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By Mazandarani M, Chabot L, Vichion K

Pitch-steering models have been developed for discretely advanced mining machines (such as heading machines and coal shearers) using small-angle geometry and there are illustrative examples of simulator predicted performance. Although simple linear models result from the analysis of open-based machines, sledge mounted machines require execution of a Linear Programming energy minimisation to determine the attitude of the machine base at each advance over the previously cut floor steps. An analytical approach is based on elastic beam concepts developed for such applications as longwall face conveyors, caterpillar tracked machines such as continuous miners and longhole drills. Simulation results for longhole drills show the expected performance of an automatic guidance system and the destabilizing effects of sensing deviation too far behind the drill bit. Certain drill bit boundary conditions are expected to assist TBM. steering studies in three dimensions.There is a real role in mining machine steering for the mathematical models used in flight simulators.

Jan 1, 1991

Throughout 1992 Pasminco conducted field trials of the Mobile Miner MM130 at Broken Hill. The goal was to develop the machine to achieve acceptable reliability and establish production rates.

Jan 1, 1993

By Yusuf R

Many heap and dump leaching processes involve competitive, complementary and sequential reactions between multiple minerals and reagents. A comprehensive model has been developed to deal with these complex chemical interactions which is based on diffusion control of the reaction rates. All of the mineralogical and chemical data are obtained from representative samples of the ore or the chemical literature. These properties have been incorporated in a general way, making the model applicable to a range of ore-process systems. The simulation is used to predict the absolute reaction rates and can be used before any leach tests are carried out on the ore itself. The applicability of the model and some tests of its validity are presented.

Jan 1, 1984

By Green GR

Description of two methods developed at Sulphide's Cockle Creek Plant as part of a site energy reduction program. The two case studies are:

Jan 1, 1985

By R Stimpson, B Johnson, B Hesse

During a period of twelve months between FY18-19, a series of trials were conducted to compare production drilling accuracy using two different methodologies, and the subsequent impact this had on stope performance (dilution and recovery). Testing was conducted at a series of underground mines in Australia. The drill rig’s existing alignment processes were compared to a new technology system, with the following observations: • The new technology was proven to limit rig alignment error, thereby reducing average blasthole deviation, resulting in an increase in the number of holes drilled within tolerance by up to 160%. • The increased accuracy reduced stope dilution significantly by reducing over-break of subgrade ore, whilst also increasing drilled meters (faster stope-cycle time), reducing the bridged tonnes ratio, and facilitating the capture of previously uneconomical stopes. A cost-benefit analysis extrapolated from each of the trials showed the extent to which the new technology, when applied to production data, reduced average dilution, increased ore recovery as well as general drill and blast productivity. In one such trial, the new technology was proven to have reduced average dilution by net 45.4%, which if applied to a full year’s production data, would result in AUD8.2M additional ore recovered, with AUD4.5M less spent on wasted cost of haulage and processing of diluted ore. As a result, return per tonne would increase 22%, from AUD87 to AUD106. This improvement was maintained over the following 12 months – reducing average dilution from 22% in FY17 to 12.1% in FY19.

Mar 15, 2021

By A G. L Pratt

Operational readiness is a commonly used term in mining and many other industry settings. However, translating this term into a coherent scope of work that is practical and meaningful is a challenge faced by many mining projects. This inhibits the allocation of resources to the work and its completion. The problem is with understanding how the terminology applies to establishing a mining operation. Resolving this problem requires clarity around what operational readiness means for a mining project’s transition to operations and who owns the tasks of completing operational readiness. The motivation for resolution of this problem is in appreciating the consequences arising from any lack of clarity in definition of this task, the timing of the work, and ownership for its completion. In broad terms, these consequences amount to an erosion of value at a critical time for both the new mine and the company and shareholders. This situation often arises where operational readiness is not adequately addressed in project’s study phases. As a result, neither time, resources nor money are adequately provided to complete the work required. In other cases, operational readiness is sometimes assimilated with the delivery of the project’s physical assets by the project’s construction team, rather than aligned with the establishment of the operating team to deliver the desired operational outputs. This paper argues that operational readiness starts in a project’s study phases and flows through into the start of operations. The definition of operational readiness is discussed as a task, and a model for its planning and completion is presented. This discussion includes assigning ownership for operational readiness planning and delivery to the General Manager of a new operation and the operations leadership team, who are central to the success of this work. After all, the reputations of this leadership team depend on the performance of the operation in its first few years. The author’s work over the last 20 years, leading operational readiness programs and the preparation of feasibility studies for mining projects, has provided the insights and evolution of ideas that are central to this paper. Operational readiness is fundamentally directed at ensuring a new mining operation gets away to a successful start and builds a solid foundation for the future of the mine/operation/province. It requires clarity of purpose, ownership and coordination by people in the operating team, and their preparation of the requisite process definition and establishment of the significant relationships required for operations. Without its successful completion, it is unlikely the new operation will meet and sustain its start-up targets. This paper discusses a practical approach to operational readiness for mining projects.

