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Asarco's newest concentrator near Troy, Montana, began operation in October 1981, and is presently milling ore at its design capacity of 7,710 metric tonnes per day. The underground room-and-pillar mine produces a readily floatable copper sulfide- native silver ore in a quartzite gangue. Major sulfide minerals are bornite and chalcocite with minor chalcopyrite; fine grained native silver occurs with the copper sulfides. There are also minor amounts of native copper and copper oxides in the ore. A rougher copper-silver concentrate is floated, reground and cleaned twice. Cleaner tail is scavenged, and the scavenger concen- trate is combined with rougher concentrate for regrinding. Rougher flotation tailing and scavenger tailing make up final mill tailing which is disposed of by spigotting into a tailing dam located 10.5 km from the mill site.

Jan 1, 1978

The mill area of PT Freeport Indonesia is located in a valley surrounded by steep natural slope, characterised by extreme topography with mountains rising to above 4500 m within 100 km from the seashore. The valleys are deeply embedded into the mountainous terrain and bordered by steep natural slopes. Vertical or overhanging lime walls are interrupted by steep vegetated screen sections containing accumulated loose material from weathering processes and ancient rock falls and/or debris flows/avalanches. The climate can be best described as alpine subtropical with an accumulated rainfall of more than 5000 mm per year. Occasional snowfalls and superficial freezing above 4000 m elevation leads to heavy weathering of the superficial rock layers and along open joints and fractures. The mill area is a crucial and strategic infrastructure for the entire mining operation which is best characterised as a high density industrial area with facilities including water tanks, power generators, crusher, and concentrating facilities including office buildings and workshops as well as access tracks to the underground mining blocks. Considering the local topography, the restricted space conditions and the number of technical installations, the facilities are likely to be affected and highly vulnerable to rock fall from the surrounding slopes. In order to minimise the rock fall hazard three rock fence barriers area were constructed at the mill area. The 7.5 rock fence barriers were designed with the maximum capacity of 5000 kJ. These are the largest capacity of rock fall barriers ever constructed in Indonesia. The total length of the barriers for the three locations was 126 m. The biggest challenge of this project was the construction of the barrier at West Gulley, which was constructed at 300 m above ground level. For this site, construction access was undertaken using helicopter. This presentation discusses the design of the mitigation structures as well as the construction approach and stages of the barriers. Please note: This paper is abstract only.

Nov 25, 2010

By D A. Williams, P J. Chapman

Constructing upstream raises with tailings is an accepted and cost-effective practice in Western Australia, where the climatic conditions are favourable, desiccation (and hence overconsolidation) occurs rapidly due to air drying and there is a perceived low seismic risk. This is in contrast to many other settings, where there is either a positive water balance, high seismicity or a combination of both. In recent times, there has been an increased focus on seismicity in areas of Australia that have historically been considered to be of low seismic risk. The increased focus is driven by two recently published documents used by tailings practitioners and increased awareness from corporate entities, particularly those with mines in high-seismicity regions such as South-East Asia and South America (particularly Chile).The increased awareness has resulted in increased rigour being applied to seismic design of tailings storage facilities (TSFs) in general, and particularly upstream-raised TSFs. This paper compares the results of a seismic stability assessment for an upstream-raised TSF located in the Goldfields region of Western Australia, which has historically been considered a low seismic area, with a seismic stability assessment carried out for a crossvalley TSF containing similar tailings but located in a high-rainfall, high-seismic setting in South-East Asia. The influence of the adopted design earthquake values on the results of the assessments and the potential impact of the maximum design earthquake (MDE) on the design approach is presented for both cases. The results indicate that although the Western Australian site is located in an area thought to have low seismic risk, the screening level analyses suggest that the MDE could result in liquefaction of the tailings materials. Not surprisingly, liquefaction was also indicated for the South-East Asian site. The outcomes of the assessment are also presented.CITATION:Chapman, P J and Williams, D A, 2015. Seismic design of upstream-raised tailings storage facilities in a semi-arid, low-seismicity setting, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 157–162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Williams RC

Overlying the coal deposits of the Sydney Basin are several lakes and other bodies of water. These include the Pacific Ocean, Lake Macquarie, the Tuggerah Lakes and the stored waters of the dams of the New South Wales Metropolitan Water Sewerage and Drainage Board. The coal beneath these bodies of water amounts to hundreds of millions of tons. Colliery workings have approached these areas of water and in some instances first 1"orkings of bord and pillar have taken place oi_eshh the water. he problem which now faces mine manage- and other interested authorities involves the determination of the maximum ;mount of coal which can be safely extracted from beneath the water. There are many factors to be considered including the depth of cover, seam thickness, geological details and strata movements.

