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By Frederick J. Browne

Water, water everywhere, but not a drop (fit) to drink! Trite, but how often only too true? What is there met with in mining which, under various circumstances, may be said to be the most sought-for and highly-prized and also the most objectionable and most feared? Water! What visions that combination of five letters brings to all thoughtful minds? Up to near the end of the eighteenth century water was thought lo be an element but was then discovered to be the result of the combustion of two volumes of hydrogen with one volume of oxygen, and water so produced is chemically pure. Pure water is a clear and colourless liquid when seen under ordinary conditions, but appears bluish when seen through a long tube, and this same bluish tint may be observed in many lakes, especially those of glacial origin. A story often told describes a prospector in the desert who, failing to find water to replenish his canteen, suffers torture and death under fearful circumstances. Then again we may recall the flooding of mines, where water poured in so quickly that there was no opportunity of saving the unfortunate workmen. Instances might be multiplied without number showing that either the lack or excess of this essential fluid has taken heavy toll of human life. In all branches of mining and associated industries water must be dealt with to a larger extent, from an economic point of view, than any other substance, and very often the purity of the water is a matter of considerable importance.

Jan 1, 1925

By C. S. Crocker

The Centennial orebody was discovered and named in 1970, Manitoba's centennial year. It is relatively small, about 2 million tons. Strike length varies from 400 to 600 feet and widths from 10 to 60 feet; dip is 75 degrees. Low grade and metal prices demanded low-cost mining, and the mine was developed for conventional sublevel stoping. As the ore lay entirely under a large lake, ground movement had to be avoided and the stopes were to be filled hydraulically. Late in 1973, vertical crater retreat mining was introduced at Inco Limited, Sudbury, to recover pillars between filled stopes. It proved satisfactory and the results were publicized by CIL, who developed the technique. The method seemed to offer some advantages and one stope at Centennial Mine was selected to be mined by VCR while production was maintained from blasthole stopes. The trial stope was safe and showed lower development costs, reduced drilling time, a favourable powder factor and good fragmentation. VCR mining is now an accepted method at HBM&S Co., Ltd., and its use is being extended.

Jan 1, 1979

By S. D. F. Rocha1, L. Katsarou, G. P. Demopoulos

"Crystalline scorodite (FeAsO4·2H2O) has been pointed out as the most stable compound to immobilize arsenic for disposal due to its good stability performance according to EPA’s TCLP test. However, in anaerobic conditions, arsenic releasing is increased to undesired levels due to scorodite reductive break down, in eh <100 mV at 5.5< pH <7 which causes contamination of groundwater. In this work, the concept of encapsulation by controlled deposition of mineral coatings immune to pH or redox potential variations is presented. Aluminum and calcium phosphates were evaluated as coatings and the release of arsenic from scorodite previously coated with phosphates was substantially decreased when compared to the VALUES (obtained from crude scorodite, both in oxic and anoxic conditions. INTRODUCTIONThe widely acknowledged hazardous properties of arsenic as a soil and natural water contaminant and its adverse health effects when present in drinking water have led to very strict environmental regulations (Mandal & Suzuki, 2002) aiming at the drastic reduction of the presence of arsenic in the effluents of the mining and metallurgical industries.In Canada, the Metal Mining Effluent Regulations (Government of Canada, 2002) dictate that the maximum monthly mean concentration in tailings for arsenic must be lower than 0.5 mg/L. At the same time the new Environmental Protection Agency’s (EPA) standard for drinking water foresees concentrations of arsenic less than 0.01 mg/L, which means that the leachability limit for the industrial waste is set at 1 mg/L arsenic (EPA, 1994; Le Berre et. al, 2007). One of the preoccupations of the mining and metallurgical industries is directed to the elimination of arsenic presence in all its effluents, especially since arsenic is commonly found in many ores mainly in the form of oxides and sulphides. After processing of arsenic-containing ores and concentrates, arsenic can be present either in solid residues and tailings, liquid effluents or in flue dusts. Several of these forms of arsenic waste materials are soluble and therefore may cause the contamination of ground water, if disposed of without further treatment."

