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By J Fisher, M Castro, A Hariyadi

The train haulage system being designed for PT Freeport Indonesia’s Grasberg Block Cave (GBC) will be located within the mine at an elevation of almost 3000 m above sea level on the west side of the island of Papua, Indonesia. The developing block cave is beneath the active Grasberg Open Pit and will transport 160 000 t of ore per day from multiple chute galleries to the underground crushing plants. The design entails 28 km of rail and 119 ore chutes, which will be brought online over the course of ten years.The train haulage system will be driverless and fully automated. Sequentially, the system includes remote controlled rock breakers at the top of the chute grizzlies, followed by remote controlled chute loading of the trains, then autonomous train haulage and autonomous unloading. An overhead catenary system (OCS) will power the locomotives, which are equipped with on-board batteries to drive through the loading and unloading sections. Service locomotives with drivers move material-laden freight cars in and out of the service shaft, destined for workshops, the magazine and batch plants. Service locomotives are also used for haulage level maintenance. Highly reliable and redundant control and communications systems are required to manage 12 trains in simultaneous operation.This paper provides an overview of the train haulage system’s technical complexities and the associated support systems interactions. The paper also highlights the project management issues and successes of this globally sourced project.CITATION:Hariyadi, A, Castro, M and Fisher, J, 2016. Automated train ore transport, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 563–570 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Mining companies in order to compete and succeed in being viable business propositions must look to the future and select mining methods which guarantee improved efficiency and productivity as well as lower costs. A mining company in adopting a method of mining must now select the equipment most compatible. To some mines compatible equipment may mean the use of drilling jumbos to replace hand held rock drills or the use of load haul dump units to replace scrapers. To other more mechanised mines compatible equipment may mean the use of raise borers and road heading machines. The right decision will be where equipment compliments method in such a way that the working environment is improved, productivity is maximised, cost if reduced and all profit opportunities are optimised. An example of such is where the use of improved mining techniques in underground operations may see cut off grades reduced. By selectively mining these lower grade orebodies, smaller operation's ore reserves improve and the capacity for continued growth is enhanced.

Jan 1, 1990

Tunnels are being built around the world using TBMs and prefabricated segments or in situ concrete as linings. Clients demand high quality of these linings to guarantee a long-term stability and density of the tunnels. This paper describes the development and the use of segmental lining systems, including joints, important design criteria, installation procedures, possible mistakes and consequences, repair works and final results for different sites in Europe and around the world. The experience on these sites shows that damages may occur, if some essential aspects are not considered. These aspects include:parameters of the TBMs and back-up equipment such as fixation of jacking rams, movement of the back-up on the lining or ring reformer;parameters of the segments such as quality of moulds, quantity of reinforcement or structure of the joints; andparameters of the tunnel drive such as advance rate, ring-gap grouting or experience of the tunnel crew.All these aspects have to be considered very carefully in detail to get a good lining accepted in total.

Jan 1, 1999

By G B. Arehart, J L. Mauk

Quartz veins from the Martha Hill epithermal gold-silver deposit, Waihi, commonly exhibit crustiform banded textures. Visual differences observed between bands are primarily the result of a 1 to 1500 ¦m variation in quartz grain size. Quartz band textures are dominated by anhedral interlocking quartz mosaics, commonly associated with minor adularia and sulphide phases; these textures are interpreted to be products of amorphous silica crystallisation. The occurrence of rhombic adularia suggests that prolonged boiling influenced parent fluids. In contrast, the presence of coarsely crystalline bands, made up of subhedral to euhedral quartz grains, infers primary crystal growth from solution; evidenced by the occurrence of growth-zoned quartz within these bands. There is a narrow range of 3.3ë in d18Oquartz between maximum and minimum isotopic values for the deposit. Significant overlap in d18Oquartz values are observed between the Martha and Welcome lodes. However, statistically significant and commonly systematic differences do occur between individual bands analysed in most samples. Temperature fluctuations may be the dominant factor responsible for observed inter-band variation.

Jan 1, 1995

The interaction between ore-bearing fluids and the siliciclastic rocks typically hosting orogenic gold deposits in Phanerozoic metamorphic terrains result in the development of a distinctive alteration halo. Along with petrological changes such as the replacement of chlorite by carbonate and the growth of sericite, characteristic geochemical modifications take place within this alteration envelope. These include variations in elemental abundances and more or less pronounced shifts in the H, C, N, O, and S isotopic signature of the ore system. æFingerprintingÆ these isotopic trends can provide exploration with additional vectors towards the ore zone, and yields valuable information regarding the source of the hydrothermal fluids and the solutes contained therein. Data from radiogenic isotope systems such as Sr-Rb, Ar-Ar, Xe-Ra, Pb-Pb, Re-Os, Sm-Nd, and U-Pb can constrain the kinematic history of ore-hosting structures, provide important clues concerning the absolute timing of gold emplacement, and enable the detailed characterisation of associated intrusives with respect to their magma source(s) and crystallisation age. Although high analytical costs, long turn-around times and the potential for misinterpretation prevent isotope systems from offering a æquick & dirtyÆ analytical method that would provide a significant advantage in exploration for orogenic gold mineralisation, the development of integrated four-dimensional ore genesis models depends heavily on constraints obtained from isotope mass spectrometry.

