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By W. Abdellah

Underground mine developments, such as haulage drifts and cross cuts, play a vital role in providing access to ore extraction areas for mine production. The stability of mine developments is thus of crucial importance during the life of a mine plan. Many Canadian mines use longhole mining methods or one of its variants. These methods require access to the orebody through mine developments such as haulage drifts and cross cuts on multiple levels. This paper examines the stability of mine development access intersections with respect to the planned mining sequence. A case study, the #1 Shear East orebody at Vale?s Garson Mine in Sudbury, Ontario, is presented. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) was created for a development intersection situated 1.5 km below ground surface. The stability, or performance of the intersection, is evaluated in terms of the strength-to-stress ratio. The ratio threshold is set at 1.4 for temporary openings. Unsatisfactory performance is defined as a strength-to-stress ratio less than this threshold value. The performance of the intersection stability is evaluated at various modelled mining stages and the probabilistic method of analysis is then invoked to study the probability of unsatisfactory performance of the intersection. The results are presented and categorized with respect to probability, instability, and mining stage.

Aug 1, 2013

By S. Dallaire

With the attainment of high temperatures it becomes possible to process any kind of material (particularly ceramics) in their liquid state. In the plasma spraying process, the material to be sprayed is rapidly heated until it is molten and is propelled by high velocity gases onto a surface where it adheres, to give protective coatings for a wide range of applications. The method could be considered as one of the most versatile and rapid to build up thick deposits (of plastics, metals, ceramics, cermets) and also free-standing artifacts for particular requirements without resorting to lengthy forming and sintering studies. Although plasma spraying is at the production stage in industry, advanced processes have also been developed for economically producing a wide range of new materials. This paper illustrates the benefits of the process and evaluates the challenges it represents.

Jan 1, 1987

By E. Gaucher, M. St-Amant

"Among the electromagnetic surveys performed by SOQUEM in the last three years, a certain number of the more instructive cases have been chosen to illustrate the theory of electromagnetism by field examples of: (a) The depth penetration of the TURAM as compared to the SLINGRAM (Ronka) method. (b) The limitations of the TURAM as compared to the SLINGRAM method when a conductor dips the wrong way, or when it is small in size. (c) The expression of a shallow-dipping conductor in a SLINGRAM survey. (d) The effect on the SLINGRAM survey of deep ditches or reef structures.(e) A comparison between the CRONE and the SLING-RAM method in the Abitibi clay belt, by means of field and model studies, indicating a usually better signal-to-noise ratio for the SLINGRAM method. From the above and from other experiments, different electromagnetic methods are now being used by SOQUEM, depending on field conditions."

Jan 1, 1970

By E. Krause

The oxidation of Fe(II) with S(IV) and oxygen can be used advantageously in leaching systems requiring both Fe(III) and sulfuric acid; e.g., heap leaching of sulfide-containing ores or concentrates. The oxidation of Fe(II) with SO2/air is several orders of magnitude faster than with air alone; rates of up to ?20 g/L'h were observed at 25°C. The reaction proceeds via an intermediate orange-red mixed-valence Fe(II)/Fe(III) sulfite complex, which is present at an essentially constant concentration throughout most of the oxidation process. The oxidation rate of Fe(II) is approximated by the formula -d[Fe(II)]/dt = k [S(IV)] [02]0'3. The concentration of the mixed-valence complex, and thus the iron oxidation rate, decreases with increasing acidity. Certain impurities, such as SCN- and thiourea, negatively affect the rate. The oxidation reaction 2Fe2 + SO2 + 02 4 2Fe3+ + S042- is accompanied by the side reaction H20 + SO2 + 1/202 4 H2SO4. The side reaction becomes particularly important at low temperatures and whenever the oxygen mass transfer is insufficient with respect to the rate of addition of S(IV). Thus, effective oxygen mass transfer is essential for achieving high oxidation rates with minimal acid formation. The activation energy was estimated as 141 kJ/mol over the temperature range 10-35°C.

