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The economic viability of many Southern African massive mining operations is threatened by excessive dilution. In many operations currently in progress, some stopes are experiencing as much as 115 per cent waste ingress reporting to drawpoints. This paper examines the magnitude, causes and types of dilution and presents a set of general principles for the control of dilution in massive stoping operations.

Jan 1, 2000

By A K. B Opitz, M Becker, J L. Broadhurst

"One of the key drivers of geometallurgy is to define the ore characteristics and their variability to build a geometallurgical model. The inclusion of waste rock properties and their variability is just as important, given that the generation of acid rock drainage (ARD) poses one of the most significant environmental challenges facing the mining industry. Formed through the oxidation of sulfide minerals in the presence of oxygen and water, ARD generation is exacerbated through the regeneration of lixiviates by naturally occurring iron- and sulfur-oxidising micro-organisms. In order to manage the potential risk of ARD pollution, timely, accurate, reliable and robust characterisation and prediction of the ARD potential of waste material is critical from an early stage in the mining process.This study demonstrates the use of the biokinetic-accelerated weathering test developed at the University of Cape Town to characterise the ARD potentials of gold waste rock samples under microbial conditions. These tests are performed in conjunction with standard characterisation tests to provide an indication of the potential for ARD generation under both chemical and biological conditions. Results provided information regarding the relative rates of acid neutralisation and acid generation, with the contribution of specific minerals to the observed behaviour considered through use of a detailed mineralogical assessment. Overall, the addition of the biokinetic test to the current geometallurgical characterisation and prediction toolbox will allow for relatively rapid assessment of the bulk kinetics of ARD generation.CITATION:Opitz, A K B, Becker, M, Broadhurst, J L, Bradshaw, D J and Harrison, S T L, 2016. The Biokinetic Test as a Geometallurgical Indicator for Acid Rock Drainage Potentials, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 183–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By JSrvinen A, Yll÷ E

At Cominco's Zinc Refinery at Trail, British Columbia impurities are removed from zinc sulphate electrolyte by a two-stage purification process using zinc dust. Copper, cadmium and thallium are removed in the first stage whereas cobalt is removed in the second stage. Cobalt removal kinetics are affected by soluble antimony and copper additions to the electrolyte. This study was focused on the kinetics of cobalt removal by zinc powder cementation. Experimental variables included copper and antimony concentrations, pH and temperature. Common organic additives employed in zinc plants were studied to determine potential interactions with the cobalt removal process. Cementation products obtained from laboratory experiments and plant practice were studied using SEM. A number of significant results were obtained: 1. Copper and antimony ions were sustantially removed from solution during the early stages of the cementation reaction (within the first 15 minutes). Cobalt cementation kinetics are slow and follow a first order kinetic regime. 2. A drop in the cobalt removal rates can be correlated with a rise in the Eh of the slurry. 3. Ligninsulphonate, Percol 351 and animal glue at levels of 2 mg/L significantly impede cobalt cementation.

Jan 1, 1993

Gold mineralisation at the Enterprise Mine, 230 km south of Darwin, occurs within folded and metamorphosed sediments of the Lower Proterozoic Burrell Creek Formation adjacent to the Cullen Granite. The mineralised zone, which occupies an area of approximately 800 m x 300 m is local- ised by a moderately tight, upright symmetrical anticline which plunges shallowly southwards. The anticline has been disrupted by numerous faults on which the maximum movement is 40 m. Gold is associated with quartz and sul- phide veins which are present as saddle reefs, inter-reef veins and fault controlled reefs. it occurs within the veins or their alteration haloes, either as free gold (2 - 50 per cent of total gold content) or intimately associated with sulphides, principally arsenopyrite and Pyrrhotite.

Jan 1, 1984

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

Jan 1, 1990

By Sakai S, Suga S, Bisque RE

Soil gases were collected on activated charcoal, analyzed by computerized mass spectrometry and treated with multivariate statistical pattern recognition to determine the diagnostic geochemical signature associated with the Okuaizu Geothermal Field in Japan. From this a geothermal model was developed and compare to 175 "unknown" samples in a 250 m spaced grid over 30 1Qn2 mapping the areas with a matching geochemical character. Faults and fractures were generally located by the presence of high molecular weight components. Following the initial survey, the faults in two specific areas were precisely located by a second survey with samples at 10-30m spacing. Where earlier geochemical surveys had placed anomalies 1-2 Km northeast of the geothermal center, the fingerprint survey accurately mapped the system and detected several faulted zones. It was not misled by hot springs located away from the geothermal System.