Jan 1, 2002

By D James

Fletcher Challenge Limited through its subsidiary Grampian Mining Co Limited has carried out an ore evaluation of one of New Zealand's largest known deposits of ilmenite located at Barrytown on the West Coast of the South Island, New Zealand. The ilmenite is located in a beach sand environment which has previously been mined for gold. Two analytical techniques were developed to quantify the resource. Considerable difficulty was experienced in this phase of the evaluation due to the presence of major inclusions within the ilmenite grains. Wet and dry concentration circuits, utilising spiral, wet magnet, high tension and plate electrostatic separators have been designed to produce ilmenite from the ore. Studies to utilise the titanium content of the Barrytown ilmenite have been made. Recent work has been directed towards a titanium dioxide pigment process.

Jan 1, 1986

Generation and Attachment of Submicron Size Bubbles to Colloidal Solids

Sep 13, 2010

The Ekati Diamond Mine is located on permafrost terrain in CanadaÆs Northwest Territories. The mine rock consists of: diamond-bearing and barren kimberlite; and surrounding waste rock such as granite. The kimberlite occurs in several vertical æpipesÆ that are, or will be, mined using open pits. Early predictions of drainage chemistry at Ekati identified the potential for ARD due to sulfide oxidation from both waste rock and kimberlite. This was surprising for the kimberlite, because neutralisation potentials (NP) are typically hundreds of kg CaCO3 equivalent/t. However, subsequent testwork showed that substantial portions of the NP ædisappearedÆ quickly, apparently due to the unusual non-carbonate mineralogy. In any case, additional predictive work concluded much of the rock was benign and there would be no ARD. Shortly after mining started, ARD appeared from both the waste rock and kimberlite, although a few years passed before the company and its consultants recognised that at least some of the acidic water was ARD. Numerous other processes have been put forward as possible explanations for the remaining acidic drainage, although none have been either confirmed or eliminated. Because: the causes of the ARD and acidity are not known; no causes have been eliminated and more have been added; drainage chemistry was not predicted accurately; and future mining will encounter similar rock. I believe the Ekati Diamond Mine needs high-level assistance to understand current chemistry and to avoid problems with future drainage. Organisations like INAP, MEND3, and universities could provide this assistance.

Jan 1, 2003

Particle Size Measurement of TiO2 Nanoparticles in Non-Aqueous Solvent by Interactive Force Apparatus Under an Electric Field

Sep 13, 2010

By M Quinteiro, Å Sundqvist

What is special about being a female mine manager? We do not believe that the challenge is greater for women in managing a mine compared to managerial positions in other male-dominated businesses. The challenge lies in the fact that it is a male-dominated business. Being a leader belonging to a minority creates a situation where competence not only lies in having technical knowledge or general leadership characteristics, but also in acquiring an understanding of the male norm and being able to behave and communicate effectively in the organisation.In order to move towards a better gender balance at senior levels it is important to set measurable objectives on desirable proportions between women and men at management levels within the company. Focus and action are required to achieve this goal. At LKAB, the current target is to reach 25 per cent women in the total workforce by 2020. To date, LKAB has reached 19.4 per cent women in the total workforce, and the number of women in management positions is 19.9 per cent.It is of vital importance to create a non-discriminating working environment to achieve equal opportunities at the workplace, to be able to use the whole workforce as a resource for recruitment of professionals and managers, thereby improving decision-making, productivity, efficiency and profitability.Women as mine managers is not a utopia, but rather an effect of long-term investments in actions that result in equal opportunities for all employees.CITATION:Quinteiro, M and Sundqvist, Å, 2016. Women as mine managers – a utopia?, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016) , pp 43–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The New Zealand Steel Ironsand Slurry Pipeline was successfully commissioned in February 1986. The project includes 18 km of high pressure, polyurethane lined buried pipe. McConnell Dowell Constructors Limited has developed a coupling which has allowed this pipeline to be fully welded. The design and development of the coupling and its application on this project is discussed.

Jan 1, 1986

By G B. Arehart, S J. Mathews, J L. Mauk

The banded nature of the quartz veins which form the Empire lode at the Golden Cross mine, is perhaps their most striking feature. Petrographic studies show that significant differences occur between the bands in terms of textures, quartz grain size, calcite, adularia and kaolinite content, and the form, concentration and mineralogy of sulfide phases.   The d18Oquartz values of individual bands within the vein material range from 7.3-10.9ë. Calculations show that the d18Oquartz values can be adequately explained by temporal variations in the system temperature, boiling and/or variations in the systems fluid/rock ratios.

