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By BLAKE DAWSON WALDRON

I must acknowledge my strategic adviser, Mr Lance Grimstone, who contributed to the development of this paper, and collated the text and figures.

Jan 1, 1994

The Telfer Underground sublevel cave (SLC) Operation is located approximately 850 m below surface. The cave was designed to propagate through an old decline which was initially used to monitor the cave. There was a requirement to install air blast plugs at two locations in the old decline in order to isolate any potential air-blasts from the active workings in the event of the rock mass collapsing into the cavity. There was a further requirement for an air-blast plug in another section of the mine where there was a risk of the cave intersecting an old workshop and providing an air-blast pathway through an abandoned incline. The design criteria for the plugs was that they should withstand the design air blast loading, be free draining, cost effective and easily constructed with the mining expertise available on site. A plug consisting of grouted mullock was considered robust and least challenging to construct. For the purpose of estimation of maximum air pressure on plugs, it is supposed as a worst case that the rock above a cave falls as an airtight piston onto the top of a muck pile, forcing air into it and also mine workings intersected by the cave. Airflow through the muck pile is governed by Ergun's equation for turbulent flow. In a time-stepping integration scheme, transient air pressures and velocities are calculated according to equations of thermodynamics, in the cave and at intervals along intersected drives by means of a finite difference spatial discretisation. The ability of plugs to withstand computed pressures is assessed by finite element elastoplastic analysis. This paper outlines the rationale for potential air blast loading, calculation of transient air pressures, plug design and analysis of plug behaviour. The plug construction method is also discussed.

Nov 25, 2010

By Faidel VV, Yushina TI, Yagodkina NG, Yatsimirsky AK, Chanturiya VA

Among the problems of the flotation of sulphides by the thiol collectors is the dependence and varieties of the flotation starting with the time and oxygen contents in the slurry. For sulphides, the flotation stage follows after the electrocatalytic oxidation of the collector with oxygen on the surface of the conductor minerals. The necessity of the oxygen for sulphide flotation (Plaksin and Bessonov, 1957) is in accordance with a corrosion model of a collector surface sorption (Salamy and Nixon, 1954). As Golikov and Nagimyak (1961) showed, the sulphides possess catalytic activity which provides the autoxidation of the xanthates in the sluny to the dixanthogen. This stage can be rather protracted, which limits the speed of the total process. Disulphides constitute important collectors for the sulphide flotation and the optimal degree of the xanthate oxidation is about 20 per cent for different ores (Abramov, 1978) or, following Chanturiya and Nazarova (1977) the surface compositions for various sulphide ores are different and an optimal oxidation degree is variable from five to 25 per cent according to the ore nature. The optimisation of the surface composition is possible by application of the dixanthogens, or by a partial chemical, electrochemical, or catalytic oxidation of xanthates (Desains, 1847; Schall, 1896; Vigdergauz, 1989). According to Rand (1977) and Vigdergauz (1991) sulphides possess different catalytic activities for oxygen electroreduction. In neutral solutions, for example, the following decrease in the order: FeS2 (Fe,Ni)9S8 CuFeS2 FeS; Cu5FeS4 Cu2S; PbS (Vigdergauz, 1991). For the cases of low catalytic activities of the sulphides, the preflotation oxidation of xanthate could be useful to optimise the process kinetics.

Jan 1, 1993

PIP is regularly engaged in businesses where Greenfield Capital Projects are under- delivering on the expected business case. In most of these projects, we can identify that rigorous review has been carried out on the design and financial cost elements and substantial reporting is maintained to Boards on progress versus plan of project completion and cost. However, in all sites of this nature that we have worked at, the planning, design and execution of the operational elements or æwiringÆ of the organisation have fallen short and resulted in significant extra cost or opportunity cost (lost tonnage or quality) during start-up. When compared to the amount of planning and resources that have been poured into the capital side, the ledger on the æwiringÆ side is typically fairly sparse. This presentation outlines the importance of running a disciplined, rigorous process to prepare the human and wiring side of a start-up to ensure rapid start-ups and put the site on the pathway to high performance. It gives an outline of the rigorous process PIP has used with projects to ensure excellent start-ups.

