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By J Pease, P Cameron, D Drinkwater

"In the 1990s metal prices were trending in a long-term decline and the usual cost-cutting exercises were adopted. Cuts to research and development made innovation difficult and the outlook was grim. But necessity is a strong motivator, and these conditions spurred the Mine to Mill movement that optimised across organisational ‘silos’ and utilised new technology tools, innovative software and increased computing power. Many applications of Mine to Mill exploited the fact that comminution is usually the site processing bottleneck and blasting is more efficient at breaking rock than grinding. This approach sought to: understand and characterise rock breakage from mining to the milldevelop models and simulators for blast design, fragmentation, crusher and mill circuitsdevelop tools to measure in real time the particle size distribution of rocks on run-of-mine (ROM) muck piles, at the primary crusher truck dump pocket and on conveyorsensure effective communication across the silos between geologists, blast design engineers, mining engineers and metallurgists.These methods and the technology tools available in the 1990s were widely adopted at numerous sites around the world with significant benefits. Semi-autogenous grinding (SAG) mill throughput increases of 10–20 per cent were common. This was the advance the industry desperately needed. It was low capital cost; it was obvious. It was here to stay.Except, in too many cases, it didn’t. In the minerals price boom of the 2000s Mine to Mill was no longer necessary to ‘survive’, even though it was still good business. Some operations, including some of the early success stories, slipped back to old habits of optimising within organisation silos instead of across them. Fortunately, other operators still embraced Mine to Mill and developed new techniques. Mine to Mill was still successful, but not as widely adopted as we had expected it to be. Now the boom has ended and operations are again under cost pressure. Since these are the same circumstances that created Mine to Mill, it seems time to achieve the wider adoption. Since the 1990s many new or advanced technology tools are now available for Mine to Mill projects: blasthole sensors, new explosives formulations, new blasting techniques and modelling, ore tracking devices, improved image analysis to determine size, texture and colour of coarse ore, grade sensors, whole-stream simulation tools, and even more powerful computing hardware and data analysis software. If we could achieve so much in the 1990s, how much more can we achieve today when we have the same imperative, the same potential and a larger number of high technology tools?Citation:Cameron, P, Drinkwater, D and Pease, J, 2016. The ABC of Mine to Mill and Metal Price Cycles, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 349–358 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

The Mobile Miner MM130 was delivered to Broken Hill in February 1992. During March the machine was extensively trialled on the surface to test manoeuvrability, climbing ability and muck handling prior to being trammed underground in April. The first cutting test on 30 April 1992 provided promising results. The machine has undergone continual development since it arrived in Broken Hill with aims of ensuring reliability and achieving performance goals. The paper gives a detailed account of recent performance comparing this with the predicted Performance.

Jan 1, 1993

Intensive exploration for iron ore in the banded iron-formations (BIF) of the Pilbara region of Western Australia began in the early sixties and almost immediately established the Hamersley area as a major iron province. The early genetic models for the BIF-hosted ores were based mainly on macroscopic examinations of ores from the "hardcap" zone, and generally accepted a direct relationship with weathering effects on a Mesozoic to Tertiary land surface. Brandt (1964) was the first to suggest a difference in age between the high-grade hematite ores and the more common hematite-goethite types. He initially accepted a supergene origin for both, but later opted for a hydrothermal origin for the hematite ores. Apart from MacLeod (1966), the published views of the next decade reflect a largely parochial interpretation of individual ore bodies, centred mainly on supergene models but with some support for hydrothermal concepts. Except for Ayres (1971), none of the models were backed by detailed mineragraphic data. In 1976, an AMIRA-sponsored CSIRO group began a Province-wide investigation of the wide variety of ore types and BIF, with emphasis on geochemical and textural studies. The resulting conceptual model for a world-wide unified supergene and supergene-metamorphic hypothesis is generally accepted in the Hamersleys.

