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By V. Alexandrov

This paper presents the results of theoretical investigations of the energy requirements of the hydraulic lifting of mined materials from the seabed to the sea surface in the deep-sea mining of solid minerals such as manganese nodules in the Clarion-Clipperton region of the Pacific, situated on the sea floor in water depths of 4,500 m or more. The principal element of the developed underwater transport system is the Underwater Chamber, which is connected by flexible pipeline to a mining machine that gathers nodules from the seabed, mixes them with seawater, and feeds them into a flexible pipeline. In this paper, we discuss the question of the optimum water depth for placement of the Chamber, the interior of which is designed to maintain a 1-atmosphere pressure. We present a method for calculating this depth as it relates to the mechanical characteristics of solid particles, the shapes and size distributions of the particles, particle and slurry density, and other properties. These investigations were carried out in hydro-transport laboratory of the Saint-Petersburg Mining Institute and the hydraulic laboratory of Faculty Environmental Engineering in Wroclaw Agricultural University. KEY WORDS: deposit, nodule, flexible pipeline, pressure drop, concentration, hydromixture

Jan 1, 2005

By W. M. Houston

The phosphate formations of the Pliocene epoch were deposited along the coastal shelf of the eastern seaboard. The deposition of the phosphate is thought to be somewhat contiguous along the early shoreline, and the deposit can be more or less traced over an 800 to 930 mile path from the Florida Gulf Coast, near Ft. Myers, to the Pamlico Sound of North Carolina. This is illustrated in Figure 1. Three areas of commercial importance are currently being exploited from this extensive known deposit: 1 - The so-called ?Bone valley? in Central Florida (multiple operations) 2 - Hamilton County in North Florida (Occidental Corporation operation) 3 - Beaufort County in North Carolina (Texas Gulf Sulphur operation)

Jan 1, 1966

By D. Chadwick, J. W. Matousek

Between 1860 and 1890 -- from the time of the American Civil War to the last decade of the 19th Century -- nickel production in North America was dominated (even monopolized) by the output of the industrial complex of the Gap Nickel Mine near Lancaster, Pennsylvania and the American Nickel Works in Camden, New Jersey. In some years, from one sixth to one third of the world's metallic nickel supply came from this enterprise. Mining and smelting were conducted at Lancaster; a matte of high iron content was shipped to Camden for pyrometallurgical and hydrometallurgical refining to produce nickel metal, copper sulfate, and cobalt oxide. The high purity nickel product was rolled into sheet for marketing, primarily for coinage, as nickel had few other uses at that time. The undertaking experienced all of the problems that face the mining and metallurgical industries of today: declining reserves, high labor and fuel costs, high transportation costs, fluctuating demand and prices, pollution concerns, and foreign competition. The technical features of the geology; the mining, smelting, and refining operations; and some of the economic aspects are assessed. The view is taken from that of the present time -- seeking those lessons from history that we are supposed to learn or face the prospect of repeating the mistakes of the past.

Jan 1, 2005

By P. Barnes

Several statements have been made to the Institute, somewhat detached from each other, as to the cost of some parts of these works, but they have not included any extended description of the buildings or machinery. The general plan of the work connected with the water supply differs, in some important details, from that which has been common either in the Pittsburgh district or elsewhere, and a somewhat extended description may be of interest to the Institute, in connection with a note of the cost of the work. The plan as a whole, and nearly all the important details, were developed by Mr. William P. Shinn, C.E., the general manager of the Company. The immediate and responsible charge of the work was in the hands of Mr. John C. Lewis, C.E., to whom had been committed all the work of this general description, including the laying out of the whole of the foundations, the erection of the buildings, and the grading and laying down of the entire railroad system. The continuous operation of the machinery and other fixtures of these waterworks, for more than three years, has fully demonstrated the correctness and econonly of the plan adopted. No casualties of any moment have befallen the apparatus, and no improvements have been suggested as important except that the gate at the river end of the conduit should have been made more completely water-tight, so that the whole length of the conduit could be pumped out dry without resort to any temporary dam in the conduit itself. In general terms the works of the Edgar Thomson Company are situated on a plateau, about 52 feet above the low-water level of the Monongahela River, and about 2000 feet from its bank. The site of the works is bordered on one side by Turtle Creek, a small stream which drains a considerable area of coal mining territory. This creek is about 100 feet from the group of buildings which have been erected, but it flows into the Monongahela River at a point, about 1200 feet further up than that selected for the entrance to the waterworks conduit. It was ascertained by analysis that the water in the creek contains an important percentage of sulphate of lime, while the water of the river is of unusual purity, in respect of any salts