Mar 29, 2023

By F Phillips, E Deucker, J Kato

It is challenging to determine the optimal mining strategy to maximise value when a mine plan includes mineralised material which does not meet the full cost of mining but has value exceeding the variable cost of mining (‘marginal material’). Mining too much marginal material dilutes the operation’s head grade and undermines profitability. Conversely, leaving too much metal behind fails to achieve the full value of the endowment. Finding the balance between the two will maximise value delivered from the asset. This dilemma has traditionally been approached by calculating a suite of cut-off grades to define the grade of material that meets economic targets for an orebody (or zone within) and should therefore be included in the mine plan. A problem with this approach is that individual mining blocks within the zone have different costs, value and confidence levels, with each having economic co-dependencies between them. Blocks of identical grade but different mining contexts will have distinctly different economic outcomes. For example: • a block may be a low-grade increment or shell around a higher-grade stope; • a block may be available to be mined when there is spare mining capacity; or • a block may defer access to significantly higher cash flow material. Each of these circumstances would result in different value from the blocks if included as part of the mine plan. Cut-off grades calculated as averages over zones of material, or in isolation from schedule-based information, are missing the entire mining context that determines the ultimate economic outcome of making a mining decision. There are tools and techniques available to address this for open pit mining, however underground mining has different nuances. There are more intricate economic and physical dependencies between potential ore blocks, and importantly, the decision to leave material in situ can be made at any time. The case study in this paper explores a new methodology for underground mining, targeted towards strategic planning applications. It examines whether the economic logic usually applied via cut-off calculations can be implemented in the schedule so that optimal economic decisions can be made on a block-by-block basis, taking into account the mining context of the block, with the objective to maximise asset value. The results of the case study scenarios in Table 1 demonstrate the magnitude of the potential improvement in NPV that can be attained by a block by block valuation approach

Mar 15, 2021

Coal Mining machinery has undergone enormous changes in design and complexity of controls in the past 10 years. Specialised, high productivity equipment has been manufactured in Australia, in sufficient volume, to satisfy the local mullet needs.Local manufacturers face greater challenges from overseas competition, as well as increased customer demands to improve machine performance, productivity, quality, reliability and safety. In order to meet these demands now and in the future, it will be necessary to review work practises, and restructure production and quality systems to incorporate the latest principles and philosophies.

Jan 1, 1991

By Komosa T, Muir D. M

Adequate levels of dissolved oxygen are essential for efficient gold dissolu- tion. The actual levels in plantpuips can be seriously reduced by the presence of oxygen consuming reactive minerals, and reduced oxygen solubility in saline water. The rate of gold dissolution is then limited by oxygen availability rather than cyanide. Ion selective electrode dissolved oxygen meters can give an effective indication of the relative oxygen saturation, but they are not able to give meaningful values of dissolved oxygen in saline water, without custom calibration curves. When the dissolved oxygen concentration is rate limiting, the addition of oxygen or peroxide can improve gold leaching kinetics as well as reduce cyanide consumption.

Jan 1, 1991

Market forces, particularly iron ore prices, demand that plant operators achieve higher throughput in the worldÆs iron ore beneficiation plants without compromising yields or efficiency. This means that production cost per ton is of paramount importance and that all major pieces of Processing Equipment have come under close scrutiny to improve throughput at their most efficient performance levels and for the longest possible continuous running time. Without doubt the use of modern engineering standards and materials of construction has contributed to matching these throughput, efficiency and availability demands. However, often not enough attention is paid to the so called æinsignificant elementsÆ connecting this metallurgical equipment, such as chutes, pipes or other conveying systems, and particularly to the sufficient protection of their wearing surfaces. The result can be an unplanned and expensive outage caused by the wear related failure of such components. This paper will discuss:the theory of wear and the multiple factors of material and design that contribute to a reduction in wear; and the combinations of modern wear resistant materials available to todayÆs engineer and how, by intelligent selection and correct application, plant availability can be optimised. Examples outlining how these principles have been applied in South Africa showing some improvements leading to increased plant availability.

Jan 1, 2002

By James S. E

Financial risk of environmental problems is the key to many important business decisions within the mining industry. Massive uncertainty makes it difficult to choose a strategy for managing environmental problems to reduce corporate financial exposure to environmental impairment. A correct and practical method exists to clarify the risks and help make decisions. A case study on an insurance problem illustrates the method.The approach used is to translate existing data on environmental problems into probabilistic expressions of financial risk, and organise the expressions to reveal alternative solution strategies for the insurance problem.

Jan 1, 1993

Sampling and analysis of mineral deposits need to be executed without fear or favour of financial or personal impacts. Examples are given to illustrate the effects of departures, witting and unwitting, from correct use of appropriate techniques and/or equipment with emphasis on exploration and mining of porphyry copper deposits of the Pacific Rim. Some of the results of errors on the low and high sides of true value in exploration, resource or reserve estimations and in production caused by sampling and/or sample preparation mistakes, faulty practices, equipment and/or analysis are considered.

