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By E Apaza, R Neumayr

This paper aims to summarise the discovery of the QTS Central resource, a previously unidentified +1 Mt inferred resource that lies between two major CSA resource systems.The 1.7 Mt at 5.76 per cent Cu, QTS Central ore system represents 1/6th of the CSA mineral resource and was discovered in 2014 based on the accumulation of historic exploration records dating back to 1989.The CSA deposit consists of five ore systems hosted within turbidite-derived siltstones (CSA Siltstone) and lesser sandstones (five per cent) of the Devonian Amphitheatre Group. The host sediments strike approximately north–south with a steep westerly dip and exhibit a well-developed east dipping cleavage. Most CSA mineralisation is hosted within dilation zones at the intersection of cross-cutting structures and is interpreted as epigenetic in origin.Alteration and weak mineralisation, up plunge to the reported QTS Central mineral resource, was initially detected in 1990 during a downhole electromagnetic conductivity (EM) study, where one hole indicated an off-hole conductor, later tested with four diamond holes. One of these diamond holes intersected 3 m at 7.5 per cent Cu at 200 m. Development of the 9070 Subway drive in 2005/2006, linked the QTS North and QTS South workings and intersected structures interpreted to host QTS Central mineralisation. Subsequent drilling proximal to the 9070 Subway in 2007 identified an up plunge extension to the QTS Central zone (UDD07152: 1.8 m at 6.3 per cent Cu from 10.7 m). Work on QTS Central was largely forgotten until 2012 when the mining of a 450 m infrastructure drive provided a platform to test the anomalous grades. In December 2013, drill hole UDD13055A intersected 20.9 m at 7.2 per cent Cu from 378 m. By the end of 2014, the QTS Central inferred resource was 1.0 Mt at 6 per cent Cu and 18 g/t Ag (Hosken and Apaza, 2014). Late in 2016, further infill drilling occurred from two fronts to increase confidence in the QTS Central resource. The results of this drilling are expected late in 2017.The current interpretation indicates the QTS Central system consists of two main lenses hosted within closely bedded sandstones and siltstones. The sandstone in general is not mineralised, being heavily silicified, while the siltstone is mineralised and chloritised. The main mineralised lens is 75–200 m along strike and 450 m high. Massive sulfide feeder structures lie at the core of the two main lenses, although the characteristics of the QTS Central system tend toward the mineralisation being more chlorite-rich than in QTS North and QTS South.CITATION:Apaza, E and Neumayr, R, 2017. The discovery of the QTS Central ore system, CSA mine, Cobar, NSW, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 151–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Energy Savings and Technology Comparison Using Small Grinding Media Considering the complexity of minerals, the need for finer grinding is increasing along with the energy cost. However, energy is increasing exponentially when grinding finer with conventional grinding balls. The use of small grinding media represents the best potential to improve energy efficiency. Today, it is possible to use grinding media as small as 1 mm. How do they perform in industrial grinding mills? The use of small grinding media (5 - 12 mm), called Millpebs, in regrind mills proved that finer grinding can be achieved at lower energy consumption. In ball mills, energy savings vary from 10 per cent to 40 per cent compared to 25 mm media. A regrind ball mill with a mix of small grinding media can be as energy efficient as an Isa Mill charged with 2.5 and 3.5 mm beads. In vertical stirred mills, energy savings vary from 30 per cent to 60 per cent. To carry out the same final grind, a vertical stirred mill with Millpebs will consume at least 60 per cent less energy than a ball mill using 25 mm grinding media. More potential savings were identified. To achieve those improvements, some operating conditions must be met: 1) feed size should be less than 250 ¦m; 2) the pulp must be fluid enough; 3) finally, the slurry linear velocity should not be excessive. This paper talks about all those industrial results improvement and operating conditions.

Sep 13, 2010

By W. M. Dressel

In producing feed for a lead blast furnace, concentrates analyzing 70 to 80 pct Pb are sintered to produce a physically acceptable low-sulfur product which contains only about 50 pct Pb. Mixtures of PbS with varying amounts of SiO2, CaO, Fe 20., and ZnS were heated in an oxidizing atmosphere at 1,000° C; the products were cooled and examined to determine the problems involved in producing sinter with substantially higher lead levels. Microscopic and electron microprobe studies of the above products as well as experimental and commercial sinters indicate that sinters consist essentially of lead silicates, lead-zinc silicate, calcium zinc silicate, and spinel (ferrite). Lead oxide and lead sulfate areas appear to result from insufficient mixing of the materials prior to sintering. The data give an insight into the process and show that sintering results from a complex interaction of all constituents and that sintering is not simply a matter of diluting the mixture to control the oxidation of lead sulfide.

