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By H Kurth, L Balzan

On-belt analysers have been used since the early 1980s in the coal sector to measure ash content in real time for diverting material on conveyors to remove waste, bypass beneficiation and allow suitable material to proceed to the wash plant for processing. Since 2008, a GEOSCAN-M elemental analyser has been used on an overland conveyor in South Africa to divert direct-shipping quality iron ore to bypass a jig plant. This paper focusses on recent evaluation work to determine the suitability of an on-belt analyser to upgrade the processing plant feed in a copper-gold operation.Copper-gold ore samples from New Gold’s New Afton Mine near Kamloops, BC, Canada were tested to assess measurement accuracy over short time increments. A two-minute measurement increment has been used in the minerals sector as a compromise between good measurement accuracy and a useful tonnage (haul truck equivalent size or smaller). At New Afton, this increment represents approximately 35 t of material. Segregation decisions are currently made after visual and sometimes analytical determination, at increments of approximately 500 t to designate material as ore or waste at the drawbell in the cave.Results of test work including the composition range and expected accuracies by element are shown. The operation, which is not mine constrained, was evaluating the potential for ore upgrading through waste and low grade increment diversion to upgrade ore quality feeding the mill. Prompt-gamma neutron activation analysis (PGNAA) was considered as the company recognised that it would measure through the full conveyed cross section continuously and produce multi-elemental measurements unaffected by particle size, dust, moisture content, layering and segregation, mineralogy and belt speed.GEOSCAN analyses over various analysis periods will be collected to identify variability in the conveyed material quality and used to generate tonnage-grade curves so that an optimal diversion (bulk sorting) tonnage increment can be determined. Measurement increment time can be customised to suit site requirements. CITATION:Kurth, H and Balzan, L, 2017. Assessing bulk sorting suitability at the New Afton mine, in Proceedings MetPlant 2017, pp 315–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Several Approaches to Enhance the Bioleaching of Enargite Some approaches were investigated to enhance the recovery of Cu from enargite by bioleaching with Acidithiobacillus ferrooxidans using the galvanic interaction with pyrite and activated carbon, and with thermophilic bacteria, Acidianus brierleyi. Addition of pyrite initially enhanced Cu leaching by the Galvanic effect, but after that the formation of secondary minerals passivated the surface of enargite in inoculated batches. Activated carbon improved Cu recovery from enargite much better than pyrite, when it is contacted with enargite. Recovery of Cu from enargite has been recorded to at largest 2.4 per cent within 30 days in the presence of activated carbon when mesophilic bacteria were inoculated at 25¦C. The recovery of Cu from enargite was drastically enhanced by inoculation of thermophilic bacteria, Acidianus brierleyi, up to 60 per cent within 40 days at 70¦C and still not leveled off after 40 days unless the formation of Fe(III) precipitates occurred. After 40 days dissolved molar ratio of Cu/As is around 5.2, suggesting that metal-deficient sulfides and/or ferric arsenate might be formed on the surface of enargite.

Sep 13, 2010

By Sneddon N

In November, 1975, Aberdare North colliery was sealed at the surface to extinguish an open fire underground.The fire had developed from a spontaneous heating in one of the open goaf areas of the mine.The mine was re-entered with normal ventilation methods following the isolation of the working district containing the fire. The isolation was accomplished by remotely sealing the open roadways with lly ash emplaced through boreholes from the surface. A subsequent re-entry operation similarly closed the roadways close to the fire and enabled the re-opening of the sealed district.Most of the mine and the underground equipment was recovered after clearing of numerous falls and production recommenced on 25th October, 1976.

Jan 1, 1978

By Elford H. S

Mr. H. W. GEPP said he desired to bring particular attention to this paper. The underlying intention of the Development and Migration Commission when the paper was prepared was to place at the disposal of Australian miners and metallurgists the story of the development of tin metallurgy as it had been advanced in other countries, particularly Great Britain. They had very considerable resources of low-grade tin-bearing metals in the eastern coast of Australia particularly, and they need not anticipate that tin was going to remain at the extremely low price at which they saw it to-day. The Commission felt that it was most desirable to place 'on record, and make easily available, the story of the treatment of comparatively low-grade tin ores in other parts of the world.Arrangements were made that the technical staff at Australia House, in conjunction with Mr. H. S. Elford; should collect this information so that in due course, when Australia awoke to an interest in low-grade deposits, of which there were many throughout Australia, this story would then not,have to be gathered from other areas and other places of the world. The -paper was a contribution which would turn out to be of very great value. He suggested to the younger members that this thorough contribution could be made the subject of study so that they would be ready to assist in the developments which must come. Mr. WM. APLIN said there was one point in connection with the paper upon which he would like to speak. While at Mount Morgan he had occasion to test some highly pyritic tin ore by flotation, with a view to separating the cassiterite from the pyritic mineral.Instead of accomplishing that, it was discovered that it would be possible to eliminate as much as 50% of the total weight of ore in the form of a pyritic flotation concentrate, which would contain...

