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The excavatability of the rock mass in a proposed open pit mine at Globe-Progress has been assessed. The rock mass was initially evaluated by determining variations in seismic velocity and by using the Revised Size-Strength Chart. These two assessments should be performed during the feasibility or early investigation stages of a project. A complete rock mass excavatability assessment using a suite of geological and geotechnical properties was then performed using three methods: RMR System; Modified Rippability Rating; and a productivity estimation method. These three methods should be applied during the investigation and design stages of a project. The preliminary assessments show that most of the open pit rock mass is expected to be rippable. The complete assessment differentiates weak, fair and good rock masses within the open pit. Weak rock mass exists along the Globe-Progress Shear zone, located along the northern and eastern pit walls and also in the western pit wall where the Chemist Shop Fault is located are both regions are expected to be diggable. Relatively weak rock mass also exists along the Globe-Progress Shear axial hinge. The Globe-Progress Shear limbs are generally fair to good rock where moderate to hard ripping should be expected.

Jan 1, 1996

By M E. Taulis, S Hayton, D A. Manhire, J G. Pope

Successful development of coal seam gas (CSG) resources in low-rank coalfields such as the Powder River Basin has raised interest in CSG from low rank coal in New Zealand. Kenham Holdings Limited holds 12 Petroleum Exploration Permits (PEP) covering some of New ZealandÆs low-rank coal and lignite resources and has engaged CRL Energy Limited to assist in the systematic evaluation of the CSG potential of the permits. To date, exploration results from seven New Zealand coalfields reflect differences in coal type, rank, depositional environment and depth of burial between coalfields. Several of the explored coalfields are considered prospective for CSG. One of the most advanced Kenham exploration programmes is in the Hawkdun Coalfield, Central Otago.   The Hawkdun Coalfield contains a single, thick lignite seam with properties that are similar to the Powder River Basin. Preliminary results indicate the Hawkdun Coalfield is prospective for CSG with the potential to contain between 25 and 60 PJ of gas; enough to supply a 30MW power station for ten to 25 years. Further drilling is planned to investigate the economic viability of the Hawkdun Coalfield. The in situ permeability of the lignite, the amount and availability of free gas, gas saturation at depth and market opportunities will determine its economic viability. If initial pumping and production results in the planned exploration programme are promising, the Hawkdun Coalfield will be further developed with additional production drillholes to form a trial production pod.

Jan 1, 2004

CONTENTSIntroductionNorthern ExplorationDrive ConceptionGeneralDriving CrewDrive Cross Section and Track DetailsVentilation by Electrically Driven FanTemperatures and HumidityFan PerformanceRock Drill Carriage and Rock DrillsStandard Drilling RoundElectric Firing from Power MainsExplosives and DetonatorsCharging and FiringMechanical Loading and Electric HaulageOperating CycleStatisticalEquipmentAcknowledgementINTRODUCTION.The driving project described in :this paper is one of greater magnitude than usual for the Broken Hill field, and in the execution of the work a departure was made from long-established local practice by the introduction of mechanisation. The primary object of the drive is to provide sites for gaining information regarding the behaviour of the ore-bodies well beyond the limits of the present exposures.Due to thermal conditions, the major portion of the work was done on a six-hour shift basis, in contrast to the normal one of seven hours, with a five-day week.

Jan 1, 1946

By J R. Goff, R Carver, D S. Sheppard

The REGCHEM (Regional Exploration Geochemistry) stream sediment geochemistry database of open file mining company data, managed by GNS Science, was recently made accessible via the internet (http://maps.gns.cri.nz/website/minmap/). REGCHEM provides coverage of selected elements in mineral rich areas of New Zealand. Analysis of REGCHEM data highlights problems with inconsistencies between different surveys in terms of sampling methods, number and types of elements analysed, analytical techniques and detection limits. New, consistent multi-element geochemical surveys with national coverage are required. To test sampling, analytical and data treatment techniques for the new surveys, a pilot stream sediment geochemical survey was carried out in the Thames area, Hauraki Goldfield. Seventy samples were collected in an area of 220 km2 representing about one sample every 3 km2. The samples were analysed for 50 elements, mostly by XRF.   Regional patterns are apparent in the concentrations of some elements. Several elements, such as As, Cd, Cu, K, Pb, Sb, Se, and Zn exhibit anomalous concentrations mainly in the western part of the study area, related to Au-Ag-Zn-Pb-Cu epithermal quartz veins and porphyry Cu occurrences in hydrothermally altered andesitic terrane.   Mercury is anomalous in southern samples, reflecting cinnabar occurrences in the Kauaeranga valley (eg Mangakirikiri), and the occurrence of cinnabar as a late stage mineral in some of the Thames epithermal veins. Ba and U are anomalous in the eastern samples, and these anomalies are probably related to the presence of rhyolitic rocks in the eastern part of the project area.

