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By G Bournival, Y Pan, S Ata

A custom-made set-up that measures bubble coalescence time and the thin film balance (TFB) technique were used to explore the role of residual xanthate (potassium amyl xanthate, PAX) and salt (NaCl) on the adsorption of two frothers (methyl isobutyl carbinol-MIBC, and di-propylene glycolDPG) at the air-water interface. This paper is primarily focused on the comparison of these two techniques in studying the interaction between the flotation reagents and salt emphasizing their capabilities and limits. The results from the coalescence rig showed that the presence of PAX improved the stability of bubbles in both frother solutions and led to a bubble coalescence inhibition at 50–500 ppm DPG. These measures were compared with the results from the TFB. Findings from the TFB were overall in good agreement with the bubble coalescence time, but a higher stability level was observed in thin films under the same condition. The effect of salt on the frother and PAX mixture was also explored, and the results showed an adverse impact of the salt on the interaction of frother and PAX with both techniques. However, variations were found between them in some cases. The TFB is much more sensitive to the presence of dissolved gas and oil droplets.

Aug 24, 2022

By K Tungpalan, E Wightman, M Edraki, E Manlapig, L Keeney

The depletion of easily mined high-grade ore bodies resulted in the industry having to exploit lower grade, complex resources (Albanese and McGagh, 2011; Darling, 2011; Randolph, 2011). The trend is now towards mining and processing of low-grade and complex ores (Darling, 2011; Yingling, 1990). Variable geological and mineralogical characteristics, and complex mineralogy and texture can result in large variations in metallurgical response and also cause challenges in processing. (Carson, 1995; Lorenzen and Barnard, 2011; Yingling, 1990). Variability and the complex nature of ores are fundamental sources of risk that often cause the greatest economic impact (Dusci et al., 2007; Williams and Richardson, 2004). Hence it is important to effectively characterise these types of ore bodies and assess their processing performance (ie recovery, grade). To enable this, there is a need for the following: (i) characterisation of geological, mineralogical and metallurgical variability in the ore body; (ii) effective selection of drill core with characteristics that represent the range of ores in the entire ore body. CITATION: Tungpalan, K, Manlapig, E, Keeney, L, Wightman, E and Edraki, M, 2018. A systematic approach of sample selection to predict processing performance of an ore body, in Proceedings Complex Orebodies Conference 2018, pp 67–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

The Lihir deposit in Papua New Guinea (PNG) contains an estimated mineable reserve of 454t (14.6M oz) of gold in refractory sulphide ore. The Lihir Joint Venture has submitted a proposal to the PNG Government to develop an open pit mine and to install a process plant and associated infrastructure facilities on Lihir Island. The proposed process plant will employ whole-ore pressure oxidation technology, has a design capacity of 2.825Mt/a of ore containing 7.20 sulphide sulphur, and is expected to average 19.3t/a (620,000 oz/a) in gold production during its first 12 years of operation.An extensive program of process development testwork and feasibility engineering was completed to establish the process plant design for the Lihir Project. Summary results of this test-work as well as key design criteria, the process flowsheet, and major equipment selected for the commercial plant are presented and discussed.

Jan 1, 1994

By A Tolley

Bauxite residue or ‘red mud’ is a by-product of the Bayer Process, the primary process of alumina refining. Due to its high alkalinity and variable composition, its storage and disposal poses high environmental risks to water sources, surrounding ecosystems and human health. The high alkalinity (pH 12–13) is a significant factor in its classification as hazardous waste; to mitigate this, Australian refineries have integrated neutralisation processes into bauxite refining. Both sea water and carbon dioxide neutralisation processes are applicable. Multiple studies have demonstrated pH reduction from 12–13 to 7–10, depending on the method. The key advantages of CO2 neutralisation are that it allows for carbon sequestration and is more effective when utilised as a pre-treatment for recovery of metals, while sea water neutralisation is more established and has been integrated into two Australian refineries. This paper proposes the application of the bacteria Exiguobacterium oxidotolerans for bioleaching of iron from hematite in bauxite residue. The genus Exiguobacterium is characterised by its high levels of adaptability, halotolerance and alkaliphilic nature. E. oxidotolerans is successful at eluting Fe2+ from hematite via reductive dissolution, which complexes with oxalic acid produced during metabolism. This aquatic bacterium presents a novel process pathway for iron elution due to direct interaction of E. oxidotolerans with hematite via the cell membrane and operates within the pH range of neutralised red mud. The proposed mechanism is extracellular electron transfer, a microbial metabolic process where electron transfer is facilitated between bacterial cells and extracellular material. Currently this is being investigated for promotion of seaweed growth in coastal environments as soluble iron aids and fortifies colonies. This has potential downstream applications for cleaner iron and steel production. While theoretical, this paper explores the neutralisation, bioleaching and application of the Fe(II)- and Fe(III)-oxalate complexes formed.