Jan 1, 1986

Misima Mines Pty Ltd (MMPL) operates a large open cut gold mine on Misima Island in the Louisiade Archipelago in Papua New Guinea. Misima Island lies approximately 600 km east-south-east of Port Moresby. The island is 40 km long by 10 km

Jan 1, 1994

By L Scheunis, A Van den Bulck, E Jak, K Verbeken, M Shevchenko, R Starykh, I Bellemans, P-J Boeykens

As a result of the globally increasing consumer use of electronic devices, it is expected that pressure will increase on the supply chain of precious metals. Hence, recycling of these electronics becomes increasingly important, as well as optimising the current processes. One major issue in metallurgical processes is the amount of metal that is lost into the slag. This metal loss is inherent to the production process and therefore, additional processing steps such as slag cleaning may be required. Slag cleaning can be done in electrical resistance furnaces where heat is produced using the Joule effect, making the slag’s electrical conductivity an important operating parameter. Since slags are ionic liquids, the electrical conduction happens via the movement of ions which is called ionic conductivity. However, within the presence of transition metal oxides, a second mechanism of conductivity occurs as electrons are able to hop from one transition state to another, which is known as electronic conductivity. As ‘FeO’ is a common slag component in the non-ferrous pyrometallurgical industry, both mechanisms are present, but their proportions vary with the respective amounts of the two forms of the multi-valent ions and hence, with the oxygen partial pressure. The goal of the present study is to develop an experimental set-up and methodology for measuring the electrical conductivity of synthetic SiO2 – CaO – AlO1.5 – ‘FeO’ slags at various oxygen partial pressures.

Jun 19, 2024

By Waqinwright M. S

The underlying principles of dewatering theory have recently achieved considerable practical application in the washing and dewatering of alumina trihydrate in Bayer plants. In particular, the influence on residual cake moisture contents of trace amounts of surfactant added to the wash water reveals that significant energy savings can be achieved. The influence of organic compounds produced by the caustic extraction of bauxite in the Bayer process is shown to be significant. These humic species reduce the cake permeability and the effectiveness of certain surfactants in dewatering operations.

Jan 1, 1989

From 1980 to February 1991 the Rosebery concentrator purchased ore from Aberfoyle's Que River Mine. Following the termination of the contract the concentrator reverted to treating Rosebery ore alone. Since that time it has become apparent that the circuit configuration employed was no longer optimum for zinc metallurgy. The circuit was designed to treat a difficult, slow floating sphalerite; however, the opposite was now found to be true. The sphalerite is fast floating and the circuit was cumbersome. During 1992 extensive circuit changes led to the provision of a simple open circuit flow sheet. The circuit is now easier for operators to understand and lends itself to improvements in process control. Middlings streams have been minimised, which produces a far more stable circuit. Significantly, it must be noted that the key to achieving potential results must lie in reducing variations within the process. A significant ore characterisation program has been undertaken, providing an insight into the metallurgical compatability of the ore to be mined. Using the information collected in this program, metallurgical recoveries and grades can now be predicted with a geater accuracy. Ore characterisation data suggests that an improvement from a 54 per cent zinc concentrate to a 57 per cent zinc concentrate should be achievable. By understanding the size-by-size mineral assemblage, a strategy for concentrate grade improvement has been developed. The requirements of the customer must in all cases determine the quality of the product. Pasminco is a fully-integrated zinc producer and as such significant gains can result by tailoring the concentrates to suit the Smelters.

Jan 1, 1993

A narrow (200-300m) zone of amphibolite facies metamorphic rocks underlies the Papuan ophiolite near the Musa-Kumusi divide, SW of Popondetta, Oro Province. The amphibolite rocks are bounded up-section, to the NE, by peridotite and gabbro of the ophiolite; and down-section, to the SW, by mafic greenschist, which in turn overlies blueschist facies mafic schists of the Emo Metamorphics.Amphibole compositions within the narrow contact zone show a strong chemical zonation which reflects a steep thermal gradient, with maximum temperatures >800¦C at the peridotite contact. The zonation is recorded in Ti content and A-site occupancy, relative to Al'¦

Jan 1, 1994

By Carroll D. A

The mining and minerals industry has had and will undoubtedly continue to have a considerable impact on the development of this State. For the first 60 years of its history the colony of Western Australia made slow progress; its population in 1889 being only 43,000. However, as a-result of discovering gold at Coolgardie and Kalgoorlie the Eastern Goldfields alone had a population of 25,000 by 1897. The income generated by the gold mining industry allowed the Premier of the day, Sir John Forrest, and his Government to support the proposal put forward by the State's Engineer in Chief, C.Y. O'Connor, to construct a pipeline to carry water from the Darling Ranges to Kalgoorlie ; a distance of 600 kilometres. The demand for people knowledgeable in the science and art of mineral exploitation also prompted the State Government to establish a School of Mines in the Goldfields in 1902, where it has remained ever since. The gold mines of this region have been a major source of employment for over 70 years and there is no doubt of the fact that their continued prosperity minimised the effect of the world recession on Western Australia in the 1930's.