Jan 1, 2012

By J. Trojacek

A large-scale development in exploration and production of uranium ores in the Czech Republic was done in the 2nd half of the 20th century. Many uranium deposits were discovered in the territory of the Czech Republic. Over a period of 50 years approximately, 110 000 tons of uranium in concentrate were produced. Different mining methods were developed and used. One of the most considerable deposits in the Czech Republic is the site Hamr na Jezere ? Straz pod Ralskem where both mining methods ? the underground mining and the acidic in-situ leaching ? were used. The extensive production of uranium led to widespread environmental impacts and contamination of groundwaters. Over the period of ?chemical? leaching of uranium (ca. 32 years), a total of more than 4 million tons of sulphuric acid and other chemicals have been injected into the ground. Most of the products (approximately 99.5 %) of the acids reactions with the rocks are located in the Cenomanian aquifer. The contamination of Cenomanian aquifer covers an area larger than 27 km2. The influenced volume of groundwater is more than 380 million m3. The total amount of dissolved SO4 2- is about 3.6 million tons. Approximately 0.5 % of the contamination is located in the Turonian aquifer. After 1990, a large-scale environmental program was established and the Czech government decided to liquidate the ISL Mine and start the remediation in 1996. The remediation consists of contaminated groundwater pumping, removing of the contaminants and discharging or reinjection of treated water. The objectives of the remedial activities are the followings : to restore the aquifer to a condition guaranteeing continuing usability of Turonian water of Northern Bohemia Cretaceous, to decommission boreholes and surface installations and to incorporate the surface of leaching fields into the ecosystems taking into account regional systems of ecological stability and urban plans. Nowadays four main remedial technological installations for reaching of these aims are used - the ?Station for Acid Solutions Liquidation No. One?, the ?Mother liquor reprocessing? station, the ?Neutralization and Decontamination Station NDS 6? and the ?Neutralization and Decontamination Station NDS 10?. Total capacity of this complex is sufficient to reach the target values of remedial parameters in 2037. The remediation action consists of: pumping of residual solution to the surface, separating uranium from the solution and reprocessing contaminants into commercially usable or ecologically storable products. It is expected that the amount of withdrawn contaminants will vary from 80 000 to 120 000 tons per year. Total costs of all remediation activities are expected to be in excess of 1.5 billion EUR.

Aug 1, 2013

By F. Charette

Instrumentation has been developed that can monitor the strain applied to a D-Bolt up to 7.5% elongation. The technology far exceeds the limit for foil resistance strain gauges. In the laboratory the instrumentation has provided insight into the fundamental behaviour of the D-Bolt following yield. Currently the instrumentation is undergoing field trials at a number of Canadian Mines. Discussion on field results is provided with regards to significance, reliability and temperature effects.

Aug 1, 2013

By K. Raht

LEAD poisoning is perhaps the oldest and, until recent years, the most misunderstood of all industrial diseases. Hippocrates appears to have recognized a relationship in the colic experienced by a patient who worked with metals, and the ancient literature is filled with references to the colics and &apos;dry bellyaches&apos;. The colic and other sequalæ following drinking of lead-bearing waters and, particularly, wines has excited possibly more comment in the older medical literature than any other ætological factor. It was not until1656, when Stockhusen definitely connected the colic of the workmen with the fumes given off in the process, that the true danger to those working with lead was recognized. Unfortunately, something over 200 years elapsed before industry took any note of Stockhusen&apos;s discovery; it remained for Legge and Goodly and investigators of the early 1900&apos;s to forcibly educate their profession and industry to the manner in which lead gained entrance to the body. The work of Legge and Goodly was published in 1912 and the clearness with which these investigators presented the scientific data which they had accumulated will mark this volume as perhaps the first and most important contribution to our modern knowledge of the subject. It also ushered in a period when, in the short space of thirty years, lead poisoning has been reduced from one of the most baffiing and widespread o industrial diseases to one which can be anticipated and controlled. The next great contribution came in 1926 with the publication of the work of the Harvard group. Here, for the first time, was the physiological behaviour of lead laid bare, and it is to the discoveries of these authors that we owe our modern treatment of lead poisoning.