Jan 1, 1972

Coeur d'Alene Mines is a precious metals producer which is dedi- cated to growth through it's exploration and acquisitions efforts. We foster and support these activities by providing our staff with long-term financial support, the encouragement to proceed with their projects and ideas, and a firm belief that we will be successful. Coeur's corporate headquarters are located in beautiful, historic Coeur d'Alene, Idaho. Our main mining operations are Rochester, locate near Lovelock, Nevada, Coeur Mine,located near Wallace, Idaho, and Thunder Mountain, located in central Idaho. Our Ken- sington Gold project is located about 45 miles north of Juneau in southeast Alaska. We have exploration offices located in Reno, Nevada, and Santiago, Chile. At this time, Coeurd'Alene Mines produces precious metals from mines located in the United States. Our Rochester open-pit opera- tion, which is 100 per cent owned and operated, is located in Nevada. Presently, this operation produces 5.5 to 6 million ounces of silver per year and 60-70,000 ounces of gold. We move 65,000 to 70,000 tons of rock per day of which about 23,000 tons is ore. The ore is crushed, stacked on permanent heaps and leached. The recovery is by Merrill-Crowe. Although the average grade is rela- tively low, 1.4 ounces per ton silver and 0.012 ounces per ton Au, the operation is very low cost. Our cost of production is less than $4.00 per silver equivalent ounce. Rochester is anunusual operation in that the crushed rock stacks without much compaction and the ores are easily leached. The final height on our heaps will be about 220', and overall recovery will be about 55 per cent of the silver and about 85 per cent of the gold. Reserves at Rochester are expanding and are now adequate for at least fifteen years of opera- Tion.

Jan 1, 1991

This report chronicles the historical development of longwall mining in the United States and speculates on future developments to the turn of the century. Five eras of technological development during the modern period are described and analyzed. These eras discuss the development of (1) mechanized extraction, (2) self advancing roof supports, (3) high capacity roof supports, (4) shield supports, and (5) system automation. Current trends are analyzed in terms of: longwall utilization, production capability, 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

Landscape interpretation, geology and mining history are being successfully used to explore options for sustainable community tourism product development. Recent work by the author in Europe and Australia has indicated the value of adding and producing interpretive information about mine and quarry locations û both active and inactive. This work has allowed for the branding and development of new sustainable community tourism products based on the landscape, folklore, mine and geological heritage. Communities in rural areas are seeking new opportunities to sustain their local economies. Using a relatively new phenomenon called geotourism as a starting point, they have developed themed products connected to walking/cycling guides, interpretive panels and visitor centres. These themes can be linked to geology, archaeology, botany, local history and to industrial heritage sites such as old mines, to generate local employment. This new geotourism approach has successfully brought a new and greater audience to discover the value of geology and mining history. Communities have established a unique place for themselves within the tourism marketplace using the geotourism brand. Other communities with an established tourism product are also now using geological and mine heritage via geotourism to rebrand and meet changing global trends. The geotourism approach has allowed for positive collaboration among communities, service providers, local and government authorities to channel tourist revenues into rural communities. The pooling of resources under the banner of geotourism has led to cost-effective marketing, targeting and promotion of products using multimedia and web sites. Geotourism has emerged strongly in Europe, North America and China in the last decade. The Australian minerals industry now has an opportunity to implement this new branding concept to assist and benefit the communities in which they run their activities. Communities can also take advantage of the potential to develop a sustainable geotourism business around a past or present mineral industry in their vicinity.

Jan 1, 2009

The basic make-up of the majority of currently produced bulk explosives has changed little in the last 20 years. These explosives would be described as mature in a life cycle analysis. Therefore these explosive products and the practical rules for their use are well understood and well established. In recent years there has been interest in low density explosives, predominantly due to ammonium nitrate shortages and the associated increase in the cost of explosives. In the use of low density explosives some of the practical rules for the more commonly used bulk explosives do not apply. Therefore a shift in the thinking among users is required. At a number of mines low density explosives have been trialled or are being used, utilising the practical rules that apply to bulk explosive products. This has led to poor blast results in many situations. These poor blast results have often then led to a reduction in the use of low density explosives at the mine. This reduction does not acknowledge the advantages that can be gained from this product in the area of reduced cost of mining. This paper looks at low density explosives and discusses how and why these products work. Included in the paper are some practical ideas and examples of how low density explosives can be effectively used at the mine site.