Sep 18, 2023

By J M. Galvin

The traditional engineering approach to assessing stability is based on comparing resisting force (capacity) to driving force (demand), or strength to working stress. In underground coal geomechanics, considerable effort has been expended on quantifying the strength of rock structures. However, this has not been matched by advances in determining the load acting on these structures, reflecting a reluctance by some to embrace numerical modelling to assess load magnitudes and distributions. Numerical modelling is a valuable aid as loading environments are a function of both the stiffness of the mine workings and the stiffness of the superincumbent strata and are statically indeterminate in most cases.This paper defines stiffness, which is often confused with elastic modulus. It shows that, effectively, stiffness encapsulates geology, depth of mining, panel width, pillar width and mining height. Therefore, these factors are variables that need to be taken into account when determining stress magnitudes and distributions about mine workings. A range of examples are presented that illustrate the significance of the stiffness of the superincumbent strata on surface subsidence; the magnitude and distribution of pillar and abutment load; and aspects of bord and pillar mining, pillar extraction and longwall mining. These examples provide bases for identifying the limitations of some empirical approaches to mine design, identifying how to compensate for some of these in design processes; and emphasising the need to make greater use of numerical modelling in understanding and quantifying loading environments in underground coal mining.CITATION:Galvin, J M, 2014. The significance of superincumbent strata stiffness and its impacts on coalmine design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 3–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By J J. L du Plessis

Escalating energy and electricity costs have become one of the biggest expenditure drivers in mining operations. During the last eight years, energy costs have trebled when expressed as a percentage of total running cost in South African mines. Power consumption on mines is controlled by three main strategies, namely load clipping where energy use is reduced for parts of the day, load shifting where energy use is shifted to other parts of the day, and energy efficiency where energy use is reduced permanently.To reduce the operating costs of ventilating and cooling underground mines continuously, system optimisation studies must be completed. A part of this paper describes methods that can be used to reduce energy usage by optimising cooling and ventilation systems during planning and in existing operations using network simulation models that accurately reflect the current and planned ventilation conditions. These models are used to examine various options for improving the overall ventilation and cooling efficiency. Furthermore, an overview of refrigeration and cooling practices, and ventilation strategies is presented.Ventilation-on-demand and cooling-on-demand strategies have the potential to reduce both the capital and operating costs associated with mine ventilation and cooling systems. In addition, it has been proven that modern strategies and energy-efficient tactics are technically feasible.It is also important that the correct equipment selection is made. This must be based on the best technology with the highest energy efficiency. Where equipment replacement is being considered, energy efficiency must be one of the key decision drivers.In this paper a number of studies were presented and from the experience and the data presented it is clear that a large financial benefit is possible through optimising ventilation and cooling during the planning of mines or within an existing operating mine.CITATION:du Plessis, J J L, 2015. Strategy and tactics implemented to achieve energy-efficient ventilation and cooling of mines, in Proceedings The Australian Mine Ventilation Conference, pp 9–18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By C Hoffmann

Given that each year, 30–40 per cent of mining industry deaths are attributable to failures of vehicle interaction controls (EMESRT, 2023), the mining industry is now armed with a growing body of knowledge from EMESRT (Earth Moving Equipment Safety Round Table) and ICMM (International Council on Mining and Metals) global vehicle interaction initiatives over the past years, that enables mining companies, OEM’s and technology providers to work together to develop and implement more effective controls and drive the adoption of capable solutions. Leveraging 20 years of experience as a global technology provider of Proximity Detection System (PDS) and Collision Avoidance System (CAS) solutions for surface mining operations, Wabtec Digital Mine Technology shares key insights for ensuring the effective selection, implementation and integration of these technologies into existing mine site controls and mining operations for effectively reducing vehicle interaction risk enabling mines to drive towards ‘zero-harm’ objectives. Topics covered include: alignment with industry best practice for controlling vehicle interaction risk by EMESRT and ICMM, importance of the maturity of EMESRT levels 1–7 vehicle interaction (VI) control framework, managing expectations that PDS/CAS is a ‘silver bullet’, alignment with industry functional – performance – technical requirements, proximity detection versus collision avoidance, sensor performance and fusion and limitations, rules engine intelligence critical to mitigating nuisance alarms during normal operations, system health monitoring and reporting, human factors engineering and operator acceptance, implementation strategy, installation standards and quality control, change management program, training programs, reporting and data analytics with actionable insights and maintenance strategies. Insights will also be provided on the challenges moving from EMESRT levels 7 (operator awareness) and 8 (advisory controls) to level 9 (intervention controls) as it’s a journey not an out-of-box solution, the growing demand for coexistence of CAS and Autonomous Haulage Solutions (AHS), functional safety approach, value added systems integration and the applicability of new emerging technologies.

