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By S Zummar, A Van den Bulck, T De Staercke, T Van Rompaey

An increase of 22 per cent in lead usage is expected in the European Union by 2050. During lead refining, the Harris process is a critical step in which a salt melt is used to remove arsenic, tin and antimony. During this process, the caustic salt melt absorbs these impurities, requiring regular evacuation before saturation. Current metallurgical practices for: 1) determining the end point of the lead alloy involve time-consuming sampling and offline analysis, and 2) determining the end point of the caustic salt melt are based on subjective visual observations by the operator. In the context of Industry 4.0 concept, automating these processes becomes desirable, as smart sensors systematically collect real-time data in an unbiased manner. This research focuses on monitoring the Harris refining process using objective methodologies. Two different methodologies are investigated. The first methodology focuses on electrical conductivity changes of the caustic salt melt as function of Sb content. For this study, synthetic and industrial samples are used. A lab-scale electrical conductivity set-up was built to accommodate the aggressiveness of the salt melt. Initial findings suggest a promising relationship between electrical conductivity and Sb content in the caustic salt melt. Although the results are preliminary, the study provides valuable insights by enabling real-time measurements. The second methodology focuses on measuring the electromotive force (EMF) in lead doped with Sb at pilot-scale. Multiple probes are reevaluated for their effectiveness in Sb measurement. Ultimately, a partially stabilised MgO probe with Ni as a reference, without cardboard and copper protection caps, yields promising results. A correlation between EMF and Sb content is observed. However, repeatability issues arise due to possible wire interference at low temperatures. The results underscore the potential of advanced measurement techniques in optimising lead alloy production within the context of Industry 4.0.

Aug 21, 2024

By V Yadi

Geostatistics has been widely used for more than four decades as a powerful tool in ore resource/reserve estimates and grade control. This method has gradually replaced the conventional method such as polygon and cross-section for grade estimation by more mathematical techniques such as kriging. The advances in geostatistical understanding and the availability of appropriate software packages have given much more contribution in speed and high accuracy during production. However, in many cases, these techniques are sometime applied without support with a good thorough understanding of the geological controls on metal distribution. To produce the result close to actual, the geological control in interpretation and appropriate geostatistical task is a must. Geological logging was described in the core must be consistent with the level plan produced by commercial modelling software used as a guide for grade control during production. Experience gained through evaluation of the Central I deposit resulted that the most effective systems continue to be based on geostatistical methods of resource estimation. Computer applications modelling software packages are necessarily as the core of an efficient in undertaking these assignments. They contribute to make a valued to data management and are becoming increasingly effective during processing. The latter role is particularly important to check the actual versus estimated values where will significantly to improve personnel to have a confident with their knowledge combined with experience and complete their jobs satisfy.

Aug 22, 2011

By P Holtham, R Dunne, D Stoll

Flash flotation is a process designed to remove coarse, liberated, fast floating minerals from hydrocyclone underflow. Irrespective of liberation, coarse particles would normally remain in a grinding circuit until they are reground fine enough to report to the hydrocyclone overflow. Additionally, minerals of high density also report to hydrocyclone underflow despite being fine in size and/or liberated because hydrocyclones separate on the characteristics of both particle size and density. Dense particles continually reporting to the hydrocyclone underflow can lead to over-grinding and the production of ultra fine particles. These particles exhibit slow flotation kinetics and thus are difficult to float in conventional flotation circuits. Therefore, removing coarse, liberated particles from the hydrocylcone underflow by flash flotation has the potential to improve recovery and can improve dewatering unit operations and reduce grinding costs.The impact on the overall performance of the flotation circuit by removing coarse, fast floating minerals prior to conventional flotation is not well understood. Ultimately, predicting the overall recovery improvement provides the justification for the installation of a flash flotation cell within the milling circuit. This paper will describe attempts to estimate flash flotation recovery improvements to the overall circuit using kinetic data from simplified batch cell flotation tests combined with limn-based modelling techniques.CITATION:Stoll, D, Dunne, R and Holtham, P, 2012. Modelling the impact of flash flotation from batch cell flotation tests using limn, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 179-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By C D. Rose

