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By Falconer A. J

Two magnetic parameters are proposed as a basis for the assessment of ironsands beneficiation. The parameters are deter- mined for raw sand prior to dredging and for magnetic separator head feed over a production period of five months. The relationships between these parameters and the performance of the magnetic separators are examined to establish the value of magnetic assessment compared with the traditional soluble iron assay method. The results illustrate that the first parameter, true magnetic fraction (TMF), has a value superior to that of soluble iron when relating raw sand grade calculated by tri- angulation to magnet performance. In terms of the relationship between magnet head feed grade and magnet performance, TMF and soluble iron perform equally as assessment parameters. For the ironsands mined during the five month period, the second magnetic assessment parameter, composite fraction (CR), is shown to merely reflect TMF and offers no additional information for assess- Ment. Conclusions are that true magnetic fraction has many advantages over soluble iron in terms of time and cost of determination and that it is a meaningful and reliable parameter upon which to base all calculations relating to the mining and beneficiation of ironsands.

Jan 1, 1980

By J Chan, T Baumgartl, A Plante, C Peltre, P D. Erskine

Mine soils are often organic matter and carbon poor due to disturbance, topsoil stockpiling and mixing with spoil. They present an opportunity to observe the accumulation of soil carbon arising from rehabilitation or ‘green carbon’ through organic matter inputs and may be considered for carbon credits. Soil carbon is known to improve multiple soil characteristics and is viewed as an indicator of soil health.When attempting to estimate soil carbon levels in the Australian coal mining regions, both coal and black carbon (BC) need to be quantified. Coalmine soils contain coal particles that are difficult to distinguish from organic matter using standard carbon analyses. BC, a material arising from the incomplete combustion of organic matter and fossil fuels, displays some similar characteristics to coal and is ubiquitous in Australian soils due to bushfires. The presence of coal and BC complicate the determination of green carbon levels in mine soils.A method to quantify coal and BC in mine soils from the Bowen Basin using thermal analysis and multivariate curve resolution is presented. By determining BC and coal contributions it is then possible to calculate green carbon levels in rehabilitated mine soils. Calculated green carbon levels are compared with bulk density as soil quality indicators.CITATION:Chan, J, Baumgartl, T, Erskine, P D, Peltre, C and Plante, A, 2014. Distinguishing carbon fractions in coalmine rehabilitated soils, in Proceedings Life-of-Mine 2014 , pp 491–498 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By B Clements, R Dunne, J Dioses, S Hart

In April 2003 plant upgrades in the æLow GradeÆ Cadia Hill circuit were undertaken in order to improve concentrate quality and metal recoveries from the flotation circuit. The major changes involved: circuit reconfiguration to allow all concentrates to be reground to less than 38 ¦m prior to final cleaning; increasing ball charge in the regrind mill to fully utilise all of the installed power; desliming of the cleaner scavenger concentrate to improve the circuit water balance; and the inclusion of a gravity concentrator in the regrind circuit to recover more free gold to bullion.Once the flotation circuit had stabilised under the new operating conditions concentrate launder modifications and increased froth crowding on the scavenger flotation cells permitted the introduction of stronger collectors without compromising concentrate quality or circuit stability.Twelve months on, the copper concentrate grade has increased by two per cent and metal recoveries increased by three per cent and seven per cent for copper and gold respectively. The project capital outlay of approximately $2.0 million has been repaid in less than three months. This paper will review the project from the design, construction and commissioning perspective as well as the subsequent debottlenecking exercise that was required to eventually yield the full benefits of this upgrade.

Jan 1, 2005

By Landy D. M, Ward M. O, Power W. L

Geological structures are irregular and intricate, so creating a 31) solid geology model is a complicated process. A software system can only partially automate this process, since geological knowledge and experience are required. Therefore, the interaction of a geologist is critical for such a system. This paper discusses some useful advanced functions for enhancing the visualisation and manipulation of 3D solid geology models: flexible attribute display, multiple views, auxiliary display objects, and geologically sensitive operations. It also describes some experiments to explore the effectiveness of these functions and presents sample output. Most existing 3D solid geology modelling systems are implemented in an ad hoc way, which greatly reduces their reusability and extensibility. This paper presents a generic framework for 3D solid geology modelling systems, which is based on object-oriented technology. The deficiencies of current systems may be improved by using this generic framework. A modelling process based on drillhole data is discusses as a case study.

