Search Documents

By M Scoble, E Rubio

The re-engineering of manufacturing production systems has demonstrated the benefits from using production information for optimising processes. This paper explores the techniques and issues in the acquisition and analysis of mine production data for tactical decision making in production control. The use of information and operations management tools is presented in the context of block caving studies, with particular focus on the relationship between secondary breaking and LHD production performance.

Jan 1, 2000

By V Kumar, A S. Venkatesh, R K. Upadhya

The enormous iron ore deposits of eastern India are part of the volcano-sedimentary basins containing iron and to some extent manganese deposits that belong to the Iron Ore Group (IOG) of Archaean Singhbhum Craton, occurring as western and eastern limbs of a broad synclinorium. The eastern iron basin contains typically huge amounts of blue dust and powdery ores. There is a remarkable difference between the western flank ores and the eastern flank ores and the present study is part of the eastern flank ores from Noamundi. Demand for sintered fines as blast furnace feed coupled with the higher export price for lumpy ores that produce enormous amounts of fines during processing has created a situation whereby both primary and secondary fines, such as classifier fines, are being increasingly used as sintered feed for blast furnace. Systematic mineralogical and geochemical characterisation indicates that in many cases the ROM and classifier fines have to be processed to increase their Fe content and at the same time reduce their Al, Si and P contents. The fines which are already at micron sizes are amenable for beneficiation using the Mozley mineral separator and sink float test. It was observed that beneficiation was better and significantly greater by the sink float method than the Mozley mineral separator. Mineralogical and chemical studies of the fines reveal that around 80 per cent of alumina bearing minerals (gibbsite, clay and silicates) are present in the liberated form. Microscopic studies confirmed that the iron minerals are well liberated by controlled grinding to -300 mesh sizes with the beneficiation of iron ore fines and low-grade ores carried out using the Mozley mineral separator and sink float test. Beneficiation using the Mozley mineral separator increased the grade of concentrate with increasing flow rate of water as well as increase in amplitude of oscillation of the tray, but not very significantly with the increase in slope of the tray. In this method, though, iron concentration improved from 47 to 63 per cent with a recovery of around 67 per cent. It is not suitable for industry scale operation as only a small quantity of ores can be handled at a time. Beneficiation using the sink float test produced a better result with the Fe content increasing from 47 - 49 per cent to 66 - 68 per cent with a recovery of approximately 58 per cent. Initial feed Al2O3, SiO2 and Fe contents of 9.85 per cent, 15.3 per cent and 49.8 per cent respectively were beneficiated to 2.13 per cent Al2O3, 1.5 per cent SiO2 and 67.5 per cent Fe in the concentrate, with a recovery of 54.1 per cent. In contrast, using the Mozley table resulted in beneficiable contents 66.3 per cent Fe, 3.01 per cent alumina and 2.05 per cent silica. The combined alumina and silica content for the Mozley Table was >5 per cent, which exceeds the industry requirement of

Jan 1, 2005

With the burgeoning opportunities for new gold mines to be developed the opportunity now exists for a reassessment of the optimal processing path for these gold ores. Projects have traditionally followed the path of whole ore cyanidation with either Carbon In Pulp (CIP), Carbon In Leach (CIL) or Merrill Crowe. The challenge ahead is whether these traditional processing methods are the best option for stakeholders, or to go beyond CIP and use a combination of currently available technologies that can be used to provide gold recovery at a significantly reduced capital cost and minimal deleterious impact on the environment. Either stand alone or combinations of gravity concentration and flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit. Treatment of a gravity/flotation concentrate by intensive cyanidation may be processed by the InLine Leach Reactor (ILR) developed by Gekko Systems of Australia. The advantages of the technology combining gravity/flotation followed by intensive cyanidation are significantly reduced capital costs; improved safety due to reduced cyanide inventories; the majority of tailings un-contaminated by cyanide; less energy required due to an opportunity for an increase in grind size û reducing green house gas emissions; detoxification of concentrate tailings can minimise tailings disposal and containment requirements.

