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By Pate W. T

This paper describes the development of a dynamic flowsheet simulator for comminution operations. Object oriented software design allows the handling of multiple ore types, blended into multicomponent feed streams. Software objects have been c

Jan 1, 1998

By Bodnaras G. E, Sceresini P. A

The Filblast Cyanidation Process incorporates the advantages of intense high shear mixing, high dissolved oxygen concentration and high pressure to achieve extremely rapid gold dissolution rates. This is made possible by the unique design of the Filblast gas shear reactor. The reactor is a rugged and compact in-line device. The outer casing is protected by a polyurethane coating and the internal parts are of wear resistant polymer. The largest unit built to-date has overall dimensions of 1200 mm length by 300 mm diameter and has a capacity of 150 dry tonnes per hour at 40 - 45 per cent solids. Service life at this throughput is at least three months. The process may further be applied to high temperature leaching of refractory gold ores or other metals. Wear resistant metal or ceramic materials would be employed for this duty. Four mines are currently employing the Filblast Process for treating a variety of ore types ranging from highly reactive, almost impossible to treat, pyrrhotite/arsenopyrite to deeply weathered clay ore which forms a highly viscous pulp. The effect of shear thinning has resulted in improved adsorption kinetics resulting in higher carbon loading and reduced soluble gold loss. Total tonnage treated is approximately four million. Operating costs which include leasing and maintenance charges for the Filblast and pump power costs are about 16 cents per tonne. This is equivalent to about ten per cent of savings. Laboratory scale units having capacities up to 30 litres/min are available for test work but laboratory testing techniques so far developed do not accurately reflect the oxygen and cyanide savings which have been achieved in the plant.

Jan 1, 1994

By D Connelly

Quartz deposits are common in nature but the presence of quartz suitable for yielding high purity quartz is exceedingly rare. This paper describes a test work study on producing high purity quartz (HPQ) product to meet the tight product specifications of greater than 99.97per cent, including four and even five nines, for uses including, lighting and fibre optics and modern-day high efficiency solar panels. Due to demand in renewable energy applications the market for high purity silica solar panels known for their increasing efficiency and durability is rapidly growing. Demand continues to rise for the use of high purity quartz in semiconductors, electronics, imaging and sensor markets. Microelectronic components are created by chemically fabricating wafers of semiconductors such as silicon to obtain the desired transport of electrical charge and control of the current. The production of silicon metal from high purity quartz has been designated a Strategic Mineral by the European Commission and by the US Department of Justice due to the growing significance of this metal in various industries. The subsequent processing of quartz is the key step to adding value and aiding technological advances. Overall, the high purity quartz market is a highly secretive, specialised market with increasing opportunities for stakeholders. The attempt to produce HPQ in this work was carried out using an Australian quartz ore following a typical HPQ process flow sheet. The unit processes included primary crushing, scrubbing, magnetic separation, flotation, acid leaching followed by hot chlorination. The results indicate that grinding of quartz requires specialist equipment due to the hardness and extreme abrasiveness of the ore leading to additional iron contamination in the ground ore. The critical impurities were aluminium, iron, sodium, potassium, lithium, titanium, zircon, calcium and magnesium. The chemical refining was found effective. The hot chlorination process needed to be done at 1200°C in a chlorine – hydrogen chloride gas atmosphere. The risk of any gas being released during this stage is very serious and only specialist companies should and can carry out this step. More recent studies reported many new options that appear to facilitate the production of HPQ with the requisite purities more easily, but costly equipment along with highly trained operators are required and hence unlikely to become available in standard metallurgical laboratories any time soon.

Sep 1, 2024

By S Jeon, K Haga, A Shibayama, L Godirilwe, C B. Tabelin, I Park, A Buronov

Open pit/underground mining and mineral processing can generate large amounts of waste that contains sulfide-type minerals such as pyrite (FeS2), and it can produce acid mine drainage (AMD) when exposed to oxygen and water. This highly acidic wastewater contains heavy metals and this is one of the most serious environmental issues after mining operations taking several decades to completely remediate with high costs. For green mining, the present study focused on the development of a recovery technique for gold from an eco-friendly solvent, thiosulfate, by utilising mine wastes, tailings. First, gold recovery experiments in ammonium thiosulfate system were carried out using model samples representatively present in tailings (ie SiO2, Al2O3, FeS2, Fe2O3, and Fe3O4). The results showed that gold recoveries were negligible when using Al2O3, SiO2, Fe2O3, and Fe3O4 while pyrite shows a recovery efficiency three-fold as high as the maximum recovery efficiency when using others. Subsequently, the study also addressed the identification of the recovery mechanisms and post-recover process. The results indicate that tailings can be sufficiently utilised for gold recovery in the hydrometallurgy process and a further sustainable process can be established.

