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By K. Sakai, M. Miyaue, T. Aoki, T. Tani, S. Tanaka, N. Kudo

In the planning stage of a tunnel, due to limited technology in the geological survey and the financial restriction, tunnel supports are often designed from unsatisfactory information, and the tunnel construction is started. Therefore, "Information-oriented construction" is carried out in the construction stage, in which the design is rationally verified and modified by observations/measurements. Moreover, the ground conditions ahead of a tunnel face must be predicted for efficient and safe tunnel construction. The authors have examined effective prediction methods to the ground conditions ahead of a tunnel face under construction of mountain tunnels (Aoki et al., 2010) in view of the established method (Schubert et al., 1995). Though the prediction method of Schubert requires the displacement in the direction of tunnel axis, it is difficult to obtain its accurate data by the electronic distance meter. Then, we have proposed a method that uses tilt sensors installed at the tunnel crown near the face to obtain the slight tilting information. To measure inclination of the tunnel crown, this inclinometer was originally developed as a daily control measurement, such that the geological condition and its possible change behind the face could be detected early, and a steady advance and construction safety could be ensured. This paper describes the method of forward prediction mechanism and advantages of this suggested method. It then presents the typical results of a field verification test at a tunnel under construction and an example of evaluation of the ground conditions ahead of the face based on the 3D numerical analysis in three types of condition changes of ground deformation moduli.

Jan 1, 2015

By R. Heikkilä

A large research and development program called RYM PRE (Process Re-Engineering) has been active in Finland since 2010. As a part of the program, a work packet Infra FINBIM is focused on the development of new national process model, specifications and requirements for the whole Finnish Infra Industry. In the Infra FINBIM, total 15 companies and main owners and 3 research organisations are included. The work is further continuing. The main achieved results up today have been the first specifications and requirements of the BIM based total process for infra sector, about 30 different pilot projects for testing of the new design and construction process models producing a lot of results and observations, a new open information transfer format Inframodel3 based on LandXML standard, the achieved acceptance of the Building SMART organization for support of international development, utilization and extension of the format within the whole infra industry, processes, software and other technical equipment. An evaluation of the results and this work will be drawn.

Aug 1, 2013

By H. W. McGerrigle

The St. Lawrence Valley of Quebec lies in an earthquake danger zone, the main centers of which appear to be Murray Bay, Montreal and Quebec City. This paper compares conditions in this "earthquake zone" with those of other, currently more active, earthquake zones of the Earth, deals briefly with the mechanics of earth movements and outlines the means by which earthquakes are re-corded. An account is then given of the earthquakes which have occurred in the Province of Quebec -from that of 1534-35 to the earthquake of 1925. A 50-year frequency cycle is implied. The general conclusion is that the 11robability of future earthquakes should be given more consideration in the construction of buildings in the St. Lawrence Valley region.

Jan 1, 1966

By H De Beer

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Nov 1, 2011

By P. van Zyl, M. Lombaard

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012

By P. Duran

The metallurgical gas handling system at Chagres Smelter, like that of many smelters, can be the limiting constraint to processing more concentrate through the smelter. Mass and energy balances for the metallurgical gas handling system processing off-gases from the flash furnace and Peirce-Smith converters have been used by both operations and process engineering groups to help evaluate different operational scenarios in which the use of the installed capacity could be maximized and/or an operational strategy can be change with the purpose of removing a bottleneck or justifying an investment to relieve a constraint in the gas handling system. The present work describes the development of these process balances that were carried out in Exce®. The results were validated with operational data and, subsequently, some cases of industrial interest were simulated, detecting some conditions that were limiting the operation due to the present installed capacity in the Chagres Smelter.

Jan 1, 2007

By C. G. Anderson

As the global demand for copper and gold steadily increases and the need for environmentally sound processing also grows, successful hydrometallurgical treatment of enargite (Cu3AsS4) concentrates has come to the forefront. This type of concentrate contains considerable arsenic so that successful arsenic fixation, for example as scorodite, is of the essence. This paper outlines the successful application of low temperature and low pressure nitrogen species catalyzed (NSC) hydrometallurgical pressure oxidation of enargite concentrates. The successful stabilization of the arsenic as an iron arsenate compound is discussed. Also, the use of experimental design software is highlighted as a process application and optimization tool.