A review and summary of the results of 120 coal sampling system bias tests is presented. This review supports new methodology using multivariate statistics currently being considered by ISO TC27 SC4. The current difficulties with ISO 13909-8 are explained and the logic behind the current new working draft is discussed in detail. Bias was detected in nearly 36 per cent of tests reviewed, suggesting that much improvement is needed in designing, maintaining and monitoring the performance of sampling systems in order to avoid sampling bias.CITATION:Rose, C D, 2012. Bias testing of mechanical sampling systems for coal - A review of test results and call for use of multivariate statistical analyses, in Proceedings Sampling 2012 , pp 185-192 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By C M. Ramotsabi, F Bornman, W Erasmus

Spiral concentrators are gravity based separation devices used for the preparation of coal, iron and heavy mineral ores (Wills, 1992). Gravity concentration remains the main separation method for fine iron ore and is used extensively for treating many minerals. Gravity concentration methods separate minerals of different specific gravity by their relative movement in response to gravity and one or more other forces, the latter often being the resistance to motion offered by a viscous fluid such as water or air (Wills, 2006).The main operating variables for a spiral concentrator are the feed rate, the slurry concentration, the wash water addition and the position of the splitters used to separate the tailings, middlings and concentrate streams (Sadeghi, Bazin and Renaud, 2014). Wash water is an important control variable used to wash away entrapped light minerals from the concentrate stream (Burt, 1984; Bouchard, 2001). Sadeghi et al concluded the spiral operation to be sensitive to the wash water flow addition and resultant economic trade-off. Increasing the wash water flow rate increases the concentrate grade at the expense of the iron recovery.The paper addresses the effects of dripping wash water onto the concentrate stream of a spiral processing fine iron ore. The dripping wash water system offers a low flow alternative and could possibly provide a good balance between grade and recovery of valuable minerals without using excessive water. The Multotec SC20HC/7 WW spiral was used for the experimental test work. The spiral was tested at varying solids concentrations; the wash water rate and the splitter positions were kept constant.The use of wash water at 30 per cent, 35 per cent and 40 per cent solid concentration improved the Fe grade in the concentrate by about 1.5 per cent, six per cent and eight per cent respectively. The additional SiO2 rejected by the wash water is approximately three per cent, nine per cent, and 11 per cent at 30 per cent, 35 per cent and 40 per cent solid concentration respectively. Addition of wash water is shown to have minimum effect on grade at 30 per cent solid concentration, and Fe upgrades obtained with and without wash water were found to be similar. Notable upgrades were observed at 35 and 40 per cent solid concentration with wash water. The results obtained suggest that the additional SiO2 rejection by wash water increases with an increase in solid concentration. This suggests that the benefit of using the drip system is notable at higher solid concentration. It is believed that at lower solid concentration SiO2 particles are reasonably free to move around and are possibly less entrapped than at high solid concentration.The Fe grade/recovery and solid concentration relationship with wash water showed a non-linear correlation. The Fe grade increases with an increase in solid concentration up to a somewhat optimum point and then drops as solid concentration increases further. The recovery of Fe on the other hand follows a converse relationship with solid concentration, the recovery decreases from 30 per cent to 35 per cent solid concentration and then increases again at 40 per cent solid concentration. The increase in recovery at higher solid concentration could possibly be explained by the fact that the mass yield to concentrate also increases with solid concentration. Since recovery is a function of both grade and mass yield, the higher recovery at 40 per cent solid concentration is likely due to the high mass yield obtainable at 40 per cent solid concentration.The drip system could therefore possibly offer a safe guarding against grade and solid concentration variations without using excessive water, and possibly ensure that a product within specification is maintained.CITATION:Ramotsabi, C M, Erasmus, W and Bornman, F, 2015. Optimisation of wash water on an iron ore spiral to improve grade, in Proceedings Iron Ore 2015, pp 175–184 (The Australasian Institute of Mining and Metallurgy: Me

Jul 13, 2015

A novel approach to validate size distributions obtained from bubble sizing techniques is introduced. The experimental rationale consists in verifying whether the output features the anticipated bi-modality when two uni-modal populations (ca. 0.5 and 5 mm) are mixed in a bubble column. The degree of deviation is quantified by comparing the calculated and real proportions on a volumetric basis. A sampling-followed-by-imaging technique was used to proof the concept. The results showed the anticipated bi-modality in which the real and calculated proportions corresponded with a deviation of less than 15 per cent, considered good given the severity of the test. However, the deviation was correlated to the superficial gas velocity (Jg) in the column and was consistently against smaller bubbles. Possible sources of bias are suggested.

