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By Marton A

The Readymix Group have a Quarry Improvement Program - 'Building in Quality (BIQ) which has many parallels to the ICI Explosives' total quality management - 'Quality Improvement Program' (QIP). Both companies have for some time recognised that the 'do it right first time' principle means less wasted effort and materials, that efficiency breeds profitability and so actively promote the quality culture. To install the principles and generate the culture requires considerable commitment and effort from the top down and invariably spreads to the suppliers and sub-contractors. Understanding the component processes involved with the quarry operation, analysis of those processes and gaining a breakdown of the cost of non conformance then allows the astute quarry operator to make the necessary changes to improve the process to realise profits. This paper outlines the steps in such a process and the profitable outcomes of the commitment to continuous improvement at the Nickol Bay Quarry.

Jan 1, 1994

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 Gottlieb P, Sutherland D, Jackson R

The QEM'SEM system for automated image analysis of mineral samples is described. Details of the equipment are given together with information on the methods of measurement. Finally some practical applications are described where QEM*SEM has been used for the solution of metallurgical Problems.

Jan 1, 1989

By Andrews B. S

The sinter plant at the Sulphide Corporation's Cockle Creek works produces a feed for the company's Imperial Smelting Furnace. The feed contains lead and zinc oxides and all the fluxes necessary for furnace operation. The quality of this feed is a major factor in furnace performance and the considerable flexibility of operation possible at the sinter plant has been used in efforts to achieve optimum operating conditions.Operating data is processed daily and information gathered from this source has led to three of the four improvements described.These improvements have resulted from elimination of gas recirculation, reduction of sinter returns sizing and alteration of ignition conditions and main layer fuel loading.

Jan 1, 1964

By M Khanal, J Qin, B Shen, Y Duan, X Luo

Gaining confidence in interpreting rock and strata properties of the coalmine roof is necessary for design, maintenance, modelling and optimisation of roadways supports. One of the key causes of roadway instabilities experienced in underground coalmines is an extreme variable nature (thickness, competence, discontinuities etc) of the coalmine roof. Normally, the thickness and strength of the roof are characterised with the geotechnical and geological data gathered from exploration boreholes, which are drilled often at considerable distances apart. This limited data cannot capture localised geological variations in the coalmine roof. With this background, this paper explores feasibility of using measurement while drilling concept to perform geotechnical characterisation of the coalmine roof. The parameters, for example, penetration rate, rotary speed, torque, sound, vibration, obtained during the drilling process can provide valuable insights into geotechnical properties. The paper describes the progress of the experimental work conducted at the laboratory on synthesized concrete samples representing various rock strata using a field-scale drilling machine. The samples with and without interfaces have been tested to replicate various underground roof strata. The signals returned from the drill machine, as the drill bit passes through the layers, have been analysed and interpreted to characterise whether the drill response data can differentiate various strengths associated with the rock layers. The initial laboratory results are promising as they show distinct responses of the various sample blocks in a controlled environment. The drilling data can differentiate the synthesized rock samples and detect ‘signatures’ of the roof strength variability and delineation of lithological interfaces (transitions). The weight and torque on the bit vary and show dependency on the strength of the blocks.

Nov 29, 2022

By C Gormley, G Lane, J Kwak, A Hopkins

Complex processing plants present a myriad of safety issues to the design engineer. The extent to which the design engineer manages to lay the foundations for a safe plant ultimately sets the stage for life long safety performance. Industry traditionally measures engineering safety performance by indicators such as Lost Time Injuries, Restricted Work Case Injuries, Overall Incident Frequency Rates, etc. While these measures are useful indicators of performance for the construction, commissioning and operations phase of a project, they do not necessarily drive the most appropriate behaviours for Safe Plant Design. Achieving an inherently safe design requires a diligent focus on low frequency, high consequence events. First and foremost the engineering team needs to have a design culture and methodology which leads to a plant which is as close as possible to being inherently safe. Such a culture might come from an organisation that has æmindfulnessÆ about safety, and which is nurturing a culture where warning signs are recognised and addressed. This paper explores the development of mindfulness and warning signs in design.

