Search Documents

Beneficiation of Nickel Lateritic Ore from Montes Claros de Goißs, Brazil Beneficiation is a key factor for both technical and economical aspects of industrial processing of nickel lateritic ores. A combination of comminution, classification and concentration stages are usually used to upgrade the metallurgical plant feed, thus resulting in both capital and operating cost reductions. This paper describes the testwork conducted on Montes Claros nickel lateritic ore in order to investigate the potential for upgrading. A comprehensive laboratory testing program included crushing, scrubbing, screening, grinding, gravity separation and attritioning, for both saprolitic and limonitic ore types from the Montes Claros deposit. The results indicated a clear potential for such an upgrade, which was later validated in a pilot plant program.

Sep 13, 2010

By P J. Vardon, L A. van Paassen, Y Yao, A F. van Tol

Thin-lift atmospheric fine drying (AFD) is a technique used to dewater mine and oil sand tailings, which utilises both self-weight consolidation and atmospheric evaporation. The disposed layers undergo a cyclic drying and rewetting process due to precipitation and deposition of additional lifts on top of the dried layer. The current research aims to optimise the deposition process via use of a numerical model and realistic atmospheric conditions, including both periods of drying and wetting. The model is based upon water balance and includes large strain considerations. A number of material behaviours are characterised using empirical fitting curves based upon laboratory measurement of material characteristics, including both the shrinkage and water retention curves for drying and rewetting. The model is able to model multiple lifts, simulating field scale and realistic climatic conditions within timescales suitable for engineering practice (eg seconds or minutes). The model has been previously validated against controlled laboratory experiments and utilised to simulate field tests. A series of simulations are presented to illustrate the ability of the model to be used as a practical tool for the optimisation of a tailings deposition strategy.CITATION:Vardon, P J, Yao, Y, van Paassen, L A and van Tol, A F, 2015. The use of a large-strain drying and consolidation model to optimise multilift tailing deposits, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 263–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

The mercury, gold, silver, copper, lead and zinc values of soils over altered and mineralised rock were determined to establish the potential use of mercury as an indicator element in geochemical prospecting. The results are presented to show that mercury can be used successfully in prospecting for precious metal mineralization in the Thames-Waihi area.

Jan 1, 1979

By Sulanto J, Talonen T

In the mid 1960's Outokumpu considered building a lead Flash Smelter on the basis of Flash Smelting technology developed first in the late 1940s for smelting copper concentrates. Pilot scale tests were carried out and the process was found technically sound. The project was however not economically viable under Finnish conditions and it was cancelled. In 1981 pilot plant tests were restarted after many enquiries from the primary lead producers. All the know-how and development made in copper and nickel smelters was applied to the Lead Flash Smelting process and the tests were successful. Outokumpu has so far tested several types of lead concentrate with lead contents ranging from 28 to 75 per cent. The concentrate is oxidized and smelted to metallic lead and slag directly in the Flash Smelting Furnace using high oxygen enrichment of tonnage oxygen. Fossile fuel is used in the Flash Smelting Furnace in cases when the feed material does not contain enough latent heat to smelt the furnace products even though pure oxygen is used for oxidation. Thus the process results in a low consumption of extraneous energy. Use of oxygen results in a small gas flow but it is rich in sulphur dioxide. The gas treatment facilities and sulphur recovery plant will be small in size and low in investment cost. The process is flexible and can produce stable quality of products from different types of raw materials. Quality of lead bullion especially the sulphur content can be regulated over wide a range, from 0.1 per cent upwards according to the needs of the refinery.

