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Jan 1, 1987

The green field site is one that has no history of mining and as such it presents the designer with a blank canvas, on which any number of drill and blasting options can be drafted. No matter which mining method is selected all technology and experience will need to be acquired from outside sources, applied quickly and produce the right results. North Limited, in joint venture with the Sumitomo Group (20 per cent), have developed AustraliaÆs first block cave mine at Northparkes in New South Wales, Australia. This innovative and large scale mining project was taken from a green field site in November 1993 to a fully commissioned block cave mine in December 1997. NorthparkesÆ Endeavour 26 mine is now producing at a rate of 3.9Mt per annum from a 27Mt ore block. Prior to 1993 no history of mining activity existed at Northparkes. The rock had never been blasted and many questions were raised about how it would behave. While it was clear that the Endeavour 26 (E26) orebody contained geotechnical properties appropriate to block caving, the blasting methods required to establish a block cave mine had never been used in Australia and no designs were available. The joint venture partners had no prior experience with block caving and it was immediately apparent that this blasting technology would have to be acquired from foreign sources and applied to the unique local conditions. Conceptual designs for the block cave drill and blast were first drafted in 1994, first issued for drilling in December 1995 and first blasted in January 1996. 470 km of drill metres and four million tonnes of rock were blasted to complete the undercutting project by September 1997. This paper will provide those developing new drill and blast projects with an inside view of how one small technical team solved many design challenges to successfully construct AustraliaÆs first block cave mine under strict quality controls and ambitious time constraints.

Jan 1, 1998

By Heikki Jalkanen

The mineralogical composition and morphology of solidified copper smelting and converting slags are of some interest from slag cleaning (by froth flotation), impurity elimination, and environmental points of view. Properties result from both the state of molten slag before solidification and processes taking place during solidification and cooling. In solidification and cooling, copper and sulfur dissolved in molten slag are .precipitating substantially from the silicate phase. Even in water quenching of slag, dissolved copper is pushed out of the solution in the form of finely divided precipitate. Elements present in the raw materials are distributed in a distinct manner between the solidified slag and non-silicate solidification products. Arsenic, antimony, and tin are strongly accumulated in copper precipitate, but not the other metallic constituents common in copper concentrates. Smelting and converting slags differ remarkably on their mineralogical composition and morphology although resulting principally of same chemical processes. Converter slags are more inhomogenous; they often contain solid particles and copper content is .as a rule higher than in matte smelting slags. The final copper content of converter slags was observed to be in a distinct manner dependent on iron oxide - silica ratio. Slag forming, solidification, and precipitation phenomena are discussed on the basis of mineralogical and morphology analysis of smelter slags and laboratory scale experiments.

Jan 1, 2002

Jan 1, 1986

Terramin Australia LimitedÆs Angas Lead and Zinc Mine operates in the unique and picturesque environment of Adelaide Hills, 60 km South East of the Adelaide city centre itself. The mine was granted approval for construction by the South Australian Government in April 2007 and the Process Plant was constructed and commissioned in July 2008. This paper outlines the background to the plant design and the approval process given the close proximity to the local town of Strathalbyn, with a major focus on the commissioning learnings from the Concentrator startup for future reference and a review of the operational performance of the Concentrator throughout the first year of successful production versus design and expectations.

Jan 1, 2009

By Mohammad Nasim

Vertical expansion of existing structures frequently requires foundation retrofitting to enhance the capacity of existing foundations for supporting additional loads. Owing to their small diameter, a variety of suitable drilling methods available for installation, and smaller installation equipment capable of operating under limited headroom conditions, micropiles are often preferred for foundation retrofitting. This paper presents a case history demonstrating application of micropiles to underpin the existing foundation of the Washington D.C. Children?s National Medical Center (CNMC) for its future expansion. Located at 111 Michigan Avenue in northwest Washington, DC, portions of the hospital currently extend five stories above grade and three levels below-grade as parking garages. The hospital intends to expand the surgical wing up to the current build out (five stories) above the remaining portion of the existing parking garage. The original foundations consist of 80-ton Raymond Step-Tapered piles. New loading on the foundations required each Raymond pile to be capable of supporting 150 tons. Results from quick load tests on existing piles indicated that two entire column lines (Column Line A and B) would experience loads beyond their capacity, requiring enhancement of the existing foundation at these locations. The design and construction of the foundation upgrading work was particularly challenging due to various project constraints related to a high groundwater table, micropile installation under limited head room, and ensuring that the parking garage remained fully operational for the entire duration of construction. The paper presents the challenges faced during testing of existing foundations amid a high groundwater table, design developments of underpinning options to support the additional column loads, difficulties and challenges encountered during installation of the micropiles and construction of the micropile pilecaps, and value engineering options developed during various phases of the project. Understanding that micropiles are often a preferred option for foundation retrofitting, the case history is expected to provide a baseline design approach and innovative solutions to typical challenges faced during construction, thereby reducing potential cost overruns during design development and construction of similar future projects.

