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By M. Okido, W. Wei, L. Chai

The kinetics on the growth of Thiobacillus ferrooxidans was studied by use of series piezoelectric quartz crystal ( SPQC ). Arsenic ioninhibits the growth of Thiobacillus ferrooxidans, which is consistent with the previous results by other measuring method. This further demonstrates that the SPQC can monitor the chemical activity of the growth of Thiobacillus ferrooxidans. Cupric ion accelerates the growth of Thiobacillus ferrooxidans. The mechanism was discussed, it was considered that copper promotes the protein enzyme of Thiobacillus ferrooxidans, rustic yanin, to form over the range of cupric ion concentration studied. There action order of cupric ion in accelerating the bacterial growth is 0.067. The growth of Thiobacillus ferrooxidans is dependent on temperature, the apparent reaction activation energy decreases from25.56 kJ / mol to 18.32 kJ / mol because of the addition of 10 mg / L Cu(II) to the bacterial growth solution of pH 2.0 at initial inoculum of 10%.

Jan 1, 2000

By U. Olsson, M. Ramström

"The IREDES1 Special Interest Group (SIG) for drill rigs has been active since its launch during MineExpo 2000 in Las Vegas, Nevada, United States. SIG for drill rigs is responsible for the development of an IREDES drill rig profile, including the exchange of production planning, performance, and quality reporting data between various kinds of drill rigs and the databases used by the operating mine. During 2001, a first draft of the drill rigs profile was jointly prepared by drill rig suppliers, mining companies, and third-party suppliers and reviewed during several SIG meetings. The profile for prototyping projects was released in mid-2002; the first official IREDES release was based on feedback received from these projects.In 2002, LKAB and Atlas Copco decided to carry out an IREDES prototyping project using the Simba L6C production drill rig. The goal was to verify the drill rig profile and identify potential problems prior to the official release. This was done by implementing the IREDES prototype version into LKAB’s production planning and Simba rig control systems. The Simba rig control system was designed to handle drill plan and logging information coming from the mine planning system. In parallel to this, the mine production system was adapted for drill plan export and logging data import in IREDES format.This paper presents the most recent results of the IREDES prototyping project. Results from late 2002 show that the basic architecture of the drill rig profile works and that a common language for data exchange, IREDES, will be a central requirement for future mine automation.As a result of the IREDES prototyping project, the IREDES standard was approved at the IREDES board meeting held at the 2003 CIM Annual Conference and Exhibition. Soon thereafter, IREDES compliant products, including drill rigs and mine production planning systems, were put on the market."

Jan 1, 2005

By K. Grubaugh

Ghana’s physiographic and geologic features are the basis for its long mining history. The Gold Coast colony has been a significant producer of gold. The gold of the Akan forest (Ghana) was a terminus for caravans that plied Saharan trade routes. Now it also produces significant quantities of manganese, bauxite, and diamonds In addition, the country produces kaolinite, silica for glass, salt, and both aggregate and dimensioned stone. Most secondary minerals are consumed locally but some amounts do find international markets. Ghana revised the mining laws and regulations in 1986. These revised laws dramatically increased gold production and improved the country’s economy. The success of these laws spawned imitators in other African states such as Cote d’Ivoire, Mali, and Burkina Faso. Representatives of these countries claim Ghana was their model. Environmental regulations exist but an intensive adversarial atmosphere is lacking. Ghana has also offered the mining industry incentives like accelerated depreciation rates and exemption from import duties on related supplies and capital equipment. The country has also pursued an aggressive policy to restore the nation’s business infrastructure.

Jan 1, 2001

By William Stewart, John Tinkler, Gary B. Hemphill

Of the 345 km long Taiwan High Speed Rail Project, connecting the cities of Taipeiand Kaohsiung, the 23 km alignment on Contract C230 required the construction of5755 m of shallow mined tunnels ranging from 137 m to 1285 m in length. All nine of these tunnels were mined using NATM methodology. On September 6, 2002, a collapse occurred in Tunnel T08 that affected approximately 50 m of tunnel. There was little warning. However, the crew was evacuated approximately 45 minutes prior to failure and thus, no injuries or loss of equipment. This paper will discuss the mining methods, jet grouting ground support, and the instrumentation selected for the rehabilitation and monitoring of the tunnel.