Jan 1, 1984

Spectroelectrochemical Investigation of Hydroxamate Reagents on Copper Oxide Minerals

Sep 13, 2010

It is a great honour to address our Institute as President, but the choice of a suitable subject was not an easy one. In the past when the presidential address was given at an annual conference the subject usually related to the conference or industry concerned; more recently the subjects have been more philosophical and this is a distinct advantage to me.I appreciate that I am addressing an informed audience and I am sure' that you are well advised in many of the points that I hope to leave with you. Unlike the specialist who gets to know more and more about less and less and eventually knows everything about nothing, I am one of the group who gets to know less and less about more and more and eventually knows nothing about everything.I hope you will appreciate this point whilst you are listening to me.In recent years I have been closely associated with the problem that troubles most governments of our time: the competition of many groups of differing backgrounds for the land that is available to the nation.This is of particular interest to the industry with which we are concerned as it is of critical importance to the discovery and development of future reserves of minerals and metals. Part of my daily task is involved with the administration of legislation for mining operations and the conditions under which such operations may be undertaken, in implementing government policies relating to mining, and in designing and administering legislationdirected to safety and health in mines.Most of our members are involved in exploration or in day-to-day problems associated with the production of minerals or the management of companies in these pursuits and would be aware of many of the conflicting viewpoints on priorities.F. F. Espie in his presidential address of 1975 'On being a minority', made the point that our Institute found that the mining industry had a great communication 'Problem with the Australian people.I believe that this is one of our major problems.

Jan 1, 1977

THE slide-rule, as a quick and convenient instrument for performing approximate calculations, is steadily growing more and more into favour with the engineer, and results obtained by it are considered close enough to enable him to satisfactorily dealwith a considerable portion of his work. To the surveyor, however, whose ordinary computations must be as precise as his measurements, the present makes of rule are insufficient, except for a very narrow margin of the scales and for rough work. Few will carry the rule when they can clearly see that it is unreliable for general routine, and the careful surveyor is inclined to look askance at those who do use it, recognizing the temptation there undtmbtedly must be to push it into work that the log book should be called upon to treat. From the fact that a surveyor's duties take him on the surface in all weathers, and underground in many wet and uncomfortable places, where the manipulation of a book of mathematical tables becomes both awkward and patience-trying, an efficient slide-rule must offer the mbst transparent advantages. Again, a surveyor being specially trained to read divided scales quickly and accurately, the slide-rule must commend itself as an apt addition to his outfit.

Jan 1, 1912

The history of mining is rightly proud of its achievements in improving productivity and cost improvements over the years. No matter what measure is used, tonnes per manhour, cost per tonne, etc vast improvements have been made over the last hundred years. In fact over the last ten years in Australian coal mines raw coal output per employee has increased by 60 per cent. When one examines why these improvements have taken place the principal reasons have been technological advancement in mining equipment, excavator and dump truck capacity increases, longwall and continuous miners continually improving in reliability and size. Of course all these improvements are correlated to an increase in capital cost. Even with the above-mentioned advances the pressure for increased performance is as strong as ever. The international mining and mineral-processing sector is currently operating in a recessive market with some traditional commodities, eg gold trading at 20 year lows. During recessive times senior management will demand greater returns on capital employed: the obvious choices being reducing costs or increasing throughput. In addition, head office environments will often place a capital freeze on operational management so the opportunity to take advantage of technological change is not available. The challenge is, therefore, to increase throughput and cut costs without the need for capital. The answer is to optimise the existing labour and plant. If done systematically a result in productivity improvement, in our experience, as high as 45 per cent can be achieved with the average across South East Asia and Australasia being 21 - 23 per cent. The intention of this paper is to present a systematic approach to labour and machine utilisation thereby gaining the greatest possible return on the existing capital base.

Jan 1, 1999

By E Thomas, L McCallum, G Dale, J Bennett, K Reardon-Smith, S Raine

Sustainable closure of coal mines in Australia to a safe, stable, non-polluting condition remains one of the industry’s biggest environmental and social challenges. A significant proportion of mines in the Bowen Basin of Queensland have dispersive spoil. Based on an estimated area of 20,000ha and a rehabilitation cost of AUD$100,000 to AUD$150,000/ha, the instantaneous rehabilitation liability for the Bowen Basin alone is estimated at AUD$2 to $3 billion.Dispersive spoils present problems in post-mining rehabilitated landforms due to increased potential for surface and tunnel erosion, compromising the ability to achieve fundamental mine closure objectives of a safe, stable, non-polluting and self-sustaining post-mining landform (Minserve, 2004). Dispersion results in clay particles being mobilised and transported in water, even at low flow velocities (So et al., 1998; Minserve, 2004), and blocking of soil pores, resulting in surface sealing, crusting and reduced permeability (DNR, 1997; Vacher et al., 2004) which, in turn, further increases runoff (Dang et al., 2018).CITATION:Dale, G, Reardon-Smith, K, Thomas, E, Bennett, J, McCallum, L and Raine, S, 2018. A process-based approach to mine rehabilitation decision making using Bayesian modelling and risk-based principles for dispersive spoil rehabilitation, in Proceedings Life-of-Mine 2018, pp 106–109 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By A Radici, S Russell

