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Australia has been an important producer of zinc minerals and metal for many years.Late in the last century Edgar A. Ashcroft, a versatile and enterprising electrical engineer proposed the treatment of zinc rich ores by roasting, followed by leaching to extract zinc, purification of the solution and electrolysis of the purified solution to produce zinc. Residues from the leaching operation were to be smelted in a lead blast furnace to recover lead, silver and gold.Ashcroft (1897-98) and (1898) has.given us a most interesting record of the attempts made at the Sulphide Corporation's plant at Cockle Creek near Newcastle, NSW, to put his ideas into practice. In spite of the best efforts of all concerned, including the use of electrolysis of aqueous chlorides and sulphates, zinc could not be deposited consistently and the project failed although lead smelting continued until 1922 (Woodward, 1965, p. 158). Based on later experience with Broken Hill materials the presence of undetected cobalt in the solutions was the likely cause of the inability to deposit zinc (Kirk and Othmer, 1956).

Jan 1, 1985

Since the discovery of coal of the Southern coalfield (Illawarra 1797, Burragorang 1806) coal mining has grown progressively to the thriving industry of today. Early shallow escarpment mining required no serious access development, but with extension of mining to further and deeper areas, sinking became necess- ary. Now, with 17 major shafts and 7 decline drifts in current use, new mining activities involve several current sinking and drifting projects, with more in prospect. Conventional sinking and drifting, using blasting and mucking techniques proven in recent years are normally in use, with attempts, recent and current to accelerate advances by boring techniques. With export and to less extent local market unpredictability, it is vital to produce mine establishment times to allow advantage to be taken of market upswings and there is great need for research and improvement of mine access construction as the major aspect of establish- ment.

Jan 1, 1976

By S Tyrrell, B Jackson, K Matson

Northern Star Resources Limited Jundee Gold Mine in Western Australia operates a comminution circuit that consists of a primary crusher, 3.85 MW semi-autogenous grinding (SAG) mill, 1.8 MW ball mill and pebble recycle crusher. In 2017, a secondary crushing circuit was installed to remove the SAG mill throughput bottleneck and increase production of highly competent underground ore from 1.35 to a minimum of 1.7 Mt/a.This paper discusses the findings from the trial phase, the circuit design, project delivery, site optimisation, and the plant performance.CITATION:Matson, K, Tyrrell, S and Jackson, B, 2018. The application of secondary crushing at the Jundee gold mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 485–496 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Mizuta T, Sakurai M

The Pine Creek Inlier produced 12 440 kg of gold in the period from the first gold discovery in the 1860s to the early-1900s. During the 1930s renewed large-scale prospecting took place and gave a foothold for today's gold mining operations. The rise of the gold price and improved mining methods in the 1970s and 1980s made possible low cost, bulk low grade mining operations. Various gold deposits including vein, network and stratiform types occur in the Pine Creek Inlier (Nicholson and Eupene, 1990). The Tom's Gully deposit is located 100 km south-east of Darwin in the Northern Territory. It is hosted in the early Proterozoic Wildman Siltstone and lies north-east of 1800 my old Mt Bundey Pluton (Figure 1). Around the Mt Bundey Pluton, there are several prospective base and precious metal deposits such as Quest 29. The Tom's Gully gold deposit was discovered in 1986 and yielded a total of 3070 kg of gold from ore averaging 9.35 g/t gold between 1987 and 1990 when the mining operation was terminated.

Jan 1, 1994

By Falbo A, Quarestima S, Cozza C, Barbaro M

A new synthetic reagent of the mercaptobenzoxazole class, 5- methyl-2-mercaptobenzoxazole, has been studied. This reagent exhibits powerful selective collecting action towards copper sulphides present in several complex ores, as demonstrated both by laboratory and pilot plant tests. Industrial production is expected to start in the near future. The way this reagent reacts with pure chalcocite has been studied utilising in situ FTIR techniques, adsorption tests, electrokinetic potential measurements and Hallimond cell flotation tests. The FTIR studies have indicated the nature of the surface phase. Adsorption isotherms obtained by the rest method have revealed the quantitative evolution of surface products, permitting the determination of surface coverage at various reagent concentrations. The electrokinetic potential has been utilised to verify the stability of individual species in diverse concentration ranges. Correlation of the results obtained has provided indications on the chemical interaction of this reagent with the surface and on the surface Arrangement.