Jan 1, 2005

By James Gibbs

In order to provide an initial approach to the deposits of oil shale, nahcolite, and dawsonite in the central area or the Piceance Creek Basin in northwestern Colorado, the U.S.B.M. and associated contractor personnel drilled and cased a 96-inch ID shaft to a depth of 2,371 feet. The shaft was constructed using ?big hole? drilling techniques and succeeded in giving access to previously inaccessible deposits of the above minerals. This report documents the construction from its beginning in January 1977 to its completion in January 1978. Procedures used and problems encountered are discussed in detail.

Jan 1, 1978

By W. Stumpf

Mill log analyses and complementary hot deformation studies were carried out on the as-cast structure and on a hot rolled structure of the same low carbon steel (SAE 1006) that had been processed according to the direct or hot charge route in a compact strip plant. The main softening mechanisms during hot rolling were found to be complete dynamic recrystallization during each pass above about 1000°C for the as-cast structure with an austenite grain size of 277µm and, secondly, incomplete static recrystallization after each pass with a finer austenite grain size of about 26 µm and tested below 1000°C. A two-stage hot working mechanism has also been found by others on a similar steel also processed by the hot charge route and this may appear to be a characteristic of this type of material. Constitutive constants determined from hot working studies were combined with other constants from the literature and incorporated into a grain size development model that correctly predicts the final ferrite grain size in the hot rolled strip steel. The predicted incomplete static recrystallization during the last three finishing passes in the plant appears to result in some retained strain in the hot rolled austenite as it transforms to ferrite on the run-out table. Analyses with the model predict relatively little sensitivity of the final ferrite grain size to process and product variables such as temperature and strain per pass for the last three passes and also the starting austenite grain size in the slab. Keywords: Low carbon steel, hot rolling of strip steel, rolling mill log analyses, austenite grain size, ferrite grain size, grain size modelling.

Jan 1, 2003

By G. Aggistalis, N. Kazilis, C. Rawlings, N. Rachaniotis, S. Raptopoulos, M. Knights, R. Game

The Egnatia Odos (Odos meaning road) is one of Greece’s largest ever highway construction projects and one of Europe’s most important. The Highway will assist in the connection of the Greek Ionian/Adriatic Coast with Turkey and the Black Sea reviving an historic Roman alignment “Via Egnatia” connecting Rome to Constantinople (now Istanbul). There are 74 twin tunnels (60 bored and 14 cut-and-cover) with lengths ranging from 160 m (175 yd) to 4,600 m (5,031 yd) and 100 m (109 yd) to 270 m (295 yd),respectively. The complex geology and resulting physical geography have had a major influence on both the design and construction of these tunnels. This paper describes the management, design and construction challenges of these numerous tunnels.

Jan 1, 2005

By D. W. Wu, M. T. Haque

A novel impedance probe has been commissioned specifically for capturing fast dynamic information about filtration processes. It provides an attractive alternative to more complex measurement techniques in situations where the slurry system is primarily one-dimensional. The probe can monitor mud-line, slurry densification and drainage. Dynamic variations in cake permeability are obtained by combining dynamic mud-line information obtained with the probe and filtrate rate data derived from a leaf test apparatus. The measurements are re-viewed in relation to micro structural measurements obtained on iron ore filter cakes. The practical significance of these measurements for optimization of the filtration process is discussed.

Jan 1, 2000

By Laszlo Toth

A feeder is used to control the gravity flow of bulk solids from storage areas, like a bin or a stockpile. For this type of application, it is important to select a proper drive that can fulfill all of the demands put on it. High starting torque capacity, variable speed and the ability to handle frequent starts and stops are some of the demands that the drive must be able to meet. The following is a comparison of the most common type of drives used today for feeder applications. When a feeder is started, the breakaway torque may reach as high as200% of the running torque. The accelerating torque usually is set to protect the carrying element of the feeder, like the belt for the belt feeder and the carrying chain of the apron feeder (Fig. 1).

Jan 1, 2003

By R. W. Lowe

1. Reserves are estimated in the Nemo, Sewanee, Wilder, and White Oak beds of Fentress County, Tenn. The Wilder is the only bed being mined commercially and contains the largest known reserves. Eleven lesser known beds are present in the county, but not enough information on them was available for estimating the reserves. 2. Known measured and indicated reserves, based on a minimum bed thickness of 14 inches and on 1,800 tons per acre-foot of coal in place, are estimated at 102 million tons as of January 1, 1955. This total includes 66 million tons in beds 28 inches and more thick.

