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By S Tierney, D Cumming-Potvin, I Thin, Y Potvin, D Grant

The preliminary modifying factors for future stope design in the Southern Mine Area of Olympic Dam consisted of only a single, arbitrary value of Equivalent Linear Overbreak/Sloughing (ELOS). In order to improve this, a study was conducted which developed a more comprehensive methodology for assigning ELOS, Equivalent Linear Lost Ore (ELLO) and Equivalent Linear Fill Overbreak (ELFO) to individual stope faces based on geotechnical and mining parameters. The approach used was to look at the simple cases, which were classed as vertical stope walls in good ground (RQD 80-100%), divided into wall orientations (North, South, East, West). The stope walls were also split based on the blasting practice used (toeing, parallel or a combination of the two). The expected ELOS and ELLO from these ‘base cases’ are then modified by parameters which have historically been found to affect stope performance (Hydraulic Radius and Q’). The size of the effect found in the historical data determines the ELOS / ELLO applied. The methodology was summarised in an easy to use flow chart and was applied to all of the proposed stope shapes for the Southern Mine Area and summarised per mining block. This allowed each iteration of the mine plan to be assessed in terms of overbreak (both rock and vertical fill exposures) and underbreak.

Mar 15, 2021

The authors have succeeded in providing additional rigour and clarity to the formulation and execution of the dynamic programming algorithm for optimum open pit limit determination. The inclusion of the blocks on the J + 1 column in the search for Pmax, and constraining this search with blocks assigned a value of negative infinity, ensures an optimal solution within the defmed blocks. The effect of the negative infmity blocks is to preclude mining along the diagonal blocks from the first row that they occur in. Figure 1 graphically illustrates the effects of this on the calculation of P. A practical application for constraining mining with negative infmity blocks is the case where the pit outline is defined by lease boundaries and not by the value of blocks to be removed. Any legal, social or physical constraint could be accounted for in the same way.The danger in applying this technique is that the negative infinity blocks will override any other more profitable solutions that may exist. This is in fact what has happened in the example that the authors use. If a further column is added to the left hand side (column -1) and the calculation is carried out again, a more optimal x-section can be found. (If the negative infinity values are removed the same result is obtained.) This gives a pit value of 112 as against the 108 of the authors' optimal pit. This calculation is shown in Figure 2. Lerchs-Grossman optimization is reliable only if there are sufficient columns available to allow "mining" to optimum depth of the ore body and still allow the pit to break out at the surface within the confines of the columns.This author's approach is to create enough columns each side of the lateral limits of the ore to allow the pit to intersect the surface while still within the confines of the block model. Implementing the methods discussed by the authors helps to reduce the number of columns required to achieve this.

Jan 1, 1987

By J Ireland, S Rose

The main outcomes of mining grade control include defining the boundary between ore and waste and then categorising the ore according to which stockpile it should be sent. A typical workflow includes using general mine planning software (GMP) – such as SurpacTM, VulcanTM or CAE StudioTM – to create three-dimensional wireframes of mineralisation domains, which are used to flag the relevant samples of interest and constrain estimation during block modelling. Creating the wireframes is a time-consuming process, requiring reasonable software skills, patience and an eye for detail. The interpretations can be subjective; indeed, even the same geologist will give different shapes if presented with the same data at different times. The process can become particularly tedious when trying to carry out updates due to new data. It can also be difficult to test the effect of alternative interpretations or grade thresholds because of the time constraints in production.There are now several implicit modelling tools available, either as standalone programs or as add-on modules to existing GMP. In this paper, the authors develop a workflow using implicit modelling methods to show how grades and geology can be rapidly interpreted to provide effective domains for grade estimation. The paper includes case studies from open pit gold mines. The implicit modelling approach can save several days of interpretation work for each grade control drilling campaign.CITATION:Rose, S and Ireland, J, 2014. Implicit modelling applied to grade control data, in Proceedings Ninth International Mining Geology Conference 2014 , pp 115–122 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By T Elkington, A Finch

