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Separation of Iron Particles from Banded Haematite Quartzite (BHQ) Ore by Selective Magnetic Coating The separation of fine iron particles from banded hematite quartzite (BHQ) has been studied using selective magnetic coating. The BHQ ore assays as 38.9 per cent Fe, 42.5 per cent SiO2 and 1.0 per cent Al2O3. Mineralogically, the ore contains hematite and quartz as the major mineral phases where as goethite and magnetite is present in minor entities. Natural magnetite of very fine size and oleate-magnetite in colloidal form, prepared synthetically in the laboratory are used as the coating material on the surface of hematite particles. The selective coatings of oleate-magnetite on BHQ surfaces followed by magnetic separation studies have indicated that, it is possible to achieve 62.3 per cent Fe with 8.5 per cent SiO2 at 85.4 per cent iron recovery. The recovery of iron values is found to be superior in comparison to the conventional magnetic separation techniques. The selectivity of coating for enhancing the magnetic response of iron particles is achieved by controlling the surface properties of the particle via electrokinetic potential adjustment by controling pH and addition of oleate-magnetite. In the separation process, the effects of pH, magnetic intensity and addition of oleate-magnetite are studied to achieve the maximum grade and recovery of iron values. The optimum separation is observed at pH of 7.5, oleate-magnetite concentration of 0.25 ml/g of BHQ ore and a magnetic intensity of around 0.8 Tesla. The X-ray diffraction (XRD), Infra-red spectroscopy (IR) and UV-visible spectroscopic studies strongly suggest preferential coating of magnetite on hematite surfaces. Scanning electron microscopy (SEM) studies have brought out the semi-quantitative features of BHQ ore. The recovery of iron values from a lean grade ore such as BHQ is carried out looking into the future needs of this ore in India for iron and steel making.

Sep 13, 2010

Preliminary work being undertaken on the optimisation of decision strategies for an open-pit metalliferous deposit is presented. The Optimal Control method has been selected rather than the easier to implement Dynamic Programming method of optimisation since a fundamental criteria of Dynamic Programming is violated. Essentially a system of state equations and decision variables is developed for the operation under consideration.

Jan 1, 1984

Promoters for Soap Flotation of Phosphate Minerals

Sep 13, 2010

By G J. Corbett, P Magner, M McKenzie

Structures formed during ductile deformation have been reactivated during the later brittle mineralisation process. Two generations of folding are classified as: early recumbent megascopic FI folds and FI shears which transpose the hinge regions, and later upright F2 folds. S1 is folded about F2 folds which contain axial planar S2 crenulation cleavage. Vergence relationships between S1 and bedding indicate that many of the mineralised structures occupy sites of FI folds which have acted as plumbing systems for later gold mineralisation (eg Blackwater mine). The Globe-Progress gold mineralisation is localised by a major jog formed by sinistral strike-slip movement on two FI fault segments and mineralisation also occurs in smaller jogs along strike (eg Sir Francis Drake, Happy Valley-Merrijigs, Cumberland).   The lodes of ribbon quartz which exploit the FI shears and local bedding planes, are inferred to have mostly formed after the peak of metamorphism, possibly related to the emplacement of Carboniferous granites. This was followed by a sequence of vein deposition and wallrock alteration which consists of quartz-As/Fe sulphides ? carbonate - stibnite ¦ trace base metal sulphides and Bi-sulphosalts ? illitic clay/sericite-chlorite. Gold at Globe-Progress is mainly encapsulated in arsenopyrite. At Blackwater, free high fineness gold occurs in partings in lode quartz with late sericite-chlorite. The above sequence of events is comparable to that encountered in many intrusion-related gold systems throughout the Southwest Pacific region. There is a spatial relationship between gold mineralisation and dykes variably described as diabase, dolerite or lamprophyre. Alkaline rocks occur in many Pacific rim and older goldfields and may possibly be related to a magmatic source for gold mineralisation.