Apr 16, 2024

By Nilmani M, Malone J, Taylor RN, Floyd JM, Gray NB, Fountain CR

CSIRO staff and University of Melbourne staff and students collaborated in an intense programme of investigation on the CSIRO 50 kg Sirosmelt pilot plant.In two days of operation copper matte converting and zinc slag fuming trials were performed, whilst investigation of the process dynamics and process chemistry was carried out. This exercise is an example of the techniques available for process evaluation, which can rapidly advance the understanding of pyrometallurgical operations by use of a team approach covering a wide range of experiments.

Jan 1, 1985

The Prominent Hill copper-gold deposit is located approximately 150 km north west of Olympic Dam, on the southern margin of the Mount Woods Inlier in South Australia. Its discovery in November 2001 resulted from the application of a geological model developed from geological, geophysical and petrophysical data pertaining to the Olympic Dam deposit. The discovery has dispelled the notion the Olympic Dam may be unique, and that another deposit like it is unlikely to be found. The Prominent Hill mineralisation is hosted by haematite-matrix hydrothermal breccias, which have suffered extensive iron-sericite-silica alteration and overprinting. Copper, gold, barium, fluorine, uranium, cerium and lanthanum are all intrinsically associated with the hydrothermal iron. Breccias intrude an east-west striking, fault-controlled sedimentary succession, which is flanked to both the south and north by volcanic complexes. Many similarities between Prominent Hill and Olympic Dam are documented including geological setting, mineralogy, breccia styles, and alteration. Differences relate largely to the nature of the immediate host rocks. The similarities and difference provide key data for improving exploration models for this style of iron oxide copper-gold deposit, both within the Gawler Craton as well as globally.

Jan 1, 2004

By S J Riley

The cover (cap) over the tailings pit at Nabarlek uranium mine must be structurally stable as it will act as a barrier to radon gas emission and have to contain other long-lived radionuclides. Structural stability is primarily an issue of erosional stability in the context of a design life of thousands of years. The primary agent of erosion is fluvial, dominated by rainwash, overland flow, filling and gullying in the local area. Other agents of erosion are of less concern although biogenic agents of erosion (eg termites and windthrow) may enhance fluvial activity. Several methods may be used to assess erosional stability. They fall into two main categories, namely erosion modelling and geomorphic modelling. The former is illustrated by the Universal Soil Loss Equation in which parameters describing aspects of the geotechnical and hydrological properties of the rehabilitated surface are used as input for the modelling of erosion rates. The latter is illustrated by estimates of gully and valley erosion using empirical models. Estimates of the erosion rates and stability of the Nabarlek cover are presented. The two main techniques are complementary and it is argued that rehabilitation design must make use of both approaches when estimating erosion and geomorphic stability. More recent developments in geomorphic modelling using numerical techniques incorporate both approaches.

Jan 1, 1994

Brand se Baai, on the North-Western Cape Coastline of Southern Africa, is the site of the Namakwa Sands Limited Heavy Mineral Sands Mining Operation. The mine is a 14 000 000 tonnes per annum open-cast strip-style mining operation using truck and excavators to mine the sand. The orebody consists of relatively unconsolidated sands reworked by fluvial, marine and aeolian mechanisms. The total orebody includes three primary ore types, namely the Red Aeolian Sands, the Dorbank (a hardcap layer) and the Orange Feldspathic Sands, which forms the bulk of the resource. Mine planning and scheduling is done using a 50 m + 50 m variable bench height system with three primary bench heights. The Aeolian and Dorbank each have a bench that varies with their thickness of up to a maximum eight metres and the Orange feldspathic sand, a standard bench height of eight metres. For a number of years Namakwa Sands used a complex 2D, Datamine Based, macro system to perform the resource evaluation and mine design. As the mining operations expanded it became clear that a complete system redesign was required to cope with the increasing operational pressures coming to bear on the old system. The biggest challenges facing any replacement system are the sheer scale of the mining operation (16 km long and 7 km wide resulting in a minimum of 30 000 individual 50 m + 50 m mining blocks), the size of the geological data files (up to one gigabyte) and representing the benching system accurately (as the benches follow the topography and are not horizontal). In addition to these large-scale issues, the ability to run multiple mine design scenarios was required, an aspect which the old system was unable to perform adequately. Based upon these primary difficulties, a new business process was developed which required a complete rethink of the mine design methodology as well as the creation of a new system to deplete the resource model, produce monthly reconciliation evaluations and create a ultimate pit limit based on the operations mining cost model. Using a system based on the Earthworks Mine2-4D Mine Design and Scheduling System (with its mine design and scheduling specific tools), as well as a small, customised program, massive time-savings have been made. It is now possible to run several life of mine scenarios in the same timeframe that a single life of mine run took under the old system. This paper will present the methodology and business decisions behind the new Namakwa Sands system, and detail the restructuring and development used to deal with the large data set sizes and long processing times inherent in the old system. Future enhancements to the system that will make it more generically applicable to open-cast mining scenarios will also be dealt with.

