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By Selby DW, Hamill J, Cauley ID, Thomas I, Thornton AJ

The main objective of sulphide flotation in a cassiterite concentrator is to remove sulphide minerals (pyrite, pyrrhotite and sometimes chalcopyrite) from the ore prior to gravity concentration. Tin losses in the sulphide flotation stage account for a significant proportion of the total tin loss. separate studies of the sulphide flotation circuits of Renison Ltd and Cleveland Tin Ltd were conducted to investigate reasons for the tin losses. Sampling surveys were conducted in the rougher-scavenger and also the regrind-cleaner sections of both plants. In both plants, the rougher circuits recover excessive quantities of liberated cassiterite, while recovery of the desired composite cassiterite-sulphide fraction is low. The regrind mills are successful in liberating the composite cassiterite in the rougher concentrate, but at the expense of increasing the proportion of very fine tin mineral. The cleaner circuits recover between 40 and 60% of the cassiterite received, and this is all lost.

Jan 1, 1978

By OÆBrien D. R

Up until June 1988, Mount Thorley Coal Handling and Preparation Plant disposed of tailings by two methods. Approximately half of the plant tailings was mechanically dewatered by solid bowl centrifuges mixed with plant reject and was subsequently disposed in mine overburden spoils; the remainder was pumped to tailings ponds. Both future mine planning and environmental constraints could not allow for the long term construction of more tailings ponds so, following evaluation of available dewatering technology, belt press filters were selected for the treatment of tailings in excess of the capacity of the existing solid bowl centrifuges. Commission of the four 2.5 metre wide belt press filters soon showed that marked differences in performance were experienced when treating different coal seams. Further analysis showed that the coal tailings from different seams were quite different in terms of clay mineralogy, and these differences could be correlated with varying degrees of filter performance. Poor filter performance was experienced with coal tailings rich in sodium montmorillinite clays. A number of variables were investigated including in-line mechanical mixing of flocculant and feed slurry, cation exchange reagents such as gypsum, and upstream addition of cationic flocculant. In order to achieve satisfactory performance on the worst tailings, a combination of all of the above was required. In this paper, the reasons for selection of belt press filters and the program of investigations and testwork required to arrive at satisfactory belt press filter performance for the treatment of troublesome bentonitic rich tailings are discussed.

Jan 1, 1989

In most mining operations the ore undergoes several processes such as drilling, blasting, loading, hauling, crushing, grinding and liberation to become the final salable product. Drilling and blasting is an important step in this process chain and itÆs results such as fragmentation, muckpile shape and looseness, dilution, damage and rock softening effect the efficiency of downstream processes. The value created per ton of broken ore is the difference between the price it commands when sold as the final product and the cost to produce it. Traditionally, the total process in the mining industry is classified into two groups as mining and milling. These are managed as separate cost centres inspite of the interdependency. Each process has a budget and production target and emphasis is usually on maximising production (tons) and minimising cost rather than the overall profitability of the whole business unit. The efficiency of each process is considered to be satisfactory as long as they are within budget and meet the production targets. The mine and mill managers usually try to optimise each process independently rather than the entire process. This paper discusses the potential pitfalls of decreasing the drilling and blasting cost per ton of broken rock without considering its impact on downstream processes. It introduces a holistic approach to blast optimisation by identifying and measuring the leverage that blast results have on different downstream processes and then optimising the blast design to achieve the results that maximise the overall profitability rather than just minimising the drilling and blasting costs. This paper demonstrates the benefits of such a holistic approach to blasting based on computer model simulations and field studies from metal and open cut coal mining.

Jan 1, 2001

The O.K. deposit occurs within a belt of cherts and spilitised basic volcanics near the western margin of the Hodgkinson Province. The tabular to lenticular shape and gross conformability of the ore bodies; the common occurrence of colloform, framboidal and banded textures in the ores; the lack of significant alteration adjacent to the massive ore horizons and the apparent restriction of stockwork mineralization to the foot-wall side of the massive ore zone at the O.K. mine, all favour a syngenetic origin for the massive sulfide bodies. Furthermore, the micro- structural evidence suggests that the ores have undergone the same deformational history as the country rocks. The invariable association of the ores with spilites; the S isotope values and Co-Ni contents of the pyrites, together with the primitive metal assemblage (Fe, Cu, minor Zn) strongly favour a basic magmatic source for the sulfides. It is suggested-that the sulfides were probably precipitated sub aqueous- ly during a hiatus in volcanic activity. The O.K. deposit is of the cupreous pyrite variety, but unlike other well known occurrences of this type, it does not con- stitute part of an ophiolite complex. While the host volcanics exhibit strong ocean floor tholeiitic affinities, no associated ultra