Jan 1, 1879

By T. Skinner, M. Sahebkar

"In recent years, the mining industry has been inundated with new technologies and software systems to aid in productivity improvement. Accompanying this increased level of technology and computer systems has been the exponential growth in data sources and sinks for all aspects of a mining operation. This rapid growth in data and technology has evolved through vendor “push” approaches and user “pull” scenarios, the result of which has been that currently, no standards exist defining how data from new technology should be accessed and transferred from surface mining equipment and systems. Consequently, many incremental benefits of the systems have not been realized. This paper will present a discussion of this important issue and introduce a new committee formed to address standards to assist the industry in making effective use of current and future technology. Potential benefits accruing from the development of these standards will be illustrated through the use of a case study at Fording Coal Limited. IntroductionThe mining industry is currently faced with a rapid evolution in the computing-based systems capabilities of mobile production equipment. At the same time, there is a trend toward the introduction of even larger machines, with novel designs or incorporation of new technologies within existing designs. Computing and control technology will be required to operate and acquire knowledge about equipment operation, utilization, and performance. Such knowledge has the potential to lead to enhanced equipment design, more appropriate equipment selection, and optimized equipment performance. The equipment systems will be required to be integrated with mine production monitoring systems, maintenance management software, and a wealth of other information systems to provide a complete understanding of the effects of various factors such as maintenance, equipment design and production on economics (Roman and Daneshmend, 2001). This will lead to a better understanding and implementation of the opportunities to enhance the performance of the mine through interaction of the mine operations."

Jan 1, 2003

By A. V. Bradshaw, R. I. L. Guthrie

The behavior of large bubbles in the size range 4 to 25 cm3, rising through molten silver, has been studied. It was found that rising velocities were equivalent to those in aqueous systems of low viscosity. Mass transfer coefficients for oxygen bubbles dissolving in silver were found to be 0.036 ± 0.007 cm sec-1, being close to those predicted for transfer through the front surface of the spherical cap bubble only. It is suggested that the surface active nature of oxygen in silver could account for the relatively low coefficients obtained. MANY metallurgical processes involve interactions between gas bubbles and liquids. Examples include the removal of carbon monoxide in Open Hearth Steelmak-ing, the removal of sulfur by blowing air through copper matte during converting, and the removal of hydrogen from steel during vacuum degassing or inert gas flushing. The steps involved in such refining processes include; transport of the dissolved species to the bubble interface, adsorption and chemical reaction of the species at the interface, desorption of product molecules from the interface, and transport of product gas into the bulk gas phase of the bubble. It has been concluded1 that all the interfacial steps involved proceed so rapidly at steelmaking temperatures that transport of the solutes, present in the metal, become the important rate controlling factors provided nucleation phenomena are not restrictive. The O-Ag system was chosen for the investigation into gas bubble-molten metal interactions due to the relatively high solubility of oxygen that enables rates of oxygen transfer to be measured from changes in bubble volume. Other advantages of this system include the absence of a stable oxide phase at an oxygen pressure of 1 atm and the relatively low melting point of the metal which permits the use of a metallic container, providing that it is resistant to oxidation. In those metallurgical processes where bubbles have an important influence, bubble volumes are usually greater than 5 cm3. For this reason the present study relates specifically to single large bubbles of oxygen rising in silver. These bubbles adopt the characteristic spherical cap shape similar to that shown in Fig. 1 for a 30 cc bubble rising in water. After an initial investigation to determine the velocities of inert (nitrogen) bubbles rising in molten silver, experiments were carried out with oxygen and the rates of mass transfer between the oxygen bubbles and the silver were measured. EXPERIMENTAL Apparatus. The apparatus, Fig. 2, for containing molten silver, was constructed from "Nimonic 75" Alloy (75 pet Ni, 20 pet Cr, 5 pet Fe, Mn) and provided for the release of single bubbles from an hemispherical cup, situated at the bottom of the column. The cup was turned by translating the rotation of the drive shaft through 90 deg. This was accomplished by the use of a bevelled gear system, and a smooth drive was provided by the lubricating action of the silver on the gears. Since reliable high temperature seals at 1000°C were found to be impracticable, the filling and drive shaft tubes were extended outside the 3.5 kw resistance wire tube furnace, where connections were made using easily accessible O-ring seals. The apparatus remained gas tight to the atmosphere at pressure differentials far in excess of those used. The filling tube was connected via a small bore tube to the differential pressure transducer. Gas could be bubbled into the inverted cup from two i-in. tubes which passed down the inside of the column to preheat the gas. The temperature of the silver was maintained at 1020°C during all experiments. Measurement of Bubble Volume. In order to calculate mass transfer rates, it was necessary to obtain a continuous record of the bubble's volume during its passage through the column of molten silver. The method adopted for measuring the bubble volume involved closing off the top gas space to the atmosphere prior to each experiment, and recording the variation in gage pressure of this space during the formation and rise of the bubble. Since any change in bubble volume results in an equal change in top space volume, Boyles Gas Law may be applied (for isothermal con-

