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By K Cochrane

Time and time again history shows us that mine closures are sustainability failures. Mine operators do not know how to turn the mine closure into an asset and communities around the mine do not know how to plan or what to implement to be sustainable when the mine needs to close. If we want to achieve sustainability when we close a mine, we generally need to consider what economic activity we will have to create leading up to the mine closure to ensure that the communities remaining in the area are not worse off after mining than before. There is not one silver bullet solution to mine closure, as all mines are affected by different environmental and socio-economic conditions. That is one of the reasons why mine closure is so difficult.Effective stakeholder engagement is the nucleus around which sustainability is built. Achieving sustainability as part of mine closure means not only a self-sufficient community, but also could lead to transformation of that asset.A key issue is that neighbouring communities become completely reliant on the mine. The mine has influenced the economic, environmental and social aspects of the community and with no alternative economic sources. The community and municipality will struggle with capacity to maintain infrastructure, services and jobs. This not only impacts the mine workers and their families but also other businesses and people in the town that make a living by servicing the needs of the workers and their families. Social problems associated with a mining operations and closures need to be considered. The misuse of alcohol, domestic violence, breakdown in law and order, economic and health issues all have a severe influence. Families often need to relocate from the mining town to find work. This further perpetuates the impact of the mine closure to the economic viability of the town. CITATION:Cochrane, K, 2018. Is your mine closure a sustainability failure? Transform your asset and create a self supporting neighbouring community. It’s as easy as ABCD!, in Proceedings Life-of-Mine 2018, pp 38–42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By J. Yianatos

The collection zone residence time distribution (RTD) of mechanical self-aerated flotation cells was characterized for liquid and solid per size class (-45 mm, +45-150 mm and +150 mm). It was found that a single large industrial cell with a volume of 130 to 250 m3, now used in plant operations, can be well represented by an LTST (large and small tank-in-series) model plus dead time. From a scale-up point of view, results showed a similar mixing behavior for industrial cells ranging from 130 to 250 m3. Also, single mechanical cells showed a similar mixing pattern (RTD) when compared to large pneumatic flotation columns. It was confirmed that for practical purposes, the mixing condition in a flotation bank of three or more cells in series can be well described by the classical N tanks-in-series model.

Jan 1, 2008

By Michael D. Balen

The Bureau of Mines (Bureau), in cooperation with the Alaska Division of Geological and Geophysical Surveys (ADGGS), conducted field investigations from 1987 through 1989 in the 5.7 million-acre Valdez Creek Mining District (VCMD) in south-central Alaska. The objective of the VCMD investigation was to evaluate the mineral resources and the mineral development potential of the mining district. The investigation was part of the Bureau's continuing statewide mining district evaluation program. Nineteen new mineral occurrences were identified as a result of this investigation. Reconnaissance placer sampling resulted in the identification of 10 previously unreported occurrences that primarily contain gold, however, some contain subsidiary platinum-group metals and/or tin. Reconnaissance lode sampling resulted in the identification of two gold-silver occurrences, three platinum-group metal occurrences that contain elevated quantities of subsidiary chromium, nickel and/or cobalt, three copper occurrences that contain subsidiary molybdenum or zinc, and one zinc occurrence.

Jan 1, 2011

By G. G. Eichholz

SUMMARY RADIOACTIVE dynamite has been prepared by introducing a small amount of antimony-124 into the explosive. Test work is described on the effectiveness of this tracer, on radiation levels in its neighbourhood, and on different methods of .application. Factors determining the choice of isotope, amount of activity, and overall cost of this process are discussed. INTRODUCTION Instances are known in which dynamite remains unexploded in drill holes in mining operations. Usually such 'bootlegs' are easily located by inspection of the face and the powder is removed before subsequent drilling is started. Occasionally, however, serious accidents occur because workmen drill into an undetected piece of dynamite. In order to avoid such accidents it was suggested that a different method of location might be tied, such as that afforded by the use of radioactive tracers. This paper describes some experiments that were carried out under the auspices of the Department of Mines and Technical Surveys, with the active co-operation of Canadian Industries Ltd. and Canadian Refractories Ltd., to test the feasibility of such a scheme.

Jan 1, 1957

By Tumilty JA, Schmidt CG

Sulphide ion is a powerful poison in gold cyanidation, however, the detrimental effect is less severe in plant practice. This is thought to be due to the presence of depassivating elements in the ore, mainly lead. Trace amounts of lead can counteract the poisonous effect of considerable amounts of sulphide. The reaction is instantaneous and is likely to be a direct involvement in the electrochemical surface reaction. Lead addition cannot be regarded as an all-round cure when experiencing poor leach efficiencies. A possible beneficial effect depends on the mineralogy of the ore and has to be determined individually for every material.

