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By S K. Ray

Open fire in a mine gallery causes large-scale damage to property and sometimes precious lives. Such fires produce two distinct effects, the throttle effect and the buoyancy effect. These effects disturb the ventilation system of the mine. To understand the complex dynamic phenomenon of open fire and its effect on ventilation systems, a mine fire model gallery has been designed and constructed at Central Mining Research Institute, Dhanbad. Two sets of experiments at air velocities of 1 and 1.5 m/s were conducted in the gallery using coal samples from the Dobrana seam of the Raniganj coalfields. After about an hour of development of fully-fledged fire, heavy backlash, with smoke and fumes, was observed. At the time of backlash occurring the gallery was divided into two zones. In the region of the gallery from the base up to 1.4 m the airflow was normal, in the remaining upper portion the airflow was the reverse. Air quantity reduced substantially, while pressure dropped across the fire zone, the products of combustion (POC) and temperature increased during the period of the throttle effect. It has been revealed from these studies that with an increase in airflow, pressure drops across the fire zone, POC, temperature and reduction in airflow increases. This paper addresses the important design features of the gallery, the instrumentation system, the experimental procedure and assesses the effect of open fires on mine ventilation systems.

Jan 1, 2005

By H Bao, M Nehring, M Kizil, P Knights

The mining sector, a notably energy-intensive industry worldwide, is a major consumer of fossil fuels, leading to significant carbon emissions globally. The move towards electrification, coupled with advancements in battery technology, has redirected focus from traditional diesel-powered solutions to battery-powered alternatives. This paper introduces a novel mining haulage system, termed the Battery Trolley system, and examines its theoretical foundations, configurations, and operational processes. It offers a comprehensive analysis of the system’s characteristics and limitations. Through a hypothetical road simulation, the study analyses various battery mining trucks, calculating energy consumption based on force parameters and tailoring battery sizes to contemporary materials and technology. When assessing various battery truck alternatives—considering aspects such as battery size, effective payload, duty cycle, energy efficiency, productivity, and single-shift production—a range of performance outcomes and characters become apparent within the mining context. The findings indicate that Battery Trolley configurations, requiring smaller battery capacities, entail lesser compromises on effective payload. Consequently, these configurations achieve a higher duty cycle, reduced energy consumption per tonne, heightened productivity, and enhanced singleshift production capabilities compared to Battery-only alternatives. The comparative analysis of Battery Trolley with stationary charging (BT-S) and Battery Trolley – dynamic charging (BT-D) underlines that battery Trolley systems are capable of overcoming the challenges associated with battery size, thus successfully fulfilling the production demands of large truck applications in mining. This positions Battery Trolley systems as a more advantageous option for the decarbonisation of mining fleets, underscoring their potential in contributing to the sector’s sustainable evolution.

Sep 1, 2024

By S Flanagan, M M. Mete, A R. Tiryaki, M Guresci

First Quantum Minerals (FQM) operates the Cayeli underground copper mine in Turkey. In response to a lost time incident (LTI) that occurred at the mine in 2022, the mine management decided to introduce a new safety approach on-site. The initiative began with a comprehensive safety culture analysis conducted by Arti Consulting, involving focus group studies. Employees actively participated in candid discussions, sharing their insights on safety issues and offering solutions. These conversations were meticulously audio recorded, resulting in over 150 000 words collected from more than 100 employees. These transcribed narratives then underwent rigorous semantic analysis, with the assistance of a sociologist, to identify and dissect patterns of unsafe behaviour. This analysis found areas for improvement, particularly in near-miss and incident reporting, quality of safety toolbox talks and effectiveness of pre-work risk assessments. Subsequently, mine management deliberated on these insights and devised corrective actions. An emphasis was placed on involving all employees in the corrective actions through communication training, empowering them to own the decisions and changes made. These impactful measures were seamlessly integrated into FQM’s Think! Safety Program, which embodies FQM’s sensible health and safety strategy. FQM partnered with Strika Entertainment (Strika) to develop innovative visual-first safety communication tools that use illustration, animation and graphic design to simplify complex messaging into easy-to-understand edutainment. As part of this approach to safety communications, Cayeli and Strika revamped the safety toolbox talks to encourage employees to voice their concerns and receive feedback when their suggestions were implemented. The response from employees has been positive, with over 200 unsafe behaviours and conditions reported within the initial two months of launching the Think! Safety Program. Remarkably, the Cayeli Mine has not experienced any LTIs for the past 500 days as of 9 December 2023. This paper encapsulates the dedicated efforts to transform Cayeli into a safer mining operation.