Sep 1, 2024

I have headed this paper with a question and for the impatient among you ûthe answer is no we have not run out of developments but, and it is a big æbutÆ, we need to be innovative and ahead of the game or ænoÆ will be æyesÆ before we know it.Why do I believe that our future lies in innovation? Thirty years ago, knowledge doubled every 14 years. It is now doubling every seven years. In 1965, Gordon Moore, one of the founders of the chip maker Intel, made an observation that growth in memory chip performance is doubled every 18 months which became known as MooreÆs Law. Now there is fibre law, where the transmission line capacity doubles every nine months and storage capacity, under disc law, doubles every 12 months. What does this mean? Well, firstly there is a massive rise in information flow and availability with no limits in growth for at least the next ten years. Secondly, unlike our grandfathers, we are most unlikely to be employed by the same firm for our working career - we may not even have the choice to stay with the same company. In a phenomenon Richard Foster and Sarah Kaplan (2001), borrowing from Schumpeter, termed æcreative destructionÆ, companies are unable to sustain market-beating levels of performance for more than ten to 15 years. In the 1920s the turnover rate of companies in the United States was 1.5 per cent, so a company could employ almost three generations from the one family. A company had a half life of 60 years. In other words, you could well be in the same working environment as your grandparents. Today the churn rate is estimated to be eight to ten per cent. A company has a half life of five to six years. So for large companies, as an employer or employee or as a contractor, your working environment has a 50 per cent chance of changing in five years. Innovation is the driver of this rapid rate of change. Innovation is not for the faint hearted (Cutler, 2001) but it is the core for success in the global economy. The rate of change in our world is not going to decrease. We must learn, not only to manage change, but to enjoy the process of changing û to ride the tsunami of the knowledge economy.

Jan 1, 2002

The Newmont Waihi Operations are centred on the Martha mine at Waihi, New Zealand. The mine has produced over 6.6 million ounces of gold from both openpit and underground sources since operations began in 1878. The current open pit operations commenced in 1988 and in the year to 30 June 2002 produced 129,790 ounces of gold at a cash cost of USD122 per ounce. This paper provides an overview of current operations and future directions.

Jan 1, 2002

By B Zhao

Gas and coal dust, as potential harmful elements (PHEs) produced during mining, are considered two serious threats to the safe mining and the health of miners because of its explosive and pathogenic properties. To solve this problem, compound reagents enhanced water spraying technology was used to control the gas and coal dust in excavation working face in this study, and spray testing platform and wind tunnel were used to investigated the suppression effect for gas and coal dust. In addition, sink test, and agglomeration experiments were also used to analyse its suppression mechanism. Testing results show that the dust reduction efficiencies of compound reagents enhanced water spraying technology for four different particle sizes were 80 per cent, 91.43 per cent, 94.74 per cent and 94.46 per cent, and improved by 14 per cent, 10.86 per cent, 8.42 per cent and 4.25 per cent compared to water spraying. Moreover, the gas suppression efficiency also can be increased more than 20 per cent. Sink test, and agglomeration experiments results show that compound reagent improves the spreading efficiency of the liquid on the surface of the coal by changing its wettability, and this process can not only slow down the desorption rate of gas by forming a water-sealing effect in the coal surface indicated, but also promote the agglomeration of fine-grained coal dust.

Oct 12, 2022

By I Jabouri

There are many physical factors that can affect the self-heating rate of coal. The presence of seam gas has often been referred to as inhibiting coal self-heating due to the limited access of oxidation sites created by the presence of the gas adsorbed on the coal pores. Similarly, the presence of bed moisture in the coal also acts as an inhibitor of oxidation by blocking access of air into the pores. Gas drainage of a coal seam prior to mining removes both gas and moisture from the seam. Bulk coal self-heating tests in a two-metre column on both gassy, as-mined and gas-drained, dried high volatile bituminous coal show that removal of gas and moisture from the coal accelerates the rate of self-heating to thermal runaway from 8.5 days to 4.25 days, from a start temperature of 30¦C, with an airflow of 0.25 L/min. The corresponding gas evolution pattern for each of these situations is different. Therefore, it is necessary to take this change in coal condition into consideration when developing a spontaneous combustion management plan.

