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By J. L. Nebreda, Z. Fan, J. B. Patel

"A380 alloy has been widely employed to produce thin-wall components via high pressure die casting (HPDC). During HPDC processing, there is a significant problem of property variation even with the very stable and precision automated casting procedure. The enlarged variation lowers the component performance and affects the steady and uniform property distribution along the whole component. In this study, high shear melt conditioning technology was developed and applied to the melt prior to pouring into the shot sleeve. Experimental results show that with application of intensive melt shearing, the variation of elongation was decreased from 21.8to 13.9%, and yield strength variation was reduced from5.5to 3.6%. The improved property variation is attributed to enhanced nucleation both in shot sleeve and the die-cavity, and to the improved distribution of porosity and secondary phases as a benefit of high shear induced grain refinement. With application of high shear, large number of the Spinel phase (MgAl2O4) particles with double size distribution in average diameter of 80and 300nm were formed. Due to the good orientation relationship and small misfit between alpha Al and MgAl2O4, the particles act as the effective nuclei in shot sleeve and die cavity, respectively.INTRODUCTIONA380 alloy had been widely used for produce automotive components by cold chamber high pressure die casting(HPDC) processing, due to its relative good mechanical properties and cast ability performance, and more important most of A380 ingots were produced by recycled Al alloys. Therefore, to promote utility of A380 will contribute to reducing emission of CO2and to the lightweight of automotive industry as well. When cold chamber HPDC was employed to produce the components, the mechanical properties of A380 alloy always have a distribution range (named variation herein), or in other words the properties were not stable. The reason was ascribed to the typical solidification characteristics occurred in HPDC processing. During HPDC processing, there are three steps of melt movement. The first step is that the melt was poured into shot sleeve at temperature of about 680°C, in which shot sleeve was preheated by few shots of melt filling, or by heater. During step one, the first solidification of melt was happened in shot sleeve and about 20% solid made of coarse a-Al grains was formed(Li, Xiong, & Guo, 2016).Such kind of grains will retain in the final products and deteriorate the properties variation. The second step is that the melt was forced moving forward slowly by plunger at about 0.2–0.3m/s until the liquid melt front to the inner gate of mold. The third step is that the melt moved very fast to complete the filling of die cavity and refilling the solidification shrinkage by fast movement of plunger about 2–3m/s. The second solidification was occurred in die cavity and fine a-Al grains will be formed by high cooling rate at about 500–1000°C/s. From the solidification point of view, the grain size was dominated by nucleation and growth. When HPDC was employed to produce components, the melt quality becomes the priority factor to control the solidification process as the other casting parameters were kept at the same."

Jan 1, 2018

By P. Mpofu

In this work, the modification of interfacial chemistry of colloidally stable kaolinite clay dispersion has been carried out to improve its flocculation performance and dewatering behaviour. Synergistic action between dispersion pH, hydrolyzable metal ion and high molecular weight polymeric flocculant structure type (anionic polyacrylamide-acrylate copolymer (PAM) and non-ionic polyethylene oxide (PEO)) was found to play a pivotal role in inter-particle bridging, the enhancement of the settling rate and extent of consolidation of the pulps. Flocculation with PEO led to higher settlings rates in acidic than alkaline pH, whilst for PAM, the maximum dewatering rate was achieved in the neutral pH range 6 - 7.5. Upon shear, the PEO flocculated pulps showed dramatic improvement in consolidation to 40 wt%, the extent of which was greater at lower than high pH values. For PAM-based pulps were however, not shear-responsive, lower sediment solid contents of 15 - 23 wt% was observed between pH 3 and 11. Hydrolysable metal ions, Mn(II) and Ca(II), used respectively at pH 7.5 and 10.5 in conjunction with PAM and PEO, significantly enhanced the settling rates and consolidation of the pulps. The findings exemplify the strong links existing between pH-mediated particle surface chemistry. polymer structure-conformation, inter-particle bridging and dewaterability of kaolinite dispersions.