Jan 1, 1956

By N. Ragoonanthun

Paper written on project work carried out in partial fulfilment of B.Sc. (Mining Engineering) degree This report investigates the optimization of a raiseline in order to open up the ore reserve quicker. The project was carried out at Mponeng Mine (an Anglogold shaft formerly known as Western Deep Levels 1 Shaft and South Mine, in Carletonville). The project was divided into two focus areas namely: ?To design an optimum layout of a raiseline, which includes the scheduling of all activities for the establishment of the infrastructure. Consideration was given to the blasting practice, mining cycle, orepass placement and slusher positioning. Two designs were carried out on the above basis. ?The design of a ledging operation/practice to match the optimized layout of the raiseline. The ledging cycle design involved a thorough investigation into the possible use of drill rigs, Electronic Delay Detonators (EDD) blasting technology, longer drilled holes, Threshold Blasting (THROB),and water jet cleaning.

Jan 1, 2003

By Richard A. Bideaux

With both unit costs per meter and average depth of drilling constantly increasing, there is a strong incentive to maximize the information acquired from drill holes, and then to make this information accessible to the geological staff. The larger the drilling project, the more advantageous computerization of data is over manual methods. The conversion to computer-readable form and the verification of large amounts of drill-hole data can be a substantial data processing task, but once accomplished, the benefits in increased accuracy and speed of interpretation will compensate for the time and effort spent in the work. For an exploration project progressing towards a preliminary feasibility study, about half of both the time and costs for all computer work of the entire feasibility study are devoted to drill-hole data base organization, and maintenance. Once drill-hole results are quantified and verified to be correct, they are immediately accessible and are not subject to further transcription or reinterpretation of errors. To obtain maximum benefits from computer utilization in this area, the drill-hole data base should be set up along with availability of the first data. For some companies, this may initially comprise a large number of purely speculative drill holes on a spacing of perhaps 1 or 2 km. Although few of these drill holes may encounter economic material, thought should be given, at this time, to the variables which will be logged when such material is found. In this way, it should be possible to set up a consistent format into which all future drill-hole information will readily be accommodated. This format may even be carried over into the data base requirements for an operating property.

Jan 1, 1979

By E. Chin

The domination of Bangladesh's mineral industry by natural gas was in for some possibly significant changes. A modest flow of crude oil was struck in a gas development well in the northeastern corner of the country. This was the first commercial flow of crude oil in Bangladesh. All crude oil was being imported, which cost a significant proportion of the nation's foreign exchange earnings. The development of an oilfield producing only a few thousand barrels per day would be a welcome help to the economy. Additional exploration at a 1985 coal discovery in the northwest indicated a considerable reserve of good-quality coal at a depth suitable for mining. If the coal is mined, it would be a boon to the local economy because natural gas was not available in the area.

Jan 1, 1988

By D Thomas

Geochemical data related to AMD for the West Coast and Southland regions have been collated into a relational database and GIS system. The types of information include; rock geochemical data, water chemistry data and aquatic macro-invertebrate abundance data. This information will be combined with eco-toxicology experiments to determine impact thresholds on aquatic ecosystems. Ultimately these datasets will be combined with remediation investigations to produce a Framework to assist decision making related to mine planning, consent and compliance.   Current geochemical research examines the controls on As concentrations downstream of gold mining areas and the variability of AMD from Brunner Coal Measure rocks. Assessment of factors that control the chemistry of Brunner Coal Measure AMD such as mine type, hydrogeology, geology, geochemistry and climate is in progress. Minerals that control the concentration of aluminium downstream of AMD point sources include alunite, jurbanite and various forms of Al(OH)3.

Jan 1, 2005

By A. Z. Toper

This is a sampling of the papers presented at the conference, the proceedings can be bought from the SAIMM An extensive research programme to address the issue of rockburst control has been undertaken over a number of years. This paper discusses the development of preconditioning techniques to control face bursts, for safer mining in seismically hazardous areas. Preconditioning involves regularly setting off carefully tailored blasts in the fractured rock immediately ahead of a mining face, so as to encourage slip on pre-existing fractures, in order not to allow the accumulation of high strain energy density in the rock mass. Two different preconditioning techniques have been developed, namely face-perpendicular preconditioning and face-parallel preconditioning. Both have prevented face bursting in areas to which they have been applied, even though several large seismic events have occurred close to the faces in some areas. In addition, minimal overall damage was observed in the preconditioned panels following these events, compared to similarly exposed unpreconditioned panels. Preconditioning has also provided some protection to the face area from distant events, through the capacity of the preconditioned ground to absorb energy. An improvement in hangingwall stability and productivity has also been noted in preconditioned areas. In order to determine the optimum blast parameters for achieving the most effective preconditioning, an extensive optimization study was carried out for the face-perpendicular preconditioning technique. While optimum values for parameters such as hole length, diameter and spacing were determined, it was ultimately concluded that the differences in results obtained by varying the preconditioning parameters were less significant than the clear positive differences observed when comparing preconditioned areas with non-preconditioned areas.