Jan 1, 1993

By J-P Franzidis, E V. Manlap

Froth transportation characteristics have a significant impact on the flotation recovery especially in large flotation cells. The probability of an attached particle being recovered into the concentrate depends strongly on the location where it enters the froth phase. A mathematical model for froth transportation in industrial flotation cells was proposed (Zheng et al, 2004). The model has been tested on the experimental data obtained from testwork conducted at the Western Metals Hellyer lead/zinc concentrator. The results show that the model fits the experimental data well, especially when the froth is well developed (ie for a deep froth). The model fitting can be significantly improved by incorporating an air dispersion factor. However, the models encounter some limitation, ie inconsistent prediction at different froth heights, due to change in froth viscosity which cannot be modelled at the present time.

Jan 1, 2005

By B Vietnieks, N Widmer, L White, E Tata, J Natukunda, D C. Ilouga, J P. Tyler

The Republic of Uganda aims to exploit its’ significant, un-developed iron ore resources to supply the required raw material for developing its’ iron and steel industry across all the stages of the supply chain. Large prospects of iron ore exists in Uganda in the eastern (Tororo) regions and southwestern (Kisoro-Kabale) regions of the country. The Kisoro-Kabale iron ore projects covers mineralisation in hematitic banded iron formation (itabirite) in the north-eastern Congo-Tanzania Craton; covering ten Iron ore prospects. The prospects include Kamena, Karukara, Nyamiringa, Kyanyamuzinda, Rugando, Katagata, Rwengongo, Kijuguta, Kihumuro and Katuna. High-grade hematite ore prospects in south-western Uganda have known grades ranging from 55 per cent to 68 per cent iron ore content with an exploration target estimated at over 500 million tonne (Mt). Small scale production of iron ore from the south-western regions provide raw material to existing steelmaking and direct reduction iron ore plants located in the Jinja and Iganga districts of eastern Uganda. Large quantities of iron ore and other steelmaking raw material, however, are required to be imported into Uganda due to the limited exploration and development of their own iron ore mining operations. A joint collaboration between the European Union (EU), the Department of the Geological Survey and Mines (DGSM), Ugandan Ministry of Mines in partnership with Australian drilling and mining consultancies, ADT Africa and Kalem Group as a EU funded project was undertaken during November 2022 and September 2023. Exploration and evaluation of the ten iron ore prospects in south-western Uganda was undertaken through geological mapping, drilling, assaying, and technical studies with the view to attract investment for the development of Uganda iron ore mining and steelmaking industry. The collaboration developed mineral exploration policy, guidelines and standards, an iron ore exploration manual, a geological data management policy, and to support the sustainable development of iron ore mining in Uganda through building the capacity of local Ugandan geology and mining personnel through the transfer of knowledge and expertise from experienced iron ore experts. The quantification of these resources is an important first step in assessing their economic potential and attracting mining investors. This paper presents an overview of the investigation program and the preliminary results as an important first step in attracting mining investors to this exciting new iron ore province.

Sep 18, 2023

By L Basnayaka, N Subasinghe, B Albijanic

"It has been recognised that the presence of clay minerals in ores adversely affect flotation performance. In this study, changes in rheological properties of the flotation pulps under normal operating conditions were studied with additions of bentonite and kaolinite clays at various concentrations. Zeta potential measurements were also carried out to determine the changes in surface charge due to adsorption of clay particles. The results showed that bentonite clay adversely affects floatability of pyrite while kaolinite clay had a lesser influence on flotation of pyrite. The addition of Ca2+ ions to the pulp containing bentonite modified the rheological characteristics and in turn improved the pyrite flotation. It was also observed Ca2+ ions suppressed the swelling properties of bentonite and altered surface charge properties of bentonite clay particles. It has been shown that the flow index affected the ultimate recovery and it may provide a means to monitor flotation performance in routine plant operations.Citation:Basnayaka, L, Subasinghe, N and Albijanic, B, 2016. Effect of Clay Rheology on Flotation of a Refractory Gold Ore, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 77–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By M Recabarren, A Echeverria, J Ronda, J I. Guzman, R Dodds, G Juarez, E Vila-Echague