Jan 1, 1978

By G W. Scott, H M. Lukey

The Lake Superior Region has been a producer of iron ore for over 150 years. Early mining operations concentrated on direct shipping ores, which are the result of post-depositional upgrading principally by deep weathering. As direct shipping ore reserves became depleted, the focus changed to the production of iron ore pellets from taconite. The post-depositional processes responsible for upgrading taconite are regional metamorphism, contact metamorphism and hydrothermal processes (Clout and Simonson, 2005). While these processes are important in iron ore genesis they can also contribute to liberation problems and in some instances reduced pellet quality (Han, 2004). Low-grade metamorphic mineral assemblages can negatively impact liberation and pellet quality. Low-grade iron formation may contain a suite of carbonate minerals including ankerite, dolomite, kutnohorite, siderite and magnesiosiderite. Variation in the distribution and composition of siderite and magnesiosiderite makes controlling the MgO content of pellets difficult. Carbonate minerals also require calcination in the pellet induration process, which requires additional heat to be added to the system, slowing down the induration process and reducing throughput. Prediction of carbonate mineralogy and carbonate mineral chemistry is an important goal of ore characterisation for pelletising properties. Contact metamorphism causes changes in mineralogy and grain size (Klein, 1973; Gunderson and Schwartz, 1962). Increasing the grain size of magnetite should improve its liberation characteristics. However, plant grinding targets may not allow the coarse-grained, more easily liberating magnetite ores to increase throughput and can actually result in decreased throughput due to recirculation. While magnetite and martite ores are well understood (Lukey, Johnson and Scott, 2007) late open-space filling microplaty haematite ores are not. These ores, while composed of similar minerals, have a unique genesis that results in fine grain size and complex textures that present liberation challenges and often make interpreting laboratory metallurgical test results more difficult.

Jan 1, 2007

By C Parihar, R Garg, A Bhandari, S Bhandari

Blasting can impact the efficiency of entire downstream mining operation. Individual technology solutions for blasting have been available in the industry for many years but all of them only cater for certain aspects of blasting. Many of them are based on individual research and/or experiences. Some of the available software solutions are not suitable to be used in the field as that they need advanced skills or tools. Also, most do not take technology advancements like mobility, advanced data analytics, web solutions and integration into consideration. Hence, no technology platform is currently present in the industry that addresses all potential needs a blaster may need in an integrated manner.This paper presents an integrated solution that takes care of all aspects of blasting – design blasts according to mine plan; collect data after drilling has been carried out (as there is often difference in designed and actual drilled hole locations in the field); predict blast results in terms of fragmentation, flyrock, ground and air vibrations, wave front reinforcement and flyrock distance; and after assessment, allows changes in charging, delay timing and sequence. The technology solution is a secure, cloud-hosted, web-based software-as-a-service solution that can be accessed from anywhere. Also it has a mobile app, which is available for both Android and iPhone/iPad. The mobile app is also integrated with the web-based solution using application programming interface calls to the central data repository.Case studies for two limestone mines are presented where this solution is being used in its initial format. This software platform enabled analysis of the outcome from a previous blast pattern and then subsequently allowed optimisation of blasting operations based on historical data. Uses of this platform have resulted in improved key performance indicators in these two limestone mines. The mobile app as part of this platform enables extensive field blast data capture and analysis and also various predictions before a blast. Data collected include blast parameters, individual hole charging, initiation pattern, videos, photographs and vibration records for analysis/reporting. The key features of the solution are a blast designer, a detailed blast data collection/analysis and a series of environmental predictors. These predictors give blast results in terms of fragmentation, flyrock, ground and air vibrations and wave front reinforcement and take remedial steps before blasting to optimise and control adverse environmental impact. Many features, such as fragmentation predictor and mobility solution, are completely unique features that are not available elsewhere in such a field personnel-friendly manner.CITATION:Bhandari, S, Parihar, C, Garg, R and Bhandari, A, 2015. An integrated technology solution for optimised and environmentally-controlled blasts, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The objective in design of an excavation in a jointed rock mass is to achieve a prescribed degree of control of rock mass displacement around the excavation. Any excavation in jointed rock usually involves slip and separation along discontinuities as well as translation and ro- tation of constituent rock blocks. Thus, any acceptable model of behavior around an excava- tion must be capable of simulating the force displacement paths followed by the constituent elements, including rigid body translation and rotation. The distinct element method models such behavior by simulating the rock mass as an assemblage of rock blocks which interact through corner and edge contacts. Discontinuities are regarded as boundary interactions between blocks with joint behavior prescribed for these inter- actions. Introduction of structural element logic allows a variety of installed support sys- tems to be modeled. The response of the support to axial, transverse, and flexural loads is based on explicit algorithms similar to those used in the distinct element formulation. This allows large displacements and rotations and general non-linear constitutive behavior for both the support elements and the interface with the rock. This paper describes both the distinct element and structural element formulations and demonstrates several applications involving sup- port interaction with jointed rock.