Jan 1, 2008

By P Rubie, B Morgan, J Russell, C Stewart

The relationship between efficient liner exchange, concentrator availability and concentrator profitability is well documented. Russell Mineral Equipment’s (RME) relationship with OZ Minerals’ Prominent Hill site personnel enabled sound collaboration between the two parties. Both parties worked together to identify the sources of productivity and efficiency loss and developed solutions to reverse them.This paper chronicles the identification of production inefficiencies and the resulting removal of mill relining from the critical path through the materialisation of mill relining optimisation strategies. Furthermore, this paper outlines other recent mill relining optimisation strategies developed by RME and tested at Prominent Hill, to demonstrate and achieve further productivity, efficiency and safety improvements.CITATION:Rubie, P, Russell, J, Morgan, B and Stewart, C, 2017. Mill relining optimisation – a story of collaboration, in Proceedings MetPlant 2017, pp 335–345 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Typically, large volumes of data are collected during geotechnical investigations for mining projects but rarely is this done in a comprehensive manner that enables all aspects of the geotechnical environment to be evaluated. A geotechnical core logging process has been developed to record mechanical and structural properties of the rock mass. The method enables data for a wide range of rock properties and geotechnically significant major structures to be collected including rock strength, joint surface condition, fracture frequency and fracture orientation. The logging method is unique in that sufficient data is collected to enable the independent determination of all the major rock mass classification systems including rock mass rating (RMR), (Bieniawski 1976, 1989; Laubscher, 1990) Norwegian Geotechnical Institute (NGI) tunnelling quality index (Q) (Barton, Lien and Lunde, 1974) and geological strength index (GSI) (Hoek, Kaiser and Bawden, 1995). The logging system has been specifically developed to allow better and more precise appreciation of rock mass and structural conditions across the project area thereby optimising the use and application of the available geotechnical data and improving confidence in the outcomes of geotechnical investigations. This paper describes the core logging process with case examples showing how the logged data can be used for underground and open pit mine design.

Nov 25, 2010

By G. S. Scott, W. J. Huff, G. W. Jones, R. E. Kennedy

"INTRODUCTION This report gives preliminary results of field and laboratory investigations made at the request of the War Production Board relative to causes that have occurred during the last 8 months in acetylene-generat72,r plants in shipyards on the Pacific coast.Six acetylene-generator explosions have occurred in four shipyards. These explosions killed five operators, injured six others, and extensive damage to the plants involved and curtailmnent of vital defense Although the occurrence of acetyiene-generator explosions in other section of the United States is not known, it appears, at least, that if such have occurred, they have caused only minor damage and no loss of lives.The use of acetylene in shipyards on the west coast has expanded tremendously during the past 2 years. These shipbuilding, companies erected aletylene-generatcr equipment, which was soon found to be entirely inadequate to meet the needs of their expanding acetylene requirements for welding, cutting, shrinking, and other purposes, and instances found it necessary to operate their equipment at rates greater than deemed consistent with safe operating practice."

May 1, 1944

By Benjamin Cebrian

Wall control blasting is an expensive and labor intensive operation. Obtaining a good design is a first step that is not enough to ensure desired results. Experience shows that designs are not always well implemented, not only in the contour blast itself, but also in surrounding production blasts that can affect the final pit wall. In this paper techniques and reference indicators are described in order to audit and evaluate if correct implementation of designs have been done.

