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The sulphides can be arranged in a series determined by the relative amounts of ionic and covalent bonding present. This series is similar to the paragenetic series common to most sulphide ore deposits. Investigation of the surface tensions of the corresponding heavy metal iodides by the maximum bubble pressure method throws some light upon this relationship. It is shown that the surface tension of molten iodides decreases as the chemical bonding within them becomes more covalent. These results are interpreted in terms of the constitution of the melts, and are extended to cover the case of sulphides in solution in a silicate melt. It is concluded that sulphides tend to lower the surface tension of silicate melts and that this tendency becomes greater as the bonding within the dissolved sulphide groups becomes more covalent. A possible relationship between this conclusion and the origin of paragenesis in sulphide ore deposits is indicated.INTRODUCTIONIt is well known that the order of deposition, or paragenesis of sulphide minerals is remarkably similar in hypogene ore deposits throughout the world. This widespread similarity points towards the operation of some fundamental process which must be intimately connected with -the genesis of these ores. A correct interpretation and understanding of the causes of paragenesis in sulphide ore deposits would shed much light on the origin of these deposits.In Table 1 a simplified paragenetic series for sulphide minerals is presented. In most cases, only the most important sulphide of any particular element has been included. The object of this procedure is to simplify the following discussion. Furthermore, it should be realized that this series is only a generalization and that exceptions and reversals of position are quite common. Especially does this...

Jan 1, 1956

By Budiselic C, Hefter G

The uptake of gold by activated carbon from acid chloride solutions involves the reduction of gold(IIl) to metallic gold. Deposition occurs only on the surface of the carbon at localized active sites at first, and subsequently at less active areas. The rate of uptake depends on the surface area of activated carbon, which confirms results from a recently published study (de Siegel and Soto, 1984). Increased rates of uptake were observed at higher temperatures and lower chloride concentrations due to the decreased stability of AuCI4-, the major gold(IIl) species present. Recoveries of gold approached 100 per cent for a contact time of 60 minutes at 20°C in a well stirred solution initially 5 ppm in gold(III) and containing 0.5 per cent w/v coconut-shell carbon. The presence of 0.25 Mnitric acid or 100 ppm iron(IIl) had no detectable effect on either rate or efficiency of gold uptake.

Jan 1, 1985

Professor Skeats said: I wish at the ,outset to express my appreciation of the h0!-l0ur conferred on me by my election as President of this Institute for the ensuing year. The selection of a geologist for this position by a body of mining engineers andmetallurgists may be taken as an indication of the recognition that the subject is one which may play a useful part in the great metal industry. Among the records of primitive man the finding of implements of bronze and of iron indicated one of the important, advances made in human civilization, and shows that...

Jan 1, 1924

The Research on Refined Gold Bullions Surface Upgrading

Sep 13, 2010

Investigation on Multicomponent Semi-Autogenous Grinding

Sep 13, 2010

By P Staples, G Lane, S Morrell

The design of semi-autogenous grinding (SAG) mill based comminution circuits for the treatment of competent ores, similar to those at Geita and Boddington, involves the same process of sample selection, test work, data analysis and data modelling/interpretation as that used for 'average' competency ores. However, over the past couple of years a number of issues have arisen that are common to the design of circuits for the comminution of 'highly' competent ores. The impact of these issues on project viability is generally more pronounced when treating hard ores than average to soft ores due to the greater impact on capital and operating costs. The issues encountered have included: standard test procedures have been modified; test equipment has worn or been damaged; different procedures yield different data and varying interpretation; and modelling and empirical calculations have been based on poor benchmarks, or used incorrectly in the case of JKSimMet, yielding misleading outcomes. The purpose of this paper is to present, discuss and clarify some of the issues associated with conducting test work and designing comminution circuits for the treatment of 'highly' competent ores in order to reduce thelevel of conflict arising from interpretation and application of test work data. Specifically, the issues associated with the bond crushing (impact) and rod work indices measurement, the various SAG mill specific energy tests, and the interpretation of the resulting data will be discussed in the context of case studies.

Jan 1, 2009

The effect of conditioning energy input on the metallurgical results of an emulsion flotation process has beenattributed by previous authors to a detergency process.This paper shows that such a process does not explain the data and that an attrition mechanism is more appropriate.

Jan 1, 1970

By Edwards A. B

A table concentrate obtained experimentally by the New Occidental Gold Mines N.L. has unusual interest on account of the presence in it of abundant coated or "black" gold. The concentrate was obtained from ore from the New Cobar mine, Cobar, New South Wales, by feeding the oversize product from a "Dorr Bowl classifier to a Card table.Its assay value was 129 oz. of gold and 52 oz. of silver per ton, yet practically no free gold could be seen on panning.When, however, the concentrate was digested in hydrochloric acid fine rusty gold could be obtained by panning.The following chemical analysis was carried out by the mining company on a similar sample of concentrate.