Jan 1, 2006

By K. S. Coley, G. A. Irons, T. Kaneyasu

"It is very important to reveal the lime dissolution mechanism in steelmaking slag, to promote its dissolution without calcium fluoride, which is now almost forbidden for use in most industrialized countries. In this research, the purpose was focused on the development of an experimental method to measure the mutual diffusivity of Ca2+ under the condition of lime dissolution into slag. By forming diffusion couples using a ""vacuum slag aspirating technique"", the method was established. The following mutual diffusivities of Ca2+, in CaO-SiO2-FeO slag systems, imitating oxygen steelmaking slag, were determined using this method:4.1*10-10 m2/s at 1400°C for 27wt.%CaO-53wt.%SiO2-20wt.%FeO slag,4.3* 10-10 m2/s and at 1400°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag, and 1.3*10-10 m2/s at 1250°C for 20wt.%CaO-40wt.%SiO2-40wt.%FeO slag.It was also verified that, if the basicity and ferrite content of the bulk slag are low, then a calcium silicate film forms on the lime surface, and drastically deters the lime dissolution."

Jan 1, 2004

By R. C. A. Thurston

Introduction A mechanical spring has been .defined by Wahl ( 1) as 'an elastic body whose ?primary function is? to deflect or distort under load, and which recovers its original shape when released after being distorted'. Most material bodies are elastic to some extent ? and will deform under load, but they are seldom regarded as springs since this is not their primary function. The principal applications of springs are the absorption of energy and the mitigation of shock, the support cf moving masses or the isolation of vibration, and the provision or measurement of definite loads or torques. A large number of spring types have been developed to serve these purposes and to meet the different operational requirements; they range from the large semi-elliptic leaf suspension spring to the delicate watch hairspring. The springs of most importance in machine design, however, are the helical round-wire compression or tension types. They are made in a wide variety of sizes and are used in tremendous quantities, mainly because of their low cost, their compactness, and their relatively high efficiency. Their field of application is as broad as that of machine design itself, but the bulk of production is almost certainly for suspension systems of vehicles such as automobiles, freight and passenger cars, and mine cars, and it is with the last of these applications that this paper is primarily concerned.

Jan 1, 1951

By X. -P. Zhang, L. N. Y. Wong

Shale gas exploitation initiated in North America has rapidly extended worldwide. Hydraulic fracturing is an emerging field technique for stimulating the gas reservoir. The study of cracking processes, particularly crack coalescence, is vital for a successful hydraulic fracturing to enhance the gas exploitation. Experimental studies have observed that the size effects of the constituent particles are significant on the cracking behavior of the rock specimens. To further investigate the size effects, the bonded-particle model (BPM), which is based on the discrete element method (DEM), is adopted in the present research. In flaw-containing specimens, by varying the crack resolution (?= a/2R), which is the ratio of half flaw length (a) to particle size (2R), the size effects on cracking behavior under compressive loading are studied. By keeping the flaw length constant, the particle size is varied independently in the BPM analysis. Decreasing the crack resolution increases the first crack initiation stress, but it has no obvious effects on the uniaxial compressive strength. The trajectories of the first cracks and secondary cracks hence generated have a higher resolution and are well-defined in those specimens possessing a higher crack resolution. On the contrary, in lower crack resolution specimens, the macroscopic first cracks appear to be wider and less continuous. These findings from numerical simulation clearly demonstrate particle size effects on cracking behavior. Special attention should be paid to these effects in future numerical study using the bonded particle model.

Jan 1, 2015

By H. Itou

A mechanism of scorodite formation at ambient pressure was investigated using transmission electron microscopy (TEM). Several types of iron arsenate were obtained from Fe/As solutions (Fe/As = 1.0 and 1.5) at pH values of 1.0, 1.25 and 1.5 at 95°C. Amorphous FeAsO4.xH2O was precipitated from solutions having a higher mole ratio of Fe/As at pH l.5, even after 9 hours. A few micron sized particles were observed by SEM, but these proved to be agglomerates of 10-50 nm amorphous FeAsarxH2O particles when observed by TEM. This means that supersaturation of the solution causes the acceleration of nucleation of iron arsenate hydrate. Crystalline scorodite was obtained from a solution in which the Fe/As mole ratio was unity, at pH l.0 and pH 1.5, after 3 hours. Almond-type crystalline scorodite particles were observed by TEM and most of them showed high crystallinity. The addition of scorodite seed material enhanced the crystallization. Amorphous FeAsO4.xH2O, however, was observed at the surface of the seeds during the early stages of precipitation. It is postulated that crystalline scorodite is not directly precipitated even on crystalline scorodite seeds, but requires a certain time to crystallize on the seed material.

