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By S N. Nyoni, K C. Corin, C T. O’Connor

Considering future water scenarios, as influenced by the increasing scarcity of water and the move towards sustainable process engineering etc, the closed water circuit becomes an important point of study in metallurgical operations, such as in milling and flotation. However, a deterrent in the use of recycled process water is often a lack of understanding of the effects of the accumulation of dissolved ions and other process chemicals. Recovery of the valuable minerals may be impacted by the concomitant complex mineral-pulp chemistry interactions. Literature indicates that these interactions are not necessarily antagonistic to process outcomes. Wet milling using steel media results in the dissolution of Fe from the media, the rate of which is dependent, inter alia, on the type of media and the chemical conditions of the aqueous environment in the mill. The pulp-phase interactions of dissolved ions with sulfide minerals may result in significant changes to the chemical conditions in the mill, which may subsequently impact negatively on the flotation recoveries. To understand the effect of these interactions in the context of the processing of sulfide minerals, this study seeks to consider the effect of three factors, viz mineral type – pyrite (Py) and galena (Gn) -, milling media of different compositions – forged steel (FS), 21 per cent high chrome and ceramic media -, and water chemistry, viz, deionised water (DI) and synthetic plant water (SPW). Ceramic media and galena are used for the respective control cases where the milling media and sulfide mineral contribute no Fe species. Using DI as a control case, a high ionic strength case is used to mimic the changes in water chemistry for a closed water circuit. Batch flotation tests are used as a diagnostic tool to determine the effects of these media-water-mineral interactions to investigate correlations between the chemical reactions occurring and chemical species present during the milling process and the ultimate flotation performance.

Aug 24, 2022

By N Wharmby

In recent years in New Zealand there have been a number of tunnelling and deep directionally drilled pipelines projects that have required access shafts. Often these shafts are in urban environmentswhere vibration and high noise levels are not tolerable. There are a number of methodologies that can be adopted dependent upon the shaft plan area, depth and geology.This paper will describe some different methodologies that can be adopted that use piling methods such as large diameter piles, and secant piles. The paper will use case studies to highlight:· construction methodology,· specific methodology issues and constraints,· lessons learnt, and· recommended specifications.The development of piling technologies in New Zealand has enabled the development of cost effective solutions for the construction of deep shafts in sensitive urban environments.

Mar 8, 2011

One of the problems with mining projects is the setting of the design criteria that will best match the requirements. Normally this is expressed in economic terms but can be other factors. With massive orebodies these problems are often compounded by the general lack of distinct mining boundaries. A technique using evaluation surfaces was developed at Palabora for the underground mine design. This technique has subsequently been applied on several other mining projects to assist in the determination of the design criteria. This paper discusses the method, illustrated by some of the results of these studies.

Jan 1, 2000

By Ö Aydan

Rock dynamics is one of the most important topics in the field of rock mechanics and rock engineering. The spectrum of rock dynamics is very wide and it includes the failure of rocks, rock masses and rock engineering structures such as rock bursting, spalling, popping, collapse, toppling, sliding, blasting, non-destructive testing, geophysical explorations, science and engineering of rocks, earthquakes, and impacts. Undoubtedly, the rock dynamics issues in Mars would remain to be the same. Although mankind has no direct access to Mars yet, the Mars exploration rovers (Opportunity, Sprit, Curiosity and Perseverance), Mars Reconnaissance Orbiter and InSight Lander provided very valuable data so that some rock dynamics issues can be recognised. The author reports his considerations on rock dynamics issues in Mars from very careful examination of images and data provided from MERs and MRO and discusses their implications.

Nov 29, 2022

By G R Ryan

Recent events have raised the issue of whether, and if so when and how, an explorer may gather data from a mining tenement or permit which is held under the relevant mining Act by another party. Two situations arise: that of the small operator who wishes to prospect, and if successful mark off, ground held by others by virtue of the local form of exploration permit; and that of a regional explorer who may wish to enter on to some one else's existing mining tenement within the region of interest. The legal situation varies from state to state. At present the broad consensus seems to be that, provided consent is given, small-scale prospecting on another's exploration permit is at least tolerated if not actually provided for by the relevant Act. Entry onto a granted tenement to carry out any form of exploration is, however, prohibited in all jurisdictions unless consent is given. Furthermore it would appear that the proposal and conclusion of a joint venture agreement places certain obligations upon the party proposing to carry out exploration. These conclusions apply where ground surveys are proposed. Where data acquisition is by aerial survey the situation is much less clear, principally it would appear, because up to now little thought has been given to it. If trespass applies at ground level, at what height does it cease to apply? Can aerial magnetometry or photography be classified as prospecting? Is there an obligation upon public authorities who carry out remote sensing to make data available to the holders of mining tenements within the surveyed areas? Moves are now afoot to address these and other considerations, and it would be in the interests of everyone if a national approach to the problem could be adopted from the beginning. Certain suggestions in this respect are put forward.