Jan 1, 2004

By Carl-Oscar Nilsson, Åke B. Nilsson

"The embankment dam at Storfinnforsen is 23 m high and was completed in 1954. The dam has an impervious zone with timber sheet piles and a support fill of glacial till. The pore water pressure in the downstream shoulder has during recent years increased due to deterioration in the sealing function of the timber sheet piling. There is a concern that the high pore water pressure in the glacial till will cause internal erosion initiating at a thin coarse transition layer between the glacial till and the rock fill along the downstream toe. As a remedial action in order to improvement of the leakage resistance a supporting berm of coarse rockfill against the downstream slope of the dam was constructed in year 2013. In addition a new impervious seal in the centre of the dam e.g. a diaphragm wall was considered. However, after further studies and a trial stretch of 40 drains each 20 m long and diameter 0.3 m an alternative with vertical drilled drains in the downstream support was selected. A contract has now started up to drill in a similar way to treat the full length of the dam with drains. The work is in the planning to be completed in 2016.Dam ConstructionStorfinnforsen Embankment Dam was put into operation in 1954. The dam is 330 m long and maximum height is approximately 23 m. The dam is constructed with a central core zone and supporting zones of earth and rockfill on the upstream and downstream sides giving an almost symmetrical cross-section about the dam axis, see Fig. 1. The upstream slope is 2H:1V down to el. 270 and 2.5H:1V below. On the downstream side the slope is 1.75H:1V down to +269 and 2H:1V below. The core zone consists of a timber sheet pile wall with a Zone 5 of glacial till, approximately 2 m wide, adjacent to the wall on the upstream side."

Jan 1, 2016

During a period of six months in FY2018, a series of trials were conducted to compare drilling accuracy using two different methodologies and the subsequent impact this had on ore dilution. Testing was conducted at Cracow underground gold mine in Queensland, Australia. The drill rig’s existing alignment process was compared to a new technology system with the following observations: - Using the existing alignment process only 20% of holes surveyed recorded toe points within the +/-300mm (11.8in) tolerance blast-hole deviation. - The new technology was proven to limit rig alignment error, reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%. The increased accuracy reduced stope dilution by reducing over-break of subgrade ore: - Stopes drilled using the new technology recorded 62.6% less average dilution. - This contributed to an overall reduction in dilution for the full year (FY18) of 5 percentage points compared to FY17 - from 22% to 17% (a net decrease of 22.7%). A cost-benefit analysis extrapolated from the trials stipulates that if the new technology were in use for a full 12 months, when applied to FY17 full year data, a 10 percentage point reduction in dilution would represent a net 45.4% decrease, and would result in AUD8.2M (USD5.9) additional ore recovered, with AUD4.5M (USD3.2M) less spent on wasted cost of haulage and processing of diluted ore. As a result, return per tonne would increase 22%, from AUD87 (USD63) to AUD106 (USD77.1). INTRODUCTION Dilution – planned and unplanned – remains a significant cost impairment in the mining process. A series of trials were held over a six-month period in FY18 which established the cost-benefit of new technology as it applies to the alignment accuracy of production drilling rigs in underground mining, thus confirming its ability to limit drilling as one of the causes of dilution. The trials identified three underlying factors affecting drilling accuracy, measurable by blast-hole deviation surveys of planned vs actual toe data. These were; rig alignment error, collar location change/error, and in-hole deviation. The trials involved a comparison of existing rig setup processes and technology, with the new technology (Minnovare’s Production Optimiser system). The trials were undertaken in the same environment; an operating underground gold mine - Cracow Gold Mine. The comparison first revealed the extent to which rig alignment impacts blast-hole deviation. Secondly, the new technology was proven to limit rig alignment error, thereby reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%.

Jan 1, 2019

By Karl Ingmarsson

Larger mines spend millions of dollars annually on rock drilling tools, but often purchase based on historic consumption. The results vary from excess inventory to acute tools shortages. These lead to emergency sourcing, sometimes mixing products that don’t perform optimally. Boart Longyear analyzed the usage pattern of 96 thousand drill bits at thirteen different underground mining contracts, showing very high variability. The monthly standard deviation on a product level was 42%, with the highest for development and low volume bits. A new rule of thumb is suggested to carry only one month of safety stock for high volume bits, but increase to three months for low volume bits. This balance will reduce the risk of outages with less inventory. The accuracy can be improved by considering the specific conditions at each mine and reclassifying individual bits for a different safety stock level. Root cause analysis and collaborative forecasting between mines and suppliers can lead to further optimization of availability and inventory levels.