Jan 1, 2004

By K Williams, T Donohue, W Chen, T Roessler, A Katterfeld

Wet sticky iron ore poses particular difficulties in every aspect of the material handling process. Material hang-ups in bins, pipes and chutes; carry-back and spillage due to insufficient belt cleaning; clogging of screens; malfunctioning of crushers as well as rat holing of gravity reclaimed stockpiles are all predominantly due to the inherent cohesion and adhesion characteristics of the wet, sticky ore (Roberts, 1993). Limited understanding and quantitative measures on the stickiness of such a material significantly lower the mining operation efficiency.This research aims to investigate the cohesion and adhesion characteristics of the wet, sticky ore on physical modelling, experimental techniques and numerical implementation. Initially, the suitable bridging mechanism that contributes to the cohesive and adhesive forces within the iron ore material was identified (Hering, Martin and Stohrer, 1989; Rumpf, 1958). A cohesion/adhesion energy density factor based contact model was then introduced to describe the stickiness of the material. Secondly, an experimental system was proposed to directly test the stickiness of the material. Such a system is able to obtain both the cohesive/adhesive shear force and tensile force of the material at a specific moisture content. Lastly, the implementation of the proposed cohesion/adhesion model into the discrete element modelling (DEM) software was also discussed. A cohesion/adhesion calibration for modelling wet sticky iron ore in DEM was then conducted to ensure the material modelled in the simulation is reflective of the reality.From the study, understanding of the cohesion/adhesion characteristics of the wet iron ore material is significantly enhanced. Experimental and numerical outcomes can be directly applied for better designing or optimising the material handling processes that involve wet sticky iron ore. Consequently, the mining operating costs can be greatly reduced.CITATION:Chen, W, Donohue, T, Williams, K, Katterfeld, A and Roessler, T, 2015. Modelling cohesion and adhesion of wet, sticky iron ores in discrete element modelling for material handling processes, in Proceedings Iron Ore 2015, pp 387–392 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By H Han, d S. Hapugoda, L Lu

With the recent rapid development of Chinese steel industry, the world iron ore resources of good quality are depleting rapidly. As a result, iron ore deposits of lower quality have been or are being developed to meet the market demand and are becoming increasingly important to iron and steel companies. As concentrates have advantages of high Fe grade and less harmful impurities, they are ideal sweeteners to maintain sinter grade and quality when high proportions of low-grade ores are used in the sinter blends. However, due to their fine nature, addition of concentrates will inevitably increase the proportion of adhering fines and reduced the proportion of nucleus particles of the sinter blends, which can adversely affect the green bed permeability and sintering productivity. In the present study, lab scale sintering tests were carried out under the conditions similar to the sintering process to examine the effect of concentrates on the high temperature sintering characteristics of sinter blends and the structure and strength of the resultant sinter analogues.

Sep 18, 2023

Gold deposits in Eastern China have characteristic of belted distribution. The concentrating belts of gold mineralization are about parallel to the island are belt in Western Pacific Ocean. Gold deposits are mainly concentrated in the aged metamorphic rock series on the upwarping zones and upwarping fault zones, and obviously controlled by the deep fractures and their deriva-tive secondary faults. Gold mineralization had genetic relation to the Mesozoic (especially Yanshan period) magmatic activity. The distribution and genesis of gold deposits can be explained by the assumption of wavy structure. The formation of wavy structure is related to the process of Pacific plate and India plate.

Jan 1, 1990

By B Davis, M Wallace, J Stewart, C F Burrett, J B. Cannell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Sepon district in Lao PDR contains 1.8 Mt of JORC (2012) compliant contained Cu resources in addition to >4.5 Moz of Carlin-like Au in a Palaeozoic sedimentary package. The Cu deposits are proximal to an EW lineament of Permian rhyodacite porphyry (RDP) intrusive centres that are characterised by intense barren quartz stockworks. The Khanong deposit (42 Mt at 3.0 per cent Cu mineral inventory) is a carbonate replacement intermediate sulfidation deposit verging on a high sulfidation environment, where abundant pyrite, copper sulfides (chalcopyrite, bornite, trace enargite), copper sulfosalts (including tennantite – tetrahedrite, colusite), and base metal sulfides (sphalerite and galena) have replaced low dipping dolomite and limestone layers, forming a manto-style orebody fed by steep dipping intensely silica-pyrite altered structures. The Thengkham deposits (54 Mt at 1.5 per cent Cu) are composed of prograde skarns (garnet, clinopyroxene) and mineralised retrograde skarns (chlorite, magnetite, hematite, epidote, sericite, talc, serpentine, carbonates, sulfides) which are irregularly and semi-continuously distributed around an elongate 4 km long intrusive centre. Thengkham and Khanong have been strongly supergene enriched, forming secondary chalcocite breccias and exotic malachite zones.The Carlin-like Au deposits display a range of stratigraphic and structural controls and lie outboard of the Cu deposits. Similar structural controls, alteration assemblages and trace mineralogies suggest that gold and copper mineralisation are temporally and genetically related. It is hypothesised that the differences in style of Cu and Au deposits across the Sepon district are related primarily to palaeodepth and proximity to the intrusive centres.CITATION:Cannell, J B, Stewart, J, Williams, P, Wallace, M, Burrett, C F and Davis, B, 2015. The Sepon copper deposits (Laos) and their relation to Carlin-like gold mineralisation, in Proceedings PACRIM 2015 Congress, pp 399–408 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By I T. Cameron