Jan 1, 1987

By D J. Bradshaw, E M. Wightman, B Newcombe

Flash flotation plays an integral role in many of the gold and sulfide mineral concentrators around the world, and yet despite this widespread use, very little information on this unit process is available in the published literature. For operations to maximise the performance of their flash flotation circuits, understanding how these cells operate, the nature of the particles they target and how to predict whether a flash flotation cell should be used on a specific ore type is of vital importance. This paper provides a summary of the key findings of a large flash flotation research project based in the operating environment of a refractory gold concentrator. The influence of key flotation performance criteria including gas dispersion, residence time and particle segregation within the cell will be discussed and recommendations for process improvements will be made throughout. The nature of the particles within the flash cell will be examined, as will the impact on the type of particles that are passed to downstream processes when the flash flotation cell is taken off-line. The development of a laboratory method to determine whether an ore is suitable to undergo the flash flotation process is also presented for its potential to aid in flow sheet development and optimisation for new ores.CITATION:Newcombe, B, Bradshaw, D J and Wightman, E M, 2012. Into the belly of the flash à Insights into the mechanisms at work within a flash flotation cell, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 163-170 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By D P. Blair

The theme of this conference is blasting productivity. This article only considers the technology aspect of this theme, and in particular, the collection and analysis of experimental data. In many cases, field trials are set up to collect data on variables such as fragmentation and vibration with the aim of comparing different explosive products and/or blast designs. An important aspect of such trials is the collection of sufficient data to draw sound conclusions. In this regard, there is no doubt that the scatter in real data is the root cause of all problems of obtaining misleading results due to an insufficient number of trials. This article shows that the typical one-off trial has a high probability of producing misleading information, which could be considered to be worse than having no information at all. Assuming that sufficient data has been collected, this article also highlights the methods that can be used to make the most of that data. These methods include the application of appropriate statistics that are dependent on the nature of the scatter in the data, and the use of some of the more recent filtering and spectral approaches that can be used to reduce the noise in measured blast signals and increase the resolution of their spectral characteristics.

Nov 8, 2011

A system for rapid on-line determination of weight percentage coal in slurry and weight percentage ash in coal has been developed at the Julius Kruttschnitt Mineral Research Centre, University of Queensland. The gauging system is suitable for use with coal flotation slurries or slurries having a maximum particle size of about 1 millimeter. The system is based upon measurement of gamma ray transmission; radioisotope sources emitting photons of two widely different energies are employed. The inaccuracies of measurement that would normally result from variable amounts of air entrained in the slurry are substantially reduced by pressurising the slurry to approximately 2MPa (300 psi) using a Mono pump. The equipment can be used to make measurements on more than one slurry stream by pumping streams sequent- ially. The system is being tested at the Peak Downs Mine of the Utah Development Company in Central Queensland. This paper describes the theoretical principles of the gauge design, the experience gained to date in the commissioning of the equipment, including the installation of a PDP 11/03 computer, and the progress made in developing satisfactory interpretations of the gauge count-rate output.