The Dampier Port Upgrade was completed in 2007 and is the largest project in Rio Tinto Iron Ore's expansion program. The project doubled Dampier Port's iron ore shipping capacity over a five year period. Sinclair Knight Merz (SKM) was appointed by Rio Tinto as the Engineering, Procurement and Construction Management (EPCM) contractor to manage Phase A and Phase B of the Dampier Port Upgrade. The aim of the project was to increase the Dampier Port capacity from 74 to 140 million tonnes per annum (Mt/a). This increase in shipping capacity tripled the capacity of the Parker Point facility from 34 to 94 Mt/a, whilst the East Intercourse Island facility increased from 40 to 46 Mt/a. The Dampier port remained fully operational throughout construction and achieved record yearly export tonnages over the period of the project. The $US1.4B project was completed ahead of schedule, on budget and with an outstanding safety record. Significantly the project team set an industry benchmark by achieving five million man-hours Lost Time Injury (LTI) free. The project has been recognised by the Engineers Australia 2008 Western Australian Engineering Excellence awards as category winner in resources and the overall winner in WA, and went on to win a National Engineering Excellence award. This paper provides an overview of the EPCM project management and an insight into some of the key drivers that have delivered this outstanding project.

Jan 1, 2009

By J Jasper, L Koroznikova, J Begelhole

This paper outlines a comparison of heavy liquid and heavy suspension separation methods for iron ore characterisation.As part of Arrium MiningÆs program to improve its knowledge of ore types being processed in its two hematite ore beneficiation plants (OBP), metallurgical evaluation of hematite feed for the upgrading process has become a major focus.Iron ore deposits almost always contain more than one valuable (and relatively dense) iron mineral. Iron ores are found with a range of iron contents, giving rise to density variations.At present the industry relies on heavy liquid separation techniques for the evaluation of iron ore samples arising from exploration, mining or metallurgical processes. There are only a few high-density liquids available, which are both high-cost and highly toxic.Low-toxicity solutions that can be utilised at relative densities up to 3.0 have been developed. However, highly-toxic organic liquids are required presently to achieve relative densities beyond 3.0.Bromoform which has a specific gravity (SG) of 2.89, and diiodomethane (SG 3.31) are commonly used; both present significant health and safety hazards.æClericiÆs solutionÆ (mixtures of thallium formate and thallium malonate) provide liquids having specific gravities between 4.0 and 5.0. ClericiÆs solution is highly toxic and testing is currently conducted by a limited number of laboratories worldwide.An alternative to ClericiÆs solution and organic liquids is a low-toxicity, high-SG, suspension technique, which has been demonstrated successfully for heavy mineral sands. This heavy suspension method employs mixtures of fine tungsten carbide particles in lithium heteropolytungstate (LST) solutions.Heavy liquid separation is not commonly used as part of routine iron ore feed characterisation due to the expensive, toxic and time consuming nature of the technique. Our results show that the heavy suspensions method can achieve low-cost, low-toxic separation and are outlined and results compared with results using ClericiÆs solution presented.Heavy suspension technique provides a theoretical/absolute separation of a particular sample. By placing an iron ore sample in a suspension of a particular density, it produces two products: a sink fraction and a float fraction. As iron oxides-hydroxyoxides are denser than the gangue minerals associated with the ore, particles that have high iron content will sink and the particles with gangue association will float. This process is repeated over several densities, thus also enabling separation of the constituent iron ore phases. A theoretical grade and a theoretical mass recovery can be calculated. With these calculations, a grade-mass recovery curve can be constructed for any element that is of interest.This type of characterisation can be used to either prepare OBP feed-piles of known processing characteristics, or to benchmark the performance of the process against what can be theoretically achieved on a continuous basis.CITATION:Begelhole, J, Jasper, J and Koroznikova, L, 2013. Application of the heavy suspension technique for ore beneficiation plant feed characterisation from the Southern Middleback Ranges, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 269-278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Jones S. C