Jan 1, 1930

The mineral matter has been isolated from a selection of Australian bituminous coals using low temperature (radio-frequency) oxidation or hydrogen peroxidation techniques and the species present identified by x-raydiffraction. Quartz, kaolinite, and a range of mixed layer clay minerals are the dominant constituents of the coals studied, with carbonate, sulphate, and phosphate minerals abundant in some samples. The clay bands thatoccur within these coal seams contain similar mineral assemblages to the coals themselves, but the lutites that form the inter-seam strata have a markedly different mineralogy, characterized by abundant quartz andillite and a low kaolinite content.The kaolinite is thought to have formed chiefly by interaction of silica and alumina in the waters of the coal swamp, aided by the catalytic action of organic acids, while most of the other clay minerals are probablydetrital. The absence of illite from Australian coals is not fully understood, but it may reflect the action of organic acids on the detritus in the swamp, coupled with deposition in freshwater rather thanmarine conditions. Pyrite, although present in some coal samples when fresh, may undergo oxidation during storage to form a number of sulphate minerals, some of which may interact with any calcite present toform gypsum.The mineral matter assemblage in the coal determines to a great extent the fusion characteristics of the ash.Unless abundant carbonates are present, coals with kaolinite-rich assemblages have a very refractory ash, while those rich in chlorite or montmorillonite have ash fusion temperatures between 1000 and 1300°C. Theinfluence of the minerals on coal preparation and coking properties is also brieflY discussed, as well as the potential of mineral matter studies in coal seam correlation.

Jan 1, 1978

Upgrading and Removing Phosphorus from Low-Grade and High Phosphorus Containing Iron Ores

Sep 13, 2010

An important consideration in any mining operation is waste disposal management. Tailings management at Macraes gold mine allows for the disposal of tailings into fully engineered embankment dams and overburden material to be incorporated as construction material into those embankment dams. This paper outlines the current tailings management practices.

Jan 1, 1992

Mining is a fundamental activity on which modern society and the world's economy are entirely dependent. Mining investors, large and small, invest on an international scale, frequently being active in several countries.   Prior to committing investment to new countries, the prudent investor will consider the risk involved by analysing a number of physical, financial, administrative and political parameters that impact on the potential financial returns it is seeking. This paper considers these risk factors in relationship to New Zealand and six competitor countries. The conclusion is that for reasons largely within the control of our politicians, New Zealand is a high risk country for mining investors.

Jan 1, 1993

With the change in legislation under the Resource Management Act 1991 (RMA), the responsibility for administering the effects of blasting on the environment, has transferred from an essentially central government system to local bodies. This naturally will allow for a variety of compliance levels and control procedures which will depend on the particular local body and rather ad hoc arrangements. It is anticipated that the existing NZ Standard on blast vibration levels will soon be replaced by the Australian Standard. These changes raise the question as to what should be used as suitable compliance levels to prevent damage to structures. The paper will address the measurement, control levels and the appropriateness of current standards in relation to the overall legal framework of the RMA.

Jan 1, 1996

Few, if any, reliable thermodynamic data are available for the activity of tin oxide in slags. In this work, the activity of the oxide in silica saturated iron silicate slags has been measured at 1573 K using the equilibrium Sn (alloy) + Y2O2-SnO (slag).Slag and a Ag-Sn alloy were sealed in a zirconium oxide crucible to prevent the escape of volatile tin oxide, and the oxygen pressure at equilibrium measured in situ using the zirconium oxide as a solid electrolyte. Activity of tin was calculated from known data for the Ag-Sn system and activity of tin oxide calculated from free energy data. The results have been extrapolated to predict the industrially important distribution of tin and iron between Fe-Sn alloy and iron silicate based slags.

Jan 1, 1983

By J S. Dunlop

At its most basic level, minerals project management may be broken down into a series of logical chronological phases, described in this paper as: exploration, discovery; scoping and pre-feasibility; feasibility and approval; project financing and commissioning; operation; expansion and closure. Each phase has its own peculiarities and challenges, any one of which can potentially upset the forward progress of a minerals project.Reference is made to each of these project phases based on the authorÆs many years of first-hand experience, in an attempt to identify issues within the project management spectrum where additional caution may be warranted. Left un-addressed, these issues can cause undue delays in the project timeline, ultimately delaying approval at significant project cost.Finally, reference is made to the Mine ManagerÆs Handbook recently published by the AusIMM which is an excellent project management resource, considered to be very relevant for minerals treatment plant managers, whether the context be constructing, operating, expanding or shutting down.CITATION:Dunlop, J S, 2013. Mineral project management - A perspective from four decades in the industry, in Proceedings MetPlant 2013 , pp 13-27 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By D A. McCallum

