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By A. J. S. Spearingt

The hydraulic transportation of relatively dense slurries for backfill purposes is typically carried through vertical and horizontal pipelines under gravity. Wear in backfill pipelines has become such a major problem that it is now one of the main reasons for the relatively slow build-up of placed backfill in spite of encouraging performance results in the gold-mining industry. This paper describes tests on pipeline wear that were carried out on classified tailings from the backfill plant at Vaal Reefs East. The testwork was carried out under various conditions of slurry relative density, slurry velocity, and pipeline diameter. Empirical relationships are presented for each transportation and pipeline parameter evaluated and, finally, overall relationships between pipeline conditions and transportation parameters are proposed.

Jan 1, 1992

By L. M. Falcon

Cassiterite is considered to be the only economically significant tin mineral in the earth's crust. In its purest form, cassiterite contains 76 per cent tin. The mineral is hard and heavy but also extremely brittle. and is therefore ideally suited to gravity recovery techniques. Cassiterite deposits can be categorized into two main types, i.e. alluvial or 'soft' rock deposits, and 'hard' rock deposits. The former are relatively simple to upgrade owing to their relatively coarse nature and their high degree of liberation. Hard-rock deposits, on the other hand, require considerably more sophisticated gravity methods to achieve the required degree of beneficiation. Various types of gravity recovery devices, both old and new, are described, and their respective roles in the flowsheets used are illustrated.

Jan 1, 1982

The 96th Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room of the Transvaal Automobile Club in Johannesburg on Wednesday, 11th August, 1993. OBITUARIES The President announced the deaths of the following members of the Institute during the past year. Life Fellow E.F. Laschinger. Other Members R.K. Boright, J.S. Jacobi, R.D. Power, J.H. Cannon, C.J. du Plooy, L.B. Mcrae, C.P. Rossouw, A.L. Sillars, A.W. Heugh, R.K. Briggs, P.J. Stark, and C.S. Stott. As a mark of respect to the memory of the deceased and in sympathy with the bereaved, all rose and observed a moment of silence.

Jan 1, 1993

By R. G. B. Pickering, H. H. Haase

CONTRIBUTION BY D. O'CONNOR Mechanical extraction of rock has been a goal sought after for some decades in the South African gold-mining industry. There are factors distinct from the mode of mechanical extraction that may have considerable influence on its prospects for extensive adoption; the rockburst factor is one of these. REPLY BY H.H. HAASE AND R.G.B PICKERING We agree with Professor O'Connor that, in conventional gold-mining operations, a disproportionate number of seismic events occur in the period immediately following a blast; rockburst activity follows the same pattern, and it has been calculated that, if the rockburst peak were spread evenly across the day, the rockburst exposure of stope workers would nearly double.

Jan 1, 1992

By Johanna van Deventer, Sean Scott, Rene du Preez, Steven R. Izatt

In order to meet the stringent specifications associated with the production of LME Grade A cobalt cathode, producers need to ensure that a number of impurities, including Cd, are removed from the advance electrolyte to ppb levels (~0.1 mg/L). Conventional options include ion exchange using amino methyl phosphonic acid resin and solvent extraction using D2EHPA. More recently a Cd-selective resin, employing Molecular Recognition Technology (MRT), became available from IBC Technologies, Inc. These three potential unit operations were evaluated in parallel at Mintek. MRT was identified as the most technically feasible option. Results obtained on a cobalt advance electrolyte, containing 55 g/L Co, 6 mg/L Cd and 60 g/L Na2SO4, are presented in this paper.

Jan 1, 2007

By M. B. Cortie

An account is given of the development of ferritic stainless steels since their discovery in the early years of this century. The alloys became very widely used in the 1950s, the market during that decade being driven strongly by a demand for automobile trim made of ferritic stainless steel. The production of ferritic stainless steel declined as a proportion of the total at the end of the 1950s as consumer preferences changed. However, the market is now growing strongly again, this time driven by a demand for oxidation-resistant alloys for motor-vehicle exhaust systems. The tonnages produced, applications, and market shares of the various alloys are discussed and compared. Trends in world stainless-steel production, product forms, technological development, and usage are examined.