Jan 1, 2006

By R. M. Berry

A brief outline of refining methods used to (1) upgrade yellowcake to nuclear purity and (2) convert the uranium to the chemical and physical forms required by the fuel fabricators is presented. The uranium hexafluoride (UF6) production facility now under construction at Eldorado, Port Hope, is discussed. Technological improvements in uranium refining are considered.

Jan 1, 1969

By F. -Z. Ji, G. A. Irons, M. Barati, K. Coley

The use of oxygen in electric arc furnace steelmaking is tied to the use of fossil fuels, and slag foaming. The current work examines the kinetics of carbon injection into EAF slags especially the saturation injection rate and available reaction area in the slag foam. Based on individual rate data and experimental gasification rates of carbon in the slags, the available reaction surface area in the gas bubbles was found to be around 1900¬4700 cm2.kg-slg-1 for carbon injection into EAF like slags at appropriate injection rates and steel making temperatures. The ratio of number of bubbles to number of particles is 1 to 17 and the weights of carbon per unit reaction area are 0.001-0.008 gC-cm-2. Using the relationship between active reaction area and x supplied in this study, the gasification rates of carbon in slags can be estimated with gas-slag interfacial reaction rates.

Jan 1, 2004

By H. W. Smith, R. D. Fournier

This paper presents the results of an investigation of a full-scale rod mill. Appropriate numerical techniques are developed for the experimental determination of the parameters of a dynamic mathematical model from steady state data. The results confirm that this full-scale rod mill behaves similarly to laboratory-scale ball mills for which results have previously been obtained. It is noted, however, that although the model presented is adequate for predicting over-all particle size distributions, the size distributions of individual components of a multicomponent ore cannot be predicted.

Jan 1, 1972

While this paper is directed towards the ?Bellambie? type of rope attachment, the principles can be applied to any brand of rope fitting however, it is a only a broad outline and the specific installation and maintenance procedures can be obtained from the attachment supplier. The types of attachment to be discussed are:- ?Thimble Type rope cappel ?Wedge Type cappel ?WRC Rope Clamp ? (Rope Glands) ??Hoist and Balance Rope Sockets In each case, the assembly and stripping (disassembly) plus the basic maintenance procedures is briefly described. A guide for Risk Assessment is also included but because of his familiarity with the installation, the end-user is in the best position to draft the final version.

May 1, 2003

By O. Benavente, M. C. Hernández

Selenium is obtained mainly from copper anode slimes, which is a by-product of the copper electrorefining process. Selenium is present in copper anode slimes as silver and copper selenides. Traditionally, selenium has been obtained by pyrometallurgical processes; however, hydrometallurgy has now been incorporated either full or partial to the conventional process. Some hydrometallurgical processes are been developed and used at laboratory level an industrial scale. This document describes theoretical background and results of characterization and dissolution of selenium from a decopperized anode slimes in an alkaline oxidizing system. The results have indicated that the oxidizing leaching process reaches a practically complete dissolution of selenium (up to 90 %); the undissolved portion is due to the generation of a AgCl around the particle surfaces that delays the progression of the reaction. The results indicated that 90% of selenium extraction can be obtained by dissolution under moderate conditions of pH, temperature and reagent concentration in oxidizing medium. INTRODUCTION Selenium is distributed in the earth's crust in most rocks and soils. Selenium is essential, as it has wide range of applications in the medical and food industries as well as, used in semiconductor, sensors and photochemical devices. Selenium is rarely found in the native state, 90% of selenium is obtained from copper anode slimes, which is a byproduct of the copper electrorefining process (Lu, Chang, Yang, & Xie, 2015; Xiao et al., 2017; Yang et al., 2018). In anode slimes, selenium is present as an intermetallic compound, as Ag-Cu selenides. Currently, selenium is recovered from the anode slimes via hydrometallurgical and pyrometallurgical processes (Lu et al., 2015). The traditional pyrometallurgical method recovers selenium effectively, but faces difficulty as a result of increased energy costs and strict environmental regulations associated with the process (Li, Yang, Jin, Chen, & Tong, 2017). Therefore, hydrometallurgical processes are proposed in oxidizing medium such as nitric acid, alkaline leaching with sodium nitrate, wet chlorination and pressure leaching, amongst others (Hait, Jana, & Sanyal, 2012; Kim & Wang, 2010; Xiao et al., 2017; Yang et al., 2018).