Jan 1, 1989

By F. G. Scott

This document is a proposed program plan for mining environmental research to be conducted by the U.S. Bureau of Mines in support of industrial oil shale mining and processing. This program plan is one of three research alternatives being considered by the Bureau, each based on a different level of anticipated funding. This report documents the mid funding level program plan.

Jan 1, 1980

By Thomas M. Barczak

This U.S. Bureau of Mines report chronicles the historical development of longwall mining in the United States and speculates on future developments to the turn of the century. The involvement and contributions made by the Bureau during these developments are also discussed. Two major periods of history are analyzed: (1) from 1875 to 1950 when small advancing faces were operated manually, and (2) from 1950 to 1990 when mechanized extraction and powered roof supports provided a system to efficiently extract large coal panels. Five eras of technological development during the modern period are described and analyzed. These eras discuss the development of (1) mechanized extraction, (2) powered roof supports, (3) high-capacity roof supports, (4) shield supports, and (5) system automation. Current trends are analyzed in terms of longwall utilization, face production, support capacity, face widths, and new technological developments. From these analyses, the future of longwall mining to the year 2000 is speculated. It is concluded that longwall mining will continue to grow in importance during the next decade and that the next major technological milestone will be the realization of a fully automated longwall mining system.

Jan 1, 1992

By C. J. Newman

Before 1995, the smelting process at the Kennecott Utah Copper Corp. (KUCC) smelter consisted of Noranda reactors and Pierce-Smith converters. When considering expansion, it was decided that the existing process would not lend itself to a program geared toward processing the total output of copper precipitate and copper concentrate from KUCC mining and concentrating operations. During 1989 and 1990, several smelting options were evaluated. The final selection was the Outokumpu flash smelting process, coupled with the new Kennecott-Outokumpu flash converting technology. Facilities were designed and installed to process 1 Mt/a (1.1 million stpy) of copper concentrate, with the ability to expand to 1.2 Mt/a (1.3 million stpy). The smelter facility that used the Noranda technology was shut down in May 1995. The flash smelting furnace operation began in June with the flash converting furnace start-up a few weeks later.

Jan 1, 1999

By R. Stefanko

In this report, the use of Penn State Ventilation Simulator (PSU/MVS) for planning and evaluating new coal mine ventilation systems is demonstrated. The simulator's application to evaluate the ventilation system of a coal mine currently under development is discussed. The ventilation system is evaluated for representing development of the mine at the end of 12, 24 and 36 months after mining has begun. The report describes the necessary steps of data input preparation, ventilation network development, analysis of results, modifications to the network, and methods to expand the computer program for networks larger than 550 branches.

Jan 1, 1977

By M. Drozd, M. Somppi, Z. Yamak

"Granular activated carbon is widely used in the gold mining industry for gold extraction from aurocyanide-containing slurry. The extraction process can employ carbon as part of the gold recovery operation for various circuit designs including carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) circuits. However, various qualities of activated carbon exist and the durability of the material can change significantly from source to source. Handling this expensive reagent can pose challenges when fine carbon losses occur in the CIP, CIC, and CIL circuits. Additionally, any gold that is adsorbed to these carbon fines can also be lost by various mechanisms including carbon attrition and fracturing, inefficient coarse-fine separation, and poor carbon fines capture. With the above in mind, a series of tests were conducted to investigate standardizing simple laboratory methods for testing carbon quality. A standard procedure beyond or enhancing ASTM methods can serve as additional starting points for evaluating carbon specific to the gold industry. The investigation focused on size distribution, flatness, wet attrition resistance, surface area, gold kinetics, and gold loading. The final results provided information to generate an equation for ranking carbon samples to plant performance.IntroductionActivated carbon for use in gold extraction is amongst the most commonly found processes in modern gold-milling plants. Although gold losses are inevitable in the milling process, operators often focus on the importance of maximizing gold recovery. One focus area that is important in gold recovery is optimizing the use of activated carbon and examining potential changes to realize improved economics for carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes."

Jan 1, 2017

By J. A. Yeats

This paper describes the loading to 25MN of a 1.2m diameter bored cast-in-situ test pile founded in the Thanet Sand which was base grouted. The pile was sleeved over the major portion of its length to test primarily the base response of the pile. The results are presented and compared with similar pile load tests in Thanet Sand.

