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By H Zhang, S Li, J Song, Z Lv

In this paper, a method for extracting and refining metallic molybdenum using low-temperature ZnCl2- NaCl-KCl molten salt was proposed. The electrochemical behaviour of molybdenum ions in ZnCl2- NaCl-KCl molten salt was investigated in detail, and pure metallic molybdenum was collected on the cathode. The reduction and diffusion processes of Mo(V) ions in ZnCl2-NaCl-KCl molten salt were determined through a series of electrochemical methods. The diffusion coefficients and nucleation modes of Mo(V) ions were also studied, and electrolysis was conducted for a prolonged period at a constant current density. The results indicated that the electrode reduction of Mo(V) ions in ZnCl2- NaCl-KCl molten salt proceeds through a three-step reaction: Mo(V) → Mo(IV) → Mo(III) → Mo at 250°C. The Mo(V) → Mo(IV) reaction was reversible and diffusion-controlled, with a Mo(V) diffusion coefficient of 6.02 × 10-6 cm2 s-1. Additionally, the nucleation mode of Mo(V) ions was instantaneous nucleation. The products electro-deposited were confirmed of metallic molybdenum with a particle size of less than 1 μm.

Aug 21, 2024

Mining of copper ore is still the most important business in Chile. In order to mine ore with a copper content of less than one percent at Minera Los Pelambres in an economical way, opencast mining is mandatory. Due to the prevalence of avalanches at the mine, the concentrator was located in a stable area, some distance from the mine. As a consequence, the material has to be transported between mine and concentrator by conveyor. A downhill conveyor system has been implemented for more than ten years as the most suitable and most economical ore transport alternative. Due to the length (12.6 km) and inclination (1300 m drop) of the conveyor system, the stresses in the steel cord belt are the dominant design criterion, resulting in a belt quality of ST 7800. Additional dynamic belt stresses during transient operating conditions are avoided by the installation of high capacity adjustable frequency drives. The rating of a single drive unit is 2500 kW. During ten years of operation, several capacity increases have been implemented, from an initial 5800 t/h up to the current capacity of 9900 t/h. This presentation describes the engineering challenges of the implementation of the world's strongest belt conveyor system. Capacity increase measures like the development of new control and breaking strategy, proved by dynamic simulation of belt forces and belt speed scenarios are explained. During this long-term partnership of RWE Power International, the former Rheinbraun Engineering, with Minera Los Pelambres, RWE has been engaged continuously for development work, safety checks, expert opinions and maintenance audits, and giving new impulse to conveyor technology.

May 1, 2010

The Airport Link Railway utilises innovative solutions to a number of issues associated with underground development and transport infrastructure planning. It is typical of the major change underway in the countryÆs rail and air transport industry. It involves the private sector providing transport facilities in competition with the public sector, a convergence of planning and transport imperatives, the use of the most technologically advanced engineering practices to minimise construction impacts on the community and a commercialised way of developing and maintaining railway infrastructure and services.

Jan 1, 1999

By J Sargeant, T Levi, J Theiler, B Beamish

Two coal samples (810 Panel and Area 900) collected from Clarence Colliery have been tested under a controlled heating procedure to evaluate the gas evolution trends corresponding to increasing temperature. Gas evolution data are normally used to identify key gas indicators and validate the trigger action response plan settings for the mine as part of the Principal Hazard Management Plan for Spontaneous Combustion. The samples were located some 6 km apart and there is a significant coal-type difference between them. At low temperatures (<100°C), the Graham’s ratio (GR) values for the two samples are almost identical. However, at elevated temperatures, there is a significant difference, with the 810 Panel coal having higher GR values than the Area 900 coal. This is most likely due to a difference in the coal reactivity. The 810 Panel coal does not evolve ethylene until temperatures in excess of 140°C are reached, whereas Area 900 coal evolves ethylene once temperatures in excess of 120°C are reached. The 810 Panel coal also produces significant ethane evolution (200 ppm) at low temperatures (50°C) due to the presence of retained ethane seam gas, which decreases as the temperature increases due to desorption from the coal. Once the coal temperature exceeds 130°C, the ethane evolution increases again due to coal oxidation reactions, reaching levels of 50 ppm. In contrast, the Area 900 coal has no significant low-temperature ethane evolution, and ethane evolution only increases once the coal temperature exceeds 120°C. There are also noticeable differences in the trends of other gases evolved from the coal. These findings have implications for the interpretation of gas monitoring results from the two different areas of the mine. They also illustrate the need for obtaining results from each new area of a mine as it develops so that changing gas evolution trends can be identified in advance of mining.CITATION:Beamish, B, Sargeant, J, Levi, T and Theiler, J, 2015. Gas evolution trends for coal from two different areas at Clarence Colliery, in Proceedings The Australian Mine Ventilation Conference, pp 273–278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

