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By A K. Bhatnagar, S Saha, P Dixit, A K. Mukherjee, P Patra

TATA Steel’s R&D Division at Jamshedpur has developed a slime beneficiation process to recover iron values from iron ore slime. This process recovers iron ore concentrate containing 2.2 per cent alumina from a feed containing 7–10 per cent alumina. The reject generated from beneficiation of iron ore slime is treated as waste as the iron content in the reject is below 45 per cent. Effective utilisation of this waste is required for making the iron ore slime beneficiation process a zero-waste technology. In this connection several studies were made towards utilisation of slime waste. One of these studies revealed that slime waste can be used as a soil conditioner. Slime waste contains particles of size less than 10 micron and when these particles are mixed with soil in definite proportions, the porosity and the permeability of the mixture goes down. As a result, the water holding capacity (WHC) improves. This concept was evaluated through a series of tests at greenhouse level to optimise the soil to slime ratio. Finally, a pilot scale field trial was carried out over a period of three months using paddy rice as the crop. Three separate plots with compositions of: soil + organic matter comprising Farmyard Manure (FYM), (ii) soil and slime waste (2:1) + organic matter (FYM), and (iii) soil and slime waste (2:1) + organic matter (FYM) + Nitrogen, Phosphorus and Potassium (NPK) fertiliser were used for the pilot trial. The results showed a 20 per cent increase in the productivity of paddy rice for plot (ii) as compared to plot (i). This was due to the beneficial effect of slime waste in the soil. The addition of inorganic fertiliser such as NPK in the ratio of (4:2:1) further enhanced the productivity of paddy rice.

Sep 18, 2023

The sulphide ore occurring in the North Mine at Broken Hill is of a complex nature, consisting of an intimate mixture of argentiferous galena, marmatite (zinc-iron sulphide), and gangue minerals. A typical analysis of the ore is:Lead 15.2%Zinc 12.0%Iron 5.3%Manganese 0.8%Copper 0.1%Alumina 0.3%Lime 0.9%Sulphur 11.1%Insoluble 53.8%Carbon dioxide 0.3%Undetermined 0.2%Silver 9 oz. per tonTotal 100.0%The metallurgical practice for the recovery of the lead concentrate and zinc concentrate from the crude ore is briefly described in the following pages.(1) COARSE CRUSHING AND FINE GRINDING OF THE CRUDE OREThe crude ore from the mine, containing lumps to the size of, roughly, 10 in. x 8 in., is tipped over grizzlies with the bars spaced 3 in. apart; the oversize gravitating to a...

Jan 1, 1933

By M Camarda, A Pirson, F Vasconcelos, J Mesquita

ArcelorMittal Prijedor is a goethitic iron ore mine located in the north-west of Bosnia and Herzegovina, which mainly supplies ArcelorMittal’s European subsidiaries. Annual production of the asset stands at the level of 1.5–2.1 million tons of iron ore product which is sent to ArcelorMittal Zenica steelmaking plant. Two types of products with approximately 50 per cent Fe are generated in Prijedor through a process composed by crushing, screening, and magnetic separation stages. Within this process one of the tailings produced is called ‘ultrafines’. The ‘ultrafines’ product corresponds to the desliming hydrocyclones overflow in Prijedor plant, which is classified in a size fraction below 25 μm and corresponds to about 5 per cent of feed. This material is richer in iron than the coarser size fractions of the ore but do not present a good performance in concentration processes. In this way, several studies have been carried out during the last years to find solutions to use the ‘ultrafines’ material without success. In this context, the possibility of dehydroxylate the goethite contained in the material transforming the mineral into hematite and thus increasing the iron grade of the final product was investigated. During the research, several dehydroxylation tests with different temperatures and time of exposure were performed. Using dihydroxylation process at temperatures higher than 800°C it was possible to produce a material with 43 per cent Fe from the original 39 per cent Fe ‘ultrafines’ sample. In addition, the dehydroxylation tests confirmed that goethite becomes completely transformed into hematite at 400°C (with an exposure time of 60 mins) and material is completely sintered at 1200°C. A simulation study based on dehydroxylation tests results showed that it would be possible to use a ‘ultrafines’ product with Fe grade higher than 45 per cent to produce a material with 50 per cent Fe through a complete dehydroxylation process.