Jan 1, 1997

Two outstanding features of the world's young orogenic belts are their very consistently developed suites of volcanic rocks and, it is now recognized, the rather distinctive types of mineralization they contain. Further,it is now known that these volcanic suites exhibit evolutionary patterns, and it is beginning to appear that this evolution in style of igneous activity is accompanied by a parallel evolution in style of mineralization. Specifically,podiform chromite and stratiform pyritic copper ores of Alpine ultramafic/submarine tholeiite association progressively give way to more zincian stratiform ores associated with andesites and dacites, "porphyry copper"deposits developed in quartz dioritic to dacitic plugs, and lead-zinc stratiform ores related to increasingly pyroclastic, rbyodacitic volcanism.This "coupling" is exhibited well in the volcanic arcs - the young orogenic zones-of the SW Pacific which, with tbeir abundance of youthful and commonly unmetamorphosed materials provide an opportunity for investigating, through a petrochemical approach, the possible significance of ores in the elucidation of mechanisms of lava formation. It is suggested as a working hypothesis that in the orogenic (voleanic arc) regime ores are associated with the cale-alkaline rocks because these cale-alkaline rocks are in part generated by exhalative loss, and the ores are among the manifestations of tbat loss.

Jan 1, 1978

By M S. Powell

In this paper it is argued that we are entering a new mining era, based on considerably more challenging orebodies as we rapidly expand minerals production by exploiting previously uneconomic deposits. Rapidly increasing production costs cannot be sustained by continually increasing commodity prices, as illustrated by the recent downturn in the industry.Driven by reduction in grade, requiring the processing of 50 to 100 per cent more ore to recover the same amount of metal, often accompanied by finer grain structure - necessitating a finer product size and more challenging recovery - the productivity of the mining industry is dropping in real terms. The author suggests that tweaking current technologies and relying on economies of scale will not turn the industry around, but rather a switch to considerably more efficient processing is required.It is imperative to utilise the properties of the orebody, especially in terms of variability, in revolutionising our processing techniques. Our new mantra may be æselective mass mining with flexible processingÆ. This paper explores how this may be implemented using current technology and equipment in order to change the cost profile of the new mining industry. Orebody knowledge, based on the underlying process drivers, rather than proxies, is required. These properties and their variability will need to be propagated into the orebody through utilising the geological data rather than smoothing block averages, which destroys information on variability.Novel flexible circuit designs are presented that can respond to a wide variability in ore properties and throughput requirements in order to slash processing costs and energy utilisation, while enhancing overall recovery. The success of these circuits will be based on an ability to predict at both design stage and in everyday processing the variable ore properties, which is dependent upon reliable orebody knowledge that caries variability and underlying processing properties.CITATION:Powell, M S, 2013. Utilising orebody knowledge to improve comminution circuit design and energy utilisation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 27-36 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By K Williams, W Chen, J Miller

The flow function of an iron ore material governs its flowability characteristics in material handling chains within the resource industry. A uniaxial compression test is able to obtain a flow function more rapidly comparing to the Jenike direct shear test; nevertheless, the results often exhibit lower rankings using the former method. This study aims to investigate the fundamental stress states within the test specimen that lead to this phenomenon, and to introduce a new uniform density specimen preparation method for a uniaxial compression test, in order to achieve comparative flow functions as for a Jenike direct shear test. The minimisation of the wall friction effect and achievement of the critical state when preparing a uniaxial specimen are explicitly discussed. Experimental investigations on flow functions of a suite of Australian iron ore samples were conducted using both the uniform density uniaxial compression test and the Jenike direct shear test. Results from both methods were found to be comparable, providing the specimen exhibits cohesive flow behaviours. The outcome of this research enabled development of a rapid and reliable flow function testing method for cohesive iron ore materials.CITATION:Chen, W, Williams, K, Roberts, A and Miller, J, 2017. Rapid and reliable flow property testing – a modified uniaxial approach, in Proceedings Iron Ore 2017, pp 149–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Old Copper Flotation Tailings Waste Reprocessing