Feb 1, 2024

By Jeanne A. Zimmer, Brad Smith, Steve Viles, Andrew B. Cecala

A recent report evaluating silica exposure levels in the metal/nonmetal mining industry noted that bag packaging and loading are some of the occupations at the greatest risk. In addition to dust problems, the bag-stacking process is labor intensive, making lost-time injuries common due to back fatigue and strains. During the bag-stacking process, a significant amount of dust can be generated, mainly from product on the outside of the bags and from dust escaping the bag valve upon impact of the bag on the pallet. In an effort to address dust-exposure and back-fatigue issues, Malvern Minerals Co., Hot Springs, Ark., made two major improvements to its ground silica stacking facility. First, the company purchased a semi-automated bag palletizing system (Figure 1). With this system, the bag stacker does not lift the bags, but slides them across a metal table. Small jets of air exit through perforations in the table top (similar to an air hockey game), allowing workers to more easily slide each bag into the proper position. After each layer of bags is completed, the table slides open, and the entire layer of bags is loaded onto an underlying pallet. The table then closes, readying it for another layer of bags. After the entire pallet is loaded, the unit delivers the pallet to a shrink wrap and forklift pick-up area. In addition to this semi-automated palletizing unit, Malvern Minerals purchased an Overhead Air Supply Island System (OASIS) to lower the bag stacker's dust exposure. The OASIS takes outside air, directs it through MEASURING RESPIRABLE DUST The bag stacker's respirable dust exposure was monitored using a RAM-1 instantaneous dust monitor to evaluate the impact of the various changes on the palletizing process and dust-control equipment. The bag stacker wore a vest that held the 10-mm Dorr-Oliver cyclone, which classifies the respirable portion of dust. Flexible tygon tubing was used to connect the cyclone to the RAM-1 dust unit, allowing the bag stacker to perform the palletizing process with minimal interference. The RAM-1 measures respirable dust concentrations by light scattering with a sensing chamber. This device closely simulates gravimetric measurements when calibrated for a specific dust. This instrument is ideal for comparative evaluations, as was the case in this study. Since the RAM-1 is not an MSHA-approved instru¬ment for dust compliance sampling, the dust concen¬trations listed in this article should be used as a com¬parative value of respirable dust concentration and not to determine actual dust concentrations from a com¬pliance standpoint.

Because surface mining removes the original plant cover from the land and exposes the soil, special care is needed. Until the mined land is stabilized by revegetation, snowmelt and rainfall can pick up sediment and erode mined lands much faster than undisturbed areas. Sediment control is an important aspect of protecting the environment during mining and reclamation because without it, large amounts of sediment can clog streams, increase the risk of flooding, damage irrigation systems, harm aquatic habitat, and limit the use of water for other purposes. Stream quality can be affected many miles downstream from the mine. Before SMCRA was implemented many streams were degraded by uncontrolled sediment from mining. Sediment is controlled through careful planning and a design that incorporates a variety of measures that work together to reduce soil erosion at the mine. Disturbed areas are graded, and some areas terraced, to achieve stable slopes, reduce runoff water velocity, increase infiltration, and divert runoff into drainage channels so that it flows away from unvegetated, erodible areas. Grading along the slope contour and scarify in gun vegetated slopes with bulldozer track marks help prevent erosion by slowing down the flow of water. Runoff from haul roads is controlled by culverts and roadside ditches. Sedimentation ponds or other forms of sediment control are required at all mines to minimize the amount of sediment leaving the site.

Jan 1, 1992

By J. H. Schubert

Mintek has developed a level-control system, FloatStar, for use in flotation circuits. Instead of controlling levels separately in each unit, the controller monitors levels throughout the circuit. It can thus take account of the global effects of any control actions. A collaborative project between Mintek and Karee Platinum Mine has begun, looking at aspects of flotation control. Karee plant was chosen as the site for this work because of its good existing control infrastructure. As a first stage of the joint project FloatStar was installed. Analysis during installation and running of the FloatStar has illustrated how circuit design and measurement technology can affect process control. Severe interactions have been observed in the levels of adjacent banks. The effect of FloatStar on flotation performance was tested and an improvement in level control was observed. Similarly, a faster settling of the plant after start-ups was observed. Both the improved level control and faster start-ups lead to higher platinum recovery.

Jan 1, 1999

By S Hille, J Karageorgos

With the increased variability of todayÆs large-scale mining operations, consistent flotation performance is important to improving and sustaining overall recovery through the circuit. The Newcrest Telfer Mine has implemented advanced process control technology to obtain stable level operation and consistent mass pull in the copper rougher and scavenger flotation circuits. The final result has been an overall reduction in variability, which impacts on both copper and gold recovery. This paper describes the methodology and implementation of the improvements in control at the Newcrest Telfer Mine as being an essential part of the business for minerals processing.