Jan 1, 2006

By B. Dyck, L. Verhelst

"Colloidal silica in Key Lake’s Solvent Extraction (SX) feed solutions has presented an operational problem for the mill throughout its history. The colloidal silica stabilizes aqueous continuous emulsions, resulting in elevated solvent losses and operational downtime. Through the years, many attempts have been made to solve this problem, but no viable solutions were found. By revisiting an idea dating back to the 1979 feasibility study and re-evaluating it under current operating conditions, a practical solution was achieved. This paper discusses Key Lake’s history around colloidal silica removal, starting with coagulation using a polyethylene oxide polymer (PEO), and ending with coagulation using a polyethylene glycol (PEG) polymer. The results of a mill trial using POLYSIL® RM1250 introduced at doses up to 300 ppm into the counter current decantation (CCD) circuit to clarify SX feed solutions are discussed with a focus on the benefits to SX.INTRODUCTION Colloidal silica has historically been a significant operational problem in the Key Lake mill. Silica originates from clays in the ore as well as concrete backfill intermixed with the ore resulting from the mining method used at Key Lake’s ore source, the McArthur River mine. The silica is dissolved as silicic acid into solution in the mill’s sulphuric acid leaching circuit. Once in solution, silicic acid polymerizes (Hearn, Smethurst, & Boskovic, 2016) forming a fine suspension of stable colloidal particles. These silica colloids are unaffected by flocculants and sand filtration reporting to the pregnant leach solution (PLS) as a fine turbidity in solution. Silica concentrations typically ranged from 700 to 1200 mg/L Si in the PLS fed to SX. Throughout Key Lake’s history, silica interactions in the Solvent Extraction (SX) process have made SX a mill bottleneck and a source of significant reagent costs."

Jan 1, 2018

By J. M. Bowen, P. Wemyss

"Gold losses to natural carbonaceous matter during cyanide leaching have been investigated for over a century. The variation in the severity of the problem from one ore to another has led to a range of different processes being implemented at different mine sites. Most commercial options utilise one or more of the following processes: roasting, carbon pre-flotation, organic blinding, CIL, chlorine passivation, pressure oxidation, biological passivation, elevated temperature CIL, RIL and thiosulfate. This paper provides a background to identify the most appropriate process or combination of processes for a particular ore. It also presents information on how these processes may be implemented, drawing on information in the literature and from current or recent applications at operations such as the following: Stawell, Kumtor, Penjom, Twin Creeks, Macraes Flat, Kittilä, Fosterville, Inata, Carlin, Goldstrike, and Jerritt Canyon. Various process options have been dismissed, or deemed unsuccessful due to limited knowledge available on the strengths and weaknesses of the different options and their implementation. The authors have collectively been involved in flowsheet development and project implementation in four commercial plants that have treated preg-robbing ores.INTRODUCTION Cyanide processing has been the mainstay of gold recovery for well over a century. It is generally a very effective process with over 90% recovery on free milling ores, but complex and refractory ores may only give 0–50% recovery with conventional processing (La Brooy et al., 1994). People have written about gold losses to natural carbonaceous matter during cyanidation for over a century e.g. Feldtmann, (1915). The earliest reports related to African operations, but the issue has since been reported in Canada, North and South America, Australia, Russia and China. The phenomenon is usually referred to as ‘preg-robbing’ dating from the times before the use of granular activated carbon for gold recovery, when gold was lost from the pregnant solution before it could be separated from the leach solids and recovered by cementation. Many excellent reviews have been published e.g. Dunn et al. (2013), summarising the options considered and where they have been applied commercially."

