Search Documents

After the minim operation, most raw materials that occur in the earth's crust require some form of processing or refining before they can be converted into a final end product. In the mineral industry these remarks apply to materials such as iron ore, bauxite, limestone, copper ore and many others that are found in Australia in large quantities. Processing plants for these raw materials operate more efficiently, however, if the feed to them is consistent in both physical and chemical characteristics. Such uniformity rarely occurs in nature so that some form of homogenisation, or blending, is required ahead of the processing plant. Bending also assists the mining operation itself by reducing; the need for selective mining and, by combining high and low grade materials, a more uniformly graded, commercially acceptable product can be obtained, thereby increasing the commercial life of a mine or quarry. Bed blending is the most efficient of the processes available, and following its development in the United States in 1905, over 100 plants have been installed, or are under construction, all over the world. The original process, the Robins--Nessiter system, has been the subject of continued improvements and refinements, so that economical capacities are possible from less than 100 l.t.p.h. up to 10,000 l.t.p,h. and beyond.

Jan 1, 1969

By S Wilkinson, S Black, L van den Berg

"The mine ventilation system plays an important role in mitigating human exposure to diesel particulate emissions (DPM), exhaust gases and heat in underground mines. The mine’s secondary ventilation systems are critical for diluting contaminants when working at the face of a heading. To improve these systems it is important to understand and visualise the localised air flow profiles. We have considered an approach that includes both tracer gas measurement–modelling to analyse this complex flow behaviour in a heading. The use of tracer gas enables reliable measurements of flow behaviour and differentiation between the contributions of various contaminant sources including DPM. A pilot study was conducted to demonstrate how tracer gas can be used to directly measure the effectiveness of ventilation dilution in a heading during shotcrete activity. This activity is considered to be one of the more challenging areas for diesel exhaust exposure management. Exposure sources include the diesel engine of the spraying equipment (Spraymech) and concrete agitator truck (Agi) that supplies the shotcrete. During operation both the Spraymech and Agi operators are located outside the equipment’s air-conditioned cabins and both are exposed to diesel exhaust. In the pilot study tracer gas was injected directly into the Spraymech exhaust stream. This allowed thorough mixing, ensuring the tracer gas was able to track exhaust gases and particulates released to the heading. The release was repeated at three different headings with varying degrees of secondary ventilation controls. The study showed that small changes to the secondary ventilation system can significantly impact the contaminant concentration. It also demonstrated that tracer gas can be used to isolate different contaminant sources. The intent is to use this technique in a more comprehensive study to develop best practice guidelines for secondary ventilation installations. This paper presents the technique used and the preliminary results from the pilot study. CITATION: Wilkinson, S, van den Berg, L and Black, S, 2015. Application of tracer gas flow profiling to improve secondary ventilation practice – a pilot study, in Proceedings The Australian Mine Ventilation Conference, pp 345–352 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 31, 2015

By J J. Cilliers, K Hadler, A W. Stra

This paper examines the use of the FrothSim flotation simulator to improve the performance of an industrial column flotation cell. The performance of an industrial retreat column cell is simulated, and, from the discrepancies between the simulated and experimental results, a problem with the wash water distribution is postulated. The scientific reason for the reduced performance with uneven wash water addition is described in detail. Further simulations indicated the potential for improvement with an even wash water distribution, resulting in both improved performance and reduced wash water usage. The simulated uneven wash water distribution was confirmed industrially, and the headers were redesigned and installed. A sampling campaign to compare the performance before and after the modifications showed that the flotation performance was improved dramatically, with a statistically significant decrease in gangue recovery, without a commensurate reduction in valuable mineral recovery.

Jan 1, 2005

The introduction ofa submerged entry tundish nozzle incorporating a cylindrical internal space for argon distribution to its inner bore slab is described. In co-operation with the refractory supplier, four major phases of nozzle development have been undertaken. Problems as well as successes are outlined.Significant reduction in alumina clogging ofnozzles has been achieved along with a decrease in nozzle consumption, using resin bonded alumina graphite with up to 4 different materials "zoned" to give resistance to thermal shock, gas leakage, and erosion.