Jan 1, 1989

By J. R. Thoenen

This circular is part 6 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cableway excavators, and hydraulic monitors; part 3, hydraulic, clamshall, ladder, and diaper dredges; part 4, haulage equipment, particularly industrial cars with locomotive or hoist as the motive power; part 5, conveyor belt, motor truck, pump and pipe line, towboat and barges, and aerial-trams haulage. This circular discusses the application of these various types of equipment to the different types of sand and gravel deposits and contains a reference bibliography. It completes the discussion of excavating problems.

Jan 1, 1936

By J. M. Simard, S. Morissette, P. Coursol, P. Mackey

A new, powerful model is presented that focuses on plant logistics and scheduling aspects of the smelting, converting, fire refining and casting operations at the Horne smelter. This plant complex is the largest custom copper smelter in North America. It handles a wide range of feeds and utilizes a number of proprietary continuous and batch technologies that require good scheduling in order to maximize plant capacity and efficiency. The present model was developed by Xstrata Process Support, in collaboration with the Horne smelter, and uses the Arena® software to evaluate the impact of a number of plant variables on the annual copper capacity of the plant. Model development was carried out by Xstrata Process Support, in collaboration with the Horne smelter, through the effective combination of process chemistry knowledge and detailed knowledge of the plant operation (including all material flows and transfers, as well as information such as operating on-line times, plant stoppages and also scheduled and unscheduled maintenance activities). A number of case studies were then examined, including the impact of anode furnace and casting cycle times on annual copper capacity and the impact of a one-crane mode of operation in the converter aisle, which normally operates with two cranes in service. The model predictions were found to match actual plant results very well. The present modelling of plant logistics and the scheduling aspects were found to add important dimensions at the plant with regard to projections of the real-life plant capacity. As demonstrated in the present case, this type of model and application can have a significant impact on optimizing operations at a given plant. This impact is particularly important in the current market environment, where emphasis is on maximizing plant output and lowering costs. These models can help yield the easily obtained gains that are clearly desirable in these times. Xstrata Process Support has developed Arena models for other operations and is available to explore new applications for a win-win situation at other plants, including mines and concentrator operations.

Jan 1, 2009

By Marcela Morvová, Mário Janda, Morva Imrich

"The possibilities of greenhouse gas mitigation using various methods are brought out. The special case of utilization of mixture of CO2 with other greenhouse gases in a synergetic way inside non-thermal plasma based system is described in detail.Measurements on pilot system comprising pyrolysis chamber as alternative energy system (production of hydrogen and liquid tar) were made for various biomass and waste as the input material. The exhaust from this system was treated with non-thermal plasma gap suitable for up to 650Nm3/hour of exhaust gas flow. Condensable portion of exhaust is liquefied in distillation unit; produced hydrogen is stored on-line inside nano sized carbon of our own production.The CO2 removal efficiency varies depending on exhaust composition between 45 to 98%. Other oxides as CO, NOx, SOx and several hydrocarbons and VOC are also removed. The main product connected with CO2 removal is a solid powder of proteinoid nature. There exist strong probability, that precursor of the origin of life on the Earth from primary atmosphere were formed in the similar way as it is present in the electric discharge system used. Our system is equipped with on-line as well as ex-post analysis of all forms of products. We have also developed a system for recuperation of all forms of produced heat. It is stored inside as latent heat of waxes.IntroductionNatural greenhouse effect on the Earth is caused mainly by water vapour with the average absolute concentration about 4%. Other gases able to absorb long-wave radiation and thus this causing greenhouse effect are CO2, CH4, N2O, halocarbons and as precursors ozone and NOX. Some of them we produce and introduce into atmosphere in large quantities during production of energy and in transport. This factor leads to permanent increase of average temperature of air, sea and oceans, so called global warming.Nowadays large amount of data exists showing that the temperature of Earth in the last 150 years has been continually increasing. It represents about 03°C per ten years and the most of climatologist believe, that the increased concentration of greenhouse gases in the atmosphere is responsible for this effect.The most important greenhouse gas is carbon dioxide CO2. Majority of CO2 emissions comes from electric power stations working with fossil fuels, cars and industry. Burning of fossil fuels contribute up to 80% to world wide anthropogenetic emissions of CO2."