Jan 1, 2004

By North R. A

The Queensland Mining Act 1968-1972 has now been in force for almost two years. The Act was completely re-written and has made for easier working, e.g., there is no distinction now between Gold Mining Leases and other Mining Leases. For the first time in the history of Queensland, provision has been made for caveats, so that options etc. can be protected. The chief problem which has arisen so far has been the question of the Government issuing mining leases to the holder of an Authority to Prospect over areas which are included iri its Authority. Litigation has taken place and an Appeal, it is understood, will shortly be heard by the Privy Council. The provisions dealing with labour conditions have been brought up-to-date and generally speaking, they are quite clear as to the responsibility of the Lessee. The Mining on Private Land Act has been repealed and the provisions relating to mining on private land are now a part of the Mining Act itself. Previously, the holder of a- mining freehold did not have to pay royalty on

Jan 1, 1974

By Williams DJ, Battino S

The rapid crushing technique for the measurement of gas content of coal consists of accelerating the rate of gas desorption from coal by crushing. This technique allows the determination of gas content in the space of hours rather than days or weeks as required for the traditional slow desorption technique. The crushing technique is used particularly when gas content determinations are urgently required for mine safety purposes. The method is now routinely used in underground coal mines of NSW and to a lesser extent in QLD. Despite the rapidity and efficiency of this method, concerns have been raised upon the reliability of the method to deliver accurate results. Experience in Australia has shown that there is in fact some discrepancy in results between gas laboratories using the rapid crush technique. The development of rapid crushing techniques for seam gas content measurements in Australia and the main causes of variability in the gas content test results were investigated. The gas laboratories participating in the gas content testing were CSIRO Division of Coal and Energy, BHP Technical Services and GeoGas Pty. Ltd.

Jan 1, 1998

FIRST TOWN PLANNING PROPOSALS Initially, accommodation at the minesite was provided at the Pastoral Homestead situated some seven kilometres north-east of the mine and between 1963 and 1966 was the base of the exploration camp. Tents were used for sleeping of 100 men and the Homestead used for dining and office facilities. With the beginning of ore production and shipment due to commence in 1969 a permanent town location was sought. Early town planning studies had been commissioned by Amax Inc. and Colonial Sugar Refining Co. Ltd. and in 1967 The Broken Hill Proprietary Company Ltd. took over the responsibility for putting them into effect. The location chosen was about four kilometres due east of the mine. Certain dominant factors influenced this choice. It was near enough to the mine to share services, yet far enough away not to be affected by dust and noise and received the additional shelter of a range of hills separating it from the mine. A predominant slope to the east provided good drainage and the ground was easy to excavate for services.

Jan 1, 1976

By K C. Corin, N Ndamase, M Tadie

Mining operations in arid regions are compelled to reduce their consumption of fresh water. Closed water circuits are an attractive solution and, in addition to reducing freshwater consumption, have the added benefit of reducing reagent consumption as well as the environmental impact by eliminating effluent discharge. Accumulating ionic species have been shown to hinder collector adsorption which reduces the recovery of valuable minerals. Numerous studies have investigated the effect of degrading water quality on collector adsorption however there is very limited understanding as to how this takes place from an electrochemical perspective. This study therefore aims to investigate how the presence of accumulating ionic species at varying concentrations affects the electrochemical adsorption of sodium ethyl xanthate onto galena. The synthetic plant water used in this study comprised of single salt solutions to isolate the effects of the ionic species of interest. The ionic strengths were varied between 0.0242 M, 0.0727 M, 0.1212 M and 0.2426 M which correspond to University of Cape Town (UCT) Centre for Minerals Research (CMR) synthetic plant waters of 1, 3, 5 and 10SPW, respectively. Mineral rest potentials indicated how changing water quality affected xanthate-mineral interactions. Microflotation observed the impact of changing water quality on mineral floatability.

