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By T Ye Koltunova an, L A. Otrozhdyonnova

This paper presents the results of studies on the development of an efficient non-cyanide technology for processing massive, finely disseminated, copper-zinc ores of the Urals deposits. Copper is mainly represented by chalcopyrite and zinc û by sphalerite. The main ore mineral is pyrite, with its content in ores varying from 50 to 80 per cent. At the present time, separation of copper concentrate at the Urals concentrating plants is achieved in a lime medium by non-cyanide technology using sodium sulfide and zinc sulfite as depressors of zinc and iron sulfides and butyl xanthate as the collector. Copper content in copper concentrates amounts to 15 - 17 per cent; considerable losses of zinc are associated with copper concentrate and final tailings. Various collectors were tested during the studies: xanthates and aerofloats with different lengths of hydrocarbon radicals, thionocarbamates, Aerofine 3418A of Cytec Industries, reagent S-703G of Mineral Reagents Int, and modifiers û sulfur dioxide, sodium sulfide and zinc sulfite, with a pH of the medium varying from 5 to 12. Optimum results of copper concentrate separation were achieved in a weakly acidic medium using S-703G as the collector and sulfur dioxide and zinc sulfite as modifiers. The copper content in the copper concentrate was increased by 4.8 per cent. Total copper recovery into the copper concentrate and zinc recovery into the zinc concentrate exceeded five per cent.

Jan 1, 2005

By M M. Tarshan

Separator performance is evaluated by the so-called separation efficiency. The concept of efficiency in mineral dressing operations must be interpreted with considerable care. Although qualitative use of term efficiency is valid and useful, difficulties arise in expressing it quantitatively because two conflicting criteria, grade and recovery are normally involved in its evaluation. It is undesirable to express efficiency as a single value, even though this is frequently done in practice, since there are strictly speaking an infinite number of combinations of grade and recovery that can give that one value. Inefficiencies in processes can be attributed to three broad sources: mineral limitations as represented by the separability curves, equipment limitations (which prevent the maximum separation indicated by the separability curves), and human failure to minimise these inefficiencies. In the present paper, the efficiency of a two-constituent separation process has been examined. The separation process has been evaluated by comparing the sharpness factor of the actual, the absolutely efficient and the absolutely inefficient operations.

Jan 1, 2000

During the last century Allis-Chalmers has supplied many screens of various types to industry, from revolving screens to the large capacity highly efficient screen available today. The features incorporated over these years in horizontal and inclined screens are varied and numerous and include many innovations such as tri-and bi-sloped screen decks. Today the emphasis is on wide vibrating screens with good "G" value, with large "throw", to achieve high capacity. Larger screens lead the way to treating a somewhat neglected area of mining operations - that of concentrator mine flotation tailings to allow effective transportation and stacking by conveyor belt. The benefits from a cost, water saving and environment view point are discussed in this paper.

Jan 1, 1984

By Colquhoun L

Flooding velocities were measured in a laboratory column (96 mm 4) provided with both bottom and side air entry Packings used were 6 mm glass rings and spheres and -16 +8 mm coke. Results showed that when air was introduced through side nozzles flooding velocities were much higher than those obtained when air was introduced at the bottom of the column. Significance of the results and application to blast furnace flooding is discussed from the viewpoint of assymmetric gas flow.

Jan 1, 1975

The 1980's has seen a revolution in gold mine developments in Australasia. We are witnessing a near ten fold increase in all phases of gold mine development ranging from exploration through to production. Ounces produced have yet to mirror this activity but have increased from a low point of 600,000 in 1980 to 1,800,000 ounces in 1985 in Australia alone. In 1980 the region had less than 10 gold mines, yet 14 new mines started production in 1985 and as many as 28 might start up in the next 18 months. Developing gold mines in the 1980's in Australasia has not been the easiest of jobs, yet the great number of new developments suggest that we have entered a new era that will rank in history along with the 1850's, 1890's and 1930's as high points.Within- our Australasian region two very distinctive styles of gold deposits are being discovered and developed. On the Australian mainland the new mines are in geologically old rocks and are mostly the low grade haloes surrounding worked out high grade deposits. Most are limited life open pit operations depending on recent innovative carbon-in-pulp or heap leach technology. In the Pacific Islands region the style of discoveries are geologically recent, large bulk-low-grade deposits often geologically analogous to porphyry copper deposits. These deposits are typically 10 to 20 times larger than those being proved up on the Australian mainland.

