurgy and the South African Institute of Measurement and Control are organizing a symposium that will draw the attention of researchers and industrial workers to the importance of metallurgical process instrumentation.

Jan 1, 1978