Jan 1, 1995

By Sarracino R. S

A number of ideal detonation codes are used internationally for estimating the strength of explosives compositions. Important and far reaching decisions by explosives users are ofen based on the predictions of these codes, but since different codes can deliver very different answers for the same composition, there is a strong possibility of decision makers being misled. In order to both provide a sensible basis for comparing the theoretical energy from explosives from different manufacturers and to prevent the entire rating system from slipping into disrepute, it is in the interests of all to reach agreement on fundamental criteria used by detonation codes for detemtining strength. The problem is illustrated by a case history and basic conventions are proposed, specifically the adoption of energy of reaction as a fundamental and code independent indicator of explosive energy, and agreement on disclosure by suppliers of key non-proprietary information. These measures would assist explosives customers in assessing the true strengths of explosives from the strengths calculated by the different ideal Codes.

Jan 1, 1990

The concept of æsustainabilityÆ can largely be defined as development that will not compromise the ælivabilityÆ of the planet for future generations. It has multiple dimensions, such as the triple bottom line û environmental, economic and social. And it also includes temporal (now and the future) and spatial (local and global) aspects that have to be taken into consideration to achieve true sustainability.Energy sustainability might be defined as û having the light turn on when you push the switch. It has, of course many more dimensions than this simplistic definition. Coal in Australia has an important role in keeping our lights on, but has its problems that need to be tackled head on to maintain a role in sustainable development.An overriding issue in terms of sustainability for coal is its major contribution to our greenhouse gas emissions. Whilst we have one of the most effective energy sectors in the developed world, based on well-managed, abundant fossil fuels, our greenhouse gas emissions are one of the highest per GDP in the developed world. We have to reduce our ægreenhouse gas signatureÆ.This paper explores the issues of coal utilisation greenhouse gas emissions as an indicator of the fuelÆs sustainability and the potential lower emissions pathways we will have to follow in a future carbon-constrained world.The technology changes will have significant implications for the minerals industry and it is argued that forward-looking coal/greenhouse emissions strategies need to be developed in alliance with the coal (and energy) sector for the minerals industry to maintain its global competitiveness.

Jan 1, 2004

By Cotton P. L

Although the terms "pipe" and "tube" are normally considered synonymous, a distinction is often drawn, the former term being applied to the hot finished product and the latter to cold finished material. It is, considered that the title of this paper includes hot finished seamless, and continuous-weld pipe, cold drawn seamless tubing, and electrically welded tubing.The continuous-weld process will be reviewed first, passing to the various methods of seamless manufacturing, which, in addition to meeting the demand for hot finished seamless pipe, also supply the raw material for cold drawn tubing, the manufacture of which will then be described. Finally the electric resistance-weld process will be Considered, and the paper will conclude with a brief review of the processes described and trends in present-day manufacture.CONTINUOUS-WELD PIPEThe raw material for this process is delivered in the form of coiled, hot finished, strip steel, generally referred to as "skelp". The end of one coil is electrically buttwelded to that of'the next, so forming an unbroken strip. This continuous ribbon of 'steel is fed into a skelp heating furnace, and brought to the correct temperature for the forming and welding operations which follow. This temperature is usually about 1,350°C.The heated skelp issues from the furnace into 'a multistand mill, in which the first pair of rolls is designed to form the skelp into tubular shape, the edges being in close proximity to, but not touching each' other. These edges...

Jan 1, 1951

By H W. Wu, T Harvey

An overview is given of two new developments in mine atmospheric monitoring. A new personal dust monitor (PDM) that gives real-time respirable dust readings is discussed. The unit is mounted within the minerÆs cap lamp battery and internally measures the true particle mass of dust collected on its filter. Samples are available for later mineralogical analysis and results do not exhibit the same sensitivity to water spray as optically-based measurement approaches. The technique achieves microgram-level mass resolution even in the hostile mine environment and reports dust loading data on a continuous basis. The monitor has been evaluated under an Australian Coal Association Research Program (ACARP) grant and is being adopted for statutory mine respirable dust determinations in the United States (US). The monitor has particular application for determining location of high dust sources. It can evaluate the efficiency of engineering means of suppression and other approaches to reducing dust levels. It has been recognised that the PDMÆs unique measurement approach has application to allow real-time atmospheric diesel particulate matter (DPM) monitoring. The industry has no real-time atmospheric DPM monitor at present. Recent surveys in New South Wales and Queensland show significant numbers of miners continue to face full shift DPM exposures in excess of internationally accepted levels. Real-time DPM monitoring will allow the industry to pinpoint high exposure zones where a number of trucks and other vehicles work in areas of poor ventilation. Knowledge of high DPM concentration zones allows efficient modification of work practices to reduce underground minersÆ exposure. Approaches to uses of the DPM form of the monitor and the design of tag boards are discussed. Some outcomes from mine tests with both these new instruments are given.