Jan 1, 1970

By James R. Cudworth, Joseph C. Mead

The Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manufacturing puzzolan cement; two companies, Birmingham Slag Co. and Woodstock Slag Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. NO Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive. Sources of Slag In the Birmingham district there are 22 blast furnaces, of which the majority are in blast. The present production is 165,000 tons of pig iron monthly; the production in 1935 was 1,297,960 gross tons1. There arc also two blast furnaces at Gadsden and one ferroalloy electric furnaee at Anniston. From these two sources is obtained slag to approximately 1.1 tons per ton of pig iron. History of Development of the Industry The history of the local utilization of slag as an industry probably starts with the Birmingharii Slag Cement Co. This company was

Jan 1, 1938

By Joseph C. Mead, James R. Cudworth

The Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manufacturing puzzolan cement; two companies, Birmingham Slag Co. and Woodstock Slag Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. NO Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive. Sources of Slag In the Birmingham district there are 22 blast furnaces, of which the majority are in blast. The present production is 165,000 tons of pig iron monthly; the production in 1935 was 1,297,960 gross tons1. There arc also two blast furnaces at Gadsden and one ferroalloy electric furnaee at Anniston. From these two sources is obtained slag to approximately 1.1 tons per ton of pig iron. History of Development of the Industry The history of the local utilization of slag as an industry probably starts with the Birmingharii Slag Cement Co. This company was

Jan 1, 1938

By J Pan, Q H. Li, D Q. Zhu, C C. Yang, X Wang, Z Q. Guo

Al2O3 in natural iron ores generally occurs in goethite, kaolinite, gibbsite, hematite and iron carbonate. When the content of alumina in sinter increases from 1.11 per cent to 3.50 per cent, the reducibility of sinter decreases with the addition of four different types of alumina. When gibbsite and kaolinite are added, the low temperature reduction disintegration (RDI+3.15 mm) of sinter increases with the increase of Al2O3 content in the range of 1.5 per cent to 3.5 per cent. Furthermore, when adding pure reagent alumina, the increase of Al2O3 content in the range of 1.5 per cent to 3.0 per cent will increase the RDI+3.15 mm of sinter. The addition of ferric oxide–alumina spinel with the Al2O3 content in the range of 1.5 per cent to 2.5 per cent, also increases the RDI+ 3.15 mm of sinter. The influence difference is results from the change of the mineral composition and microstructure of sinter because of the occurrence state of Al2O3. Under the condition that Al2O3 content of sinter is 2 per cent, the porosity of sinter with kaolinite is 37.26 per cent, and the shape is irregular. When gibbsite and ferric oxide–alumina spinel are added, the porosity of sinter is about 16 per cent, and the pores are round. When pure reagent alumina is added, the porosity of sinter is 17.49 per cent, and the pores are regular and small. When kaolinite, gibbsite and ferric oxide–alumina spinel are added, platy calcium ferrite is mainly formed in the sinter, and some of it is columnar calcium ferrite. On the other hand, when pure reagent alumina is added, in addition to platy columnar calcium ferrite, acicular calcium ferrite is also formed in the sinter.

Nov 8, 2021

By S. Q. Yang

Rotary radial jet improves greatly the pulsing velocity of airflow along each direction everywhere in the entry, intensifies transverse migration of air, eliminates effectively the local gas accumulation, and distributes methane concentration in airflow evenly and rapidly. According to the theoretical analysis of heat-transmission, mass-transmission and momentum-transmission, not only the similarity between heat-transmission and momentum-transmission, but also the similarity between mass-transmission and momentum-transmission exists in turbulent flow field, When the analogical equivalent ratio of heat transmission and mass transmission meets a certain criterion and remains a certain value, the temperature field can be used to simulate the methane concentration field. After hot airflow being released, thermograph instrument can be used to monitor the changing patterns of heat transmission and temperature distribution which simulates the changing patterns of methane transmission and methane distribution respectively. By analyzing these patterns and parameters of airflow field and methane distribution field during the process of local gas accumulation discharging by rotary radial jet, the dependability and validity of this discharging method are tested and verified.