Jan 1, 1941

By W Zeng, D Walker, D Cai, E Baafi

"The efficiency of the truck-shovel haulage system is significantly influenced by the truck fleet size. A discrete event simulation model with 3D animation has been developed to estimate the productivity of a truck-shovel network system, shovel efficiency, truck cycle time, truck utilisation and the optimal fleet size. The simulation model considers the dynamic variability of traffic conditions and also the truck as an individual entity. The resulting truck cycle time was found to be realistic and thus providing a better tool for strategic mine planning.Citation:Zeng, W, Baafi, E, Walker, D and Cai, D, 2016. A 3D Discrete Event Simulation Model of a Truck-shovel Network System, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 265–273 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

The Bulli and Wongawilli Seams, the two principal sources of coking coal for the Port Kembla steelworks of Australian Iron & Steel Pty. Ltd., vary in rank and in type over the Southern and South Western Coalfields.The Bulli Seam, ranging widely in type, produces coke varying from weak to strong. The Wongawilli Seam, more consistent in type, produces coke of more consistent strength, but considerably less strong than that from the best Bulli Seam coal.Plans of seam variation show the regional trends in rank and type for each seam.The strongest coke is derived from coal containing between 45 and 55 per cent vitrinite, m.m.f. This is obtainable from the Bulli Seam in a zone embracing Bulli and Appin collieries.A satisfactory correlation is achieved between vitrinite content and coke stability and hardness, enabling prediction of coke strength for Southern Coalfield coals.The use of vitrinite reflectance, as an indicator of rank, in addition to type to predict coke strengths is at present hampered by lack of data, particularly in the South Western Coalfield. Nevertheless, data available at present allow the use of both variables and give better correlations with coke strengths than type alone.A spread of comprehensive data across both coalfields will enable advance assessment of cokes produced from coals having known rank and type. Blending to a ranktype specification for optimum coke strengths would allow the best use of the coal reserves of the coalfields.

Jan 1, 1969

In the course of the last twenty eight years the copper lodes of New Caledonia have been periodically worked or abandoned, until quite recently, probably attracted by the higher price of the metal, British capital has again been induced to embark upon the further development of several copper properties, which at present give reasonable promise of becoming regular producers. Owing to its proximity to Australia (only a three day's journey by mail steamer from Sydney) New Caledonia becomes of additional interest to Australian commerce in general, and it is to be hoped that the French Government may see their way before long to make the best of this natural position, to the mutual benefit of both countries concerned.Op till now all copper ores and concentrates which have been shipped from New Caledonia, were treated in Australian smelting works furthermore, Australian mine managers and miners have from time to time been connected with New Caledonian mining ventures, but, unfortunately, it must be said that nearly everyone of them returned to Australia thoroughly disgusted with his experience over there. Even to the casual observer, it is not so very difficult to find a proper explanation for these shortcomings in the peculiar economic conditions of the 'French colony, as many of the objections which have hitherto existed in connection with mining operations, were the direct consequences of a system of colonisation which could not possibly have been productive of better results.

Jan 1, 1901

In presenting this paper the author has in view a twofold purpose. In the first place, it is intended to set forth for the benefit of practical mining men some account of the principles underlying the design of tungsten carbide rock bits in the hope that a knowledge of these principles will assist in the successful application of the bits to mine and quarry drilling. Secondly, by evoking discussion, and even controversy, it is hoped that manufacturers and users of these rock bits will be encouraged to contribute to the general knowledge of a subject which to date has been rather lacking in published literature. The author well appreciates that many of the conclusions drawn in this paper are highly controversial, but if the only result is to call forth contradictory testimony from other workers in this field, at least one of his purposes will have been achieved.An attempt will first be made to set forth and examine those characteristics which go to make up an efficient rock bit, and the main factors affecting these characteristics will be discussed. In a paper of this general nature, consideration of any particular aspect must necessarily be rather brief, and there is little opportunity for detailed presentation of test procedures and data. Thus, it has been found advisable' to confine discussion of some minor points to a simple statement of fact. However, an attempt has been made to support all major conclusions by reference...