Jan 1, 1987

By N Takamatsu

The environments surrounding the iron and steel industry have changed greatly in recent years. Reported in this paper are the technologies adopted by the Japanese iron and steel industry to fititself to change in global steel demands, degradation of iron ore and coal, prolonging service life of the facilities and requirements of energy saving. In addition, innovative technologies for CO2 emission control in iron making processes are also discussed.

Jul 11, 2011

WMC Limited, owner/operator of Olympic Dam, the worldÆs largest underground uranium mine and the fourth largest underground copper mine has now completed an expansion that has been classed as a benchmark in the mining industry. To achieve a production increase from 3.4 to 9.25 Mtpa from an underground mining operation in two years was a major challenge, it was essential to review the overall materials handling system from æthe face to the stockpileÆ. The challenge was two-fold:How to deliver 30 000 tonne of ore per day to the processing plant, from a single underground mine? To provide the processing plant with a consistent metallurgical feed. This paper traces the transformation from the old to the new materials handling system at Olympic Dam.

Jan 1, 2000

By M G. Shaw, M A. Rhamdhani, S P. Singh, A R. Duffy, B Eisenbart, A K. Shukla, G A. Brooks

The field of astrometallurgy is a growing area of study. Metal production on the Moon is likely to begin in less than a decade as major space agencies such as NASA (National Aeronautics and Space Administration) and CNSA (China National Space Administration) are preparing to construct permanent lunar bases. The utilisation of regolith to generate oxygen and metals is expected to be important in the development of a sustainable lunar habitat. This paper provides an overview of potential metallurgical processing methods for lunar conditions, emphasising the impact of lunar factors on slag chemistry. The interaction between regolith and the extracted metals, as well as their impact on slag composition and refractory performance, are critical considerations in metal production on the lunar surface. The initial research on lunar metallurgical technologies is focused on oxygen extraction and Fe-Si alloys are reported as the by-products of these processes. This paper delves into the fundamental thermodynamics associated with the carbothermic reduction of lunar regolith. Thermodynamic analysis using the FactSage™ ver 8.2 software package indicates that the Fe-Si alloy can be produced as a metallic product from the lunar regolith at temperatures ranging from 1400°C to 1600°C under terrestrial conditions. However, under ultra-high vacuum conditions (3 × 10-15 bar) on the Moon, the required operating temperature for producing ferrosilicon would be significantly reduced. Thermodynamic modelling results indicate that under lunar vacuum conditions, Fe-Si alloys only exist as solid phases at lower temperatures below 650°C. At higher temperatures, both Fe and Si are expected to be present in the gas phase. In this work, the carbothermic reduction of the Lunar Mare Simulant (LMS-1) is conducted under terrestrial conditions. The findings indicate that the process can readily yield Fe-Si alloys with 7–10 wt per cent Si at 1600°C. Additionally, energy dispersive spectroscopy (EDS) analysis of the resulting Fe-Si alloy indicates the presence of phosphorus up to 1 wt per cent.

Aug 21, 2024

By S J. Neethling and, S J. R Simons

In this paper the effect of humic substances (natural surfactants), electrolytes and solid particles on bubble coalescence, and as a consequence on froth stability, have been investigated. In this study two bubbles of equal size were formed and forced to collide using a novel experimental apparatus. The interactions were recorded by a high-speed camera, the images of which helped to determine the coalescence frequency and the coalescence time, as well as the mechanisms of the interactions. Two types of humic substances were used, along with three different electrolytes. Humic substances appeared to have a considerable effect on bubble coalescence, while the effect of electrolytes was minimal. Moderate and high hydrophobic glass spheres were used between two bubbles. Very hydrophobic spheres promoted fast bubble coalescence, while moderate hydrophobic spheres had no effect. Data of coalescence frequency and time is presented, as well as images of the coalescence events. The coalescence frequency was used to validate a parameter, Pf, known as the film failure frequency, used in a simulation model to predict foam height in a gas-sparged vessel. Predictions determined using Pf were then validated by experimentation.

Jan 1, 2005

An exploration and preliminary mine design contract was undertaken in Thailand to establish whether adequate lignite resources existed for the addition of future power generation plant through to the year 2000. The lignite ranges in heat value from 14 to 24 MJ/Kg (air dry basis) and occurs in 2 major seams consistituting measured reserves of 536 Mt (with an ash cut-off level of 45 % on an air dry basis) and a strip ratio of 4.1 bank cm/t. The paper describes the pre-planning, programming, equipment used, project management, logistics and exploration methods adopted to undertake the contract in a monsoonal area using Australian drilling and geophysical contractors.