Jan 1, 2004

By E. S. Moore

Introduction The geology of the Sudbury nickel field has been studied extensively, but there are few reports dealing with the structure of the interior of the basin. It was not until the Treadwell-Yukon zinc-lead deposits were discovered that attention was strongly directed toward the large-scale faulting that has split the basin parallel to its long axis. This faulting has been responsible for the , ore deposits in the basin and it may be regarded in many ways as the most important geological event, next to the intrusion and differentiation of the nickel eruptive sheet, that has occurred in the Sudbury region. The early reports on the nickel region by Bell, and Barlow, were chiefly concerned with the nickel-copper ores and with the formations of the region. Coleman was the first geologist to map the nickel eruptive as a continuous sheet around the belt and to emphasize its basin character. On the map accompanying his later report, he shows an important offset in the nickel eruptive at its southwest end, where the large fault cuts this portion of the basin, but the fault was not traced into its interior, as little detailed work was clone in the basin at that time. No ore-bodies had been developed outside of the nickel-copper deposits associated with the norite when the map was prepared, and attention was mostly concentrated on the nickel eruptive. Coleman did, however, map and name the various formations found within the basin and, in general, his delineation of these has remained the standard for prospectors and other workers in the field until the present day.

Jan 1, 1930

Feasibility studies in the development of mining projects are fundamental to most investment decisions. It is important that the issues addressed and the degree of detail involved in feasibility studies are consistent with the investment decisions to be taken. Emphasis should be placed on a thorough analysis of critical project parameters prior to detailed investigations being undertaken into other activities which are not relevant to the decisions at hand. Therefore, the issues to be decided upon should be influenced significantly by the stage of development of the project and by the reliability of technical and financial information used in the study. Some of the more critical parameters of feasibility studies are commodity prices, inflation rates and discount rates. Advice is given on the selection of these inputs and also on their application in the feasibility study as the project progresses through its various development stages. The feasibility study should involve not only a formal evaluation of project economics but also an analysis of all project related risks and a comparative analysis of projects competing in

Jan 1, 1983

By R. Flores V.

The Refugio Project is located in the Andes mountains of northern Chile, in the Maricunga Hineral Belt. The Verde, Pancho and Guanaco Au ore bodies have been recognized and are Early Miocene in age. Mineralization consists of fine-grained disseminated gold hosted by dacitic to dioritic subvolcanic porphyries. Alteration comprises massive to veinlet-controlled silicification overprinted on earlier potassic and propylitic alteration and surrounded by later argillic alteration. Geologic relationships suggest that the Refugio ore bodies occur within an Early Tertiary volcano overlying Paleozoic and Mesozoic basement rocks. Geologic reserves at Refugio are approximately 300 million grams (9.7 million ounces) of gold. The Verde deposit contains 185 million tonnes of mineable and leachable ore with an average grade of 0.90 glt Au and is currently in the pre-construction stage after a positive feasibility study. Proven and probable mining reserves at Verde deposit are 101 million tonnes at an average grade of 1.02 glt gold. Additional potential exists at to other deposits within the Refugio property (Pancho and Guanaco) but no reserves have yet been defined due to the limited drilling to date.

Jan 1, 1994

By H. Stanley Benson

This report is an account of research conducted to improve the performance of and then further field test Draft Power Sensor (DPS) equipment, the use of which enables a bulldozer operator to optimize his machine's work rate. Significant improvements were made in DPS hardware, and extended field testing was conducted at two working strip mines: the Glenharold Mine of Consolidation Coal Company, near Stanton, North Dakota, and the Beulah Mine of Knife River Coal Company, near Beulah, North Dakota. This report documents the increase of bulldozer work production by greater than twenty percent while using the Draft Power Sensor when compared to baseline work production without benefit of the Draft Power Sensor. Research was done by Southwest Research Institute under contract with the Bureau of Mines.