Jan 1, 1986

By N B. McCaffrey, V Glenn, C Johns, P D. Erskine, A T. Fletcher

"Underground coal mining is the dominant method of extracting thermal and coking coal in the southern and western coalfields of New South Wales. Monitoring mining-related subsidence forms an important component of environmental impact assessments and subsidence management plans, particularly when there are conflicts between the interests and requirements of mining and environment and community groups. However, there are few specific guidelines for monitoring the impacts of subsidence on terrestrial and aquatic ecosystems, leading to inconsistent policy approaches and highly variable abilities of monitoring programs to accurately detect biological change.This paper highlights the use of a conceptual framework to guide the development of a long-term ecological monitoring program at an underground coalmine in the Western Blue Mountains, New South Wales. Two pilot studies are described: determining the level of observer agreement to assess the condition of a vulnerable tree species (Capertee Stringybark) comparing field sampling methods for detecting a rare heath shrub, Epacris muelleri, using a power analysis to determine sampling intensity requirements.These examples demonstrate that investment in initial pilot studies to test different monitoring approaches can have long-term benefits for stakeholders by more confidently being able to detect potential impacts.CITATION:McCaffrey, N?B,?Glenn, V, Erskine, P?D, Johns,?C?and Fletcher, A?T, 2014. Detecting long-term ecological impacts of subsidence from underground coal mining – a tale of two pilot tests, in Proceedings Life-of-Mine 2014, pp 139–152 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By A M. Ebbels

"Underground mine scheduling decision-making has been based on production requirements, equipment productivities and the mine planner’s instincts on the best scheduling strategy for the mine to optimise the net present value (NPV) of a project.In the last few years, innovative software has been developed to optimise underground schedules based on NPV. The schedule optimisation tool (SOT) allows the user to set up scenarios based on grade, metal content, capital and operating costs.This paper discusses the results of two case studies undertaken using the SOT software to optimise the NPV of the projects.In each case study, the SOT software has been applied in two ways:using the original mine planner’s scenario and determining whether the NPV could be improved by changing resource capacitieschanging the scheduling goals to determine whether a different mining strategy would have a better NPV outcome.The outcomes of the case studies demonstrate that the mine layout and design were contributing factors to the overall improvement of the NPV and that SOT has a more noticeable impact on the NPV of projects where less sequence constraints are required, such as geotechnical sequencing and access development.CITATION:Ebbels, A M, 2016. Optimising underground mining strategies, in Proceedings Project Evaluation 2016, pp 60–65 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By Olson H, Kincaid R

The marine portion of the Pacific Basin and Rim constitutes a significant part of the world's surface in which the mineral resources are virtually undeveloped. Indications of substantial resources have resulted in speculation and uncertainty with regard to their potential in the near term. The main issues are centered on the markets for the resource materials, the technology needs for their recovery, and the possible impacts of their development on the environment. While the governments of Japan, France, the Soviet Union, India, China, and Korea are financing new programs in deep ocean mining, the US is consolidating its early leadership by the continuation of NOAA's authority under the Deep Seabed Hard Mineral Resources Act and the Sea Grant Act, Interior's authority under the outer Continental Shelf Lands Act, and by the development of a new Marine Minerals Technology Center within the Department of Interior's mineral institutes program, managed by the U.S. Bureau of Mines. The Center has a Continental Shelf Division (CSD) located in Mississippi, and an Oceans Basin Division (OBD) located in Hawaii. Research and training in the divisions is directed toward the practical aspects of mineral recovery from the nearshore and deep ocean environments with a strong bias for the OBD toward industrial and international cooperative programs in the Pacific Basin and Rim. In terms of resource development, the marine minerals in the Pacific Basin may be favored in some cases, in competition with land sources, by political and environmental considerations.