Jan 1, 1985

By R Higashi, D Maruoka, T Murakami, Y Iwami

The ironmaking industry consumes a large amount of fossil fuel derived carbon as heat source, reducing agent of iron ores and carburising agent of reduced iron. Although the demand for drastic decrease of carbon dioxide emission, carbon is an essential element for smelting process of molten iron. The carbon recycling ironmaking process by circulating CO has been already proposed to achieve carbon neutrality. However, the production of molten hot metal is not considered in this process because sufficient amount of carbon does not dissolve in reduced iron by CO. Therefore, our group has suggested a new carbon recycling ironmaking process which can produce hot metal. In this process, free carbon and iron carbides produced by carbon deposition reaction using metallic iron as a catalyst are used. It is known that only Fe3C is obtained as iron carbide by using CO gas, however, Fe5C2 is also produced by adding H2 gas. The composite agglomerated with these carbonaceous materials and fine iron ore (Deposited Carbon-Iron oxide Composite: DCIC) is reduced and melted in a furnace. It is reported that Fe3C in DCIC accelerates the reduction reaction and melting of the composite. In this study, the effects of iron carbides and free carbon on the melting behaviour of DCIC are investigated. Fe3C, Fe5C2 and free carbon were produced by vapour deposition using porous iron whiskers and CO-CO2-H2 gas. These were agglomerated with hematite reagent at a certain ratio to prepare DCIC samples with and without Fe5C2. The samples were heated up to 1300°C in inert atmosphere. The DCIC containing Fe5C2 completely melted and iron nuggets were obtained after the experiment. This behaviour was not observed in the composite without Fe5C2. This indicates that using Fe5C2 is more preferable than Fe3C for molten iron production using DCIC.

Jun 19, 2024

By Clifford C. E

1 eat my peas with honey I've done it all my lifeIt makes them taste rather funny But it keeps them on the knife.Innovation is that elusive characteristic which involves the determination of multiple and unique response to a problem, and then commitment to and action from the best of the alternatives.

Jan 1, 1993

By T R. Gibbons, I Grayand

Geotechnically massive strata may lead to a host of problems during longwall mining. These include windblast on initial goaf fall, sudden loadings on powered supports, periodic weightings, fractures that may propagate to surface, and extreme subsidence problems. It is essential to identify these problems prior to mining and to appropriately deal with them. The problem is essentially that the rock mass does not breakup evenly and when it does so it tends to produce large blocks which may suddenly move. The rock types that produce these problems tend to be massive sandstones, massive siltstones and sometimes igneous sills. The fundamental problem with these is that they do not breakup readily. This is because the ratio of stress they are subject to compared to their strength is low. Thus, the shallower mines with lower stresses are more subject to this problem than deep highly stressed ones with similar strength rock.

Nov 29, 2022

By M Malec, J Szczerbinski

Hazards in underground mines are concomitant with the mining of mineral deposits and have their source in a minerÆs work environment. The authors of the paper have undertaken a trial classification of these hazards into three groups, depending on the sphere of their occurrence:lithosphere, ie rock mass, atmosphere, ie air in mine workings, and technosphere, ie machines, equipment and facilities in mine workings. The lithosphere creates such hazards as bumps, rock outbursts, the atmosphere is a factor causing fires, methane explosions and climatic hazards, whereas accidents concomitant with an operation of machines and equipment occur in the technosphere. Assuming that the number of accidents in the mining industry, concomitant with hazards, reflects the degree of safety, it has been shown, that in Poland they are under control to a large extent.

Jan 1, 1999

By A C. Robertson

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authorsÆ personal observations and experience.