Jan 1, 2005

By D Pateman, F de Fredrick

The Bentley underground mine, which is located 60km north of Leonora, Western Australia, is owned and operated by Round Oak Minerals Pty Limited. A high-grade Zn-Cu Volcanogenic Massive Sulphide (VMS) orebody, Bentley was discovered in 2008 with production commencing in 2012. Long-hole open stoping is employed to mine the steeply dipping ore body, and in recent years the Avoca method has been adopted. This requires all development in a particular area of the mine to be completed prior to stoping commencing in a bottom up sequence. Voids are commonly backfilled with loose Run-of-Mine (ROM) waste loose rockfill (LRF); or alternatively cemented rockfill (CRF) can be used. Stopes in the 3860 AOS and 3900 AOS panels were located below previously extracted Avoca zones, with LRF situated immediately above them. These high-grade stopes were originally designed with rib and sill pillars to maintain control of the existing backfill during extraction. Due to changing factors over time, including mining economics, alternative options to achieve full extraction of the stopes were reviewed, including: • Mining small successive full height stopes which would involve drawing a blanket of LRF down with the extracted ore (stoping under waste); • Stabilisation of the existing LRF above the stopes and implementing a primary/secondary stoping sequence, with the primary stopes backfilled using a cement fill. An assessment of these options was undertaken which determined that the second full extraction method was the most beneficial to the operation, and could be achieved using a cement grout (Minova’s FB200 grout) to stabilise the LRF in conjunction with implementing a sequence where the primary stopes would be backfilled with cemented aggregate fill (CAF). Footwall drives were developed adjacent to the rockfilled stopes, allowing for the installation of horizontal grouting conduits, as well as providing access to the top of the planned 3860 and 3900 level stopes for the placement of CAF. An interval at the base of the previously rockfilled stopes was grouted at multiple horizons to achieve the required thickness, with a comprehensive quality assurance/quality control (QA/QC) process undertaken. Primary stopes were CAF backfilled via an arrangement of downhole winzes, linking the top of primary stopes to cross-cuts developed off the associated footwall drives. CAF was delivered underground through an open reticulation network that was extended to the specific levels. Overall the successful implementation of the revised mining method effectively increased ore recovery while maintaining control of overbreak and dilution, providing significant financial upside. This was achieved while maintaining effective controls in light of the changes to the risk profile. Stabilisation of the existing rockfill has allowed the extraction of stopes to full height, including the originally designed sill pillars, representing an average 23% increase in ore tonnes on the initial design, with dilution from the stope crowns averaging less than 1%. The use of CAF in association with primary/secondary stoping, eliminating the need for rib pillars, has yielded an average 47% increase in ore tonnes compared to the base case mine design.