A strategic mine plan is a fundamental part of any mining operation. It must provide a realistic and operative extraction and processing schedule, and yield the highest value for the business. For open pit mines, the problem can be modelled as a set of blocks representing the deposit, for each of which we need to decide if it is going to be mined, if so, when and where it will be sent (process, stock or dump).This problem can be proven to be of NP-Hard complexity. The traditional approach used by mining engineers to tackle this complexity is to separate the problem into more tractable components, solving each separately. The first step is to use the Lerchs-Grossman (LG) algorithm to obtain the final pit limit, as well as a set of optimised pit shells (nested pits), using different input prices. Then, using this input, operational phases are designed. Third, the set of phases can be used as an input for a phase-bench style optimisation, usually using a mathematical programming-based algorithm.There are, however, several problems with this approach. First, dividing the problem into simpler parts has the consequence that any compromises made at early stages limit the potential value left for the following steps. Second, LG is a static algorithm, with no concept of the time-value of money, capacity limits, opportunity costs, etc. Phase design is essentially a manual step, for which nested pits provide insufficient information in practice, and therefore the quality of the result in terms of potential net present value (NPV) depends strongly on the experience and expertise of the designer. This means that key input data such as commodity prices, different processes capacities and mine movement limits, are considered only at scheduling, when there is little room for optimisation. This sequential approach limits the potential value in each step, where a simplified problem is addressed, instead of addressing the real, and more complex problem, which is dynamic and should be solved as a whole.We present in this paper an algorithm, and its commercial software implementation, that addresses the dynamic problem as a whole, simultaneously and automatically creating a high-value strategic mine plan that adheres to basic operational constraints, determining dynamic cut-off grades and delivering a set of phases which can serve as a much stronger guide than nested pits for the final design. We discuss some of the key elements of the algorithm and propose a new methodology for strategic mine planning, where phase design dynamically responds to mining strategy definition. Results using different mining and operational parameters on a fictitious copper deposit are used as a demonstrative example.CITATION:Juarez, G, Dodds, R, Echeverria, A, Guzman, J I, Recabarren, M, Ronda, J and Vila-Echague, E, 2014. Open pit strategic mine planning with automatic phase generation, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 147–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By G Richmond, J R. Glen

Western Metals Mt Gordon Operation is a copper mine and processing plant situated 120 kilometres north of Mt Isa. The unique Mt Gordon copper process utilises a whole of ore acid/ferric pressure leach to produce copper cathode from the Esperanza massive sulfide copper orebody. Esperanza ore contains chalcocite, covellite and minor chalcopyrite hosted in a massive pyrite matrix. These ore stocks will be depleted in late 2003. Recently the process circuit has been upgraded to allow the treatment of lower grade Mammoth ores. These include the installation of a ball mill to complement the existing SAG mill, a single stage rougher flotation circuit and a tailings thickener. The leach bleed neutralisation plant was also upgraded at this time. Commissioning of these new circuits occurred in March 2003 and involved all the challenges of ensuring current production levels were successfully maintained while new process steps were incorporated into the whole circuit. This paper explains the background flow sheet of the patented Mt Gordon process and the reasoning behind the enhancements required for an already successful copper leaching circuit. Included are discussion of the influences of the new ores on individual process components such as comminution, leach chemistry and solid/liquid separation. Longer term ore processing options are also discussed.

Jan 1, 2003

By Chappell B

Backfill in the form of mine waste tailings has inherent problems associated with attaining adequate strengths upon placement. Fines are usually removed to ensure adequate drainage, which lowers the cohesive strength of the fill, leaving the fines to he placed in a tailings darn. Electro-drainage and electro-chemical grouting is examined to investigate its effects on densification and shear strength within a silty clay tailing having low permeability and shear strength. Two separate grouting mechanisms are observed for the iron and silica grouts used. Electro- osmosis is associated with iron grout that deposits within the tailing matrix under a converging pH gradient, and increases the permeability of the tailing. This process initiates cation exchange and causes cementing of the granular contact points between the clays. Electro-phoresis causes sodium silicate solution to deposit silica grout in the voids of the tailings. The resultant effect of these mechanisms results in an increase in cohesion, leaving the void ratio of the iron grouted tailings as it was but significantly reducing the void ratio of the silica grouted tailings.