Jan 1, 1998

By S J. Tear, L D. Queen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Frieda River Project is located in the north-west of Papua New Guinea. The target commodities for a bulk mining operation are copper and gold associated with a large felsic porphyry system. The project comprises a series of deposits, with the Horse-Ivaal-Trukai (HIT) being the largest. It also includes the adjacent smaller Koki and Ekwai deposits.Previous resource estimates for the HIT were made using 14 separate mineralised domains based on structure, copper grades, lithology and alteration. H&S Consultants (H&SC) has revisited the deposit and concluded that a simpler methodology could be used for resource estimation without using wireframes as hard domain boundaries. This conclusion is based on reviewing all the available geological data combined with geological and resource experience of porphyry deposits.It is generally acknowledged that porphyry deposits form by diffusion of mineralising fluids through the host lithologies, meaning that sharp boundaries are unlikely unless these fluids encounter specific physical or chemical boundaries. It is important to prepare a comprehensive geological model prior to attempting resource estimation as it forms the framework for the estimates; however, not all geological features may be relevant to the distribution of mineralisation and there can be a tendency to overcomplicate the estimation process by using too many domains. Unless a hard boundary can be identified consistently and unequivocally, it is generally better not to use a boundary in that location.H&SC completed unconstrained models with no top-cutting using both a simple flat search ellipse and a steep search ellipse to generate global resource estimates reported within a predetermined pit shell at a 0.2 per cent copper cut-off. Both outcomes are within 10 per cent for the tonnes, contained copper tonnes and gold ounces compared to the constrained resource estimate. The slight differences are most likely due to the different search strategies, but also indicate the robustness of the unconstrained modelling approach.CITATION:Queen, L D and Tear, S J, 2015. The Frieda kiss – keeping it simple , in Proceedings PACRIM 2015 Congress, pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Zani J. A, Jackson W. D

Bauxite was discovered in the Kimberley in 1965 by an Amax field crew. Reserves of 230 million tons, of bauxite. averaging 47% total alumina on Mitchell Plateau and 980 million tons averaging 36% total alumina on Cape Bougainville have been indicated by the results of drilling and bulk sampling. Laterite which contains the bauxite deposits caps basalt and interbedded sandstone and siltstone of the Carson Volcanics formation. Bauxite on Mitchell Plateau is 3.2 metres thick on average and is underlain successively by nodular ironstone, clay and basalt. The major components of the bauxite are gibbsite,boehmite, hematite and goethite containing some alumina, anatase and clay minerals. Quartz and vanadium oxide are minor constituents. Boehmite and hematite are concentrated near the surface, whereas gibbsite and goethite predominate at depth. The bauxite profile consists of ferru- ginous, pisolitic and gibbsitic zones with increasing depth. Cape Bougainville bauxite is 8.6 metres thick on average and of tubular structure; its mineralogy is relatively uniform..

Jan 1, 1973

The theme of my address to your Institute, indeed its name, is "The Mineral Industry - What Next?" Knowing that I was required to make four appearances, and not wanting to be too repetitious, I wrote a rather long speech of which I will deliver various sections at different places, with a common introduction. Specific areas I have addressed are "Exploration", "New sources of minerals and energy", and "Mining and metallurgy of the future".

Jan 1, 1984

By D J. Bradshaw, E M. Wightman, C L. Evans, B Triffett

During the commissioning phase of Prominent Hill, periods of reduced recovery were experienced with higher-grade ore blends. This was unexpected and as part of the process to identify the cause, surveys were conducted in May 2009, with two different ore blends (copper grades: 1.94 per cent Cu (blend 1) and 2.49 per cent Cu (blend 2)). Metallurgical performance was assessed in terms of rougher recovery and grade with consideration of both pulp and froth effects. In addition, hydrodynamic measurements (gas hold up, bubble size, superficial gas velocity) as well as measurements of bubble load and top-of-froth grade were taken during the surveys and full mineralogical assessment of selected streams completed to characterise the nature of the differences. The metallurgical results showed that the lower performance was obtained with blend 2 which contained the higher amount of chalcocite and was higher-grade. Analysis of the survey data showed that for both ore blends more than half of the copper loss occurred in the +38 ¦m size fractions. Almost 30 per cent of the copper in the +38 ¦m fractions that reported to the rougher tails during processing of blend 2 was liberated compared to less than five per cent for blend 1. Additionally almost 60 per cent of the copper in the +38 ¦m fraction of blend 2 was chalcocite compared with approximately 20 per cent in blend 1. This paper discusses the sensitivity of the chalcocite-to-surface chemistry effects causing marked reductions in recovery either through reduced pulp recovery or froth phase (detachment) effects. The reagent suite and operating conditions were subsequently changed and the recoveries increased substantially and the sensitivity to ore changes eliminated. It should be noted that subsequent optimisation work, which focused on recovery improvement, has led to copper recoveries of over 90 per cent being achieved.CITATION:Bradshaw, D J, Wightman, E M, Evans, C L and Triffett, B, 2012. Characterising the reasons for the difference in performance of two ore blends in early processing at OZ Minerals Prominent Hill Operation, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 273-278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Riley S. J