Jan 1, 1978

By N K. DavT, A Coggan

The performance of in situ, shallow water covers in controlling acid generation was evaluated at four recently decommissioned pyritic uranium tailings sites at Elliot Lake, Ontario, Canada. The tailings are acid generating, having a pyrite content of approximately five to ten per cent and a very low to non-existent alkaline buffering capacity. Adverse market conditions led to the closure of all operating uranium mines in the early- to mid-1990s, followed by rehabilitation and decommissioning of mine and waste management facilities. In order to control acidic drainage, all new and active tailings areas at Denison, Quirke, Panel, Spanish-American and Stanleigh mine sites were re-engineered to provide in situ submersion of these tailings under shallow water covers. The tailings impoundment dams were upgraded and reinforced or in some cases reconstructed, to minimise seepages and provide a minimum 1 m depth of water cover. With the exception of Stanleigh mine, which was closed in 1996 and rehabilitated during the late-1990s, the water covered Tailings Management Areas (TMAs) at other sites have been in operation for a period of six to nine years. The surface water quality at these sites is maintained at near neutral pH conditions by periodic addition of lime slurry to the established water covers. Additional treatment of effluent is provided as required to meet the discharge water quality standards. The performance of the established water covers at the sites was evaluated by analysing the annual equivalent limestone consumption data. The results were compared with the performance of an older, decommissioned Nordic TMA, which was rehabilitated using revegetation techniques. The water covers at these sites are performing as designed and acid generation has been reduced to low levels. Based on the total amount of yearly equivalent limestone required to maintain water quality in the water cover and at the effluent treatment plant, it is concluded that acid generation rate at the Denison TMA has reduced to less than 0.15 per cent of its pre-water cover conditions during normal operation and rehabilitation periods. In comparison to the revegetated Nordic TMA, the acid generation rates at Denison and Panel TMAs have decreased to less than 1.6 per cent of that at the Nordic TMA. The acid generation rate at the Quirke TMA was comparable or only slightly lower than that at the Nordic TMA because of its unique terraced cell configuration, having tailings in five hydraulically interconnected cells at different elevations. Historic acidity and oxidation reaction products, accumulated during normal operating and pre-water cover periods, are flushing from upstream locations to downstream cells, thus requiring much higher equivalent limestone additions for acid neutralisation and effluent treatment.

Jan 1, 2003

In 1997, the Australian coal industry through Standards Australia committee MN-001 Coal and Coke recognised the need to produce a Standard giving some instruction on how to inspect and audit mechanical sampling systems. A Guide was developed by sampling subcommittee MN-001-04 and in 1999 the Standard was released as AS4264.5 æGuide to the Inspection of mechanical sampling systemsÆ Coal and Coke. Since that time the author has assisted with other committees in developing the Guide for other commodities such as concentrates and a generic standard for particulate materials. (AS4433.6 released 2000). The Coal and Coke guide is also currently a work item for ISO Standards. This paper is focused primarily on auditing and inspection procedures for coal mechanical sampling systems. It highlights the need for at least a three level inspection protocol where the operators manning the system maintain operational checks, the operators are regularly supervised by the company managing the system and once per year an independent auditor inspects the whole system to ensure compliance with design and standards. It does not cover short- and long-term maintenance of individual systems. With companies already certified to the ISO9000 series, this guide forms the framework to bring the operation and inspection of their mechanical sampling systems into line with these principles.

Jan 1, 2005

Both as an energy source and as a raw material, natural gas is playing an increasingly important role as a catalyst for the development, continuation and rebirth of mining projects in Australia. Pipelines are the vital link in making natural gas available to a region and to individual mines. This paper will cover the role of pipelines in supplying mining projects in Australia, the development and status of the Ballera to Mount Isa gas pipeline and the future prospects for gas pipelines in the Carpentaria Mineral Province.

Jan 1, 1998

By Aziz NI, Guo H

Most of the existing models of the mechanisms of drilling and cutting processes are oversimplified in both stress state and failure criterion. On the other hand numerical modelling techniques are a more versatile method with great potential for development. In reviewing drillability and predicting performance of excavation machines the empirical tests, which simulate the physical breakage action in excavating processes are seen to be the best in terms of penetration rate predictability. Future methods of determination of drillability should concern the breakage characteristics and rock abrasivity involved in the two basic types of attack, i.e., percussive and rotary drilling.

Jan 1, 1988

By Singh RN

Monolithic packing systems have gained in popularity as a gate side packing method. However, there has been no detailed investigation to assess their underground strength behaviour. This work includes the laboratory and in situ investigation for strength behaviour determined on various monolithic packing materials namely Tekpak-XX, Hydropak-20, Hydropak-30, Astrapak-3R, Flashpak, Thyssen pack and Aquablends. A simple technique for assessing the pack strength was developed at the laboratory by using a penetrometer, of which penetration resistance can be directly correlated with the uniaxial strength of the pack. The in situ strength investigations were made on core samples obtained from three pipes inserted inside the pack, while the penetration test were made on the pack surface. The in situ results indicated that the packing material develops an inconsistent strength on various part of the pack which was mainly related to an inadequate mixing of grouts inside the pack.