Jan 1, 1995

Adsorption Effect on Multi-Heavy Metal Ions in Wastewater by Water-Washing Waste Saccharomyces cerevisiae

Sep 13, 2010

Reasons are given for the seemingly excessive public concern with taxation of the mineral industry. Optimality of mineral extraction is a concept that requires careful definition in terms of one or more objectives. Once defined, the impact of taxation upon optimal mineral extraction may be studied; findings from earlier work on this topic are presented for two basically different cases. In conclusion it is observed that the pursuit of optimality requires the availability of highly skilled engineers; in the event of a large-scale mineral development it is this resource that is probably scarcest of all.

Jan 1, 1983

Methods for Improving the Flotation Recovery of the Coarse Fraction of a Nickel Ore

Sep 13, 2010

Old Copper Flotation Tailings Waste Reprocessing

Sep 13, 2010

By G Akdogan, R V. R Handfield-Jones

The application of microwave energy as a substitute for conventional heating has drawn interest from many researchers in extractive metallurgy. Microwaves have a heating effect just as many other forms of radiant energy. Microwaves are able to penetrate the substance at which they are directed and in being absorbed heat the material from the inside. As a result of heat generated in the interior of a particle, microwaves can affect the rupture of a particle (in this case a host ore) and break down the matrix of the particle (host ore) and expose the recoverable mineral to the leaching reagent. Two series of leaching experiments were carried out at temperatures above 90????C using a conventional heater (hot plate) and a modified 850 W, 2.45 Ghz microwave oven. One series of tests was carried out at ambient temperature. A pyritic/arsenopyritic gold concentrate was leached with 3.3 kg/t to 6.8 kg/t NaCN for two hours. The extraction of gold at 6.8 kg/t NaCN was higher in microwave assisted leaching (59 per cent) than the extraction obtained in leaching at conventional heating (39 per cent) and ambient temperature (28 per cent). Extraction of gold was dependent on the size fraction used and was 48 per cent for û75 ¦m, 43 per cent for û90+75 ¦m and 37 per cent for û150 + 90 ¦m size ranges.

Jan 1, 2000

By M Bourke

Modern computers and software provide powerful tools for the geologist to construct reliable models of geological resources, and the mining engineer to produce accurate and workable mine plans. Over the years many people have developed a phobia of computers, especially for geological analysis, modelling and mine planning. This phobia is often caused by a lack of knowledge, poor training or a bad experience. The adoption however of computers for geological modelling and mine planning is now becoming mainstream. With the correct training, a good understanding of input data, and detailed knowledge of the required results, the phobia can safely be overcome to provide mining operations with increased productivity.

Jan 1, 1999

Separation of Minerals Using Electrical Fields The mineral processing industry requires alternative separation techniques to help deal with rising energy costs and decreasing ore grades. Dielectrophoresis is one possible technology. It uses non-uniform electrical fields to separate particles on the basis of their permittivity. In order to determine its viability, the dielectrophoretic force was measured for individual chalcopyrite particles in ethanol. The measurements were made by attaching the individual particles to glass fibres and measuring how far they were deflected by a non-uniform electrical field. Six sizes of chalcopyrite particles were tested and the force was found to increase as a function of particle radius cubed. The particles were also positioned at different points in the field in order to determine the effect of the electrical field gradient. The force was found to increase with the inverse cube of the distance from the centre of the particle to the pin electrode. With the effect of these parameters fully characterised, the single particle test cell can be used to determine the permittivity of single particles of various composition.

Sep 13, 2010

By D David

The majority of SAG and ball mill design methodologies are applied using a single design value for mill selection, such as the 80th percentile ball mill work index or SMC value. Inherent in the selection of this design value is a desire for the mill to accommodate unfavourable, but not absolute worst case, feed conditions. It has been observed in numerous “post-mortems” of unsuccessful designs and also in many optimisation studies, that the selection of the design value has been poor. Statistical analysis of testwork data sets shows that inherent variability in the data can, by itself, lead to design errors. Metallurgical testing is an attempt to measure the characteristics of millions of tonnes of ore using only a few kilograms of sample. In this paper some realistic but synthetic test work data sets are used to explore old and new methods of defining the design envelope and subsequently selecting a reliable point. The aim of the paper is to provide practitioners with tools that reveal the adequacy (or otherwise) of metallurgical test programs intended to support various levels of project design. It also provide guidance as to how it is possible to statistically justify a comparatively high design point in the absence of adequate test data.CITATION:David, D, 2015. Measuring and taking notice of orebody variability – an essential ingredient for reliable plant design, in Proceedings MetPlant 2015, pp 10–26 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015