Jan 1, 2013

Currently raw brown coal is fired in the Latrotx; 'ahcc th,iki~, Lanying with it two major penalties, (a) boiler efficiency of 65 - 70 per cent (in terms of GCV), (b) much higher boiler cost than for black coal. Drying the coal, in energy-efficient, and cost-efficient manner, opens the way to efficiencies of order 88 per cent and enables the lower cost black coal type boilers to be used. With the higher boiler efficiency goes much higher combustion temperatures and the effect of this on radiative heat transfer is a major factor in reducing boiler cost. In a fluidised-bed combustor the temperature is controlled to 800C - 900C. In a pulverised fuel combustor higher temperatures are however achieved and can increase boiler fouling due to the salt content of the coal. This is a problem which needs to be solved. Victoria has the prospect of lifting efficiency from 28/29 per cent to 35 per cent, of reducing carbon dioxide output correspondingly and reducing cost of power stations. So far as gasification is concerned, efficient removal of liquid water from the coal is important to the overall efficiency.

Jan 1, 1992

By Edwards A. B

Occasional, sporadic and small occurrences of lollingite in the Broken Hill lode have been described,(l) mostly in the garnet sandstone in the foot-wall and under-wall of the Broken Hill lode. The lollingite contains appreciable percentages of cobalt and nickel and is regarded as an early mineral in the development of the lode; and, with the incoming of the sulphides, it has suffered considerable replacement by arsenopyrite. During the conversion of iron arsenide into the iron sulpho-arsenide, ilie nickel and most of the cobalt are removed in solution and are inferred to reappear in niccolite and other minerals that have been recorded among the later minerals of the Broken Hill lode. As a result of observations of the officers of ilie Broken Hill South Ltd., an occurrence of cobaltite can now be recorded which has developed by an analogous type of replacement.Cobaltite has previously been recorded from the Australian Broken Hill Consols lode in the vicinity of the rich deposits of silver, though not in contact with them. Cobaltite has been found in the northern extremity of the No. 2 lens of the Broken Hill lode at the 1,480 feet level of the Broken Hill South...

Jan 1, 1944

By H Phillips, A Spaeth, B Belle

There are several well-known, extensively researched and tested methods of suppressing a coalmine methane and coal dust explosion. The choice of method used is dependent on the legislative requirements of each country, which in turn are influenced by mining conditions in that jurisdiction. For example, seam gas content and the dustiness of the coal will combine to create the hazard, while the physical and chemical properties of the seam might influence the possibility of ignition sources such as frictional ignitions. The mining method and layout will also influence the choice of preventative or proactive suppression devices. The decision as to which method is approved and adopted should be based on currently tested and available technology and the latest research outcomes, and should be subjected to a rigorous risk assessment, since a methane explosion propagating into a coal dust explosion cannot be countenanced.Every new technology must undergo stringent tests and these tests must be certified by accredited research facilities or laboratories. Upon approval, an explosion suppression system or the critical components of such a system should be tested in a more realistic environment. This environment can ideally be found in an operating underground mining section for evaluation purposes. Based on the insight gathered in such an environment, a realistic evaluation of the effectiveness of a potential system can be carried out. The explosion suppression system described in this paper has been tested on numerous occasions at accredited test facilities. The technology described in this paper has been used in various applications in underground coalmines and has been adapted to fulfil and exceed the requirements set out for methods currently in use. This paper describes the underground evaluation results of the latest technology in active suppression systems as used on continuous miners was adopted to perform as a roadway explosion barrier.CITATION:Spaeth, A, Belle, B and Phillips, H, 2017. Underground bulk sampling, uniform conditioning and conditional simulation – unrealistic expectations?, in Proceedings Australian Mine Vent Conference 2017, pp 197–202 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Neil H. Brown

Outline ? Cameco - Cigar Lake ? Cigar Lake Mine Development ? MDS #1 ? MDS #1 Improvements ? MDS #2 ? MDS #2 Improvements Pending ? Acknowledgements Mine Development System ? Mining methods tested and developed over the years ? Construction began officially in 2005 ? Water inflow events in 2006 and 2008 ? Successful dewatering and re-entry in 2010 ? Remediation continues ? Production target is mid-2013