Aug 24, 2022

Upgrading of MgO in Dolomite Ore by Froth Flotation

Sep 13, 2010

By B Indraratna, A Dey

The surface geometry of a rock bolt plays a very important role in the rock/resin/bolt load transfer mechanism. Very little work has so far been reported on the influence of the bolt surface geometry on the bolt/resin interface failure mechanism. This paper examines the behaviour of bolt surface roughness under constant normal stiffness condition in the laboratory. To study the shear behaviour of the bolt/resin interface a series of shear tests with an initial normal stress between 0.1 to 7.5 MPa has been conducted on the flattened bolt surface of two most popular bolt types currently being used in Australia. Bolts with deeper ribs offered better shear resistance at low initial normal stress conditions whereas bolts with shallow and closer ribs offered better shear resistance at high normal stress conditions. The maximum dilation occurred at a shear displacement of 60 per cent of the rib spacing irrespective of the bolt type and depth of the rib.

Jan 1, 2000

By S A. Ravishankar

An overview of flotation reagents used in sulfide and non-sulfide separations, from an industrial perspective, is given in this presentation to highlight the current applications knowledge. The historical and theoretical aspects, which are well documented in numerous books and reviews, will only be highlighted, when necessary, to support the theme of this paper, viz critical analysis of reagent research, design, selection and optimisation with an emphasis on relevance to plant needs and practice. The three types of flotation reagents; viz collectors, frothers and modifiers, used currently in the industry are briefly reviewed; pitfalls and gaps, arising from somewhat arbitrary and reductionistic practice in reagent applications, are identified; and the impact of environmental regulations on current and future reagent development is discussed. The importance of frothers and modifiers, which have received less overall attention than collectors, is highlighted. The need for a rational, holistic (or ætotal systemÆ, ætop-downÆ) approach for reagent design, selection and optimisation is discussed with a view to provide remedies for pitfalls and a platform for filling gaps in reagent chemistry and applications, and to develop reagent technology that can deliver robust solutions to plant needs. Flotation Matrix 100TM, a comprehensive package designed at Cytec to incorporate all the elements of the holistic approach û viz definition of mineralogy and plant needs, rule-based expert system rational reagent selection, and laboratory and plant best practices û will also be described.No paper available for this abstract

Jan 1, 2005

By N Trabelsi, D Bakun-Mazor, Y Ben-Ari

As part of a comprehensive project to develop a remote sensing tool for evaluating the mechanical properties of rocks, one must obtain a rapid indication of these properties using conventional field methods. A common method for evaluating the mechanical properties of rocks in the field is to use a Schmidt hammer, a portable device that measures the rebound (R) of a spring-loaded mass impacting against the rock surface. Since the 1960s many studies have been made to find empirical correlations between the R value measured by the Schmidt hammer and mechanical and physical properties such as uniaxial compressive strength (UCS), elastic modulus, density, and porosity. Despite the existing correlations in the literature, this work is required to establish detailed empirical relationships for the carbonate rock units in Israel. To do so, 150 rock samples were collected from 38 different outcrops of carbonate rock units. In each outcrop, 20 impacts were made using a Schmidt hammer at different but adjacent points. The impacts were done horizontally perpendicular to the vertical rock walls. In the laboratory, we measured the density, effective porosity, water absorption, UCS, and elastic modulus. The rock samples we selected contained a wide range of UCS: from 7 to 270 MPa. Our empirical correlations indicate an exponential relationship between R and UCS and the elastic modulus, and linear relationships between R and density, porosity, and water absorbance. The most reliable index is the average of the five maximum impacts out of the 20 made in each rock outcrop. The correlation equations obtained from this work will make it possible to effectively evaluate the mechanical properties of the intact rock in the field, thereby aiding development of advanced tools for rock mass characterisation by means of remote sensing.

Nov 29, 2022

By Canning RL, Pritchard J

The surface treatment works in the Mount Isa Mines Limited copper stream consist of a concentrator and smelter with annual capacities of 5.6 million tonnes of ore and production of 155 000 tonnes of anode copper respectively. Both plants have been sites for process optimisation in recent years, the emphasis being to achieve productivity gains in each particular plant. The continued low real world prices for copper resulted in an in-depth review of the entire copper process stream. This indicated the need for developments within both the concentrator and smelter, and changes to operating strategy to ensure that the entire treatment stream could be optimised. The paper reviews these changes.

