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The different stages of the metallurgical evaluation of an ore resource and their importance to overall project evaluation are described. Particular emphasis is placed on the liaison that is necessary between the different members of the project team from the preliminary exploration phase through to the completion of the final feasibility study. Metallurgical input at the earliest stage is recommended. The incorporation of metallurgical and marketing data into ore reserve statements and the effect of the metallurgical evaluation on ore reserve classifications are discussed.

Jan 1, 1987

By Braes J. R, Neale J. R

The New Broken Hill Consolidated Limited (NBHC) mine currently produces 1.42 million tonnes of silver, lead and zinc ore annually. All of this ore is treated by the NBHC milling ccx[plex. This paper describes the crushing, grinding, flotation and filtration circuits used in the treatment of this ore and lists the major items of equignent used in these circuits. Metallurgical results, manning levels and consumption rates of reagents and grinding media are shown.

Jan 1, 1983

Economies in cemented fill demand the utilisation of the full potential of the portland cement component of the mix. If declined tailings are used, it is desirable to establish the optimum particle size distribution. Pozzolic materials and slags are. very useful additions to increase the amount of cementitious material through reaction with calcium hydroxide produced by hydration of the cement. It is also essential to check out the presence of substances which may seriously affect the setting and hardening of the cement or the durability of the cement bond. The importance of quality control in the preparation of cemented fill cannot be over Emphasised.

Jan 1, 1973

The causes and impact of stability problems associated with longhole open stoping (LHOS) at The Zinc Corporation, Limited (ZC) and New Broken Hill Consolidated Limited (NBHC) are discussed and LHOS stability objectives presented. The development of appropriate rock mechanics techniques is discussed and the reasons for using contract research are explained. Reference is made to the rock mechanics techniques developed and in use. The requirements to effectively use these techniques are discussed. Features of the staffing policy which has been adopted to develop and apply the LHOS stability assessment and control techniques are Outlined.

Jan 1, 1983

This paper looks at the problems associated with surface settlements and other subsidence effects from the underground extraction of coal in relation to consent applications under the Resource Management Act. The main features of subsidence are examined with respect to identifying the adverse effects as defined under the RMA. Particular attention is paid to sites where little or no data is available as in the case of greenfield sites or at mines where new or different mining methods are being introduced. In these situations it is not possible to make accurate predictions of settlements or strains and therefore other factors need to be considered. The long term effects which might occur post mining are examined in relation to mitigation and management options.

Jan 1, 2003

Many aspects of best practice resource evaluation do not create value, but poor practice can certainly destroy value. Generally companies prefer to present how their good practice adds value and for this reason few publications exist on examples of how poor practice can destroy value. However in big and small companies there are many previous and current examples of poor practice destroying value. The incremental expenditure required to move from poor practice towards best practice can be looked upon as insurance against destroying shareholder value. Examples of how poor practice in geology has destroyed value are presented as well as the improvement model used by BHP Billiton to add value and insure against destroying value.

Jan 1, 2002

In the past five years, there has been an evolution in the assessment and control of mining risks in the New South Wales coal mining industry. This change has involved the development and use of structured, systematic, team-based risk assessment exercises to identify, assess and control unacceptable risks to people, equipment and production. The outcomes have improved the management systems in the mine. This paper discusses the evolution of the risk assessment approach in equipment design and mine operations, as well as the specific risk assessment methodology. The paper also presents the reactive side of risk management, the method of investigating failures in the management system, usually referred to as incidents or accidents.

Jan 1, 1994

For various reasons, the maintenance of shaft structures is becoming an increasingly important factor in the operation of underground mines. Deterioration mechanisms related to operation of the shaft are identified as corrosion, mechanical damage, fatigue damage and wear. Deterioration mechanisms related to rock movements are identified as vertical strain, ride vertical closure and squeezing. Analytical procedures for assessing this deterioration are discussed, and it is shown how acceptance criteria are developed and implemented. In order to track the deterioration of shaft structures, shaft inspections are undertaken, but the information is often not well documented. Formalised procedures for capturing and recording information, and then processing the information are presented. Finally, two case studies are briefly described to illustrate how these procedures have been implemented in practice, and what benefit has accrued to the mines concerned.

Jan 1, 2005

By Pirvics AI, Whitworth NR, Tuppurainen JMI

Process control applications to the unit operations in both the Lead and Copper Smelters are reviewed. The basic aim of this control is to smooth plant inputs to produce an output of consistent quality in terms of chemical composition, temperature and physical properties. Most effort has been put into the process bottlenecks, namely in the process baghouse of the Lead Smelter and in the Copper Smelter reverberatory furnaces. The method of approach is discussed, firstly extensive plant measurement and data logging plus identification of factors which most affect the unit operation and secondly control of these factors to smooth out variations. This has been possible due to the development in-house of on-line instruments to measure the critical variables and the external use of computers for plant control. Some of these instrument developments are also briefly discussed.