Jan 1, 1941

Cominco began investigations about ten years ago relative to noise abatement in underground operations. As a result of intensive research, this study has advanced so that the practice now has wide application. Automotive mufflers are used on vane-type blasthole diamond drills. Exhaust hoses are attached to longhole percussion drills. Hand-held drills, such as airlegs and stopers, are equipped with mufflers which are either part of the drill, as received from the manufacturer, or are light rubber de-vices developed, fabricated and installed by Cominco. Ear defenders are in general use. The paper reviews details of practices employed, and assesses the success achieved. Noise is generally associated with some of the basic equipment used in mining. About ten years ago, in order to improve on this situation. The Consolidated Mining and Smelting Company of Canada Limited began investigations relative to noise abatement in its underground operations. As a result of intensive research, this study has advanced to the point

Jan 1, 1964

By P. Favreau

This paper describes the progress accomplished at the Noranda Technology Centre in the field of three-dimensional computer-aided underground blast design. Traditional methods of laying out underground blasts are reviewed, and the new computer-aided approach is described. Time savings achieved through the use of BLASTCAD can be advantageously used to better engineer blasts, using models and blast vibration analysis. Future work involving the attachment of blast models directly to the system is also addressed.

Feb 1, 1993

By K. Iturralde

The topic of this article is the automation and robotization in refurbishment processes of industrial buildings. The need to mold these production spaces is quite universal. Particularly in the regions with a high industrial development and with a lack of buildable land, there is a need to convert this kind of spaces into an improved production system. The latest developments can be a useful tool for achieving a more efficient way of reforming this type of construction. On the one hand we have the digital or computerized 3D Laser Scanning (Computer Aided Measurement) that allows an accurate 3D modeling of the entire building. On the other hand, the project management using BIM (Building Information Modeling) could provide an easy design of each of the elements of the refurbishment. Finally, through the production of construction elements using robotics as jig or for CNC (Computer Numerical Control) we achieve a neat production of each element. How can be all those technologies applied in the refurbishment or expansion of industrial buildings? The research takes a first approach and analyzes industrial buildings that can be called generic or not specialized. To narrow the field of refurbishment, three major factors are defined. The first is to minimize the bill of the energy consumption of the buildings. This could be done either insulating the envelope, reducing the waste-volume to be conditioned climatically or creating facilities for energy production. The second is that the refurbishment or expansion of industrial buildings should try not to interfere on the production process that takes place in the building. In other words, the assembly of the elements in the construction site should be quick and easy, causing the least of disturbance at the workplace. Finally, the research makes an approach towards a robot integrated industrial or productive building .

Aug 1, 2013

By Tim Gitzel

Thank you for your introduction, and thank you to the CIM for inviting me to make a presentation to you today. This is my first opportunity to report to you on the status of the Canadian uranium industry and I am pleased to tell you that the industry is in good shape, and well positioned for the future. As you will no doubt be aware, Saskatchewan benefits from the world?s largest known highgrade deposits of uranium as well as from a high level of provincial, public and northern community support. It is within this unique combination of geology and community that our industry operates. Uranium markets have been extremely competitive for a number of years for several reasons. First, deregulation in the nuclear electric power industry has tended to encourage fuel buyers to use up their large inventories built up at a time when rapidly increasing demand was anticipated. Second, alternate sources from surplus commercial stocks, military materials and reprocessed fuel have presented a major additional source of uranium supply. Today, these secondary supplies are meeting about half of uranium reactor feed requirements. Canada (that is, Saskatchewan) is the world?s largest ?natural? uranium producer with about a third of the global production. Saskatchewan?s mines produced more than 30 million pounds of yellowcake in 2002. Despite low prices, steady demand for uranium will continue. In fact, an increase in world uranium production in 2002 helped feed a more than 3 per cent increase in reactor fuel demand. Low cost production is important for surviving low market prices, but investments are based on longer-term strategies rather than simply responding to market cycles. Cost is not the only issue. In these times of increasing regulatory and public scrutiny we must continue to earn the trust of our stakeholders by adopting the highest standards and staying on the leading edge of technical, social and environmental developments. Managing these issues is as important as traditional concerns of ore grade and cost of production. The last two decades of the 20th century saw the Province of Saskatchewan rise to prominence as the leader in uranium production from facilities, which were at the time deemed world class. These facilities are now either at - or nearing - the end of their production years. We are now bringing on new facilities that will position Saskatchewan to remain the world leader in uranium production for many years to come.