Jan 1, 1998

By Takiuchi T, Kurita M, Owada S

This paper describes the possibility of the application of flotation to the separation of monazite from xenotime and of columbite from ferberite, which have been said to be difficult with generally used physical beneficiation methods. For Malaysian monazite and xenotime samples, a great difference is observed between the flotation recoveries at pH 7.5 using 1.0 x 10-4mol/1 dodecylammonium chloride (DAC). The grade and recovery of columbite in the binary flotation with both minerals result in 85 per cent and 67 per cent in the cleaning froth and 91 per cent and 51 per cent in the re-cleaning froth, without adding any scavenging stages. For monazite samples from various localities, the flotability is dominated by the electrostatic interaction between mineral surface and collector ion using DAC as collector, but the singular decrease of flotation is observed in the sample of which the crystallinity is low and the surface structure is rugged and complex. Otherwise, ferric ion in the flotation system probably dissolved from mineral is found to activate the flotation using sodium dodecylsulfate as collector. For columbite and ferberite, the separation is judged possible at pH 3.0 using 1.0 x 10'3mo1/l sodium oleate (NaOl) from the single flotation results of each mineral. In the binary flotation, however, columbite recovery in the froth is greatly diminished below that expected. This would be because NaOl is prevented from adsorbing on the columbite surface of which the charge is transformed more negative side by the specific adsorption of the tungstate ion dissolved from ferberite.

Jan 1, 1993

By J C. de Vries

When times are tough in the mineral industry û as they have been for some time û typical responses by mining companies are to cut costs and/ or increase production. The latter is seen to spread fixed costs, thereby also reducing unit costs per tonne mined. However, most mineral deposits respond to increased production rates by lowering ore grades, so the reduction in cost per tonne of ore does not necessarily result in a reduced cost per unit of metal produced. The authorsÆ experience is that this process often leads to a mine plan that is a long way from optimal. Producing to the point where marginal cost equals marginal revenue may work well in a manufacturing operation, but it is not necessarily the best strategy for a mining company with a depleting resource. Variations in tonnage and grade with depth, ore reserve optimism and a variety of other factors conspire to produce variations in production rates and grade that often result in suboptimal outcomes and potential mine failure. Added to this is the focus of industry analysts and senior corporate management on such measures as unit costs and ounces in reserves. This is perceived to have the perverse effect of driving the share price down when strategies are adopted that actually improve the value of the mining operation, and vice versa! Many mine failures can be prevented by a close examination of the tonnage grade curve and an understanding of how margins, net cash flows and resulting business risk change with cut-off grades and rates of production. A few relatively simple analyses early in the evaluation of a project can demonstrate the tradeoffs between the main decision parameters, leading to right-sizing of the operation. Once major commitments to major capital items have been made, and reserves have been publicly reported, optimisation of the operation becomes much more difficult than if it had been done earlier. Such investigations can also identify the upside potential and downside risks associated with factors outside the companyÆs control. Many strategies that may enhance value in the good times significantly increase the downside risk in the bad times. What is often called risk analysis typically looks at superficial issues, and does not evaluate the major factors leading to the potential for financial disaster. This paper illustrates some of these major risks, and demonstrates how they may be fully evaluated so that corporate decision makers can make fully informed decisions that take account of the real risks.