Jan 1, 1984

Mount Isa mine is the largest underground mine in Australia and is located 2,000 kilometres north-west of Brisbane. This mine has been in continuous operation since 1931 and in 1986/87 the silver/lead/zinc stream achieved the peak annual mining rate of 4.7 million tonnes. At present about fifteen different steeply dipping stratiform orebodies are being mined to maintain an annual production rate of around 3.0 million tonnes. Out of these, only two orebodies (2 & 5) are amenable to sub level open stoping (SLOS) type bulk mining methods. This year only 150,000 tonnes are scheduled from pillars and remnant areas but in future, more sources will be required to meet the budget production targets.

Jan 1, 1990

The article presents methods of testing and recording of water amount pumped out in surface mining. The authors describe necessary recommendations how to carry out measurements so that one can separate the surface run-off and groundwater inflow from the total inflow. They demonstrate methods of evaluation of these kinds of inflow in open pits when water amount testing is carried out every eight and 24 hours as well as simple methods when only monthly records of water are available. The authors also describe procedures for evaluating the water inflow when an open pit is dewatered gravitationally and measurements in discharge channels are irregularly carried out.

Jan 1, 2003

By Moorrees C

The end uses of magnesia are determined by both its chemical and its physical proper- ties. There is seen to be an increasing need for products of high chemical purity. Prod- ucts containing 90-95 per cent MgO can be routinely produced by physical beneficiation and calcination of most magnesite ores, the dominant source of magnesia. However, pro- duction of grades containing more than 98 per cent MgO with low impurity levels is not readily achieved physically. Such products can only be readily produced by chemical processing techniques. This presentation outlines the types of impurities present in magnesite deposits and the general concepts that are involved in chemically upgrading them. Of the potential leachants, only hydrochloric acid and aqueous carbon dioxide appear to be commercially attractive.

Jan 1, 1987

By W Angerer

This paper describes the design of the marine riser structures, including the design measures for sealing and protection from flooding, dewatering and connection to the main tunnels, for the Gold Coast desalination plant in Queensland. The risers connect the intake and discharge tunnels to the ocean. Construction commenced on both in April 2007. The paper describes the key design criteria for the risers, the construction constraints that influenced the design and the design of the main elements of the risers and the connections to the tunnels.

Jan 1, 2008

Increasing attention is being focussed worldwide on the strategic environmental assessment of mining projects, including consideration of cumulative environmental effects. In New Zealand there is now an end in sight for inappropriate delays in resource consent approval of responsible mining projects. This paper investigates six case examples of recently consented mining and quarrying projects, whose applications were notified. It also explores the nature of delays that occurred, the factors that contributed to the delays, and whether the consent process delivered fair and effective public participation and desirable environmental outcomes.

Jan 1, 2005

By W Dodson

Major ions, d18O and d2H and Carbon-13 concentrations in groundwater from 30 bores near an open pit iron ore mine were used to better understand the chemical evolution of groundwater in the aquifer. The relatively depleted d18O and d2H isotopes of groundwater from various depths suggest that groundwater is recharged from intense rainfall events, with little evaporative effect. The 300 to 500 mg/L increase of major ions relative to that of rainfall is due to evapotranspiration of rainfall during recharge. Geochemical mass balance modelling suggests that the evapotranspiration of rainfall during infiltration through the unsaturated zone varies over six fold from 20 to 130. This coupled with the dissolution of CO2 from the unsaturated zone and partial dissolution of carbonates and gypsum from Tertiary sediments and carbonates from the Wittenoom Formation accounts for the current major ion, d18O and d2H distribution in groundwater. Despite the relatively dissected morphology and steep hydraulic gradient the results of this study highlight the dominance of vertical flow relative to horizontal flow. The study also shows the dominance of rapid recharge by significant rainfall events as an important component of the water budget for east Pilbara aquifers.

Jan 1, 2009

At CPA we believe that ore bodies discovered in future will be bigger and higher grade than the ones currently known and set out targets accordingly. Discoveries over the last three decades substantiated this approach.

Jan 1, 1987

By Mukherjee R, Bandopadhyay S

Three applications of fuzzy logic in mineral exploration show the possibility of providing feasible solution and allow greater freedom in decision-making processes for geoexploration data which may be ill- defined, biased or where apriori infor

Jan 1, 1998

The seemingly insatiable world demand for mineral and energy products is continuously pushing out the frontiers of exploration and development in countries around the Pacific Rim.

Jan 1, 1990

Installation of spirals as roughers and scavengers in the gravity and regrind recovery circuits has allowed rejection of large weight fractions to tailings, thus contributing to increased mill capacity.

Jan 1, 1978

I will confine my remarks to normal computers that people interact with, rather than built-in processors which exist in every watch and washing machine these days. I will also confine myself to computing in the technical side of mining. Bu

Jan 1, 1998