Jan 1, 2006

By I Jabou, D G. Blazak, L C. S Hogarth

The R70 test is a good indicator of coal reactivity to oxygen and is commonly used to provide a rating of propensity for self-heating. Tests performed by The University of Queensland Spontaneous Combustion Testing Laboratory have resulted in the development of a large database that shows the impact of coal quality on this parameter. From these results it is possible to infer an R70 value, which can be used to gain an appreciation of the intrinsic coal reactivity before it is even tested. However, any interpretation of R70 values must consider the influences of coal rank, mineral matter and moisture content to provide a better understanding of the spontaneous combustion risk of a particular coal.

Jan 1, 2005

By B Mohanty, D Zwaan

Systematic near-field vibration monitoring of stope blasts was carried out in a large, deep underground mine. A total of 31 production blasts were studied in order to investigate the effectiveness of existing blast designs. This involved the vertical retreat mining method, which requires drilling a raise bore or blasting a slot raise (typically 1.22 m in diameter) using large diameter boreholes (165 mm). The diagnostic technique employed multistation near-field monitoring of blasts with high-g (100 g) and high-frequency (>10 kHz) triaxial accelerometers. The amplitude of the vibrations is correlated with the strain energy transmitted from each explosive deck. The results showed that more than 30 per cent of the explosive decks contributed little energy to the rock breakage process in these blasts, and an equal number contributed only inadequately. These findings are indicative of serious blast malfunctions. The problems can be traced to inadequate deck blast design and possibly to drill hole deviation. The various causes for such malfunctions are discussed and remedial measures suggested.CITATION:Mohanty, B and Zwaan, D, 2015. Assessment of underground production blast designs and blasting performance, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 607–616 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Nikaido M, Kanda Y

A rotary type separator has been developed which separates particles on the basis of their shape. This separator was applied to a particle size range of about 50 - 120 ¦m, and to our present knowledge may be the smallest size range ever to be separated. A theory of the separation is given based on the difference of an adhesive force of the particles: the adhesive force between spherical particles and plate is more powerful than that of irregular shaped particles for the same particle size. These facts have been ascertained by the measurement of an adhesive force by a centrifugal method. US and Japanese patents have been obtained on this separator, which consists of a borosilicate glass cylinder of 150 mm outside diameter, 120 mm in width, and an AC electromagnet. The samples used in this study were mixtures of spherical glass particles and non-spherical shaped glass particles. The results are summarised as follows. In the case of mixtures of spherical particles and irregular shaped particles in the weight ratio of 1:1, the spherical content of the spherical product became 70 per cent - 75 per cent, and in the case of 3:1, the content became 87 per cent - 90 per cent, as the result of one separating operation. However, for a mixture of somewhat rounded particles and irregular shaped particles of weight ratio 1:1, the rounded content varied between 58 per cent - 73 per cent. The feed rate of the particles mixtures was about 0.3 g/min. Newton's Efficiency was 20 per cent - 60 per cent. The separator may find application in shape separation of ceramic powder, metal powder or industrial diamond powder.

Jan 1, 1993

At the Waikato North Head Ironsand operation, NZ Steel Mining Ltd is using a Bucket Wheel Excavator û shiftable conveyor mining system to excavate Titanomagnetite bearing sand and clay. The system utilises two Bucket Wheel Excavators with a two level shiftable bench conveyor and common trunk conveyor to deliver the material to a processing plant. The system was commissioned in November 1984 and has proved itself to be a high capacity, low cost method of excavating. Techniques of handling high sand faces have been developed and the conveyor layouts are going through a process of change to cope with the variable geo technical conditions and remain within: the characteristics of the excavators. The safety requirements for operating the system have been of a high standard and the experience has increased the confidence of the Company and the Mines Department Inspector's, for the first Bucket Wheel Excavator Mining system in New Zealand.

Jan 1, 1986

By N Winkelmann

Underground coal heating is a significant hazard in some coal mines. The broad principles of how underground coal heatings occur is reasonably known, however the technique for locating the heatings in often inaccessible goaf has been proved to be difficult. Since 2002, CSIRO, with the support of the Australian Coal Association Research Program (ACARP) has been undertaking investigations to apply and develop innovative surface-based radon technique for locating the underground heatings in Australia. This paper presents the progress of the investigation.