Jan 1, 1993

By H. M. Friede

A short survey is given of the Iron Age smelting sites and smelting furnaces that have been found in South Africa. An attempt is made to classify South African smelting furnaces by the inclusion of functional characteristics such as the numbers and positions of tuyeres. An affinity is suggested between the Venda (eastern Transvaal) type of furnace and an East African type. The principles of the smelting process in South African Iron Age furnaces and the characteristics of the smelting products are discussed. Results of metallographic and chemical analyses of 19 iron specimens found at South African sites are given and compared with those from sites in Zimbabwe-Rhodesia, Mocambique, and Nigeria. The carburization and steeling of iron during primitive smelting and forging are discussed.

Jan 1, 1979

By J. D. Salter

Most diamonds are liberated from their ores by crushing. Diamond and other coarse grained mineral ores require carefully optimised crushing circuits. Recent advances in computer technology have made possible the on-line capture of crushing plant performance data and, hence, the accurate empirical modelling of the crushing process. Such models are used in simulation studies to determine the optimum operating conditions for a given plant. A system is described which allows operating data from mineral treatment processes to be logged. Up to 16 channels of data may be recorded simultaneously at sampling rates in the kiloHertz range per channel. A data storage and analysis procedure is described which allows the system to make full use of its sampling capabilities.

Jan 1, 1987

By M. Moys

The use of temperature measurements for unusual applications in the analysis and control of column flotation and milling is discussed. This is followed by a review of some of the authors current research in the application of the discrete element method to the modelling of particulate processes, specifically milling, fluidized beds and chute flow.

Jan 1, 2005

The Institute has set important objectives for 1988 to make the Institute still more purposeful. Precious metals The Second International Symposium on Mining, Extraction, and Processing of Precious Metals will be held in Las Vegas, Nevada, USA, during the 118th TMSAIME Annual Meeting in March 1989. The First International Symposium on Precious Metals.

Jan 1, 1987

By G. F. Balderson

In response to the written contribution made by G. J. C. Young to the above paper, I would like to make the following points. Paragraph 1 The build-up of oxidized coatings on cone surfaces has not been a problem in other applications similar to that at President Steyn. The following companies have commented.

Jan 1, 1982

By A. A. Hazell

Mine management by objectives by A. A. Hazel Published in the Journal, September 1972 DISCUSSION H. H. McGREGOR Mr Hazell is to be complimented on a thoroughly down to earth analysis of the uses ot which work study can be put and the benefits of properly applying it in the management of underground production.

Jan 9, 2007

Visit to the Datsun Nissan Company's body pressing and assembly plant at Rosslyn, Pretoria, and the Claremont-Danville Tunnel on 27th February, 1970. The excursion arranged for the 27th February to the Datsun Nissan motor car assembly plant at Rosslyn, near Pretoria, in the morning and the Claremont-Danville tunnel in the afternoon was well supported by some 43 members. The visitors were met at the factory by Mr Rademeyer, the Industrial Relations Manager, and members of his staff and were taken to the artisan training centre for light refreshments. There is a well-equipped training section with an air-conditioned lecture hall; we were told that such training facilities were important because of the cosmopolitan nature of the artisan staff. The visitors were divided into small parties and taken to the tool die and jig-making section, which is perhaps the key department for a factory of this nature. There the many dies for the presses in the body pressing section, as well as the complicated jigs for body welding are made. The technique for making the castings for the dies is interesting. A polystyrene model of the casting is embedded in moulding sand. In a neighbouring foundry molten metal is pressed into the headers and burns away the polystyrene, which leaves no residue, and this exactly fills the space occupied by the model. This rough casting is then machined in large copying machines (costing as much as Rl80 000). An exact plastic model of the surface of the pressing required, set up in juxtaposition to this casting is traversed by a master stylus which operates the slave milling cutter, thereby machining the surface to close tolerances. The machined casting is cleaned up by hand and finally finished in large spotting machines, using a blue dye to show up high spots, to the fine degree of accuracy required. The body pressing section was next visited. There the large number of pressed parts which make up a vehicle body are pressed out of special deep drawing steel plate. Some of the largest presses were capable of applying a pressure of 1 200 tons and cost as much as Rl85 000 each. The visitors then followed through to the assembly section where jigs are used to hold together the many pressings, which are then spot welded into body frames. The frames go to an assembly line where they are finished to the stage for painting. The continuous crawl painting assembly line carries the frames through all the stages of prime coating with zinc phosphate sprayed on in a tunnel, followed by immersion of the lower parts in a priming bath, then drying and spray painting and baking in tunnels. The body frames, after painting, join another assembly line, where the doors, upholstery and many fittings are attached. After this stage the completed bodies are lowered onto and attached to the chassis units which are largely assembled from imported parts (engines, transmission units, etc.). From the end of the line the completed cars are driven off to the trial track and then pass through a tunnel with powerful water sprays to detect leaks in the body work. The proportion of locally made parts is just on 45 per cent. An interesting aspect of the assembly organization is that, of the 140 or 160 cars completed each day there may be included some of each of the Datsun model as well as some Renault and Alfa Romeo models models which are assembled by this company. The change from one model to another several times a day does not present any difficulty to the organization. Each section of the assembly plant 'buys' the units from the preceeding section and 'sells' to the succeeding section. This means that the responsibility of each section ends when the unit is sold to the next section. The cost of repairing any faults found subsequently is charged to the section where it is found, which puts a powerful emphasis on meticulous inspections between sections to safeguard their costs. After the tour the parties assembled at the lecture hall where a lavish cold buffet luncheon was provided by the company. After luncheon Mr A. R. C. Fowler, on behalf of the Institute, thanked the Managing Director, Mr W. J. Wilson and his staff for this most interesting and well organized visit. The party then left for the Claremont-Danville tunnel. The tunnel is being driven by General Mining Federale Kontrakteurs through the Daspoort Range, Pretoria, to link the suburbs of Danville, near Iscor, and Claremont, which at present can only be reached by a nine mile detour. It is estimated that some 6000 vehicles per day will use the tunnel. Before entering the tunnel a short talk was given by Mr Ross who is in charge of operations. He called on various officials and staff of the Consulting Engineering firm, Basil Read (Pty.) Ltd., to describe the tunnel and