The theory of constraints (TOC) is a business improvement method that focuses on exploiting a business’s bottleneck to deliver the highest possible profit. Early applications were mostly in the manufacturing industry; however, the theory in itself is completely generic and has now been applied widely in other industries such as services, retail, software and distribution, amongst others. The intent of the approach is attractive – it focuses on the ‘silver bullet’ rather than ‘death by a hundred projects’, and it focuses on growth rather than cost cutting. Application within the mining industry has been limited to date, although there are a few applications emerging. This paper discusses how TOC can be applied to maximise value during the project planning phase and how to maximise profits when the mine is operational. The paper uses two case studies to illustrate the approach. Case study 1 uses the approach to improve tactical mine planning, which delivers an increase in revenue of 58 per cent. The second case study is a strategic mine planning example that delivers an increase in value of 77 per cent.CITATION:Finch, A and Elkington, T, 2014. Application of the theory of constraints to strategic and tactical mine planning, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 129–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By J F. C L Costa, J C. Koppe

It is recognised by the major international codes that resource classification involves the interaction of numerous qualitative and quantitative criteria such as data quality, geological and grade continuity, etc. However, the difficulty in quantifying the degree of uncertainty associated with mineral resources estimation has led to the creation of a large suite of methodologies, terms and definitions, with almost every mining company having its own set of standards. It is also intuitively known that several traditionally used methods to evaluate resources do not take into account the spatial continuity of the grades, being unable to provide a reliable measure of the error associated with their estimates. Since they do not provide an error assessment, these methods are inappropriate to assess local or global uncertainty associated with an estimate. Faced with these problems, this work aims at developing a methodology for either quantitative or qualitative analysis of mineral resources estimation, through incorporation of uncertainty and the correct definition of the associated risk or error. The proposed methodology includes the development of a software code incorporating all the main classification techniques used by the mineral industry. A comprehensive study about each technique was conducted allowing a comparison of the parameters affecting mineral inventory assessment. A case study was conducted with a typical iron ore deposit data set from the Conceitpo mine of the Itabira Complex in the Iron Quadrangle, Brazil. The results showed the specific limitations of each classification system and the influence in selecting their key parameters, always based on subjective choices.

Jan 1, 2009

By Houlihan RN, Landau J

A reciprocating plate column is described in which two sets of perforated plates are mounted alternately on two shafts and are reciprocated with a phase difference of 1800 between them. It is shown that such a column is mechanically superior to the previously proposed types: under practical operating conditions the pressure fluctuations at the base of the column are only a small fraction of the static head. Furthermore, mass transfer experiments with the system tributyl phosphate in kerosene- acid aqueous solutions of uranyl nitrate show that both high specific throughputs and reason- ably good efficiencies can be attained in this type of column. A comparison with the more conventional extraction equipment (mixer -settlers, pulsed columns) on the basis of residence time per equilibrium stage indicates the potential of reciprocating plate columns in hydrometallurg- ical application, especially in which the requirements of separation efficiency are modest while the scale of operation is large.

Jan 1, 1975

By G Yeowart, P D. Munro

The Prominent Hill copper-gold concentrator of OZ Minerals Limited in South Australia was built in 2008 and commenced commercial production in early 2009. It has a design ore throughput of eight million tonnes per year (Mt/yr). While the flow sheet has many items in common with other plants treating ores from iron oxide-hosted copper-gold deposits, the Prominent Hill concentrator also has some unique features. Plant design has been based on a 'template' of the very successful Ernest Henry concentrator. Initial options considered for processing Prominent Hill copper-gold ore are briefly examined as well as potential complications arising from the presence of a considerable tonnage of 'gold-only' material present in the deposit. Metallurgical test work and the subsequent decisions leading to the selection of a conventional crushing, semi-autogenous grinding (SAG) and rougher flotation circuit is discussed. One particular difference with other plants treating this ore type is that metallurgical tests and mineralogical studies identified that rougher concentrate had to be reground to a P80 of 20 - 25 microns or finer for adequate liberation of fluorine-bearing minerals. Subsequent satisfactory separation of fluorine-rich gangue material from the valuable copper sulfides requires highly efficient cleaner flotation to make a commercial quality copper-gold concentrate. Xstrata Technology's IsaMillÖ and Jameson Cell technologies developed to meet similar taxing fine grinding and flotation duties for the treatment of the refractory zinc-lead-silver ores of the Carpentaria-Mount Isa Mineral Province were selected for regrinding and cleaner flotation. Plant design has features aiding ergonomics for ease of operation and maintenance not commonly seen in recent projects with large sulfide flotation concentrators.