Jan 1, 2008

By A Winchester, D Grant

The massive 1100 Orebody in Mount IsaÆs X41 Copper Mine has been extracted over the last 40 years form north to south utilising sublevel open stoping methods.De velopment has continually stepped ahead of production to provide access to new primary stoping blocks. The remaining secondary pillars contain stopes with one, two or three fill mass exposures and were constrained by access requirements and stope extraction turnaround time.The remaining southern mining areas consist of large 40 m wide by 300 to 400 m long east-west transverse pillars that have been left to provide access for ventilation and service requirements. Three large transverse cross-cuts or transverse pillars û 4180 x/c, 4010 x/c and the Panel pillar now remain. The 4180 x/c was the last major transverse pillar to be successfully broken.This transverse pillar is being extracted in a retreating sequence, creating 3SLOS stopes due to the surrounding backfilled stopes.In recent years the extraction of the first, and most critical, stopes in the transverse pillars have resulted in large changes to the induced stress field. This paper describes the extraction of the 1.1 million tonne stope P418 in the 4180 x/c pillar.T echnical challenges that were faced and how they were overcome to allow for the successful extraction of the stope are described.Critical to the success of the P418 stope extraction were the rehabilitation methodology used; extraction strategy modifications to address deteriorating ground; mass firings with multiple directional changes; managing the exposure of backfill of variable strengths; and geotechnical monitoring prior to, during and after extraction.

Jan 1, 2005

By D Obeng, D Alexander

Over the past five years, commodity prices have been high and the focus of many plants has been æthe more metal the better, at whatever costÆ. In the recent economic crisis, the focus has shifted more to reducing the cost of production and operating at higher efficiency. Since 2002, JKTech has partnered with the Century mine in north-west Queensland to transfer technology and understanding through the good, bad and ugly economic environments, using methodology and techniques arising from research at the Julius Kruttschnitt Mineral Research Centre (JKMRC) and other research institutions around the world as part of the AMIRA International P9 Project. The JKTech studies were concentrated around the primary zinc circuit. During this period, Century expanded the primary zinc regrind capacity, installed additional scavenging capacity, installed and commissioned a Jameson cell for concentrate cleaning in the carbon preflotation circuit, and installed additional primary grinding capacity. Flotation circuit models were developed for each of the survey campaigns and enabled opportunities for further improvement to be identified, implemented and tested in the subsequent campaign.

Jan 1, 2009

By Tapp B. A

The minerals industry in Australia is currently regarded as the country's economic saviour; the bastion of economic security. As Fitzgerald (1974) stated, 'Australia's natural endowments in minerals are the envy of most countries of the world'. As a result the proposed new mineral developments are on a scale that hitherto in the sixties would have been completely unenvisaged. It is reported that Australia is poised on the verge'of a sixteen billion dollar mining-based investment boom: a boom that will see Australia dominate the energy export field, the mineral processing field, and create the 'coal dollar'. This growth scenario has many inherent dangers, and it is the authors' contention that these should be carefully considered before further development proceeds. Two of the major problems related to the mineral industry growth scenario are the predictability of the future metal market, and the energy cost of mining. The latter problem is the one discussed here. The mining-mineral processing industries in Australia currently use about 36% of Australia's primary energy