Colloquium and General Meeting were held at Kelvin House on 19th May, 1971, the theme being 'Modern trends in coal mining practice.' Mr V. C. Robinson (President) was in the Chair. The Colloquium was attended by 205 delegates and was opened by the President at 9 a.m. OBITUARY The President: 'It is my sad duty to announce the death of C. C. Cullen, Fellow, who joined the Institute in 1946 and passed away on 15th March, 1971. As a mark of respect to the memory of the deceased and in sympathy with the bereaved I would ask you all to rise and observe a few moments silence'. ELECTION OF SCRUTINEERS The President: 'In terms of Clause 9.4 of the By-Laws I now call for the nomination of seven Corporate Members to act as scrutineers of the ballot for Council'. Messrs V. C. Robinson, Prof D. D. Howat, Dr J P Hugo, D. G. Maxwell, J. K. E. Douglas, R. J. Adamson and P. Lambooy were nominated by P. W. J. van Rensburg and seconded by P. A. von Wietligh. The President: 'Are there any further nominations? If not I declare these gentlemen elected.' MEMBERSHIP The President: 'I have much pleasure in announcing that the names of 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: Douglas Edward King, Bryan Rudolph Scott, James Gregor Phimister, Anthony David Walters. Graduates: Cornelius Johann Muller, Marthinus Stephanus Mulder. Associates: John George Everson, Colin Robert Llewellyn Davies. Students: Francois George Enslin Beetge, Ewald Boshoff, Christiaan J. Cloete, Christopher John Davies, Cameron George Elvin, Kenneth Eric Field, Johannes Louis Fourie, Hans Gert Gastrow, Peter John Ledger, James Robert William Lindsay, Kynaston Lloyd McDonald, Richard Peter Mohring, Arthur Leslie Painting, Matthias Arthur Pascall, Ian Neil Sinclair, Donald Allan James Ross-Watt. MEMBERS TRANSFERRED TO A HIGHER GRADE From Member to Fellow: Peter Norman Roberts. From Associate to Graduate: Alfred Eric WaIter Fletcher. From Student to Graduate: Wilfried Pierre de Villiers, Edward Emile Eichenberger, William Alan Nairn, Lodewyk Johannes de Jager, Colin Henry Obray, John Grenig Rees. COLLOQUIUM The President opened the proceedings and introduced Mr N. W. S. Schumann as the overall chairman for the day. The following papers and contributions were presented: FIRST SESSION: Chairman R. C. J. GOODE. Paper: 'Problems encountered in the operation of a new colliery' by P. M. C. Wilson and A. A. Oakes. Contributors: D. J. Moloney, G. R. Canny, I. G. Evans, R. B. MacGillivray, Dr F. G. J. de Jager, M. J. Deats, and N. Zolezzi. R. B. MacGillivray Mr President and gentlemen, I would like to congratulate the authors on presenting a most interesting paper on a very important subject. After several attempts at finding suitable reserves to extend the life of Welgedacht Exploration Company's Utrecht Colliery a block of coal rights was acquired south west of the town of Utrecht. A study of these reserves showed that they would enable a satisfactory return on capital invested to be achieved. It was decided therefore to open up what is now called the Zimbutu section of Welgedacht Exploration Company, to produce 41 000 metric tons of coal per month. The decision to open this section was taken in August, 1968 and due to certain allocation requirements it was necessary to bring it into production by the 1st of January, 1970. Fortunately a fair amount of statistical data had been collected prior to August, 1968 from the old Utrecht Colliery in anticipation of opening a mine and a fairly detailed rechnical report had been prepared. As a result the dead line was only missed by four days. Main features of the Design A feasibility study was carried out on three possible shaft positions and the final position was selected from these three on economic grounds. As the coal seam at the selected shaft position was only 21 metres below the surface it was decided to sink two twin incline shafts to enable rapid establishment of through ventilation and alternative hauling arrangements for quick development. This also allowed the final vertical ventilation shaft to be placed at some distance away to avoid the nuisance of fan noise. Second outlet requirements are also very well met by these twin inclines. Again on the basis of economics and also due to the uncertainty of roof conditions it was decided to use hand loading methods underground. However, to allow for future possible conversion to mechanised loading, should this become economical through rising wages, a conveyor belt was installed in the hauling shaft. This conveyor belt is fed from an endless rope haulage in the east companion by means of tipplers, a bin and a feeder. The main development heading was left clear for the future installation of a conveyor belt which would afford easy conversion to mechanisation.