May 1, 2003

By F. Bélanger, P. Fournier

"The Detour Lake Mine is located in northeastern, Ontario, approximately 300 kilometres northeast of Timmins and 185 kilometres by road northeast of Cochrane. The mill processes a free milling gold ore using both gravity circuit and leaching with a state-of-the-art carbon-in-pulp circuit. The grinding circuit is a conventional SABC circuit with a tonnage of 60,000 mtpd at 95 microns with the addition of pre-crushing upstream of the SAG mill. This paper will highlight the impact of a pre-detox thickener on the cyanide consumption in a gold leach/CIP circuit. While the pre-detox thickener was built with the intention to reduce the cyanide consumption, the opposite effect was observed when the thickener was put temporarily offline. It will show how the re-circulation of a dilute stream of cyanide into the grinding circuit, increases the overall slurry temperature and by the same effect, increases the dissolved copper concentration in the leaching circuit which subsequently increases the cyanide consumption.INTRODUCTION The processing plant is using a conventional gravity, cyanidation and carbon-in-pulp processing facility currently operating at approximately 60,000 mtpd. The comminution process is based on two parallel SABC lines, each fed from an individual reclaim tunnel. Cyclone overflow from the two ball mill circuits is directed to the pre-leach thickener. The thickener underflow is distributed to two (4) parallel leach trains of 5 tanks each, each leach train providing 29 hours of leaching retention time. After leaching, the gold in solution is recovered in a carrousel CIP circuit consisting of two (2) parallel leach trains. Tails from each CIP circuit are combined and sent to a pre-detox thickener to recover as much cyanide solution as is economically practical before being diluted and fed to a cyanide destruction system. The detoxified tailings are sent to the Tailing Management Area (TMA) for settling and retention. The excess water from the TMA is reclaimed and recycled back to the processing plant. The pre-detox thickener is designed to thicken the leach tails slurry to 64% solids with the overflow being recycled to the grinding circuit. It is estimated that the pre-detox thickener will recover 60% of the cyanide in the CIP discharge solution. It is also designed to reduce the SO2 consumption by diluting the thickener U/F to 50% solid using the tailing pond reclaim water which has very little cyanide content."

Jan 1, 2019

By C. Samuelsson, G. Carlsson

Characterization of dust from Boliden Mineral AB’s copper-plant in Sweden was carried out using chemical analysis, X-ray diffraction analysis, energy dispersive analysis and wave length analysis using electron microprobe equipment. Dust from four different locations was characterized: the electrostatic precipitator (ESP) after the roasting furnace; the ESP after the copper smelting furnace; from the copper converter ventilation bag house filter; and from the bag house filter collecting dust from the settling furnace and tap gas ventilation. The results showed that the dust is composed of small solid and/or liquid particles from the furnace reactor which have been transported with the process gas to the dust collecting devices. This portion of the dust is mechanically formed. It also contains compounds that have been vaporized in the process and then condensed from the process gas at lower temperature, chemically formed dust. The proportion of mechanical and chemical dust varies with the process generating the dust.

Jan 1, 2001

By Stewart W. Daniel

"Increasing labour costs, the trend to larger mills, the processing of lower grade ores and a diminishing sup-ply of well-trained and experienced mill operators contribute to the necessity of automating a grinding circuit. With sophisticated process control techniques, supervision of the mill line is reduced to an occasional inspection by the shift supervisor. Process operating decisions and/or adjustments are quickly and accurately performed by the electronic devices to be described. When the variables in the grinding circuit are stabilized using the sensors and controllers as discussed, the over-all grinding circuit is maintained at its optimum grinding load level, with ample protection against under-and overloading."