Jan 1, 2000

By L. P. Lamprecht

Traditionally, South African shaft sinking operations have used electric detonators for the initiation of blastholes. Globally, the trend in shaft sinking is to use the shock tube and detonating cord (STDC) initiation system, with value adding benefits. In pursuing this global trend, Cementation Mining of South Africa in partnership with SMX have ventured the STDC route. This paper explores the work carried out to date, and identifies a number of benefits to be gained by using the system.

Jan 1, 1999

By M. Rantapaa

Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput. Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore. Barrick Goldstrike?s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs.

Jan 1, 2005

By R. Mckinstry, M. Rantapaa, T. Bolles

"Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the open pit and process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput.Better fragmentation and a subsequent increase in mill throughput were achieved through the use of electronic caps for more precision and flexibility, as well as for allowing extremely fast shots; explosives with a higher velocity of detonation (VOD) to provide for improved shock energy; and improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by 6 tph in 2003 due to the improved fragmentation of the hard ore.Barrick Goldstrike’s D2M initiative includes roaster hard ore (BWI>17), as well as autoclave hard ore (BWI>15). Approximately 6 million tons of D2M material were shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs."

Jan 1, 2005

Project Sustainability Assessment - Matching Method to Enterprise Size Sustainable development requires managing natural resources, including minerals, in a way that is conducive to long-term wealth creation and the maintenance of capital (natural, social, human, economic and physical). One aspect of the minerals sustainability discussion focuses on replacing depleted mineral capital with other forms of capital so as to ensure that the contribution of a mineral project is net positive over its life. Another, equally important, aspect focuses on selection of projects and technologies that contribute to the achievement of a variety of sustainability objectives, such as environmental protection, efficient use of resources, water and energy, worker health and safety, and the equitable distribution of risks and benefits within and across generations. Technical feasibility and relative economic performance remain necessary decision criteria for mineral investment decisions, but they are no longer sufficient. Enterprises, regardless of size, are now confronted with the challenge of comparing investment alternatives based on a new, broader set of criteria. The field of integrated sustainability assessment (ISA) emerged in response to this changed social and business environment. ISA is a structured process for examining the economic, social and environmental impacts of a project or technology. The purpose of an assessment can be broad, a strategic review of corporate behavior for example, or quite narrow, input to a specific decision process such as the selection of a piece of equipment. There are numerous methods and analytical tools available to conduct ISAs and selection of the most appropriate for a given situation will depend upon temporal focus (retrospective to prospective), decision context (strategic, tactical or operational), and phase of the assessment process (problem structuring, analysis, resolution, ex post review), among others. Selection also depends upon enterprise size and the attendant availability of financial and human resources. Large multi-national firms often undertake complex, data intensive sustainability assessments, in part because the projects they are involved in are multi-faceted, long term, and require significant financial investments. Small and medium sized enterprises are seldom able to commit the same level of resources to an ISA, and if the projects they undertake are less complicated, a time consuming and detailed assessment may be unnecessary. Regardless of enterprise size, the tangible and reputational benefits of conducting as ISA must exceed the actual monetary cost of doing so. This presentation will provide an overview of available ISA tools, categorising them in terms of their data requirements, methodology, outputs and applicability in various decisions contexts. Distinction will be drawn between situations where reasonable approximations of project impacts can be expected to provide an adequate amount of information and those for which more detailed analysis is essential. Finally, ISA strategies that have been successful and cost effective at different scales of business enterprise will be identified. This is an abstract only. No full paper was prepared for this presentation.

Sep 13, 2010

By Andrew M. Leszcykowski

In 1985 at the request of the Bureau of Land Management, personnel from the U.S. Bureau of Mines examined a 27,680-acre portion of the 30,420-acre King Hill Creek Wilderness Study Area (10-19-2) in order to evaluate the mineral resources. The study area, in southwestern Idaho, is underlain by Tertiary tuffs and basalt. There are no known mining claims or prospects in the study area, and no mineral resources were identified. The Volcano mining district is immediately north, but mines there are in granitic rock which does not crop out in the study area. Oil and gas leases were offered for land in the southern part of the area, but no applications were filed, and the lease offering was withdrawn (1985). INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the King Hill Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986