A specific arc can be cut in hard rock formations using a specially designed multistep piloI bit, variable sized drift joint and long heavy control rod as a stabilizer rather than the Vaughan Thompson "Lifting" arc cuttingequipment. The rate of deflection can be controlled after an initial determination of behaviour in any particular rock type.

Jan 1, 1966

By M Humphreys

Multi-episodic mineralisation is often characterised by different spatial trends exhibited by different generations of the mineralisation. The structural complexity of mineralisation together with the heterogeneous nature of the mineralised zones prevents unambiguous application of the conventional deterministic methodology for 3D constraining of the mineralised domains (ie conventional wireframing is ambiguous).A different approach, discussed in the present paper, includes a probabilistic definition of the domains encompassing one statistical population of the data. The domains are defined geostatistically using the indicator probability model. An indicator threshold is chosen for the definition of the high and low-grade domains. The spatial distribution of this indicator is then modelled by a variogram. The probability of exceeding the given grade threshold is than estimated by ordinary kriging for each modelled block. Blocks are then grouped according to their probability of exceeding the threshold and a continuous closed volume (domain) created from this likely patchy grouping using an appropriate structural model to fill the gaps). Methodology for the geostatistically assisted domaining is discussed in the paper. It is suggested that this technique represents an additional tool facilitating a structural interpretation of the mineralised zones.After the geostatistical domaining of the lode has been completed the grade within each of the domains is modelled using Uniform Conditioning method. Application of Uniform Conditioning for modeling the grade distribution has a significant advantage over linear methods (such as inverse distance or kriging) because Uniform conditioning enables estimation of local recoverable resources at different selective mining unit sizes that can be substantially smaller than the drilling density and are unable to be estimated directly.

Jan 1, 2002

By G R. Hancock, D Verdon-Kidd, M J. Saynor, J B. C Lowry, T J. Coulthard

The ability to simulate the stability of post-mining landscapes over time scales ranging from decades to millennia is a critical element in the assessment of closure designs for uranium mines. Landscape Evolution Modelling (LEM) technologies provide a means to simulate and assess the long-term geomorphic stability of a conceptual rehabilitated landform for periods of thousands of years. However, a major issue with simulations derived from long-term modelling are the limitations associated with the data inputs. Specifically, simulations which utilise historic rainfall data only represent the variability of rainfall events that have occurred over a relatively short period. Consequently, these simulations run the risk of not accounting for the full range of rainfall variability that might be expected over an extended period of up to 10 000 years. Therefore, for this study a probabilistic approach was adopted to generate a stochastic synthetic rainfall data set to produce a series of unique rainfall scenarios, each representing a simulated period of 100 years. Importantly, utilising such an approach allows uncertainty in predictions to be better accounted for and provides a range or probability of likely outcomes.In this study, the effect of ten individual rainfall scenarios are assessed in terms of their impact on the predicted erosion and denudations rates produced by the CAESAR-Lisflood LEM for a conceptual rehabilitated landform of the Ranger Uranium Mine (RUM) in the Northern Territory of Australia, focusing on the Corridor Creek catchment (Figure 1). While legislation requires this site to be erosionally stable for at least 10 000 years (Commonwealth of Australia, 1987), here the focus is on the first one hundred years of landscape evolution, as this is the period in which erosion is expected to be higher, with limited vegetation cover or pedogenic development in the initial decades after rehabilitation. It is also the period where the drainage pattern is set.CITATION:Lowry, J B C, Verdon-Kidd, D, Hancock, G R, Saynor, M J and Coulthard, T J, 2016. Application of synthetic rainfall data to long-term modelling of a rehabilitated landform, in Proceedings Life-of-Mine 2016 Conference , pp 75–79 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By D Reid, A Fourie, J Ayala