The commercial production of copper metal involves a sequence of purification stages. One step of this process eliminates bulk quantities of iron and sulphur from matte Cu2S(FeS to produce blister containing 95.5 per cent copper. This task is traditionally performed in the Pierce-Smith converter, a cylindrical vessel in widespread use throughout the copper industry. Typically, multiple Pierce-Smith converters are arranged along an aisle, simplifying material transfer from vessel to vessel. Materials are moved through the aisle in pots and boats, using overhead cranes. In terms of the overall process, the converter aisle represents a critical processing unitùit contributes significantly to the value added nature of the metal. The aisle is subject to significant process disturbances. Thus, improvements in the operationÆs modes and conditions have a direct impact on process profitability. As with any commercial operation, improvements are always sought to increase process performance. The general approach involves process modelling, followed by an application of control and optimisation theory to this model. The results of such a study are then applied to the real process, leading to improved performance.

Jan 1, 1998

By K Knorr, S Birch

The mineralogy of new certified-reference-materials (CRM) for X-ray fluorescence from Western Australia (ASCRM 030 to 035) was analysed by X-ray diffraction using the BRUKER energy dispersive one-dimensional detector LYNXEYE-XE. The samples were studied using standard-less quantitative phase analysis, based on the Rietveld method. This method delivers the relative amount of crystalline phases. All materials were found to be high-grade iron ore predominantly consisting of hematite and goethite and very low amounts of magnetite. In addition, the gangue mineralogy was characterised. It consists of low-per cent amounts of carbonate (siderite/calcite), quartz, kaolinite, chlorite and gibbsite.Furthermore, all samples were analysed with the external standard method. This is an elegant way to probe for amorphous content without adding an internal standard. All six samples were found to contain up to 16 per cent amorphous or nano-crystalline material.CITATION:Knorr, K and Birch, S, 2013. Mineralogy of new Australian x-ray fluorescence standards, in Proceedings Iron Ore 2013 , pp 269-274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By R Blin, R Walde, R Belli, D Inaudi

A fiber optic distributed sensing system allows the monitoring of parameters useful to determine the short- and long-term behaviour of the structure in response to the external actions, including, eg seismic activities as well as long-term phenomena such as seepage, tunneling, sinkholes, and other geo-structural movements. Monitoring of large retaining structures with such a system provides direct strain/deformation and temperature measurements on the broad interior area with an arrangement of several sensing cable lines, enabling early detection, localisation and sizing of subsurface damages. Measurements are provided every meter along the entire sensing cable, this is particularly important in such cases where the location of defects and damages cannot be predicted. Fiber optic distributed sensing cables are generally available for retrofit installation inside the dam structure using trenches on the downstream face or laid during construction below the geomembrane liner within the bedding sand layer. Mapping the cable route enables exact correlation between a linear coordinate on the cable length and a position in the dam. Cable installation is envisaged to be carried out during further raising of the embankment; additional cable sections are plugged to the previously installed cables and measured with the existing measurement system, requiring only an update of the mapping. The measurement system is placed remotely from the sensing area since a section of sensing cable can be used to link to the sensing area at the storage facility several kilometers away. The system is available for on-line, 24/7 real-time operational data management. Such fiber optic distributed sensing systems allow storage facilities to be monitored with long, accurate, continuous and precise data for geotechnical diagnostic purposes. This contribution will introduce the principles, benefits, and limitations of this technology.