By J. W. Latilla, J. J. van Wijk

In late 1997 a request was received to assist with determining the powered support unit (shield) load capacities for the planned 2 seam short wall. This project had a number of aspects which made it attractive to utilize numerical modelling in conjunction with other more conventional design tools in the design of the shields. Amongst these were: The 2 seam panels were to be laid out about 25 m below the previously short walled 4 seam, the 4 seam had in turn been over-mined by the 5 seam long wall, the proposed face height of the 2 seam short wall was 5.5 m while the 4 seam had been mined at 4 m. The top seam in the area (5 seam) had been mined at between 1.5 and 2.2 m high, the face conditions with about 95 m of broken material applying dead weight loading to the 2 to 4 seam inter-burden septum were hard to predict and cyclical loading due to the presence of strong sandstone bands in the 2 to 4 seam inter-burden. The basic thrust of the study was to take the known, and successful, situation (4 seam short wall) and carry out comparative modelling to enable prediction of likely 2 seam conditions. Some two dimensional aspects studied were: 5 m goaf hanging up behind shields, stresses in beams to determine likely first goaf roof span, stresses in cantilever beams to asses cyclical loading due to sandstone bands in the interburden being loaded by the overlying goaf and stresses on chain and crush pillars adjacent to the goaf edge. Three dimensional aspects that were investigated included: Load distribution along face for close goafing and 5 m goaf hang-up and load in a 1 m wide rib modelled in the position of the powered support units. From the modelling it was possible to determine the optimal shield leg capacity of the new 2 seam equipment. These outputs were used when drawing up the technical specifications for manufacture of the new equipment. The face was successfully commissioned in August 2002. Fin 1997, requête fut faite pour aider à la détermination des capacités de charge pour l’unité de soutènement mécanisée (bouclier) pour la couche 2 courte taille en projet. Certains aspects de ce projet le rendaient intéressant pour utiliser la modélisation numérique en même temps que d’autres méthodes conventionnelles pour la conception des boucliers. Parmi ces aspects se trouvaient : Les panneaux de la couche 2 devaient être placés environ 25 m au dessous de la couche 4 courte taille ; la couche 4 avait été remplacée par la couche 5 longue taille ; la hauteur de taille proposée pour la couche 2 courte taille était 5.5 m, tandis que la couche 4 avait été exploitée à 4 m. La couche supérieure de la région (couche 5) avait été exploitée entre 1.5 et 2.2 m de hauteur ; il était difficile de prédire les conditions de taille, avec environ 95m de matériaux cassés ajoutant une charge morte à la plaque de séparation entre les couches 2 et 4 et un chargement cyclique causé par des bandes de grès dans l’entre-fardeau 2-4. L’idée principale de l’étude fut de prendre la situation connue et réussie (couche 4 courte taille) et de faire une modélisation comparative pour prédire les conditions probables de la couche 2. Certains des aspects à double dimension qui furent étudiés étaient : Un accrochage de remblai de 5m derrière les boucliers ; contraintes dans les poutres pour déterminer le premier intervalle probable entre remblai et toit ; contraintes dans les poutres en porte-à-faux pour évaluer le chargement cyclique causé par les bandes de grès dans l’entre-fardeau qui est accablé par le remblai et les contraintes sur les piliers par chaîne et d’écrasement adjacents au bord du remblai. Aspects à trois dimensions qui furent étudiés : Distribution de la charge le long de la taille pour les remblais proches et l’accrochage de remblai de 5 m et la charge dans une nervure de 1 m de large modelée dans la position des unités de soutènement mécanisées. La modélisation a permis de déterminer la capacité de portée optimale du bouclier du dispositif nouveau pour la couche 2. Ces résultats furent utilisés pour dresser les spécifications techniques pour la fabrication de l’équipement nouveau. La taille fut commissionnée avec succès en août