With depth, many gold ores become sulfidic with minerals such as pyrite, pyrrhotite and arsenopyrite becoming prevalent. In addition, many underground gold mines use tailings backfill to bind and store the waste. In these cases, acid mine drainage (AMD) can become an issue. One approach to the control of AMD is desulfurisation whereby the sulfide minerals are removed prior to disposal. Four sulfide tailings samples, representing different ore types and gold and base metal operations, were selected for assessment and testing using simple physical beneficiation techniques. The aim was to determine the extent to which mineral processing methods were suitable for separating sulfides from non-sulfides and for extracting potentially marketable by-products from the tailings. In order to streamline the testing procedure a simple diagnostic separation technique was developed to enable quick screening of bulk sulfide tailings for suitability for reprocessing. The testing procedure involved detailed characterisation and a sequential set of testing regimes based on simple unit processes including water washing, classification, gravity concentration, magnetic separation and bulk flotation. The preliminary test results indicate each unit process can play an important part in producing effective sulfide/non-sulfide separations and in generating useful by-products from the tailings. Potential valuable products identified include coarse, benign silica sands, bulk iron sulfide products rich in pyrite and/or pyrrhotite, high-grade iron products (magnetite) low in silica, low-volume bulk sulfide concentrates and low-grade molybdenite and talc products. The work presented shows how sulfide tailings can be viewed as a resource rather than a waste stream, and identifies a pathway for developing a more sustainable approach to the environmental management of sulfide tailings for the future.

Jan 1, 2007

In, one stage of the purification sequence of the zinc sulphate electrolyte used at Risdon, cobalt is, precipitated as cobalt nitroso-,B-naphtholate, which is separated from the solution by filtration. Owing to the method of conducting the purification the filter cake contains much gypsum, unconsumed calcium hydroxide, basic zinc sulphate, and entrained zinc sulphate solution, Small amounts of iron and copper that have escaped previous purification steps are also precipitated with the cobalt as nitroso-,B-naphtholate. Thisprecipitate, normally carrying about 18% cobalt, is the raw material for the production of cobalt oxide, cobalt sulphate and cobalt metal.COBALT OXIDEThe main problem in the preparation of a reasonable grade of cobalt oxide from the filter cake is the economic separation ,of the cobalt nitroso-,B-naphtholate from the gypsum. This was solved by the application of flotation. It was discovered that the cobalt nitroso-,B-naphtholate, under correct conditions, would float without any addition agent, giving a relatively high grade concentrate. A plant, was built and has been in operation since 1936. The filter cake is pulped with water and pumped to one of two mechanically agitated tanks, eath capable of holding one day's output. Sulphuric acid is added until the free acid concentration reaches about 3 gm. per litre. Basic zinc sulphate is dissolved and calcium hydroxide converted to gypsum. The pulp, carrying about 2t lb. of solids per gallon, is pumped at a suitable rate to the first of a series of 10 flotation, boxes.. Each box is 3 ft. by 2 ft. 9 in. by 5 ft. deep, and, all have a common, pulp level, since the...

Jan 1, 1949

The achievement of high availability of the Grey River Gold Mining Limited's alluvial gold dredge is a tortuous task which will rely upon the dedication of all staff employed at Grey River Gold Mining Limited (GRGML). The persistent adoption of new technology and better operating procedures, combined with a strong commitment to preventative and predictive maintenance, is necessary. The Grey River Gold Mining Limited alluvial gold dredge is operating in a relatively low grade alluvial gold deposit and hence relies on a high throughput of ore to be profitable. To achieve the required high material throughput the dredge incorporates an overburden removal system which operates simultaneously with a conventional bucketline system.   The overburden system incorporates a cutter wheel and suction pump configuration which is dedicated to removing the low grade (5 mg gold/m3 gravel) overburden. The bucketline conveys the richer grade payzone gravels (up to 890 mg/m3 gravel) to the recovery plant mounted onboard the dredge. The horizon for the overburden system approximates 15 m and the payzone terminates at the interface of the old man rock and the alluvial gravels at a variable depth averaging 22 m.   From a mechanical engineering perspective the dredge is a machine comprised of two materials handling systems which are controlled by Operations Staff and electronic process control systems.   The availability of such a materials handling system is a function of four variables: 1. The environment that the machine operates in. 2. The ability of the people operating the machine. 3. The design of the mechanisms, the configuration that they are grouped in and the effectiveness of the process control systems which control the mechanisms. 4. The procedures utilised to predict the performance of the machines and the skill of staff to analyse that data and carry out effective maintenance.