Jan 1, 1967

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

"The main purpose of geometallurgy is to develop a model to predict the variability in the mineral processing performance within the ore body. Geometallurgical tests used for developing such a model need to be fast, practical and inexpensive and include as an input data relevant and measureable geological parameters like elemental grades, mineral grades and grain size. Important in each geometallurgical program is to define the number of samples needed to be sent for geometallurgical testing to enable reliable metallurgical forecast. This is, however, a complicated question that does not have a generic answer.To study the question on sampling a simulation environment was built including a synthetic ore body and sampling & assaying module. A synthetic Kiruna type iron oxide - apatite deposit was established based on case studies of Malmberget ore. The synthetic ore body includes alike variability in rock types, modal mineralogy, chemical composition, density and mineral textures as its real life counterpart. The synthetic ore body was virtually sampled with different sampling densities for a Davis tube testing, a geometallurgical test characterising response in magnetic separation. Based on the test results a forecast for the processing of the whole ore body was created. The forecasted parameters included concentrate tonnages, iron recovery and concentrate quality in terms of iron, phosphorous and silica contents.The study shows that the number of samples required for forecasting different geometallurgical parameters varies. Reliable estimates on iron recovery and concentrate mass pull can be made with about 5-10 representative samples by geometallurgical ore type. However, when the concentrate quality in terms of impurities needs to be forecasted, the sample number is more than 20 times higher. This is due to variation in mineral liberation and shows the importance of developing techniques to collect qualitative information on mineral and ore textures in geometallurgy."

Jan 1, 2016

By J. A. du Plessis, C. Dorfling

Selenium, tellurium and other precious metals (OPMs, namely Rh, Ru and Ir) dissolve in the final leaching stage of base metal refineries. Se and Te are typically removed from the copper sulphate leach solution by precipitation with sulphurous acid. Recovery of dissolved OPMs is desirable because it will reduce OPM inventory and losses. Thiourea is an effective OPM precipitation reagent, but yields insufficient Te removal. Copper is known to enhance Te precipitation when using sulphurous acid as precipitation reagent. The primary objective of this project was to evaluate whether simultaneous precipitation of Se, Te and OPMs using thiourea with metallic copper as precipitation reagents is possible. Batch precipitation tests were performed to evaluate the effect of temperature (50 – 70°C), thiourea addition (160 – 430% excess) and copper addition (2 – 8 g/L) on Se, Te and OPM precipitation. Increasing the temperature from 50°C to 70°C resulted in an average increase of 55.6 percentage points for Se precipitation and 13.5 – 23.5 percentage points for OPM precipitation. The copper addition did not have a significant impact on the precipitation behaviour. Increasing the thiourea addition increased the precipitation of Se and Te, especially when the copper addition was low; Rh and Ru precipitation also increased with up to 10 and 12 percentage points, respectively. Despite these observations, the precipitation of Se was significantly faster when no thiourea was added. It is not currently clear why thiourea appears to inhibit the Se precipitation by reaction with metallic copper. In general, Te precipitation was low (less than 30%) at the conditions investigated. Simultaneous precipitation of Se, Te and OPMs at temperatures below 80°C does not appear to be a viable option; a multiple stage operation for sequential removal of Se and Te with copper followed by OPM precipitation with thiourea would be required.

Jan 1, 2016

By Yong Kang, Bingyuan Yan, Dandan Zheng, Xiaochuan Wang, Dengfeng Su, Dongyang Li

"According to the characteristics of rock mass and the directional cutting technology of water jet, a new idea of light shock controlled blasting with water jet slotting was put forward. Based on the fracture mechanics theory and the stress wave theory, the mechanism of damping with water jet slotting was analyzed. On the basis of the above, the evolution law of the pressure wave and displacement field during the blasting were simulated by FEM software ANSYS/LS-DYNA. The result shows that: the oriented slot plays a good role in orientation during the blasting, and makes the energy generated by gas released by the explosives gather at the tip of the oriented slot, which makes it easier for the main crack to expand along the oriented slot and indirectly reduce the stress effect on the protected object. Meanwhile, the energy of the seismic wave is reduced while transmitting through damping slot. Finally, compared with the normal blasting with damping ditch, the maximum acceleration is reduced by 15.62%, the maximum velocity is reduced by 52.99%, and the maximum displacement is reduced by 68.32%. INTRODUCTIONIn recent years, with increasing demand for energy and space, an increasing number of underground projects have been under construction. Drilling-blasting method, as a traditional main method for rock excavation, is still an indispensable means in the engineering construction. As is known, blasting vibration will cause the deformation and unstable of the existing building structures, so how to reduce the influence on the existing building structures caused by the blasting vibration has become the focus. Traditional shock absorption measures mainly include three kinds: the first one is pre-splitting blasting, the second measure is to change the parameter of explosive filling, and the last one is to excavate damping ditch between the protected object and blastholes. However, engineering practices show that: the protected rock may be damaged in the process of pre-splitting crack construction by blasting, the second measure is difficult in operating, and the third measure is troubled by large work quantity (Song Guangming, 1999; Lou Jianwu, 2004; Lou Jianwu, 2005; Li Xibing et al., 2008)."

