Search Documents

By Joseph Gersic

MINFO has been developed to serve as a frontend for three databases created to store basic minerals information gathered during the minerals resource assessment conducted by U.S. Bureau of Mines(USBM) for the Malheur and Jordan resource areas of southeastern Oregon(MJRA). The primary database is the Minerals Location Inventory (MLI.DBF) which contains of information assembled from field work performed during this project, the USBM Minerals Availability System/Mineral Information Location System(MAS/MILS) database, the Oregon Department of Geology and Mineral lndustries(DOGAMT) Mineral Information Location(MILOC) database, and the U.S. (Geological Survey(USGS) Mineral Resource Database System(MRDS), In addition, assay results are contained in the geochemical database (ELEMENTS.DBF) and modified X-ray diffraction analysis information is contained in the minerals database (MINOR.M.DBF). MINFO includes four types of program modules: ? Enter/Edit Data was developed to allow the addition of new information and to encourage correction of errors by providing a convenient means of entering and editing data and a large degree of automatic checking and filtering of entries. ? ACAD/DBF Link links each site symbol posted on the map in the drawing file to a record in the database. This provides the user with the ability to use a mouse or other pointing device to graphically select a site for viewing and editing. Edits are performed directly in the database file, ? Reports contains 7 formats of data output for creating files for printing, transfer to other database formats, and exporting to other software packages such as spreadsheets and word processing programs. ? Maps includes 5 programs for creating AutoCAD script files which can be used to create maps of selected information in conjunction with AutoCAD. Mineral location mapping files derived from MLI.DBF can be created in 2 formats. Mapping files can be generated from each of the 2 sets of geochemical analyses contained in ELEMENTS.DBF. X-ray diffraction analyses can also be translated into instructions for creating and posting piecharts at sampling sites.

Jan 1, 1994

By Patrick J. Foster

This paper summarises a behavioural safety project undertaken in seven quarries in the UK in order to investigate its applicability as a means of raising the standards of health and safety in the UK quarrying industry. A behavioural safety methodology was developed and trialled at two quarry sites in the UK. During the study the number of unsafe acts and minor accidents had decreased and at one of the quarries there was a 95% reduction in the number of working days lost. It was then introduced at a further five sites of varying sizes and within this focused specifically on lone workers as well as behaviours that affected quality and environmental issues. Positive improvements were noted in most of these operations. The project also looked at the effectiveness of health and safety performance indicators. Here, the common lead and trailing indicators for both safety and health that are commonly used by industry were identified. In consultation with the UK quarrying industry these were then used to identify specific performance measurement criteria that can be used by the quarrying sector to measure performance. Following on from this a quarry specific health and safety management system specification was developed for large and small quarries.

Jan 1, 2008

Tumbling mills and some theoretical and practical aspects of milling are discussed. Attention is directed towards the difficulty of relating the dynamical analyses of the motions of particles within mills to the existing treatments of breakage processes. This synthesis may be advanced by a study of milling that utilizes the matrix analysis of breakage processes. Application of the matrix analysis to results obtained on (i) grinding in open-circuit a zinc ore in a conical pebble mill and in a modified conical mill, (ii) "grinding of cement clinker in a compound mill, and (iii) to some drop-weight grindability tests is discussed. It is shown that the 'IT-breakage model adequately describes the breakage processes of each of the tests. (The proportion broken in each breakage cycle is given by 'IT and is independent of particle size.)The size distributions of the products are accurately predicted in the cases considered. Matrix analyses of the breakage of coals, various ores and a cement clinker have been made. Appendices give an elementary account of the matrix methods and give the equations fully describing reverse order closed circuit operations. The matrix analyses of breakage processes and the survey are used to examine briefly closed circuit grinding.INTRODUCTIONTumbling mills are slow-speed crushing and grinding machines which have been developed from some fairly simple types into many widely differing forms. Many of these versatile mills have proved extremely useful in ore dressing and mineral beneficiation, whereas others have been used in the cement industry and less extensively in the coal industry.The performance of even the simplest tumbling mill is very imperfectly understood, whilst the more difficult problems associated with the balancing of complex milling circuits and with the establishment of the optimum operating conditions for the whole of a complex circuit are even less well apprehended.Our knowledge of the performance of tumbling mills is rather sharply divided into two categories: the first consists...