Sep 18, 2023

By J L. Stacey

The diverse priorities, drivers and concerns of multiple stakeholders in the minerals industry complicate the integration of sustainable development considerations into mine design, as well as operational and strategic decisions. The ability of the industry to address all role-playersÆ needs, or indeed, to achieve consensus among all role players on the plethora of sustainable development issues seems a noble yet unattainable goal. One of the difficulties in assessing the relative importance of sustainable development issues across many stakeholders is the inevitable lack of impartiality in valuing these issues. Starting from a premise that transparency and fairness of the process are absolute prerequisites for progress, but that consensus is not, an approach has been developed in which all stakeholders are asked to assess the importance of all other stakeholdersÆ priorities, excluding their own. The approach recognises that stakeholders have different levels of contribution, understanding, vested interests, and perceptions of legitimacy and entitlement, across the diversity of sustainable development issues and decision criteria. Using Triangular Value Analysis, the relative weightings of each of the stakeholderÆs priorities are determined through a regression-like technique. The uniqueness of this approach is the manner in which self-assessment bias and overemphasis of stakeholdersÆ own priorities are avoided. The methodology can be used for both internal and external stakeholders, and in conjunction with other group decision making techniques, such as the nominal group or Delphi techniques. This paper will illustrate how Triangular Value Analysis may be applied in the minerals industry to determine priorities in various decisions relating to potentially conflicting sustainable development priorities within the industry.

Jan 1, 2009

By U König

The use of high speed detectors made X-ray diffraction (XRD) an important tool for quality and process control in the mining industries. Besides knowledge about the mineralogy of a sample it provides useful information in terms of quantification of the crystalline phases and the amorphous content. Cluster analysis of XRD data can facilitate multi-dimensional mapping of ore deposits and drill cores, identifying regions of favourable mineral compositions. The studies of this paper demonstrate how XRD and data clustering can be used for grade control, process optimisation and quality control of iron ores and iron ore sinters. These new developments have an enormous potential as an inexpensive, reliable tool, useful in the characterisation of iron and sinter materials implemented in an industrial environment.

Jul 11, 2011

By M G. Aylmore, L W. de Klerk

Roasting of refractory gold ores has been a commercial process for many years. Improvements in design of fluidised bed roasting technologies and low capital and operating costs compared with other refractory treatment processes can potentially make roasting a viable option.However, gold extraction from roasted ores carried out on laboratory scale equipment often invariably yields lower recoveries than other processes such as bio-oxidation or pressure oxidation. Non-optimal laboratory roasting conditions can incorrectly write roasting off as a process option.Low gold recoveries from the cyanidation of calcine products from roasting can often be attributed to roasting conditions not favouring gold liberation and agglomeration processes, particularly if lockups of elements such as arsenic are being pursued for environmental reasons.This paper reviews the conditions favoured for gold agglomeration and accessibility of gold to cyanide, test conditions to achieve gold liberation and agglomeration on laboratory scale and designs that incorporate staged decomposition and roasting to make roasting a more commercial option.CITATION:Aylmore, M G and de Klerk, L W, 2013. Conditions and design considerations for maximising recoverable gold in roasting of refractory gold ores, in Proceedings World Gold 2013 , pp 375-388 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By J Battista, J Grace, I Brunton

The need to better understand and develop strategies to improve instantaneous shovel productivity at the Cadia Hill Open Pit Mine (CHM) instigated the development of the æShot to ShovelÆ project. This project has involved the implementation of a drill and blast (D&B) information management system to capture current and future experience. Equally important has been the manual monitoring of shovel productivity and direct use and analysis of high precision GPS and productivity data logged by ModularÆs Dispatch System. The analysis of this type of data was facilitated with the application of GIS based software (ie MapInfo). This has shown to be a powerful medium to display, interpret and assess this type of spatial information on a blast-by-blast basis. Cadia HillÆs well-defined D&B processes supplemented with the application of the above systems are providing a unique capability to assess and better understand the impact of both muckpile conditions and operator proficiency on instantaneous loading productivity. This is facilitating the definition of appropriate optimisation strategies in both drilling and blasting and operator proficiency training. This paper gives a summary of the work conducted in the æShot to ShovelÆ project, describes the engineering tools being implemented and discusses preliminary findings and their practical implications.

