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This paper outlines the role of commissioning in the project cycle, shows how to get organised for commissioning and describes the principal commissioning activities. Emphasis is placed on appointing key commissioning staff early in the project to coordinate the preparations for commissioning and on detailed planning and tracking to ensure that the required commissioning activities are performed satisfactorily. The management of safety during commissioning is reviewed.

Jan 1, 2005

Commercial explosives range from pure emulsions to pure ANFO, with blends of these providing interesting alternatives: energy is often adjusted through addition of aluminium, or the control of density. The energy rating of explosives is derived chiefly from detonation codes, which are used to derive expressions for the internal energy change of the detonation products as they do work under expansion. While all codes used for this purpose work on the basis of Ideal detonation, it is common knowledge that commercial explosives operate in the Non-Ideal domain, which affects the mode of energy delivery to the environment. However, since Ideality represents the foundation from which actual performance evolves, it is valuable to examine the intrinsic energy release of a formulation before attempting to understand the influence of Non-Ideality. In examining the Ideal pressure profile of fundamental formulations, remarkable correlation has been found with field performance, and this increases understanding of the influence of various formulation modifications, especially in regard to the stage at which energy is released, and the effect on rockbreaking. This work has emphasised the value of attempting to understand and define better the non-ideal detonation process.

Jan 1, 2001

In a previous study, various pyrite depressants were examined to improve the flotation performance of a copper-sulfide ore. Optimal results from this study were used to examine the effect of elevation on recovery and grade. Tests were conducted at elevations of 3350, 1735, 610 and -760 metres, consisted of five repetitive experiments for statistical analysis, and were performed both with and without airflow control. Tests were also performed in a glove box at Montana Tech to mimic the pressure conditions. Results indicate that both recovery and grade are dependent on pressure via bubble size and airflow suggesting that pressurised flotation cells should be considered for operations, particularly those at high elevation. Economics are extremely favourable for implementation because ensuing capital expenses are inconsequential with minimal time for return-on-investment.

Jan 1, 2005

By K Orth

The volcanic successions that host massive sulphide deposits are diverse in composition, facies types and facies relationships. They also show a variety of spatial and temporal relationships to mineralisation. In many examples, such as the Koongie Park Formation in Western Australia, the host succession includes more or less conformable syn-volcanic sills with peperitic contacts. Such sills can be an important source of heat for fluid circulation, influencing patterns of hydrothermal alteration and the location of co-eval and later mineralisation. The impact of syn-volcanic sills on the host succession depends in part on the initial porosity and permeability of the enclosing facies. The special properties of glassy pumice û being highly porous, permeable, and reactive û allow pumice-rich facies to preferentially focus hydrothermal fluid flow. However, the same properties promote early alteration and porosity reduction. Hence, the diagenetic and compaction history of pumiceous facies strongly influences their potential to host massive sulphide mineralisation. In contrast to pumice, dense glass has relatively low porosity, at least initially, and does not compact. Non-vesicular glass is a major component of submarine lavas, syn-volcanic intrusions and some volcaniclastic facies. However, especially in submarine settings, dense glass is commonly intensely perlitically fractured soon after eruption. The fractures greatly increase the porosity and permeability, locally accelerating diagenetic and hydrothermal alteration. In addition to false pyroclastic textures, altered perlite may exhibit false porphyritic textures. Silica- or feldspar-altered perlite kernels surrounded by intensely altered phyllosilicate domains can resemble phenocrysts in a fine grained groundmass.

Jan 1, 1999

Two key elements in the design of a pastefill or high density backfill system are the preparation of the backfill material and its distribution underground. This paper examines these two areas. Owing to the essentially impervious nature of total mill tailings, preparation of pastefill and high density fill from current tailings involves a physical dewatering process. There are currently three methods available for this process: Vacuum or pressure filters. These represent the ætraditionalÆ approach to the preparation of pastefill. Paste production storage mechanism. This is a thickening/storage mechanism developed with the specific objective of producingpaste/high density backfills. Fluidization. This system utilises silos fitted with simple dewatering devices and nozzles. Recently developed by CANMET, it provides the simplest and most economical approach.This paper describes and compares the three preparation methods, from a practical and an economic point of view. Once the pastefill/high density fill has been prepared and binder added, the backfill must be distributed underground into the stopes. A fundamental factor in the design of a distribution system is the rheology of the material. No two materials will exhibit the same properties, and a sequence of rheological and related testing is required prior to the completion of the design of the underground distribution system. This paper covers the testwork normally required and discusses the fundamental design parameters of pastefill distribution systems. The final section of this paper summarises the use of pastefill at three mines in Canada.