Jan 1, 2003

A manual on mines rescue, safety and gas detection, by J. Strang and P. Mackenzie-Wood. Australia, Austcue, US$25. (Available through Hampo Systems (Pty) Ltd. Reviewer: W. Holding. The book had its origins in a set of notes used by one of the authors for training purposes at the Southern Mines Rescue Station in New South Wales

Jan 1, 1987

Tunnel Construction 90. London, Institution of Mining and Metallurgy, 1990. Reviewer: J.A. Cruise This is the published volume of papers presented at the Tunnel Construction 90 Conference, which was held in London in April 1990 under the auspices of The Institute of Mining and Metallurgy. Twenty papers are presented and their titles are listed below.

Jan 1, 1991

By S. Z. Shkundin

An evaluation of the accuracy of tachometric and hot-wire anemometers in mine workings and gas-media ducts is given. The acoustic means of gas flow rates measurement is considered with particular reference to the equations of acoustic waves propagation in aerodynamic fields. The paper defines how it is possible to minimize the error of integrating acoustic anemometers.

Sep 1, 2001

By J. D. de V. Louw

Introduction Zircon is a natural occurring mineral and may exhibit natural low level radioactivity. It contains trace levels (90 to120 pCi/g and 110 to 115 pCi/g respectively or 3.3 to 4.4Bq/g and 4.1 to 4.3 Bq/g) of naturally occurring radioactive uranium and thorium. This mineral is often found in a suiteof minerals (rutile, ilmenite and monazite) Due to the overlap in physical properties of monazite (containing 4–7% thorium) with some of the zircon (slight magnetic susceptibility) it often contaminates the zircon, adding to the levels of thorium in the product. Hazards associated with the products from zircon and its processing is inhalation of respirable dust (generated by milling) containing radioactive uranium and thorium which may cause cancer of the lungs. Legislature regulates the transport, use, workplace environment exposure and storage of radioactive material. In America the general regulation for the unlicensed use of low levels of radioactive materials limits the concentration to 500 ppm (U plus Th). Europe (IAEA) specifies a limit of10 Bg/g (Bequerels per gram) on the parents for transport only which is a higher level of U+Th. Companies selling into these markets need to comply with these regulations and certification is therefore required, not only of the major constituents determining the price, but of the U and Th levels as well. Exceeding the limits for U and Th may result in material being returned to the country of origin. However, for the analyst the requirement is to analyse for these elements throughout the production process as well as the analysis of the ‘tails’ that is returned to the mine area. This requires a wide range of concentration to be analysed. Methods of analysis A wide variety of methods exist for the analysis of U and Th in a range of matrices. (Table I) All these methods have been used with varying degrees of success in terms of accuracy. Overall precision for the different techniques varies from 5 to 25% relative. Time to produce results from these methods vary from a few minutes to several days. The Production Chemist is expected to produce between5 and 10 analyses per hour for process control purposes. A suitable technique that fits this requirement is X-Ray Fluorescence. Both Wavelength Dispersive (WDXRF) and Energy Dispersive X-Ray (EDX) instruments are suitable. X-Ray analysis in general has a few major advantages over competitive techniques. •It is fairly simple to set up and interferences are known and easy to correct •It has multi-element analysis capabilities •Clean spectral lines for U and Th (in zircon specifically) •Uncomplicated and easy to measure background •Low detection limits (3 to 5 ppm) •A very high degree of precision •Sample preparation is uncomplicated and fast (pressed powders and fused beads). In Zircon (ZrSiO4) processed sands the matrix is constant(>99% ZrSiO4) and the background is thus essentially constant. A typical set up for the analysis of U and Th by WDXRFis given below: X-Ray Tube Tungsten (W) Target, 2.5 to 3kW operated at 50mA/50kV Crystal LiF200 (or LIF220 for higher resolution) Analytical Lines (2?)U La1,226.14Th La1,227.47 Detector Scintillation Counter Analysis time, depending on the concentration can vary from as little as 20 seconds up to 5 minutes. Standards As with any other comparative technique XRF analysis relies heavily on the quality of the standards used. Assuming proper set-up and operation of the instrumentation as well as consistent sample preparation, accuracy is determined by the quality of the initial calibration standards. A search for the available zircon certified reference materials (CRMs) shows that there are only a few CRMs