Jan 1, 1986

Longwalling has reached a high standard both in Germany and Australia and most improvements should be expected in planning, monitoring and control. Double drum shearer have electric drives to 1000 kW and automatic height control is under development. Conveyor pans to 40mm thickness and chains to 2300 kN breaking load are in use with controls for pretension and load compensation under test.Trends in support are towards two leg shields with loads to 3850 kN per leg and electrohydraulic controls. Expert systems have been devised for planning and diagnosis tasks. With increases in technical standards, staff qualification standards at rising too, drawing attention to training requirements for modem personnel.

Jan 1, 1991

By Williams P. A

Tailings dams constructed by the upstream method have traditionally been built using the sand fraction of the tailings, which has automatically provided a relatively permeable embankment material, and helped provide the necessary drainage conditions which are a pre-requisite for safe and stable dam construction using this method. This paper discusses some recent trends which have resulted in proposals to use impermeable material in place of the sand fraction as the embankment material, both for the starter dam, and subsequent lifts. The consequences of these types of decisions on the overall stability of the dam are illustrated, and the need for continued monitoring of pore pressures in the tailings as the dam is raised is emphasised.

Jan 1, 1992

By Y K. Leong

Iron ore tailings typically containing 40 to 50 per cent Fe can be beneficiated to iron ore products containing 54 to 60 per cent Fe. The impurities are comprised of clay, quartz, cristabolite and TiO2. Goethite and hematite are also present. At high concentrations of 55–60 wt% solids, the tailings displayed high yield stress and viscosity and cannot be pumped over long distances. Composite additives comprising of NaOH, phosphate-based additives and sodium metasilicate are found to reduce the viscosity and yield stress very significantly by a few orders of magnitude. The yield stress of 100 Pa can be reduced to almost zero. At this state, dilution of the tailings with its process water to 40 per cent solids causes the coarse and high-density iron ore particles to separate from the colloidal fractions located in the supernatant after a few minutes of sedimentation. Separation by decantation produces a sediment with an Fe content of 54 per cent from tailings with 47 per cent Fe. Another tailings sample with 48 per cent Fe was beneficiated to greater than 57 per cent Fe using NaOH-metasilicate-polyphosphate additives and employing an additional washing step. The use of other composite additives, NaOH and polyphosphates, increased beneficiated product Fe content to greater than 60 per cent from the same tailings. With the current iron ore spot price of more than US$180 per tonne, the cost of this treatment process even including a desalination step, if necessary, is relatively insignificant. This study has given tailings an economic value that should be exploited as soon as possible.

Nov 8, 2021

Although giant strides have been made in the Australian mineral industry over the past quarter of a century in terms of mineral discoveries, self-sufficiency of commodities, contributions to exports and other aspects, there are unhealthy signs emerging which require attention. For instance there are 20 out of 34 discoveries of base metals, uranium and nickel which for a number of reasons await development. Some of the reasons for the standstill in the mineral industry are partly economic, partly due to competing land use, uncertainty in applying or, recognising the principle of crown ownership of minerals, and to some extent lack of appreciation of two closely related exploration activities referred to as development exploration and assessment Exploration.

Jan 1, 1979

Hindustan Zinc Limited has successfully installed an In-Stream Analysis and Process Control System in the flotation section of the Balaria Lead-Zinc concentrator at Zawar Mines. The system comprises In-Stream Analysis to continuously monitor lead and zinc levels in feed, concentrates and tailings streams, field instrumentation for reagent distribution and flotation cell level control linked to a central Distributed Control System for supervisory control functions. An intensive training scheme was conducted by the system supplier for concentrator metallurgical and instrumentation engineers. Since commissioning of the system in April 1989, Hindustan Zinc has enjoyed the benefits of improved lead, zinc and silver recoveries, improved concentrate grade control and reduced reagent costs.

Jan 1, 1991