The basic aim of mine planning is to design mine layouts and schedules that achieve optimisation of operations, minimum cost and maximum resource recovery. Successful accomplishment of this aim is facilitated by timely and comprehensive rehabilitation planning commencing at the pre-feasibility stage and continuing until the end of mining. Incorporation of a final landfomt design for waste rock dumps in a mine plan requires a prediction of surface stability, which may be achieved through erosion modelling. Erosion prediction models can be placed in two broad categories: soil loss prediction models eg USLE and CREAMS, and geomorphic models such as SIBERIA. A waste rock dump landform design based on selected slope form and grade and drainage systems should be developed as part of planning. A digital terrain model (DTM) of the landfonn should then be produced which can be modelled for long-term erosional stability using pre-determined parameter values. If acceptable standards of stability are not achieved, the landform should be redesigned and remodelled until the desired result is obtained. The planning process incorporating models requires knowledge of spoil or waste rock properties and model parameter values. This information is site specific and can be obtained from drill cores or costeans at the pre-mining stage and from spoil or waste rock during the mining stage. Realistic model parameter values are critical in post-mining landfonn design and can be obtained by several methods, including rainfall simulation, monitoring, geochemical analyses and grain size analysis.

Jan 1, 1994

By BTrubT M

In the roast-leach-electrolysis process for the production of zinc, iron contained in zinc concentrates is converted to zinc ferrite during roasting. At Canadian Electrolytic Zinc (CEZinc), the Outokumpu Conversion process is used to simultaneously leach zinc ferrite and precipitate the iron as jarosite. These simultaneous reactions, while providing good process stability, require a compromise between optimum conditions for maximum zinc extraction and efficient iron precipitation. An improved conversion process has been identified which can achieve >99 per cent zinc extraction and more efficient jarosite precipitation to residual iron concentrations of

Jan 1, 1993

Slide presentation at conference

Jan 1, 1996

The purpose of this work is to determine the equilibrium-state of the aqueous-solution which is produced by the leaching processes, including natural weathering of pyrite minerals. The latter can lead to acid-mine-drainage (AMD). The ferric iron species (Fe3+) resulting from bacteria-catalysed oxidation of ferrous iron (Fe2+), in the presence of water and air, is known to bring about steady-dissolution of minerals chalcopyrite (CuFeS2), sphalerite (ZnS), pyrite (FeS2), and so forth. Good-aeration, relatively high-porosity and sufficient bacterial activity tend to promote leaching in waste-rock-dumps. The composition of the aqueous-phase that accumulates in the pore-space (or in open-pits) is of practical interest as it would strongly influence the leaching of both sulfide and non-sulfide minerals. Since the reactions among the various ionic species occur relatively fast, the solution-phase may be regarded as approaching a state of virtual-equilibrium and it is possible to determine by computation the respective concentrations of the many dissolved species. For the Cu-Fe-H-O-S system, these species may include: H+, Fe2+, Fe3+, Cu2+, HSO4-, SO42-, OH-, CuSO4o, H2O, Fe(OH)+, Fe(OH)2+, Fe(OH)2+, Fe2(OH)24+, Fe(SO4)+, Fe(HSO4)+, Fe(HSO4)2+, and Fe(SO4)2-. The aqueous-system which may be constituted from appropriate mole-quantities of H2SO4, FeSO4, Fe2(SO4)3, and CuSO4 is in fact the result of various natural processes (reactions) and due respect must be accorded to the extents of these reactions. The present model computes the equilibrium molalities of the foregoing ionic and neutral aqueous species, using the iterative equilibrium constant method that ensures strict-adherence to charge-balance and elemental molar-balance constraints. The dissolving sulfide-minerals (FeS2, CuFeS2) consume Fe2(SO4)3, H2O, and O2 and yield FeSO4, H2SO4, and CuSO4 while the aqueous-phase tends to become progressively acidic (declining pH) reflecting the gradual increase in the extents of sulfide-dissolution reactions. The equilibrium-state of the solution-phase is computed for specific set of values for the extents of respective reactions. The temperature and pressure of the system are 25¦ C (298.15 K) and 101.325 kPa (1.0 atm), respectively. The mica-like minerals such as the biotite [H2K(Mg,Fe)3Al(SiO4)3] tend to consume much of the H2SO4(aq), with the extracted K+, Mg2+, Fe2+ and Al3+ ionic species accumulating in the solution. The precipitation of the jarosites (potassium, hydronium, or ammonium) contributes to the removal of ferric and ferrous species from the solution-phase. In the present work, the emphasis is on predicting the compositions of the aqueous- and condensed-phases with advancing time or increasing æextent of reactionÆ. The results of such calculations are compared to published data on raw AMD (acid-mine-drainage).