Jan 1, 2007

By M D. Griffith

Oct 12, 2022

By M Haest, S Sandler, R Botha, H Lang, K Hume

Benchmark practices in the mining industry include the establishment of Quality Programs — Quality Assurance and Quality Control (QAQC) — to monitor the correct execution of sampling protocols and control each stage of the ‘Sample Cycle’: Sample Collection, Preparation (comminution) and Analysis. QAQC reports commonly include statistical-numerical results that quantify performance of QAQC controls (field duplicates, preparation duplicates, blanks, standards etc). Graphics such as scatter plots, QQ plots, histograms and cumulative frequencies are used to represent the results. Statistical values including relative difference, absolute difference, relative variance, averages, T-test, and Zscores are used to quantitatively express the relationship between duplicate pairs ... but is an effective quality program just a statistical exercise? This paper aims to highlight the concept of ‘Quality Management’ (QM) as the precursor of continuous monitoring (ideally in real time) of QAQC results on Exploration, Production, Processing and Port samples, determined by trend analysis performed on a time and/or grades basis. Currently, there is a paradigm in the process of quality assurance that if individual data points fall within a predetermined acceptance limit then they are ‘acceptable’ and therefore suitable for informing operational and investment decisions. However, what is stated with respect to QM is that sometimes results found within the acceptance limits can indeed be internally biased, or show material deviations over a period of time, thereby impacting reconciliation results and/or potentially creating discrepancies with the final buyers. QM refers to the proactive detection of these ‘anomalous tendencies’, the approach and communication with the source of the information, the understanding of the reasons that cause the deficiencies, and the generation of agreed action plans to remediate the situation and ensure the consistency of results, in other words: continuous improvement on proactive manners.

Mar 22, 2022

By C Catania

Mining companies and operations across the globe typically target best practice financial management, along with a focus on economically driven mine plans. Not only is this inherent in running a successful mining business, but also critical in addressing investor scrutiny. The standards for social and environmental practices is less consistent than this, with most companies adopting standards that are driven through legislative and compliance requirements of the nations in which they operate. Although there is still room for improvement, Australian is a country that stands at the forefront of social and environmental legislation, driving more sustainable planning practices for mining operations, with an ever-increasing focus on mine closure considerations. Of the many nations yet to reach such a legislative position, Kazakhstan is a place where some companies are driving towards world class standards beyond what is government mandated. CITATION:Catania, C, 2018. World-class mine planning for a sustainable future in Kazakhstan Mining, in Proceedings Life-of-Mine 2018, pp 6–7 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By H R. Pein

"The Corridor Sands deposit is situated approximately 190 km north east of Maputo, Mozambique adjacent to the paleo-mouth of the Limpopo River. This deposit is one of the worldÆs largest known economically viable resource of titanium, accounting for approximately one third of the global resource. As part of the pre-feasibility and feasibility study for development of the Corridor Sands project, various geological and geotechnical investigations were undertaken, selected results of which are presented in this paper. These investigations have enabled a detailed understanding of the material characteristics of the orebody as well as the tailings materials, such as the fines, to be developed. These material characteristics have had a significant impact on the selection of the mining and disposal methods currently being implemented."

Jan 1, 2001

Traditionally, surface coal mines in the Western United States have been limited by economics to depths between 150 to 200 feet. Utah International Inc., however, is now planning to strip coal its San Juan Mine in Northwestern New Mexico to depths ranging up to 400 feet while uncovering 20 feet of steam coal. This method is cost-competitive with nearby shallower coal deposits and underground mining of the same property. How trucks and shovels can pre-strip for a dragline, along with results of the planning process, comparison with alternate systems, capital requirements, operating costs and comparisons with other coal sources are all detailed. Also discussed are the major problems anticipated, how they might be corrected, and potential improvements to the concept. Introduction The San Juan Deep Stripping Project will be situated at Utah International's San Jean Mine. The mine is in the Four Corners region, so-called because four states enjoy a common border point about 30 miles to the northwest.(see Figure 1). The area is a semi-arid plateau region with an average elevation of 5,200 feet, receiving an average of 6 inches of precipitation annually

Jan 1, 1981

The "Line of Lade", a generic term by which the great Broken Hill orebodies are collectively known, lies in the County of Yancowinna, New South Wales (NSW) at the south eastern extrenity of the Barrier Ranges. As the township of Broken Hill grew to a city (incidentally it was officially named Willyama but by exerting an enterprising community independence which is still evident today it outplayed officialdom and retained its descriptive name), two major areas of population developed, Broken Hill and South Broken Hill. These two main civic divisions are respectively north west and south east of their dividing line, the surface expression of the orebody. See Fig. 1. The border between the States of NSW and South Australia (SA) is drawn along longitude 1410 East whilst the city of Broken hill's official longitude is 1410 28' 14" East which means it is only 50 km from this political boundary. A latitude of 310 57' 03" South contributes to the harsh climate of high summer temperatures which is not mollified by any significant increase in altitude for Broken Hill is only 300 m above sea level.

