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By A Batnasan, K Haga, A Shibayama, K Higuchi, H Takeuchi

High silica (SiO2), alumina (Al2O3), and phosphorus (P) contents in iron ore adversely affect the quality of iron products. The removal of those impurities from iron ore is an essential point in further iron ore processing. In this paper, the removal of P, SiO2 and Al2O3 impurities from iron ore by alkaline drying followed by reverse cationic flotation is discussed. The reverse cationic flotation experiments are performed using the iron ore samples without and with alkaline drying pretreatment. All other flotation conditions except pulp pH (4–12) and particle size distributions (-45 to -250 μm) are held constant. A typical collector and frother, such as dodecylamine acetate (DAA) and methylisobutylcarbinol (MIBC), are used in the flotation experiments. Alkaline treatment is conducted before flotation using sodium hydroxide at fixed conditions. The impact of alkaline drying on the performance of iron ore flotation is evaluated based on the removal rates of P and SiO2 + Al2O3, iron grade, and iron recovery compared with the iron ore flotation without alkaline drying (direct flotation). X-ray diffraction (XRD) analysis indicates hematite and goethite are the main minerals in the iron ore, which assays 62.8 mass per cent Fe, 0.232 mass per cent P, 7.1 mass per cent SiO2 + Al2O3 (total) determined by X-ray fluorescence analysis (XRF). Results indicate that a combined approach is more effective for removing P and SiO2 + Al2O3 impurities from iron ore than the direct processing technique because the maximum removal rates of P and SiO2 + Al2O3 are 48.2 per cent and 66.5 per cent from the alkaline dried iron ore when 8.4 per cent and 13.1 per cent from the non-alkaline dried iron ore.

Sep 18, 2023

In early 1985, Bougainville Copper Limited commissioned an automatic truck despatch system to control its fleet of 44 trucks and 9 shovels. Productivity gains in the past have been the result of increasing equipment size then improving availabilities. The emphasis now is on improving the use of that availability and in particular for trucks, in reducing non-productive truck movement. A batch allocation computer based truck control system had been in operation since 1978, so to achieve the desired improvements it was necessary to move to an automatic dynamic control system. A description of the system installed is given, together with a review of how the project was engineered, the problems encountered and the results achieved to Date.

Jan 1, 1986

The South Comet mine is an underground silver-lead-zinc mine located on the West Coast of Tasmania with an annual production in the order of 35 000 tonne per year. All ore mined is shipped to the Rosebery mill by road, a distance of 17 km.

Jan 1, 1993

By W A. Tchernykh, R P. Strelnikova

In connection with the fact that technology of ore mining by caving system is often used when mining of deposits, characterising by low stability of surrounding rock mass, the main problem for such ore mines is ensuring stability of mine workings, placing in a zone of influence of winning operations. Besides natural disturbance of ore mass, stability of workings depends on the dynamic effect of blasting operations and also on the dynamic effect of structural blocks detaching from the ore mass and colliding with crests of ore pillars in the bottom of a chamber. Decreasing of dynamic stresses may be achieved by way of creation of a compliant porous screen or an ore cushion in the chamber bottom. It is established that maximum levels of compression take place when the first impact impulse occurs, and after that increase of compression of protective slice decreases. Necessary thickness of screen slice was substantiated theoretically with due account of height of structural blocksÆ fall, their mass, deformation modulus of ore mass and ore cushion.

Jan 1, 2003

By N McIntyre, R Trancoso, N Bulovic

Mining is essential for facilitating human development particularly as demand for critical minerals grows. However, over the mine life cycle, the environment is permanently changed. Once mining ceases, mine-affected land can leave significant legacy issues on the surrounding environment if not managed. Therefore, mine closure planning is critical. Mine closure occurs over large scales often with the aim of recreating resilient ecosystems over mined landscapes with mitigated negative impacts. The natural state of the landscape and the environmental risks over planning time-scales are largely driven by climate. Climate change is expected to impact different parts of the post-mining landscape, from stable landform design (soil erosion mitigation) to revegetation efforts and pit lake management. Consequently, mine closure plans may need to account for a non-stationary and uncertain future climate, that may be both different to the current climate and evolve during the mine life and post-closure. Here a new data-based approach is presented for incorporating climate change projections in mine closure planning, based on the recently released Coupled Model Intercomparison Project phase 6 (CMIP6) climate data used in the latest Intergovernmental Panel on Climate Change (IPCC) assessment report. The approach: (i) characterises closure-related attributes of the future climate, and (ii) identifies the amount (and direction) of change expected to occur, and its uncertainty, focusing on five metrics for demonstrative purposes and initially describing changes in erosive potential below. This provides information on the type of future environment (ie the changing baseline) that mine closure should plan towards, and identifies rehabilitation options that may be susceptible to increased risks from climate change.