Mar 15, 2021

By B Taylor

The Perseverance deposit is the most southerly known economic copper/gold deposit within the Cobar gold field. The deposit is situated approximately 12 km to the south-southeast of Cobar and is essentially blind to surface with the top of economic mineralisation occurring 750 m below ground level.Based on the December 2010 resource estimate (inclusive of reserves and net of depletion) the deposit contains 3 011 000 tonnes at 6.1 g/t Au and 0.90 per cent Cu (590 000 oz of gold and 28 000 tonnes of copper). The deposit is comprised of four principal lenses, the Perseverance, Hulk, Zone B, and Hercules lenses. In excess of 90 per cent of the known resource tonnes are contained within the Perseverance and Hulk lenses. The deposit is shear related and hosted within lower Devonian rocks of the Cobar Basin. The competency contrast of rhyolites juxtaposed against sediments by the Peak-Perseverance shear is the principal control on mineralisation. Both the Perseverance and Hulk lenses are primarily hosted by brecciated rhyolites juxtaposed against Chesney formation sediments across the Peak-Perseverance shear. This faulted rhyolite sediment contact roughly defines the global orientation of the deposit. The Perseverance lens continues within the shear for up to several hundred metres beyond the extent of the faulted rhyolite sediment contact. Mineralisation within the shear beyond the faulted rhyolite contact zone is hosted by sheared silicified sediments. The Perseverance lens remains open at depth and to the south.The Zone B and Hercules lenses, which are significantly less important in tonnage terms, are hosted by rhyolite breccias within the main body of the rhyolite and appear to be only tenuously related to the Peak-Perseverance shear. Within the Perseverance lens, the presence of northeast trending high grade breccia veins developed oblique to the north-south trending shear system has led to the development of steeply north plunging high grade ore shoots within a globally north-south trending mineralised domain. These high grade shoots have limited horizontal continuity but significant down plunge extent.The presence of coarse gold and the resulting strongly skewed nature of the gold grades, in conjunction with controls on mineralisation which are not parallel to the mineralised domain, has led to predictive difficulties regarding stope performance.Strong heterogeneity of the gold content of the ore and geological controls on mineralisation which are not parallel to the global trend of the mineralisation impose a set of difficulties which sound geological control is helping overcome.

Aug 22, 2011

The Mungana group of mines, in the Chillagoe district, yielded 334,000 tons of ore giving 31,831 tons of lead, 7,907 tons of copper and 3,228,600 ounces of silver. The Girofla mine produced approximately 220,000 tons of ore, and with the Lady J ane mine supplied most of the ore from this centre. The deposit was discovered in 1888, but active development did not commence from the main shaft until 1898. A subsidiary of the New Chillagoe Railway and Mining Co. Ltd., the Mungana (Chillagoe) Mining Co. Ltd., worked the mine from 1902 until 1914, selling copper, copper-lead, lead ores and fluxes to the smelters at Chillagoe. The smelters stopped operations in 1914 when the richer ores of the Girofla had been worked out and production from the Lady Jane had ceased due to heavyground and fire. The Girofla shaft was 823ft. deep with a cross-cut at 810ft. At the 710ft. level contour drives had delineated the orebody, which had been stoped about 10ft. above the level. Except for flux ores which had been stoped only for favourable smelter tariffs, the orebody was practically exhausted above the 610ft. leveL Under company ownership the mine yielded 139,265 tons of an average grade of 4.QlYr copper, 16.2% lead and 12.5 oz. per ton silver.In 1921 the Queensland Government re-opened the mine and worked it until 1927. The North Lode (Fig. 2) was discovered almost immediately at the 100ft. level and was worked down to the 410ft. leveL The ore from this branch and the completion of the stope at the 710ft. level yielded about 80,000 tons of ore averaging 0.4 copper, 9.8 lead and 7.8 oz. per ton silver during this period.

Jan 1, 1953

Crandallite and millisite in Christmas Island 'B' and 'C' phosphate ores are rapidly decomposed by sodium hydroxide solutions at about 80QC. As these phosphates generally contain less than 1% silica, an alkaline extraction process can be designed, in which up to 95% of the sodium hydroxide used, may be recycled. The insoluble residue consists of an impure, highly reactive apatite, which in pot trials, has given good responses as a direct application fertiliser; alternatively this residue can be underacidulated to give a granular product with fertiliser potential. The hot leaching solution contains up to 95% of the alumina and approx- imately half of the phosphate from the original ore. Simple crystallising techniques have been developed on a laboratory-scale to use this leaching solution for producing smelter-grade alumina and detergent-quality trisodium phosphate. As the demand for detergents is limited, an investigation was made of the reaction between trisodium phosphate and slaked lime, derived from a high-grade New Zealand limestone occurring near Oamaru. The product is calcium phosphate, containing up to 40% P205, and less than 0.2% each of iron, aluminium and fluorine, and it should be a useful raw material for phosphoric acid manufacture. A preliminary economic evaluation of the whole process looks promising, And warrants further investigations, including pilot-plant work.