Jan 1, 1998

By S S. Kanchibotla, S Morrell

In recent years there has been a growing recognition of the impact that mining practices have on the efficiency of mineral processing operations. Head grade, dilution, particle size distribution and their variability are known to have a significant effect on the throughput and recovery achieved in mineral processing plants. Improved process monitoring and modelling have provided the opportunity to identify and quantify some of these impacts and to define very significant incentives to optimise the overall operation from the mining face through subsequent comminution and processing. The Julius Kruttschnitt Mineral Research Centre has been undertaking research to optimise æMine to MillÆ performance through a major AMIRA research project and through individual research contracts with mining companies. This work has resulted in a broad range of field and laboratory experience in terms of both the challenges and the opportunities encountered when tailoring blasting operations to suit the overall æMine to MillÆ production chain. This paper describes the objectives of æMine to MillÆ blasting to optimise the system of rock breakage involved in the blasting, crushing and SAG milling of hard, brittle ores. The design of such blasts falls outside the conventional envelope of experience for most engineers and requires the consideration of some critical factors if the objectives of such blast are to be met and some of the potential problems are to be avoided. Experience to-date has also found that the quality of implementation is critical to the success of æMine to MillÆ blasts.

Jan 1, 1999

By Stevenson C. H, Lynch A. J

The reasons for choosing autogenous grinding for the new Warrego concentrator of Peko Mines N.L. are discussed and the ores to be treated in the concentrator are described. The mill was designed on the basis of pilot tests carried out at Cobar and the performance of the mill has been most satisfactory both in its metallurgical and mechanical aspects. An empirical technique has been developed to predict mill performance for change in feed rate or feed size and a mathematical model of the mill is being developed for simulation and control work. The weight and size distribution of the mill load was determined at one set of operating conditions for use in the mill model.

Jan 1, 1974

By AJ LYNCH

Broken Hill metallurgists have been responsible for some of the most important developments in mineral processing technology. These occurred mainly in two periods, 1902 - 15 and 1955 - 70. Mineral flotation was developed as an industrial process during the first period and this happened in two stages, the recovery of zinc minerals from the tailings dump accumulated during the gravity concentration of the oxidised ores and the selective recovery of galena and marmatite during flotation of the primary ores. During the second period fast accurate analytical procedures were developed to provide rapid assessment of process performance, and new means of controlling the process were devised which improved throughputs, grades and recoveries. These technological successes were due to the skills of the metallurgists and the commitment of the companies. They brought large financial returns. They were achieved under difficult circumstance. There are important lessons to be learnt from these successes.

Jan 1, 1992

By D Laurence

Mining cycles have come and gone and with them there have been dramatic swings in the levels of interest and student entry into minerals-related education programs, hence graduate supply to the industry. So what is the problem? These trends will keep happening and the industry will keep on keeping on – or will it?This paper discusses recent trends in Australian minerals education programs and some international examples, together with some of the more recent initiatives taken by both the minerals education sector and the industry, such as the Minerals Tertiary Education Council (MTEC) and MEA. The real problem is that things will not just keep going the way they have over recent decades – there will come a time when there is no longer a supply of minerals academics available to provide the educational programs; and universities will simply shut down subcritical mass mining programs and invest in the much more lucrative programs such as commerce, law, medicine, etc. By the time this starts to happen it will be at least ten years too late for any last-minute reactive response by industry, if they were to try and avert such a consequence. International experience with mining programs bears out this scenario quite clearly.It is therefore timely for industry individual mines and mine management to take a much more strategic look at their role in the education sector. Sustainable mining also means sustainable minerals education – without one, the other will not function over the long-term. There is a pressing need for long-term strategic buy-in by industry into the education sector – not just for the good times, but also through the tough times. This means much more than a scholarship here or there, but includes such commitments as major industry-university research partnerships; collaborative recruitment initiatives and much more. The paper will discuss a range of such issues, problems and opportunities to address these important issues through strategic, comprehensive, long-term commitments by industry and equally significant and appropriate responses by the education sector. We care – do you?