Apr 16, 2024

A viable flow sheet of the sorption-flotation technology for gold recovery from low-grade ores and concentrates using powdered activated carbon modified by organic compounds as the sorbent-bearer has been developed. The powdered activated carbon, with high kinetic ability and sufficient specific area, was selected as the all-purpose gold cyanide complex-bearing sorbent which is active during flotation. To improve carbon adsorption capacity and to provide the required floatability its porous structure was filled with a quaternary ammonium compound which can extract gold cyanide complexes and render additional flotation properties to the carbon. To optimise the process and to simplify the layout, adsorption and flotation processes were carried out simultaneously in a mechanical flotation cell. The proposed technology was used for extended and pilot-plant tests of sorption-flotation gold recovery from 0.6 g/t Au final tailings and 2.0 g/t Au gravity tailings. The extended tests were carried out on Taseevskaya (Chita Region) flotation tailings, whereas pilot-plant tests were conducted on Kommunarovskaya (Krasnoyarsk Region) gravity tailings passing to cyanidation, followed by processing with filtration technology. Additional gold recovery from Taseevskaya final flotation tailings was 50.8 per cent. Gold recovery from Kommunarovskaya final gravity tailings was 92.5 per cent. Compared to the complete sludge process conventionally used at the plant, gold recovery was increased by 7.5 per cent due to lower gold losses in the liquid phase and conversion of the refractory non-cyanided metal into a carbon concentrate. This paper presents the experimental results of gold adsorption onto powdered activated carbon modified with quaternary ammonium compounds (sorbent-bearer) as well as sorbent-bearer flotation with various collectors from cyanide solutions and pulps.

Jan 1, 2005

The purpose of this study was to investigate the effectiveness of froth fl otation for the recovery of gold from the gravity tailing stream of the former Lihir Gold Limited (LGL) operation in Ballarat. The P80 of the tailings was determined by screen analysis as 1 mm, with test work conducted on as received material along with samples ground to P80 sizes of 47, 78 and 134 microns. Laboratory scale batch flotation tests were conducted at both natural and elevated pH to investigate the impact of pyrite depression on gold recovery. Results indicated that although an increase in grade from approximately 0.7 g/t to 3 g/t was achievable at a natural pH and a P80 of 134 micron, gold recovery was low at just 35 per cent. Finer grind sizes were found to have an adverse effect on both grade and recovery. Future efforts will be focused on the sub 310 micron size fraction of the tailings, which was revealed to contain approximately 85 per cent of the available gold and may be amenable to cyanidation or ultra-fine gravity treatment.

Aug 1, 2010

In the first half of this century a mining industry was developed in Indonesia under Dutch colonial rule. World War II and the subsequent struggle for independence resulted in the destruction of most of the infras- tructure and much of the data. After independence, restrictions on for- eign investment and internal turmoil prevented re-establishment of a viable mining industry until the formation of the present Government after 1965 and the enactment of sound laws in 1967 to encourage foreign investment. Rebirth of the mining industry was followed initially by slow growth, but in the 1980's, spurred by the worldwide interest in gold, Indonesia has become the focus of an intense exploration boom for gold and other precious metals. 103 Contracts of Work for gold have been awarded since 1985 with Australian companies being the most predominant. Since 1985 three new gold operations have been commissioned and another two are nearing completion. Several more are undergoing feasi- bility studies. There is reason to predict that Indonesian gold produc- tion will grow to place the country in the ranks of significant producers during the 1990's.