Jan 1, 2004

By Jones S. C

The problem of sealing a fluid serieite zone at a hole depth of 4000 ft was overcome by using a composite non-return valve plug and rod assembly which enabled cement to be forced under pressure into the zoneà

Jan 1, 1966

By S R. Pecover

AustraliaÆs opal and sapphire mining industry has fallen from its peak in the 1980s and 1990s into a significant low today. This is not due to exhaustion of the resource, but instead an over-reliance of the Australian miner on achieving a fair price for the gemstone product from offshore middlemen dealers. Gemstone and geological research is also at a low as Federal higher education expenditure has fallen with research institutions relying increasingly on private funding in an environment of restricted autonomy and flexibility for researchers. What little remaining research skills the universities have is being bled into the private sector as a result of the mining boom and encouraged by lower than average academic salaries. Nevertheless, some highly innovative research has been taking place, often by self-funded individuals and retired academics simply with a desire to advance the understanding of the particular branch of science in which they are interested. New models for the formation of sapphire and opal are now beginning to be applied to the exploration for these gemstone commodities. This research, together with well thought out plans for managing the gemstone product through its value-adding steps to the jewellery retail level, has the potential to bring about a resurgence in the Australian gemstone industry.

Jan 1, 2008

By S Lal, S Rost, Q Williams, K Collerson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Shoshonite suite (absarokite-shoshonite-banakite) and adakite-hosted epithermal Au deposits are a feature of circum-Pacific magmatism. Fijian examples include Tavua (Emperor) and Tuvatu on Viti Levu. New discoveries of shoshonite suite and adakite-hosted epithermal Au mineralisation have been made in the southern Yasawa Islands and in central-northern and central-western Viti Levu. The Fijian shoshonites define four NE–SW trending suites. The oldest is the northern 7.9–5.0 Ma Yasawa suite, followed by the 4.7–3.5 Ma Sabeto–Tavua–Rakiraki suite in northern Viti Levu, the 4.7–4.2 Ma Yanuca–Vatulele suite approximately 20 km south of Viti Levu and the 3.4 Ma Astrolabe suite approximately 75 km further south. Shoshonite suite lithologies with 3.8–3.0 Ma ages also occur in the Lomaiviti islands between Vatu-Cake and Moala, to the east of Viti Levu, defining a trend oblique to the NE–SW shoshonite belts. Seatura, a 3.3–2.8 Ma ocean island basalt (OIB) volcano, sits at the northern end of the Lomaiviti trend shoshonites. Trace element/isotopic chemistries indicate that shoshonite arc magma genesis involved the melting of a hydrated supra-subduction zone mantle wedge and also a lower mantle-derived plume (OIB) component. The upwelling plume provided heat for melting and possibly Au enrichment. Accessing the melt generation zone associated with the plume required a slab conduit or window. Such slab windows form by tearing during subduction or occur at slab edges. Adakites form by plume-induced slab melting. The four NE–SW Fijian shoshonite suites are interpreted to occur in back-arc extensional zones above a slab window (tear) that migrated southward during rollback of the New Hebrides–Vanuatu subduction zone. The plume (Seatura OIB) that is interpreted to have caused mantle wedge melting and formation of the Lomaviti trend shoshonites was focused along the interface between the north-dipping Vanuatu–New Hebrides subduction zone and the west-dipping Tonga subduction zone, which we have seismically imaged at approximately 400 km depth. Our model ‘cracks the metallogenetic code’ for shoshonites and adakites and has regional and global implications for Au exploration.CITATION:Collerson, K, Lal, S, Williams, Q and Rost, S, 2015. Cracking the metallogenetic code for Fijian epithermal gold mineralisation , in Proceedings PACRIM 2015 Congress, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Siwiec A

The laboratory investigations which are necessary to evaluate the mineral processing effectiveness usually include density separation of narrow size fraction of the feed and one of the products. In each size - density fractions the content of valuable mineral has to be determined. These data and yield in each size - density fraction can be specified by a matrix of partition coefficients. They are counterparts of recoveries. These coefficients can be compared with the mean recoveries at each density or size fraction or the total recovery, to determine which density - size fractions are processed in the best or worst way. The basic categories are: vector of metal content l _i 1711, 7t2, òòò, ltM I ò vector of particle size distribution x = I d1, d2, ..., dN I ò matrix of partition coefficients P11, P12, Pi N P _ P21, P22, ..., P2 N PM1 PM2..., PMN These three conceptions allow one to determine all the basic metallurgical parameters of a mineral processing unit. Losses of valuable mineral are connected with: ò mineralogical composition of the ore (types of minerals, their properties, dissemination, crystallochemical affinity, type and properties of gangue minerals), ò applied technology and technical equipment (beneficiation as a stochastic process, processing methods, process control, intergrowth liberation, water quality). Examples of application of the analytical method proposed are given for zinc - lead and coal processing plants.