Jan 1, 2007

By Alena Johnson

"Much of the copper being produced today uses heap leaching, where pure metal is extracted from the ore with a chemical process rather than smelting. This technique is deployed extensively in major copper producing areas including Chile, Peru and the southwestern United States.Copper ore is excavated from the ground, crushed and then spread in uniform layers on a pad. A slow trickle of sulfuric acid is distributed over the pile, where it percolates to the bottom and a collection point. The acid leaches out the copper, along with other minerals, which can be extracted chemically. This process can be used at large sites producing 100 kt/a (110,000 stpy) and greater.Production on a massive scaleProduction at heap-leach sites is continuous and can operate on an enormous scale. The ore is fed into a crusher to break down the large pieces, and then it moves into an agglomerator to capture the fines and create more uniform particles. While in the agglomerator, the ore is mixed with acid for the first time, helping it to bind the fines into larger particles and starting the leaching process. The treated ore moves by conveyors to a stacker designed to spread it uniformly on the pad.The size of the operation comes into perspective by considering a typical pad measures 1.6-km (1-mile) long and 0.8-km (0.5-miles) wide. Working day after day, the stacker creates individual piles or modules on the pad, each 122 x 61 m (400 by 200 ft) and 3 m (10 ft) deep. When one module is filled, it moves across the pad to the next, filling the area in one continuous pile. A completed row of modules spanning the width of the pad is a cell. Once the entire pad is covered, the process begins again laying down another 3-m (10-ft) layer, and it continues until the entire pad reaches its height limit which can be several hundred feet.Once a new module is completed, technicians lay a network of plastic pipes over the surface in a pattern similar to agricultural drip irrigation installations. The diluted sulfuric acid, called raffinate, is pumped through the pipes so it can be distributed over the module, allowing the acid to soak through the ore and leach out copper as it percolates to the bottom. At the same time, approximately 35 to 45 percent of the acid is consumed by dissolving the calcite carrying the metal in the process. The raffinate reaching the bottom is now characterized as pregnant-leach solution (PLS) since it carries the copper the company is seeking to recover."

Jan 10, 2018

By R Bose, M Bovell, G Cheong

Grinding media is a major consumable in mineral processing and therefore decreasing costs associated with its consumption is regularly considered a key goal for the minerals processing industry. Grinding media manufacturers have historically developed steels with improved wear life for their products as a way of delivering incremental media quality improvement. This has included increasing carbon levels from low-to-medium carbon steels up to the eutectoid carbon composition of 0.77% where the relationship between higher carbon and better wear performance is well understood. Producers today will regularly use grades in excess of 0.8% to further improve wear performance particularly for rolled grinding media.This paper first introduces the demonstrated relationship between this increased carbon content and improved wear resistance along with metallurgical rationale behind the high carbon production process and limitations. To test the performance improvement associated with the higher carbon steel grade, a series of Marked Ball Wear Tests (MBWT) were carried out. This paper also explores the relationship between ball properties, test methodology and wear performance and concludes by correlating increased carbon grade with a reduced consumption rate of between 3.1% and 6.1% in the tests conducted.CITATION:Bovell, M, Bose, R and Cheong, G, 2018. Improved forged grinding media performance with carbon content greater than 1.0%, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 559–570 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By F. Waanders, Campbell. Q.

This project was specifically aimed at using increased acceleration separation, as a method to optimize the recovery of gold in an ore body mainly consisting of hematite where the specific gravity of gold is much higher in comparison to the carrying material, making it possible to separate gold from other materials like silica, base metals and their oxides, usually associated with gravitation-gold-recovery-processes. The ore body investigated in this project originated from a gold reef containing a large portion of gold locked inside the gold pyrite complexes, which was mined and treated in a conventional way. After gold extraction, the material was pumped to a tailings dump and the gold extraction of this dump was investigated. In order to assemble a concentration plant setup, the head grade and size distribution of the dump and bulk sample were determined accurately. Chemical analysis and mineralogical examination were done on a representative sample of the bulk sample, to determine the chemical composition of the material. The results obtained thereof were evaluated and a pilot plant was configured. A bulk sample was processed in the pilot plant and the results were evaluated. The results at optimum acceleration forces applied, resulted in a recovery of 5% of the mass, with a gold concentrate of 90 g/t Au, which represented 58% recovery of the gold. The hematite with high specific gravity as main phase positively influenced the high acceleration separation process. It proved that if the specific gravity of particles in a suspension were increased, high acceleration separation could be applied effectively to separate much smaller particle sizes.