Jan 1, 1990

A number of cooperative studies have been carried out as preliminary work for drafting a standard for application of granulated slag sand for concrete, and the following conclusions were reached 1 The ten kinds of granulated slag sands pro- duced in Japan satisfy the national standard for fine aggregate in terms of physical and chemical properties. 2 Mortar and concrete tests conducted with granulated slag sand revealed that, although with slight differences in the extent, gran- ulated slag sands used in these tests were applicable'as fine aggregate for concrete, 3 The pumpability test by a concrete pump carried out on concrete with two kinds of now commercially available granulated slag sand demonstrated that the pump pressure feeding is applicable in the same manner as in the case of ordinary concrete. These tests permitted' preparation of a draft standard for application of granulated slag sand, and the results formed the first step toward utilizing this material as a sub- stitute for natural sand.

Jan 1, 1979

By Sobek S, Lotzien RM

Although the conventional procedures for designing agitator flotation plants are well-known and reliable, little experience for designing modem pneumatic flotation plants has been gained up to now. A reliable procedure originating from graphic methods for the design of distillation columns is presented. Examples demonstrate on laboratory and semi-technical scale the application of this extremely practical method for designing a fly ash and a magnesite flotation plant.

Jan 1, 1993

By KeBler H-W, Seeliger A

Vibration analysis for diagnosis of machines is a powerful instrument for condition monitoring. Especially for diagnosis of antifriction bearings various equipment and techniques have been developed and are available. The envelope analysis is the most reliable method for bearing diagnosis. Different bearing failures lead to different patterns of the envelope spectrum. Checking the amplitudes of characteristic bearing frequencies is mostly not sufficient for a reliable diagnosis. Therefore human experts compare the pattern of the spectrum with typical patterns of bearing defects. In this paper a diagnosis system is presented which imitates this action of human experts. Using a neural net the system not only distinguishes typical bearing defects but also detects unbalance, beating of disengaged machine parts and other kinds of machine failures.

Jan 1, 1995

By Pandey A. K, Srivastava A, Das A

Drilling and blasting constitute important activity in mining operations and account for around 20% of the total excavation cost. The utilization coefficient of energy for explosions of the fragmentation type is hardly 15 to 2035 and an enhancement in this is possible only through optimization of blast design. Designing a 'blast is a complex planning task, which for optimum results calls for matching the energy level of the explosive, rock properties and bench geometry. Optimum blast design needs a comprehensive study and an objective analysis of the intersecting elements. A cost optimised approach is often adopted with due consideration for all the cost sectors viz., drilling, blasting, loading, hauling dumping, and primary crushing, contributing to the overall miring cost. The present study deals with a performance prediction model which predicts the optimum burden for an explosive system in a given rock type to produce a certain desired fragment size. The model is framed on the inputs : shovel size, drill size, unit cost of drilling, bench dimensions, rock density, bond index, unit cost of explosive, maximum work potential. The model has been extended to compute the drilling and blasting costs for an assumed size of the bench to be blasted per round, so as to arrive at the overall cost optimization from a number of explosive systems. A comparative cost calculation with different explosive systems has been presented for a typical iron ore mine in India.