Jan 1, 1989

Multiple regression analysis was used to predict elemental concentrations of copper and nickel in soils from consideration of the concentration of these elements in vegetation in an ultrabasic complex in New Zealand. Regression equations were computed from sixteen independent variables involving concentrations of ten elements in plant ash, and various physical factors such as slope and altitude of the site, and height of the tree. One elemental and one physical variable were significant for nickel at the 90 per cent level of probability and five elemental and two physical variables were significant for copper at the same level. Use of the regression equations explained 32·5 per cent and 26·5 per cent of the variance in the respective relative accumulations (amount in plant divided by amount in soil) of copper and nickel.Predicted concentrations of copper and nickel in soils agreed more closely with the observed values in the soils than did the levels of these elements in plant ash.Although the results may specifically apply only to the test area, the principles should have universal application.

Jan 1, 1972

Radioisotope x-ray methods for the on-stream determination of copper, lead, and zinc in mineral product slurries were developed, and were successfully tested at the plant of Cobar Mines Pty. Ltd.The tests were made in three stages. Measurements to determine the precision of analysis were made initially on briquettes of the mineral products. The effect of slurry solids content variations was then determined by measurements on the mineral products in a recirculating slurry loop. The radioisotope analyser was finally tested in a series of on-stream measurements in the plant.Copper, lead, and zinc in flotation feed and in copper concentrate were determined to a precision ranging between 1·4 and 15 per cent of the mean element concentration in the slurry solids. These precisions are within limits required for plant control purposes at Cobar.

Jan 1, 1971

Ledcap Pty Ltd has developed two software tools for assisting in the determination of life-of-mine (LOM) trucking requirements. The first tool generates haul paths and the second calculates truck travel time over these paths. The two step approach allows the paths to be viewed and if required edited, to better represent the actual site haul routes.The first tool automatically creates haul paths between the mine bench and the dump. To do this the user supplies a master haul route and a scheduled block model. The master haul path and the block model are interacted to create multiple haul routes, one for each pit/dump bench pair in each scheduling period. Each path carries with it a record of the scheduling period it represents and the dry tonnage hauled over the path in that period.The second tool calculates truck travel time over the path. Data from the manufacturer's rimpull and retarder curves are used to calculate accelerations and speed over each segment of the haul path. As the paths are derived from digitised representations of mine haul routes the path f les often have over a hundred segments. This detailed representation of the haul route allows the software to automatically adjust speed for different radius corners and accurately simulates the changing accelerations over the gradient changes that occur in real life mine ramps. Rolling resistance can be specified at a global level, at a segment level and at a period level. This allows rolling resistance to be changed seasonally as well as spatially.Life-of-mine trucking studies attempt to calculate an accurate answer from extremely variable inputs. This paper will detail the features of the two software tools and how the tools provided in the software can assist the mine planner to have greater confidence in their life-of-mine trucking requirements and the subsequent production capacity inputs to their scheduling calculations.

Dec 6, 2010

The mineralogy and textures of a portion oC ore from the 25 level northern orebody, North mine, Broken Hill are described. This ore, in places, contains up to 70 per cent cubanite (CuFe2S3 ) which has crystallized directly with other sulphides and associated gangue minerals.Several breakdown reactions involving the cubanite are also considered.

Jan 1, 1969

The commercial application of electrolysis to zinc sulphate solutions for the production of metallic zinc is a development ·of the past twenty years. Earlier attempts failed to give satisfactory results, chiefly because certain harmful elements were either not recognised as being present in the solution, or, if recognised, suitable methods of removal had not been developed. The electrodeposition of zinc from zinc sulphate solution is extremely sensitive to the influence of a great many factors, all of which appear to be closely inter-related.Some of these factors tend to minimise the necessity for a high degree of purity of the solution, while other factors aggravate the harmful nature of certain impurities.The relationship existing betweBn the various factors in zinc electrolysis makes a general discussion of the injurious effect of impurities very difficult since, under one set of conditions a given concentration of an impurity may be of minor: importance, where its under another set of conditions the same concentration of that impurity may prove dangerous to successful electrolysis.

Jan 1, 1934

By Penrose E. K

With the exception of occasional periods, when up to 80% of oxidized ore was treated, the G.M.K. plant treated all sulphide ore until October, 1939. The treatment was, briefly, as follows:The ore was ground to approximately 17% plus 200 mesh Tyler and agitated in cyanide solution, after straking. After agitation, the pulp passed through two stages of counter-current decantation washing in Dorr thickeners and was filtered once, to complete the precyanidation stage.The precyanide filter cake was repulped with flotation circuit solution and floated in a Denver Sub A flotation machine, consisting of twelve cells. The concentrates were roasted, cyanided and filtered four times before disposal to the' dam. The flotation tailings were thickened to conserve water and pumped away to a separate dam.The average results of flotation operations for the six months before October, 1939, are shown in Table 1.

Jan 1, 1942