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By W Blair, J Bosman

The measurement of ferrosilicon rheology and characterisation of the parameters that have a direct influence on medium rheology provide the basis for evaluating, comparing and selecting an appropriate size and shape of medium to maximise separation efficiency in a dense medium application. The role of medium viscosity on particle separation in both static and dynamic separators is illustrated using relevant theory. The primary measurements of rheology are medium viscosity and stability. These in turn are determined by particle size, particle density and particle shape which in turn can be quantified. Additional characterisation parameters are also discussed. Different areas of application where ferrosilicon characterisation can be used are also discussed.CITATION:Bosman, J and Blair, W, 2017. The practical characterisation of ferrosilicon for dense medium applications, in Proceedings Iron Ore 2017, pp 135–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By M J. Nugus

The Geita gold mines in north-western Tanzania have produced 5 Moz of gold from an estimated endowment of 15 Moz. They are generally classified as typical Archaean orogenic banded iron formations (BIF)-hosted gold deposits in banded iron formations as described by Goldfarb, Groves and Gardoll (2001); Neall and Phillips (1987); Phillips and Powell (1993) and Neall (1987). The controls on gold mineralisation have been reassessed to conclude that Nyankanga, and we conclude that Nyankanga, the largest deposits within the group, developed during a dynamic and protracted deformation history intimately associated with several stages of hydrothermal fluid flow and alteration. The fluid-induced fractures associated with gold mineralisation are primarily manifested as submillimetre to metre-scale fractures and breccias developed preferentially in rocks that have been previously deformed and altered by silicification or seafloor metasomatism. This realisation detracts from the exploration and mining strategies that would solely concentrate on fluid pathways and associated wallrock alteration and veining solely within the BIFs as hosts for economic gold mineralisation.

Aug 22, 2011

The Influence of Particle Shape in Rock Fracture

Sep 13, 2010

Two key elements in the design of a pastefill or high density hackfill system are the preparation of the backfill material and its distribution underground. This paper examines these two areas. Owing to the essentially impervious nature of total mill tailings, preparation of pastefill and high density fill from current tailings involves a physical dewatering process. There are currently three methods available for this process: I. Vacuum or pressure filters. These represent the 'traditional' approach to the preparation of pastefill. 2. Paste production storage mechanism. This is a thickening/storage mechanism developed with the specific objective of producing paste/high density backfills. 3. Fluidization. This system utilises silos fitted with simple dewatering devices and nozzles. Recently developed by CANMET, it provides the simplest and most economical approach. This paper describes and compares the three preparation methods, from a practical and an economic point of view. Once the pastefill/high density fill has been prepared and binder added, the backfill must be distributed underground into the stopes. A fundamental factor in the design of a distribution system is the rheology of the material- No two materials will exhibit the same properties, and a sequence of rheological and related testing is required prior to the completion of the design of the underground distribution system. This paper covers the testwork normally required and discusses the fundamental design parameters of pastefill distribution systems. The final section of this paper summarises the use of pastefill at three mincsin Canada.

Jan 1, 1998

By I P. Hodkinson

SMC Resources Limited is implementing a selective mining approach at the Hadleigh Castle mine, formerly operated by Aurora Gold Limited. The main ore zone has a length of 250 metres and dips at 40 - 45¦ to the south. Gold mineralisation occurs in a variety of quartz-sulphide lodes in sericitised granodiorite. Shallow dips, alteration intensity and mineralisation style combine to make mining relatively difficult. Previously unworked, high-grade, shallow dipping (30 - 45¦), narrow quartz-sulphide lodes within the hanging-wall of the deposit are also being selectively exploited. Annual production of 35 000 oz Au is forecast from 185 000 tpa ore grading 6.5 g/t Au over a currently envisaged mine life of six years. Operations completed to-date include deepening the decline and access development of the first two levels beneath the previous workings. Longhole stoping operations have commenced in the main ore zone with air leg stoping also underway in the hanging wall lodes.