Jan 1, 1994

The authors are looking at the behaviour of the mineral processing circuits by means of the simulators operating under random disturbance. The present paper deals with the fuzzy control systems in comparison with PID controllers. A series of tests are conducted on simplified prototype processes with (1) dead time plus first-order lag model and (2) diffusive model. In the next series of tests the self-sustained process model was introduced to improve control against dead time. In both cases fuzzy and PID controllers are optimised by EVOP method. Particular attention is paid to the effect of observation noise to analyse for the problems which can be fatal to practical applications in mineral processing. Finally the methods developed are applied to a closed-circuit wet grinding system simulator operating under random disturbance.

Jan 1, 1993

Hydrometallurgy has a history of over 300 years with copper leaching and cementation having been exploited in Spain as far back as 1670. Since then, hydrometallurgy has become an integral, expanding branch of extractive metallurgy. This paper reviews major developments in hydrometallurgy over the past century with emphasis on recent commercial developments and their impact on the mining and metals industries. The environment in which these developments has taken place has changed significantly in the past two decades and many factors, often non-technical, have emerged as constraints on the operation of existing plants and the expansion and development of new hydrometallurgical operations. Finally, a number of possible new developments that will shape the future of hydrometallurgy in the new millennium are discussed, particularly as they relate to the assimilation of technical advances in other areas of science and engineering. The impact of current trends in the education of hydrometallurgists and the provision of research in support of these future developments is also addressed.

Jan 1, 2000

The perception of New Zealand as an exploration destination has improved compared with other countries. There has been a realisation that New Zealand's potential is greater than previously thought. Other countries are not as attractive as before, and explorers are looking at alternatives that are geologically prospective and politically stable.   New Zealand is regarded as geologically prospective, especially for gold, with potential for world class deposits. It is also prospective for other metals, coal and industrial minerals. New Zealand is politically stable, and has an economy that is attractive to overseas investors. It is one of the least corrupt countries in the world, which overseas companies see as providing a high degree of certainty for investment.   New Zealand has good opportunities for investment in gold exploration at present. Otago has been the focus for new companies and is the favoured exploration location. Otago is regarded as very prospective, and hosts New Zealand's largest gold deposit at Macraes. There is potential for other similar deposits elsewhere in Otago.   The mineral industry previously had an excessively pessimistic view of New Zealand, which has resulted in little new investment in New Zealand for some years. Previous pessimism is turning to optimism, and there is increasing interest in New Zealand as an exploration destination by overseas explorers.

Jan 1, 1997

By W R. Adamson

"Optimisation of drill and blast design and engineering can deliver a significant positive impact on the profitability of any mining operation; however, true engineering of the blasting process is less common than might be thought. The paper that follows explores this gap and suggests a process control-based approach to the challenge.The concept of applying modifications to drill and blast designs in order to achieve efficiency improvements in downstream mining processes is far from new. However, the author suggests that the practical application has become less than rigorous in a number of different sectors of the mining industry in a wide range of countries.There is a common tendency for the design process to become simplified to the point where the objective is merely the communication of instructions to field implementers (drillers, explosive suppliers, blasters, etc). In effect ‘design’ often degrades to ‘cut and paste’ with consequences that vary from mild to critical, with respect to the profitability of the business.Engineering of the drill and blast process involves the design function, not on a one-off basis but rather as a component of a more complete cyclical process that includes a statement of objectives, a design based on a suggested hypothesis, field measurement of results, comparison with the target ‘set point’ and the application of control measures followed by new measurement, including interpretation of the results in financial terms.When applied in this fashion, engineering provides practitioners with the means to optimise the drill and blast impact on the full spectrum business result of the mining activity.These concepts are discussed with reference to a surface gold mining operation applying run-of-mine heap leach extraction. Engineering optimisation by adapting process control and measurement techniques is demonstrated to be a key component of the solution set applied to generate enhanced operations productivity and stakeholder value. It is shown that a combination of rigorous measurement, model calibration and hands-on quality assurance/quality control facilitates the creation of a road map to profitability, stressing the need to consider economic trade-offs between operational expense (investment) and measurement of enhanced value (return on investment).The process, however, does not cease at this point. Implementation of true design practices, incorporating innovation and discipline in implementation or execution can drive the process to deliver demonstrable, technically validated outcomes. Furthermore, these technical results can be related to financially quantifiable impacts. However, this accomplishment does not guarantee that these gains or savings will reach the bottom line of those mining, quarrying and construction companies that begin the process with such high hopes.CITATION:Adamson, W R, 2015. Application of engineering discipline and a full-process optimisation focus – productivity to profitability without profuse pruning, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 3–12 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 24, 2015