Jan 1, 2009

By Bellairs P, Stewart JC

On 20 December 1983 at 8.40am blast- hole 57 of Blast RN177 prematurely detonated follwed by a violent deflagration of blast- hole 59 at 10.40am. The blastholes were 380mm diameter drilled in black pyritic Mt McRae shale. The blastholes were loaded with ANFO and primed. Blasthole 57 was stemmed and blasthole 59 was not. A poss- ible mechanism which could lead to such a detonation is described. preliminary tests showed the top 5m of a bench had the highest temperature which could not be influenced by a range of treat -ments. Small scale laboratory tests show- ed that zinc oxide (ZnO) and magnesium carbonate (Mg2CO3) inhibited the reaction. A series of tests using AN with and without inhibitors loaded into the collars of blast -holes drilled in the top 6m of the bench and unstemmed is described. An analysis of the time to reaction of the holes loaded with AN against temperature shows that the decomposition of the AN in contact with the black pyritic shale is probably a sulphuric acid catalysed react- ion. All the inhibitors tested can neut- ralise the sulphuric acid in the shale. 10% ZnO appears to be an effective inhibitor of the reaction providing the AN/ZnO (90/10) is kept out of contact with surface material whose temperature can be as high as 60¦C in summer. It is concluded that ANFO/ZnO (90/ 10) should be now tested in stemmed holes.

Jan 1, 1986

By D Kentwell

This extended abstract and associated presentation provide a series of real examples of the complex interactions between the numerous input parameters, both geological and mathematical, that are required for resource estimation. Many of these parameters can contain a large degree of uncertainty at the initial resource stage. The resource tonnages and grades at economic cut offs of some types of deposits are relatively robust to these initial uncertainties while others exhibit significant sensitivity. In some cases, changes in parameters can result in counter-intuitive outcomes. Grades and confidence levels are inseparable; as the parameters change the confidence changes and so does the grade estimate. The extended abstract and associated presentation also discuss the question of whether or not a single solution is still an acceptable outcome for an estimate or if even a set of simulations based on a single fixed set of parameters is acceptable.CITATION: Kentwell, D, 2018. Sensitive dependence on initial conditions in resource estimation, in Proceedings Complex Orebodies Conference 2018, pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By V Rasouli, G Cavanough, A Mokaramian

The sampling time, the costs and its quality are the three factors that determine the best method of drilling in mineral exploration. The two principal methods of reverse circulation (RC) and diamond core drilling are often used in combination by mine operators. RC is used for drilling shallow holes and in-pit grade control, and core drilling for deeper holes to identify future resources. The RC method is faster and more flexible than coring and provides virtually uncontaminated cuttings (ranges from dust to 25 mm chips) to the surface cyclone suitable for geochemical anomalies. The diamond coring produces core samples to increase the level of geological knowledge and the 3D extension and distribution of the orebody. However, both of these methods are subjected to certain limitations and inefficiencies in reaching deeper depths and drilling complex hole geometries. Examples of such shortcomings include the inability to provide enough air pressure for RC drilling and high friction between drill pipe and the hole wall in diamond core drilling.Considering that delivering large volume of reliable samples from deep zones to the surface in shortest possible time is of paramount importance in mineral exploration, and assuming that obtaining core samples over whole overburden is not always essential, then drilling small size holes as fast as possible and delivering the small chip samples to the surface would be a good alternative with several advantages over conventional drilling methods for deep hard rocks mineral exploration. As a result, the use of coiled tube (CT) drilling technology has been proposed recently for such applications. CT is a continuous length of ductile steel or composite tube stored and transported on a large reel; and allows fast drilling by eliminating the connection time and providing continuous circulation during drilling. This enables quick access to the zone of interest to collect the cuttings or obtain core samples. CT is advantageous particularly in drilling directional boreholes and multi-laterals. In this paper, feasibility of using CT delivering reliable samples is discussed for deep mineral exploration. In addition, recent developments and practices are presented that make CT a reliable drilling technology to drill cheaper, faster and deeper and to deliver more continuous and reliable data and samples from deep formations.CITATION:Mokaramian, A, Rasouli, V and Cavanough, G, 2012. Quality sampling using coiled tubing drilling in deep mineral exploration, in Proceedings Sampling 2012 , pp 73-80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