Jan 1, 1979

The characteristics and causes of the spoil pile failures at the Goonyella Mine are described, and research results from investigations of spoil pile instability are discussed. Some effects on spoil stability of the development of deep strip mining projects are considered and recommendations are made for relevant research.

Jan 1, 1981

By Salley J, Gould WD

The stack-gas scubber effluent from base metal smelters often contain 20-100 ppm of oxidized selenium salts. Due to their toxicity, these must be removed from solution prior to release of the effluent to the environment. Many species of microorganisms including Corynebacterium diotheriae, Neurospora crassa, Candida albicans, Escherichia coli and various species of Salmonella are capable of assimilating oxidized selenium and reducing it intracellularly to red amorphous selenium. CANMET in cooperation with several companies has developed a biological process to recover selenium from dilute solutions. The laboratory, mini-pilot plant and the large industrial pilot- plant studies leading to the development of this process will be described.

Jan 1, 1990

By Neill T. J, Howarth D. F, Malcolm J. McPhersqn

For many years Isa Mine has seen the need for a continuous mining machine which will economically cut hard rock. Tunnel borers are unsuitable due to the size and inflexibility of the machine and the shape of excavation mined. The design of roadheader type machines will not permit the use of the necessary cutting technology. in 1983 a joint project was undertaken by The Robbins Company and Mount Isa Mines Limited to develop and to trial a machine suitable for cutting hard rock in an operating mine. The project was based on the proven technology of raiseboring applied to horizontal development. The Mobile Miner was fabricated and trialled in a disused quarry in the U.S.A. during early 1984. Following these trials, the machine was transported to Mount Isa and commenced mining in September that year. The initial duty was to continue the development of a decline commenced by conventional mining for a conveyor system to serve the deeper southern areas of the 1100 copper orebody. This system will permit direct tipping of copper ore to a new crusher complex and conveying of the - crushed ore approximately 2 kilometres to the central hoisting shaft facilities. The Robbins Mobile Miner MM120-3001 uses a vertical rotating cutting wheel mounted on a horizontal swinging boom to excavate a nominally rectangular shaped heading. The cuttings are collected on an apron and conveyed back through the machine. The resulting excavation is smooth-walled with no blasting damage to the surrounding rock. This provides a safer working environment than does conventional drill and blast development mining. Ground support requirements are considerably reduced.

Jan 1, 1986

By Gillies A. D S, Just G. D

The advancement of computer applications in the coal industry is focusing interest on the presentation of washability data by mathematical functions.The normal method of presenting washability data is in the form of five curves, usually filled by eye or by cubic spline functions. It has been shown that coal washability can be characterised by two basic relations: the instantaneous ash vs relative density relationship and the instantaneous yield vs relative density relationship. In a new approach to the mathematical modelling of the instantaneous ash vs relative density relationship, theapplication of the algorithm to a data set from a mine in central Queensland was successful.

Jan 1, 1991

A study is presented of the theoretically possible initiation systems for outbursts and the subsequent propagation mechanism.Previous occurrences of outbursts and their correlation to the theoretical system are described. An estimation of the energy release from two energy sources, gas strain energy and rock/coal strain energy, is presented and the relative importance of each source in the severity of outbursts. Summary: The description of mechanisms of outbursting follows the examination of these phenomena at Collinsville in Bowen No. 2 mine and at Leichhardt Colliery, Blackwater. Quantitative material contained in the paper refers to Leichhardt Colliery, Blackwater. Clearly from the work carried out to date gas release has a major part to play in the out- bursting at both of these collieries. In the case of the December 1 1978 outburst at Leichhardt Colliery energy release estimates place gas strain energy release contributing eight times the energy of that from rock/coal strain energy. Even the normal outbursts at Leichhardt Colliery appear to show this trend. Estimates of energy released are for comparative purposes between gas and rock strain energy and the values obtained may be regarded as approximate.