The purpose of this paper is to outline current research on the Paparoa and, at the request of conference organisers, to present a general introduction to the geology of the Greymouth Coalfield as background to more specialised papers. Few results of my present work will be given; these can be presented at the next conference. Briefly, the research aims for an understanding of the controls which depositional environment has exerted on coal character, to be reached by a study of coal type and thickness, shape and extent of seams, integrated with a basinal analysis of the coal measures. An accurate description of the coalfield in these terms should facilitate prediction of subsurface trends, with possible application to the planning of drilling programs, and to mine development. Although study of Paparoa coal types is included here as only part of the research, coal type should be recognised as an important concept which has until revently been almost entirely neglected in New Zealand.

Jan 1, 1979

By N Takamatsu

The environments surrounding the iron and steel industry have changed greatly in recent years. Reported in this paper are the technologies adopted by the Japanese iron and steel industry to fititself to change in global steel demands, degradation of iron ore and coal, prolonging service life of the facilities and requirements of energy saving. In addition, innovative technologies for CO2 emission control in iron making processes are also discussed.

Jul 11, 2011

By J Wen, P Hou, W Yu, M Hu, Z Jiang, C Bai

Vanadium titano-magnetite (VTM) is one of the important iron ore resources in the world. High viscosity and low fluidity are the basic characteristics of hot metal containing vanadium and titanium during the ironmaking process. Clarifying the influencing mechanism of the melt viscosity would be a significant issue for the high efficiency smelting of VTM. In this paper, a self-developed melt viscometer based on the principle of torsional vibration theory was employed to measure the viscosity of hot metal accurately. Simultaneously, the thermodynamic calculations and some modern detection methods were also used to investigate the precipitation behaviour of high-melting-point phases in hot metal containing vanadium and titanium. The measuring results show that the viscosity of molten iron gradually increases with the increase of titanium content when the mass fraction of titanium is between 0.09 wt per cent – 0.50 wt per cent. Meanwhile, the viscosity of the hot metal was affected significantly by the vanadium content. When the vanadium mass fraction was higher than 0.30 wt per cent, the viscosity of hot metal increased sharply, which will have a serious impact on the fluidity of the hot metal. Furthermore, it was revealed by thermodynamic calculations that an increase in titanium and vanadium content would result in the precipitation of high melting point phases such as TiC, TiN, VC, and VN in the molten iron, ultimately resulting in a decrease in its fluidity. Meanwhile, it was confirmed by Scanning Electron Microscope (SEM) observation that the precipitates in the hot metal were compounds consisting of V, Ti, C, and N elements, which agrees well with the thermodynamic analysis results.

Aug 21, 2024

By D Woolmer

Since January 2019, BHP Olympic Dam have been trialling the use of a drone based LiDAR mapping system for the purpose for surveying stope voids. This new technology utilises Simultaneous Location and Mapping (SLAM) algorithm providing positioning, stability and collision avoidance in GPS denied environments. Implementation of this system utilised underground personnel trained in the equipment’s use. The study’s intention was to evaluate the effectiveness of this equipment versus traditional surveying methods in regards to quality, safety and productivity. The trial results showed a marked improvement in the quality, productivity and personnel safety when conducting surveys. The use of the drone and LiDAR system reduced personnel and equipment requirements for surveys, thus allowing these resources to be deployed elsewhere. The technology’s simple and rapid deployment allowed multiple surveys to be conducted during a 12 hour shift, including ad-hoc work with minimal disruption to underground operations. After the drone’s initial trial, further work was conducted to utilise the Hovermap LiDAR scanner on other platforms to increase utilisation. A mounting system was created allowing the LiDAR to be mounted on a remotely operated loader or vehicle. This enabled drawpoint scans to be taken directly after production completion, resulting in faster stope close outs and drive scans for convergence monitoring. Implementation of the LiDAR system has resulted in improvements in the stope production cycle by reducing delays previously associated with data capture. The increase in the volume and quality of data has also allowed in-depth back-analysis of stopes in new mining areas to be conducted, which have driven improvements in the design process.

Mar 15, 2021

The following paper on the development of processes for the treatment of crude ore, accumulated dumps of tailing and slime at Broken Hill, has been prepared by a committee of the Broken Hill Branch of the Australasian Institute of Mining and Metallurgy, with the object of recording, in chronological order, the developments of the various processes which have led up to the metallurgical practice of the present day.