Jan 1, 2003

By Mez W

the German ruining industry uses different residues for hackfilling and stowing. A hydraulic pipe conveying technology for these materials has shown advantages for the transportation into the mine. Pipeline conveying systems are able to bridge long distances, they save room within the underground workings and they save staff and costs. Absolutely necessary for successful use of the hydraulic conveying technology is the knowledge about the unusual non-Newtonian flow properties of solid/liquid mixtures like pastes and slurries. The flow resistance of these materials cannot be described easily by one viscosity. Owing to a yield point and a pseudo-plastic behaviour the viscosity changes with the shear rate and with the streaming velocity inside the pipe. Also these flow behaviours depend very sensitively on the liquid/solid-ratio, often so dramatically that gravimetric or volumetric dosing equipment is not in a position to control the production of backfill pastes. Quality changes of the solid raw materials (particle size distribution, density, mineralogical composition) lead to additional difficulties. The first experiences with hydraulic backfilling plants were troubled by plugged pipes. a bad backfill quality caused by unnecessarily high water content and high costs for chemical binders to solidify the backfill. The installation of viscosity controlled paste production leads to success with the hydraulic backfill technology. A development of the l)MT, a bypass pipe-viscometer, has been the key technology. The system is able to analyse on-line, difficult, sticky and abrasive substances and determine their non-Newtonian flow properties. Because the system measures real physical values it is in a position to pre-calculate process relevant parameters like the pressure drop of the backfilling paste in the conveying pipeline. Newer types of the viscometer system also measure the slurry density and calculate its composition. These systems have proven a success controlling backfill paste production plants. They offer it secure prevention of pipeline plugging and a production of high quality backfill pastes with a water content as low as possible.

Jan 1, 1998

Many types of micro-organisms inhabit iron ore deposits contributing to biogenic formation and conversion of iron oxides and associated minerals. Bacteria such as Paenibacillus polymyxa are capable of significantly altering the surface chemical behaviour of iron ore minerals such as haematite, alumina, calcite and silica. Differing mineral surface affinities of bacterial cells and metabolic products such as proteins and polysaccharides can be utilised to induce their flotation or flocculation. Mineral-specific bioreagents such as proteins are generated when bacteria are grown in the presence of haematite, alumina, calcite and silica. Alumina-grown bacterial cells and proteins separated from such cells were found to be capable of separating alumina from haematite. Biodegradation of iron ore flotation collectors such as amines and oleates can be effectively utilised to achieve environmental control in iron ore processing mills.

Jan 1, 2009

By R G. Reddy

The complexity in treating environmentally harmful impurities such as As, Sb, Bi from the base metal matte or metal in the smelting stage are responsible for the high cost of the refining process. The impurity capacities (such as arsenic, antimony and bismuth) of slags were calculated a priori using Reddy-Blander (RB) model. The capacity predictions were for a wide range of matte and slag compositions in copper smelting conditions. The calculated impurities capacities and impurity distribution ratios results are in good agreement with the available experimental and industrial slags data. The a priori knowledge of impurities is useful for reduction of energy consumption and enhanced environmental control in the current and future non-ferrous metal processes.