Jan 1, 2005

By Short KC

The Hunter Region, with a major part of the coal resources of New South Wales and a long history of coal mining, has experienced a rapid expansion of coal resource development in recent years. While there are inevitable conflicts between mining, urban development and related infrastructure, and between mining and other resources, the application of sound planning practices, and improved co-operation and co-ordination among the various parties, helps to reduce such conflicts. The planning process involves consideration of factors such as transport- ation (including port facilities), mine subsidence, provision for surface facilities, a,iC the need for buffer 'ones. In addition, provision must be made for urban expansion, often co-existing or in close proximity to present or future coal mining development. Approval of coal mining developments takes place within the legislative framework of the Environmental Planning and Assessment Act, 1979 (EPA Act), the Coal Mining Act, 1973 (CM Act) and the Mining Act, 1973. Considerable effort has gone into stream- lining and co-ordinating the procedures under these Acts. The EPA Act provides for regional and local environmental plans, as well as a linked process of development control and environmental impact assessment. The CM Act provides for the grant of exploration and coal mining titles and mechanisms for the responsible management of Mining.

Jan 1, 1987

By Dolan P

Various operating practices have been developed over many years to ensure safe and efficient production from the 1100 orebody. Some of these practices are described.

Jan 1, 1982

By Y Peng, D Liu, S Vink, B Wang

There have been strong industrial observations that clay minerals have a deleterious effect on mineral flotation grade and recovery. However, rigorous explanation on the role of clay minerals in flotation and effective ways to reduce their negative effects are not available. In this study, the flotation behaviour of low quality and high quality coal samples were examined at the Xstrata Oaky Creek Coal plant, and laboratory in fresh and recycled water with high ionic strength. Anionic and non-ionic dispersants including lignosulfonates and triblock copolymers were also tested with an objective of improving coal flotation in recycled water. It was found that overly stable froth was produced in the flotation of both low quality and high quality coal samples in saline water. Speciation modelling indicated precipitation of hydrophilic components which may adversely affect the flotation. Despite the overly stable froth, saline water produced much higher combustible recovery than fresh water without significantly losing the product quality. Lignosulfonate dispersants displayed a potential to improve the flotation in fresh water, but not in saline water. Significant flotation improvement was achieved with the triblock copolymer examined in both fresh and saline water.CITATION:Liu, D, Wang, B, Peng, Y and Vink, S, 2012. Determining the effect of clay minerals on coal flotation using saline water, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 151-158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The New Broken Hill Consolidated Airshaft is the first major undertaking in the development of New Broken Hill Consolidated Ltd's. property, which adjoins that of The Zinc Corporation Ltd. on the latter's southern boundary.The Zinc Corporation ore-body has a southerly pitch. The Zinc Corporation's New Main Shaft is 1000 ft. north of the common boundary, and the general plan of development of the New Broken Hill Consolidated property is by driving south from this shaft on the lower levels. No downcast airway from the surface was available south of the Zinc Corporation's New Main Shaft; this shaft acts as the main downcast to the bottom of the Zinc Corporation mine, the general air flow then being northward and upward to the upcast shaft at the extreme north end of the Zinc Corporation property.Rock temperature is 920 F. at 2000 ft., increasing by 10 Fahr. each 72 ft., the rock temperature at 3000 ft. being estimated at 1060 Fahr. With the general air flow northward from the Zinc Corporation's New Main Shaft, adequate ventilation under these temperature conditions would not be practicable for any great distance south of this shaft without another main airway from the surface. Accordingly the New Broken Hill Consolidated Airshaft is being sunk at a point 1000 ft. south of the common boundary, i.e., 2000 ft. south of the Zinc Corporation's New Main Shaft, to ventilate future New Broken Hill Consolidated workings and that part of the Zinc Corporation mine between the boundary and the New Main Shaft.

