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The discussion in this paper centres on examples of mining that are drawn mainly from the coal mining industry. The intention is to review the opportunities that exist for incorporating environmental planning into mining industry practice in New Zealand. The coal mining examples serve to make some general points which have some application for many types of mining.

Jan 1, 1981

By K Aikawa, M Ito, K Mitsuhashi, Y Ebisu, J V. Satur, I Park, N Hiroyoshi, T Suto

Copper concentration using flotation is becoming more difficult, because of an increase in ore complexity accompanied by smaller grain sizes of copper minerals than usual, requiring finer grinding in order to liberate them. Project Arqueros, located at the mid northern part of Chile, is a copper mine project with an orebody consisting of various sulfides such as chalcopyrite, chalcocite, and bornite. Some of the copper minerals in Arqueros show low floatability mainly because of their fine grain size and resulted fine grinding size, and also because of the complex mineralogical composition. For example, chalcopyrite in Arqueros floats less than the other copper sulfide minerals. In this study we carried out some kinetic flotation tests with the Arqueros ore using a laboratory-scale forced air type flotation machine by varying the regrinding size. The products were assayed and mineralogically analysed to compare the minerals in their flotation behaviour with respect to size classes and liberation classes. The results were compared with a model calculation according to bubble size measurement. From the flotation testing and mineralogical analysis, it was found that copper minerals of the same size and liberation class floated at the same rate even with different regrinding size. At the same time the comparison between experiment and calculation showed that the fine particles of less than 5 µm size floated faster in actual than in the model applied. These results suggested that interactions among minerals of different species and of different sizes had positive impacts on the flotation rate of the fine particles. It indicates that this phenomenon can be applied to improve copper recovery in the project.

Aug 24, 2022

The last one decade in India had witnessed phenomenal growth in the coal, lignite, iron ore, limestone and many other minerals. To meet the production of minerals, the energy requirement is also very high both in terms of petroleum products and electrical energy. Because of spiralling prices of crude oil and also of the electrical energy, attempts have been made by various mining companies to select energy efficient mining machineries (in underground and surface) mines, together with energy efficient mining and mineral processing operations. Mineral sector of India is working seriously in tune with the Planning Commission stipulations to conserve energy.Apart from energy use (both electrical and fossil fuels) in mining, it is also significantly contributing to the cost of mineral processing depending on the quality of ore/rock being processed. Over the years a number of studies have been initiated and implemented to reduce cost of energy bill. An attempt has been made to present the various aspects of energy conservation, Impact of Energy Conservation Act 2001, Relevance of energy audit, areas of energy consumption and conservation efforts, etc in this paper. The paper also deals with some of the case studies to show how energy conservation programs has been implemented in the Indian mineral sector.

Dec 6, 2010

By S Logan, J Pu, J Milsom, G McDonald

Management of environmental issues is an integral part of the mine decommissioning process. In Queensland, miners must comply with environmental aspects of the Mineral Resources Act and Contaminated Land legislation. Successful decommissioning involves the integration of a final Plan of Operations, decommissioning report addressing the mineÆs commitments included in its Environmental Management Overview Strategy (EMOS), and Site Contamination Report for relinquishment of leases under the Contaminated Land Act (1991). Niugini MiningÆs Red Dome Mine is proceeding through the decommissioning process. This paper discusses the important environmental management issues including sampling programs, management of culturally significant areas, assessment of background concentrations of target analytes, the use of historical reviews and risk assessment techniques, the timing of works, and the remediation/management of large areas of impacted land. The importance of a clear communications plan between key stakeholders is also discussed.

Jan 1, 1998

The usual metallurgical, engineering and administrative activities associated with the handling and smelting of ores, and the subsequent handling and treatment of the products of smelting, present also problems of hygiene that engage the earnest attention of executives in all well-managed concerns.Again, associated with the employment of any considerable number of men, there is always present the problem of accident prevention.INDUSTRIAL HYGIENE.In the earliest records of lead min.ing and smelting there are references to the injurious effects of lead oh the health of the employees, and, with the advancement of medical science, lead poisoning has been the subject of many works by various authorities in many countries.Moreover, in practically every civilised country, there are laws governing the conduct of the lead industry, and in most cases these laws stipulate that employees shall receive compensation for disability caused by lead poisoning.This provision gives the problem an economic aspect. Apart from the legal and the economic aspects, however, there is the humanitarian aspect, which implies that the...