Jan 1, 1983

There is an established need for an inflow of foreign capital if New Zealand is to meet projected growth rates. The Government recognises this and encourages capital inflows especially where there are allied economic benefits such as the access to specialised know-how or export markets. The Government has promulgated certain Regulations which are administered by the Reserve Bank. Under the Capital Issues (Overseas) Regulations 1965, consent is required before any company incorporated overseas can commence business in New Zealand or before an overseas person can borrow or raise any money in New Zealand. A New Zealand company is deemed to be an overseas person if more than 25% of the voting power is held by non-residents. In terms of current policy, overseas companies are permitted to borrow in New Zealand only a limited amount of working capital and some longer term capital calculated on the ratio that their New Zealand owned equity capital bears to their overseas owned equity capital. Wholly owned overseas companies are expected to bring all of their Fixed term capital from overseas.

Jan 1, 1971

Average annual growth in consumption of primary energy in Australia over the past 10 years has been 5·5 per cent compared to a world average of 4·1 per cent.Over the next 10 years growth rate is expected to increase to 6 per cent per annum due largely to the rapid development in the mineral processing industry.By the end of the 19705 natural gas is expected to supply more than 9 per cent of Australia's primary energy market. Coal will supply 40 per cent and petroleum products 47 per cent. Nuclear energy will make its appearance but will make only a small contribution in the period.Australia has adequate reserves of natural gas and coal to supply its needs in the 1970s and beyond. However the newly developed reserves of crude oil, while supplying 60-70 per cent of requirements in the initialyears, will need regular and sizable additions if they are to keep pace with the expanding consumption. For Australia to become self sufficient in the period 1970-1990 it is estimated that new discoveries will need to approximate ten times the volume of recoverable reserves found in Australia to date.

Jan 1, 1971

By K Rau

The overall success of a mining operation is directly impacted by the reliability and availability of mining equipment. Heavy-duty vehicles such as excavators and haul trucks are used for conveying of bulk material and improving such assets’ availability helps reduce costs, increase throughputs and improve safety (Ravande, 2022). If a mining operation’s key performance indicators (KPIs) are tied to operational performance, then overall equipment effectiveness (OEE) is an essential metric to track progress and to identify areas of improvement.

Sep 1, 2024

The emergence of a new range of database communication standards and software has provided the impetus for the development of a new approach to exploration and mining data management. The acQuire software produced by acQuire Software Pty

Jan 1, 1998

Historic mining across the Bendigo goldfield reached an average mining depth of 750 m over an area of about 16 km by 4 km, with two shafts exceeding 1400 m. Mining ceased in the mid 1900s due in part to increased dewatering and ventilation demands. Water extraction technology of the day, combined with multiple mine ownership, did not allow uninterrupted and thus economic mining activity to prosper. Today Bendigo Mining Limited (BML) is targeting gold-bearing reefs beneath the water-filled historic mine workings. To ensure mining activity can proceed without the risk of water inrush, historic workings are being dewatered by submersible pumps in historic shafts and through a series of underground drain holes intersecting old workings. Due to the high heads involved, individual drain hole development requires rigorous safety control implementation and assessment prior to drilling. Water extracted via drain holes is pumped to the surface through a series of pipe lines and rising mains in conjunction with two staged pumping stations. Both stations are equipped with high-speed centrifugal pumps, each capable of pumping 40 L/s at a static head of approximately 300 m. BML, which operates beneath and within a large city, is confronted with unusual environmental and social challenges compared to many within the mining industry. The raw mine water, which contains elevated salt levels, is piped through residential areas and must comply with strict controls to prevent impacts on the surrounding environment. The final delivery point is BMLÆs water treatment plant at the north end of the city. The water treatment plant utilises chemical pretreatment and reverse osmosis. It is able to process 7 ML of mine water per day at full production. The product is approximately 5 ML of reusable irrigation quality water, which is made available to the Bendigo community for public gardens, sporting facilities and rural irrigation. The 2 ML of brine is directed to a purpose-built evaporation pond facility located 7 km north of the water treatment facility.

Jan 1, 2008

By Singh RN

The Bulli Coal Seam, located in the Illawarra Coalfield of New South Wales, has a long and varied history of sudden outbursts. From available information this problem has resulted in twelve fatalities over the last one hundred and one years, with over five hundred separate outburst incidents being identified. These incidents have varied in severity and intensity from the discharge of 1 to 2 tonne of coal, with a slight increase in gas emission, to the discharge of 200 to 400 tonne of coal with some 6,000 m3 of gas being liberated and large items of mining equipment being pushed 1 to 2 metres down the roadway.Geological features associated with these outbursts can be mapped on a regional and mine by mine basis, to provide some indication or warning. Similarly changes in gas content and gas composition can also be determined on a regional and mine by mine basis. However sudden geological changes (such as a 6.5 metre seam displacement within 15 metres) variations in gas content (such as 6 m3/tonne to 15 m3/tonne) and changes in gas composition (from 95% CH4 to 90% CO2) all within one mine does make the prediction or forecasting of outburst incidents exceedingly difficult.

Jan 1, 1998