Aug 21, 2024

Early in 1950 a new laboratory was set up to deal with problems in mineragraphy, petrology and metallography. This paper describes the equipment, the organisation and association of the laboratory with the various departments of the company, the work that has been done and future plans.At Mount Isa it was soon realised that the microscope would play a most important role in mineral dressing problems and aiding geological research.As early as 1928, R. J. Colony submitted a petrographic report on Black Star ore for Consolidated Limited; much later, in 1934-5 Dr. Grondijs published for Mount Isa Mines Limited a preliminary study of the Mount Isa orebody, followed by a mineragraphicinvestigation of mill products, and in 1937 a Study of Mount Isa Ores by H. GrondIjs and C. Schouten appeared in Economic Geology, for June-July. Other papers dealing with the petrology and mineragraphy of Mount Isa ores are appended at the end of the paper.The mill research metallurgical staff has endeavoured to incorporate mineragraphy in solving milling problems and determining the effectiveness of laboratory as well as examining minerals sent in by the geological department.For many years the amount of equipment available was limited and much of it was locally made or improvised. An improvised briquetting machine, and grinding and polishing lap gave moderate results in conjunction with an old, but serviceable, Leitz microscope. However, for more detailed and accurate work not possible with improvised equipment, many mineragraphic problems were sent to specialist in.

Jan 1, 1953

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 mm depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37o (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998

The Favona Underground Project is located approximately two kilometres east of Martha Mine Open Pit in Waihi, 150 km south east of Auckland, New Zealand.   The underground reserve of 354 koz Au contained in resources of almost 600 koz lies within 600 m of the existing process plant presenting an attractive development target in a challenging environment.   The Martha Mine Open Pit is surrounded by urban housing on the north western edge of Waihi township and the Favona Underground abuts residences on the eastern edge of town. Environmental, community and social licence aspects influence project strategies as the new underground mine extends mining in a town that is planning for closure of current open pit operations in late 2006.   The Favona Underground Project has successfully passed through a detailed feasibility study, the third stage of the five stage Newmont project appraisal system. Methodologies used in the feasibility study and parallel permitting draw on a high level of stakeholder involvement to streamline the development and permitting phases.   This paper discusses the project appraisal process and design innovation required for developing an underground mine adjacent to town.

Jan 1, 2004

By Abdulhadi H. M, Soliman S. A

The Western Desert of Egypt is a part of the arid Great Sahara of Africa which extends from the Nile Valley in the east to the Atlantic Ocean in the west. It is covered by a sedimentary sequence of Mezozoic and Teriary rocks. Recently this part of the country (about 65% of its surface area) has attracted an increasing attention in the plan of finding new agricultural and industrial communities outside the crowded Nile Valley. The plan aims to reduce the high population density in the narrow Nile Valley and to cover a considerable part of the increasing food demands in the country of Egypt. Accordingly, the groundwater exploration work in the Western Desert has been remarkably increased in the last decade, however it is still limited compared with the vast area of the Desert. The present work is a part of the groundwater exploration in the 6th October City, a new community located at 40kms west of Cairo. The rock exposures belong to a sedimentary stratigraphic section starting from the Cretaceous in the east to the Pliocene in the west. The Cretaceous outcrops due east are attributed to an almost N-S uplift and forms a thick massive limestone plateau which separates the present area from the Nile Valley. The Teriary section in the west have alternations of different porous formations such as the sands and sandstones which may acquire a good potentiality of groundwater resources. The previous groundwater exploration work included combined geological and geophysical investigations followed by exploration drilling. Although the area lies directly to the west of the Nile Valley, the discovered groundwater is saline and located at deeper reserviores compared with the groundwater in the Nile Valley. This groundwater was described as marine fossile water by the oil companies working in the Western Desert. From the geological point of view, it is believed that the Cretacious massive limestone plateau, in the east, roots to a depth which far exceeds the groundwater levels in the Nile Valley and acts as an impervious barrier between the aquifers in the Nile Valley and the area under investigations.

Jan 1, 1988

By B J. Wilde

Evaluating the resources and reserves in a mineral deposit requires many interdependent subjective decisions. The decision of stationarity is arguably the most important. This decision includes: the choice of domains that subset the entire deposit, modelling the boundaries of each domain, and understanding and considering the nature of the contacts between domains. Reasonable choices are made in consideration of the geological context, the available data, the goals of the study and the available resources for the study. This paper reviews aspects of the decision of stationarity in modern resource assessment with a focus on quantifying uncertainty and using numerical/statistical tools to help the geomodeller. The use of volume/distance functions to quantify uncertainty in domain limits is particularly important and is presented in detail. The use of contact plots provides help with the continuity of grades across domain boundaries. Realisations are not assembled as a branching combinatorial of all possibilities, but as a set of realisations that provide a measure of uncertainty. This paper amounts to a definition of stationarity for modern resource assessment.

Sep 26, 2011

Expert systems are a product of Artificial Intelligence (AI), a field of long standing, dedicated to the study of problem solving using heuristics, construction of symbolic representations of knowledge about the world, communications proce

Jan 1, 1998