Sep 13, 2010

By R A. M Maddever, P Jeanneau, V Flahaut

Over the entire life cycle of a mine, from early resource evaluation to the blasting of benches, the collection of geochemical data is crucial for the site operator, who must routinely and intensively drill and sample the orebody. This produces huge numbers of physical samples, in turn requiring significant cost and time for their preparation and assay. Moreover, despite best efforts, the sample recovery process is prone to error, which limits the quality of data.The pulsed neutron gamma technique has been used for decades in various industries, in particular oil logging, for its ability to provide direct identification and quantification of elemental concentrations. However, its implementation in logging tools for the mining sector is relatively recent. Built around the latest in technology for optimal spectrometric measurement, a commercial tool referred to as FastGrade™ 100 has been available for a few years and used with increasing success in the mining environment, specifically the iron ore industry, resulting in a reduction in the amount of collected samples. Relying on the physics of neutrons and gamma photons, both of which are particles that penetrate the surrounding bedrock through several tens of centimetres, such spectroscopy tools measure in real-time the composition of a much larger volume than the delimited volume of the drilled material traditionally used for geochemical mapping. Better statistics and reliability of the estimated composition increase the ability to properly and quickly measure drilled holes and allow the substituting of all or part of the sampling and assaying efforts by geochemical log data. Our paper focuses on this technology, known as pulsed fast and thermal neutron analysis (PFTNA). It reviews the main drivers for the design of such a logging tool and discusses how the fundamental characteristics of the technology, in terms of neutrons and gamma interactions, translate into interpretation of the analytical output.CITATION:Jeanneau, P, Flahaut, V and Maddever, R A M, 2017. Iron ore benefits from neutron pulsed geochemical tools, in Proceedings Iron Ore 2017, pp 387–396 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Maghemite - A Source of Heavy Medium for Coal Washeries Use of magnetite as heavy medium in coal preparation plants has been increasing steadily in recent years. It might be in short supply in some areas or excessively costly in certain times. In Turkey, the cost of heavy medium magnetite has almost tripled since 2003. As a result, alternative sources of heavy medium material have been evaluated. A maghemite ore from Elbistan-Kahramanmaras was found to be an interesting source. Tests showed that the maghemite ore can be enriched via magnetic separation at 1556 gauss to obtain a heavy medium material with 4.93 g/cm3 density and 97.22 per cent magnetic recovery. Further tests were conducted to determine the optimum field strength for magnetic separation, friability and regeneration recovery.

Sep 13, 2010

The last one decade in India had witnessed phenomenal growth in the coal, lignite, iron ore, limestone and many other minerals. To meet the production of minerals, the energy requirement is also very high both in terms of petroleum products and electrical energy. Because of spiralling prices of crude oil and also of the electrical energy, attempts have been made by various mining companies to select energy efficient mining machineries (in underground and surface) mines, together with energy efficient mining and mineral processing operations. Mineral sector of India is working seriously in tune with the Planning Commission stipulations to conserve energy.Apart from energy use (both electrical and fossil fuels) in mining, it is also significantly contributing to the cost of mineral processing depending on the quality of ore/rock being processed. Over the years a number of studies have been initiated and implemented to reduce cost of energy bill. An attempt has been made to present the various aspects of energy conservation, Impact of Energy Conservation Act 2001, Relevance of energy audit, areas of energy consumption and conservation efforts, etc in this paper. The paper also deals with some of the case studies to show how energy conservation programs has been implemented in the Indian mineral sector.

Dec 6, 2010

In a modern economy there is a compelling case why governments should not own property rights to mineral deposits. Assuming they do, however, governments will use these constitutional rights to raise revenue. They have two basic instruments to achieve this; a royalty charge on price or a rent tax on income/profits. On the one hand, a royalty charge creates a 'deadweight loss' to society by increasing cut-off grades and decreasing the life-of-mine. They are also regressive. However, they are easy to administer. On the other hand, a rent tax avoids the problem of 'deadweight loss'; it does not impact on the life-of-mine because the tax structure is neutral. But, they are difficult to administer correctly, particularly in the determination of rents and the definition of mining per se. If rents are incorrectly determined capital markets are distorted. And, if mining activities are incorrectly defined, downstream activities could be adversely affected.