Jan 1, 1937

By R H. Eric

Surface wave formation induced by a high-strength submerged jet in a bottom blown metallurgical vessels has been studied experimentally by using one-seventh water model of CLU (Creusot-Loire Uddeholm) reactor with two different tuyere configurations. Experimental results have been discussed in terms of the wave period, wave frequency and wave amplitude with respect to air injection rate and tuyere configuration at a 0.23 m bath height. The results from high speed photography observations displayed the formation of rotating surface waves which circulates within the water model. It was found that the frequency and the amplitude increased with gas injection rate. The wave period for off-centre nozzle orientation was found to be lower than those of the centre configuration. The experimental results also showed that the frequency of a rotating wave increases when the tuyere orientation becomes off-centred . The predicted amplitudes were in very good agreement with the experimental values over a range of gas flowrates between 0.00599m 3/s to 0.01081 m 3/s.

Jan 1, 2000

IN presenting a'description of milling and treatment methods at the Waihi mine, it is advisable to first traverse a good deal of the past history of the mine, and show the various steps which have led up to present-day practice. The record of the company is one of steady, solid advancement, both in metallurgical and financial results. This is illustrated by the following figures, dating back from 1897...

Jan 1, 1912

By E J. Y Koh, G J. McLachlan, E Amini, N Beaton

Preconcentration greatly reduces the ore mass input to the processing plant while upgrading the grade. One of the commonly used methods of preconcentration is optical sorting. These methods rely on optical sensors which classify the material stream into “accept-reject” streams. Currently, it is common to use near infrared (NIR) or colour cameras to classify streams based on reflectance or colour thresholds set by experts. The imaging is done through line-scan sensors where the material is scanned on a belt or a chute. Then, a separation apparatus like a diverter gate or air jet is controlled to separate the streams according to the classification made by the algorithm. Separation efficiency is dependent on the classification algorithm. Existing classification algorithms rely on low-level feature discrimination like observing individual pixel values for reflectance or colour hues. This limits discrimination between minerals with low contrast in colour. Human experts perform mineral segmentation using texture, colour distribution and shape, but it is difficult to translate these visual rules to mathematical thresholds. Deep learning methods like Convolutional Neural Networks (CNNs) provide high-level feature discrimination similar to a human expert. Instead of relying on pre-defined features, the CNNs learn complex features from the dataset. CNNs can construct a hierarchy of features based on pixel clusters to learn texture, shapes, and colour spectrums of the mineral grain surface to provide better separation. In this study, a state-of-the-art deep learning instance segmentation method is used to outline boundaries and classify grains from the background (mineral segmentation). The algorithm is trained on images collected from a flotation feed of a gold deposit, where the gold is mechanically locked inside pyrite. This method can process on-line video inputs at 5 frames per second to provide a live grade. The proposed method is inexpensive as it only uses a camera and a desktop computer.

Nov 10, 2020

The purpose of this paper is to outline some aspects of the experimental worlr that has been carried out in the mineral dressing laboratory at M'ount. Morgan during recent years.The subject matter has been dealt with under the following headings:1. Comminution of various mill products.2. The application of sulphur dioxide as a flotation reagent.3. Heavy-media separation.4. Bulk flotation of sulphide ores.COMMINUTION OF VARIOUS MILL PRODUCTSThe following data were cbtained by processing fractions of reserve grade ore.Granular TailingIn Table 1 are shown the results of tests on material representative of average grade tailing. In the first test (H1 ) the granular tailing was floated as received and in the second test (Ha) the tailing was ground prior to flotation.