Jan 1, 2017

By S. D. Anitha Kumari, T. G. Sitharam

"The huge urbanisation of the world cities have invariably resulted in enormous requirements of development in transport and other facilities. As the surface space available for the construction of these infrastructural facilities is found to be inadequate, underground space is widely used recently for this purpose. However, to understand the behaviour of these underground structures through experiments under various loading conditions is not practically feasible. Hence numerical methods have widely been used to model these structures and predict their behaviour. The underground structures generally rest on soil or rock. Depending upon the properties of the material surrounding the tunnel, the deformation pattern and the stress contours vary. If the tunnels are placed on soft ground at a shallow depth, the presence of existing structures will add to the stresses and strains developed. In the case of densely populated cities, tunnelling operation may result in huge damages if the settlements are not within the desirable limits. This may in turn lead to the collapse of the tunnel along with adjoining structures. So the determination of stress levels associated with the yield of wall due to excavation is very important and necessary supports and reinforcement should be provided. Numerical simulations using discrete element method (DEM) and finite element method (FEM) have been done to understand the stress variation around single and twin tunnels. Studies are also done to quantify the improvement of stability on the introduction of lining around the tunnels in a weak cemented soil mass like sandstone.INTRODUCTIONMost of the life line facilities which include pipelines for electricity, water, communication, sewage, gas, roads, metro, utility tunnels etc in modern urban areas are underground structures. Infrastructure development is crucial for any city and sustainable development urges for underground constructions. Accordingly, there is already a great demand for tunnels to be constructed in difficult and crowded urban settings. This results in the fact that a large number of risk factors are associated with tunnels in these densely populated urban areas. These constraints pose threats to tunnel construction and also demands for minimal disturbance to the public and to the surrounding utilities. One of the most important factor to be considered while designing an underground structure is its stability with respect to the surrounding medium and adjoining existing structures. In this study, a comprehensive presentation of the numerical modeling of single and twin tunnels adopting two different methods is presented."

Jan 1, 2015

By D. L. Griffith

THE realization by metallurgists of the important effect that traces of impurity may have upon the properties of a metal, and their steady demand for purer and still purer metals, have made the special cools for 'trace' analysis of increasing value. In the United States at least, spectrographic analysis is becoming the standard method for determining the impurities in zinc die-casting alloys. The Hudson Bay Mining and Smelting Company, as a producer of virtually pure zinc, uses the spectrograph to control the purity of its products, and-as the electrolytic method is employed here-to control both the impurities in the electrolyte and those 'trace' elements, which, while they do not contaminate the zinc, have a great effect on the plating efficiency. The general plan of the laboratory is shown in Figure l; the housing for air purification, which is on the roof, is indicated by broken lines. One of the chief factors affecting the layout was the easy way in which a spectrographic assay can be spoiled by contamination. To minimize the quantity of dust tracked in, the laboratory was made separate from the general research laboratories, and an office was placed between the two. This arrangement has its drawback because of the traffic through the office, but it has effectively cut down dust. For similar reasons, the available space was subdivided into a number of small rooms, and the air currents in the laboratory were so arranged that dust would be carried where it would do least harm. Air is drawn in at the roof over a 50-kilowatt bank of Calrod heaters, through Annis air filters, by a No. 4 Sirocco fan. Most of it is forced into the spectrograph room, but some goes to the office and darkroom. The air flow is from the spectrograph room, through the plate-measuring room, into the chemical laboratory, where it is exhausted by a No. 1% Sirocco fan on the fume hood. Air can also re-circulate from the plate-measuring room back to the heater. The arrangement is such that the air in the laboratory is maintained at higher pressure than the outside air; consequently, no dirt enters through cracks about the windows and doors. A thermo-regulator holds the temperature constant within one or two degrees; only on the hottest days in summer does the temperature rise enough to affect the focus of the instrument.

Jan 1, 1940

By D. S. Rogers

"Throughout the history of mining at the Dome, gold has been found in a number of different rock types and in association with a number of different structural settings. Diamond drilling plays an important role in the evaluation of the stratigraphic and structural features which control ore deposition. The main function of diamond drilling is to locate favourable areas of mineralization.To date, over 20,000 diamond drill holes have been drilled from combined surface and underground programs. Needless to say, a great many significant intersections, carrying a wide range of gold values, have resulted from the total of over 756 miles of drill cores which these programs have produced.However, the term ""significant"" takes on new meaning in light of the experience of diamond drilling in a number of ore-type situations at the Dome Mine. Drilling through individual ore veins, such as the Fuchsite Vein or the Quartz-Tourmaline Vein, often intersect the vein structure; however, assays from the veins frequently fail to yield any ore grades. Similarly, drill cores through stringer-type occurrences such as dacite or conglomerate, when assayed, fail to indicate the true size or grade of the orebody ultimately mined.IntroductionOver the years, those who explore for gold and those who have the slightly less fickle task of actually mining gold have shared a common dilemma. That dilemma lies in the failure to relate the results of diamond drill information to a positive ore situation, or ultimately to reconcile ""diamond drill indicated ore"" to actual ore reserve tonnages.Drawing on the knowledge of more than 72 years of mining history at the Dome operation in the famous Porcupine Camp, this paper will review a number of drift and stope situations in which the grades of the ore material extracted will be compared with the anticipated grade of that same drift or zone as calculated solely on the basis of diamond drill assays."