Jan 1, 2006

By S M. Loewen, J J. Fuykschot

Located in the north-west of Kazakhstan is a world-class podiform chromite deposit. Donskoy mining and beneficiation complex (DGOK), a branch of Kazchrome TNC, which is a subsidiary of the Eurasian Resources Group (ERG) operates two underground mines in this area, one of which is the ‘10th Anniversary of Kazakhstan Independence’ (DNK) mine.The mine currently applies the gravity caving mining method, producing 1.8 Mt/a of ore utilising a slusher layout and rail transport to the hoisting shafts. The deeper zones form the largest mineral resources at the DNK mine and are planned to be developed in the next several years. At this depth, the generally poor ground conditions, combined with the high in situ stress state will potentially lead to extremely challenging mining conditions.This paper describes a technical study undertaken by SRK to determine the possibility of increasing the maximum production rate from the currently envisaged 6.0 Mt/a to 7.2 Mt/a, and to reduce the time taken to steady state production.Based on a newly created 3D model, the inclined caving method was proposed for the largest orebodies. This method, presently not implemented at any operating mine, although planned for two other projects, was deemed very suitable to deal with the weak rock mass characteristics and the plunging morphology of the mineralisation.Dassault Systèmes’ GEOVIA’s Footprint Finder software (a module of GEOVIA’s PCBC™) was used to determine the caving zones and production schedules. The total mine design was completed in Deswik software, and resulting schedules combined in Excel.In addition to the use of an inclined caving method, several other suggestions were made to increase the productivity of the mine, such as the application of a conveyor belt system transporting multiple material types, teleremote technologies and the application of thin sprayed liners to reduce the swelling of the rock mass.CITATION:Fuykschot, J J and Loewen, S M, 2016. Inclined caving option for the DNK mine, Kazakhstan, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 669–682 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

This paper deals with the application of table flotation to two unusual mineral dressing problems. Both problems involved the removal of interfering minerals at sizes too coarse to normal froth flotation.The first problem was the removal of arsenical minerals from Broken Hill gravity concentrates without further size reduction. Table flotation without grinding of the original concentrates gave almost complete rejection of the arsenic from the concentrates. A typical test result was a reduction of arsenic in jig concentrate from 0.75% arsenic to 0.007% arsenic.The second problem was to develop a method to produce a high grade calcium carbonate concentrate from coastal dune sands containing about 10% silica and about 80% calcium carbonate. The sands were about 30 mesh British Standard Screen (B.S.S.), and for economic and other reasons it was stipulated that the separation be made without grinding. Again, table flotation gave excellent results. A concentrate was produced containing 99.62% acid soluble material, representing a recovery of 98.69% of the calcium carbonate in the feed with a rejection of 96.44% of the silica.The investigations' were carried out at the Kalgoorlie Metallurgical Laboratory, under the Department of Mines...

Jan 1, 1954

By D Brett

"Mine waste storages including tailings dams and waste rock dumps represent arguably the biggest risk on a mine site from both physical and geochemical viewpoints, related firstly to structural stability and the consequences of failure and secondly from potential on-going seepage or run-off of acid and metalliferous drainage (AMD). The risks are most likely to increase during operations and continue through the closure and post-closure phases, with the waste storages likely to be the most difficult features to resolve in the mine closure process. Contaminated water quality from tailings dams and waste rock dumps can require treatment "in perpetuity" at a cost of hundreds of millions of dollars. The problem is increasing with ever larger mine operations and waste generation volumes. This paper identifies leading practice methodologies in planning and operating mines and process plants to minimise the risks from tailings storages and how this might also affect waste rock management and even the design of mine excavations. These methodologies require a "big-picture" approach to develop an understanding of the overall issues and identify synergies between the different operational areas on a mine site that can reduce overall risk. With a conservative approach and realistic allowance for future costs it is possible to facilitate decisions at the mine planning stage that can reduce risk and save cost over the long term. This is in contrast to the common approach where each operational area is looking to minimise its own costs with a short-term view. Incorrect mine methodologies can be developed by allowing net present value (NPV) accounting methods to trivialise future closure issues.Methodologies discussed include: Integrated Waste Management - Significant structural improvements to tailings dams can be achieved if the structures can be incorporated into the waste rock dumps. Risk of AMD can also be reduced by utilising the tailings and waste rock effectively. This could go even further to consider the placement of wastes to limit mine void environmental issues; Process Optimisation - Water quality and the nature of potential tailings dam structures can be highly influenced by the geo-chemistry of the tailings. This can be modified by processing, where simple changes such as maintaining separate streams of geo-chemically different tailings rather than recombining them or by initiating further processing to remove problematic minerals such as sulphides; Enhancing Geophysical Properties - The geochemical performance of waste repositories can be greatly influenced by the geophysical properties of the stored materials, particularly the air-water characteristics, which are influenced by particle size, density and permeability. The geotechnical properties can be enhanced by strategic paddock dumping, blending and compaction.These methodologies are demonstrated by case histories.CITATION:Brett, D, 2013. Mine waste risk minimisation by integrated waste management and process optimisation, in Proceedings MetPlant 2013, pp 247-258 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