Jan 1, 2003

By J Ortiz

In almost all copper mining companies, mine planning is done considering different time frames, leading to long-term (life-of-mine) (LOM), medium-term (first three years) and short-term (first year, monthly, weekly, and up to daily plans). Shorter term plans are usually associated with more abundant information, hence models with lower uncertainty. However, they capture more of the variability found on the geological attributes. In long-term models, usually estimation methods tend to hide this variability, providing smoothed interpretations.Medium and long-term plans consider average values for the parameters and optimisation techniques are applied aimed at maximising the economic profit. Short-term plans, on the other hand, are made to comply with the medium-term promises, maximising the use of the available resources (equipment and processing capacities) and dealing with the variability not characterised in the previous planning stages. This generates an important gap between the short-term and the medium and long-term plans. A case study was made using an important oxide copper mine, where the variability found in the short-term plan has a large impact in the productive process, thus reducing the daily ore grade variability is an important goal. In this paper, this planning issue is addressed by creating medium-term mine plans using mixed integer programming which are compared using the output of a simulation of the daily extraction that is aimed at satisfying the daily constraints of the processing plant, the availability of mining equipment and the variability of ore grade. The result shows the expected gap between these mine planning processes, which suggests correcting some of the parameters used in future medium and long-term plans.

Sep 26, 2011

By Dobos SK

The Black Ridge Gold Deposit is located in the northern part of the Clermont Goldfield, which is situated at the boundary of the Bowen Basin and Anakie Inlier, Queensland. The goldfield comprises a series of NNW-trending semi-isolated basins, which are tectonically aligned with the Denison Trough, the west-most division of the Bowen Basin (Fig. 1-1).The main stratigraphic units in the deposits in younging sequence are the Anakie Metamorphics, the early Permian Blair Athol Coal Measures, the late Permian(?) White Section, and the Tertiary basalts which are regionally widespread, and intruded by abundant mafic and felsic plugs.

Jan 1, 1990

This study examines the application of Landsat TM data to the identification of hydro- thermal alteration in the arid terrain of the El Salvador region of north Chile. Numerical reflectance values were extracted from the digital Landsat TM data for a variety of rock surfaces, including four parts of the El Salvador gossan, for each of six spectral bands. These reflectance values were analysed statistically in order to select the three spectral bands, combined as a colour composite image, that are most efficient in discriminating different varieties of alteration and for general geolog- ical interpretation. The most cost effective com- posite image for this area is a combination of bands 1,4 and 7 as the blue, green and red components respectively, with simple contrast enhancement. This image is superior to some much more expensive enhancement techniques and allows unambiguous identification of areas of hydrothermal alteration larger than about 50m. The display includes a practical guide to the use of Landsat TM imagery for volcanic gold Exploration.

Jan 1, 1987

By Grieveson P, Terry B. S

Carbothermic reduction of sulphide minerals for achieving a selective separation of metallic species from complex minerals has been discussed by considering the prevailing oxygen potential during the course of reaction. Construction of univariant plots for the reduction of sulphides with carbon monoxide gas or carbon and in the presence of either lime or anhydrous calcium sulphate is the key feature of this work. The theoretical calculations for univariants in the Cu-Fe-S-O system indicated a preferential separation of metallic copper and iron by imposing a chemical potential. This is evident from a logarithmic plot of sulphur dioxide partial pressure against reciprocal temperature. The results are compared with empirical data for the reduction equilibrium. The reduction behaviour of the constituent sulphides are also discussed together with the experimental results and theoretically predicted phase stability diagrams.

Jan 1, 1992

By Saghafi A, Kelly M, Williams R. J

A two year program of research into the feasibility of long-hole drilling for improved gas emission control has been undertaken at Appin Colliery. State of the art equipment was employed involving cableless electronic surveying and down-hole motor drilling. The project involved the drilling of 1000 m long, in-seam boreholes in the Bulli seam and boreholes of similar length drilled cross measure and then in-seam along the underlying Balgownie seam. A new concept for gas drainage was defined, employing long-holes for both predrainage and post drainage.

Jan 1, 1988

By S Munn

Today, it can be said that the majority of mines utilise communications equipment in one form or another. Either for communications between staff making their day-to-day operations more efficient, or for emergency communications, as well as linking computer based mine management systems, and providing remote control over complex mobile and fixed machinery. With the advances in technology now available, we are moving into the next generation of mine communications equipment, using digital communications in the underground mine environment. It is a proven fact that an efficient underground mine communications system can help maximise production, by providing major gains in areas such as equipment and manpower utilisation, staff and vehicle tracking, reaction times to break downs and emergencies. In this paper we will describe some of the facilities that are currently available, as well as what will soon be available to mining and tunnelling companies around the world.

Jan 1, 1999