Jan 1, 1980

By Hans Jahncke G

El petróleo se forma por rocas porosas, que al producirse se llaman los "reservorios de petróleo". Por lo cual este debe poseer intersticios entre las partículas sólidas, que acumulen ciertos fluidos. Empero este no es el único fluido encontrado, sino que pueden contener aguas, gas, en tanto solución del petróleo libre. En este sentido, el objetivo del texto es señalar el funcionamiento del laboratorio de reservorio, en tanto determine estas propiedades, las cuales son básicas en todos los cálculos de reservorios, determinación de reservas, desarrollo de la producción y las posibilidades futuras de recuperación secundaria. Las funciones del Laboratorio de Reservorios de la International Petroleum Company se dividen en dos partes: El primero refiere el trabajo de campo, que incluye obtención de registros de presión, temperatura y determinación de niveles de fluido en los pozos y el segundo, los trabajos de laboratorio propiamente dichos como la determinación de las propiedades físicas de las rocas del reservorio y de los fluidos que contiene. Estos a su vez comprenden la saturación y permeabilidad. En cuanto a los trabajos de muestras de petróleo del subsuelo, encontramos factores como la presión de saturación, relacion de gas-petróleo, volumen de formación y viscocidad. Asimismo los análisis de trabajos de muestras de gas se realizan mediante el desplazamiento de fluídos por inyección de agua.

Jul 20, 1956

By Shenghui Guo, Ying Lei, Wei Li, Jinhui Peng, Libo Zhang, Yu Li

"In this work, the Panzhihua low grade ilmenite and graphite were milled for 1, 2, 4 and 8 h firstly, then the temperature rising behavior of milled sample in microwave field were studied. The average heating rate of samples milled for 1, 2, 4, 8 h were 1.86, 4.08, 2.82, and 2.32 K/s; Before optimize the microwave reduction process, several experiments were conducted in order to confirm the parameters range. After milled for 4 or 8 h and reduced above 930 oC, the Fe metallization are higher than 90%; Then the optimization was investigated by using response surface methodology (RSM), the significance of predict model and each terms were analyzed, and the optimization parameters were given as: milling time is 4 h; reduction temperature is 1001 or 1070oC; the holding time is 37.5 or 26.9 min. Under these conditions, the Fe metallization given by predict model is 91 or 92 %.IntroductionThere is about 9.66 billion tons of Vanadic Titan-magnetite deposits in Panzhihua, China. In this reserve, there is about 8.73×108 t of TiO2, accounting for 90.54% of the Chinese reserves, and 35.17% of the international reserves and ranking first in the world. [1] Titanium mineral deposits are classified into Rock type and Placer type. Rock type is the igneous mineral, which have high content of FeO (Relative to Fe2O3) and gangue. The Panzhihua ilmenite is a typical rock type ilmenite ore. The higher contents of MgO, CaO, SiO2 and the complex mineralogy are making its direct reduction progressively more difficult."

Jan 1, 2011

By R Peiffer, L van Wyk

The Port of Port Hedland is the largest bulk export terminal in the world and is one of Australia’s most important pieces of economic infrastructure. BHP is the largest Port user to support the export of iron ore products from mines located within the Pilbara region of Western Australia (WA). BHP’s priority is the safety and well-being of its workforce and the communities where it operates. In a recent regulatory application to increase export capacity, BHP committed to the deployment of wind fences to reduce wind erosion from stockpiled ore. Wind erosion from stockpiles was identified through inverse modelling as the most significant dust source compared to other sources such as stackers, reclaimers, shiploaders and transfer stations. The primary cause of dust emissions from stockpiles is dust lift-off during high wind conditions. BHP proposed the installation of wind fences across its Port Hedland operations, targeted at reducing emissions from wind dependent sources, primarily stockpiles, by reducing the wind speed downwind of the wind fence. Modelling predicts that installation of the wind fence will significantly reduce emissions from stockpiles, particularly at BHP’s western operations (Finucane Island). To be effective in shielding stockyards and reducing wind speeds, the wind fences are located upwind and as close as practical to the open stockyards. BHP’s wind fence design incorporates learnings from other existing installations and has been tailored for Port Hedland’s cyclonic conditions. The wind fence will be higher than the stockpile height, with a mesh porosity of approximately 50 per cent. The mesh porosity allows some of the wind to pass through the mesh. This reduces the wind turbulence downstream of the wind fence, as opposed to a solid wind fence, which increases downwind turbulence, resulting in increased dust.