Jan 1, 1971

By H J. Dalstra

High-grade iron ore may be derived from banded iron formation (BIF) through four fundamentally different processes:1. syngenetic precipitation of chert free BIF,2. residual enrichment by removal of gangue minerals from BIF to form bedded (residual) ironore,3. mechanical erosion of iron oxide and chert from bedded iron ore or BIF and re-deposition andupgrading as detrital iron ore, and4. chemical removal of iron from BIF and precipitation elsewhere as a secondary (channel) irondeposit.Finally, the BIF itself may constitute iron ore if a high-grade concentrate utilised for pellets or sinters can be derived from it through mechanical (industrial) separation of iron oxide by means of crushing/milling and mineral separation.Historically, exploration for high-grade BIF hosted iron ores was focused on the residual (bedded) deposits and driven by supergene concepts. Exploration for detrital and channel type iron ores was mostly secondary to exploration for bedded deposits, but recently, a more focused exploration effort has led to the discovery of enormous moderate to low iron grade deposits in the Pilbara region of Western Australia. Exploration for high-grade iron ores using syngenetic concepts has been limited,but together with exploration using hypogene concepts offers the best hope of fi nding concealed deposits. Exploration for BIF sources suitable for concentrate ores commenced in the ‘old’ iron ore provinces after the high-grade resources were depleted and has only recently gained importance in Australian BIF provinces, mainly as a result of high iron ore prices in the last decade.

Jul 11, 2011

By O N. Savassi

A rigorous methodology for prediction of flotation plant performance is presented, which is based on a standardised batch flotation test called the MFT. The work is part of the FLEET program, developed by MinnovEX with the support of seven large mining firms. The methodology is divided into three key steps: direct measurement of the kinetics of true flotation in the pulp, independent of hydraulic entrainment and other froth effects in the batch cell; benchmarking of the industrial plant over a broad range of ore types and operation conditions; and model calibration to describe froth effects in the plant, with a minimal number of parameters. To date, the methodology has been applied with success at several industrial plants, encompassing copper, gold, nickel, iron, lead, zinc and coal operations. This paper includes a description of the laboratory testwork procedure and scale-up to full industrial circuits. Examples of industrial application are also presented.

Jan 1, 2005

By I Grewal, M Lundt

Dense medium separation (DMS) is one of several preconcentration methods used for early waste rejection from run-of-mine ores at relatively coarse particle sizes prior to additional milling and beneficiation. DMS has been used extensively in the coal, diamonds, mineral sands, base metals and iron ore industries to produce either a final product or as a preconcentration step. Laboratory scale and pilot test work at the Met-Solve laboratory in Canada has demonstrated successful separation and upgrading of other minerals such as lead, zinc, copper and lithium based ores using DMS.This paper reviews historical dense media systems, results from the pilot-scale multi-stage DMS Separator “Condor” system, as well as production plants and associated laboratory heavy liquid separation (HLS) test work on various minerals. The mineral systems tested included a lithium bearing ore and a fluorspar ore. Other minerals were tested but are not reported in this paper.Pilot plant test work on a fluorspar ore showed that 41.6% of the mass could be rejected to the tailings stream while 95.3% of the CaF2 was recoverable to the product stream. On a spodumene sample that was tested, it was possible to reject 55% of the mass to tailings while recovering over 90% of the lithium.In recent market conditions and with the decreasing grades in existing ores, preconcentration should be a consideration to maximise the value of certain operations.CITATION:Lundt, M and Grewal, I, 2017. Dense media separation – a valuable process for preconcentration, in Proceedings MetPlant 2017, pp 122–130 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By K Faure

