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By M. Rigaud, N. Zhou, K. Sankaranarayanane, X. Zhou

The effect of amount and type of dispersants on the rheological behaviour of bauxite-based low-cement castables has been studied in detail. The rheological properties: flow resistance and torque viscosity, as measured by a rheometer, are found to be strongly influenced by the amount and type of dispersants. In the present investigation, a mix containing sodium hexametaphosphate, at an optimal level, is observed to be theologically superior at the given experimental conditions.

Jan 1, 2004

By Alan Bauer

IN RECENT PAST YEARS, the mining industry has expanded rapidly and mining engineers have not been generated in sufficient numbers to sustain this growth. Canada has not been alone with this problem, which has resulted in considerable soul-searching as to what the solution might be. Because of the unfavourable economics of running small departments such as mining, metallurgy, ceramic engineering, etc., one approach in some cases has been to put these departments together to form a department of mineral science which now has a broader base structure. Another solution has been the "conversion kit" program which has been conducted both at universities and in industry. At universities, such programs have consisted of converting graduates of other engineering disciplines into mining engineers. In some of the large mining corporations, extensive training programs have been used with the same aim.

Jan 1, 1972

By M. Proulx

"RÉSUMÉ Le diagramme ternaire Al2O3-Sr-Y est un nouvel outil servant à l’exploration de gisements de sulfures massifs volcanogènes (SMV) archéens. Le diagramme permet de discriminer entre les roches volcaniques à minéralisations à zinc dominant (domaine Zn+) et celles à minéralisations à cuivre dominant (domaine Cu+), ainsi que les roches volcaniques ayant subi une chloritisation hydrothermale pouvant aboutir à la formation de chloritites associées aux cheminées d’altération (domaine Cl+). Ces trois domaines délimitent des zones d’influence géochimique ou d’empreintes hydrothermales résiduelles ou fossiles produites par les cellules de convection hydrothermales générées par des magmas. Le diagramme permet aux sociétés d’exploration de déterminer de façon peu coûteuse la fertilité potentielle des roches volcaniques archéennes en ayant recours à leurs bases de données et aux résultats de leurs analyses de terrain, sans aucune manipulation des données. Le diagramme ne s’applique pas aux SMV aurifères.ABSTRACT The tertiary diagram Al2O3-Sr-Y is a new tool to explore Archean volcanogenic massive sulphide (VMS) deposits. The diagram can be used to discriminate between the volcanic rocks where zinc is the dominant mineralization (Zn+ domain) and the rocks where copper is the dominant mineralization (Cu+ domain), as well as the volcanic rocks that were subjected to hydrothermal chloritization that could have led to the formation of chloritites associated with alteration chimneys (Cl+ domain). These three domains define the zones of geochemical influence, or residual or fossil hydrothermal footprints produced by hydrothermal convection cells generated by magmas. Exploration companies can apply the diagram to determine, at low cost, the potential fertility of the Archean volcanic rocks by using their databases and the results of their field analyses, without any data manipulation. The diagram does not apply to gold-bearing VMS deposits."

Jan 1, 2015

By Alex McEachern

MINING LEADS WAY TO PROSPERITY THE year 1937 will stand out in the history of mining and metal products in Canada as one of which we shall always be proud. The combined contribution of these industries played a large part in leading Canada back to prosperous conditions after years of stress and strain that left their mark upon business the world over. A review of general industry shows a marked improvement over recent years. The upward trend continued un-abated most of the year and not a few of the industries had all they could do to supply the demands. A fact that should be appreciated in a year of wheat failure over an extensive area of the Prairie Provinces is the shifting of the basis of Canadian prosperity from agriculture to that of mining and the use of metals. To the great demand for minerals of all kinds, our mines have well responded and many new high levels were reached. This reflects great credit upon the men who direct the activities of the Canadian Mining Industry. Possessed by a spirit which refused to accept defeat in 1931-1932, they began to increase the efficiency of their departments, explored all channels hitherto untried, and won through to a crowning success. Who among them dreamed that their country's extremity would be their Alex. McEachern opportunity, and that through their united efforts our young nation would be enabled to hold that high position she has attained in world affairs?