Jan 1, 1982

By A. Mortazavi, H. Nasab

"The storage of petroleum products on surface is associated with difficulties and limitations. Accordingly, a viable alternative is to excavate underground space in rock and provide a safe way for oil storage. Soft rocks such as salt domes provide good conditions from environmental and operational points of view. The potential for high-volume storage and low permeability are encouraging aspects for oil storage in salt domes. The complicated shape of oil storage caverns, the complicated behavior of salt rocks, and boundary conditions associated with large underground openings are important challenges in the design of oil storage caverns. The aim of this paper is to delve into the stability and deformation mechanisms of storage caverns created in salt domes. A parametric study of effect of the cavern size, orientation, and depth is carried out as a function of ground stress regime. The stress field and deformation mechanisms are calculated for each case aiming at providing design guideline.INTRODUCTIONOne of the most popular soft rock that is used for underground oil storage is salt rock (halite). Salt rock has particular characteristics which makes it suitable for oil storage. Salt rock has several advantages for oil storage, these are: high production rate, high degree of availability, short filling period, high level of safety and low permeability [1]. The low permeability is due to the fact that halite deforms in a plastic manner over a wide range of pressures, temperatures and rates of deformations. This property prevents joints or gaps opening up in the formation, thus preventing the escape of liquids and gases. The state of stresses around the cavern in salt domes depends on the depth of the cavern (initial stresses and rock mass temperatures are increasing with depth), the in-situ stress state within the rock mass, and the internal oil pressure in the cavern. Furthermore, the salt creep behavior and the cavern geometry are influencing stress redistributions during loading and unloading phases.Rock mass structure, cavern geometry, material behavior and cavern operation patterns require complex physical models to describe the load-bearing behavior of the geomechanical structure. The determination of stress, strain and deformation in the rock mass due to cavern construction and operation are complex problems which can be evaluated employing numerical tools such as the Finite Element Method (FEM) or Finite Difference Method (FDM). In this study, the finite difference method was used to evaluate the behavior of oil storage cavern in salt rock."

Jan 1, 2015

"Le présent article porte sur la diminution des rejets de concentrateurs produits durant l’exploitation et le traitement des minerais métalliques.Le minerai dilué envoyé au traitement a, très souvent, un certain pourcentage du stérile qui affecte directement la rentabilité des opérations souterraines et amplifie l’impact négatif sur l’environnement. Les essais de la séparation du stérile et du minerai effectués en milieu dense sur quelques types de la minéralisation d’or, ont démontré les deux possibilités qu’offre cette technique:• Dans le cas d’un minerai riche, il a été possible de séparer la part importante du toutvenant (minerai dilué contenant le minerai et le stérile) provenant de la dilution, tout en ayant un taux de récupération élevé (supérieur à 96%).• Dans le cas d’un minerai ayant une teneur sub-économique à cause d’une dilution importante, il est possible de produire un concentré ayant une teneur économique à l’entrée de l’usine de traitement, en éliminant une partie du tout-venant.En plus la séparation du stérile peut accroître, en outre, la rentabilité de l’exploitation minière, car le fait d’éliminer la partie de stérile le plus tôt possible diminue certains coûts (transport, traitement et autres). On conclue que la pré-concentration du minerai (séparation du stérile et du minerai) est probablement une seule solution actuellement étudiée qui diminue l’impact environnemental de la mine, sans avoir des conséquences négatives sur la rentabilité de l’exploitation souterraine."

Jan 1, 1997

By Z. Y. Liu

A local additional potential model (LAPM) was developed to illustrate the role of strain rate in stress corrosion cracking (SCC) of pipelines. According to LAPM, both density and mobility of the local active spots on the steel surface, i.e., dislocation emergence points, increase linearly with strain rate. Generation of such active spots introduces an additional negative potential locally, affecting the electrochemical reaction and, consequently, the susceptibility of the steel to SCC. Electrochemical corrosion measurements, slow strain rate tests and electrochemical hydrogen permeation test were combined to demonstrate the validity of LAPM to illustrate pipeline SCC in an acidic soil solution. It is found that a maximum of the SCC susceptibility occurs at strain rate of 10-6 s1, which is associated with an enhanced hydrogen evolution due to the local additional potential (LAP) effect.