Jan 1, 1998

Study on Oil Agglomeration Flotation for Deinking

Sep 13, 2010

By P Hagan, S Campbell

A study was undertaken using various methodologies to determine the optimum loading and hauling configuration for different haul routes at Callide Mine, a coal mine located in central Queensland. The study involved development of an effective flat haul model that was used to estimate production rates in truck and shovel circuits that employ two excavators of differing capacities then Queuing Theory to construct a capacity constraint model for scheduling purposes to assist in truck allocation and finally a cost model to determine the most cost effective fleet configuration.The model was calibrated using haul road design and performance data of trucks and excavators currently in use at the mine. The study examined the effects of cycle time for different truck and excavator fleet configurations on production rate and costs.The study found haulage cost was directly related to cycle time while production rate reduced with cycle time. The study indicates the approach taken in combining a cost model with a capacity constraint model offers a simple and effective method of scheduling an optimum number of trucks in a haulage circuit.CITATION:Campbell, S and Hagan, P, 2012. Selection of an optimum truck and shovel fleet based on effective flat haul and capacity constraint modelling, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 19-26 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By P McCarthy

"This paper is based on 30 years of involvement in feasibility studies as a participant, study manager and the leader of a firm that provides study components and overall study management. The following topics are discussed:the purpose of feasibility studiesaligning the goals of the study team with those of the ownerthe difference between optimisation and designhow the types and levels of studies affect the organisation of the studythe relative merits of various management structures and contractual arrangementssetting scopes of work and tendering the work outthe selection of a study manager and the study management teamcommunications within the study team and externallythe project management trianglemanaging scope changes and maintaining flexibility to respond to study findingsprogress paymentsmanaging a study crisisinnovation, risk aversion and bankabilityreporting the resultsthe dangers and benefits of value engineering.CITATION:McCarthy, P, 2016. Making studies work – organisation, communication and management, in Proceedings Project Evaluation 2016, pp 20–30 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

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

The relationship between comminution testwork results and the milling circuit that is subsequently selected is not a direct one and frequently involves recourse to databases of past test results. This in itself reflects the lack of a systematic engineering approach in the design process. This paper reviews comminution tests for SAG mill design in an attempt to identify where the essential information comes from that will be used in mill selection. The conclusion is that results from traditional test methods, including obscure and little used procedures like the Mokken test, are more valuable from an engineering perspective than parameters for breakage rate based modelling. Suggestions are made on ways in which existing test procedures can be enhanced in order to generate parameters that can be directly related to characteristics of the milling circuit being designed.

Jan 1, 2002

By M Watts, P Lindsay

Herbert Stream, a tributary of the Waimangaroa River on the Stockton Plateau, has elevated metal concentrations and low pH characteristic of acid mine drainage (AMD). Dissolved aluminium concentrations average 8.3 ppm, iron 1.4 ppm, manganese 0.69 ppm, and zinc 0.12 ppm and pH ranges from 2.8 to 3.2. Flow rates range from 2.3 to 26.6 L/s with an average of 5.3 L/s. To determine the effectiveness of different treatment strategies, a small amount of the AMD was diverted through three small-scale passive AMD remediation systems over an eight month period. These included a reducing and alkalinity producing system (RAPS), a limestone leaching bed (LLB), and an open limestone channel (OLC). Both the RAPS and the LLB performed well, effectively removing metals and restoring pH. The RAPS lowered aluminium concentrations by up to 99%, iron 97%, manganese 95%, and zinc 80% and the LLB lowered aluminium concentrations by up to 99%, iron 99%, manganese 92%, and zinc 91%. The pH was restored to between 6.4 and 7.4 by the RAPS and to between 7.3 and 7.9 by the LLB. The OLC performed well as long as the residence time was similar to that of the other treatment systems. OLC removal rates for aluminium was up to 99%, iron 94%, and manganese 21%, and the pH was restored up to 5.6. Due to its simplicity and effectiveness, it is proposed the LLB be constructed to fullscale size to treat the entire Herbert Stream.

Jan 1, 2007

The Black Star lead and zinc ore-bodies, situated in the western zone of mineralisation at Mount Isa occupy an area 2000 ft. long with varying widths from 100 ft. to 300 ft. The strike is N5°W, and the average dip 60° West.To test at depth the potentialities of this area, an extensive diamond drilling campaign was commenced on 16th October 1927. It was continued, with from one to six machines working, until the end of 1931. During this period, 26 inclined holes, with an average depth of 1224 ft, and a total footage of 31,828 ft. were completed. A vertical hole, 2452 ft. deep, for comparative purposes, has been omitted.These drilling operations came directly under the charge of G J Gray, General Superintendent of Mount Isa Mines, and, in the early stages were supervised by E. D. McDermott, of the Mining Trust, London. The foremen, who were in charge of various sections of the drilling operations, were: H Vale, F Bray, J Winston and A A Sanstedt.