Jan 1, 1992

The paper continues an account, begun in a previous paper, of experimental work carried out by the author whilst a member of the metallurgical staff at the Cockle Creek Works. The general method of the description of the plant and works practice adopted previously has been followed.The paper is a short account of the methods used in and the results of an investigation of the fume losses from the various parts of the plant.MEASUREMENT OF VOLUMETwo independent methods were used. The first depended on a number of pitot-tube measurements of velocity. These readings were taken in the stacks leading from the various furnaces at a considerable height above the ground so as to obtain as regular conditions as possible at the points where the readings were taken.Three openings were made in each stack and the pitot tube inserted into each opening in turn and readings taken at the centres of imaginary areas of equal size. The average velocity in the stack was thus obtained.After four tests had been made at the smelter stack, which removed the gases from all blast furnaces in use, the centre of velocity of the gases for each test was calculated and was found to be practically constant in position. The previous procedure was varied in subsequent tests on this stack by taking a succession of readings at the centre of velocity instead of at various points...

Jan 1, 1925

By J E. Powalisz

"The application of automated sampling techniques can help to provide a representative sample of process fluids and slurries that provide data for controlling process, custody transfer and quality assurance and quality control purposes.The automation of sampling provides a more consistent and reliable sampling process and eliminates many of the human-induced errors. Automated sampling can also provide a higher degree of safety in the plant/processing environment as well as better bottom-line results.Automated, fixed volume samplers can provide a very representative sample by integrating many small ‘grabs’ of sample from a process. Automated samplers can be controlled in a variety of ways to optimise the sampling process, including:cycle ratedwell timetotal volume.Properly selected and applied, an automated sampler can effectively isolate the operator from the process fluid during sampling and, to a great degree, during sample container collection.A variety of materials of construction, including seals, are available to handle demanding mining applications. Alloy 625, alloy 2205, AL6XN® and even certain plastics are used successfully in mining slurry applications.This paper explores the application of automated, fixed volume, batch style samplers in copper/nickel and gold processing, specifically pregnant leach solution and extraction fluids.Several specific field applications are discussed, including process installation details, hardware and operation.CITATION:Powalisz, J E, 2014. The application of automated samplers in copper/nickel processing, in Proceedings Sampling 2014, pp 35–42 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 29, 2014

By Osborn G

The bulk flotation behaviour of an industrial rougher bank has been determined with a view to characterising the size iepend ent behaviour of the identifiable nineral groups present. A relatively simple flotation model, based on first order kinetics and the assumption of perfect mixers in series ias been used to provide a fit to the operation of the cells. The adequacy of the model is discussed in relation to the characteristics of the ore and the size iependancy of the parameters. It is shown that improved fits are possible if the model accounts explicitly for this size dependancy and demonstrated how the model may be of use in prediction of the grade recovery relationships for different operating conditions as an aid to plant optimisation.

Jan 1, 1986

The winning and upgrading of mineral raw materials necessarily includes size reduction, which serves the liberation and production of marketable products from highly valuable and bulk materials. For crushing, the following factors can be duly accounted for depending on material type and the selection of the suitable machine: ò producing a particular size distribution, ò producing a particular grain shape, ò selective comminution, ò gentle comminution, and ò producing a size range required by a specific process and/or for a specific product.

Jan 1, 1993

By Martin C. H, Met B

INDEX OF CONTENTS:1. Introduction, Explanatory; and Reasons for Coal Cleaning.2. Principles on which Coal Cleaning is based.3. Location of Broken Hill Proprietary Co. Ltd. Plant.4. Description of Processes Selected Barvoys Bath Process; Barvoys Medium Preparation and Treatment; Static Dry Cleaning Plant.5. Detailed Description of Plant.6. Typical Results of Cleaning Operations.INTRODUCTION, EXPLANATORY, AND REASONS FOR COALCLEANING:The Institute proceedings have not previously published any matter on coal cleaning and the reasons thereof; in consequence it has been deemed advisable to allot a part of this paper to explanatory matter, prior to entering into a detailed explanation and description of the Newcastle plant.At the outset it would be as well to consider briefly the kinds of materials from which coal has originated. All coals represent some stage in the decomposition and transformation of vegetable matter laid down in prehistoric times, the vegetable matter undergoing numerous geological changes, such as submergence, overlaying by sediment, with subsequent pressure and re-elevation; these processes may...

Jan 1, 1946