At Sams Creek a peralkaline granite porphyry dyke hosts gold-bearing sulfide-quartz-siderite veins. The granite dyke intrudes Ordovician-Silurian metapelite and quartzite, and has thin lamprophyre dykes along its contacts. The mineralised veins and the granite and lamprophyre dykes have been deformed during several phases of folding, the youngest of which is Early Cretaceous. The granite has been hydrothermally altered, with early magnetite-siderite¦biotite alteration overprinted by sulfide and quartz-siderite veins and quartz-perthite-albitesiderite-pyrite-rutile¦sericite alteration assemblages. The sulfide veins are composed of arsenopyrite + pyrite ¦ gold ¦ galena ¦ sphalerite ¦ chalcopyrite ¦ pyrrhotite ¦ graphite, with minor quartz and siderite. The gold contains significant silver (up to 30.8 wt per cent) and ranges in fineness from 692 to 844. Immiscible liquid-rich fluid inclusions, in quartz protected from recrystallisation by enclosing arsenopyrite, contain carbonic liquid that homogenised at temperatures of 320 - 355¦C. The Sams Creek gold deposit is distinguished from the orogenic gold deposit type by its stockwork veining, magnetite-siderite¦biotite alteration, high sulfide content, ore mineralogy and the absence of mineralisation in the metapelite country rocks. Features of the Sams Creek gold deposit do not fit neatly into existing classifications of granite-related gold-bearing deposits. The peralkaline composition of the Sams Creek granite and the absence of molybdenite and paucity of chalcopyrite, are major points of difference with gold-rich porphyry copper deposits. The presence of a lowsulf idation-state ore mineral assemblage, carbonate alteration and carbonic fluid inclusions at Sams Creek are typical of many of the reduced granitic intrusion-related type of gold deposit. However, notable differences are: the reduced type granites are metaluminous and calc-alkaline; and Sams Creek only has high As in contrast to elevated Bi, W, As, Mo, Te, and Sb in the reduced type. The Sams Creek deposit also shows affinities with gold deposits associated with alkaline magmatism, and it appears to be a new variant of this type as an As-Au deposit associated with a peralkaline granite and lamprophyre.

Jan 1, 2004

By A Sainoki, D Fukuda, K Shioya, C Zhang, M Sharifzadeh, T Yamaguchi, S Saydam, J Kodama, C A. Amagu, Y Fuji

In an open pit mining, ensuring stability of rock slope has been one of the major challenges. As the instability of rock slopes can results in slope failures; consequently, endanger the lives of workers, affect mining operations, and often lead to economic losses. Therefore, it is practical important to study the stability of rock slopes to ensure safe, smooth, and effective mining. The stability of rock slope of about 130 m height at Higashi-shikagoe limestone quarry, which has experienced slope failures four times since 1996, was assessed. The rock mass at the quarry is consists of mainly limestone, schalstein and slate rocks intersected by clay seams of about 70 m thick at footwall of the rock slope. Previously, the effects of limestone excavation at the foot of the rock slope and shear failure due to rainfall infiltration have been investigated. Although clay is widely known to plays a vital role in the stability of slopes in engineering projects including mines, but its impacts on slope deformation at the study quarry are not adequately examined. Therefore, the present study addressed the impact of presence of clay on slope deformation at Higashi-shikagoe limestone quarry by employing both field displacement measurements and numerical simulation. Firstly, surface displacements measured by automated polar system (APS) for over eight years were analysed to understand the overall characteristics of the slope deformation. The measured results show that the displacement gradually decreases with time. The maximum displacement of about 100 mm was observed at middle of the rock slope. Secondly, the effect of deterioration and plastic behaviour of the thick clay layer were simulated using two-dimensional finite element method (2D FEM). The simulated results reveal that the clay exhibited deterioration by water contact and plastic behaviour arising from mining activities at the footwall of the clay zone. Based on the characteristics of the measured and simulated results, it was found that the displacement induced by the effect of deterioration of clay is more noticeable at the north side of the quarry whereas displacement induced by excavation is quite significant at the south side of the quarry if clay behaves as an elasto-plastic material.