Jan 1, 1983

This problem is seen as being central to a number of peripheral problems. Of these, the following are considered to be of major importance: 1. Reserves. Changes in Quality. Depths at which they occur. The effects of catchment and water storage areas. The effects of urban development. 2. Environment and the compat- ibility of mining and preparation of coal. 3. Transportation of Coal. J. tabour.

Jan 1, 1976

By E M. Wightman, C L. Evans

A recent survey of mineral processors undertaken as part of the International Mineral Processing Council (IMPC) Education Commission identified mineralogy as one of the key skills required for mineral processors (the other key areas being comminution, flotation, physical separation, sampling and extractive metallurgy). Past experience in a number of operations has shown what can be achieved when the data outputs from mineralogical tools are coupled with people with the right skills who can transform the data into actionable information. This paper reviews what has been done successfully in plant operations over a period of more than four decades and gives examples of a range of applications with both long and short-term objectives. The examples demonstrate the usefulness of mineralogical data – both basic and complex – in optimising mineral processing operations, whether the data are applied in a simple analysis or in more complex modelling. Similarly, the examples show the range of options available for operations to access the mineralogy information they need – through in-house experts and equipment based in centralised technology centres, through on-site equipment and experts or through external laboratories and consultants.The examples from industry highlight the huge potential benefit of including mineralogy as an integral part of operational best practice and raise the question of why more operations do not utilise what should be readily available data. Successful application of mineralogical data requires skilled people to generate relevant data of the required quality, together with skilled people to interpret the data (this may be the same person). And, as in any project, corporate recognition of the value of this approach to best practice is required to ensure continuing support. With fewer university courses providing courses in process mineralogy to undergraduate mineral processing engineers and chemical engineers, there is an increasing lack of knowledge about what mineralogical information is needed, how to get the required data and, equally importantly, how to turn the data into useful information.CITATION:Evans, C L and Wightman, E M, 2018. Understanding minerals in mineral processing – the basics and beyond, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 363–376 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Hagan T. N

Quite apart from economic considerations, the following performance parameters must be considered when selecting an explosive for a particular blasting operation. 1. total energy yield/kg, and more particularly, strain energy/kg and bubble energy/kg of charge 2. charge weight/m of blasthole 3. sensitivity of the charge 4. water resistance of the charge The effective division of an explosive's total energy into strain energy (SE) and bubble energy (BE) is explained as is the influence of each energy component on blast results. Because some rocks require a high strain energy for effective breakage, while others are most satisfactorily fragmented by bubble energy, values of SE and BE are more meaningful than those of total energy. Unfortunately, our extensive knowledge of the effects of certain variables on total energy has not yet been completely supplanted by the influence of these variables on SE and BE values. Relative SE/kg and BE/kg values are presented for a range of explosives. The 'charge density of ammonium nitrate/ fuel oil (ANFO)-type explosives is essentially constant throughout the length of the charge; because of their compressibility, slurry

Jan 1, 1974

In 1980 Pancontinental Mining Limited decided that while the Jabiluka uranium project was still a major focus of the company's efforts some diversification was necessary. At this time it was decided to include precious metals in Pancon's exploration and acquisition objectives. As a result the now Paddington Gold tenements were acquired, explored and developed. Today, it rates as the 6th largest gold mine in Australia and at an expanded throughput of 1.2 million tonnes per year of ore it will produce about 110,000 ozs of gold per year. Following extensive exploration activities by Pancon's Exploration Division the Operations Division continued with development drilling finally proving up a reserve of about 8.4 million tonnes at an average grade of 3.2 g/t. An in- house preliminary feasibility study was followed by a two phase feasibility study by Davy McKee. This resulted in a recommendation to the Pancon Board of Directors to develop Paddington with an annual throughput capacity of 875,000 tonnes. This paper describes the acquisition, exploration and development of the Paddington project. It goes on to