Jan 1, 1975

By Walter B. Lenhart

This paper is one of a series on milling methods and costs being. published by the Bureau of Mines. The milling practices and special problems relating to grinding, tailings disposal, and choice of a treatment process at the Cardinal mill are discussed. The property of the Cardinal Gold Mining Co. is about 18 miles southwest of the town of Bishop, Inyo County, Calif., at an altitude of approximately 8,500 feet. The camp has been designated Bishop Creek by the postal authorities. The property comprises 33 mining claims, including fractions and millsite in sections 19, 20, 29, and 30, T. 8 S., R. 31 E. These claims are located in a general way along the strike of a band of quartzite.

Jan 1, 1938

By Art Cooper

Granulation systems are customarily viewed as problem areas in metallurgical operations. The inherent risk of explosion when combining a high temperature melt with water creates a safety hazard. Separation of the granulated material from the quenching medium generally involves equipment that can have significant maintenance and operating costs. Granulation systems' reliability and availability can negatively affect the plant production. Against this background, granulation systems have been treated by design firms and producers as an add-on and a necessary evil. The technology is becoming better understood and solutions to common problems are being found. This paper will discuss typical problems in common systems, and some of the improvements that have been made, with particular reference to non-ferrous applications.

Jan 1, 2006

By R J. Norris, D J. MacKenzie

Gold-bearing veins have formed at a wide range of depths throughout the uplift history of the Otago Schist. The earliest gold mineralisation occurred during the later stages of Mesozoic metamorphism. This mineralisation was characterised by diffuse wall rock alteration with greenschist facies metamorphic or retrograde metamorphic mineral assemblages, and gold occurs in this altered rock. Quartz veins formed in .steeply dipping extensional fractures associated with this mineralisation type strike north to northeast. The Macraes mine exploits this deposit type. The present northwest strike of the mineralised zone at Macraes is a result of post-mineralisation deformation of the schistosity-parallel mineralised shear zone which hosts northeast striking extensional veins. This combination of schistosity-parallel shear zone and steeply dipping northeast striking veins may exist elsewhere in Otago, and this deposit type is most prospective. Steeply dipping quartz veins formed during post-metamorphic un-roofing of the Otago Schist strike northwest to west and occur as clusters of near-parallel structures in east and central Otago. These veins consist mainly of massive quartz, although some prismatic quartz occurs also. Breccia fragments in veins are common and these are generally silicified, with some gold. Wall rock alteration is negligible, and vein margins are sharp. A set of middle Tertiary veins occurs in northwest Otago. Most of these also strike northwest and dip steeply, but some strike northeast. These veins contain abundant ankeritic carbonate as well as quartz. The carbonate pervades adjacent wall rock as veinlets, but gold mineralisation is confined to veins. Quartz is commonly prismatic and vuggy, and contains gold, which is commonly coarse grained especially in silicified breccia zones. Associated veins contain stibnite. This vein type formed close to the paleosurface (>2 km). Mineralised veins in Marlborough currently strike northwest, but these have been rotated from northeast strike during Alpine Fault displacement of Marlborough from Otago. Some of these veins were formed under late metamorphic conditions and are similar to the north to northeast striking veins in Otago. As in Otago, this type should be considered to be most prospective if they have associated schistosity-parallel shears.

Jan 1, 2000

By Eugene T. Sheridan

The 24th annual survey of the peat industry by the Bureau of Mines, United States Department of the Interior, revealed that 76 producers in 20 States reported commercial production of peat in 1957. In addition to the States that reported production in 1956, Colorado, Idaho, and Wisconsin produced peat in 1957 Forty-four producers reported humus production; 21, reed-sedge peat; and 22, moss peat production. This total exceeds the number of active plants but several producers recovered more than one type of peat. Fifty percent of the total production was reported as reed-sedge peat, 36 percent as humus, and 14 percent as moss peat. About one-sixth of the total production was raw peat, with no preparation other than being air-dried. The remainder consisted of processed peat prepared for use by cultivation, shredding, and/or kiln drying.

Jan 1, 1958

The development of an onboard contaminant diagnostic monitor to continuously measure contaminant level in a mining machine was advanced to a prototype stage in this contract. Several concepts were investigated and it was found that a static spool type sensor was the most reliable and accurate. Laboratory and field tests showed that an instrument based on this concept is capable of measuring contaminant levels and/or size distribution, depending on the configuration of the sensor. Moreover, this instrument can function on emulsions or homogeneous fluids. Current laboratory equipment can operate on homogeneous fluids only.