Jan 1, 2005

By A S. Derrington

In some parts of Australia, mine air cooling may not be needed until a depth of 1300 m below surface is reached. In other locations, it may be essential at a depth of only 300 m below surface. The reasons for these differences are multifaceted. This paper discusses the main factors and describes a simple method to assess whether or not mine air cooling will be required. The method uses a graphical relationship that considers depth below surface, geothermal gradient, surface climatic conditions and directness of the mine intake routes. This relationship has been developed, tested and refined over a period of more than ten years using data collected from most of Australia’s deeper metalliferous mines. The method provides a ‘first-pass’ indication of whether more detailed cooling studies may be needed. Perhaps more importantly, the method’s underpinning by benchmarking against other mines improves confidence in the assessment results. Like any empirical method, the context must be understood and this aspect is also discussedCITATION:Derrington, A S, 2014. Will your mine require cooling?, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 181–186 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

Mine site rehabilitation is the repair of the disturbance caused by mining on the immediate mining area and also on the surrounding environment. The long-term objectives of rehabilitation can vary from simply returning an area to a safe and stable condition, to restoring the mined land to a state as close as possible to its pre-mining condition, capable of being self-supporting and having a beneficial final land use. This paper investigates the importance and benefits of environmental planning, in particular for rehabilitation, and how input into daily operations can allow mining to progress with limited impact on the surrounding environment. It will also identify some of the key mistakes currently made during mining which could be averted by implementing prior planning and incorporating environmental consideration into daily operations. A number of rehabilitation opportunities will also be detailed for the different stages of the life cycle of a coal mine.

Jan 1, 2007

By Noller B. N, McGill R. A

The Alligator Rivers Region has been the scene of one of Australia's most intensive environmental monitoring efforts since the current generation of uranium mining was mooted in the 1970s. Prior to mining, the local environment and the nature of potential impacts were not well known. The initial monitoring programs therefore included large baseline characterisation and research components. After some 15 years, water, soil and sediment monitoring programs have been reduced to a fraction of their early size, as the mining and natural systems became better known and characterised, and the actual nature of the environmental impacts were established. Modem techniques allow much more rapid and thorough identification of chemical species and elements of concern, allowing much more focused monitoring programs to be designed. In the 1980s data collection was emphasised at the expense of interpretation, and monitoring programs were maintained at much higher levels than were in fact required. It is now clear that investigations are important and should be distinguished from monitoring programs, and that the timely interpretation of investigations and implementation of recommendations can greatly reduce the effort and expense that can be involved in a monitoring program. Monitoring programs based on a sound understanding of potential environmental impact may then be efficient and cost-effective, yet provide sufficient information to assess the environmental impact of mining, guide further environmental protection measures when problems are detected, and demonstrate compliance with regulatory requirements.

Jan 1, 1994

By Robertson K. S, Hunter T. C

AEG-Elotherm's electromagnetic dosing channel, or Eldomet, is a recent invention enabling the transport and metering of molten metals. The development of a reliable refract- ory lining, and the use of suitable construct- ion and operating techniques has led to the successful application of the Eldomet for casting copper anodes at Copper Refineries Pty. Ltd.

Jan 1, 1974

By Q Liu

Open stoping is one of the widely adopted methods in underground bulk mining. In this method, fanned or parallel holes are often drilled from a top sill down to a sublevel in the ore zone and blasted ring by ring into a stope for excavation. A mass stope blast may involve blasting rock from multi-level drift rounds and displacing the muck to specific locations in order to allow safe and easy access for ore removal. This paper presents a strategic mass stope blast that took place at a large lead and zinc underground mine in eastern Canada. The blast consisted of more than 800 holes drilled in six blocks from three different sublevels. The challenge lay in the control of ground vibration and muck movement using precise timing to complete the blasting within 6.5 seconds. During this time span, sufficient voids were created in each level to allow the muck to move from the upper to the lower levels in sequential order across the six mining blocks without bridging. This paper describes stope blast simulations using a discrete element computer code for modeling blast-induced rock displacement as well as the application of electronic detonators. These detonators provided the means to accomplish the desired firing sequence including a drop raise blast at the start of the mass blast. The modelling concept is also described in the paper.