Jan 1, 1940

By Jansen N

Production from the narrow, high grade silver-lead-zinc orebodies below 15 level commenced in mid 1985.Geological, mining research and recent mining experience determined that a mechanised drill, fire and muck cycle would be the most suitable method.Ground conditions are predicted to be worse than in other cut and fill (MICAF) areas at Isa Mine, owing to the increased depth, more variable dip of the orebodies and the increased effect of major geological structures.Mechanised ground support and tight filling techniques feature in controlling these expected adverse ground conditions.

Jan 1, 1985

By A Specht, A Müller, V Montenegro, S Winkler, E Klaffenbach, A Schmidt

In the process of primary copper smelting in flash smelting furnace (FSF), the ratio of iron to silica (Fe/SiO2 mass ratio) primarily determines the slag viscosity and magnetite formation. Viscous slag does not only cause difficulties in daily operation, such as in tapping, it also increases the copper losses to slag. Thus, keeping the Fe/SiO2 mass ratio at the desired level is an important aspect of FSF and slag cleaning furnace (SCF) operation. In this study, the improvement of the Fe/SiO2 mass ratio was conducted in two steps: First, the optimal Fe/SiO2 mass ratio was derived based on thermodynamic data. Based on this analysis, appropriate control limits were determined. Second, this range of favourable Fe/SiO2 mass ratios was implemented into operation by an advice-based control system, which suggests the addition of silica based on the analysis of SCF slag. As this approach was successful, the same advice-based control system principle was adapted for the coke addition to the SCF. After testing the new advice-based control for several months, the production data confirm the predictions by thermodynamics: since the prediction was implemented as an advisor, the copper and magnetite content in SCF slag is significantly reduced and viscous slag is reported less often by operations.

Aug 21, 2024

We are moving into an era where we experience the consequences of the skills crisis û namely many resource models have been generated by inexperienced people under pressure to deliver high quality resource estimates in unsupported environments, often without technical mentors. These resource models form the basis of our decision to pursue actual mining. This begs the question: how valid are the resource models that form the basis of our mining decisions? This paper presents various model validation tools such as comparison of input and output statistics, swath plots, sectional or bench comparisons between drill holes and models as well as a variety of other approaches. Each model validation tool currently used in industry is examined:how the tool generates results,what assumptions exist,what constitutes a pass/fail in the test, and what interpretations to consider when using the validation tool. Each validation toolÆs suitability and the inherent flaws in the underlying assumptions are also discussed. These are supported with examples of good versus bad validations. Our principles based reporting codes provide flexibility in how models are generated and what approaches and/or parameters are used to generate resource estimates. This flexibility works well when used by experienced practitioners. However, our reporting codes assume a level of experience not always available in the current skills crisis. This paper seeks to provide minimum model validation prerequisites for model acceptance and suitability, regardless of the resource analystÆs experience. As we move forward, our immediate challenge is to ensure our baseline resource models are material, transparent and competent.

Jan 1, 2009

By M S. Henderson, R D. Alorro, L G. Dyer

An alternative leaching system for rare earth element recovery from monazite is under development. The initial stage utilises oxalic acid to convert the rare earth phosphate into an oxalate salt through dissolution and reprecipitation and it is the efficiency of this stage that governs the overall recovery achieved. It has previously been proposed that lixiviant consumption is the primary limitation in this process. This work further investigates a range of conditions in an attempt to further elucidate the factors influencing the achievable conversion in this stage. It has been shown that the pH may be governed by multiple reactions both consuming and producing acid (thus the mild change over time). The importance of proper mixing and potential to operate at lower temperature with only moderate impact on kinetics has also been demonstrated. Staged/sequential leaching is more effective in fresh solution as opposed to restoring the lixiviant concentration with subsequent reagent addition, suggesting some impact of solution composition. However, contrary to previous findings, subjecting the leach residue to fresh solution resulted in significant decline in leach rate and overall dissolution. This may be because a greater proportion of conversion was achieved in stage 1 in this work than in previous investigation. This may indicate that eventual passivation or the presence of some more refractory REE minerals limits dissolution. Iron dissolution was relatively consistent upon exposure to fresh solution, displaying the ability of the solution to continue to leach the goethite component of the concentrate.