Aug 2, 2023

Reverse circulation (R.C.) drilling or the dual tube method as it is quite commonly known, has a unique place in conventional mineral drilling. It can be classified half-way between open hole drilling at the lower end of the scale and diamond drilling at the upper end. The system basically consists of two tubes, one inside the other, with compressed air flowing between the inner and outer tubes. Sample cuttings return up the inner tube through the head of the rig and via a hose to a cyclone where the sample is collected. This system means that the cuttings are free of contamination as they are at no time in contact with the outside formation of the hole.Reverse circulation drilling is divided into two areas: R.C. Roller and Blade for softer formations; and R.C. Percussion for harder formations.

Jan 1, 1986

The process of defining the external environmental costs of mining activities, devising appropriate mechanisms to internalise them is complex and is likely to be a gradual.Australia's competitiveness could be seriously affected if , in terms of incorporating environmental costs, we were to exceed other resource producing nations.Australia has a great deal at stake in the debate and therefore we need to proceed carefully and be fully aware of the environmental and economic issues.

Jan 1, 1992

An algorithm is described which leads directly to a unique set of coal washing parameters which, in two or more parallel streams, will give maximum yield of product at a given ash. This occurs when all parallel streams are washed to the same incremental ash. This strategy is shown to offer a considerable increase in yield compared to the simpler strategy of washing each stream to the same sumulative ash.

Jan 1, 1987

An integrated mining equipment development organisation is typified by Deutsche Montsn Technologic of Essen, Germany. working on improvements in reliability, production and control in coal mines. Examples of recent mining advances are in mechanised roadheading, in different approaches to cutting technology, and in low height roof bolting.On the longwall face the mechanics of cutting are related to supplied energy as well as to dust make. In conveying both armoured face conveyors and conveyor belts are monitored. Roof support is not neglected and the continuous pumping of stowage slurries provides further options for longwall support. Surveying developments, particularly the gyro-theodolite, directional drilling. and shaft vehicle monitoring provide further examples of advances in control in coal mining activities.

Jan 1, 1991

By P Radulovic, W Y. Lui

The Mount Isa Mines (MIM) copper concentrator at Mount Isa processes both chalcopyrite ore from the MIM underground mine and rotary holding furnace (RHF) slag from the MIM copper smelter. There have been numerous changes to the processing practices since commissioning this concentrator in 1973. Current management of the concentrator extends from grinding and flotation to concentrate handling (thickening and filtration) and tailings disposal (fill plants, tailings thickeners and process water systems).Predominant mill feed through the concentrator is chalcopyrite ore. RHF slag is processed when concentrator production exceeds mined ore production. The chalcopyrite circuit has two stages of grinding in parallel lines (Line 1 and Line 2). Each line has parallel preflotation and rougher banks, combining into a common scavenger/retreat circuit (including regrinding) and common cleaner circuit. RHF slag may be milled in parallel with chalcopyrite, utilising Line 2 flotation roughers and a Jameson cell cleaner. All final concentrate produced is combined and pumped to the concentrate handling plant. The concentrate is thickened, pre-fluxed and filtered in hyperbaric disc filters. Fluxing specification is set by the copper smelter, and filtered product transferred via conveyor belt to the smelter concentrate storage facility.Wet fill and paste fill plants utilise flotation final tailings as hydraulic or cemented hydraulic fill for stopes underground. Cement ratios and fill plant utilisation are varied depending on underground stope fill requirements. Tailings from the adjacent lead-zinc concentrator are also processed at wet fill. All tailings that are not utilised for backfill are pumped via wet fill to three parallel tailings thickeners. Thickener underflows are gravity fed to the tailings dams with thickener overflows recycled for site process water use. In addition to summarising historical operations, this paper will provide a detailed outline of more recent changes in the concentrator flotation circuit, equipment upgrades, reagent optimisation as well as product and process optimisation at the final concentrate handling and fill plants.CITATION:Lui, W Y and Radulovic, P, 2013. Mount Isa Mines copper concentrator - An insight into current and historical practice, in Proceedings MetPlant 2013 , pp 553-574 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