Jan 1, 1990

By Porter I

Rock mass classification systems have emerged as a powerful tool which can be used for assessing ground conditions and determining support requirements in underground mines. They should not be used as a substitute for complete engineering design, but rather as a supplement to observational methods and analytical study. In general, the use of rock mass classification is attractive, but each classification system has various deficiencies. Use of any particular system should be made only with knowledge of that systems limitations. It is desirable to employ a number of systems and design methods which will allow for comparison and lead to a better understanding of the rock mass condition.The Rock Mass Quality system (Q-System), developed by the Norwegian Geotechnical Institute, and the Rock Mass Rating (RMR) System, Bieniawski, were designed primarily for civil engineering structures. Laubscher et al (1978) further developed the RMR-system specifically for rock mechanics engineering in the mining industry. A method of stope design, which introduces a stability factor for the rock mass and compares this with hydraulic radius, was developed by Mathews et al (1981). This paper reviews the above systems by applying them to stability assessment of crown pillars in two Australian metal mines and provides a critical analysis of the various approaches. In particular each system will be analysed to determine its suitability for use in crown pillar design. The most suitable system(s) will form the basis for future development in crown pillar stability analysis.

Jan 1, 1994

Underground mines in Australia and worldwide are extending to greater depths. The effect of depth brings a number of challenges to mining engineers including geotechnical, ventilation, haulage and selection of mining method. The main effects of depth from a ventilation perspective are increased heat and humidity leading to reductions in productivity, occupational safety and health issues and the potential for fatalities. Numerous approaches have been undertaken over the years to mitigate against these effects. In this paper a review of various approaches to improving climatic conditions at a number of mine sites worldwide is undertaken. From these case studies it is argued that for mines at depth with the potential for a climate problem perhaps an alternative design philosophy to the established design philosophy should be utilised. In conclusion, the paper proposes some simple rules of thumb for use in mines with climate problems or the potential for climate problems.

Jan 1, 2008

Conventional blasthole sampling for grade control has acquired an extremely bad reputation for the last 50 years. The introduction of many sources of bias is a structural reality. Delimitation biases are devastating. Extraction biases are of great concern as well. Weighting biases aggravate an already bad situation. Furthermore, preparation biases are many. Some of these biases are due to the type of drilling machine that is used and are nearly unsolvable. Some of these biases are due to the sampling tools that are used and often unsatisfactory. Attempts to automate blasthole sampling at the drilling site have failed, not because it cannot be done, but mainly because it interferes with drilling productivity. As a result the miner most often rejects the idea after a few weeks of practice. Manual sampling of blasthole piles is a disaster for many reasons; some are related to the methodology, some to the selected sampling protocol, some to the training of operators, some to limited manpower available, and some to limited supervision. Furthermore, with blasthole sampling a time logistic problem is unsolvable as the miner wants the ore grade control geologist to make up his mind within two or three days at most; as a result not enough time is allowed for samplers, preparation facilities, laboratory, and resources department to perform a good job as everyone is working under unreasonable pressure. The economic impact of poor blasthole sampling for grade control has been vastly underestimated by mining companies. The resulting ore grade misclassification is responsible for severe reconciliation problems and massive financial losses every year. This paper suggests areas along this grim scenario where things can be greatly improved; however it is clear that too many problems are unsolvable. An alternative using reverse circulation drilling for grade control is suggested. A thorough analysis of the respective advantages and disadvantages for blasthole and reverse circulation drilling for grade control is presented in this paper.

Jan 1, 2008

By P Krauss, S Harpalani

Methane emitted from underground coal mines, along with ventilation air and known as ventilation air methane (VAM), constitutes the largest component of coal mine methane (CMM) emissions. Atmospheric methane, on the other hand, is a potent greenhouse gas with a significant adverse impact on the atmosphere. This has led to the development of various technological alternatives for its use as an energy fuel. Techniques involving oxidation of VAM, usually consisting of very low concentrations of methane, have been validated in the past. Prominent among these technologies are the thermal and catalytic flow reversal reactors, ancillary fuel technologies, lean fuel gas turbines, and concentrators and gasifiers. However, the efficiency of any VAM utilisation technique depends on the amount and concentration of methane in the ventilation exhaust air. Therefore, quantification of VAM emission from a coal mine is the first step towards identifying the most suitable technology for its utilisation for energy production. This paper presents an evaluation of the efficacy of VAM as an energy source. It provides details of a case study aimed at developing a technique to accurately quantify VAM emission from a coal mine. It further discusses the various VAM utilisation techniques available, and presents an economic evaluation of the alternatives. Based on the findings of the study, the most feasible method for VAM utilisation is identified for the mine. The paper summarises the procedure for quantifying VAM emissions and selecting the most suitable utilisation technique.