Jan 1, 1950

By M Kozikowski

The primary purpose of these investigations is to determine dewatering requirements and likely impacts associated with mining operations. Standard aquifer testing techniques were carried out at multiple locations within the Ord Range near Pardoo, Western Australia. Aquifer properties of an oxidised haematite orebody were calculated from test pumping data conducted in five fully penetrating test bores. Hydraulic properties of the Ridley magnetite orebody were calculated based on short term constant rate pumping tests, and packer tests. Packer tests were conducted in undeveloped and uncased exploration holes and diamond core holes. The new data sheds light on the hydrogeological properties of this previously unexplored region of Western Australia.Aquifer testing procedures for each bore included a preliminary step test followed by a constant rate test. Recovery data were collected in each bore over a period of four to six hours. Prior to testing, background water levels and water samples were collected in a network of monitoring and exploration bores to establish baseline water levels, gradients and water quality. Water quality within the bedrock of the Ord Range varies from 2000 to 5500 mg/L TDS whereas water quality within the alluvial sequence of the De Grey River is highly variable (400 to 2500 mg/L TDS), but is predominantly brackish with some water of potable quality which is used to supply Port Hedland. Test pumping supports the conceptual hydrogeological model that consists of a pod like orebody (aquifer) surrounded by low permeability waste rock (BIF), with very weak hydraulic connection to the adjacent alluvial systems. Calculated hydraulic conductivity from test pumping data across Pardoo ranged from 0.01 to 59 m/d, depending on deposit tested.A groundwater model was used to simulate dewatering required in proposed pits and to estimate the impact of dewatering on the surrounding shallow alluvial aquifers. Test pumping and numerical groundwater flow modelling indicate the proposed below water table pits can be successfully dewatered utilising in pit dewatering production bores. Yields from individual dewatering bores will reduce with time due to the reduction in saturated aquifer thickness.Based on the numerical groundwater modelling and field investigations the likely impacts to the adjacent De Grey River alluvial aquifer system (within the Priority 1 De Grey River Water Reserve) resulting from mining and dewatering activities is considered minimal. Recalibration of the groundwater model will be undertaken once several months of dewatering data are available.The aim of this paper is to present a range of aquifer parameters derived through standard aquifer testing techniques for an area previously unexplored in terms of hydrogeological characteristics. It is the goal of the authors to provide this comparison data set for future work in similar geologic media.

Jan 1, 2009

ALTHOUGH the development of the various flotation processes during the last 8 years has been so revolutionary, this development has been, until recently, entirely confined to the separation of the gangue from the mixed metalliferous sulphides.The desirability of finding some method of separating the independent sulphides from such a miXture, by means of flotation, has long been recognized. ThIS need was emphasized when the slimes resulting from the grinding of Broken Hill sulphide ores were for the first time successfully dealt with by the Mineral Separation Company's process on the Central mine. This process proved the practicability of separating the sulphides of lead and zinc as a mixed concentrate from the gangue present in slime. Although this was a very notable achievement, the process has not been generally used, owing to the mixed lead and zinc concentrates resulting from the treatment being acceptable neither to the zinc nor the lead smelters.Although the introduction of eucalyptus oil in minute quantities as an emulsifying agent has simplified the work of the subsequent tabling of mixed sulphide concentrates, rendering unnecessary the burning off or removal of the oil, there will always be a considerable quantity of slimy product too fine to settle on the moving surface of the concentrating machines, and therefore requiring other means for its division into lead and zinc concentrates.

Jan 1, 1912

By Penrose E. K

With the exception of occasional periods, when up to 80% of oxidized ore was treated, the G.M.K. plant treated all sulphide ore until October, 1939. The treatment was, briefly, as follows:The ore was ground to approximately 17% plus 200 mesh Tyler and agitated in cyanide solution, after straking. After agitation, the pulp passed through two stages of counter-current decantation washing in Dorr thickeners and was filtered once, to complete the precyanidation stage.The precyanide filter cake was repulped with flotation circuit solution and floated in a Denver Sub A flotation machine, consisting of twelve cells. The concentrates were roasted, cyanided and filtered four times before disposal to the' dam. The flotation tailings were thickened to conserve water and pumped away to a separate dam.The average results of flotation operations for the six months before October, 1939, are shown in Table 1.