Jan 1, 2010

By L. D. Roper

"This paper introduces novel comminution flowsheet concepts involving a novel apparatus, eccentric-high-pressure-centrifugal-comminution (eHPCC), and forthcoming advantages to the international mineral processing community. eHPCC is one-machine synergising high-pressure-rolling surfaces, high-intensity-attrition and centrifugal classification. eHPCC has demonstrated: an absorbed power- intensity of 4 MW/m3; receipt of lump feed whilst producing 80% of product particles less than (p80) 120 µm (choke-fed, dry, open circuit without grinding media; an inert comminution environment); tramp metal tolerance, and a minimum embodied-free-energy saving of 15% as compared against conventional comminution (this comparison withstanding 133-times difference in throughput). Furthermore, this paper introduces: process design and operating characteristics of eHPCC (wet, dry, with and without grinding media); reline considerations (vertical-lift without confined-space). The international mineral processing community is invited to consider eHPCC as an alternative to conventional comminution circuits and/ or complimentary so as to enhance existing process flow sheets.INTRODUCTIONEccentric-high-pressure-centrifugal-comminution (eHPCC) was conceived in 2013 (Patents pending) and has the potential to eliminate the in-efficiencies and complexity of conventional tumbling mill circuits. During the development and testing phase eHPCC demonstrated improved energy efficiency and sustainability offsets.eHPCC will compliment any upstream feed source, be it run-of-mine (ROM), primary crushed rock, or any other conventional comminution stream such as tumbling mill oversize. Another novelemerging technology, Conjugate Anvil-Hammer Mill (CAHM) (Nordell and Potapov, 2011), receiving ROM, will be a complimentary open-circuit feed to eHPCC for very high throughput flow-sheets.eHPCC may compliment downstream process requirements through selective mineral liberation. Selective mineral liberation is entirely feasible as the ore is comminuted upon itself (autogenously) in the high pressure zone caused by the synchronous rotating components."

Jan 1, 2016

By Norman F. Schulz

The technical excellence of separation achieved in a mineral concentration process, or any other process where two constituents of any kind are physically separated from each other, is expressed uniquely and quantitatively by the separation efficiency (E,): E. = (R - R,), where R is the percentage of the valuable constituent and R, the percentage of the waste appearing in the concentrate. The separation efficiency meets all the usual requirements of a true efficiency and is independent of the nature of the process used. It can be visualized as the percentage of the feed material that, in effect, actually undergoes complete separation while the rest of the feed is distributed randomly and unchanged into the two separation products. The problem of quantitatively assessing the results of a mineral concentration process recurs whenever one tries to decide which of two similar test results is more desirable. Although economic factors may greatly influence the eventual choice of process, they usually have very little to do with the technical excellence of a separation and are, therefore, not a consideration at this point. Concentrate grade and recovery, used simultaneously are the most widely accepted measures of performance, and if both the grade and the recovery are greater for one case than for another, the choice is simple. However, when the results of closely competitive operations are compared, it often occurs that one set of test results shows a higher grade and a lower recovery than another and the choice is no longer obvious. Laboratory investigations of a mineral concentration process applied to a given feed material can often be designed to yield successive paired values of concentrate grade and recovery over the practical range of the course of a separation process.' These results may be plotted as some combination of the cumulative values of grade, weight recovery, or unit recovery in the concentrate. The resulting correlations for two slightly different sets of conditions can then be compared qualitatively, or even quantitatively in particular cases.2 Such comparisons are not applicable, however, to individual concentration test results. The reduction of a separation test result to a single efficiency figure, preferably as a percentage of ideality, would afford the simplest and most precise means for comparing the results of competitive tests. The effective proportion of feed material that undergoes complete separation in any real concentration process, hereafter referred to as "separation efficiency," is such a figure. It is essily calculated from the usual feed and product data and can even be evaluated, in many cases, from data in publications describing various concentration processes. Mineral Concentration Processes and Their Evaluation Mineral Concentration Processes: The overall concentration process may be subdivided into a liberation process which severs the bonds between unlike mineral species, and a separation process, which sorts the resulting liberated particles into two products—a concentrate rich in mineral A and a tailing lean in mineral A. A perfect mineral concentration process is represented by the idealized scheme shown in Fig. 1 in which liberation and separation are not differentiated. The feed mixture consists of two mineral types which are completely liberated early in the process and then sorted by type. All the mineral particles of type A which respond uniquely to the selection forces acting in the ideal separator, report to the concentrate, while all the mineral particles of type non-A report to the tail-