Jan 1, 1988

By E Jak, G Khartcyzov, M Shevchenko

The increasing complexity of ore resources and recycled materials in the feed of pyrometallurgical processes present a technical challenge to the metallurgical engineers working on maximising the recovery of the valuable elements and minimising the environmental impact of the processes. To address this challenge, the availability of computational tools that can predict the mass and energy balance in complex systems is required. Then the accurate description of phase equilibria in the complex multicomponent systems describing the chemistry of the pyrometallurgical processes becomes critical for the correct implementation of the indicated tools and facing the outlined industrial challenges. In the present study the distribution of selected elements (Pb, Zn, Fe, As, Sn, Sb, Bi and Ni) between oxide liquid and metal in the ‘CuO0.5’-CaO-AlO1.5 system in equilibrium with Cu metal at 1400°C (liquidus of CaAl2O4) was experimentally studied using the equilibration and quenching technique followed by the electron probe X-ray microanalysis of the resulted samples. The study covered a wide range of effective p(O2) over the system from 10-11 to 10-3.5 (corresponding to formation of immiscible CuO0.5-rich slag). To avoid loss of volatile elements (Pb, Zn, As, Sn, Sb and Bi), a correlation between ‘CuO0.5’ in oxide liquid and p(O2) in open system was obtained first, followed by studying the volatile elements distribution in closed conditions (Al2O3 crucible sealed in SiO2 ampoule), where ‘CuO0.5’ concentration was used as a marker to evaluate the effective p(O2) over the system. The experimental results were then used for the optimisation of the thermodynamic model parameters of the system as part of the integrated experimental and self-consisting thermodynamic modelling research program of phase equilibria in the Cu-Pb-Zn-Fe-Ca-Si-Al-Mg-O-S-(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co and Na) gas/oxide liquid/matte/speiss/metal/solids system.

Jun 19, 2024

The paper examines the possibility of applying the monolithic packing technique developed in the UK to the division of wide development drivages in Australia, so enabling double entries for longwall retreat panels to be created from shortwall units. The monolithic pack of the UK therefore becomes a monolithic partition in this proposed Australian application. A method developed for the analysis of the load development in packs installed behind longwall advancing faces is adapted and used to predict the support performance of the monolithic partition. Conclusions are made regarding partition construction and possible rates of advance.

Jan 1, 1986

By Hanley J

Coal winning in the Latrobe Valley exceeds 45 mtpa uses a small number of Bucket Wheel Excavators and high speed conveyor systems. While this equipment offers many advantages in the production cycle, incorrect use can lead to low productivity and risks to the safety of the operators and equipment. The mining equipment is of high capital value and easily damaged when used outside the correct operating range. In the extreme case, this can result in total machine collapse, having major implications for personnel safety as well as production and costs. With an active productivity improvement program in the Latrobe Valley in the last two years resulting in a 50 per cent reduction of personnel, many experienced operators have retired. Mine management are facing the urgent need to rapidly train new operators to maintain high productivity levels and reduce the risk of accidents to personnel and high capital cost plant. With the assistance of the Central Gippsland College of TAFE a Certificate Level course has been developed for open cut operators. The course covers all essential training needs for the Latrobe Valley mines. The training is developed from National Competency Standards, allowing transfer of skills, and is flexible to suit other enterprises. It has been written for self-paced learning with the total job understanding, and to have competency-based learning outcomes, training tasks and assessments built-in to modules. With the introduction of this new training program, management is convinced that the element of risk within the mine will be significantly reduced. For these reasons it is an ideal training model for other enterprises.

Jan 1, 1994

The production of copper by the Outokumpu direct blister process commenced in July 1988. The problems and incidents encountered in commissioning the main smelter equipment are outlined. Early difficulties were encountered in process control, hot metal handling, dust buildup in the off gas handling equipment, waste heat boiler tube failures, foam over of hot metal into the waste heat boiler and failure of ancilliary equipment.