Jan 1, 1938

By P. Woo, N. Brodusch, R. Gauvin, H. Demers

For developing new technologies, it is important to characterize the microstructure of materials with high spatial resolution at the nanoscale. To achieve high resolution, field emission scanning electron microscopes (FE-SEM) were developed. These microscopes allow working at low accelerating voltage, below 5 kV, to take advantage of the reduction of the interaction volume with accelerating voltage. Furthermore, their higher gun brightness compared to conventional thermo-electronic emitters, allow a probe size at the nanoscale. At low accelerating voltage, the emission volume of backscatter and secondary electron (SE) of the type II signals approach that of SEI signals. However, it is not enough to reach the highest resolution. A magnetic field above the sample improves the spatial resolution by collecting mostly high-resolution signals. In addition, the energy-filtration of the electron signals allows selecting the type of contrast detected: topographic, compositional, or crystallographic. The development of these new technologies permits to extend the imaging capabilities of the SEM towards new nanoscale applications.

Jan 1, 2014

By Dani J. Alldrick, Alastair J. Sinclair, Colin I. Godwin

"The Stewart mining camp has a long history of precious and base metal mining. The camp is abundantly mineralized, with more than 200 widespread, varied, vein prospects, deposits and orebodies. These show wide variations in the mineralogy of ore, gangue and alteration assemblages, and wide variations in textures and structural settings. This report establishes the timing of the different metallogenic epochs and suggests a specific exploration application for systematic leadisotope analyses.Galena lead isotope ratios from a range of mineral occurrences indicate that all these varied deposits formed during two main mineralizing events. Lead isotope data from the Stewart mining camp do not provide absolute ages for the formation of mineral deposits, but the relative distributions of data are consistent with dates determined in other studies. One ore-forming episode occurred in the Early Jurassic and the other in the Middle Eocene. Both metallogenic epochs were brief, regional-scale phenomena. Some deposits from the younger mineralizing episode were emplacedadjacent to or superimposed on the older deposits.Field and laboratory studies show that the two metallogenic epochs are characterized by different base and precious metal suites: Early Jurassic gold-silver-zinc-lead-copper; and Middle Eocene silver-lead-zinc. Therefore, showings of different ages have different base and precious metal potentials and deserve different exploration emphasis. Lead isotope studies provide a reliable, cost-effective method for evaluating the age and commodity potential of small or recently discovered mineral showings and for setting exploration priorities on properties with several varied mineral occurrences. The determination of the age and metal potential of a prospect at an early stage of exploration may govern the urgency, intensity or even the necessity for further exploration work."

Jan 1, 1993

SOME months ago a Committee on Deep-level Mining was appointed [by the Government of the Union of South Africa] to consider the possibility of gold mining being carried on at a depth below 8,500 feet. The Committee consisted of Sir Robert Kotze (Chairman) , Mr. H. S. H. Donald (Government Mining Engineer), and Mr. H. R. Hill. The Committee has now made a report which was tabled in the House of Assembly on March 1st. The Committee reported that the tonnage of ore locked up in the deep level areas of the Central Witwatersrand is enormous, and in the 30 miles between Roodepoort and the East Rand Proprietory Mines has a value of about £200,000,000. The Committee says that, with good ventilation, the present system of wet mining, possibly with some modification and with the aid of refrigeration, may be carried to 10,000 feet, but that greater depths will require the adoption of dry mining. "A vigorous campaign of practical experiment into the possibility of dry mining should be initiated, and the Committee recommends to the Government the appointment of a committee of experts, consisting of representatives of the mining industry, the Mines Department, and the medical profession, with the Government Mining Engineer as chairman. The Committee suggests the provision of £30,000 for the first year for the investigations and experiments contemplated, which could best be carried out by an organization which might be styled 'The Rand Mining Research Institute' and constituted somewhat on the Jines of the South African Institute for Medical Research" . The Committee suggests that this committee of experts should arrange for experiments to be made with dry mining in one of the deepest mines, and investigate ventilation, refrigeration, support of workings, and the physiological problems connected with mining. "We emphasize the necessity of treating this whole question as one of importance and urgency. The investigations should be prosecuted with the utmost vigour and should not be delayed at any time for want of funds or for any other reason. If they are not done thoroughly and quickly, the whole scheme might just as well be left severely alone.