Sishen uses a state-of-the-art tracking system to track material from its position in blast blocks through various stockpiles and crushers. Qualities are blended directly to the crusher as opposed to blending from stockpiles. This poses an interesting challenge to the planning department to simulate these conditions. The software used in these simulations are Whittle 4X and Maximiser for long-term planning, Xpac for medium-term planning and Mine Works Planner for short-term planning. Geological models and mine design layouts utilise Surpac. Sishen introduced Xpac a number of years ago; the system has developed and changed over the years. With the Sishen Expansion Project (SEP), which aims to utilise low-grade material, major changes to the planning process have to occur. SEP requires that the mine have two different plants, which utilise two different ROM feeds and have different beneficiation curves. Xpac is used to produce a rolling 18-month plan, which is as close to actual operations as possible. In order to do this, the simulations have to take into account the plants beneficiation curves, stockpile movements, hauling distance and equipment needs. On top of this, the schedule has to continually consider specifications for Fe and the contaminants. Plant yields also have to be kept within a certain bandwidth. Xpac is used to simulate the above parameters, as well as generate the raw data required to produce a mine budget. The paper will also show how the 18-month planning process and subsequent planning processes are measured and aligned. Xpac has proved to be an excellent tool to achieve these goals.

Jan 1, 2005

By A Gibbs

The mining sector has been a leader in investing in safety improvement initiatives, yet relatively few mining organisations can accurately track the positive effects of these initiatives or identify areas that may require more attention. The consequences of not taking safety seriously are severe, and unfortunately injuries and fatalities are continuing to occur across the mining sector (Brady, 2019). There is a tendency to turn to lag indicators such as All Injury Frequency Rate (AIFR), Total Recordable Injury Frequency Rate (TRIFR), and Lost Time Injury Frequency Rate (LTIFR) to track these outcomes. As outlined below these approaches are inherently flawed and a renewed focus is needed on indicators within the control of leaders, indicators that have high predictive validity for future events and data that is used in a way to enable learning and change.

May 5, 2022

By K Biegaj, S C. Dominy

A high-nugget effect and presence of coarse gold characterises many styles of gold mineralisation. The effective sampling of these deposits is often difficult because of the relatively low concentrations involved and erratic nature of the gold or other minerals. Geometric and/or metallurgical complexities often compound this effect. Underground development, in-fill drilling and bulk sampling/trial mining are generally required to delineate Ore Reserves. Similarly expensive definition strategies often apply to surface mining in complex orebodies of gold and other minerals, including precious stones. Development, particularly winzing is a historical technique that was used to gather geological, grade and metallurgical data during underground and near-surface exploration. It permits access to the mineralised structure below the surface datum to determine viability. Winzing has always been considered an arduous and dangerous task. Modern winzing technology has led to the development of the Mobile Supersucker – essentially a giant vacuum cleaner with underground and surface capabilities. By the elimination of shovel-loaded blasted winze material into a kibble and hoisting, this system permits safe and highly efficient winzing activities, and allows the collection of bulk samples for grade and metallurgical evaluation, as well as access to the mineralisation for geological and geotechnical mapping. Bulk samples from horizontal development have long been collected to help define mineable grade via pilot processing. However, when defining blocks below current development, there has been over-reliance on ineffective ‘small sample’ drill data. The Mobile Supersucker permits the development of winzes and off-winze sub-levels. These provide critical information to a mine technical team when trying to justify capital to go deeper or commence or deepen an existing open pit. CITATION: Biegaj, K and Dominy, S C, 2018. Lowering risk in complex mineralisation: application of mobile supersucker development, in Proceedings Complex Orebodies Conference 2018, pp 113–115 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Willis G. M