Jan 1, 1989

By R Higashi, D Maruoka, T Murakami, Y Iwami

The ironmaking industry consumes a large amount of fossil fuel derived carbon as heat source, reducing agent of iron ores and carburising agent of reduced iron. Although the demand for drastic decrease of carbon dioxide emission, carbon is an essential element for smelting process of molten iron. The carbon recycling ironmaking process by circulating CO has been already proposed to achieve carbon neutrality. However, the production of molten hot metal is not considered in this process because sufficient amount of carbon does not dissolve in reduced iron by CO. Therefore, our group has suggested a new carbon recycling ironmaking process which can produce hot metal. In this process, free carbon and iron carbides produced by carbon deposition reaction using metallic iron as a catalyst are used. It is known that only Fe3C is obtained as iron carbide by using CO gas, however, Fe5C2 is also produced by adding H2 gas. The composite agglomerated with these carbonaceous materials and fine iron ore (Deposited Carbon-Iron oxide Composite: DCIC) is reduced and melted in a furnace. It is reported that Fe3C in DCIC accelerates the reduction reaction and melting of the composite. In this study, the effects of iron carbides and free carbon on the melting behaviour of DCIC are investigated. Fe3C, Fe5C2 and free carbon were produced by vapour deposition using porous iron whiskers and CO-CO2-H2 gas. These were agglomerated with hematite reagent at a certain ratio to prepare DCIC samples with and without Fe5C2. The samples were heated up to 1300°C in inert atmosphere. The DCIC containing Fe5C2 completely melted and iron nuggets were obtained after the experiment. This behaviour was not observed in the composite without Fe5C2. This indicates that using Fe5C2 is more preferable than Fe3C for molten iron production using DCIC.

Jun 19, 2024

By I Swane, R Rait, A Robertson

Geochemical assessment of mine waste materials prior to commencement of a proposed mining operation is a fundamental component of mine feasibility studies and the regulatory approvals process. Static and kinetic geochemical test methodologies are widely used to predict the geochemical nature of mine waste materials and to develop strategies for managing potentially æhostileÆ materials. These data can also be integrated with data from other fundamental studies such as hydrogeology to predict specific environmental outcomes and potential impacts at mine closure and post-closure.A case study is presented for a proposed open pit gold mine in Mongolia, which illustrates how geochemical, hydrogeological and groundwater quality data can be used as part of a geochemical modelling process to predict the final pit lake water quality over time. A series of static and kinetic test geochemical test programs were completed and acquired data integrated with hydrogeological and groundwater quality data provided by the proponent. A widely used geochemical modelling program (PHREEQC) was used to develop the geochemical model and predict water chemistry in the pit void after mine closure. Sensitivity analyses were completed to explore the effects on the model output of groundwater to leachate water ratio, pit wall rock type and climate.Modelling has indicated that pit void water should be pH circum-neutral at mine closure and should remain within Mongolian and World Bank water quality guideline limits under the modelled simulation most likely to occur in the field. Final void water salinity is expected to increase eight fold over 14 years after end of mine life due to a continuous flux of salts (particularly sulfate salts) into the pit lake whilst the pit lake volume will remain relatively constant due to evaporation and a slow recharge rate. Dissolved metal and sulfate salt concentrations in pit water are also predicted to increase over time and could be moderately elevated compared to applied water quality guideline values. Some of the metal concentrations, however, may be lower as these would be expected to precipitate at circum-neutral pH and greater. Recommended additional assessment work on the project when mining commences includes determining the magnitude of adsorption and co-precipitation of metals occurring in the pit void water/sludge system.CITATION:Robertson, A, Rait, R and Swane, I, 2013. Geochemical assessment of mine waste materials and prediction of final pit lake water quality at a proposed gold mine in Mongolia, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 165-170 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