Jan 1, 1971

By E. H. Boswell, E. M. Cushing

The Mississippi embayment east of the Mississippi River is part of a vast geologic and hydrologic province. The abundance of water available is largely responsible for the agricultural history of the area and is perhaps the key factor in the rapidly accelerating trend toward industrialization. The multiple artesian aquifer systems that underlie the region and the alluvial aquifer along the Mississippi River are virtually undeveloped sources of fresh water in that they are yielding only a fraction of the water available. The potential yield of the 12 aquifer systems is estimated to be about 25,000 mgd (million gpd) of which only about 600 mgd is presently being withdrawn. The amount of water in storage in these systems is about 1600 trillion gal. Ground water having a dissolved-solids content of less than 500 ppm is generally available at depths of less than 1000 ft, and water having a dissolved-solids content of less than 1000 ppm is available in some places to depths of more than 3000 ft. Iron is the most common troublesome chemical constituent in the ground water. Water in varying amounts is also available from streams within the region. The amount of water which originates within the region and which leaves it as streamflow during a year averages about 50 million acre-ft (about 45,000 mgd). An additional 375 million acre-ft (about 340,000 mgd), which originated outside the region, leaves the region as streamflow during an average year. Some streams have considerable flow during periods of no precipitation and the water during these periods generally has a low dissolved-solids content. Large quantities of water from streams and waterbearing sands (aquifers) are available in the Mississippi embayment east of the Mississippi River. Most of the region is underlain by aquifer systems that will yield large quantities of water to wells, making ground water the most readily available source of fresh water. About 90% of the water used in the region is obtained from wells. Streams have been used primarily to dispose of, and dilute, wastes that have been dumped into them. The Mississippi, Ohio and Tennessee rivers, and the lower parts of the Tombigee and Yazoo rivers also serve as a means of transportation. This nominally water-rich region receives from 48 to 56 in. of precipitation in average years and is crossed by several large rivers. The largest, the Mississippi River, is the western boundary of the region discussed in this paper. The economy of the region is basically agricultural, but industry has become increasingly important since World War 11. The diversification and mechanization of agriculture have resulted in a surplus of manpower, most of which is being absorbed by the expansion of industry. Further industrial expansion probably will occur because of the available manpower, natural resources and economical transportation. Increasing demands on available water supplies will be made and the future economic growth of the region will be largely dependent upon wise utilization and management of the water resources.

Jan 1, 1969

By R. Costantini

Long-distance transportation of solids by hydraulic pipelines holds promise of great economic benefits. In most mineral processing plants today, moving of solids in slurry-form by pipeline is commonplace. Yet in spite of this, the method is slow in being adopted on a broad scale for moving solids over distances of many miles. This is especially surprising in view of the successful realization of two daring ventures in long-distance solids pipelines in this nation within the last five years. One is the 72-mile long, 6-in. diam. pipeline of the American Gilsonite Co. which has been satisfactorily transporting 700 tpd of gilsonite from the mine at Bonanza, Utah, to the processing plant at Grand Junction, Colo., since April 1957. The other is the 108-mile long, 10-in. pipeline of the Pittsburgh Consolidation Coal Co., which has been transporting about 4000 tpd of finely crushed coal from the mine at Cadiz, Ohio, to the Eastlake Power Plant of the Cleveland Electric Illuminating Co. since January 1958.

Jan 8, 1961

By Arel B. McMahan

The U.S. Bureau of Mines investigated 21 mines, prospects, and mineralized sites in and adjacent to a 38,713-acre portion of the 255,058-acre Kingston Range Wilderness Study Area in 1983. The study area is 35 miles north of Baker, CA in the Mojave Desert. Mineral deposits in and adjacent to the study area are in altered carbonate rocks intruded by diabase sills near monzonite porphyry contacts. Monzonite porphyry forms the core of the Kingston Range and underlies about 70 percent of the study area. Sedimentary carbonate rocks are exposed in bands on the north and east boundaries and as isolated roof pendants in the southeastern portion of the study area.

Jan 1, 1986

In general, the metallurgical industry has so far been slower than the chemical industry to adopt ion exchange materials for industrial processes. The atomic energy industry presents a marked exception to this general situation, and the literature shows a rapidly increasing use of ion exchange techniques for the recovery of atomic energy metals on scales ranging from the ultra micro up to that of the largest mining operations. In many cases, the processes used would be equally applicable to more common metals and it is hoped that this review will be of interest to metallurgists outside the specialised atomic energy field. The review is intended to describe developments of ion exchange processes made during the last three years. Earlier studies have been summarised by Kunin and Preuss (1956) and Roland (1957). In order to restrict the number of references discussed, purely analytical procedures have been omitted and only those processes which have been conducted on a reasonably large scale or which, from their nature, areclearly capable of being upscaled, have been considered. The paper is divided into five main sections concerning respectively:Water treatment and effluent disposal.Metal recovery and purification.New ion exchange materials.New ion exchange equipment.Membrane cells.WATER TREATMENT AND EFFLUENT DISPOSALA high proportion of atomic reactors, and particularly those of American design, are cooled by water which is...

Jan 1, 1961