Preliminary experiments have shown that, when used in a fusedchloride electrolyte, titanium carbide anodes dissolve yielding lower titanium chlorides which nlay be electrolysed in situ to produce a cathode deposit of pure titanium metal. The anode residues are easily withdrawn from the cell. Further experiments have established the operating conditions for maximum efficiency in the process.The process is essentially two-stage, viz.: (1) titanium carbide production, (2) electrolysis producing metal. Power requirements appear to be moderate and this fact, combine·d with the simplicity of the process make it attractive as a possible method for the production of titanium.INTRODUCTIONDue to the high reactivity of titanium and its, affinity for oxygen and nitrogen, the extraction of this metal generally involves the use of halide. compounds as intermediates. For instance, magnesium reduction of titanium tetrachloride is the basis of the well established Kroll process and electrolysis of the lower chlorides in a molten salt bath has been proposed by Cordner and Worner (1951, p. 358) and others (Brenner and Senderoff, 1952, 223C; The TitaI Company (Inc.), 1952) as means of production of the metal. Thedifficulty of preparation of these compounds prompted a search for an alternative extraction process. The fact that aluminium, an equally reactive metal, has been prepared by electrolysis using aluminium alloy anodes suggested the possibility of a similar process for titanium production.The Titan Company (Inc.) (1952) has patented the use of crude titanium metal anode, but it was thought possible that a metallic compound, such as the carbide, could be used for this purpose. Although Lorenz and Kaufler (1909) suggested the use of carbide anodes for metal production, no...

Jan 1, 1956

Through the stress synthesis of many examples of macrostructure in the middle of China, it can be concluded that in the middle of Chinesetectonics there are two compression-torsion-forces, one of which ( from NW to SE ) came from the northwest side of Aerjinshan abyssal and giant fault("F1A", see Fig.7,8,9 ); the other (from S to N ) came from the south side of the north piedmontal fault of Kunlunshan-the south piedmontal fault of Qinlingshan ("F2K-F2Q", see Fig-7,829 ).Owing to the two compression torsion forces a new special type of structure named rotation-apart structure occurred from Chaidamu basin to Hebai, Henan, Anhui plain,from Caledonian movement, Hercynian movement,Yenshan movement to Himalayan movement, step by step In the north of Qilianshan during the late Caledonian movement: during the Hercynian movement it extended into a vast area including the Chaidamu basin and Eerduosi basin; during the Yenshan movement it spread over the whole area of Helanshan,Eerduosi basin and Hebai , Henan, Anhui plain. In the period of Himalayan movement all these structures revived .The rotation-apart structure controlled the distribution of all mineral deposits and also were the mineralizing structures.The relation between these rotation-apart structure and earthquakes is very close.

Jan 1, 1990

By S DeKruijff

The Mount Isa Mines Copper Mine in Mount Isa started producing copper in 1966. The Copper Mine gradually increased production rates to nearly six million tonnes per year. Over the last three years the mine has been in a gradual ramp down due to the reduction of primary ore sources and head grade. The majority of ore sources are predominantly in pillar retreat sequences bounded by multiple fill masses. There also a substantial lower grade resource delineated to the south of the main orebody. These remaining ore sources present significant engineering challenges to obtain a safe and cost-effective extraction. Stope designs have become increasingly complex and require additional engineering and operations input and analysis. This paper describes the major planning and operational challenges and issues associated with the stope design and extraction of an orebody in the later stages of mine life.

Jan 1, 2000

By R Lau

The fire safety design for road tunnels includes the following aspects: active systems, passive provisions and operational procedures. The active systems include the smoke control system, fire suppression system, detection system and fire fighter’s assistance systems. Passive provisions include escape passages, fire separation and fire resistance systems. The operational procedures refer to fire fighter access, reporting and alerts, evacuation processes and crowd control.Currently, these systems are typically designed by different designers or teams. These systems are intended to work together in a coordinated manner to provide the desired safety outcome. However, in practice, this is not always happening. The fire engineering process is supposed to bring together all these aspects and arrive at an integrated safety system. The fi re engineering process in practice is not integrating the design with the practice or reality and is thus arriving at less than desirably efficient safety systems.The example of design inputs shows how disconnected each system design basis is. The smoke control system design is based on the design fire size. The performance of the smoke control system is to achieve a smoke free environment for a defined space for a particular fire size – the design fire. The fire suppression system – most commonly sprinklers or deluge systems, is designed according to codes and to achieve a certain water discharge rate. The fire detection system is designed to detect temperature rise/rate of rise and perhaps density of smoke. Fire separation is determined to provide a certain period of service – mostly for structural elements. Escape route size and location is determined mostly by code compliance. Evacuation procedures are determined by Authority operational requirements rather than human behaviour.To arrive at an integrated fire safety system, the design basis and performances must be coordinated. An approach using fire scenarios would ensure all systems are designed to a common performance requirement. This paper will discuss how the current design approach outcomes compared with a fire scenario approach. More effective and efficient fire safety systems would require the stake holders to understand the implication of this approach and to embrace this through the fire engineering process.