Mar 21, 2011

By A McEwan, J Masters, C A. Jackson, A Catanzano, V Sharp, M Millen, S Rainey, S J. Spencer, G Roberts

A passive acoustic emission (AE) monitoring system has been developed and trialled on two M10000 IsaMillsTM. The analyser detects AE stress waves generated by grinding media impacts with the mill liner during mill operation. Locally propagating stress waves can be detected on the exterior liner surface using strategically mounted broadband accelerometers.The analyser has been developed into a robust commercial prototype system, and has been designed, installed and commissioned with Xstrata Technology at two mineral processing plants.A six-month field trial showed large-scale variation in AE power signature with process conditions. Analysis of the enveloped AE power output demonstrated a strong correlation with mill process conditions – more specifically grinding media relative loading, feed pulp density, feed volumetric flow rate and feed type.Placement of accelerometers along the length of the mill body provided key information on the grinding media relative deportment. The enveloped AE power detected by the mill body, discharge pipe and bearing housing sensors all captured information strongly correlated with mill operating parameters and process state.The prototype analyser demonstrates suitability as a long-term online tool for stirred mill performance monitoring, and potentially for optimisation and control, in beneficiation plants.CITATION:Jackson, C A, Spencer, S J, Masters, J, Sharp, V, McEwan, A, Rainey, S, Catanzano, A, Roberts, G and Millen, M, 2014. Monitoring of M10000 IsaMill™ process performance by passive acoustic emissions, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 241–254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Richards RG, Cross MS

The development of alluvial mining, processing systems and associated gravity separation technology over the last 30 years is largely linked to the mineral sands industry. Attention has been focussed on Australia in these areas of mineral resource development and technological Advancement.

Jan 1, 1986

By D K. Weatherley, A N. Mainza, I Govender, L M. Tavares, M S. Powell

It is understood that rocks do not instantaneously transport along a grinding mill and are consequently not perfectly mixed, but this is conveniently overlooked in mill modelling. A lack of understanding of the transport phenomenon and the difficulty of modelling realistic transport in a complex tumbling system, contribute to this. Visual observation of segregation in AG and SAG mills and measured lag time of mill response to changes in feed provide evidence of the influence of axial transport within mills. Incorporating this lag in dynamic models should underpin dynamic simulation of milling circuits for design and for model-based control. Limitations and errors in predicting the influence of increased power via mill length versus diameter, inability to predict pebble production, and a lack of the differential in residence time across rock sizes and competences, all contribute to inadequate design prediction that can be especially acute for large Autogenous mills. Examples of dramatically under – and overloaded pebble regrind circuits and the inability to predict pebble load in AG milling discouraging the application of this energy-efficient option, point to the need for predictive modelling of breakage by competence linked to transport through and out of mills. Incorporating progress in granular flow and mixing, coupled to computational advances enable models to be based on complex breakage and transport models at high spatial resolution. This allows mechanistic models to simulate thousands of times faster than real time, opening the door to more accurate mill design, including dynamics in process simulation and to live simulation for process control – all with advanced mechanistic models. The value of grasping this opportunity is not easily refuted.

Aug 24, 2022

By J J. Hanhiniemi, M S. Powell

A ‘Variable Blend and Rates’ model is developed for SAG mills which extends upon the JKSimMet® Variable Rates Model. Similarly, a ‘Variable Blend Residence Constrained Perfect Mixing’ Ball Mill model is also introduced, also extending upon the existing JKSimMet® model. These models are used in conjunction with JKSimMet® while employing external technical programs. The technical model is then used to inform an economic model described elsewhere in Hanhiniemi and Powell (2022), which calculate operating and unit costs based on operating conditions, design, and ore characterisation. The SAG and ball mill models include constraints beyond those in the JKSimMet® models. The SAG model constraints include Size Specific Energy (SSE) verification, charge weight limit, and assessment of the impact of media to ore composition in the charge using the SAG Charge SSE Model developed in this paper. The ball mill model includes residence time, volumetric capacity, and SSE verification constraints. These models are applied to Cortez Gold Mine in the processing of two very different ore types and their blends; ‘Horse Canyon’ which is softer in coarser sizes and competent is fine sizes, and ‘Wenban’ which is competent at coarser sizes but softer in fine sizes than Horse Canyon. Horse Canyon also has a finer run-of-mine size distribution then Wenban. The application of the model at this site included undertaking five surveys at varying blends. The behaviours of the blends and individual components is then studied in the SABC circuit. A nonlinearity is observed with throughputs increasing with blending. The newly developed modelling approach captures these responses. Controlled blending based on ore competence-by-size and size distribution was implemented by the site, which then realised significant improvements in throughput without any capital cost (Ntiamoah et al, 2020). The modelling developed in this paper is then compared to existing practice, and the new method was found to provide improved fidelity and utility. A three-dimensional surface is then developed using the model describing the SAG mill throughput capacity at varying conditions (speed-filling) versus varying blend. The change in throughput as a function of only the changing charge composition is presented. The result is nonlinear, and explanations are provided to describe this behaviour.