Jan 1, 1993

In North-West Nelson the Riwaka Complex, a linear basic intrusive complex, is exposed for approximately 45 km. Some 500 km south, across the Alpine Fault, a linear zone of similar but less well known basic intrusives that may be correlatives of the Riwaka Complex is exposed discontinuously for about 80 km. The Complex was emplaced at several centres along a major tensional fracture zone that developed in upper Carboniferous to Lower Permian time. This fracture zone probably formed in response to the development of a west dipping subduction zone that gave rise to the Permian volcanic arcs in east Nelson and western Southland. The Riwaka Complex contains three rock suites. The Fractionation Suite, characterized by cyclic mineral layering and small scale cumulus banding is the largest and is divided into the Ultramafic, Hornblende and Plagioclase Series, each of which is subdivided into several units. The Cumulus Gabbros represent a restricted but important suite of unusual composition, while the third suite is the late phase Diorite Suite. Except in the lower units of the Ultramafic Series sulfide mineralisation is widespread. Pyrrhotite is the dominant sulfide with lesser chalcopyrite pentlandite and pyrite. Four significant zones of sulfide accumulation are recognised and discussed in some detail. Evidence suggests that the primary magma from which the Riwaka Complex was derived was sulfur deficient. It is concluded that the sulfur content of the Riwaka Complex was derived from assimilation of sulfur rich wall rocks during intrusive processes.

Jan 1, 1980

A good deal of experimental work has been done from time to time on the application of compressed air to the elevation of wet pulp. On account of the flat nature of most of our mill sites elevation of the pulp has to be provided for, and the various methods in vogue show considerable loss of time, in the replaceing of wearing parts. During the last two years the writer has carried out a great many experiments with a view of devising an elevator that will give continuous work with a minimum of wear.The results do not show a high efficiency for the power employed, but the lift is continuous in operation, very cheaply installed, and possesses no wearing parts. The lift was tried working in a bore hole of 8 in. diameter, but in many cases it is more convenient to sink a small well for the purpose. The result to date showed that the most efficiency was obtained when the depth of the wellwas not less than the height of the lift required. The pressure of air required in pounds per square inch was (approximately) half the number of feet to be lifted.In the majority of cases the lift required varied between 20 ft. and 50 ft. and the air pressure required between 10 lbs. and 25 lhs. per square inch. In most existing installations the air compressors in use were delivering air to the receivers at about four times that pressure, and when air so compressed was expanded to perform its work at a reduced pressure, it was apparent that the power exerted in origInally compressing the air above the working pressure required at the lift was absolutely lost.

Jan 1, 1901

By G Harbort, D Clarke, D Morgan, C Sola

Northparkes Mines commenced production in 1994 and the mine has significant reserves to allow operation into the future. There are a number of potential future concentrator feed sources with variable sulfide mineralogy and grades.In February 2012 a comprehensive flotation survey was conducted to allow mass balancing and evaluate the operation of the flotation circuit. A rudimentary, copper element only, unsized flotation simulator was developed to evaluate high level potential for optimisation and improvement. In 2013 this flotation model was expanded to produce a mineral based, floatability component model to estimate the effect of future concentrator feed source on metallurgical performance. This revised model allows various circuit configurations to be simulated to provide a high level blueprint for the long-term planning to maximise performance.This paper provides a review of the process followed to develop the model, including an analysis into the mineral floatability component model and its calibration against plant operations. The effect of varying feed mineralogy and feed quality on future performance has allowed an internal review of potential circuit changes needed to accommodate the changing future feed.CITATION:Clarke, D, Harbort, G, Morgan, D and Sola, C, 2014. Northparkes Mines – flotation and planning for the future, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 203–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By L Manca, P B. Hills, D Tyler, N Pollington

This paper describes a collaborative project undertaken by Newcrest Mining Limited (Newcrest) and pitt&sherry to identify, develop and then implement global best practices to manage the exposure to inrush (dry and mud) hazards in underground mining operations. An extensive literature review was undertaken to identify past experience globally and the current state of knowledge and practice in managing inrush hazard. A key requirement of the literature review was the development of a list of guiding questions which would form a framework for approaching operators to discuss the topic, capture recent learnings and understand current operating practices to allow the development of a best practice solution. An initial cohort of 14 mines across four continents chose to contribute and detailed interviews were carried out by the project team. The outcome from the literature review, interviews with participating mines and various internal discussions was a comprehensive summary document detailing Basic versus Best Practice management of the inrush hazard. This document is being used as a gap analysis tool by Newcrest to assess and guide the management of inrush hazard at their existing and future operations. The summary document has also been provided to the participating mines for their consideration. The project is iterative and will continue to evolve as new experiences, knowledge and practices come to light.