By L Reynolds

Oceana Gold (New Zealand) Limited (OceanaGold) has commenced mining operations at the Globe-Progress mine in the Reefton Goldfield, an area that historically produced 2.1 million ounces of gold from underground quartz lode deposits. During the construction phase of the operation, advanced exploration programmes targeting near-mine prospects commenced. The focus of this ongoing exploration is the discovery of near surface, refractory gold deposits that are amenable to open-pit mining methods and treatment through the Globe-Progress process plant.   One such discovery is the Supreme deposit, located along strike approximately 3 kilometres to the south of the Globe-Progress mine. The Supreme area was tested extensively with diamond drilling in 2006, defining a deposit with similar mineralisation styles and grade to the Globe-Progress deposit. The mineralisation comprises a central core of gold-bearing quartz veins, locally containing visible gold, surrounded by a more extensive halo of refractory, disseminated gold associated with an arsenopyrite-pyrite sulphide mineral assemblage. Three subparallel mineralised structures host the mineralisation. These structures are highly oblique to the country rock orientations, extending approximately 250 metres along a northeast-southwest strike and at least 220 metres down-dip, with an average thickness of 12 metres and moderate dip to the southeast. Records of historical workings indicate that mineralisation extends further down-dip and remains open at depth. 5175 ounces of gold were mined historically at the Supreme deposit. OceanaGold have defined an Inferred Resource for the Supreme deposit of 0.84 million tonnes at 1.46 grams per tonne for a total of 40 000 ounces (at a 0.8 grams per tonne cut-off). Higher-grade zones of mineralisation exist within the deposit and further drilling is planned to test the extent, continuity and geological controls of the mineralised structures.

Jan 1, 2007

By A G. Mitchell

Stream sediment geochemical analyses were collated from open-file mining company reports and assembled in the REGCHEM computerised database at the Institute of Geological and Nuclear Sciences Limited. The database operates on an IBM-compatible PC microcomputer using an application programmed in dBASE IV and termed GEOEXPL. By August 1992, data for 6383 stream sediment samples from 6335 different sites in the Coromandel Peninsula region (Hauraki Goldfield) were entered, giving a total of 29 292 separate elemental analyses. Preliminary statistical analysis using PROBPLOT on a set of data collected by AMOCO from the Mahakirau-Whangapoua area shows that these data are a complex mix of subpopulations related to mineralisation and different source rock types. Thresholds of 37 ppm copper, 31 ppm lead, 112 ppm zinc, and 2.3 ppm molybdenum, defmed by arithmetic models for the combined data set, separate the individual element sets into 'first order anomalous/lesser anomalous and background' subpopulations as follows: copper five per cent/95 per cent, lead five per cent/95 per cent, zinc one per cent/99 per cent, and molybdenum 15 per cent/85 per cent.

Jan 1, 1992

The Effect of Bulk Iron Concentration on the Copper Activation of Sphalerite at pH 9

Sep 13, 2010

Last evening, in Auckland, I heard the Chairman of Heinz US, Dr Tony O'Reilly (who, in addition to Heinz's ownership of our largest food processor, also has substantial personal investments in this country), advocate New Zealand as a 'regional corporate capital'.   Why would someone like Dr O'Reilly hold that view? No doubt, as one of Ireland's great rugby players of the 50s and 60s, he admires at least one thing that we do very well (confirmed again in Dublin over the past weekend). But that's not sufficient to support such a view.   He cited many reasons for preferring New Zealand over, say, Sydney, Australia, calling this 'the most rational in which to locate [an] international headquarters', including û +         we have no capital gains tax; +         a more 'pro-business environment'; +         a 'first class' legal and banking system; and +         a 'simple political system'.   I can find no better 'text for today's address.