By Dr Subagyo

The energy consumption for producing metal from ore is strongly linked to the chemical stability of mineral being processed, availability and richness of the ore, and process route. Energy efficiencies are particularly linked to the process route. The energy efficiency of high temperature operations vary considerably but energy efficiencies greater than 70 per cent are achieved for large-scale metal production. Low temperature processing through grinding, leaching and subsequent electrowinning use large amounts of energy. In particular, grinding and electrowinning suffer from low overall energy efficiencies. The physical chemistry of a new proposed low temperature route, reactive ball milling, is unclear but preliminary evaluations indicate that it is likely to suffer from high energy consumption. In conclusion, low temperature processing routes for metals generally consume more energy that comparable high temperature processing routes.

Jan 1, 2002

Prior to the merger of BHP and Billiton, both companies had a keenfocus on improving their performance in health, safety, environment and community (HSEC) matters. This shared intent, albeit executed insomewhat different ways, provided an excellent foundation for the newCompany. During the integration planning phase, a team was formed toconsider the organisational design for consistently achieving world class HSEC performance. The design included the policy platform, resources, structures, standards and procedures to be implemented in the merged entity. A key aspect of the design was the fully integrated HSECManagement Standards. These Standards create the framework for theconsistent application of BHP BillitonÆs HSEC Policy at all of ourmanaged operations across the world. The Standards have their origin in similar frameworks adopted by BHP during the 1990s, as well as thewell-known quality related standards (eg ISO 14001). However, they areunique in that they combine all aspects of HSEC management into asingle integrated set of auditable standards. By combining these areas and integrating our HSEC Management Standards with other aspects of the æBHP Billiton WayÆ, we are establishing a holistic, line management driven improvement approach. Over time, the BHP Billiton Way will embed a systematic improvement philosophy that we expect will become a key source of competitive advantage. The HSEC Management Standards are consistent with ISO 14001,OHSAS 18001, the Australian Minerals Industry Code for EnvironmentalManagement and generally aligned with SA8000. While compliance withthese external standards ensures that a systematic approach andimprovement plans are in place, BHP BillitonÆs HSEC Standards gofurther to include minimum performance requirements that reflect theintent of our HSEC Policy. Therefore, implementation at site levelensures that robust systems are in place to implement our Policy and that accreditation can be achieved to external standards if required.To assess implementation of the HSEC Management Standards anaudit system has been designed which incorporates both self-assessmentand peer review. Each site is required to undertake an annualself-assessment of compliance with the Standards using a commonassessment protocol. Every three years a peer review is conducted at each site to confirm the results of self-assessment and to provide a means of sharing knowledge throughout the Company. The review teams are composed of line managers and HSEC professionals from around theCompany, representatives of our joint venture partners and independentspecialists as required. The Company has committed to public reportingof the audit results through our annual HSEC report and this is reflected in our published targets. From a wider perspective, as we in the resources industry strive tocollectively raise our HSEC performance and reputation, there may be arole for industry based HSEC Management Standards complemented bya level of independent review.

Jan 1, 2002

By N LaBranche

The resurgence of Silicosis and Coal Worker’s Pneumoconiosis (CWP) in coalmines has placed the spotlight back on the management of worker exposure to particulate matter across all mining sectors (Coal Workers Pneumoconiosis Select Committee, 2017). There already exists a substantial body of knowledge on particulate matter and its impacts upon human health (National Academies of Sciences, Engineering and Medicine, 2018). The contribution of silica to respiratory disease is well known. However, it is also clear that there are major gaps in our understanding. In part, those gaps relate to the contribution to adverse health effects of mineralogical constituents in the dust (LaBranche et al, 2021a). It is also becoming evident that the size and shape of the particulate matter can affect its potential impact on human health. The University of Queensland has developed a methodology for characterising respirable and inhalable dust samples using scanning electron microscopy. Multiple samples from numerous mining operations have already been analysed using the UQ methodology. The process has been successful in showing the variety of mineralogical components and particle size distributions present in various areas of the mines.