Jan 1, 2008

By D Kepert, C Simpson, D Edwards

Channel iron deposits (CID) currently supply over 40 per cent of the seaborne iron ore trade out of the Hamersley Province. The two well documented producing systems (Robe and Marillana palaeochannels) were both discovered during early reconnaissance mapping principally by BHP Billiton (BHPB) and Geological Survey of Western Australia (GSWA) during the mid 1950s to early 1960s. Both crop out extensively over the majority of their length. Hot on the heels of Fortescue Metals Group 2004 - 2005 discovery of approximately 2.6 billion tonnes (Bt) of undercover iron ore mineralisation in the Chichester Range, the Fortescue Exploration Department turned its attention elsewhere throughout the Hamersley Province. Reappraisal and analysis of publicly available data and ground truthing of developing models led to the recognition of the Solomon palaeochannel system. Subsequent exploration defined a world-class Resource of some 1.9 Bt of iron ore mineralisation of which the great majority is buried CID. Apart from the Marillana CID system, the Solomon region is the only major CID with significant tonnes of sub two per cent alumina CID with over 500 Mt delineated to date. Exploration has also outlined significant supergene bedded and detrital iron ore mineralisation. Ongoing drilling is expected to increase the resource base both in terms of tonnes and confidence. This paper outlines the principal contributing factors which led to the discovery of the Solomon CID and compares its geology with the Robe and Marillana palaeochannel systems.

Jan 1, 2009

By C V. Deutsch

"Geometallurgical variables often cause problems to conventional geostatistical workflows. There are many variables; some are compositional and some are non-additive. They often show: complex multivariate relationships undersampling relative to conventional grade variables unequal sampling; that is, all variables are not available at all data locations.A variety of approaches have been developed over the years, but geostatisticians remain mostly focused on modelling rock types and a few grade variables with an abundance of data. The problems are reviewed and a chained workflow is presented where appropriate techniques are employed in sequence to permit reliable spatial prediction of geometallurgical variables. The spatial models may be used to assess the value of additional data, for prediction of process performance, for improved mine planning and other optimisation tasks. The chained workflow will include data transformations such as ratios and normal scores that make the variables amenable to geostatistical modelling. Data imputation techniques to account for missing values are considered with special consideration to spatial correlation with the available data. Decorrelation techniques such as the principal components, min/max autocorrelation factors and projection pursuit multivariate transformation are employed to manage massively multivariate modelling. Full distribution modelling must be considered to avoid biases in the prediction of non-additive variables. The post-processing of geometallurgical models must be streamlined for robustness and efficiency. The precise workflow varies according to the specific purpose of the study. Guidelines and thoughts on best practice are presented.CITATION:Deutsch, C V, 2013. Geostatistical modelling of geometallurgical variables - problems and solutions, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 7-16 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By Aiming Z, Shenyi S, Xialei W

Zhangmatun Iron Mine is situated in the suburbs of Jinan city. Shandong, China. Because of surface environmental constraints, no suitable site can he selected to dispose of mill waste. The full mill tailings must be disposed of underground. This paper deals with the work conducted at Zhangmatun mine to develop a total tailings backfill system, taking advantage of a double- shaft blade mixer and an activating agitator to prepare backfill. Cement and ground slag are added to tailings for strength development. Two scopes have been filled and the pillars have been effectively mined out during the field trial. The application of innovative total tailings backfill technology is a new concept at the mine. Detailed planning has achieved a close integration of mining, milling and backfilling. Full mill tailings, with or without rock, are disposed of underground in a continuous process to fill, totally and systematically, the cavities formed by mining.

Jan 1, 1998