Jan 1, 2019

By C. J. Hodgson

"IntroductionThe Kitsault molybdenum mine is located 600 m above sea level on Lime Creek at the head of the inlet of Alice Arm, 140 km northeast of Prince Rupert, British Columbia (Fig. 1). The area of the mine is characterized by rugged topography and deeply incised creeks which drain into the Portland Canal - Observatory Inlet fjord system. Access is by air service or boat from Prince Rupert, or by secondary road from Terrace.HistoryThe deposit was first staked in 1911, at which time the main feature of interest was a polymetallic vein with values in silver located southeast of the molybdenum deposit (Woodcock and Carter, 1976). Turnbull (1916) was the first to describe the extensive zone of crisscross quartz stringers with Mo~ on the banks of Lime Creek which, although it clearly had the potential to contain a major deposit, was not then believed to be of commercial value.Following sporadic work through the 1920s and early 1930s, the ground lay idle unti11959 when Kennco Explorations (Western) Ltd. commenced a program of systematic diamond drilling on the stockwork-type mineralization adjacent to Lime Creek. In late 1964, Kennco announced the presence of an orebody of 36 million tonnes averaging 0.230Jo Mo~ which was to be put into production at a rate of 5450 tonnes per day under a new subsidiary, British Columbia Molybdenum Ltd., at a forecasted capital cost of $20 million (revised to $30 million).Between January 1968 and April 1972, 10.4 million kg of molybdenum were produced from 9.3 million tonnes of ore, at an average mill recovery of 90%, and with an average mill head grade of 0.206% Mo~. The ore was mined in an open pit with a waste to ore stip ratio of 1.5 to 1. The. operation was terminated in 1972 due to weak molybdenum prices and escalating costs.In May 1973, the deposit was purchased by Climax Molybdenum Corporation of British Columbia, Limited and in 1979 transferred to affiliate Amax of Canada Limited. In early 1979, following completion of detailed feasibility studies, Arnax commenced construction of the 10 900 tonne per day Kitsault mine and mill complex based on a mineable open pit reserve of 95 million tonnes at an average grade of 0.192% Mo~, sufficient for a mine life of 25 years. The original capital cost estimate was $143 million; it subsequently escalated to approximately $200 million."

Jan 1, 1995

By G. A. Moruzi

Two sulphide dust secondacy explosions have occurred in the mines of the SUdbury operations of Falconbridge Ltd. during the past 18 months. 'Ihe main similarity between the occurrences is that they both happened in vertical crater retreat blasthole stopes. A relatively high p:,v.tier factor was noted in both instances. other details are enumerated and examined, as well as some results of tests done by Noranda Research on company ore samples.

May 11, 1988

By Yuki Soma, Tsutomu Ogawa, Jae Hyung Hong, Toshihiro Nagato

The Saganoseki flash furnace was built in 1973. The steel frames of the flash furnace were designed to absorb the expansion of refractories and contain expansion-absorbing materials between their frames and the skin plate. Expansion and deformation resulted in the furnace settler because of the repeated increase and decrease in temperature from more than 30 maintenance shutdowns. Preliminary investigations were conducted to confirm the condition of the settler, and it was found that partial cracks accompanied the expansion in the lower layer of the refractories. As a result, the risk of molten-matte leakage increased. Based on the above investigation, it was decided that the entire settler should be replaced by introducing a spring-displacement structure that was capable of maintaining the furnace integrity over an extended period. The difficult redesign and rebuilding of the Saganoseki flash furnace was accomplished successfully and safely in 76 days from September to December 2017, as planned. Because of various redesigns, the furnace was changed to a flash-smelting furnace that can withstand higher thermal loads based on recent trends of copper concentrate with increased sulfur and reduced copper. The new furnace is operating smoothly at present. INTRODUCTION The flash-smelting furnace of Pan Pacific Copper Co., Ltd. Saganoseki Smelting & Refinary commenced operation in 1973, with an original designed feeding rate of 71 t/h. As a result of facility remodeling and operational improvements, shown in Figure 1, the feeding rate was increased to 215 t/h in recent years. After more than 40 years of operation, the original settler in the melt holding section of the flash furnace underwent significant expansion and deformation.