May 5, 2022

Jan 1, 2004

Independent assessments of existing and projected mining operations are often required in the exchange of assets and for raising capital, requirements which are particularly prevalent where there are new mining fields, a characteristic of the Pacific Rim area. Such audits and appraisals typically consist of a geological evaluation of the ore deposits; estimates of mineral inventories and mineable reserves; assessment of mine plans and costs; assessment of ore processing methods, recoveries, and costs; assessment of infrastructure and G&A (general and administrative) requirements and costs; assessment of environmental, permitting and reclamation requirements and costs; and, finally, economic evaluation based on various discount rates and metal prices. Audits provide a challenging task for consulting engineering companies, but one well worth the effort for mine developers and those connected with financing of the mining industry.

Jan 1, 1990

The basic principles of mineral valuation were recognised and propounded at the beginning of this century and have remained virtually unchanged since then. Valuation is seen as a two part process commencing with a technical examination of the mineral property followed by a manipulation of the results of the technical examination in order to determine the monetary value of the project. A thorough and competent technical examination was seen then and remains now as the essential but not sufficient foundation for reliable valuation. All authors stressed the need to maintain the integrity of the data base and to ensure adequate coverage of all relevant aspects. The monetary valuation process through most of the first half of this century was mainly based on the Hoskold two rate method, derived from the formulae for valuing annuities but modified to provide explicitly for recovery of capital. Though the basic principles of valuation have not changed significantly, the means of implementing the components of the technical examination, the styles of deposits being evaluated and the mechanisms of monetary valuation have changed dramatically. Despite all the technological improvements, however, mineral

Jan 1, 1995

Surface geological observations are predominantly two-dimensional but can be expanded into three dimensions using geophysical techniques. These techniques have proved succ- essful in the past and will be utilised more frequently in future mineral exploration. Geophysical training establishments must recog- nize future requirements and teach geophysics as part of a broad earth science course as well as a specialised geophysical course. Central- isation of teaching skills, the use of high- technology in the classroom, and greater interaction between academic and industry staff are recommended as a means of ensuring a vibrant geophysical training base in Australia, for the geophysicist of the future.

Jan 1, 1986

There has been a significant increase in exploration and development of mineral wealth in South East Asia over the past five years. This paper describes the foreign investment laws in the region as they relate to the mining industry.

Jan 1, 1993

The Elgas Underground Storage Facility at Port Botany, Sydney, is the first purpose-built cavern of its kind in Australia and provides large capacity, safe and environmentally benign storage of Liquefied Petroleum Gas (LPG). The facility will provide Elgas with the flexibility to source product at competitive prices and ensure long-term security of supply. Construction has provided Orica Australia, formerly ICI Explosives, with a unique opportunity to provide a bulk explosive delivery system specifically designed to meet the exacting demands of the site and of the project.

Jan 1, 1999

The use of econometric models to assess the effects of a Government's policy on an industry is gaining momentum. This is particularly so for the Mineral Industry and it is important that mineral industry management understands the techniques involved in developing econometric models. Models are usually constructed outside the industry by either government departments or their consultants and used by the policy makers to investigate artificially the implementation and ramifications of new policies. This paper discusses the application of econometric models in Governmental policy determination, highlights the use of various models in Australia and gives an overview of the techniques involved using Australian examples.

Jan 1, 1982

The space probe Magellan is on its way to Venus (May, 1989) and with its sophisticated radar systems will discover much more about our twin planet. There is tennuous evidence that Venus once had liquid water. Did it have life? Why was it not stable and why did liquid water not persist through the period of the dimmer young Sun? These are profound questions for us. We understand why Mars froze when volcanism terminated (Just as Earth will freeze one day) but could Earth boil if we continue to add greenhouse gases (Broecker, 1985). What will happen if 10 billion humans continue to use fossil carbon as their main fuel source? The Earth is warming fast and the new satellite data show that the oceans are warming faster than we thought. Is this just a fluctuation or is the greenhouse signal coming through the normal noise of climate?

Jan 1, 1990