Jan 1, 1930

Within ten months of the first significant intersection on the Vera deposit, approval was given to proceed with a $28.3 M underground development of the Vera-Nancy gold mine. Contrary to what the timeframe suggests, the development of the underground mine was planned in a logical and methodical manner which enabled confirmation of the resource, evaluation of the orebody for mining and sufficient production to recommence milling operations at the Pajingo treatment plant. This paper describes the underlying factors on which the project was planned and developed. The approach has successfully enabled the mine to be in production 18 months after discovery without compromising any future production or potential expansion

Jan 1, 1998

Bendigo Mining operates a 600 000 t/a comminution, gravity, flotation and leaching processing plant for the recovery of gold from their Kangaroo Flat Operation, in the Bendigo goldfields. The free gold and gold bearing sulfi des present are typically coarse grained and hence are highly amenable to gravity recovery. Plant operating data is consistently showing that over 78 per cent of the feed gold is recovered in a circuit, consisting of inline pressure jigs, inline spinners followed by free gold tabling and intensive leaching of tabling tails. The circuit receives coarse crushed product from high pressure grinding rolls and the grinding mill discharge, which allows material to be re-circulated through the gravity process until the particles are small enough to enter the flotation circuit. A plant audit was completed on 26 November 2009 designed to give an indication of the overall operational characteristics of the gravity circuit including single pass efficiencies of associated equipment. The techniques, results and challenges of such a survey are discussed.

Aug 1, 2010

By W N. Qin, B Zhang, W Z. Huang, X S Mo

Mengzi Mining and Metallurgy Co, Ltd (MMMC) polymetallic ore contains recoverable amounts of tin, lead, zinc, pyrite and other valuable minerals. With the change in orebody, the run-of-mine (ROM) ore changed from lead zinc rich ore to tin rich ore, where the current ROM ore contains 0.45–1.25 per cent tin, 20–25 per cent sulfur, and 0.20–0.35 per cent copper. The previous processing flow sheet was designed to recover lead zinc rich ore and it is clearly not suitable for recovery of the current tin rich ore, where the tin was already overground and tin recovery was only 50.19 per cent. The Mengzi Mining Company has recently modified the concentrator circuit by incorporating rod mill and high efficient Derrick fine screen. As a result of the improved classification efficiency, the overgrinding of the tin ore was minimised and the recovery of tin was improved by 20.71 per cent, ie from 50.19–70.90 per cent. An additional $10 M revenue per annum can be achieved as a result of the modification.CITATION:Qin, W N, Huang, W Z, Mo, X S, Zhang, B and Wheeler, J, 2014. Application of high efficient fine screen to improve the recovery of tin concentrate, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 487–492 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

The Western New South Wales Electric Power Proprietary Limited is the central generating authority for distribution of power to the majority of the Broken Hill mining companies and the Broken Hill Water Board. This station supplies the whole of the power to North Broken Hill Ltd and Broken Hill South Ltd. It also supplies, power to the Southern Power Corporation for distribution to the Zinc Corporation Ltd. The Southern Power Corporation has a generating station which is tied in with the central generating authority.

Jan 1, 1957

Ecological Fuel from High-Sulfur-Content Coal

Sep 13, 2010

By Patterson B. G

The small party of mining men who formed the original Mount Morgan Syndicate in 1882, commenced operations on the top of the mountain with what were practically nothing more than small hillside quarries, It was not until 1891 that underground stoping began, and open-cut mining therefore commenced with the commencement of operations. This hillside quarrying, however, seems to have been quite haphazard and unsystematic ; there is no trace or sign of any properly devised mining scheme. This can be seen plainly enough from an examination of old mine plans; for in less than five years after stoping was; adopted, the open-cut was down into the stoped-out ground. The following table, prepared from these old plans, shows the downward trend of the excavation in the past fiftyseven years:-

Jan 1, 1939

This paper presents the descriptions of a final year geological engineering project at the Royal Melbourne Institute of Technology involving the correlation of borehole and mapped ground conditions and their statistical Analysis.

Jan 1, 1994

By F Pothitos, S Hewson

The geological and geotechnical conditions at the Cadia Hill Open Pit are very complex. This complexity coupled with high mining rates has required significant technical input into the design and optimisations of the pit slopes, accesses, cutbacks and scheduling. A multi-discipline team of NML engineers, geologists and external consultants has been conducting comprehensive geological and geotechnical programs in order to achieve an optimum design of the pit slopes. Extensive data collection, analysis and interpretation has led to the formation of working geotechnical models of large structures, rock masses, and back-analysed slope performance charts. The current Cadia Pit Optimisation Project focuses on the risk-and-return principle for pit design and on the integration of geotechnical, hydrogeological, mining engineering and scheduling. The risk management for pit design has also been incorporated into the short term and long-term operation of the pit mining to ensure safety and production.