Jan 1, 2019

By CIM Mineral Resource

On January 9, 2018, the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Council formed the CIM Mineral Resources and Mineral Reserves Committee (CIM MRMR Committee), which is a combination of the previous Standing Committee on Reserve Definitions and the Best Practices Committee. As part of its mandate, the CIM MRMR Committee updates guidelines for use by Industry, which include the Uranium Practice Guidelines. The 2024 CIM Uranium Leading Practice Guidelines were adopted by CIM Council on November 22, 2024, and supersedes the 2003 version. The main principles and guidelines relating to preparation of Mineral Resource and Mineral Reserve (MRMR) estimates are provided in the CIM Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines (MRMR BP Guidelines, as updated from time to time). The MRMR BP Guidelines provide information pertaining to metalliferous and other deposits and many sections are readily applicable to the preparation of MRMR estimates for uranium deposits. However, additional guidance is appropriate for uranium deposits due to the radioactive nature of uranium, and its amenability, in some cases, to in situ recovery (ISR) mining methods.

Nov 1, 2024

By G. P. Gu, B. Fang, R. W. Revie, M. Elboujdaini

Stress-corrosion cracking (SCC) tests were conducted in the near-neutral pH standard solution, NS4, and in an actual soil solution, using four-point bending at high a stress ratio and low frequency conditions very similar to those of operational pipelines. Pitting incubation appeared first and then pitting initiated and grew in both solutions although there were many more pits on the specimen tested in soil purged with 5% CO2 + 95% N2 than in the specimen tested in NS4 solution purged with the same gas. These observations show that samples in soil solution are more susceptible to pitting than those in NS4 solution. When the pit reached a critical size, the increased stress concentration around the pits, resulted in the transition to a crack.

Jan 1, 2005

By Ashu Garg, Anirban Bhattacharya

"Friction stir spot welding of aluminum alloy AA6061-T6 sheets was performed with circular (plunge depths 0.4 and 0.6 mm), square and triangular tool pin (plunge depth 0.4 mm) with constant 0.2 mm shoulder penetration to characterize various zones of weld nugget. It was observed that the depth of the stir zone formed below the tool pin is comparatively similar for different tool pins but wider for circular tool pin. The size of another stir zone formed at the interface of tool pin and a tool shoulder is observed to be larger for triangular and square tool pin due to the higher swept rate. Predicted strain from finite element analysis, calculated strain rate using Zener-Hollomon relationship and experimentally measured grain size distribution indicates severe amount of plastic deformation in-and-around the nugget/spot region. Finer grains in various stir zones were observed than thermo-mechanically and heat affected zones. Grain size (at distribution peaks) in stir zones varied around 2.54 µm to 3.69 µm for different tool pin profiles as compared to base metal grain size of 20 µm. Microhardness results indicate that the welded region is quite softened than base metal and maximum hardness is mostly observed around the thermo-mechanically affected zone.INTRODUCTION Friction stir spot welding (FSSW) is widely used for joining the sheets of materials like aluminum, copper, magnesium, etc. The process begins by plunging a rotating tool (generally having a pin and a shoulder) into the sheets to be welded. Continuous stirring of the tool and downward plunging force generates localized heat due to friction at the tool-sheet interface and plastic deformation of the sheet metal. The material gets softened and the plasticized material adjacent to the tool pin starts flowing due to the action of tool rotation and tool plunge thereby causing intermixing and bonding between the overlapped sheets. The tool stirring also promotes grain refinement in the weld nugget associated with high strain, strain rate and thermal cycle. The formation of new microstructure also affects the mechanical properties and efficiency of FSSW joints. Studies also showed that the tool pin design and tool shoulder feature exerts a noteworthy influence on the material flow and intermixing during the FSSW process (Reilly et al., 2015; Hirasawa et al., 2010). Sarkar et al. (2016) studied the material flow and intermixing during FSSW using tracer material method and reported that the size and width of flow zone increases with tool penetration depth. The influence of tool rotational speed on microstructure and stir zone temperature was investigated during FSSW of dissimilar AA6061-AA5754 alloys (Gerlich et al., 2007). They reported that the average grain size in stir zone of AA6061 weld increases with increase in tool rotational speed. In another work, Gerlich et al. (2008) studied the local melting and tool slippage during FSSW of Al alloys. Tool slippage was investigated by calculating the strain rate using Zener-Hollomon relation. Garg and Bhattacharya (2017a) studied the effect of dwell time, tool pin profiles and tool rotational speed on shear strength, microstructure, temperature and strain distribution during FSSW of AA6061. In another work, Garg and Bhattacharya (2017b) analyzed the effect of different tool pins and pinless tools on the shear strength and microstructure during similar and dissimilar FSSW of AA6061-T6 and pure Cu. Chang et al. (2004) proposed mathematical relationship between the average grain size and Zener-Hollomon parameter during friction stir processing of Mg alloy. Solhjoo (2010) presented a mathematical approach to determine the critical strain as a function of peak strain required for initiation of dynamic recrystallization in austenitic stainless steel. Fratini and Buffa (2005) also proposed the numerical model to determine the grain size during continuous dynamic recrystallization phenomenon."