Jan 1, 2014

By G Kirk

Definition and delineation of in-pit ore and waste material are the most significant tasks for an open pit production geologist; adding or destroying value in the mining value chain. Anglo American’s Mogalakwena Platinum mine, an open pit operation in South Africa moving 100 Mt/a, has recognised the value of improved material definition and is in the process of changing from blasthole to reverse circulation (RC) sampling for in-pit grade control. This is aimed at obtaining more representative samples, which are required to maximise ore recovery, minimise waste dilution and to increase the accuracy and confidence of production forecasts. Early in the project, it was realised that the key risks for implementing RC grade control were related to change management processes, rather than failure of technology. Recognising the importance of this issue, Mogalakwena chose an integrated implementation approach that incorporates all stakeholders of the mining cycle in order to develop a process that delivers maximum value and is sustainable within an active mining environment. The following core goals were addressed over five phases of project implementation: extensive definition and design of integrated project implementation, comprising: project buy-in and ownership from all key stakeholders, including survey, geology, mine planning, drill and blast, load and haul, maintenance, supply chain and finance; and detailed analysis of all potential issues and possible solutions, allocated to stakeholders as part of the scoping process; optimising hole patterns and drilling procedures, focusing on delivering maximum value for minimum cost using multiple scenario analysis from borehole data and operational sequencing requirements; and evaluation of lessons learnt during project implementation in order to optimise the technical solution and operational efficiencies. Although this project is not yet finalised, Mogalakwena Platinum Mine is already providing a blueprint for the effective development, implementation and optimisation of sustainable in-pit grade control RC drilling for other open pit mines within Anglo American plc.

Aug 22, 2011

By B Upton, J Mitchell

The use of hydro scaling and in-cycle shotcrete to replace conventional jumbo scaling, mesh and bolting as the primary method of ground control for run of mine development has been investigated through extensive trials at the Waroonga mine, Agnew Gold Mining Company.These trials have progressed from investigating the productivity aspects of the method through to a three month mine-wide trial, which may yet lead to the adoption of this potentially best practice ground control technique at Agnew.Ov erseas trials and research have shown that hydro scaling results in a significant improvement in the shotcrete-rock bond strength. Good adhesive bond strength ensures that the shear strength of the shotcrete layer rather than itÆs flexural or tensile strength is fully mobilised as rock mass reinforcement.This maximises shotcretes ground reinforcement capability and it is suggested that a bolt-less fibrecrete support design is feasible using the hydro scaling technique.

Jan 1, 2005

By T Kilpatrick

Managing heat stress on Australian mine sites is a complex and enduring challenge due to the combined and variable contribution of environmental conditions, physical activities, and protective equipment. Inappropriately managed, heat stress can place significant physical strain on workers, leading to serious and chronic health issues. Additionally, excessive heat stress can dramatically reduce productivity, with 30 per cent of workers reporting a loss of productivity due to occupational heat strain. In Australia, due to increased absenteeism and reduced work performance, heat strain is estimated to have an annual economic burden of over $8 billion.

May 5, 2022

By H Kurth

High specification Prompt Gamma Neutron Activation Analysis (PGNAA) has been successfully applied to conveyed flows at iron ore operations since 2002 to representatively measure ore quality for improved quality management and process control. While the PGNAA technique has changed little since that time, significant improvements have been made in measurement capability. Elements previously unable to be measured well or at all using this technique are now measurable and one of these is phosphorus. Aluminium and magnesium are also key elements in addition to calcium and silicon in determining sinter basicity in ironmaking. Other elements measured routinely in iron ores include iron, carbon, potassium, sulfur and manganese. The benefits of representative measurement cannot be overstated as iron ore mining operations in South Africa, Europe, Australia, Asia and the Americas have discovered. The technology is applicable to any conveyed flow where elemental analysis in real time assists with quality management, from raw materials in ironmaking through to scrap steel in steelmaking and coal quality for coke-making. Major benefits are realised when raw material processing is optimised and this often includes diversion of material meeting a required quality so it can bypass unnecessary processing. This includes waste rock which can be diverted from a plant feed stream in 30 sec increments or ore that meets product quality being diverted to bypass beneficiation. Analysers are successfully utilised to identify ore types that assist with upgrade optimisation in jig plants; measuring feed, product and discard flows to also account for metal content. Product flows to stockpiles help manage production flows and stockpile qualities for different products and assist in blending ores into trains or ships to confirm specification compliance. Technologies can be used in magnetite processing but are predominantly used in hematite and goethite ore processing operations. The paper details examples of the above applications at various operational sites providing estimates of economic benefit as well as operational improvements.