Jan 1, 1997

The 8 ft by 91/2 ft drive which joined No. 7 Shaft with Browne Shaft on the 1,480 ft level was extended from both ends and met at a point approximately 12,000 ft from No. 7 (2,000 ft from Browne).The surveying required for this 2 1/2 mile haulage drive called for greater accuracy than was obtainable from South Mine standard methods. Procedures and devices from published information were tried and modified as required to suit local conditions. Several new methods were applied and improved as the drive advanced. The control of angular, linear and level measurements was perhaps considerably in excess of the requirements, but this was offset by abnormally large discrepancies resulting from shaft plumbing. The accuracy of the final breakthrough, although not to the standard desired, was sufficient to complete the connection without inconvenience and added cost.INTRODUCTIONThe acquisition of the Browne Shaft leases in January 1962 presented the management of Broken Hill South Limited with the problem of transporting ore from these leases to its mill. It was eventually decided that diesel locomotivehaulage through a 2t mile drive on the 1,480 ft level between the two mines was the best solution. The drive was advanced from both ends after Browne Shaft was deepened by 80 ft to reach the 1,480 ft level horizon. Each end advancedabout 15 ft/day with the miners working three 7 hr shifts. Blasting was restricted to the end of the shift.The survey work involved five shaft plumbings and 78 theodolite stations in a traverse, underground and surface,of more than 5 miles. Because of the exceptional length of the drive, an unusually high degree of reliability was required.The aim was for a maximum error at breakthrough of 1 ft 1 in 30,000, and to secure this, precise methods of linear measurement were necessary. Shaft plumbing in particular posed special difficulties.

Jan 1, 1965

For small particles of niekel flotation eoncentrate (av. size 50 pm) the predominant heat transfer mechanism under suspension smelting conditions, prior to ignition, is conduction from the gas and not radiation from nearby hot bodies. Results of laboratory tests using gas temperatures 380-700°C and furnace wall temperatures 380-1100°C were in accord with heat transfer theory. In practieal flash smelters earlier ignition, and hence better utilization of the space in the shaft, would result from introduetion at the top of the shaft of gases hotter than the ignition temperature of 500-600°C.

Jan 1, 1979

By A Parbhakar-Fox, B G. Lottermoser

Management of solid mine wastes, particularly waste rock, requires careful planning to reduce the likelihood of sulfide oxidation, and generation of acid rock drainage (ARD). Waste management strategies must focus on obtaining a thorough understanding of the environmental characteristics of future waste rock materials. In this study, a waste management strategy for characterising underground waste rock was developed at a polymetallic underground mine in western Tasmania to determine which materials were appropriate for surficial placement. The criteria for surficial placement set by the regulator were that materials had to be non-acid forming and non-metalliferous. A range of cost-effective field-based tools, mineralogical assessments and mineral chemistry techniques were used on a suite of representative drill core material to determine an appropriate waste management strategy. Ultimately, a modified geochemistry–mineralogy–texture–geometallurgy (GMTG) approach was designed, whereby geoenvironmental focused logging and simple prescreening tools such as paste pH and sulfur analyses were used at stage-one; routine acid base accounting and leachate tests at stage-two; and validation tools including X-ray diffractometry and laser ablation inductively coupled plasma-mass spectrometry (ICPMS) at stage-three. This approach should be considered for other mine sites at early and operational life-of-mine stages with similar deposit characteristics, to ensure correct screening and placement of potentially hazardous waste materials in suitable above-ground waste repositories or mined-out mine sections.CITATION:Parbhakar-Fox, A and Lottermoser, B G, 2017. Effectively linking mining geology with waste management – a case study from western Tasmania, in Proceedings Tenth International Mining Geology Conference 2017, pp 117–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Previous methods for measuring the flow of solids in Jnrdraulic conveying have not considered the important effects of slip velocity and particle concentration. In this paper an extension of the method proposed byShirato et al. (J. Chem. Engng. 'Japan, 1: 164-167) for determining mass flow in a vertical conduit is outlined.The present method consists of measuring' the volumetric flow of the slurry (by a magnetic flow meter for instance) and the density of the slurry in two pipe sections of different diameters. Effects of variation of slip withparticle concentration, not previously considered, are allowed.Problems involved in estimating the density of a slurry from differential pressure measurement are discussed.The major problem is the uncertainties in estimating frictional losses due to the wall in two-phase flows. The greater reliability of a more "direct" technique, such as by 'Y-ray absorption, for measuring solid concentration is emphasized.