Aug 24, 2022

The Savage River open cut magnetite mine is located in rugged terrain in densely rain forested northwest Tasmania. The mine and concentrating plant are both in the Savage River valley. Pickand Mather Incorporated (PMI) operated Savage River as an open cut magnetite mine between 1966 and 1996. Acid rock drainage (ARD) was first noted in the last ten years of the operation, leading to elevated concentrations of heavy metals downstream of the mine. When operations ceased in 1996, PMI returned the mine to the Tasmanian Government along with a remediation fund of $11.4 million. At that time, the assessed cost of remediation was in excess of $120 million. As a result of the ongoing ARD contamination and to facilitate both a new operation and effective remediation, Goldamere Pty Ltd negotiated an agreement with the Tasmanian Government in 1996, which resulted in the Goldamere Act and the Goldamere Agreement. The agreement has allowed Australian Bulk Minerals (ABM) to remediate the Savage River mine in conjunction with the Tasmanian Government while re-invigorating a previously closed mine by providing ABM with an indemnity against past pollution. ABM can configure its mine and waste planning activities to maximise remediation benefits without fear of future litigation for past mistakes. The effect to date has been the development of a long-term strategy to remediate the Savage River and short-term remediation works such as water management, which provide benefits to the ecosystem. After five years, the Savage River is no longer significantly impacted by ARD for 30 kilometres downstream and trout are now reported within the reaches of the mining lease. The arrangements between ABM and the Tasmanian Government are an example of a genuine WIN WIN situation where co-operative environmental management of the site results in significant improvements and where the æregulatorÆ and the æminerÆ are working together to achieve mutually beneficial goals. The end result is a significant benefit to Tasmania.

Jan 1, 2003

Mechanical and electrical (M&E) systems in road tunnels are constrained by the traffic envelope and the construction profile. Whilst these spatial constraints are often ælocked inÆ early in the design process, the detailed M&E design continues for some considerable time after key civil engineering issues have been resolved. Ventilation design criteria for both normal and emergency operation often involves considerable negotiation with a wide range of stakeholders. Final system performance and spatial requirements are only finally resolved when suppliers are selected following the tender process. Lighting design is dependent upon a wide range of factors including tunnel lining materials and associated colours as well as agreed maintenance regimes. Cabling systems can only be developed when the general arrangement for power distribution is agreed and a system of substation, switchrooms and equipment rooms is in place. Many other systems such as fire protection and communications facilities fill the available space beyond the traffic envelope, where physical, structural and æsight lineÆ requirements must all be accommodated. The more co-ordinated civil engineering and M&E design is and the earlier the process starts the better the outcomes for all parties.

Jan 1, 1999

By Lloyd F, Arnold D. A, Hagan T. O

This paper investigates the problems that are encountered in mining at extreme depths. It looks into the rock mechanic aspects, especially the high stress levels that will occur, and the hazard of rockbursts. Furthermore, environmental problems are discussed, with refrigeration and reduction of neat loads being major methods of maintaining ,sorkable conditions. The paper concludes that it will be of tmost importance to have a planning team of Tne highest quality to ensure that conditions are maintained so that work can be carried out safely and under reasonable conditions.

Jan 1, 1986

By Thirnbeck M, Sione T, Petrie P, Leach TM, Mori W, Digan K, Harry K

Gold and lesser copper mineralisation are associated with porphyry-related vein systems periph-eral to two separate inferred intrusive centres north of Kainantu, Papua New Guinea (PNG). The intersection of NW trending structures, formed parallel to the Markham Fault, with NE trending transfer structures localise porphyry intrusions, and control vein distrib-ution.The Arakompa veins intrude pre-existing fractures in Akuna granodiorite, located proximal to an inferred porphyry. These veins are characterised by early quartz and later pyrite-chalcopyrite. Gold mineralis-ation is associated with Bi-Te phases in the sulphide veining. At Maniape, en echelon gash veins occur within the imbricate portion of a regional structure. Maniape is a high level carbonate-base metal gold system formed distal to the same porphyry source as Z ?-;4 kmmna