DURING a period extending over about the last two and a half years, the performances of various types of rock drills in use at the mining department of the Zinc Corporation have been recorded as closely as possible. The main objective was the collection of sufficient data regarding internal water-feed hammer drills, when used for the same class of work as the older type reciprocating drill, to enable a decision to be formed on the following points:(1) Whether internal water-feed, hammer drills could efficiently perform the work previously carried out by reciprocating drills without excessive repair cost to the former.(2) If so, was it good policy commercially to eliminate the reciprocating type completely, writing these off together with the accompanying spares, accessories, and solid drill steel, and replacing with internal water-feed hammer drills, with lighter fittings, and the requisite amount of hollow drill steel.(3) What were the best types and makes of hammer drill for different classes of mining work(4) What was the economic aspect of the introduction of the principle of internal water feed to every type of machine throughout the mine.Prior to the strike of workers in May, 1919, Ingersoll-Rand E47 31-in. reciprocating drills had been used for stoping and for the major portion of driving, cross-cutting, and similar work. The accompanying columns and fittings were all 4t in. The drill steel used was solid octagon. Up to 1916 these machines were also used for winzing, after which time jackhamers were more successfully employed. These latter were of the usual types, varying in weight from 40 to' 46 Ib. Ingersoll BCR 430, Holman No. 2 spool valve, Sullivan DP33,. Waugh Clipper 55. These machines were all dry head; the drill steel was hollow hexagon, shanked.

Jan 1, 1923

Fluidised Bed Combustion technology has expanded since the first fluidised bed boiler steamed in 1974 with 58 companies currently supplying units. In Australia the market has been in small boilers and the goal of a limited attendance coal fired boiler has been achieved. On the world scene, the major incentive for development has been emission control with sulphur capture and low NOX. The potential of significant reduction in plant size is encouraging development of pressurised fluidised bed combustion.

Jan 1, 1987

By Meyer T

Sunburst PCF (Penetrating Cone Fracture) technology has recently undergone extensive underground field trials at Leinster Nickel Operations, Western Australia. Trials with the Sunburst machine started in September 1994 and continued through to December 1994 during which approximately 130 metres of tunnel were developed. The Sunburst technology was used to excavate sub-levels through ultramafic nickel ore for future sub-level caving operations at the Perseverance nickel mine. The Sunburst machine demonstrated reasonable instantaneous advance rates, however, there are still a number of future developments/design changes which need to be addressed prior to the PCF technology being trialed again in a production environment. This paper benchmarks conventional drill and blast at Leinster against the Sunburst Excavator machine performance within similar tunnel dimensions and rock conditions. In addition to productivity and cost information; environmental considerations, support and labour requirements are also discussed. Problems with the current machine design are highlighted and possible future design changes are suggested. The Sunburst machine could be a suitable technology for advancing development through weak to moderate rock conditions and may also reduce overall support costs. With the potential for automation and the ability to reduce rock damage into the development tunnel walls, it is proposed that the Sunburst machine warrants further consideration.

Jan 1, 1995

By Lee G, Stitt P

The term "industrial minerals" covers a vary wide field. However in Australia this field tends to be characterised by the follow- ing: (1) Relatively low unit values. (2) Product specifications can be exacting compared to the metalliferous field. (3) Product specifications often have to be tailored to the needs of the end user. (4) Beneficiation plants tend to involve low capital outlays relative to the metalliferous field. However they often have to produce products'to a range of specifications. (5) Technology often influences what can be considered as reserves. (6) Because of low unit values industrial minerals tend to be relatively cost sensitive. This is particularly the case in regard to transport. (7) Location of deposits near to major urban areas (markets) dictates a greater pressure on ecological aspects. (8) In Australia there has been a tendency to vertical integration largely due to the restricted market available. Reserves assessment is shown to be critically dependent upon the above Factors.