Jul 1, 2021

The considerations which led to the decision to_ install discs at the Dampier Pellet Plant of Hamer ley Iron Pty. Ltd. are described. Initial testwork showed that the ore could be ground dry in open circuit to a Blaine index of 2500 cm2/g and that it pelletized readily. The various design criteria including diameter, slope, speed, motor size, depth of sidewall, feed point and water spray location were then determined. Plant performance after commissioning is described including the various problems encountered and the modifications since carried out to overcome them. The main problem was quickly identified as disc feed rate control. Various bin and bin feeder modifications were tried to overcome the effects of the fluidising characteristics of the dry ground ore. Other factors found to affect disc operation are ore size distribution, additives and operator competence.

Jan 1, 1974

By A Nigam, K Biswas, R Sarkar

Because of the problems with 1st and 2nd generations of Advanced High-Strength Steels (AHSS), a 3rd generation of AHSS steels has become prominent and these steels have properties in between the 1st and 2nd generations of AHSS. However, although the 3rd generation of AHSS is a promising candidate as a replacement for its predecessors, there remain some challenges in processing these steels which are essentially medium Mn (Mn content ~ 5–7 wt per cent) and high Al (Al content ~ 1– 3 wt per cent) steels. The use of conventional casting powders based on the CaO-SiO2 system is unsuitable for high and medium Mn/Al steels. This work investigates the development of CaO-Al2O3- based mold fluxes for casting third-generation AHSS steel. Mold fluxes, with otherwise similar compositions but different C/A ratios, are tested and their crystallisation behaviour is examined using differential scanning calorimetry (DSC). A calcium aluminate phase having a composition Ca12Al14O33 was found to be the main crystalline phase in the mold fluxes. A decrease in crystallisation temperature was observed as the CaO/Al2O3 ratio increased from 1.00 to 1.33. The effective crystallisation rate constant exhibited an increase with decreasing crystallisation temperature, indicating a potential influence of nucleation rate on the overall crystallisation rate and suggesting an anti-Arrhenius behaviour in the crystallisation process of these mold fluxes.

Aug 21, 2024

By A C. Robertson

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

Jan 1, 1998

Hydraulic backfill is generally retained in slopes using permeable barricades. Mitchell et a! (1975), Mitchell (1992) and Grice (1989) have shown that under normal drainage conditions, barricades experience low levels of loading. Cowling et a! (1988) have also shown that barricades are susceptible to piping failures if excess water has ponded on the upper backfill surface and if leakage of backfill from the barricades has occurred. During 1997, six hydraulic backfill barricades failed in four different Australian mines. Fortunately, in each case, the quantity of backfill slurry released was small, and no injuries to personnel nor damage occurred. Detailed investigation of two of the incidents showed that the primary cause of failure could be attributed to the delivery of excess quantities of transport water from the low-density slurry. For each of the incidents investigated there was evidence of the development of piping failures, which resulted in hydrostatic loading conditions on the barricades from the ponded water on the upper backfill surface. The circular failure surfaces in the barricades were characteristic of the application of point loading Conditions.

Jan 1, 1998

By R S. Sing, M D. Yadav, G Udaybhanu

This paper presents the results of the first part of a research project to study the effect of various inhibitors to reduce the spontaneous heating susceptibility of some highly susceptible Indian coal seams. In this investigation 11 inhibitors were chosen and applied at three, five and ten per cent of their concentrations in an aqueous solution for four coal samples collected from four different seams. The susceptibility of coal samples, before and after application of these inhibitors, was determined by carrying out crossing point temperature (CPT) analysis. The findings of this study have indicated that it is possible to retard the tendency of spontaneous heating of Indian coals to a considerable extent by the application of six of the inhibitors studied. Further, these inhibitors were tested in 1:1 combination to study their synergistic effect. Finally the economics of the application of these inhibitors has been analysed and four inhibitors are recommended for field use. These results have direct application to control fire and improve productivity and safety in coal mines.