Jun 1, 2010

By J B. Taylor

Geographic Information Systems (GIS) are being increasingly used by the mineral exploration industry in the search for new ore deposits. A mineral exploration GIS links geological and geophysical data by virtue of their geographic location in a digital map setting. Geological and geophysical data are categorised into a number of themes or layers within a mineral exploration GIS. These layers may include polygonal information such as rock type and tenements, line information such as faults and fold axes, point information such as mines and mineral occurences, and images such as gridded geochemistry and aeromagnetics. A mineral exploration GIS is a powerful tool to help the explorationist comprehend the spatial associations and interrelationships of his/her data. These spatial associations can be integrated with a mineral genesis model, to create a mineral prospectivity map to more effectively target exploration. Arguably a competent geologist who has a good understanding of the genesis of the local ore deposit types and knows their local geology backwards could intuitively derive a mineral prospectivity map. However, in an era of rapid data accumulation from many different disciplines, the ability to assimilate and understand is a huge task for any individual. A mineral exploration GIS enables the explorationist to spend more time analysing data and testing ideas, rather than finding and manipulating data into compatible formats.

Jan 1, 1994

By using knowledge-based technology to create a Virtual Mining Enterprise and integrating it with existing technical and financial computer systems, a gold mining company has been able to reduce the time taken to produce a mine plan from 14 weeks to less than one week. Typically, the mine planning process requires circulating and managing large amounts of information. Even with the use of computers in todayÆs business, this is often still a manual process involving file transfers and individualised spreadsheets. Mine planning also involves understanding and managing large quantities of complex and interrelated variables. Added to this is the ever changing dynamics and constraints associated with the business of mining. These issues not only hamper the planning process but also question the validity and usefulness of the mine plans being generated. By integrating the information and knowledge of the numerous departments involved in mine planning into one core Knowledge Base - so called æone version of the truthÆ, - mining companies are able to overcome these pitfalls experienced in traditional planning methods. Once set up, the Knowledge Base creates and runs a virtual mining enterprise with which to visualise and test various scenarios of mining, business and logistical activities. The final output is an optimised enterprise-wide plan with clear and detailed instructions for each of the divisions of the company.

Jan 1, 2000

By U König, N Norberg

To cope with varying raw material qualities and increasing prices for energy, a more frequent and accurate monitoring of the processing of iron ore became the focus in sinter plant operations. Traditionally, quality control in iron producing industries has relied on time-consuming wet chemistry or the analysis of the elemental composition. The mineralogy of a sinter that defines the properties and behaviour in the blast furnace is often not frequently monitored. One fast method to analyse the mineralogical composition of iron sinter, raw mixtures and iron ores is X-ray diffraction (XRD). Recently statistical methods such as similarity analysis or partial least square regression (PLSR) in combination with XRD raw data has become more and more popular in handling large amounts of data and correlating process-relevant parameters directly with an XRD measurement. PLSR can be used to correlate process parameters directly from the XRD pattern without investigating the mineral content. Hidden information that is present in the measurement but not determined with traditional methods can be used to improve the characterisation of the analysed materials.CITATION:König, U and Norberg, N, 2017. Iron sinter process control using X-ray diffraction – part : monitoring of low temperature degradation, in Proceedings Iron Ore 2017, pp 75–78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Research on the Differential Flotation of Iso-Floatable Lead-Zinc Sulfide Ore

Sep 13, 2010

By T DePetris, B B. Beamish

There has been a gradual increase in the volume of internationally traded thermal and coking coal, with emphasis on blending of coals rather than single coal usage. New Zealand can take advantage of this situation, especially with its low ash and sulphur content coals. However, there is a need to clarify the thermal and coking behaviour of these coals as they relate to other market players, to benefit both the consumer and supplier. The high volatile matter contents of New Zealand coking coals are due to their high vitrinite content, which causes them to demonstrate stronger coking properties over a wider rank range than Gondwana coals. These same high vitrinite levels appear to correspond with lower initial softening temperatures than for Gondwana coals of similar rank. Preliminary results using thermogravimetric analysis also suggest that New Zealand high volatile bituminous coals can be used to substitute for higher rank Gondwana coals in combustion processes.