Jan 1, 2010

By Y. Wang

In this study, homogeneous (unseeded) precipitation of nesquehonite (MgCO3.3H20) by the reaction of MgC12 with (NH4)2CO3 in supersaturated solutions at 30 °C was investigated. Factors which influence the precipitation of MgCO3.3H20, such as initial concentration, temperature, stirring speed, titration speed, equilibration time, have been studied. SEM images show that the initial concentration and titration speed have significant effect on nesquehonite's crystal morphology and particle size. In addition, stirring speed and equilibration time also have some influence on its properties. With the optimization of operating conditions, the crystals can grow up to a length of about 40µm and a width of 5µm, indicating good filtration properties. High purity nesquehonite obtained in this study was calcined to produce highly pure MgO at 800 °C as shown by XRD results. The novel process may be used to separate Mg and Li from high Mg/Li ratio brines in Qinghai, China.

Jan 1, 2007

By M. D. Everell

Le Centre de Recherches minérales (CRM), qui est un organisme de recherche appliquée du ministère de l'Energie et des Ressources du Québec, a été créé en 1969, dans le but de procurer un support scientifique et technique à l'industrie dans le domaine des mines et de la métallurgie. Pour atteindre ses objectifs, le CRM met à la disposition de l'industrie un personnel spécialisé et compétent dont une quarantaine d'ingénieurs et de scientifiques. Etant donné la nature même de l'industrie minérale, ce personnel est très versé dans l'étude des problèmes diversifiés des domaines de la technologie minière, du traitement des minerais, de la métallurgie extractive et de l'analyse minérale. Ce Centre de recherches met également à la disposition de l'industrie une usine-pilote permettant de reproduire les résultats du laboratoire au moyen d'un appareillage de type industriel, d'obtenir des échantillons en quantité suffisante pour une exploration du marché et de familiariser du personnel avec les opérations normales de l'industrie. Certaines de ses contributions récentes au développement de l'industrie minérale du Québec seront présentées.

Jan 1, 1985

By C. Peña, C. A. Zaror, M. Bustamante, M. Vega

The goal of this paper is to present the carbon footprint of Chilean cathodic copper, as a function of the electricity generation mix, ore grade, and process efficiency. Ore grades and acid leach-solvent extraction-electrowinning (LX-SX-EW) yields in the range 0.5-1.0% and 60-80%, respectively, were considered here. Additionally, electricity supply from two Chilean suppliers, SING (1.0 ton CO2/MWh) and SIC (0.4 ton CO2/MWh) was assessed. Simulation results show that oxide plants located in northern Chile, served by the SING network, feature carbon footprint within 4.3 - 11.4 MWh I ton cathodic copper, as compared with 3.5 - 9.3 MWh I ton copper in plants served by SIC. The footprint was found to increase as ore wade and process yields decrease.

Jan 1, 2011

By M. B. Myers

The subject matter of this paper will be discussed under three main headings. 1.-Fire-Resistant Fluids: (a) the need for such materials, based on historical events; (b) a definition of fire -resistant fluids; (c) general description, characteristics, operational parameters, advantages and disadvantages of oil-in-water emulsions (HFB), water-polymer fluids (HFC) and anhydrous or synthetic fluids (HFD). 2.-A review of equipment associated with the use of fire-resistant hydraulic fluids; (a) performance testing of hydraulic equipment, i.e. gear pumps, vane pumps, axial and radial piston pumps, hydraulic motors, etc., pressure, speed, filtration limitations, etc., and effects on valves, elastomers, paints, etc.; (b) hydraulic system design features and selection of suitable units; (c) types of mining applications currently employing fire-resistant fluids. 3.-Test methods used to evaluate fire-resistant fluids: (a) fire testing methods, i.e. wick tests, spray ignition testing, hot manifold tests, factory mutual tests, all to establish fire-resistancy parameters and acceptance; (b) new developments in fire-resistancy evaluation; (c) the examination of other performance tests, e.g., effects of evaporation, sliding wear, life of rolling element bearings, etc.

Jan 1, 1979