Sep 18, 2023

By Scott G. Britton

Planning is a management tool used to solve problems and provide data and decision alternatives for company growth, profitability, and direction. Strategic planning is defined as the efforts needed to accurately measure the risks of obtaining a result from future actions given a finite number of outcomes. The techniques of strategic planning are being applied more and more to underground mine design as a result of the fierce market conditions underwhich the industry is facing today, and the conditions they will likely face in the future. The objectives of strategic planning are centered on the ability of the operator or company to manuever its limited resources to the best position available under the given future scenarios. This paper briefly examines the most popular techniques for accomplishing these objectives, how these techniques fit into the current mine management decision-making, and what results to expect from these techniques in planning efficient underground mines.

Jan 1, 1985

By Lawrence Addicks

AT the San Francisco meeting of the Institute last year, I presented, through the courtesy of Dr. James Douglas; some results of experiments on the roasting and leaching of concentrator tailings. After it became apparent that flotation rather than leaching was clearly the better method of handling the particular problem under consideration, before dismantling the experimental equipment, some data were secured on roasting and leaching the concentrate itself in competition with smelting. Some of the results obtained are given in the following paper and they a re of particular interest at this time in. view of the large quantities of flotation concentrates with their somewhat difficult smelting characteristics now being produced. A complete wet process? consists of roasting and leaching the calcines in dilute sulphuric acid produced from the roaster gases, roasting the residue with salt and leaching with dilute tower liquors (the well-known Longmaid-Henderson process) and recovering the copper, silver and gold by cementation or electrolysis or a combination of both. It is evident, however, that the residue from the first leaching, carrying about 20 per cent. of the copper and all of the silver and gold, can be smelted if preferable. In considering the application of the scheme to individual cases, it must be remembered that freight plays a. large part in any reduction process wherein smelting is not conducted at the, mouth of the mine, and that it is not practicable today to build small smelting plants for individual operations. The experiments may be grouped under four main heads: Roasting, leaching, chloridizing residue, and recovery of copper from solutions. The products of two concentrators were used: The Nacozari concentrates were the product of a large modern mill not using flotation, the copper mineral being largely chalcopyrite; and the Tyrone concentrates, the product of an experimental mill including flotation, the copper mineral being chiefly chalcocite. Typical analyses would be as follows:

Jan 9, 1916

By S Joyce, Z Agioutantis, D van Zyl, D Shields

Over the past 15 years, the mining industry has begun to incorporate the concepts of sustainable development and sustainable mining practice across the life cycle of mineral operations. This requires addressing economic issues, community impacts and concerns and environmental protection, and is captured in part by the phrase ‘design for sustainability’ (McClellan et al, 2009). Over the same period, the industry has seen a gradual decline in ore grades for many mineral commodities. As a result, large volumes of tailings and mine waste rock are being produced around the world, and it is expected that the annual production volumes of these materials will increase, even if there is not a significant change in the demand for materials.Another related thread of change has been the realisation that societies need to move away from linear economies (raw materials, production, consumption, disposal) towards more circular ones. This will help societies become more resource efficient, which is defined by the United Nations Environment Programme as reducing the total environmental impact of the production and consumption of goods and services, from raw material extraction to final use and disposal. The goal is to create more with less and deliver greater value with less input. Circular economies require thinking in terms of the waste hierarchy (reduce, reuse, repurpose, recycle, recover, landfill).The challenge is that the waste hierarchy was originally designed to address embodied mineral content in products rather than mine waste and tailings generation. It will need to be reconsidered in a mine life cycle context, focusing on a value-based conception of waste (Van Ewijk and Stegemann, in press).In parallel to these changes, it has remained an imperative in the mining industry to dispose of these waste materials as economically as possible while protecting the environment. Single handling of these materials has been the main target, which reduces the life cycle costs of their management but may make reuse of waste and tailings technically more difficult or economically infeasible.This presentation explores a rethinking of the large volume earthen material waste issue at mines. The underlying theme is that some or all of these materials can be valuable resources for the future that can positively contribute to sustainable development. These resources can offer economic gains to firms, communities and societies; contribute to environmental well-being; enhance social interactions with the previously mined landscape if handled properly; and, with proper policies in place, reduce governance commitments. Each of these topics will be briefly explored. This will be followed by a discussion of approaches to manage design and operations to allow future resource recovery.CITATION:Van Zyl, D, Shields, D, Agioutantis, Z and Joyce, S, 2015. Waste not, want not – rethinking the tailings and mine waste issue, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 7–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015