Jan 1, 1971

IN 1906, soon after his arrival in New Zealand, a brief article was prepared by the writer on "The Salient Features of the Economic Geology of New Zealand," for the Journal of Economic Geology. In November, 1907, a somewhat similar paper, entitled "The Mineral Wealth of New Zealand," was read at the Royal Colonial Institute in London. The present contribution to the Transactions...

Jan 1, 1909

The Mahakipawa gold deposit is located 21 km northwest of Blenheim. It became the site of a small hardrock gold rush in 1889 following nearby alluvial gold discoveries in 1888. The study investigates the geology of the area of hard rock mining in the vicinity between Cullens and Waikakaho Creeks. The Marlborough Schist which hosts the gold depos, it consists of polydeformed greenschist facies quartzofeldspathic psammitic, pelitic and volcanigenic schist.

Jan 1, 1993

The labour question is one that has caused mine managers much thought and anxiety and is likely to continue to do so as long as human beings exist. The difficulty is to devise some arrangement whereby the interests of miner and mine ownerare identical. Mines cannot be worked without capital, and capital is no good without labour, yet, though both have the mine in common, their interests are not exactly the same. Some men are happy so long as they can scrape through by exerting themselves as little as possible, but capitalists do not work mines for charity, they want some return for their money.Where a large number of men are employed there are bound to be examples of all sorts, good and bad, and it is because one cannot depend on all, that different methods of employment have to be adopted. Which method is selected depends to a great extent on the labour market, local conditions, nature of the ore and the way in which it occurs.A big step towards success is obtained by securing the services of good bosses, not only those who know how work should be done, but men who have a knowledge of human nature. It is a big mistake to be too lenient with a man, also to be unnecessarily harsh. A good boss will always be sought out by good men who have worked under him before, or who have heard of him from others. By a good boss we do not mean one who employs two men where one would do, or who lets the men loaf...

Jan 1, 1901

By G B. Arehart

The Midas epithermal system is one of the larger low-sulfidation epithermal vein systems discovered in the western US in recent years, containing in excess of 3 Moz of gold (premining). The deposit is spatially and temporally related to bimodal volcanism in the Northern Nevada Rift; dates on igneous rocks (16 - 14.7 Ma) bracket the age of high grade veins (15.3 Ma). Hydrothermal alteration at Midas is typical of epithermal systems, comprising proximal potassic through distal propylitic assemblages; in contrast to many epithermal systems, Midas has minimal development of wallrock illite/sericite. Mineral assemblages are clearly zoned on the vein structures that acted as focal planes for fluid upflow. Geochemical zoning patterns also show this zoning. Metals were deposited in open-space veins as the result of boiling of hydrothermal fluids; multiple episodes of crustiform mineral deposition are documented in the vein textures. The major vein minerals include quartz, adularia, calcite, selenides and sulfides, with electrum as the primary ore mineral. REE patterns for vein material are similar to patterns for coeval rhyolites, but distinctly different from patterns of the host rocks. Stable isotope data are consistent with meteoric water as the dominant ore fluid. Combined REE and stable isotope data suggest that fluid from which the main ore-bearing stage of the veins was deposited was slightly lower pH than other stages.

Jan 1, 2005

Simulation and Analysis of Media Behaviour in the Tower Mill by Discrete Element Method for Estimating the Power Draw and Spatial Distribution of Grinding Process The trends to the Tower Mill (TM) for grinding the materials are increased recently due to its unique merits. Among the various considerations of this machine, the main important items are increasing the efficiency of grinding as more as possible while keep the power consumption, manufacturing and maintenance costs as less as possible. Because this grinding process includes a huge numbers of media particles (ball or other shapes) that are interacted with each other and body of the machine, the DEM (Discrete Element Method) way is a very useful and essential step to getting confident evaluations. Because the DEM simulation is a very young scientific field and proper commercial software are very rare and still under modification, at first step, a FORTRAN code is developed for DEM simulation of two laboratory Tower Mill models (KM5 and KD5). The simulation and experimental results matched each other properly. Then one another DEM software was implemented to perform simulation of bigger models (huge numbers of balls), meanwhile could handle the complex 3D geometry data. The simulation and experimental results were compared and analysed in detail for not only laboratory but also for industrial models (KW5, KWD5, KWD50, KW300F, KW700F and KW1500) without any manipulation or compromising of the parameters of simulation. Some numeric data of industrial models are hidden here due to confidential reasons. The relative velocity of balls (ball-ball and ball-TM body), dissipate energy, interacted forces and stresses during the process are the key outputs of DEM simulation for design this machine. Therefore the main important processes in a Tower Mill machine are recognised and consequently some horizons of development of this machine are distinguished.

Sep 13, 2010