This paper discusses cone penetration test correlations for loose gold tailings that were developed within a critical state soil mechanics framework. The development of a new calibration chamber for cone penetration testing that consists of a modified triaxial cell is described. Some of the early development and commissioning issues that were encountered, as well as the solutions adopted are outlined, including the system to prepare the samples and to acquire high-quality data from the testing. Also, the triaxial laboratory testing required to achieve the critical state line is described, including some of the basic precautions considered necessary as good practice. Additionally, the system adopted for volume tracking of the calibration chamber sample is described, which is essential for ensuring a reliable state parameter comparison against the acquired cone penetration test data. Finally, some laboratory test data from the calibration chamber is plotted against the soil behaviour type charts currently available from various authors.

Jul 1, 2021

By H Ş. Duzgun

It is expected that the future of mines will heavily adopt autonomy. However, problems with leveraging workforce transition, meeting Sustainable Development Goals, SDG’s (poverty, reduced inequalities), managing uncertainties (geologic, operational, economic), cybersecurity (connectivity, cyber-physical infrastructure) and innovation (transformative processes, real-time decision-making etc) are required to be solved for the intended autonomy. These problems also impact the safety of the future mine environment. The AI technologies provide a broad range of opportunities for enhancing mine safety. However, development of an accurate AI model for mine safety requires a large number of data, which may not be readily available to overcome the associated uncertainties in the mine environment.

May 5, 2022

The Application of Roasting Pretreatment for Antimonial Refractory Gold and Silver Ores

Sep 13, 2010

By the use of flotation tests it was confirmed that there are two functions of oxygen in sulphide mineral flotation. Sized samples of galena and chalcopyrite were sulphidized, washed free of excess sulphide ion, and then contacted with air-saturated water for certain lengths of time. The mineral was then transferred to a sealed laboratory flotation cell containing water with a known concentration of dissolved oxygen. Xanthate and frother were added and flotation continued for 1 min.Both the extent of mineral oxidation and the concentration of dissolved oxygen markedly affected the flotation of galena and chalcopyrite. The response to a change in either variable is dependent on the level of the other, but generally best flotation occurs with the maximum degree of air saturation of the pulp. Galena flotation is hindered by oxidation of the mineral beyond a small threshold amount but a similar effect for chalcopyrite was not observed...

Jan 1, 1967

Silica reacts with cryolite at 1010°C in two stages. The first stage is the formation of a sodium aluminosilicate of composition consistent with the mineral jadeite (Na20.AI20s.4Si02). The formation proceeds by atleast two different reactions. Formation of alumina or an aluminosilicate proceeds to its limiting value in the first 30 min while the formation of jadeite proceeds at a steady rate until quantitative conversion is achieved after 150 min. The net overall reaction can be expressed by the equation 6 Si02+2 Na3AlF6? (Na20.AI20s.4Si02) +2 SiF4 +4NaF.The second stage involves a slow reaction that proceeds with the evolution of a little SiF4, The net result is the formation of sodium aluminosilicates that are soluble in 30 per cent AlCIs-HCI solutions. While this could be explained by disproportionation of jadeite to form albite (Na20.Al203.6Si02) and nepheline (Na20. AI203.2Si02), it is more likely that it is due to further but limited reaction between the oxides and fiuoroaluminates.

Jan 1, 1972

Geological modelling is a crucial preparatory stage to most facets of the mine planning of an orebody. The process of modelling involves skilled geological interpretation. Recent innovations in computer software and graphics hardware provide many tools which can be used to dramatically improve on manual methods of interpreting orebody data. Geological interpretation can be carried out quickly to produce accurate block models for many orebody attributes, such as grades, and these models can be easily updated locally as exploration and mine development data become available. The speed of the modelling process coupled with the mass storage capabilities of the computer now allows geologists to optimise the geological model or carry more than one model through to the mine planning phase.

Jan 1, 1987