Jan 1, 2005

By H Zhang, M Karimi, M Hassan, S Saydam, B Li

With the prevalence of Mine Internet of Things (MIoT), different types of sensors have been widely deployed in mine sites for environmental monitoring and operational management. Currently, sensors in mine sites are mainly powered by cables or batteries. However, the deployment and maintenance of a power supply network can be difficult and expensive, and batteries have a limited lifespan. The vibration energy harvesting (VEH) technology can be used to provide power for lowpower sensors in mine sites. This presentation briefly introduces three widely used VEH methods (ie piezoelectric, electromagnetic, and electrostatic). The performance of a commercial electromagnetic energy harvester (ReVibe model D) is evaluated based on the vibration of a lab vibrator (3 g, 50 Hz) and an idling SUV automobile (0.3 g, 25 Hz). Experimental results indicate that a ReVibe energy harvester can generate adequate electricity to power a sensor, and its power output depends on the load resistance as well as the vibration frequency and amplitude of vibration sources. To apply VEH to mining applications, this study also analyses the characteristics of vibration sources at the mine site based on the vibration data collected from various operating machines in a coal handling and preparation plant (CHPP). The vibration analysis results indicate that all the measured vibration sources in the CHPP can generate stable and abundant vibrations, characterised by substantial amplitudes (up to 5.55 g) and low dominant frequencies (ranging from 14 Hz to 25 Hz), which are sufficient for VEH.

Sep 1, 2024

The paper continues an account, begun in a previous paper, of experimental work carried out by the author whilst a member of the metallurgical staff at the Cockle Creek Works. The general method of the description of the plant and works practice adopted previously has been followed.The paper is a short account of the methods used in and the results of an investigation of the fume losses from the various parts of the plant.MEASUREMENT OF VOLUMETwo independent methods were used. The first depended on a number of pitot-tube measurements of velocity. These readings were taken in the stacks leading from the various furnaces at a considerable height above the ground so as to obtain as regular conditions as possible at the points where the readings were taken.Three openings were made in each stack and the pitot tube inserted into each opening in turn and readings taken at the centres of imaginary areas of equal size. The average velocity in the stack was thus obtained.After four tests had been made at the smelter stack, which removed the gases from all blast furnaces in use, the centre of velocity of the gases for each test was calculated and was found to be practically constant in position. The previous procedure was varied in subsequent tests on this stack by taking a succession of readings at the centre of velocity instead of at various points...

Jan 1, 1925

By Casley G. E, Pritchard J

A single slurry fed fluosolids roaster was chosen to replace six multiple hearth roasters in the Copper Smelter at Mount Isa as part of the overall program to increase production from 100 000 to 155 000 tonnes blister copper per annum. The paper describes factors influencing the choice of the unit, problems encountered during the commissioning and details of the present roaster operation.

Jan 1, 1974

By A Sinuhaji, H Kalangi, T B. Setyoko

Ore fragmentation at the DOZ block cave mine is highly variable, both as a function of rock type and column height of draw. Initially, the mine was constructed and equipped with limited capability to handle drawpoint oversize material. Significant issues with drawpoint availability and achieving overall mine production targets resulted. A suite of secondary sizing tools was added to the mine equipment fleet over a one-year time frame. Although significant oversize continues to be experienced, use of the correct secondary breakage tool for each particular oversize or hang-up occurrence has resulted in increased drawpoint availability, production rate, draw compliance, and operator safety. Currently, a range of secondary breakage techniques is being utilised to size material for delivery to the primary crusher. Run-of-mine material (3) is directly mucked to ore passes fitted with grizzlys that have one-metre square openings. Ore containing small boulders (>1 m3, 3) is loader-trammed to ore passes fitted with rockbreakers. Medium-sized boulders (>2 m3) accessible from the drawpoint are drilled with Sandvik Tamrock Commando drills. Boulders hung-up within the drawbell are drilled and charged with a Sandvik Tamrock Secondary Breakage Unit. Compacted, fine-grained muck is blasted utilising 55 mm cartridge powder concussion bombs.

Jan 1, 2005

By S H. Sie, R Seetharam, K Naito, T Takagi

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medicallhigh-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnS2), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

Longhole open stoping was introduced in the zinc-rich 'B' lode at New Broken Hill Consolidated Limited (NBHC) during 1968. Since then one longitud- inal and a series of transverse longhole open stopes have been developed. The longholes are drilled using Gardner Denver airtrac drilling jumbos and the broken ore is loaded from drawpoints and transported to chutes using Wagner ST5 scoop- trams. The holes were drilled from sill stopes 160 ft apart. The width of an emptied transverse longhole stope was successfully widened by blasting rings of blastholes drilled parallel to the stope wall. Proposed stope and pillar designs for a series of transverse longhole open stopes were assessed using a method of finite element analysis, applied to a longitudinal section through the area. Blastholes have been surveyed for dip and bearing using an Eastman borehole survey camera. The data produced has provided the basis of a study of blast- hole deviation. Deviation of boreholes is considered to be the major cause of the formation of benches in longhole stopes.

Jan 1, 1971