Jan 1, 2003

By C Thompson, D Connelly

The history of mill liners has evolved over time and this paper tracks the changes and development of liner technology. It provides an overview of the primary types of liners, the design and the materials of construction. The design of a mill liner is driven by application, materials of construction, casting technology and handling issues. The choice of solid steel, grid liners, rubber or composites and magnetic liners is based on many factors.The methods used for monitoring wear and predicting eventual change out time are many and varied. The contribution of discrete element modeling (DEM) analysis in predicting wear profile is discussed.Mill trajectory and DEM software programs are used with great effect to predict the effect of lifter height, face angle, high low lifters or mill speed. In the field, trial and operational experience is used or improvements/design concepts at one operation are applied to another. Broken mill lifters, accentuated wear and other problems can be better understood using hardness testing, chemical analysis and photo micrograph analysis of pearlitic or martensitic structure along with fracture face observations. This forms a part of the typical root cause analysis. However given correct and sound liner and lifter, feed and discharge design media selection, and materials of construction, the majority of premature liner or bolting failure is normally attributed to incorrect operational methods such as excessive high ball to feed ratio, incorrect mill speed relating to lifter ball throw, incorrect media selection, "tramp" material entering the mill charge from upstream or recirculating process and understanding the specific mill operation in question.It is hoped that this paper will benefit mill operators who are faced with challenges of improving wear life and at the same time optimizing mill throughput and performance.CITATION:Connelly, D and Thompson, C, 2013. The selection design and application of mill liners for large wet grinding mills, in Proceedings MetPlant 2013 , pp 133-140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By T Muri

The drying operation of materials from particulate solids, through slurries and suspensions, to continuous sheets represents an important part of several processes in the chemical and mineral industries. The increasing demand of high productivity at low cost and minimal environmental impact makes it complex to evaluate and choose the best available drying technology for each industrial application. The drying technologies are mainly characterised on the basis of how the wet product is related to the drying medium, namely: direct and indirect drying. In the direct drying method (convection drying), the product is brought into direct contact with the drying medium, which may be hot gas or air. Large quantities of gas are necessary for transfer of the required energy. A special case of the direct dryer is the fluid bed dryer, in which the product floats on a cushion of air or gas. The process air is supplied to the bed through a perforated distributor plate and flows through the bed of solids at a velocity sufficient to support the weight of particles. Very high heat and mass transfer values are obtained as a result of the intimate contact with the solids and the relative velocities between individual particles and the fluidising gas. In the indirect drying method (conduction or contact drying), the wet product is separated from the drying medium. The drying unit can consist of a rotor forming the indirect contact heating surface mounted in a stationary or rotating shell. The indirect method uses saturated or superheated steam resulting in low energy consumption and minimal environmental impact. In this paper, a review is given of the technologies available on the market based on different drying methods. The advantages and the disadvantages are summarised with respect to issues such as investment and operating cost, maintenance, product capacity, product handling and environmental impact.

Jan 1, 2006

IN the recent monograph on Broken Hill, N.S.W., by E. C. Andrews,* two independent petrological reports appear as Appendices 1 and n, by W. R. Browne and F. L. Stillwell respectively. In these considerable differences of opinion occur. Andrews contributes to some of the questions at issue, but no analytical review of the differences appears in the body of the report. Their development may invite question, and the following notes have been prepared partly in explanation and partly as a summary of some of the divergences. The soope of Browne's report extends over the whole district of Broken Hill, while Stillwell's deals with the rocks within 25 chains of the main lode. The more difficult and important rock-types occur in both areas, raising similar questions. In both cases observations extended beyond the limits of the prescribed areas. Broadly, Browne faces his problem as a study of a series of primary igneous rooks, acid and basio, whioh are intrusive into a series of sillimanite gneisses. The development of the sillimanite gneisses is regarded as belonging to an earlier period than the intrusion of the igneous rooks, while the gneissio structures of the latter are features which are incidental to their orystallization, and are not acquired subsequent to their consolidation. He finally produoes a picture in which his views of igneous injection and differentiation takes a prominent place. One direct result is the claim that three separate periods of metamorphism have oocurred in the Broken Hill area. Stillwell primarily examines the rooks as schists and gneisses since their present dominating features have been acquired during metamorphism. The effort is made to understand suoh differences as might arise from differing conditions of metamorphism upon rocks of similar and different oonstitution. The aim is to divest the rocks of those oharaoters which are due to metamorphism before approaching the questions of intrusive relatio'nships between igneous rocks andsediments.

Jan 1, 1924