Jan 1, 1952

By Ueki S

Underground coal gasification (UCG) is a promising process for obtai- ning energy from coal, which is either unmineable with current mining techno- logy or uneconomic to recover, using conventional methods, in the present energy market situation. There are several coal fields, which could become new coal reserves, if the UCG process were successfully applied. In the 1960's Japanese researchers made a number of basic studies and field tests into UCG, although not all of them produced favourable results. This paper reviews Japanese research on UCG. This includs basic studies into coal gasification using a small, tube reactor fed by air and oxygen, and also large scale model stu- dies(reactor size of 8.Om x 2.4m x 1.5 m). Field test results from Akabira colliery in Hokkaido and a feasibility study of power generation using UCG from a coal field in Hokkaido are also Presented.

Jan 1, 1987

The method of investigation was to study the distribution of ore in great detail, to make a thorough structural study of the lode and the mine area, and then to compare the results of the two studies. Such a comparison usually reveals a very close relationship between geological structure and ore distribution, and can often lead to important conclusions which would not be reached in the ordinary working of a mine.The Triton mine lies 30 miles E.N.E. of Cue, or 380 miles N.W. of Kalgoorlie, in typical pre-Cambrian rocks, consisting of gTeenstone lavas and tuft's, interbedded with slates and some sediments, and intruded by granite and porphyry. Fig. 1 (at end of paper) is a longitudinal section of the mine and shows that the workings consist of the main North Emu and the smaller South Emu, separated by a distance of about 1 of a mile. Both orebodies occur on the same lode, which strikes north and south and dips practically vertically. On the same line, and of 1/2 a mile and a mile respectively to the north of the North Emu, are the small Rand and North Rand workings, where a big width of lode material has proved to be very low grade. In the North Emu the lode width averages 12 to 15 feet; it is seldom less than 5 feet and in places reaches 30 feet. In the South Emu the lode is wide, but only portion of it is payable.The lode is a mineralised bed occurring between massive lava flows on the east and a mixed series of tuft's and thin lava flows on the west. The lode material is hard, fine grained, and dark coloured, and generally has a faint banding which is believed to indicate a tuft'aceous origin of the original lode rock. Microscopic examination shows that the original lode rock has undergone considerable albitisation;' there has also been considerable formation of biotite which gives the lode material a characteristic sheen. The mineralisation consists of abundant fine pyrite, which is auriferous, and a lesser development of pyrrhotite which is, however, barren of gold.THE OREBODIES AND THEIR CHARACTERISTICSThe distribution of ore is best studied from gold contours, as these reveal features that cannot be detected in an ordinary assay section. Gold contours (see Fig. 3) are developed' by plotting the width and grade of all development and stoping assays throughout the mine on a longitudinal projection, representing each sample by a coloured dot according to a suitably chosen range of assay values, and then outlining areas of similarly coloured dots (see H. J. C. Conolly, Econ. Geol., April, 1936). Both width and grade must be taken into account and the simplest method of gold contouring is to use dwt.lft. values, but difficulties arise here with big widths of low grade and small widths of high grade ore. To choose an extreme case, 30 ft. of 2 dwts. and 2 ft. of 30 dwts. both equal 60 dwts.lft., and would therefore be given the same value in dwt.lft. contouring...

Jan 1, 1943

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

By R A. Pax

Operational grinding mills emit significant acoustic emissions which are a consequence of the dynamic environment prevailing inside them. From a technical perspective, the noise presents an opportunity to determine some details of the processes occurring inside the mills. The noise generated is not random and can be attributed to a range of events that occur inside these mills, consequently non-contact acoustic determinations of in-mill behaviour provide powerful insights into the operation of primary comminution tumbling mills. To enable a logically coherent picture to be formed of the processes inside a mill, arrays of microphones have been used. This approach allows a clearer picture of the in-mill behaviour of the charge to be accessed. In contrast to single microphone approaches, usually located near the expected charge toe position, an array of microphones allows much more useful information to be obtained from grinding mill noise.This paper will discuss and present data obtained from microphone arrays positioned at the toe and shoulder locations of a mill, and how this information can then be used for the optimisation of grinding mills in real-time.CITATION:Pax, R A, 2012. Determining mill operational efficiencies using non-contact acoustic emissions from microphone arrays, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 119-126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