Jan 1, 1980

By Nolan D. P, Balales M

Over the last two years work has been undertaken within the Pasminco Metals - BHAS Zinc Plant to improve the efficiency and maintain the production capacity of the operation. The work has centred upon the installation of suitable process instrumentation to improve process control and the development of new unit operations to maintain control of the circuit water and sulphate balance. A key aspect of the new process instrumentation has been the development of an on-line analyser to monitor the total antimony concentration during zinc dust purification. As a result of changes made to the Zinc Plant in order to contain all effluent within the circuit, a problem developed with control of both the water and sulphate balance of the circuit. A new neutralisation plant to treat all cell house waste water so that it can be contained within the circuit has been developed and installed. In addition changes have been made to the existing circuit to control deliberately the circuit sulphate concentration by precipitation of sodium and potassium jarosite.

Jan 1, 1993

By M W. I Visser Æt Hooft, R C. Schimmel

Until recently the Corus IJmuiden pellet plant produced approximately 4.5 Mtpa of pellets. Corus IJmuiden is currently running a program to increase its pig iron production to 6.4 million tonnes HM per annum. The burden of the Corus IJmuiden blast furnaces consists of approximately 50 per cent high basicity sinter and 50 per cent acid pellets, both produced in-house. To accommodate the increased pig iron production, the capacity of the pellet plant needed to be increased to 5.0 Mtpa. The productivity was increased by modifications to the plant layout, which were implemented during the 2006 cold maintenance stop. In addition, the composition of the ore blends is optimised to gain productivity.

Jan 1, 2007

On Wednesday 11th November, 1970, a series of violent explosions occur-- red within No.1 Basic Oxygen Steelmak- ing (B.O.S.) furnace at the Whyalla Works of the Broken Hill Proprietary Co. Ltd., (B.H.P.) when the furnace was moved immediately prior to tapping. Water from a burnt out flux chute had flooded the bath while the furnace was tilted slightly towards the tapping side waiting to tap. Although no one was injured, dam- age in excess of $54 000 was caused to the hood and superstructure. The water hydrated the burnt dolomite refractory lining some of which sub- sequently collapsed exposing bare fur- nace shell over part of the cone.

Jan 1, 1975

By Hodkinson I, Slight M

Over the last five years Mt Leyshon has matured into a sizeable gold mine by Australian Standards. In the later part of 1990, after commissioning of the 3.5 mtpa CIP Plant upgrade, experience indicated there was potentially additional Mill capacity beyond that being utilised at the 3.5 mtpa rate. Overall throughput was limited by crushing plant performance and high operating costs resulting from the age and condition of the main crushing plant.In addition, mining was being carried out using a mining contractor who utilised relatively small, high cost mining equipment, and on-going exploration success was also indicating that the then current mine plan would result in only a portion of the available resource being exploited.

Jan 1, 1992

By C I. Edwards

Phosphorous is typically present in iron ore either in the mineral apatite, Ca5(PO4)3OH, or associated with the goethitic fraction of the ore. In this paper, we present results that show that phosphorous associated with the goethitic fraction can be removed with a heating pretreatment around 300 176;C for 1 h, followed by a caustic leach with 1 - 5 M NaOH, or a leach with sulfuric acid at pH 0.5. The heating pretreatment is considered to dehydroxylate the goethite to form a haematite intermediate phase, ‘protohaematite’, that reacts during the leach making the phosphorous accessible to the leachant. In the acid leach, ten to 15 per cent of the sample was dissolved to obtain a leach product with 0.08 per cent P. In the caustic leach, as no weight loss occurs, it is proposed that iron species associated with the protohaematite have either not dissolved or have reprecipitated at the high pH values of the leach.For an ore containing apatite as the source of phosphorous, a leach with sulfuric acid dissolved the apatite, lowering the phosphorous levels in the sample. The sample treated contained carbonate minerals (including siderite) that also reacted with the acid, and in practice a balance between the dissolution of the apatite and the carbonate minerals may be needed to minimise acid consumption.

Jul 11, 2011

Samples weighing 0·5 g are fused with sodium hydrogen sulphate, leached with 5 ml. of 4 M nitric acid and diluted to 10 ml. with water. An aliquot of the clear solution is boiled with concentrated nitric acid and then 2 ml. of a phosphotungstate solution are added. After dilution to 10 ml. with water, the solution is heated in a boiling water-bath for not less than 10 min. When cold, the solution is extracted with 2 ml. of iso-amyl alcohol and the yellow phosphotungstovanadate complex is compared with a standard series. Concentrations down to 4 p.p.m. may be analysed at a rate of 100 samples per man-day of 8 hr.

Jan 1, 1971