Oct 1, 2010

By E. S. Peters, M. J. van Rensburg, M. Le Roux, Q. P. Campbell

"The demand for energy has continued to rise worldwide in line with population growth. The majority of South Africa’s electricity is supplied by coal-fired power stations. The amount of fine coal (-2 mm) generated at coal processing plants has increased, due mainly to mechanized mining methods. Fine coal retains more water, which lowers its heating value.Drying the coal is costly and it is difficult to achieve the required moisture content. Consequently, coal fines are often discarded. An estimated 8% of the total energy value of mined coal is lost1.Fluidized bed technology is often used to dry coal thermally, but this method is expensive and has an adverse environmental impact. The objective of this study was to investigate the removal of moisture from fine coal (<2 mm) in a fluidized bed operated with dry fluidizing air at moderate temperatures as the drying agent. The effects of different air temperatures and relative humidity levels were investigated in a controlled environment. The study further investigated the influence of coal particle size on moisture removal.The drying rate was found to increase with increasing temperature. The relative humidity of the drying air had a more pronounced effect on the drying rate, even at temperatures as low as 25°C.. It became more challenging to remove moisture as the particle size decreased. The gain in calorific value was greater than the energy required to dry the coal samples, showing that a fluidized bed using moderately warm dry air is an energy-efficient drying technology. The energy efficiency of the fluidized bed compared favourably with other thermal drying methods.Paper written on project work carried out in partial fulfilment of Degree in Chemical Engineering(NWU) - Pursuing Masters in Coal Beneficiation"

Jan 1, 2015

In 2007, a total of 7,199 sand and gravel mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 ? Sand and gravel mines were the largest mining sector, comprising 48.4% of all mining operations. ? Sand and gravel mines were found throughout all 50 states and Puerto Rico.

Aug 1, 2009

By F. Mendaña

The characteristics of the igneous and metamorphic bedrock, extra-hard and abrasive, of the Guadarrama Tunnels, a bi-tube project of length 28.4 km without any intermediate attack, are first commented upon. Next, a detailed discussion is given of the most relevant aspects of the performance of the four double shield type TBMs. The experience of this leads to various recommendations to be borne in mind in future designs of TBM having to work in rock of similar characteristics.

Jan 1, 2007

By C. A. Geffen

This report, sponsored by the U. S. Bureau of Mines, presents the results of an examination of the safety of the impactor shaft sinking system in comparison to conventional shaft sinking technology. Detailed study of the impactor system was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the impactor machine and its support systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates measures of both the frequency and the potential consequence of accidents. A safety evaluation of the com¬ponent operations of the impactor shaft sinking system was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that the impactor shaft sinking system is safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by an average of over 35 percent with use of the impactor shaft sinking system. Design change recommendations to further improve the safety of the impactor system include a revised fire suppression system, improved access to and from the operator cabs, reliable noise attenuation measures and improved communication systems. An operational safety manual was also developed for the impactor shaft sinking system.

Jan 1, 1982

By M. L. Free, L. Anthian

Electrochemical, chemical, and image analysis techniques were utilized together with statistical analysis methods to determine the effect of various anode impurities on copper electrorefining performance. Results indicate that arsenic is a beneficial anode impurity. Anode lead and sulfur are shown to decrease electrorefining performance. Specific emphasis is given to the influence of individual elements on current efficiency, slime particle generation, and cell voltage parameters.

Jan 1, 2000

Carlisle: An old friend and good friend, Alan Bateman, is the Silliman Professor of Geology Emeritus at Yale and editor of the Journal of Economic Geology. Now, Alan, let&apos;s start off by telling us something about how you became interested in copper. Bateman: Well, after I left Yale in 1913, I was appointed one of the field members of the Secondary Enrichment Investigation. We spent three years in the field studying all the copper deposits of North America, trying to find out how secondary copper enrichment took place. As part of this investigation, I went up to Kennecott, Alaska, in 1916. After the trip I was asked by the president of the company to become consulting geologist to them. I accepted his offer, and to this day I&apos;m still consulting geologist to the Kennecott Copper Corp. Up at Kennecott, there were both Henry Krumb and my good friend Henry DeWitt Smith, who was general superintendent. He and I had been together at Yale, and I had ushered at his wedding. Interestingly enough, Henry took his bride to Alaska and I took mine there two months later. My assistant was Don McLaughlin, and I think that was his first experience in a mining camp. We published a paper on Kennecott together and cemented a friendship lasting to this day.

Jan 11, 1964