Jan 1, 1983

By L A. Maslov

We have considered the following characteristics of the crust and upper mantle of the Pacific Belt: seismic wave velocity anomalies, mechanical stress and shear deformation rate fields, heat flow and the pattern of metallogenic provinces of the Belt. It has been noted that there exist certain .regularities in distribution of the above mentioned geophysical characteristics and metallogenic zones within the Belt, displayed by prevalence of the lithophile elements in the Asia-Australian part of the Belt, and of the chalcophile ones within the American part.

Jan 1, 1995

By Jerry B. F. Champlin

The successful injection of liquids into subsurface permeable formations for production stimulation, storage, or waste disposal requires a rapid, precise, and accurate method of determining the permeability of porous solids. This report describes a method and apparatus, developed by the Bureau of Mines, that use the principle of specific-volume permeametry. Calibration of the apparatus over a wide range of permeabilities and standardization of several apparatus constants have eliminated many of the tedious calculations and problems of manipulation common to some other methods. Improvements in reproducibility and accuracy have resulted from reducing experimental measurements to one parameter--time. Specific permeabilities of reservoir rock samples are determined directly from a chart that relates elapsed time to a permeability equivalent to that determined by bubble-tube measurements.

Jan 1, 1962

By Marco D. Boscardin

Control and mitigation of building response to construction activities are assuming a greater role in design decisions for underground construction. Alternatives for controlling building response have multiplied with the continued development of ground modification methods, better control of construction activities that cause ground movements, and increased understanding of building behavior and response. This paper describes approaches to estimating building response to construction-related ground displacements caused by adjacent excavation and highlights the discussion with several case history examples. Examples discussed includes experiences with two, seven-story historic structures, supported by timber piles with granite block pile caps, which were underpinned in preparation for ground-freezing ground stabilization and tunnel construction beneath the buildings. The elevation of each building column was monitored and elevation adjustments were actively performed during construction. The second example examines the performance of a slurry wall braced cut, 45 to 50 feet deep penetrating through a stiff crust into a soft clay layer and associated building response. This cut was immediately adjacent to two, approximately 15-story office buildings, which were supported by deep foundations founded in the stiff crust.

Jan 1, 2003

By A. E. Halim, J. F. Brune

The 2006 Sago, Darby, and Aracoma mine disasters in the United States (US) forced the US government to implement the 2006 MINER Act and additional regulations that require all US underground coal mines to install and maintain refuge chambers to manage entrapment emergencies, in particular, fires and explosions. However, there is a debate on whether barricading in refuge chambers is a good strategy to survive such emergencies. Australian coal mines are not required to use refuge chambers and, instead, have adopted a strategy that focuses on instructing and training miners to self-escape to the surface. This paper analyzes merits and problems of using refuge chambers and self-escape to the surface to manage emergencies in fires or explosions in an underground coal mine. The authors found that the use of refuge chambers may not be the best strategy during extensive fires or when multiple explosions happen. In these situations, mine rescuers are unlikely able to extract miners who are sheltered in chambers and conversely, self-escape may save more lives than sheltering. Chances for successful self-escape are further improved by regular, externally assessed training such as Level 1 Emergency Exercises required in the Australian State of Queensland. These exercises put pressure on mine operators to ensure and maintain the effectiveness of their emergency management system.

By P Storey, B Deans, T Lancaster

Straits completed its Feasibility study on the Whim Creek Copper Project in 1996. At this stage WCCP provided Straits with an open pit mine - heap leach - SX-EW copper project to follow on from its successful Girilambone Copper Operation (GCC). Since this time Straits has continued to review WCCP investigating a number of development and production scenarios. The development of Whim Creek, early 2004 and is on schedule to commence copper production in the final quarter of 2004. On current reserves Whim Creek will produce approximately 17 000 tonnes of copper cathode per annum for three to four years, at cash costs of The paper will cover a general description of the project, the project development and key design issues. Additional construction related issues associated with the complete relocation of the GCC plant to Whim Creek will be covered in the conference presentation.

Jan 1, 2004

This study assesses whether Narragansett Basin coal deposits could be developed commercially in the near future. To do this, we identify the potential market for the coal, assess the price these users would be willing to pay for Narragansett coal, and this price to the expected costs of producing Narragansett coal. The study concludes that the major market, New England utilities, could burn bituminous coal from Pennsylvania or West Virginia at a lower total cost than Narragansett Basin coal, assuming expected mining conditions and emission policies. Therefore, the study concludes that Narragansett Basin coal resources could not be developed economically in the next ten years.