Jan 1, 1994

By L A. Martinez Tipe, J McKibben, S Barry

"Metal prices are central to a mineral investment decision and have a profound impact on the financial performance of companies in the mining industry. At its most basic level, metal prices are influenced by the disequilibrium between international metal volume supply and demand. That is, the commodity price is a regulator that equates international metal supply and demand where inventories act as a buffer between the emergence of this disequilibrium and its dissolution through a price change.From this viewpoint, mining companies are required to forecast metal and bulk commodity prices when evaluating minerals projects through discounted cash flow (DCF) analysis. While supply-demand models are instructive, many companies use historical prices, spot prices, futures/forward pricing and consensus opinion (or a combination of all of these) to develop price forecasts.This paper discusses the definition, fundamentals and differences between futures/forward and consensus pricing and the appropriateness of each in a DCF model for mine project economic evaluation.Our results demonstrate that great care is required when using either futures/forward or consensus pricing and that the decision to use one rather than the other requires consideration of other important elements in the DCF model (ie the risk-adjusted discount rate).CITATION:Martinez Tipe, L A, McKibben, J and Barry, S, 2016. Metal prices and the differences between forward and consensus pricing – which one is better for use in a discounted cash flow model?, in Proceedings Project Evaluation 2016, pp 149–158 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By W Valery, S Morrell

In the mining industry blasts are usually designed to fracture the in situ rock mass and prepare it for excavation and subsequent transport. The run of mine (ROM) fragmentation is considered good when it is fine enough and loose enough to ensure efficient digging and loading operations. Mining optimisation strategy is hence usually focussed on minimising total mining costs and maintaining these ROM fragmentation characteristics. Although this approach ensures an efficient mining operation it ignores the potential impact on crushing and grinding. Investigations by several researchers have shown that designing blasts to produce ROM fragmentation to optimise crushing and grinding performance enhances the overall efficiency and profitability (Eloranta, 1995; Kojovic et al, 1995; Bulow et al, 1998; Kanchibotla et al, 1998; Scott et al, 1998; Simkus and Dance, 1998). Field experimentation in this area is often found to be difficult because of high implementation costs and insufficient understanding about the effect of fragmentation at different stages in a comminution circuit. Modelling and simulation of blasting and comminution processes provide a more economic alternative to explore the impact of blast design changes on the down stream operations (Kanchibotla et al, 1998; Kojovic et al, 1998; Adam and Siddall, 1998; Bulow et al, 1998). However, the reliability of such simulations depends on:the ability of the models to reproduce the physical processes that take place; characterisation of rock mass in terms of its blastability and comminution characteristics; and in the case of blast modelling the ability to predict fines (-10 mm) has been found to be particularly important as this fraction has a significant effect on mill throughput.

Jan 1, 1999

The profitability of gold placer mining operations is determined by more factors than many placer miners recognise until too late. This study is based upon field trips to examine the efficiency of mining and transportation of gravels to a wash plant by bulldozer and truck. At the examined open pit mining operations gravels were washed using water canons, derockers or scrubber trommels. The objective of this study was to determine the relationship between unit costs and power requirements for gravel mining and processing. The author conducted a number of time and motion studies at four open pit gold mines, including the Maly Patom Creek, the Nizhny Patom, the Taimendra Creek and the Kadali-Makit in the Bodaibo District, Irkutsk Region and collected and processed field data. As a part of the study significant correlations were determined and empiric regression equations derived between: power requirements (Ep) and unit cost (Cp) for gravel processing; and total power requirements (Et) and total unit cost (Ct) for gravel mining, transportation and processing. Based on the results of the study it was proposed to modify the current mining procedure methods and to replace water cannons at the Maly Patom Creek with a PPM-5 derocker. Introduction of the proposed technology resulted in 2004 in US$385 000 mining cost reduction at the Maly Patom Creek over a short-time Siberian mining season.

Jan 1, 2007