Jan 1, 1994

The Beverley uranium mine û now in production in the remote north of South Australia at1000 tonnes per annum û was established to meet a projected, but little-recognised shortfallin primary supply of uranium for the nuclear industry in the early part of the 21 st century. Inthe context of AustraliaÆs lack of bi-partisan support for uranium mining and the nuclearindustry, a four to five year window of opportunity existed from 1996 to establish the mine.During this period, Beverley achieved a number of firsts including: the first ISL mine inAustralia; the largest ISL mine in the world and the first to produce more than 500 tonnes ofuranium in its first year; the first to be established under a new Native Title regime in SouthAustralia; and the first to be established under a revised South Australian Mining Act.Beverley was brought into production against the background of: hostile opposition fromanti-nuclear activists; a suspicious and at-times hostile media; a regulatory and politicalcommunity that was unfamiliar with ISL mining; commercially unsophisticated Aboriginalgroups; an inexperienced engineering industry; and the vagaries of development in a remote,semi-arid location with neither population nor infrastructure. The lessons that can be learnedfrom Beverley showed that û like much in life û flexibility and timing are crucial.

Jan 1, 2002

By T Baumgartl, M Edraki, L Huang, D R. Mulligan

"Phytostabilisation with tolerant plant species has been advocated as a cost-effective solution for sustainable cover of tailings from metal mines and bauxite refinery. The development of sustainable plant ecosystems on such wastes requires not only tolerant plant species compatible with local climatic conditions, but also the formation of stable and functional root zones through systematic processes to develop functional soil matrix and horizons (eg A-B-C). However, the process requirements for reconstructing functional root zones in tailings are poorly understood. Based on a review of current literature and industry experience in tailings revegetation, the present paper conceptualises three key phases in the process of root zone development in amended tailings: hydro-geochemical stabilisation resulting from the interactions among tailings characteristics, amendment measures and local climatic conditions the rehabilitation of soil biological capacity the establishment of ecological (carbon and nutrient) linkages between the rehabilitated root zones and the above ground plant communities.Key research is required on: the relationship between hydro-geochemical stability and mineralogy and geochemistry of tailings, in response to rehabilitation treatments under local climatic conditions the relationship between soil biological capacity and hydro-geochemical stability in the root zone the transition of soil microbial communities specific to exogenous organic matters into those required for mineralising litters of in situ plant communities.CITATION:Huang, L, Baumgartl, T, Edraki, M and Mulligan, D R, 2012. Sustainable phytostabilisation of mine tailings - A critical analysis of system requirements and approaches, in Proceedings Life-of-Mine 2012, pp 105-116 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By L Dzinza, K C. Corin, M Tadie

The recycling of process water comes with increased electrolyte concentrations that affect water quality, which may in turn affect the flotation performance of valuable minerals (Hirajima et al, 2016). Electrolytes such as Ca2+, SO4 2- , Mg2+ and S2O3 2- have been surmised to have an impact on the action of flotation reagents such as collectors (Ikumapayi et al, 2012). Xanthate collectors are known to play a significant role in imparting hydrophobicity on mineral surfaces to enhance their flotation. The interaction between minerals and xanthates is well known to be electrochemical in nature. Such redox processes may be elucidated by electrochemical techniques. Since the mechanisms involving the interactions between electrolytes in process water with sulfide minerals and the subsequent adsorption kinetics of collectors are not well understood, this study therefore aims to provide fundamental knowledge to unpack the mechanisms involved when electrolytes interact with Platinum Group Minerals (PGMs) and how these interactions may affect xanthate adsorption. The interaction of sodium iso-butyl xanthate (SIBX) in the presence of electrolytes at increasing ionic strength was investigated by rest potential measurements, to explain the impact of electrolytes on the adsorption of SIBX on PGMs in the flotation process. Rest potential measurements for PdTe2 and PdS were conducted in an air saturated 0.05 M di-sodium tetraborate decahydrate solution, in the absence and presence of SIBX and electrolytes. It was found that the existence of sulfide and telluride on palladium affects the mechanisms in which electrolytes interact with Pd mineral surfaces. An increase in the ionic strength of Na2S2O3, CaCl2 and MgCl2, increased the interaction between the salts and PdS, thus decreasing the extent to which SIBX interacted with PdS. An increase in ionic strength for Na2S2O3 increased the interaction between Na2S2O3 and PdTe2 and therefore decreased the extent to which SIBX interacted with PdTe2. Other salts investigated in this study increased the rate of oxidation of PdTe2 with an increase in ionic strength thereby enhancing the interaction of SIBX and PdTe2. This study has shown that mineral type, electrolyte type and concentration all have an impact on the mechanisms that result in the adsorption of SIBX on PGMs.

Aug 24, 2022