Evaluation of the Iron Blast Furnace Process using Heat and Material Balances of the Flame-Zone

Sep 13, 2010

The ore is very 'refractory. It consists essentially of arsenical pyrites, iron pyrites, zinc blende, galena, antimony as sulphide and probably, in combination with galena, as Jamesonite, magnesium, and aluminium silicates with quartz. Some of the oxidized ore, of which there is very little, has a very interesting composition. A specimen shown to me by the ,general.manager, Mr. F. B. Stephens, consisted of hydrated arseniate of iron, orpiment, pyromorphite, lead oxide, with magnesium silicates and quartz. The ore found in the mine with a composition similar to this specimen was valued for gold contents at 60 oz. per ton. This ore is found as a small leader, which runs parallel to the main ore body, at intervals cutting through it.The ore is conveyed from the mine to the reduction works by means of a double road tram line. The mine is situated about rooo feet above the plant on a hill. The grade is so great (about I in 2) that the loaded trucks coming down are able to pullthe empty ones up, thus obviating the necessity of motive power for haulage. All that is necessary is two large grooved pulleys, fixed at the summit of the hilI, and provided with a rope-break for steadying the speed of the trucks down the hilI.

Jan 1, 1903

The geographical region of South East Asia is variously defined, but generally agreed to include the Asean group - Philippines, Malaysia, Thailand, Singapore and Indonesia. Other regional countries, such as Vietnam, Laos, Burma, Kampuchea etc. are of course geographically part of the region, however in economic terms, they play a minor role. It is the Asean group that dominates present economic activity and provides the overwhelming opportunity for commercial development. My experience in South East Asia has been gleaned over 15 years of regular travel in the region. More recently, we have established company offices in Malaysia, Singapore and Indonesia to extend and deepen contacts with major customers. This progressive development is an integral part of a planned growth pattern and will be discussed in more detail shortly. South East Asia is a rapidly developing economic growth centre, a fact which is clearly recognised and accepted by most commentators. An important question is then to be asked: Why has the region been relatively neglected by Australian, U.S. and European industrial supply companies? I will attempt to address this question in the context of industrial minerals and propose some ideas as to how effective sales programs could be developed. Firstly, let's consider the market potential provided by countries within the region. It is reasonable to suggest that industrial growth in S.E. Asia over the past 20 years has been generally steady and in some cases, explosive. Until recently, this growth has predominantly been driven by development of internal (regional) demand. Population growth and rising living standards have ensured that basic industries have enjoyed a solid uptrend in sales and production. The industries which most benefitted from regional economic development over this period were, interestingly, those which we understand to be major users of industrial minerals - glass, ceramics, paper, surface coatings, cement, refractories, rubber and plastics. Each of these industrial sectors has been influenced by different growth stimulii over a 20 year period. Nevertheless, they also enjoy a common feature which ensured an above average performance. All sectors are fundamental to an environment enjoying rising living standards and rapid growth in general prosperity. More recently, internal growth factors have been overtaken by a recognition that manufactured products from the region are competitive in export markets. This comparatively recent development provides the most interesting possibilities for higher value industrial mineral raw materials. Let me explain: For 20 years, industrial growth in South Asia has essentially been focused on satisfying domestic demand. Finished quality of manufactured items was orientated to a developing market more interested in cost than aesthetics or long life. This was reflected in raw material specifications, which often did not exist and at the best were undemanding.

Jan 1, 1989

By Ross R

Although mining is an old industry its management is quite a new science, and its complications are now being recognised as demanding expert knowledge in many branches of technical and professional education. Not the least amongst these isaccountancy, for probably its most important problem is "How to control the expenditure." Unlike most businesses a mining company stands almost entirely in the light of a purchaser in the world's markets, and not as a seller, except say for product so the established and perfected systems of modern industries cannot be adopted for mining purposes. For this reason it has been left for late years to consider the matter seriously, and now a number of well-managed concerns have devised costs systems to suit their own requirements.Very little, however, has been published and even that is disjoined and difficult to make use of. Some of the costs systems in vogue, although elaborate and imposing, are not of very great value for keeping check on wasteful expenditure, or for displaying the commercial effect brought about 'by any particular change in practice, or by an addition or alteration to a portion of existing plant.