Jan 1, 1932

By C Zhang, P Wang, S Yao

The Zhilingtou Au-Ag deposit is situated in the eastern part of the complexly deformed and metamorphosed South China Caledonian Fold Belt. It consists of seven orebodies that are almost exclusively hosted by biotite plagioclase gneiss of the Precambrian Chencai Group. They form an apparent en echelon pattern in both cross-section and level plan. Three different ore types, based on mineralization textures, have been recognised within the Zhilingtou lode. These are Au-Ag-rich quartz veins, Au and Ag-bearing silicified rocks and Au-Ag-containing altered rocks with quartz stockworks. The mineralisation is principally composed of electrum, argentite, pyrite and minor sphalerite, galena as well as traces of hessite and chalcopyrite plus a gangue assemblage of quartz, rhodonite, sericite and chlorite. Fluid inclusions related to Au-Ag mineralisation yield a wide range of homogenisation temperatures from 110 to 447¦C, with two distinctive peak values at 250 - 300¦C and 350 - 400¦C respectively. d30Si values of quartz veins and silicification from the three stages of mineralisation range from -0.1 to -0.4ë. The mineralisation at Zhilingtou is interpreted as forming by recirculated meteoric water extracting ore-forming elements from metamorphic rocks due to Mesozoic volcano-magmatic activity.

Jan 1, 1995

By Y Shougu

Many mine accidents will affect the mine ventilation system when they occur. At present, there is a lack of monitoring means to capture the occurrence of accidents in time by monitoring the ventilation system, so as to take emergency measures to reduce the loss of personnel and property. Pressure wave is an elastic wave existing in air. Most accidents in mine will cause obvious changes of pressure wave. It is an innovative idea to monitor the occurrence of accidents in mine by measuring pressure wave. The development and functions of the pressure monitoring device and related software are introduced in detail. The pressure wave monitoring test is carried out in San Xavier underground mining laboratory, and the D-wave and S-wave waveform data are collected. The waveform characteristics are analysed, and the main frequency distribution of the pressure wave is found to be within 1 Hz by using FFT. At the same time, the influence of the propagation distance of the pressure wave on the waveform is analysed. The propagation velocity of D-wave and S-wave are roughly calculated, and they are 279.6 m/s and 397.3 m/s respectively. S-wave is slightly faster than D-wave. Although there are errors and uncertainties in the test, the test verified the feasibility of the existence and collection of pressure waves in the ventilation roadway, and provides a method for the future study of the propagation of pressure waves in the mine ventilation system.

Oct 12, 2022

By A Vickerfält, J Huss, J Martinsson

The European Union has listed vanadium (V) as one of the critical raw materials for the transition to a future green society, as stated in the Critical Raw Material Act, written by Grohol and Veeh (2023). In the steelmaking industry based on V-containing iron ore, V is a possible by-product from the slag. A requirement for slags to be suitable for V extraction is a V content preferably above 8 wt per cent as V2O3 and a phosphorus (P) content below 0.1 wt per cent as P2O5. Hence, it is important to keep V in the slag phase while the P is moved to the metal phase during the steelmaking process.

Aug 21, 2024

The Bradford Process, Australian Patent No. 11253, has had considerable application in the treatment plants of Broken Hill mining companies, and is at present being used by the North Broken Hill Limited for the treatment of weathered slime accumulations.The "Mining and Scientific Press," of 28th September, 1918, describes the Bradford Process at Broken Hill, specially featuring its application to slime material at the Proprietary mine-the home of the process.The points then stressed for galena flotation were acidulated slime pulp (0.025 to 0.030% H2S04) at temperature 85° to 90° F. and suitable time contact, with 1.5 to 2 lb. of sodium hyposulphite (per ton on slime) to permit the released S02 to "wet" or depressthe blende mineral. Also 1.0 to 1.3 lb. of crude sulphur (per ton on slime) was burnt, to supply S02 for keeping the lead concentrate clean during flotation. Pulp density varied from 23 to 26% solids. Since 1918 the process has been simplified in its application.Acidity of circuit, temperature, and sodium hyposulphite have been dispensed with, and now the S02 is practically all obtained by burning crude sulphur. I The plant units now employed for control and absorption of S02 gas constitute the main advance made in process, and these, with other details, are fully explained in this paper.APPLICATION AT BROKEN HILL NORTHThe existing North Broken Hill Limited gravity mill commenced operations on 9th September, 1909.