Jan 1, 1986

A brief history of the significant haulage truck feature changes and the factors that influenced those changes during the 60's and 70's provide a basis for forecasting the changes that can be expected in the 1980's. A review of the impact factors and changing requirements that currently exist that will create changes. Define the critical requirements of a successful haulage truck design and discuss the availability of bigger engines and better electric drive componetry to provide deeper pit capability and improve reliability. The Unit Rig Trolley Assist System to provide improved productivity and diesel fuel savings and an economic analysis to evaluate the Trolley System is covered. The Unit Rig Automatic Truck System for a driverless truck is covered in concept and discussed from the point of view of the experience in a test in a New Mexico mine. INTRODUCTION A good basis for trying to forecast what is going to happen in the future is to go back a little bit in history, to see what the influencing elements were in different periods of time as a foundation for the forecast. INFLUENTIAL FACTORS IN THE 1960'S If you look at the truck development that occurred in the 1960's, there were some identifiable factors that give us insight. (See Fig. 1) Several things happened at the beginning of the 1960's. Mechanical drive haulage trucks were introduced that were

Jan 1, 1982

By Leahy G. J, Moxon N. T, Nicol S. K

Experimental work is described in which extremely dilute aurocyanide liquors are treated with novel surface-active complexing agents to produce a hydrophobic aurocyanide species. Subsequent aeration of these liquors causes accumulation of such species at the air-water interface and the aurocyanide complex is transferred to a froth concentrate. A detailed performance assessment of this process is made and this knowledge used in the design of a pilot plant facility. Early results indicate the feasibility of the selective recovery of aurocyanide ions from reclaimed residue dam water (approximately 0.2ppm Au) with upgrade ratios of the order 180:1. A further study was made applying ion flotation to the recovery of gold from a carbon-in-pulp (CIL) feed liquor (approximately 1.0ppm Au). The probable economics of this process compared to conventional CIL processing is also described. Successful development of countercurrent ion flotation for concentrating solids-free gold solutions may offer a lower cost alternative to existing gold ore processing technologies, or in more secondary applications such as concentrating dilute gold solutions or heap leach runoff. The technology may also have more generalised applications to other heavy metal process- Ing.

Jan 1, 1991

By Marshall T. E, Finfinger G. L

Gulf Coast domal salt mining operations have had sporadic encounters with methane gas emitted without any warning. In virtually all confirmed cases, the methane was localized in methane enriched zones. In a few cases large quantities of methane were expelled rapidly with salt outbursts, resulting in dangerous methane concentrations. Estimates of methane liberated by face blasts in methane-enriched areas is needed in determining how much air should be supplied to the face for proper dilution. A relationship between the gas content of salt samples collected from the face and the amount of methane liberated would be helpful in estimating how much methane will be produced by a face blast. Little is known about the layering or stratification of methane in large area-low velocity airways. This publication reports on three tests conducted by the Bureau of Mines which monitored the immediate return air of four faces during blasting. The test locations were in a methane gas-enriched section that had previously experienced two large outbursts and many smaller ones. A comparison was made between gas content values of face salt samples from the dissolution test and the gas liberation quantities. The characteristic movements of the methane in a large room with low air velocities were charted. This will help to better understand the factors involved in proper placement of methane sensors as a warning system.

Jan 1, 1988

By Doyle P, Mulroney D

The Cassidy Shaft was sunk to access the Mount Charlotte and Reward Orebodies below the Flanagan Fault. The 1,184m deep shaft is concrete lined to 6.5m diameter for its full depth. The initial 590m was excavated by stripping into a 1.8m diameter borehole and hoisting the broken material through the existing mine. The remaining 594m was excavated by conventional shaft sinking methods. The shaft was sunk through 3 existing plats and an additional 8 plats cut. 1,800 tonnes of steel and 8 cables were installed during the furnishing of the 4 compartments.

Jan 1, 1985

In October 1993 it was decided to undertake the fourth phase of mining at Big Bell. This decision followed the exhaustion of open pit reserves in January 1993. Two stages of mining were proposed for the new underground mine. The initial stage would mine the remnant ore, consisting of the rib and crown pillars and lower grade ore on the hangingwall and footwall side of the old open stopes, which were mined from the 1930s to 1950s. Most of the old open stopes were backfilled with either deslimed mill tailings or development mullock, both of which were economic to recover. However, the mineable ore from this resource was difficult to evaluate. The second stage focused on mining ore outside the remnant areas and was initially proposed as a Core and Shell method under a caving hangingwall. This method has since been superseded with sublevel caving, in part due to the very high and deviatoric stress conditions encountered at Big Bell and the relatively long mining cycle required for open stoping. The problems and challenges discussed in this paper will cover the identification of remnant ore reserves, dewatering the old workings, and remnant mining.

Jan 1, 1998