Nov 29, 2022

By Norman TE

The design of composite materials for wear resistant service aims at com- bining two or more materials in such a way as to achieve unique and useful properties not generally available in any single homogeneous material. Properties and applications are presented of what might be described as a new generation of wear resistant materials, namely, metallic and part- metallic composites suitable for use in the high abrasion/moderate impact environment encountered in the crushing and screening of ore. Significant cost performance benefit can result from the use of such materials and several specific case histories are discussed. Some promising new developments, utilis- inn white iron and rubber, as yet in the field testing stage, are reviewed. Further comments are offered foreshadow- ing new composite developments, as yet untried but which appear to h,uve merit.

Jan 1, 1978

By D Laskovski, T Nguyen

Flotation surveying can be an extremely powerful means of determining opportunities for circuit optimisation and benchmarking. The type of survey employed depends heavily on the nature of the information required from the survey. It follows then that the type of survey determines the type of samples required; however, regardless of the type, the success or failure of a survey is often dependent on the correct used of appropriate sampling techniques at each sampling point. For a successful flotation plant survey it is vital that the correct samples be collected at the correct time in respect to the feed and each other. This paper discusses the current best practice sampling methods used in flotation surveying and discusses in detail the ideal sample masses based on theoretical analysis. Comparisons with JKTech’s database of real plant operations will then be made.CITATION:Laskovski, D and Nguyen, T, 2014. An investigation of current flotation survey sampling, in Proceedings Sampling 2014 , pp 99–106 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By G van Niekerk, M Wortley

Screening is a critical part of many mineral processing circuits and keeping the aperture of the screening media within specification is vital to ensure efficient performance of the processing plant. Typical ways of estimating and/or measuring the wear of the screening media vary from very subjective methods (for instance, using the human eye) to manually checking the width of a few of the more severely worn gaps with a measurement device. Subjective methods can be flawed by human error while manual checking can distort the polyurethane or rubber materials that are used in several types of screening media. All of these errors can cause either premature replacement of panels or, even worse, poor screening of the material.Metso Process Technology and Innovation (PTI) and Metso Screening Media Solutions (SMS) have developed an innovative method that measures screen aperture using advanced image processing techniques. Field trials of the device are presented in this paper, which shows the comparison between the different methods of measuring apertures. Case studies demonstrate how the system, when combined with ScreenTrack, MetsoÆs industry leading maintenance system, and screening media, is providing users with the best possible screening solutions.

Sep 26, 2011

By Gill L. F, Gleeson HB

This paper describes the development of a Computer Aided Design and Drafting based mine planning system in the State Electricity Com- mission of Victoria. The system combines a commercially available CADD system with a commercially available mining/geological package. The methodology used in the establishment of the combined system, the fea- tures of the system and the current status of development are discussed.

Jan 1, 1989

By J Player, R de Vries, E Villaescusa, H Saw, R Hassell

The use of cemented rock fill (CRF) for support of open stope walls has increased in the Australian underground mines operations over the last five years due in part to its low capital cost. In open stoping the exposed CRF masses require adequate strength and stiffness, in order to resist the forces and to limit the displacement associated with movements in the rock mass surrounding the excavations. The CRF material preparation often involves the use of large particles, either from crushed rock or from development mining waste sometimes up to 1 m in diameter. However, the use of waste rock, which has a poorly graded particle size distribution may not achieve the required minimum target strength due to segregation and large air voids within the fill mass. This paper describes the optimisation of CRF strength by either crushing the waste rock or the addition of sand to the mix. Both methods increase the level of fines in the mix design. Cylindrical samples having 400 mm diameter and 800 mm heights were prepared for uniaxial compressive strength (UCS) testing. The UCS test was determined using the Western Australian School of Mines (WASM) large-scale static test frame. The laboratory results were compared with a database of large-scale CRF strength mixed without sand from a number of mine sites around Australia. The comparison shows a significant strength development in the CRF mixing with addition of sand for a given cement percentage. Due to the higher strengths achieved by the addition of sand and the crushing of the waste material these CRF types require less cement to achieve the same strength. This has the potential to improve the overall economics of open stope mining due to less dilution of the exposed fill mass.CITATION:Saw, H, de Vries, R, Player, J, Hassell, R and Villaescusa, E, 2017. Optimisation of cemented rock fill strength for open stope support, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017