Jan 1, 1945

Partnership with MiHR ? AHRC and MIHR jointly developed Mastering Aboriginal Inclusion for Mining ? Customization specific to mining Mining is unique? ? History of Aboriginal peoples and the land ? Unique community needs ? Effects of Impact Benefit Agreements ? Remoteness of mines ? 1200 Aboriginal communities located w/in 200km of active mines or exploration ? Long term effects of the land

May 1, 2009

By John Oxenford

There are currently two operators producing oil from the surface-mineable portions of Alberta?s oil sands (Syncrude Canada Ltd. and Suncor Inc.) and two other companies are proposing to enter the industry (Albian Sands in 2002 and True North in 2004). Tailings from the two current oil sands plants contain approximately 220 000 tonnes per year of recoverable TiO2 and approximately 80 000 tonnes per year of recoverable zircon. This represents approximately 6% of the world?s TiO 2 consumption and approximately 9% of the world?s zircon production. With the commissioning of plants by Albian Sands and True North, and the announced expansion of plants by Syncrude and Suncor, it is expected that these tonnages could quadruple in the next ten years. All of these operators have at least 50 years of reserves even at these expanded production rates. The occurrence of heavy minerals in Alberta?s oil sands has long been known and is well documented in the literature. There have been a number of attempts to produce market-grade products from this resource and the results of this work have been quite mixed. Typically, researchers have used the normal mineral dressing techniques of the industry and have found the mineral assemblage does not respond to these techniques all that well. This has led to the widelyheld suspicion that there must be some difficult metallurgical problems associated with this resource. There are three main problem areas that have created difficulties for previous researchers: 1) The bitumen coating on the sand grains; 2) Secondary mineralization such as pyrite, siderite and calcite 3) A high proportion of aluminosilicates (approximately 25%) that have the same gravity, electrostatic and magnetic properties as other minerals in the heavy mineral suite. Recent work by Lakefield Research shows that these problems can be largely overcome with some novel approaches. The bitumen can be removed by washing with a solvent in the presence of a demulsifier. The pyrite can be removed by flotation. And the titanium and zircon minerals can be separated by selective flotation followed by conventional electrostatic and magnetic separation.

May 1, 2001

By Y. Héroux, A. Chagnon, M. M. Savard

"Résumé - Le gite de Pb-Zn de Gays River s'accompagne d'anomalies des propriétés de la matière organique (MO) et des assemblages de minéraux d'argile (AMA). L'association entre la minéralisation, la distribution de la réflectance de la MO et des AMA suggère que ces traceurs peuvent servir à I ‘exploration des sulfures de métaux de base dans cette région.A I ‘emplacement du gîte, la réflectance varie considérablement (0,8% à 1,88%), pouvant même afficher une baisse avec I ‘enfouissement, ce qui est interprète comme une altération chimique de la MO. Les valeurs les plus élevées s'accompagnent localement de quelques textures en mosaïque et délimitent une anomalie thermique au centre sud de la région. Parmi les minéraux des argiles identifies, I ‘illite et la chlorite sont terrigènes alors que la smectite, la kaolinite et la corrensite sont authigènes et, à l' instar de I ‘altération de la MO, résultent des nouveaux équilibres chimiques créés suite à la précipitation des sulfures.Abstract - The Gays River Pb-Zn ore deposit is associated with anomalies defmed from the characters of the organic matter (OM) and from the clay minerals assemblages. The relationships between these anomalies and the mineralization at the mine suggest that these parameters can be used as new guides for the exploration for base-metal sulfides in this area.The vitrinite reflectance (RJ shows a wide range of values (0.8% to 1.88%) and exhibits an anomalous suppressive effect with depth of burial at the mine site, suggesting a chemical alteration of the OM. The highest R"" values are associated with mosaic textures and outline a therrnal anomaly at the south-center of the studied area. Among the identified clay minerals, illite and chlorite are terrigenous, whereas smectite, kaolinite and corrensite are authigenous and, like the alteration of the OM, are due to the new chemical equilibria resulting from the precipitation of the sulfides."

Jan 1, 1994

By M. Cossette, V. H. Tran

"How can the durability of asphalt pavement be doubled without increasing highway budgets? Asphalt containing asbestos can provide the desired performance with additional costs being made up by longer life. The addition of a low percentage of asbestos to an asphalt mix permits a higher asphalt content without any consequent loss in stability. It is mainly the higher asphalt content that provides improved performance and durability, although the fibrous reinforcement plays a key role in preventing the propagation of micro-fissures. As well, several international studies show that, thanks to the latest production techniques, no environmental hazards need be incurred.RésuméComment doubler la durée des chaussées d'asphalte sans augmenter les budgets de voirie? L’asphalte contenant de l'amiante peut offrir les performances souhaitées et l'augmentation des couts initiaux peut être rapidement compensée par une durée prolongée. L’addition d'une faible teneur en amiante courte il l'enrobe de bitume permet des teneurs en bitume plus élevées sans subir une perte de stabilité en conséquence. C'est principalement la teneur accrue en bitume qui assure un améliorations propriétés physiques et une augmentation des performances mécaniques, ainsi qu'on prolongement de la durée. Cependant, le renforcement fibreux joue un rôle clef en prévenant la propagation éventuelles micro-fissures. Les nouvelles techniques évitent tous risques environnementaux"