Jan 1, 2003

O.F.S. Branch Proceedings of the Annual General Meeting on Wednesday, 30th July, 1975 The Aromal General Meeting of the Branch was held at the St. Helena Club on Wednesday, 30th July, 1975 at 7.45 p.m. Mr D. A. Smith (Chairman) was in the Chair. There was also present: Professor R. P. Plewman, President of the S.A. Institute of Mining and Metallurgy. Conference on Vacuum Metallurgy The Fifth International Conference on Vacuum Metallurgy is to be held in Munich from 11th to 15th October, 1976. Excavation and tunnelling A conference on 'Rapid Excavation and Tunneling' is to be held in Las Vegas from 14th to 17th June, 1976. Book reviews Mine filling. Queensland (Australia), Mt. Isa Mines, Limited, ] 973. 293 pp. $A20,00 incl. postage. Young, R. S. Cheml:cal phase analysis. London, Charles Griffin, 1974. 126 pp. £4.50. NIM reports Report no. 1714 The efficiency of the fire-assay procedure with nickel sulphide as the collector in the determination of platinum,silver, gold, and iridium. Report no. 1721 A preliminary investigation into the mechanism of depression in the flotation of sulphide minerals at the Prieska Copper Mine. Report no. 1725 The determination of silica in fluorspar by 14 Me V neutron-activation analysis. Report no. 1736 The determination, by atomic- absorption spectrophotometry and liquid extraction, of antimony (parts per million) in ores and concentrates. Report no. 1741 South African costs of equipment for the metall'urgical industry(1975}. Report no. 1744 The refining of the platinum-group metals . Report no. 1746 The determination, by atomic-absorption spectrophotometry, of minor elements in zinc, lead, and copper sulphide concentrates. Report no. 1747 Magnetohydrostatic separation of gold from gravity concentrates. Report no. 1750 A review of the present and future development of sulphur production in South Africa. Report no. 1754 A new three-dimensional anodic electrode for reduced power consumption du,ring the electrowinning of metals. Report no. 139 A preliminary survey of goldrecovery problems arising in the production of pyrite. (9th Feb., 1967, re-issued Jun. 1975.) 16 pp. Report no. 140 A preliminary mineralogical investigation of pyrite from the K imberley and the Main Reefs, VogelstruisbuU Gold Mine. (13th Feb., 1967, re-issued Jut 1975.) 11 pp. Report no. 165 Gold recovery from pyrite flotation mill products by cyanidation. Progress made up to 1st May, 1967. (5th May, 1967, re-issued Jun. 1975.) 8 pp. Report no. 133 Gold recovery by cyanidation from mill products obtained after pyrite flotation. Progress made up to ht July, 1967. (18th Jul., 1967, reissued Jun. 1975.) 14 pp. Report no. 219 A review of some of the mineralogical factors influencing the flotation of pyrite. (29th Nov., 1967 reissued Jun. 1975.) 20 pp. Report no. 278 Gold recovery by cyanidation from mill products obtained after pyrite flotation. (24th Jan., 1968, re-issued Sep. 1975.) 51 pp. Report no. 306 The effect of preaeration on two samples of thickener under flow from the Venterspost Gold Mine. (30th Mar., 1968, re-issued Jul. 1975.) 14 pp. Report no. 317 Results of tests carried out at the Loraine Gold Mine during the period 5th to 7th February, 1968. (21st Mar., 1968, re-issued Jul. 1975.) 11 pp. Report no. 321 Aeration of ore from the Loraine Gold Mine before theaddition of cyanide.(17th Apr., 1968, reissued Jul. 1975.) 30 pp. Report no. 380 The effect of aeration, before cyanidation, of pulps of gold ores containing xanthate. (14th Aug., 1968, re-issued Jul. 1975.) 44 pp.

Jan 10, 1975