There have been many developments in recent years in pipeline transport to enable them to be more widely used in industry. Substantial tonnages of materials that are not affected by water, such as coal and other minerals, aggregates and wastes, can be moved over considerable distances in quite small diameter pipes. Where there are no existing road or rail facilities, long-distance pipelines are usually cheaper to install, and this advantage increases in difficult terrain. Pipeline operators all over the world assert that hydraulic lines pay for themselves in a relatively short time, in spite of the heavy capital outlay, and this is equally true for lines convey-ing slurries or pastes within a plant complex.'This paper reviews some of the more important investigations in the hydraulic transport field. Although reference to systems carrying a wide range of materials is made, the majority of recent published data centres on coal transport.The paper looks at the application to a wide range of particle sizes, the development of non-aqueous slurrying media and coal/water fuels. The review also looks at some of the equipment being proposed to provide more reliable operation and in particular the range of solids-handling pumps now available.-The paper goes on to identify areas where further research and development is required and some of the many organisations undertaking this work.

Jan 1, 1985

By B Madeja-Struminska

The method of evaluation of the approximate temperature of arising spontaneous fire centre and time of coal self-ignition is presented in this paper. The method uses BystronÆs (1997) model of coal self-heating and measurement of carbon monoxide concentration in the mine air outside the fire centre. Knowledge of the spontaneous fire centre temperature and time of fire beginning allows for more accurate analysis of the fire hazard in the coal mine and allows for adequate time to undertake special fire prevention actions. The method is illustrated by an example from Polish mining practice.

Jan 1, 2005

By D S. Terekhov, N Victor, M F. OÆMeara

The current extraction method of the Platinum Group of Metals (PGM) from an ore concentrate and the subsequent separation of one PGM metal from another is a timeconsuming complicated multi-step process. The use of the Chemical Vapour Metal Refining (CVMR) process for the extraction and separation of PGMs is a simple and economical alternative. The paper covers the CVMR process, which is based on the formation of volatile metal compounds, followed by extraction and thermal decomposition into the pure metals and reagent gases. In the case of PGMs, CVMR does not use CO, and hence, the process is quite different from the carbonyl process previously attempted by a number of organisations and test facilities. CVMR extracts PGMs via synthesis of trifluorophosphine complexes at low pressures and low temperatures (80 to 100¦C). These two facts alone make the process highly economical, compared to other methods available. This paper presents a comparison between the process of extraction of PGMÆs and CVMR proprietary carbonyl process for the extraction of nickel and cobalt. In the carbonyl process, CVMR also uses very low pressures and temperatures, compared to those other processes currently use.

Jan 1, 2002

By B Bonfils, P Lois Morales, C Evans

One of the main challenges for current and future mining and processing methodologies is to understand the characteristics of the rock so that its behaviour in one or more parts of the mining process chain can be predicted. Features such as rock texture, mineralogy or border complexity between minerals control how the rock behaves from the processing plant through to the final products, including tailings disposal and thus can affect the feasibility of the project from technical, economic and environmental impact perspectives. Understanding how the mineralogy and texture of rock affect its behaviour in mineral processing is a demanding area of research and is essential knowledge in predicting the processability of complex ores in different stages. This study aims to demonstrate that different types of relevant information can be extracted from a range of currently available analytical methods. However, this information can be used in a complementary way for building a more comprehensive rock characterisation at the microscale and better-predicting ore processing characteristics from the intact rock through to tailing disposal. CITATION: Lois Morales, P, Evans, C and Bonfils, B, 2018. Multisource rock characterisation at microscale for a better understanding of processing characteristics, in Proceedings Complex Orebodies Conference 2018, pp 44–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

The need to estimate the block size distribution of a jointed rock mass is of great importance in the design of blasting rounds to attain a pre- established fragmentation. Other Geomechanics topics, such as ,hydraulic behavior of rock-masses, as well as the determination of their strength properties, also require the accurate prediction of a rock-mass composition in terms of block size taking in due account the three dimensional interference of joints and other geologic discontinuities. In this paper, a method for computing the block size analysis of a jointed rock mass is described, using as input the common geologic data (dip and strike) of fracture planes existing in a rock bench prior to blasting.