Jan 1, 1991

By Shahé Shnorhokian

Numerical modeling is increasingly being used as a tool to examine complex geomechanical issues related to rockmass behaviour and stability of underground openings. The in-situ stress regime and the evolution of mining-induced stresses during the life of an operation, taking into account the planned stope sequence, are topics that can only be handled through the use of a realistic and calibrated numerical model. This paper presents a case study of a deep underground Canadian mine in northern Ontario. A FLAC3D model was constructed and calibrated based on in-situ stress measurements. In the first stage, the evolution of stress regime was studied and compared with the occurrence of rockburst events during a period of three years. The locations of clusters were examined and compared to the mining sequence during that period. In the second stage, stresses within a diminishing ore pillar were examined based on the planned stope sequence and compared to levels deemed acceptable to the mine. Based on the results, an alternative sequence was arrived at to reduce stress accumulation in the pillar, or induce it to occur at a further distance from a brittle dyke in the vicinity of the orebody.

Aug 1, 2013

By Stewart A. Ferguson

Location.-The property consists of eight claims (P-12339 to 12343, 12403 to 12405) in Robb township, adjoining Jamieson township on the west. A mocor road extends twenty-two miles northwest from Timmins to the mine. Acknowledgments.- The field work was done in 1940 and 1943, while the writer was employed by the Ontario Department of Mines. The Metals Reserve Company has made available information regarding the property through Messrs. W. R, Dunbar, of Hollinger Consolidated Gold Mines, and W. C. Ringsleben, of the Metals Control Board, Department of Munitions and Supply.

Jan 1, 1945

By M. J. Michaud, M. J. Lavigne

"Abstract - North American Palladium Ltd. operates its Lac des Iles open pit palladium mine 85 km north of the city of Thunder Bay, Ontario. The Roby Zone deposit occurs within the mafic/ultramafic Lac des Iles Intrusive Complex (LDI-IC), which was created by multiple pulses of magma of varying composition within several closely spaced chambers. Chaotic lithological distribution, the presence of magmatic breccias, and the rarity of rhythmic layering suggest a dynamic intrusive environment with disruptive magma pulses. As of December 31, 2001, measured and indicated resources for the 950 m long by 815 m wide Roby Zone deposit totalled 159 Mt grading 1.55 g/t Pd, 0.17 g/t Pt, 0.12 g/t Au, 0.05% Cu, and 0.05% Ni at a palladium cut-off grade of 0.7 g/t. The Roby Zone contains an additional 73 Mt of inferred resources at similar grades.The Roby Zone is dominated by varitextured gabbro containing pipes and pods of breccia, and large blocks (~60 m across) of varying lithology. Mineralization at Lac des Iles occurs as: (1) a PGEand base metal-rich magmatic matrix of breccia (breccia ore); (2) mineralized dikes or sills (gabbronorite in North Roby ore); (3) lower-grade mineralization in varitextured units that are host to the distinctive breccia ore and envelope the North Roby ore; and (4) high-grade mineralization associated with strong silicate alteration exemplified by high-grade ore.The close spatial association of the mineralized breccias with both varitextured units and silicate alteration leads to an interpretation that the energetic magma that created breccia was charged with a dissolved fluid, and that this deuteric fluid exsolved at high temperatures to migrate through crystal mush, enhancing crystallization along its pathways, resulting in variable grain size. This transformation occurred at high temperature and produced sulfide-poor, varitextured gabbro-hosted mineralization exemplified by some of the mineralization in the North Roby Zone, and also found throughout the Roby Zone. The association of hydrous silicate alteration with mineralization can be explained by continuing fluid migration during cooling and continued metal transport. Résumé - North American Palladium Ltd. opère la mine à ciel ouvert de Lac des Iles située à 85 km au nord de Thunder Bay, Ontario. Le gisement Roby Zone est encaissé dans le complexe mafique/ultramafique de Lac des Iles (LDI-IC), lequel représente une intrusion polyphasée créée par plusieurs pulses magmatiques de différente composition à l’intérieur de chambres magmatiques fermés. La distribution chaotique des lithologies, la présence de brèches magmatiques, et la quasi-absence de litage rythmique suggèrent un environnement magmatique dynamique perturbé par l’introduction de nouveau magma. Au 31 décembre 2001, les ressources mesurées et indiquées s’élevaient à 159 millions de tonnes titrant 1,55 g/t Pd, 0,17 g/t Pt, 0,12 g/t Au, 0,05% Cu, et 0,05% Ni, pour une teneur de coupure de 0,7 g/t Pd. De plus, la Roby Zone contient 73 millions de tonnes de ressources inférées à une teneur similaire.La Roby Zone est principalement encaissée dans un gabbro de texture hétérogène (varitextured) caractérisé par des cheminées et des lentilles de brèches et des énormes blocs (environ 60 m de diamètre) de plusieurs lithologies. Au Lac des Iles, la minéralisation en EGP et en métaux de base se retrouve dans la matrice magmatique de brèches (breccia ore), dans des dykes ou des sills minéralisés (gabbronorite dans la zone North Roby ore), comme minerai de basse teneur encaissant le minerai de brèche (breccia ore) et enveloppant la zone North Roby. Du minerai de haute teneur est également associé avec une forte altération en silicates dans la zone high-grade ore.L’étroite association spatiale entre les brèches minéralisées et les unités de texture variée (varitextured) et l’altération en silicate suggère que le magma énergique qui a causé la bréchification était chargé de fluides. Ces fluides deutérique"