Sep 18, 2023

By J. Kang

To obtain microbial cultures with the ability to efficiently leach copper ion from chalcopyrite, microbial samples from acid mine drainage sites were mixed and then subjected to mutation using sodium nitrite (NaNO2), diethyl sulfate (DES), ultraviolet light (UV) and their combinations. Mixed cultures with a much stronger ability to leach copper ion (identified as mixed cultures A, B, C, D and E) were obtained by screening on leaching media. Leaching tests showed that mixed culture E had the best leaching performance and increased the Cu2+ content by 120.5% in 20 days, compared to a control without mutation treatment. Mixed culture E grows well on Leathen leaching medium supplemented with Cu2+ (at a final concentration of 32 g/L), reaching 3.2 × 107 cells/L after 15 days, while the unmutated control culture cannot survive beyond 15 days, indicating that mixed culture E is more tolerant of high concentrations of Cu2+. In addition, continuous leaching by mixed culture E is very effective at a pulp density of 1%. These results suggest that it has the potential for industrial applications.

Jan 1, 2008

By M. Saghaeian, R. Hejazi, R. Barreiro, M. Tavousi, M. Ahadi, O. Asghari

"Banded iron formations are the major iron source for producing high grade concentrate. BIF are generally lower grade and more difficult to extract. In order to know how best to process BIF ore, it require comprehensive knowledge on ore bodies even in the early stages of the mining process. Geometallurgy combines geological and mineral processing information and allows for higher flexibility in response to changes in the plant feed when mining different parts of the ore. This can lead to economic benefits, owing to improved plant operation, yet is time consuming and correspondingly costly. The main focus of this paper work has been to develop a comprehensive geometallurgical testing framework for developing Yogi BIF low grade magnetite deposit located at Western Australia. In order to provide successful geometallurgical mapping, was collected data from several different disciplines (geology, chemistry, mineralogy) and parameters (physical properties, metallurgical response and geotechnical measurements) during drilling activities and test work. The investigation shown magnetic separation behavior of material had high variation and is most important element in the proper design of ore beneficiation plant. This paper provides an improved and efficient magnetic separation test methods used for the investigation of separation behavior and variability of the Yogi Ore deposit and evaluates their applicability and potential in the geometallurgical context. In this paper a small-scale magnetic separation has been developed that allows estimating from single pass separation test using small amounts of sample material. Verification of the evaluation method and validation was done with different mineral systems."

Jan 1, 2018

By J. Drelich

An improved experimental procedure to measure contact angle has been consolidated with coal surface preparation involving polishing with abrasive paper, alumina powder, and a cloth, followed by ultrasonic and mechanical cleaning. Specifically, the captive-bubble measuring technique has been compared with the sessile-drop technique and the former has been recommended for the examination of the hydrophobic properties of coal surfaces. Results of the research program, which is currently under way, on the examination of the effect of the nature, amount, size and distribution of mineral inclusions in coal on its wettability are briefly reviewed.

Jan 1, 1999

By C Beal, S Singh

Sensor-based bulk ore sorting is a form of preconcentration that autonomously measures and physically separates discrete bulk ‘pods’ of run of mine (‘ROM’) or primary crushed material. This case study examines the results of a full scale bulk ore sorting trial undertaken at Cozamin mine in Zacatecas, Mexico in 2019. The bulk ore sorting plant comprised primarily of a mobile jaw crusher, fixed conveyor, MR analyser, and diverter gate. Results of the trial demonstrate that bulk ore sorting could deliver a net improvement in copper metal fed to the processing plant of 6-8 per cent within an equal gross tonnage of ore. Copper metal increases were the result of improvements in mining recovery, where valuable mineralisation is recovered from marginal or sub-grade material that would otherwise be discarded as waste or stockpiled as low-grade. The increase in mining recovery more than compensates for metal losses suffered in the bulk ore sorting plant.

Nov 10, 2020