Mar 15, 2021

By G D. Price

The Golden Blocks Goldfield is located in the Slaty Creek area,North West Nelson, about 20 km west of Collingwood. Alluvial gold was discovered in Slaty Creek in 1861. Gold was mined from quartz veins up to 1.5 m thick at nine mines from the 1890s until the closure of the Aorangi Mine in 1911. Total production from the Golden Blocks Goldfield is estimated at 46 000 ounces of gold. The Aorangi Mine was the largest mine, with a recorded production of 27 978 ounces of gold at an average grade of 36 g/t. Quartz veins containing gold and sparse sulphide mineralisation occur in a slightly metamorphosed, complexly deformed over-turned sequence of Lower Ordovician sandstones and shales. Primary gold mineralisation is associated with intensely deformed zones that occur near or at carbonaceous shale and sandstone contacts. Some eighty-five percent of all gold production (39 000 ounces) came from four mines confined to the stratigraphically lowest, most widespread shale unit. The quartz veins exhibit textures consistent with a hydraulic fracturing mode of vein formation with fissure infill vein types predominating over replacement textures. Stylolites of carbonaceous material and recrystallization features within the veins suggest multiple phases of deformation. The lack of wall rock alteration, and low primary fluid inclusion temperatures of 200¦ - 265¦ indicate that the ore fluids were associated with a low temperature epithermal system. A model consistent with similar mineralisation styles observed in Ordovician sediments from Pacific Rim occurrences is presented. The high grades (up to 100 g/t) mined from the upper levels of several mines suggests supergene enrichment processes associated with the Upper Cretaceous weathering surface. The Golden Blocks Goldfield has had no modern exploration. The most recent exploration was undertaken in the early 1980s. There are known acid intrusives in the area, with potential for the application of new models of intrusive-related gold mineralisation.

Jan 1, 2004

By N Guresin, R Dunne, S Blanco

This paper presents the results of research work conducted to assess if aqueous solutions of sulfur dioxide (SO2) can be used to treat roaster calcine leach residues such that recovery of gold in this material can be achieved with subsequent application of the thiocyanate (SCN-) leaching system. The project is mainly aimed at assessing an alternative use for sulfur dioxide gas generated during flotation concentrate roasting. The calcine leach residue sample used in the study contained 2.56 g/t gold. The reason for this high level of residual gold is thought to be due to gold surface passivation by thin iron oxide films, presence of gold in solid solution with refractory iron oxides and encapsulation of gold in the structure of these iron oxides.The study was conducted in three stages. The first stage was the characterisation of a sample from a roaster calcine leach residue. The second stage in the project was a set of leaching tests to assess the feasibility of using aqueous solutions of sulfur dioxide to reductively dissolve refractory iron oxide mineral phases contained in the calcine. The final objective was to assess the efficiency of thiocyanate, a gold complexing ligand stable under acidic and oxidative conditions, to extract gold liberated during sulfur dioxide leaching.The study showed that the reductive sulfur dioxide treatment of the calcine leach residues followed by oxidative thiocyanate leaching to extract gold was not a particularly efficient process as only around 20 per cent gold could be extracted. Leaching the calcine residues by any of these systems separately also extracted the same amount of gold (12 - 14 per cent) implying that irrespective of the solution potential, the acidity helps dissolution of gold encapsulating minerals, mostly hematite, but at a very slow rate. The findings on the topic in the literature and during this study show the requirement for further technical investigations and economical analyses on two cases. The first case is to roast gold concentrates to produce magnetite rather than hematite followed by sulfur dioxide and thiocyanate leaching of magnetite containing calcines. The second case is to apply a magnetic concentration process to conventional roast-cyanidation calcine residues to produce a gold-rich magnetite concentrate that can be further treated with sulfur dioxide followed by thiocyanate leaching.For both cases, the best evaluation of the sulfur dioxide leach system in extracting residual gold from calcine leach residues will require a detailed economic analysis to find out the balance between the value of the gold recovered and the loss of revenue from acid production. There are a number of roasters that do not produce acid. In these cases, a portion of the unwanted sulfur dioxide gas can be used to recover gold in magnetite containing calcines as an economic incentive.CITATION:Guresin, N, Blanco, S and Dunne, R, 2013. Leaching roaster calcine leach residues with aqueous solutions of sulfur dioxide and thiocyanate, in Proceedings World Gold 2013 , pp 129-136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By L Jackson, A Parbhakar-Fox, N Fox