Jan 1, 1980

By A Hall, D Kratochvil, P Littlejohn

Economic recovery of gold from complex gold ores, including poly-metallic deposits, is impacted by the presence of cyanide-soluble base metals. These base metals can create both a metallurgical challenge plus waste handling and disposal challenges. Base metals such as Cu and Zn compete for the cyanide reagent and often increase the total cyanide consumption to the point of making precious metals recovery uneconomic. In addition, the accumulation of base metals in cyanide solutions represent a challenge for cyanide detoxification and waste water treatment as these metals report to waste sludge. Such sludge requires safe handling and disposal, with possible long-term liabilities.Base metal interference can be removed with sulfidisation-acidification-recycling-thickening (SART) process technology. SART liberates the base metal from the cyanide complex and precipitates the metal as an insoluble sulfide product that can be recovered as a commercial grade concentrate. With the base metal precipitated, the cyanide can be regenerated as free cyanide and recycled to the gold extraction circuit.BioteQ completed laboratory testing for two projects, one employing cyanide leaching of copper-gold sulfide flotation concentrate and one employing a Merrill Crowe process, to determine the effectiveness of SART to remove and recover Cu and Zn in high-grade sulfide concentrates and to reduce the impact of cyanide-soluble metals on gold recovery and cyanide consumption. This paper will provide an overview of the testing methodology and results along with a review of the potential for SART to be applied to complex gold ores with poly-metallic deposits to improve project economics, operability and waste management.CITATION:Littlejohn, P, Kratochvil, D and Hall, A, 2013. Sulfidisation-acidification-recycling-thickening (SART) for complex gold ores, in Proceedings World Gold 2013 , pp 149-156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Behl S

Flocculation behaviour of six different dolomite samples, four from the Florida mining district, one from Perry, South Georgia and another from New Jersey was examined using polyethylene oxide (PEO) as a flocculant. The samples were similar in chemical composition, however the porosity of the samples from the Florida mining district was higher than the others. FT-IR, adsorption and surface modification by leaching revealed that flocculation was directly related to the presence of isolated hydroxyl groups on the surface. The adsorption mechanism was believed to be hydrogen bonding of the ether oxygen of PEO with isolated -OH sites on the solid.

Jan 1, 1993

This paper has been developed for æThe Race for SpaceÆ conference. It ranges over various aspects, all of which are within the umbrella of marketing. The question is posed because many engineers, tunnelling and other specialisations, frequently demonstrate an unwillingness to embrace marketing. The accurate reply is probably à ænot an engineer!Æ The paper identifies some of the possible explanations for this reply. The vast majority of the themes, ideas and principles are based on more than 25 years actual experience for the author with Engineers, Tunnelling and other disciplines. This experience has been gained with leading consulting engineering practices; some of the worldÆs largest construction contractors together with other organisations employing engineers in the public, private and tertiary sectors in the UK; US; Europe; the Middle East and throughout Australia and New Zealand. Experience has been gained in design offices; head offices and construction job sites in four contrasting continents. The most significant themes developed throughout this paper are as follows:æLetÆs go and do some ærealÆ work and leave the marketing to others!ÆæMarketing is just a æsoftÆ option and neither technically based nor true management!ÆNIMBY-ism (Not In My Back Yard) so leave well alone!Engineers regularly confuse services marketing -v- product marketing à a useful cop out, or a genuine cry for help?Marketing databasesæLetÆs get rid of the term æsellingÆ and replace it with the more acceptable à and less distracting for tunnelling engineers à 'marketingÆDistinction between benefits and features à in The Race for SpaceSales Comprehension Test, Benchmarking TestJack WelshÆs æmost difficult decision for a CEOÆHarvard Business ReviewÆs (HBRÆs) formula for performanceMany engineers are losing the balance in their lives Sustainable development and engineering æQuality work doesnÆt mean quality serviceÆMajor recommendationsRecommended references

Jan 1, 1999

In 1984/85 financial year Australia produced 529 thousand barrels per day (kbd) of crude oil. By far the major contribution (453 kbd) was light waxy oil from offshore Gippsland, Victoria. When these discoveries were made in the latter 1960s, imported oil was available in abundant supply and at low prices. Because of this, the Gippsland producers persuaded Government to control the marketing and pricing of their crude, and thus provide the required security of offtake. Political events in the middle East created supply shortages during the 1970s, and dragged up government selling prices for OPEC crude oil. Thus Arab Light crude that sold for less than US$2/barrel (bl) in 1970 reached $34/bl in 1981. Following the consequent decline in world oil demand, in 1982, Australian refiners sought to evade their obligation to lift Gippsland crude. Hence, in 1983, the Government was forced to introduce a floor quota of 385 kbd of Gippsland crude liftings and to allow producers to export any additional production refiners did not require. On expiry of the old arrangements, Government introduced a partial free market from January 1985, whereby the balance in excess of 350 kbd may be sold to Australian refiners at negotiated prices, or exported as before. In 1984/85 exports were some 90 kbd and will be higher in the current year. About half this total has been exported by BHP, providing valuable experience and lessons which are described in the paper.