Jan 1, 2001

By Alan L. Sangster

Auriferous, bedding-parallel veins occur in zones of carbonaceous, argillaceous and sulfidic turbidites in the Lower to Middle Cambrian sandy flysch of the Goldenville Formation. The 0348 values for vein and wall-rock arsenopyrite and pyrrhotite, and for regional pyrite and pyrrhotite, are highly positive. The values are similar to those from Cambro-Ordovician sediment-hosted deposits of other types, and display trends that increase upward in the stratigraphic sequence. The similarity in composition of vein and wallrock sulfides indicates a seawater-sulfate sourCe for sulfur, derived from the enclosing rocks at the time of vein formation. The upward increase in ?34S values is consistent with closed system sulfate reduction in the anoxic portion of a stratified water-colurnn. Published ? 13C and ? 18() values for Meguma Group vein carbonates are unlike those of other gold-vein carbonates, but are similar to those of diagenetic-metamorphic carbonates from the Meguma Group and elsewhere. These data indicate that the source for the vein-related sulfides and carbonates may be the host strata; possibly the arsenic and gold were derived from the same source.

Jan 1, 1992

By Q. Jia, M. Rigaud, F. Ye, X. Zhong

In this work, the rheological behavior of ultra-low cement alumina-based castables with addition of flake graphite and extruded graphite pellets has been investigated. Emphasis has been laid on the influence of the type and amount of carbon additions and the results are compared with corresponding alumina castable samples without any carbon addition. It is found that alumina-based castables with extruded graphite pellets have good rheological behavior and flowability with lower water demand (< 6.3%), and no segregation during the shearing of castable.

Jan 1, 2004

By Lawrence Devon Smith

What is a Failed Project? For mining projects, some key indicators of a ?failed? project are: ? Cost is more than it should be (particularly capital) ? Schedule ? It takes longer to build than expected ? It takes longer to ramp-up than expected ? It does not do what it is supposed to do ? Poor performance; output, product specifications; ? Low revenue ? High costs ? No one is happy about it: Management, Shareholders, Bankers ? Does a project fail if it does not meet expectations that were unrealistic and unattainable? ? Caution: Failure may not become evident until years later

May 1, 2010

By A. L. MacAllister

"Keymet Mine lies on the Elmtree River 4 miles west of Petit Rocher and about 18 miles northwest of Bathurst, Gloucester County, New Brunswick. A good gravel road runs through the property.The deposit was discovered in 1880 when a vein 7 to 8 feet wide was re-ported. In 1883 the first shaft was sunk as part of an exploration program which was carried out sporadically until 1897, when the company dissolved. Activity on the property was intermittent until 1946 when the property was again staked and during the next year diamond drilling intersected the vein in several places. In December 1949 Coulee Lead and Zinc Mining Company optioned the property and held it until its sale to Keymet Mines Limited in June 1952. By July of the same year work had begun on a three-compartment shaft.Early development work was concentrated on the 150, 300 and 450 foot levels but the shaft has since been sunk to I,228 feet to allow for eight levels at intervals of 150 feet. Little lateral work has been done to date below the 600-foot level.The first mill constructed to treat the ore was to go into production in the spring of 1954, but was destroyed by fire. A second mill, having a capacity of 200 to 300 tons a day, was officially opened October 25th, 1954. Present shipments are zinc and copper-lead-silver concentrates.The rocks of the area are shale, conglomerate, limestone, and quartzite with minor interbedded volcanic rocks, all probably of Silurian age. Small plugs of Devonian acidic intrusions occur 3 miles east and about 5 miles northwest of the mine. Minor dykes of both acidic and basic rocks occur on the mine property. In many of the fine-grained sedimentary rocks the more brittle laminre have been brecciated and give the rock the appearance of an argillaceous conglomerate."