Jan 1, 2015

By D. B. Apel

As depths to the ore bodies keep increasing around the globe, the problem how to deal with the increasing temperature of undisturbed rock mass becomes very important. In extreme cases the rock temperature at the bottom of the mine could raise up to 80 °C. In deep mines, geothermal heat is considered as the primary heat load contributor, which accounts for 50?90% of the total heat load depending on different geological conditions. Thus the geothermal heat control in underground mines is the most important and demanding issue to ensure a suitable working environment. In this study, expanded perlite aggregate (EPA) was incorporated as a lightweight substitute for sand. Five mixtures were prepared using 0, 25, 50, 75 and 100% replacement ratios of sand by EPA. These, mixtures were tested in the laboratory for both the insulating and strength properties of the developed shotcrete. The goal of this research was not only to develop shotcrete which would exhibit good insulating properties but also which would exhibit strength properties similar to the regular shotcrete. This paper not only reports the results of the laboratory tests but also discusses the output of numerical model which was performed to evaluate the benefits of using the insulating shotcrete in reducing the cooling costs at hot underground mines.

Aug 1, 2013

By P. Favreau

"This paper describes the progress accomplished at the Noranda Technology Centre in the field of three-dimensional computer-aided underground blast design. Traditional methods of laying out underground blasts are reviewed, and the new computer-aided approach is described. Time savings achieved through the use of BLASTCAD can be advantageously used to better engineer blasts, using models and blast vibration analysis. Future work involving the attachment of blast models directly to the system is also addressed.IntroductionThe Noranda Technology Centre&apos;s (NTC) Environment and Mining Laboratory, in cooperation with the mining operations of the Noranda Group, is committed to the development and implementation of new technologies in the field of mineral extraction . Within the frame of its research program, the Blasting Technology Program is developing computer "" tools"" designed to assist the blasting engineer or technician. These computer "" tools"" are regrouped under a global software system called BLASTCAD.The BLASTCAD project started in 1990 at NTC. At that time computer programs designed to calculate and model various blasting parameters had been accumulated. These programs cam e from different sources and were mutually incompatible. Furthermore, they were developed as research programs with tittle effort spent on user interface. These programs are very useful, but are highly specialized, need large input files and can be quite tedious to use as ""standalone"" packages .Therefore, the situation being faced was one where all these programs were available at the Noranda Technology Centre, but not a t the operations. The two following options were then considered: 1. continue to run all the models and programs at the Noranda Technology Centre, and present results through reports to the mines, or2. regroup all the different programs under a single one that would make them share the same data base and be transported to the user. This second option is the one that was adopted; the result is BLASTCAD."

Jan 1, 1993

By W. Evans, C. E. Ells

Nuclear power reactors using zirconium alloy pressure tubes generate electricity in several countries. Such reactors are particularly important in Ontario, where CANDUs* generate about 30% of the total electricity produced in the Province. Starting with the commitment of NPD-2 in 1956, the pressure tubes of the first five CANDU reactors were made of coldworked Zircaloy-Z, an alloy of Zr and Sn. This alloy was developed by the US Navy, but the decision to use it in a cold-worked condition was based on AECL work. In 1958, the USSR published information on a new alloy, Zr-2.5 wt% Nb. The Nb promotes stabilization of the (3-phase in the material, thus presenting opportunities of exploiting metallurgically strong pressure tubes analogous to the heat-treatable cx-{3 titanium alloys. After construction of two reactors using Zr-2.5 wt% Nb in a quenched and aged condition, an extensive development program on cold-worked Zr-2.5 wt% Nb pressure tubes resulted in them becoming the reference tubes for all CANDU reactors committed since 1966. Anticipating the future needs of the domestic and export markets, AECL have pressure tubes of Zr-3.3 wt% Sn-0.8 wt% Nb-0.8 wt% Mo (Excel) in an advanced state of development. These tubes will be used in an annealed condition; our projections show that they will have improved dimensional stability over the lifetime of the reactors. These improvements result from experimental programs leading to an understanding of the relationship between microstructures and fabrication variables and effects of the environment during service in nuclear reactors.

Jan 1, 1981