Jan 1, 2018

By Michael Hopp

The beginning of the electroforming technology dates itself on the beginning of the industrial revolution 1800 to 1820 approximately. Basis was the existence of electricity in order to be able to drive the electro-form-process. With the development of the electroforming, big names of the science-history, like Michael Faraday (1791? 1867), Sir Humphry Davy (1778?1829), Max Schlöter (1878?1946), Werner von Siemens (1816?1892), and many others. Already about 1840, the first monograph originated to electroforming (38). While in the first years the electro-forming most extensive only to the coating of art - or other usefulness-objects was used. At the beginning of the 20th century the formation of objects from pure metals became more and more, later also from alloys to application. One of the first bigger electroforming factory, the ?Württembergische Metallwarenfabrik? was working 1894 in Geislingen / Steige, Germany. In the industrial application, the electroforming-technology is to be imagined away for miscellaneous coatingtasks and the form-body-preparation no longer today (18). A little bit confusing is the german name ?galvano-technology?. It based on the Italian physiologist and naturalist Luigi Galvani (1737 ? 1798). This technically seen is however wrong, right, the name is electroforming. The physical bases were founded mainly by Michael Faraday and Sir Humphry Davy.

Oct 1, 2003

By Karl J. C. Harries

"9.1. INTRODUCTIONIn Chapter 5 of Volume I royalties are dealt with and several topics would appear to be duplicated in this Volume. However, Volume I may be looked upon as a general guide, whereas this Volume is a reference volume. It deals in considerable detail with specific provisions and concepts relating to royalties between private parties. This does not, however, mean that Chapter 5 can be ignored. It should be looked upon as a source of general information concerning royalties between private parties and as a negotiating aid intended to give an overview of various topics. You may well find that in its general approach it will lead you to ask a question which, hopefully, will be dealt with in this Volume .It should be remembered that royalty agreements are agreements with a particular focus, and so the concepts set forth in Chapter 1 apply to them. This chapter addresses a few considerations specific to royalties that will usually form part of an agreement rather than a stand-alone agreement.9.2. FORMAT FOR ROYALTY PROVISIONSIn many of the cases where royalties arise, they are adjunct to, or part of, other arrangements. For example, a royalty may form part or all of the consideration to be given to an owner upon purchase of his property, or it may arise if a joint venturer ceases to contribute to the venture and has his interest converted to a royalty.1 It is with such situations that this section primarily deals; if the royalty is contained in an agreement that is singularly, or primarily, concerned with creating it, then it is just a normal agreement.Commonly, by the time the right to receive the royalty arises, at least some of the other provisions of the agreement have been performed and/or become redundant. For example, in an option agreement the royalty will be a continuing obligation of the optionee, usually arising only after the option has been exercised.2 In a joint venture agreement, a royalty will often arise where the interest of a non-participating venturer has been diluted and converted to a royalty, in which case the recipient will usually become a passive party, entitled only to his royalty, and most of the rights that he enjoyed as an active venturer will cease to be effective."

Jan 1, 2003