Aug 24, 2022

By V Sanmartfn, J Torracchi

The broad biodiversity of our country is manifested through several different biological forms. From the villages of Portovelo and San Gerardo in the southern part of Ecuador, some samples of water and rocks were taken in order to identify the native micro-organisms which take part in the natural processes of leaching of sulfurous minerals. The presence of Spp Thiobacillus ferrooxidans was determined together with a fungi sample which has not yet been characterised by the current workers. These have been isolated, grown, experimented and conserved in appropriate cryogenic environments. The present research intends to study the individual and group adaptation of the bacteria and the fungi upon suitable systems of agitation and ventilation, in combination with several different concentrations of refractory auriferous samples. These refractory samples were derived from old mine workings and the experiments were performed to test the effectiveness of the isolated species in bioleaching as pre-treatments upon the cyaniding processes. The capability of these bacteria to develop in environments with high concentrations of cyanide has also been studied, to investigate the possible use of bacteria in the biodegradation of cyanide. The presence of Thiobacillus ferrooxidans in acid conditions has already been tested in advance, however, the presence of fungi species in these conditions are studied to prove their efficiency as another alternative for the bioleaching of refractory auriferous minerals and Baptista, 1998).

Jan 1, 2004

By Hartley JS, Wills KJA

The Thalanga massive sulphide deposit is hosted by Upper Cambrian rhyolites and volcaniclastics of the Mt. Windsor Volcanics near their contact with overlying dacites, rhyolites and sediments of the Trooper Creek Formation. The ores and host rocks have been subjected to a single strong deformation and to lower to middle greenschist facies metamorphism. A main lens with surface gossan dimensions of 55U m x 6 m dips steeply, plunges shallowly to the west and is offset by a series of normal faults. It is flanked by smaller lenses to the east where the mineralized horizon is stopea out by granite. The area to the east and south of the gossan is masked by Tertiary cover. A complex exhalite package is represented by banded sphalerite-pyrite- galena-chalcopyrite, massive pyrite and chalcopyrite and assemblages dominated by dolomite, chlorite-actinolite, tremolite, talc, barite and rare gypsum. Accessory tetrahedrite, arsenopyrite, bismuthinite, magnetite and native gold are associated locally. Pods of quartz-magnetite formed distally. The ores are underlain by strongly to moderately pyrite-silica-sericite altered rhyolites with the strongest alteration closest to an interred synvolcanic fault. This alteration is characterised by an enrichment in MgO, Na2O, FeS2 and base metals with a depletion in CaO and Na2O. There is a general enrichment in Pb and Zn towards the hanging wall with some enrichment of Cu near the base of the main lens due to replacement by ore tiuias near vent discharge sites. Zonation of Cu to 2n-Pb in also evident over narrow intervals

Jan 1, 1987

By Bhaskara Sarma P V R

Solvent extraction of cobalt from an ammoniacal ammonium sulphate medium was carried out using Di(2-Ethyl Hexyl) phosphoric acid in kerosene as diluent. The effect of ammonium chloride and ammonium sulphate on the extraction efficiency was studied. The extracted species in the ammonium chloride and sulphate systems were CoAz2HA.NH4CI and CoA3.HA.2(NH4)2SO4, respectively. Ammonia scrubbing and cobalt stripping studies were carried out from loaded and ammonia free organic Respectively.

Jan 1, 1992

By J Leem, S Mehrishal, J Kim, A Fereshtenejad, J Song

Rock mass discontinuity mapping plays a crucial role in developing a reliable Discrete Fracture Network (DFN), providing insights into the distribution of geometrical and mechanical properties of discontinuities. This enables an accurate assessment of geotechnical infrastructure and mining excavations. Data obtained through conventional mapping approaches are substantially limited by factors such as accessibility and subjectivity. Moreover, these conventional methods may pose inherent risks due to manual techniques, exposing practitioners to potential dangers. Recent digital developments in remote surveying techniques offer opportunities for safer and more reliable rock mass discontinuity surveys. These technologies allow extensive three-dimensional surveying and the production of high-resolution 3D surface models, applicable at any time. This paper presents a workflow for digital discontinuity mapping employing drone technology and photogrammetry. Additionally, the capabilities and challenges of applying artificial intelligence (AI) algorithms in the rock mass discontinuity characterisation process are discussed.

Sep 1, 2024