Jan 1, 1929

By Smith N. S, Rholl S. A, Otterness R. E

The Bureau of Mines is conducting research to develop blast designs for the control of fragmentation and rock displacement and the reduction of overall mining costs. This Bureau experiment, a program of 25 reduced-scale blasts conducted at the University of Missouri-Rolla's experimental quarry, determined the effects on fragmentation of changes in burden, spacing, explosive diameter, and stemming-explosive length. Combined with previous work at this experimental quarry examining air gap, delay, and decoupling effects, this experiment provided a data base of over 50 shots. The fragmented rock, 1000 to 3000 kg from each 3- to 4-hole blast in the 1 m bench of massive dolomite, was completely screened to assess fragmentation. The explosive used for all the tests was extra dynamite initiated by seismic caps fired from a sequential blasting machine with delays of 5.2- to 13-ms/m of burden. Empirical equations were developed which predicted the effect of shot design parameters on the fragmentation. These formulas predicted the average fragment size of each of the 25-shots to within 13 percent. For spacing to burden ratios of 1, 1.4 and 2, there were optimum burden to explosive diameter ratios (B/de) of 30, 26 and 20, respectively. Decreasing the B/d. ratio beyond these levels resulted in little or no reduction in the average size. For B/de ratios above these levels the average size increased but, at least a 15 percent reduction in the average size results when the shot design parameters are optimized.

Jan 1, 1990

By M Maguire

The purpose of this paper is to provide an illustration of the Resource Management Act processes at their best. Many of you will be aware of the Martha Mine situated in the middle of Waihi Township in Hauraki District. Underground mining ceased on Martha Hill in the 1950s. A new mining licence was issued in the late 1980s and since that date open cast mining has continued at the site. The Hauraki District Council notified its proposed plan in October 1994. Prior to that date numerous discussion papers and draft sections of the plan had been disseminated in the community. Considerable consultation was undertaken with all interest groups. As an indication of the success of that consultation process only 17 references to the Environment Court were lodged following the making of decisions on submissions and further submissions. Those references, which included a number from the Minerals Industry, were all resolved by consent. Out of the reference and consent order process EMMA (Extended Martha Mineral Area) was born.

Jan 1, 1998

Since early-2001, Kalgoorlie Consolidated Gold Mines (KCGM) has successfully operated an ultra fine grinding (UFG) circuit to supplement its roaster capacity for the treatment of the refractory gold flotation concentrate. A second UFG mill was installed in 2002 taking the total UFG capacity to over 20 tph while grinding to 11 to 12 microns and achieving over 90 per cent gold recovery. A development program in 2002/3 involving plant trials, pilot plants and laboratory testwork resulted in process improvements and a better understanding of the milling and gold leach processes that assisted in narrowing the gap between UFG and roasting. This paper details the operation of the ultra fine grinding process at KCGM as a non oxidative treatment for the extraction of gold from a refractory ores.

Jan 1, 2003

Radio Detection and Ranging is an active form of remote sensing. The-imaging system sends out a source of electromagnetic energy to 'illuminate' the terrain and then records the energy returned. The wavelengths used by radar are in the microwave region and vary from a few millimetres to about a metre. Radar systems are independent of lighting conditions and weather. In addition, targets may be illuminated in the optimum direction to enhance features of interest. New Zealand was one of the principal investigators on the Shuttle Imaging Radar (SIR-B) experiment, part of the payload on Challenger Mission 41-G in October 1984. Data collected over New Zealand was restricted to two very poor quality optical images and one poor quality digital data take. The digital image covered the ranges between the Hawke Bay-Wairoa Basin and the Volcanic Plateau. Variations of texture in this image frequently were indicative of variations in lithology and induration. The image also clearly depicted major faults where these had had a significant effect on the topography.

Jan 1, 1986