Jan 1, 1986

By D Cooke

In 2010, Kalgoorlie Consolidated Gold Mines (KCGM) was Australia’s largest gold producer, with total annual production of 788 000 ounces. Of the gold produced by KCGM in 2010, 95 per cent was extracted from the Fimiston open pit, also known as the Superpit. The Fimiston operation encompasses the historic Golden Mile, from which more than 55 million ounces of gold have been extracted from the world-class Fimiston lode style mineralisation.The operational performance of the KCGM Fimiston open pit was reviewed for the period between 2005 and 2010. Key performance metrics reviewed included mined tonnes and grade, cost per ounce of gold produced and the mine to mill reconciliation trends. The years 2007 and 2008 were characterised by a decline in performance against key performance metrics. The ore zones were diluted, with the excess tonnes mined resulting in lower grade and an increase in the cost per ounce. Poor reconciliation between ore mined, the ore reserve model and the grade control polygons was also observed.A series of improvement initiatives were implemented in late 2008. As a result of changes made to the grade control and mining practices, the site performance recovered. Unplanned dilution was reduced, which had a positive impact on mined grade. The lower tonnes combined with higher grade reduced the cost per ounce to below budgeted levels in 2009 and 2010, enhancing the profitability of the operation. The operational performance between 2005 and 2010 was compared to the turnover statistics for the KCGM geology department over the same period. Turnover accelerated between 2005 and 2007, peaking at an annualised rate of 43 per cent. With the onset of the Global Financial Crisis and the implementation of retention initiatives, turnover reduced significantly between 2008 and 2010. A strong consistent correlation was observed between the turnover trends in geology and the performance of the grade control function and resultant site metrics.The cost of turnover is known intuitively, however, rarely quantified. To evaluate the benefit of the improved performance, a detailed financial model was used to quantify the impact of the grade control function. In 2010, the headgrade exceeding budget by just four per cent contributed an additional A$24 M of value to KCGM. In contrast, if the 2008 performance had been replicated in 2010 (-9 per cent on headgrade), the result would have removed A$61 M in value from the business. The KCGM experience between 2005 and 2010 demonstrates the value of human capital in a mining operation and the importance of a high performing geology grade control team to the profitability of a mining operation.

Aug 22, 2011

Rope guides, consisting of ropes spanning between anchor points at the top and bottom of shafts, have frequently been considered as a viable alternative to fixed guides, comprising buntons and guides. However, their design has generally been based on empirically derived rules, arising from European hoisting practice of 50 to 100 years ago. This paper describes a recent technology development project aimed at defining and quantifying the important forces acting on rope guided conveyances, calculating the resulting displacement of the conveyances and assessing whether the displacements are acceptable or not. The paper describes the derivation of aerodynamic force coefficients based on CFD analyses and other significant forces acting on the conveyance and rope system. The conveyance displacements may be calculated using computer simulation of the mechanical system, or approximately using simplified equations given in the paper. Measurements taken to confirm the suitability of the proposed formulation are described. The combination of displacements and assessment of the rope guide system design are proposed, based on the ratio of design clearances and the predicted displacements.

Jan 1, 2005

By Ward C. W

Conventional polygonal and block modelling techniques inadequately represent the grade-thickness distribution of some narrow shear and stratabound gold deposits. The polygonal influence of high-grade drill intercepts can result in overestimates of resource tonnages at high-grade cut-offs. Although block modelling methods provide grade smoothing and a better representation of structural continuity, the technique can lack precise definition of ore width. An alternative method known as Spatial Object Modelling (SOM) has been developed on MineMap software to overcome some of these modelling issues. This method does not rely on a uniform cell size and allows grade smoothing between resource intercepts in three-dimensional space. The SOM technique creates grade-thickness bars on regular, user-defined spacings which allow easy visual comparison of raw intercept data to the interpolated model. Model cell values are readily transformed into isopachs, isopleths and resource perimeters for reporting and mine planning purposes.

Jan 1, 1997

This problem is seen as being central to a number of peripheral problems. Of these, the following are considered to be of major importance: 1. Reserves. Changes in Quality. Depths at which they occur. The effects of catchment and water storage areas. The effects of urban development. 2. Environment and the compat- ibility of mining and preparation of coal. 3. Transportation of Coal. J. tabour.

Jan 1, 1976

Comminution Kinetics equations are developed to take into account difference of grindability of mineral components. The equations describing both batch and closed circuit grinding or crushing processes are given. These equations are applied to industrial data to derive comminution kinetic and classification characteristics of the component minerals in a multi-mineral ore. Control strategy based on these concepts is presented.

Jan 1, 1985