"Characterisation of sulfide minerals (eg pyrite, sphalerite) in historic tailings can assist in determining whether there are economic benefits of reprocessing such materials using modern metallurgical practices. In addition, there are associated environmental advantages if the historic tailings are actively generating acid and metalliferous drainage (AMD). At the Old Tailings Dam (OTD), Savage River, Western Tasmania, 38 Mt of pyritic tailings were deposited from 1967 to 1982; consequently it has been recognised as an AMD source. Long-term management options considered for this site have included the establishment of either a water, hard-engineered or vegetation cover. However, due to geotechnical challenges posed and the lack of success demonstrated by previous pilot studies, these strategies have not been implemented. Instead, resolving the pyrite chemistry can allow for a first-pass assessment of whether reprocessing these tailings is a feasible option as part of a long-term management strategy for this legacy site.Tailings samples (n = 144) were collected across the OTD from up to 2 m depth from five facies (A–E), and four zones (1 to 4; defined by hydrological regime and grain size). These materials were subjected to acid-base accounting (ABA) and mineralogical evaluations to determine their geoenvironmental characteristics. Following this, 26 samples were selected for in-depth laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) investigations to evaluate pyrite chemistry across different tailings facies. The results revealed enrichment of Co and Ni in these materials. Specifically, Co content was up to 3.0 wt per cent, particularly within facies C to E, and Zones 3 and 4. Cobalt is recognised as a critical metal, therefore, reprocessing should be considered as a future rehabilitation option for the OTD, pending resource definition using established codes and practices.CITATION:Parbhakar-Fox, A, Fox, N and Jackson, L, 2016. Geometallurgical Evaluations of Mine Waste – an Example from the Old Tailings Dam, Savage River, Tasmania, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 193–204 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By A Giyose, V Malysiak, K Davey

Batch flotation tests were conducted on a haematite-bearing Sishen iron ore slimes sample from South Africa using reverse cationic flotation. The effect of grinding on flotation performance, the flotation response of various key impurities in the sample, and the feasibility of increasing metal recovery by refloating tailings in a scavenger flotation step were investigated. The test results indicate that reverse cationic flotation is effective in rejecting impurities from the iron ore sample tested. From a head grade assaying 6.4 per cent SiO2, 2.14 per cent Al2O3, 0.402 per cent K2O, 0.082 per cent P and 0.194 per cent TiO2, the levels of impurities were reduced to 1.83 per cent SiO2, 0.88 per cent Al2O3, 0.095 per cent K2O, 0.066 per cent P and 0.174 per cent TiO2 in the final concentrate at a Fe recovery of 74 per cent. The flotation response of SiO2, Al2O3 and K2O were found to be better than that of P and TiO2. The testwork demonstrated that grinding to 80 per cent passing about 49 microns is essential for upgrading the Sishen iron ore to produce >67 per cent Fe concentrate grade. This grind size corresponds to about 80 per cent liberation of haematite from the gangue minerals. Fe recoveries up to 76 per cent were obtained by refloating the rougher tailings in a scavenger stage, with little effect on the final concentrate grade. Size-by-size Fe recovery data obtained indicated that particles below ten microns were mostly lost in the desliming stage conducted prior to flotation whilst some reported to the froth by entrainment. Some of the coarser haematite-gangue composite particles reported to the froth product by genuine flotation.

Jan 1, 2009

By R Moreby, J Kok, L van den Berg

The high production rates achieved from mass mining methods such as block caving, sublevel caving and longwall mining require large conveyor belts, trucking loops (diesel/electrical) and rail systems for ore handling. However, the ore handling systems used in mass mines introduce a significant amount of heat into the overall ventilation system, which may be problematic at depth or in mines located in hot climates.In particular, the heat load from a conveyor system is not always well understood and consists of various components, including frictional heat from idlers, heat from electrical motors, heat from the drive train and heat from broken rock transported on the conveyor system. This paper presents results from a study that investigated the heat introduced to the ventilation air from a large conveyor system. The conveyor system transports ore with a maximum virgin rock temperature of 41°C from a depth of over 1 km. Air, belt and rock temperatures were measured in the conveyor system to evaluate the distribution of heat loads.CITATION:van den Berg, L, Moreby, R and Kok, J, 2015. Heat load estimation from conveyor systems in mass mines, in Proceedings The Australian Mine Ventilation Conference, pp 63–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015