Jan 1, 1977

Mineral sands are being used as the source material for new "high-tech" engineering materials. One such material, Magnesia Partially Stabilized Zirconia (PSZ) has been developed and patented world-wide by CSIRO. Derived from zircon sands, the material is currently produced by Nilcra Ceramics in Australia and is exported world-wide.The properties of the material are contrary to those generally accepted for ceramics and are far more akin to those of steel. The material resists not only abrasive wear, impact and thermal shock, but does so under corrosive conditions that frequently cause early failure of metal and cemented carbide.While the consumption of mineral sands for the production of PSZ is not going to significantly increase the demand in the short term, the material itself may well assist the productivity and processing problems within the industry.

Jan 1, 1986

A mathematical model for spontaneous combustion of coal with moisture included is presented in this paper. The one-dimensional unsteady state model consists of conservation equations for oxygen, water vapour and inherent moisture of coal and energy for both gaseous and solid phases. A first order Arrhenius reaction rate for oxidation under both pore diffusion and chemically controlled reaction regime is considered. The rate of evaporation or condensation is also considered as a function of temperature of coal, water content of coal and gas streams. The equation of the model is solved numerically by the finite difference technique. Influences of different parameters on the process of spontaneous combustion can be examined by using this model. Also the model can be used to simulate full-scale storage conditions.

Jan 1, 2005

By W T. Pate, A V. Potapov, J K. Lichter

Even though flotation is one of the most important unit operations of mineral processing, accurate modelling of this process for plant performance prediction has remained elusive. In the last four to five years dramatic changes have occurred in our ability to make credible model based predictions. This paper briefly traces the history of flotation modelling from simple (lumped pulp-froth) æchemical kinetic analogueÆ models for single cells to more detailed multi-phase, multi-component population balance models for banks of cells. It then focuses on recent developments in physics-based modelling tools. This includes current efforts to model the forces of attachment and detachment at the individual event level as well as multi-event levels in individual cells and circuits. Two examples of these tools are presented. The first is DEM modelling of the mechanics of motion of bubbles in froths. The second is population balance modelling of the dynamics of flotation circuits describing how they are influenced by upstream processes (such as crushing and grinding) as well as internal process variables (such as aeration, agitation and reagent addition). Applications of each of these tools are discussed.

Jan 1, 2005

Flotation science and technology are related to three major sub- processes which are organized in a hierarchical structure as shown in Fig. 1. The basic sub-process is the chemical process which affects the attachment of air bubbles to mineral particles. In particular, the chem- ical process is related with the adsorption of surface active sub- stances at the gas-liquid, liquid- solid, and gas-liquid-solid inter- faces. This field has been most intensively explored in flotation research. The second domain in flotation research is concerned with the mineral particle to air bubble attachment sub- process in the system. This sub- process represents the dynamics of particle and bubble encounter where the contact angle and the induction time, determined by the surface chem- istry of the system, are among the most significant parameters. This sub-process can be referred to as the micro-process as against the third sub-process, or the macro-process, which corresponds to the integral behaviour of the system. Two other sub-processes are integrated into the macro-process in which they may not reveal themselves explicitly in the details. The third sub-process does not entail surface-chemical or physi- cal events any more, but it represents them all inclusively. To represent this sub-process we use mathematical equations, called models. Only in some simple or simplified cases can the models be solved exactly to find out the behaviour of the flotation system in which we are interested. Digital

Jan 1, 1984

By M Pernechele, U König

Most of the operating steelmaking capacity currently relies on conventional, coal-based steelmaking processes. Currently, direct reduced iron (DRI) is only produced in regions where energy is available at low cost. To align with net-zero emissions goals, steelmaking capacity must transition to loweremissions steelmaking technology. Direct reduction of iron ore will get one of the preferred methods in the future due to its high technology readiness. New reduction technologies include hydrogenbased direct reduction processes. To ensure optimal efficiency during DRI production and to cope with newly developed technologies, processes need to be monitored more frequently and accurate. Traditionally quality control of raw materials and DRI has relied on time consuming physical testing, wet chemistry or the analysis of the elemental composition. The mineralogy of DRI that defines its properties is not frequently monitored. Process monitoring and quality control of DRI is possible by using modern X-ray diffraction (XRD) methods. In addition to the metallic iron content (Femet), metallisation (Metn) and the total carbon content (Ctot), XRD analysis also identifies the overall mineralogical phase composition. This allows additional information about the reduction process and enables fast counteractions on changing raw material mixtures. The benefits of the quantitative determination of the phase composition and the calculation of process critical parameters to produce DRI will be demonstrated with a case study

Sep 18, 2023