Jan 1, 1949

By J. Zollinger, J. R. Kennedy, E. Bouzy, B. Rouat, D. Daloz

"Ni-based superalloys have been replaced in the last low pressure stage of jet turbines for aircraft by titanium aluminides. In order to improve the properties of these Ti-Al alloys and extend their usage deeper into aircraft engines grain refinement by inoculation has been investigated. Borides are the most common inoculants for Ti-Al alloys, however they form brittle particles which are detrimental to the final properties of the alloy. Inoculants manufactured from a Ti-Al alloy with refractory metal additions were proposed to alleviate the issues arising from inoculation with brittle particles. An alloy was chosen which had less than 10% lattice mismatch with the alloy of interest (Ti-46Al) to maximize efficiency. Initial experimentation showed a decrease in as-cast grain size by a factor of 2 between the inoculated and non-inoculated samples along with an absence of the brittle particles found with boron inoculations. Investigations into the interaction between the inoculants and the melt were also carried out to better understand the inoculant size distribution and efficiency upon solidification.INTRODUCTIONTitanium aluminum alloys are an interesting material for aerospace applications. Their high temperature oxidation resistance and high specific strength make them particularly promising (Kim & Dimiduk, 1991). Recently, titanium aluminides have replaced nickel based superalloys in the last low pressure stage of the GEnx turbine engine. In order to increase their usefulness in turbines their properties must be improved for high temperature (>800oC) applications. Grain refinement is one method to improve the properties of a material, however current methods of grain refinement of Ti-Al alloys by inoculation have significant drawbacks. A new method of inoculating Ti-Al alloys by using Ti-Al alloys with small refractory metal additions (Nb, Ta) has been developed to avoid the drawbacks of current methods while still being effective grain refiners."

Jan 1, 2016

By Candido Bariáin

A new vapochromic material of formula [Au2Ag2(C6F5)4(bipy)2]n (bipy = 2,2´ bipyridine) has been developed and used for the detection of some volatile organic compounds as acetone either in vapour or in water solution. The material is presented in the form of powders which colour changes with acetone vapours turning from bright yellow in the absence of vapour to white in the presence of vapour. By using the sol-gel technique, the powder ? dispersed in tetraethyl orthosilicate- was easily deposited on optical fibres. In order to study experimentally the behaviour of this material for construction practical optical fibre sensors, a sol-gel material doped with the vapochromic material is deposited onto an extreme of a monomode fibre connected to a coupler. The behaviour of the material was studied for different wavelengths and concentrations of acetone vapours and acetone/water solutions. Changes up to 4dB in the reflected optical power were detected. Optical fibre sensors have many advantages over conventional ones, such as electromagnetic interference immunity, passivity behaviour, possibility of using multiplexation techniques, low weigh and little size, etc. Actually, there is an increasing interest in developing optical fibre sensor for vapour detection in the chemical industry and in fact many sensor had been developed [1]. Some are based on the deposition of a sol-gel-based material either over the core of an optical fibre [1] or onto the thinner zone of a biconically tapered optical fibre [2]. Others are based on Fabry-Perot interferometers [3]. Also there are sensors based on the reflection of the light on films, on the fluorescence of dye-doped polymer cladding in fibre, on colorimetric reagents in the core of a silica fibre or on surface plasmon [4]. The possible materials for the construction of such sensor should be colorimetric reagents able to change the colour or refractive index in the presence of same organic vapours. There are not many metallic complexes with these properties, although same interesting examples have been reported in the chemistry of palladium and platinum as [Pt(p-R-C6H4NC)4][Pd(CN)4] described by Nagel [5] and Mann [6], which reported the construction of some LEDs. We recently reported the preparation of a novel vapochromic material (Fig 1) [7] which can be used for the construction of optical fibre tapered environmental sensors [8,9] of vapour organic compounds (VOC´s). Also we reported other nickel and palladium derivatives which present this type of behaviour [10]

Oct 1, 2003