Jan 1, 2005

By A G. L Pratt, M S. Kemp

BHP has used many innovative techniques when recruiting its workforce for the Cannington Project. Looking for a balance of experience and enthusiasm it was necessary to develop pre-selection tests to reduce the initial number of applicants to a manageable number for first interviews in Townsville. Success at this stage led to an applicant, and their spouse, to go through a second interview at the mine site. The full process from application to job offer took up to six months, but the results were felt to be worth the effort. The approach taken has resulted in a highly motivated and flexible workforce. This paper outlines the philosophies behind CanningtonÆs recruitment process, highlights some of the issues associated with the approach, and offers some measures of the outcomes.

Jan 1, 1998

By L Neems

In conjunction with Orica Explosives, Worsley Alumina have managed a program of continuous improvement to their cap rock blasting over the last two years. Blasting conditions are challenging because of the hard and shallow nature of the material. Blasting costs must be controlled and the environmental consideration of noise and dust is critical. Worsley have sought to determine the optimum balance between drilling and blasting costs and fragmentation. As the cap rock has few inherent weaknesses, loader productivity is strongly controlled by the degree of fragmentation from blasting. The optimum blasting solution is also constrained by maintaining airblast levels at the surrounding residences below 115 dBL . The major blast design parameters optimised during the program were stemming type, stemming length, powder factor and blasthole diameter. A series of carefully managed trial blasts were fired during 1997 and 1998 to quantify the effect of these parameters. Fragmentation was digitally measured using OricaÆs Powerseive G technique. Shovel productivity, airblast levels and blasting costs were also quantified. As a result of the project, Worsley now have an increased knowledge of the key parameters driving blast performance, and their consequent impact on downstream processes, the environment and total mining cost.

Jan 1, 1999

By J Bang, I-H Jung

Ti is an important constituent for steels and superalloys. During the continuous casting process and ElectroSlag Remelting process (ESR), Ti in molten steel and superalloy can have chemical reactions with casting flux and ESR slag containing CaO and CaF2. In order to investigate such exchange reactions, the understanding of the (Ca,Ti//O,F) reciprocal slag system is prerequisite. In the present study, a coupled phase diagram experiment and thermodynamic modelling of the (Ca,Ti//O,F) reciprocal system was performed. In particular, the phase diagram of the CaF2-TiO2 system was experimentally investigated by Differential Thermal Analysis (DTA) experiment and quenching experiments followed by Electron Probe MicroAnalysis (EPMA) phase analysis. The Gibbs energy functions of all solid and liquid phases in the (Ca,Ti//O,F) reciprocal system were optimised to reproduce the present data and all available reliable experimental data in literature.

Jun 19, 2024

The Sishen iron-ore-mine produces 3 pro= ducts with size gradings of 25 to 8 mm, 11 to 5 mm and 5 to 0,2 mm and has a product capacity of 20 Mtpa. Ore is produced at an average Fe content of 66,2 % Fe for the two coarser pro= ducts and an average of 65,3 % Fe for the fine ore product. Three stage crushing is practised to re= duce the run-of-mine ore to -90 mm after which it is screened into five different size frac= tions of which four are heavy media beneficiated in static baths and cyclones and the fifth frac= tion discarded to slimes dams. A final three stage crushing and screening process is employed to produce the final three Products which are homogenized by means of blen=ding systems nrinr to despatch.

Jan 1, 1987

By G Bournival, Y Pan, S Ata

A custom-made set-up that measures bubble coalescence time and the thin film balance (TFB) technique were used to explore the role of residual xanthate (potassium amyl xanthate, PAX) and salt (NaCl) on the adsorption of two frothers (methyl isobutyl carbinol-MIBC, and di-propylene glycolDPG) at the air-water interface. This paper is primarily focused on the comparison of these two techniques in studying the interaction between the flotation reagents and salt emphasizing their capabilities and limits. The results from the coalescence rig showed that the presence of PAX improved the stability of bubbles in both frother solutions and led to a bubble coalescence inhibition at 50–500 ppm DPG. These measures were compared with the results from the TFB. Findings from the TFB were overall in good agreement with the bubble coalescence time, but a higher stability level was observed in thin films under the same condition. The effect of salt on the frother and PAX mixture was also explored, and the results showed an adverse impact of the salt on the interaction of frother and PAX with both techniques. However, variations were found between them in some cases. The TFB is much more sensitive to the presence of dissolved gas and oil droplets.

Aug 24, 2022