Jan 1, 1979

By A. Mazhary

"Although ore sorting in mining is not a new concept, sensor-based sorting has failed to gain broad acceptance due to perceived challenges with the technology. In order to gain wider applications, this research focuses on treating waste rock and low-grade ore to identify and test appropriate sensors and to evaluate the response. Results showed that amenability of rocks to sensor-based ore sorting is both sensor and ore specific. It was also observed that the efficiency (recovery) of sorting is directly influenced by the degree of heterogeneity of the rocks. The overall outcome showed that with the right sensor, several of the materials tested are amenable to sensor-based ore sorting. Mining companies could benefit from multiple economic and design impacts, such as lower energy cost, lower transportation costs, higher metal recoveries and smaller footprints that lead to more sustainable mining. This paper will focus on the effects of heterogeneity of rocks on sorting potential and efficiency.IntroductionSensor-based ore sorting has been attracting more attention since the pressure for effective resource extraction and management has increased. An urge to make most of the current deposits, and to make the low-grade deposits economic to mine has ushered the technology to find new ways to overcome the new challenges. No matter the terminology used, such as coarse beneificiation, waste rejection, particle or bulk sorting, the purpose of sensor-based ore sorting is to remove low-grade rocks before the comminution circuit, increasing the feed head grade and quality while reducing the energy costs related to comminution.Despite nominal advantages, there have always been some concerns that have impeded the intorduction and acceptance of the technology. One of the most important shortcomings of ore sorting is their capability, or capacity, to keep up with the high-tonnage mining. Some other issues that have been mentioned as drawbacks to sorting include installation cost of such devices, feed preparation for effiecient sorting along with accuracy of sorting and probability of false negatives (Manouchehri, 2003)."

Jan 1, 2015

This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1985 (October 1, 1984-September 30, 1985) under its Health and Safety Technology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau's overall goal of providing the system technology required to create a more healthful and safer working environment for the Nation?s mining and minerals processing workers.

Jan 1, 1985

By Paul V. Mullins

Review and evaluation of all available data on the vapor pressure of car-bon dioxide at the ice point, including previously unpublished results obtained by the Bureau of Mines, are presented. Suggested corrections and adjustments to all the data yield an average value of 26,136.4 mm mercury. Indicated agreement is within plus 1 part in 8,000 to minus 1 part in 11,000. A novel pressure bomb in which a sample of pure carbon dioxide is placed and sealed by a diaphragm fluid separator and its use as a reference pressure standard for extended and repeated use in the calibration of deadweight gages is described.

Jan 1, 1966

By Alice M. Chieruzzi

This Country Documentation Report presents the development of economic indices for Zambia for the period from 1970 through 1981. The work done through the Bureau of' Mines, Minerals Availability Program, under Contract number J0225001. This contract calls for the development of twelve index time series describing factor input costs in the mining sector of 95 countries. The twelve index time series describe the costs of: 1) mining wages, 2) construction wages, 3) equipment and repair parts, 4) bits and related steel, 5) timber and lumber, 6) fuel, 7) powder and blasting agents, 8) tires, 9) construction materials, 10) industrial materials, 11) transportation, and 12) electrical power. These indices combined with weight factors being developed by the personnel of the Minerals Availability Field Office (MAFO) of the Bureau of Mines in Denver, Colorado, will be used to perform instantaneous updates of all costs relating to the mining industry. The indices were developed primarily for use in the Bureau's Minerals Availability Program in assessing the worldwide availability of nonfuel minerals.

Jan 1, 1983

By G. Lipsett, S. Dessureault

Information technology (IT) initiatives in the past have tended to be sold on their ability to maximize resource output and return on capital by allowing assets to be used more effectively and efficiently. Many IT projects fail, not delivering return on their investment. This is known in the IT industry as the “productivity paradox,” where increasing investments in IT do not result in comparable increases in productivity. Experiences and studies of most business sectors reveal that this paradox is rooted in the false assumption that more IT spending automatically results in financial benefit, whereas the benefits are in how effectively IT is used. Most business sectors have accepted that re-engineering of processes is required to gain the full benefits promised of IT. A mining operation has organizational processes similar to most business sectors, but unique operational processes. The lessons of changing business practice in more common business processes, such as inventory control and customer-supplier relationships, can be adequately transposed into a mine setting. The unique operational processes in mines, in turn, require unique redesign efforts. Several enabling information technology opportunities have recently become available, such as more integrated mine production management systems and tactical manager training simulators. This paper reviews some of the latest IT products and outlines the processes and kinds of change that will be required in order to benefit from these new investment options.

Jan 1, 2009

By Fred P. Giese

Southeastern reserves of titanium ores are large, widespread, and ample for anticipated demand. The leading titanium industries are mining and beneficiating sand deposits, principally in Florida, and manufacturing titanium pigments. Most of the mineral output is consumed by the producers themselves. In 1962, 20 percent of the national pigment capacity was in the Southeast.

Jan 1, 1964