Jan 1, 2005

The treatment of nickel ores and concentrates and the subsequent processing to recover separate products of nickel and cobalt is one of the major interests at present in the mining industry. The increasing demand for nickel, and more recently also cobalt, has led to increased exploration for ore sources. Major discoveries have resulted in Canada and Australia. These deposits, as well as others already known, are presently being developed and the process technology tested and evaluated for applicability to the different mineralogical types - mainly sulphide, arsenide and oxide laterites. Concentrates may be treated by either hydro- or pyrometallurgical processes, while the nickel laterites are best suited to hydrometallurgical processing. However, if hydrometallurgy is used, once the ore or concentrate is leached the resultant solutions are then amenable to similar separation technologies for purification and recovery of high purity nickel and cobalt products. Solvent extraction, together with other separation processes such as precipitation, can produce high purity solutions of nickel and cobalt. The final products of these solutions may be nickel and cobalt cathodes, metal powders precipitates or salts, depending on the final process of electrowinning, hydrogen reduction, precipitation, or crystallisation Respectively.

Jan 1, 1996

By B D. Sowerby, N G. Cutmore

Improved process control can be achieved through the accurate and reliable on-line measurement of critical process parameters in real time. Over the past few decades on-line analysis techniques have been developed and applied in the mineral and energy industries for the measurement of process stream composition, mineralogy, particle size and flow rates. This has led to increased throughput and product quality while reducing processing costs and minimising emissions. The support of a sustainable mineral processing industry will require the further development of on-line analysis and control technologies. The application of developments in instrumentation combined with improved control strategies will lead to improvements in process efficiency resulting in large economic benefits to the industry, reduced energy usage and lower process emissions. There is a clear convergence of interests in being able to better measure and control minerals processing in terms of the triple bottom line of economic, social and environmental impacts. Technology is increasingly becoming available enabling measurement across the entire spectrum of minerals processing from mining to hydrometallurgy and pyrometallurgy. CSIRO is developing a range of these new technologies. A number of these developments are discussed in the present paper, namely: on-line particle size analysis and acoustic emission methods to enhance the control and optimisation of grinding circuits; on-line mineralogy of dry powders and slurries; on-line bulk elemental analysers for application on conveyor belts and in smelters; and the development of new sensing technologies for sorting base metal ores.

Jan 1, 2002

The provision of electrical power is an important consideration in project development. The first step to be taken in this area is to assess the power requirements of the project. The alternatives of laking a supply from a power authority or providing local generation can then be considered. This requires additional defmition of the probable characteristics of the supply.The availability of authority power in Australia is limited by the extent of the state power grids. Recent developments now allow these grids to be extended and their load capacity increased to meet major load increases at less cost than was previously possible.The options for local generation include diesel, gas turbine, steam, hydro, solar and wind, each having its particular performance characteristics and costs. The choice of fuel for diesel, gas turbine, and steam plant likewise involves consideration of a range of factors. The arrangements adopted for five recent Australian remote development projects indicate how some of these aspects influence the decision on power supply.

Jan 1, 1990

By Seedsman RW, Duncan Fama ME

Mine design procedures will be revolu- tionised by technological developments in computers, software, database construction and management, and numerical modelling programs. Developments in geotechnical databases will be required which utilize geological and geomechanical tests to supply appropriate input for numerical models. Techniques utilizing sedimentological and structural modelling are described. The capacity of current numerical models in mine design is outlined and a program for developing a fully integrated mine design package proposed.

Jan 1, 1987