Jan 1, 1979

By M P. Sandy, J B. Albrecht

"Narrow vein mining can be loosely defined as mining operations involving orebodies with a true thickness of less than 4 m. Some authors have limited the term to steeper-dipping orebodies where the ore will rill under gravity. However, ænarrow veinÆ can also legitimately refer to some of the flatter orebodies, such as many of the platinum, chrome and gold deposits of Southern Africa, and several in Australasia including Bullen (at Norseman), Sunrise Dam, Telfer (Patterson, 1993) and the famous æflatmakesÆ at the Emperor Gold Mine in Fiji (Gordon and Harmse, 1993). Where the orebody dip is less than about 40¦ additional effort is usually required to remove the broken ore, including the use of scrapers, hydraulic monitors or remote-operated excavators (Tombs, Buckingham and Hancock, 2008).Working in such narrow orebodies presents particular operational and geomechanics challenges. A range of mining methods have been developed or adapted to exploit narrow orebodies including:cut-and-fill,narrow vein bench or longhole stoping,Alimak stoping,shrinkage stoping, and methods for shallow dipping orebodies (including Airleg and mechanised methods).The paper discusses some of the advantages and disadvantages of each method with a focus on geotechnical aspects including mining sequence options, stress management, ground support requirements, dilution and recovery.CITATION:Sandy, M P and Albrecht, J B, 2012. An overview of geotechnical issues in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 185-194 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By C O. Gomez

The bubble size, together with the gas rate, determines the bubble surface area flux in flotation machines and, therefore, impacts directly on the kinetics of flotation. Understanding the variables that influence bubble size is one of the keys to understanding flotation recovery. Surprisingly, these relationships are poorly understood, largely due to the difficulties associated with gas dispersion measurements in industrial environments. The McGill gas dispersion sensors (bubble size, gas rate, gas holdup) are capable of reliably making such measurements. This paper reports on a study, using the McGill sensors in a 0.8 m3 Metso RCSTM pilot cell, which investigated the effect on bubble size of frother type and concentration, gas rate, temperature and rotor speed. A Denver laboratory cell was used to investigate the effect of elevation above sea level. Frother concentration proved to have the predominant influence on bubble size, and the effect of frother type can be normalised as a function of the critical coalescence concentration (CCC). Measurements made at many plant sites worldwide are compared to the model developed using the Metso RCSTM unit.

Jan 1, 2007

By B M. Patterson, A J. McKinley, M E. Grassi

Large-scale column experiments were undertaken to determine the effect of a step decrease in groundwater pH on metal remediation by bioprecipitation. Metal contaminated groundwater at pH 5.5 was amended with ~1 g/L of ethanol in one column using a polymer mat ethanol delivery system to promote bioprecipitation, while another column was left unamended and used as a control. Sulfate reduction and zinc removal were observed after eight weeks. Zinc removal was observed in the zone of sulfate reduction, indicating precipitation as ZnS, while, copper was removed in the denitrification zone. Once steady state bioprecipitation of zinc had been established, the pH of the metal contaminated influent groundwater was decreased stepwise from 5.5 to 4.25. As a result of the change in pH, a significant increase in copper concentration was observed in both columns. In the ethanol column, the zones of denitrification and copper removal migrated up the column, while both sulfate reduction and zinc removal ceased. Bioprecipitation of metal contaminated groundwater via sulfate reduction was shown to be an effective remediation strategy for zinc removal. However, this in situ biological remediation process was sensitive to changes in groundwater pH.

Jan 1, 2004

By D P. Blair

The theme of this conference is blasting productivity. This article only considers the technology aspect of this theme, and in particular, the collection and analysis of experimental data. In many cases, field trials are set up to collect data on variables such as fragmentation and vibration with the aim of comparing different explosive products and/or blast designs. An important aspect of such trials is the collection of sufficient data to draw sound conclusions. In this regard, there is no doubt that the scatter in real data is the root cause of all problems of obtaining misleading results due to an insufficient number of trials. This article shows that the typical one-off trial has a high probability of producing misleading information, which could be considered to be worse than having no information at all. Assuming that sufficient data has been collected, this article also highlights the methods that can be used to make the most of that data. These methods include the application of appropriate statistics that are dependent on the nature of the scatter in the data, and the use of some of the more recent filtering and spectral approaches that can be used to reduce the noise in measured blast signals and increase the resolution of their spectral characteristics.

Nov 8, 2011