Jan 1, 2004

By Benson R. P

Building a new tunnel to accommodate CN North America's needs or double stacked container traffic for the next 100 years represents new and unprecedented challenges. Innovative approaches to contracting, especially the Negotiated Compressed Process (NCP), TBM design, project management, and the regulatory and approval process, were all required to deliver a new tunnel to meet the needs of CN North America within the approved completion schedule of 33 months compared to a traditional approach of 45 to 48 months. The NCP resulted in trimming a full 12 months from the project schedule with an anticipated saving of direct and indirect costs.

Jan 1, 1993

Key blocks occur on the surface of excavations and on the walls of the ornamental stones and limestone quarries due to the formation of joint planes, fissures, microfaults and quarrying operations. Movements of these key blocks have produced numerous important failures and are responsible for routine overbreak and rock falls accounting for great costs. The thrust of this work is to demonstrate how to delimit zones of poten- tial key blocks (danger zones) in the wall of Bani-Khalid quarry of lime- stone by using the block theory technique (stereographic projection). The final result of this study indicated that, there are three potential key blocks, the most critical one has been determined. To treat the problem, we sug- gest either to provide timely support to prevent the movement of this block, or to analyze it further in hopes that available friction on the faces will hold it safely in place.

Jan 1, 1989

By Allchurch P. D

At Perseverance a reserve of 45 million tonnes at 2% Ni was indicated by drilling. Holes were drilled in trellis pattern on section lines 61m apart to assess shallow mineralization. To explore at depth holes were spaced 122m apart, collared vertically, then allowed to deflect under controlled drilling conditions. The mineralization may be divided into the three homogeneous classes of soarsely disseminated, heavily dissem- inated and massive sulphides. In the standardised sampling and assaying procedures used to assess the deposit, attention was always paid to these fundamental ore types. All sampling and assaying processes were continuously monitored by checks. Sampling and sample preparation errors were small, to judge from the differences between results of original and check samples. Assaying errors, determined from analyses made by independent laboratories using different methods, slightly exceeded sampling errors. Comparison of underground core, c'iannel, and grab sampling, suggests that core sampling tends to undervalue.

Jan 1, 1976

This paper briefly reviews the history of mine haulage trucks. It reviews producti- vity limitations with respect to size or speed. Changing haul requirements once again create the need for more flexible mechanical drive power transmission equipment. The new equip- ment however is designed to provide extended life between overhauls as compared with previous mechanical transmissions.

Jan 1, 1981

An approximate rapid design system for tunnel liners and underground structures is presented which permits the effects of structure geometry and stiffness, rock quality in terms of its deformation modulus, and the applied system loading to be entered as data to produce direct designs conforming to stress limitations, optimum reinforcement requirements and restraints on section dimensions. An 'equivalent column' concept is introduced for modelling the rock mass in contact with the structure. Only the rock treatment is given in detail but the results of sensitivity analyses, with reference to rock quality, for a typical liner design are given and these results related to a number of empirical design approaches.

Jan 1, 1976

By Forster I, Thilo A, Dean AK

A prototype production tool capable of operation in the hole sizes (

Jan 1, 1988

By Saghafi A

Spoil piles are produced routinely in open cut coal mines. Spoil piles may contain waste coal and other carbonaceous horizons. Coal and carbonaceous materials react with oxygen in the atmosphere, producing heat. If the rate at which heat is generated is greater than the rate at which heat can be dissipated, the temperature of the spoil pile rises. If the heating remains unchecked, spontaneous combustion can occur. Spontaneous combustion poses significant safety, environmental and economic problems if it should become established in spoil piles. Using the basic features of self heating in spoil, the use of model is directed toward developing quantitative prediction of spontaneous combustion in open cut coal mine spoil Piles.

Jan 1, 1998

By A J. Moore

Blasting operations in open cut mines results in airblast, ground vibration and rock movement with the potential for wild flyrock. In some mines there is a trend towards blasting closer to established infrastructure as extraction boundaries alter with increased resource prices and changed economic circumstances. Mine infrastructure in close proximity to blasting has the potential to be damaged by ground vibration and wild flyrock especially. To provide guidance for the determination of appropriate buffer distances and blast specifications, this paper describes methodologies that may be used to determine the potential for damage to infrastructure by predicting:dynamic blast;near field ground vibration levels;dynamic blast strains induced in infrastructure by consideration of ground vibration,ground strain and response amplification;potential for damage by comparing induced strains with allowable working strainsfrom structure design codes and serviceability requirements; andflyrock throw distances based on models developed from flyrock investigations.This report demonstrates the use of strain prediction methodologies developed during Australian Coal Association Research Programme (ACARP) Project C14057 for infrastructure such as conveyor belts, transmission poles and towers, buildings and bridges.

Nov 8, 2011