Jan 1, 1942

By L Kempenaers, T van der Maten, U König, M G. C Zoontjes

Improving liquid blending operations in production plants is of paramount importance in many industries like mining, oils, petrochemicals and food. For accurate blending of different types of process streams, like homogeneous, heterogeneous, cold or hot streams, it is essential that the composition can be accurately monitored in real time. Advances in energy dispersive X-ray fluorescence (EDXRF) technology offers the possibility to apply XRF for online elemental analysis. In this paper we discuss an online EDXRF analyser for accurate blending control in many industries.EDXRF has the advantage that multiple elements can be measured simultaneously over a wide concentration range of wt per cent down to a few mg/kg, for elements between sodium (Na) and americium (Am) in the periodic table. To reach the desired accuracy and precision in an online XRF analyser, it is important to bring a representative and homogeneous sample of the process flow into the optical path of the analyser. The combination of a laminar flow cell design and advanced EDXRF technology leads to low detection limits and high performance. The obtained precision and accuracy allows for much tighter process control. In this paper we present two examples of industrial applications.CITATION:Zoontjes, M G C, van der Maten, T, Kempenaers, L and König, U, 2017. Online X-ray fluorescence spectrometer for accurate monitoring and improving blending sharpness in liquid production processes, in Proceedings Eighth World Conference on Sampling and Blending , pp 235–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By D FitzGerald, S Jakica, R Paterson, J Silic

A new 2.5D airborne electromagnetic (AEM) algorithm has been developed by Intrepid Geophysics and Jovan Silic & Associates. The advantage of 2.5D (2D geology, 3D source) AEM inversion in 3D geological mapping applications and identification of conductive drilling targets, compared to the more commonly used conductivity-depth imaging (CDI) transforms or 1D inversions, are demonstrated using examples from banded iron formations (BIFs) and other geological settings. We show emerging AEM systems are capable of providing estimates of economic rock unit thicknesses, dips and fault definition at an accuracy that mitigates the need for pattern drilling.The 2.5D inversion application used in this work and described in Silic et al (2015) is a substantially changed version of ArjunAir (Wilson, Raiche and Sugeng, 2006), a product of CSIRO/AMIRA project P223F. The changes include a new forward model algorithm and a new inversion solver. The application enables the accurate simulation of 3D source excitation for full domain models inclusive of topography, non-conforming boundaries and very high resistivity contrasts. Solution is accurate for a geoelectrical cross-section, which is relatively constant along a strike length that exceeds the AEM system footprint.The major innovation includes a new inversion solver with adaptive regularisation, which allows the incorporation of a misfit to the reference model and the model smoothness function.Memory usage has been dramatically reduced and is estimated prior to execution. For speed the software has been parallelised using Intel message passing interface (MPI) and can be used on standard computing hardware or computing clusters. Data from survey lines with lengths exceeding 100 km can be inverted on high end laptop computers.We allow flexibility in the selection of components and in the estimation of noise.AEM inversion examples are shown for surveys from BIFs, base metals (volcanogenic massive sulfides) and geological mapping projects and the results are compared with known geology and drilling. We demonstrate the much improved mapping and target definition delivered by this inversion method when compared with the other more common transforms or inversion methods used on these projects.CITATION:Paterson, R, Silic, J, FitzGerald, D and Jakica, S, 2017. High accuracy .D airborne electromagnetic inversion method for banded iron formation and other geological settings, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Pound J. R

THIS mine, which is the property of the S. and M. Syndicate, London, is located at Moina, in North-West Tasmania, 18 miles from Stavertorr railway station and 36 miles from Devonport. There are metalled roads from both of these places, and, althoughhilly, these are good for team or motor traffic. Mails and passengers are provided for by a tri-weekly coach service from Sheffield, a railway town, distant 23 miles. The Moina mining field is situated on a main spur between the Forth and Iris Rivers, andat an elevation ranging from about 500 ft. above sea-level at the Forth River to 2400 ft. at the All Nations mine. The elevation at the mine office of the S. and M. mine is 1900 ft. The average annual rainfall, as recorded for the past eight years, is. 68 in.This inclildes, however, a couple of years during which the rainfall was much above normal, and taken over a longer period 60 in. would be nearer the average.

Jan 1, 1919

By R WOODS

The interaction of, flotation collectors with sulphide mmerals takes place at the solid-solution interface. The electrochemistry of the processes which affect this interface are discussed. The interaction of xanthates with sulphides is an electrochemical process, xanthates being electro-oxidized to chemisorbed xanthate and dixanthogen.The role of oxygen is to provide a cathodic process to allow the anodic oxidation to occur. The hydrophobic condition of the mineral surface is brought about by the presence of the oxidized xanthate species. The action of reagents which can activate or depress the flotation of sulphides is discussed briefly.

Jan 1, 1972

The nature of the specialty glass and ceramic business magnifies the dependency of the ultimate product on the unique properties of their raw materials used to make them. This dependency has implications in the management of risk in the supply process which requires a special procurement organization and program commitment to be successful. The Coming system of managing critical materials and factors in development of alternate new suppliers and products is discussed.

Jan 1, 1989