Jan 1, 1912

By M Boyd

The University of Wollongong was named University of the Year 2000, for its work in preparing students for the e-world. Computer facilitated learning is being introduced into subjects throughout the engineering course. First year mining engineering students are introduced to computers, e-communication, using the UniversityÆs web based information system, and web based subject delivery. Mining engineering students in the mid-years of the course use programming languages and numerical computation software such as MATLAB, while students in the final years use a range of commercially available professional engineering software such as TALPAC. Most of these subjects are offered as part of the UniversityÆs Learning Online program, co-ordinated by its Centre for Educational Development and Interactive Resources (CEDIR). Learning Online subjects are delivered using the Web Course Tools (WebCT) environment. WebCT allows all resources to be accessed through the web, allows email communication between lecturer and student, and allows discussion groups for the exchange of ideas. Students can submit their assignments through WebCT and receive immediate feedback. This paper describes how WebCT has been used to deliver a first year engineering computing subject, mid-year numerical computation subjects, a mining economics subject and mine planning subjects.

Jan 1, 2002

By M Chen, G H. Wang, J R. Zhou, P Yan, W B. Lu

Blast vibration analysis is one of the important topics in the control technology of blast vibration damage. Nowadays, blasting vibration safety standards are based on both the particle velocity and the frequency of vibration and they have been adopted widely and internationally. However, the analysis on vibration frequencies is less studied compared to investigations of peak particle velocity. For the vibration induced by a spherical charge in a viscoelasticly infinite rock mass, an expression of vibration spectrum taking into account the damping effect of rock mass is inferred. Then the attenuation laws of dominant frequencies and centroid frequencies are compared theoretically. For the case of cylindrical charge, dynamic finite element method (DFEM) software of LS-DYNA is employed to analyse the attenuation laws of characteristic frequencies. The research demonstrates that, no matter whether it is a spherical charge or a cylindrical charge, there is a local mutation or fluctuation at some distance when the blast proceeds, while the centroid frequencies conform to a smooth attenuation law. Both the multipeaks structures of vibration spectra and the decay rate difference between high- and low-frequency components contribute to the mutation or fluctuation investigated in this study. Additionally, an increase in longitudinally sonic velocity or the quality factor of rock mass produces an increase in the vibration frequencies, whereas an increase in blast source diameter or the rise time of blast load produces a decrease in vibration frequencies from a spherical charge. In borehole blasting, there is a positive correlation between the vibration frequencies and charge diameter, whereas there is a negative correlation with charge length. And altering the initiation plan will change vibration frequencies to various degrees. Finally, theoretical analysis results were validated by the empirical data from field experiments of Fengning pumped storage power station.CITATION:Zhou, J R, Lu, W B, Chen, M, Yan, P and Wang, G H, 2015. A further study on the attenuation laws of blasting vibration frequency, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 673–682 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By S Udayakumar, S Biswal, N Sarmadi, V Sahajwalla, F Pahlevani

Recent times have witnessed a notable momentum in the interest surrounding technology dedicated to harnessing waste as valuable resources, prompted by the mounting challenges posed by waste accumulation and the swift depletion of natural resources. The carbon dissolution process within a molten iron bath stands as a pivotal reaction within the metal processing sector. The current study explores the utilisation of waste graphite electrodes (WGE) (obtained after being utilised in an electric arc furnace) as a secondary resource of carbon for dissolution into liquid iron. Experimental investigations were carried out at 1550°C using the sessile drop approach. High purity iron powder was used and the carbonaceous substrates were prepared from the ground WGE. The carbon pickup was determined using a suitable carbon analyser. Furthermore, an examination of the interfacial area between the molten iron and the WGE substrate was conducted beneath the metallic droplet, which effectively represents the iron/carbon interface. This interfacial analysis was carried out on two different samples obtained after a varying period of heat treatments at 1550°C. The interface layer was investigated using scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray spectroscopy (EDS).

Jun 19, 2024