Mar 8, 2011

By F Tang, Ö K. Büyükuslu, M Baben, S Petersen

GTT-Technologies’ ChemApp for Python was developed to provide a powerful, easy to use interface to ChemApp for a programming language highly popular with scientists and engineers. It is used, for instance, by GTT to develop program modules such as the CALPHAD Optimiser for the FactSage™ software, by customers to move from interactive FactSage calculations to perform versatile scripting with Python, and by GTT and its partners in research projects in the area of materials informatics. Computational thermochemistry is fundamental for advancing sustainable metallurgy and creating new alloy compositions for engineering applications. Materials informatics involves handling vast amounts of data and complex workflows. GTT’s approach uses ChemApp for Python and the FactSage thermodynamic databases to design recyclable alloys from the start, incorporating a higher percentage of scraps while aiming to simplify the workflows to simulate material design steps. Challenges arise due to recycling scraps, introducing more elements for consideration. CALPHAD-based databases accurately cover materials from primary metallurgy, but additional data for minority and critical elements is crucial for precise computational modelling. GTT combines machine learning-based ab-initio databases with traditional CALPHAD databases to cover the complete chemical space with appropriate accuracy. The design of a hardfacing alloy through a high-throughput materials informatics approach is used as a demonstrator of the current possibilities.

Jun 19, 2024

Study on Preparation and Gel Performance of High Purity Montmorillonite In order to research the colloidal and thixotropic performance of the inorganic gel prepared by high purity montmorillonite, this study uses the moderate grade bentonite ores from Weifang (China) as raw material. Two-stage hydrocyclone classification was applied to obtain the high purity montmorillonite with its content of 94.8 per cent. In contrast to other methods of montmorillonite purification, two-stage purification by hydroclone has the advantages of larger throughput and easily achieving auto-control in industry, and purified products with different montmorillonite content can be obtained by this method. And then the inorganic gel was prepared by the prepared high purity montmorillonite and its colloidal and thixotropic performances by measuring the flowability and thixotropy were further studies. Research results show that the inorganic gel has plastic body liquidity, the viscosity decreases with the increase of the shear rate, the static and dynamic shearing stress values are 33.98 Pa and 91.89 Pa, respectively, and the thixotropic value is 95.2 dyne+s/cm2, which indicates that it has preferable colloidal and thixotropic performance. Montmorillonite inorganic gel prepared by bentonite with high montmorillonite content and low-layer charge has better gel performance.

Sep 13, 2010

By J Sykes, W Treasure, A Saleem, A Trench, S Ulrich, R S. Davies

Below-ground technical complexity remains a traditional source of project challenge. Above-ground challenges then augment this complexity, including in the domain of commodity marketing. All challenges must be solved to produce quality, saleable, ex-mine product. The situation is further complicated in that technical complexities are not independent of each other, so complexity is best regarded as a system rather than a series of isolated factors. Additional above-ground challenges to mining projects are also increasingly sourced from societal and environmental factors, locally and globally. These challenges not only confer project complexity, but have their source in larger, global wicked problems. Finally, financing and resourcing of projects represents an ever-present challenge for all but the highest-quality mineral deposits. CITATION: Trench, A, Davies, R S, Saleem, A, Sykes, J, Treasure, W and Ulrich, S, 2018. On the sources of complexity in contemporary and future mining projects, in Proceedings Complex Orebodies Conference 2018, pp 65–66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018