Jan 1, 1957

By N. A. Eilertsen

This paper presents the results of intermittent study begun in 1956 by the Federal Bureau of Mines of yieldable steel arches and yieldable steel ring sets installed for support of development openings in metal mines. Observations were made of this type of support in several iron mines in the northeast and north-central states. The sets, both arches and rings fabricated in the United States, are made from a hot-rolled, cold bent, structural U-shaped steel section in two weights, 15 pounds and 21 pounds per foot. The lighter section is generally used, It is 4.41 square inches in cross section area, and the calculation is that a 6-foot length of this structural shape installed as a supporting column, will safely carry the same load as a Douglas fir post of the same length but of 22 times the cross-sectional area of the steel.

Jan 1, 1962

By S Robinson, R Perkins, D Barrett, D Kepert, C Fowers

The discovery and delineation of significant mineralisation in the Eliwana region continues Fortescue Metals Group’s strong exploration success. In the decade after the first hole was drilled into Christmas Creek in mid-2004 a total of over 11 Bt of hematite-goethite mineralisation have been delineated supporting the raising of $13 B, construction of five mines, 620 km of rail and a five-berth port. As of June 2014, Fortescue was shipping at the rate of 155 Mt/a. The area including the Eliwana and Flying Fish deposits is one of a number of future growth opportunities that Fortescue is currently evaluating.The Eliwana and Flying Fish deposits occur on the south dipping limb of the Brockman Syncline/Jeerinah Anticline. The Eliwana group of deposits are hosted by the Brockman Iron Formation with the Flying Fish/Broadway group hosted by the Marra Mamba Iron Formation.Structurally the area is dominated by moderate southerly dips of the regional dome and keel style folding. The regional limb is locally cross-cut at a small angle by asymmetric north facing Ophthalmian folds trending 110°. These fold sets, in part, preferentially host subsequent supergene mineralisation. Faulting is only locally apparent.Early phases of exploration commenced in 2006, with mapping of Flying Fish and reconnaissance drilling in 2007. However, due to the concurrent discovery (Clarke et al, 2009) and subsequent fast tracked development of Solomon channel iron deposit and Firetail bedded iron deposit (Simpson et al, 2011) priority was placed on developing Solomon due to its relative proximity to existing Fortescue infrastructure. Staged follow-up drilling of both Marra Mamba and Brockman targets at Eliwana was progressively undertaken from 2008 onward.As of 20 May 2014 a total of 1494 reverse circulation (RC) holes for 54 248 m and 13 diamond holes had been completed, resulting in the delineation of a Mineral Resource of 740 Mt. Exploration via mapping, drilling and metallurgical evaluation of adjacent prospects continues with additional resources expected in the future.CITATION:Barrett, D, Perkins, R, Kepert, D, Robinson, S and Fowers, C, 2015. Geological setting of Eliwana and Flying Fish deposits along the north limb of the Brockman Syncline, Hamersley Province, Western Australia, in Proceedings Iron Ore 2015, pp 219–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Andrew B. Cecala

The Bureau of Mines conducted a brief laboratory study on the 10-mm diam Dorr-Oliver nylon cyclone to investigate (1) whether high wind speed (>300 ft/min), or sampler inlet orientation with respect to wind direction, can introduce errors when sampling respirable dust, and (2) whether any such errors can be reduced by using an inlet shield. Being preliminary in nature, the study was not structured to produce definitive results, but rather to discern likely trends and to indicate whether or not a more in-depth study of the problem is warranted. Photometric mass sensing measurements suggested that as the wind velocity increased, the cyclone sampling directly into the high-velocity airstream tended to oversample, relative to the cyclone sampling in a low-velocity airstream. Orientation of the sampler introduced measurable differences in sampling efficiency at higher wind velocities. A shield placed around the cyclone diminished the effects of wind velocity and sampler orientation on sampler performance. Results of this work offer sufficient evidence to substantiate the need for a more in-depth study.

Jan 1, 1983

By E. Matinde, S. L. Msibi

"The robust nature of alumina refractory materials presents opportunities for their in-process reclaiming and re-use in non-critical applications. Virgin refractories can be substituted with different quantities of reclaimed materials without compromising the quality of the refractory products. In this study, the effect of reclaimed bauxite on andalusite-containing refractory castables for tundish applications was investigated. The recycled bauxite was formulated in different proportions to replace virgin andalusite in the castables. Standard tests were conducted to evaluate the physical, physicochemical, and thermochemical properties of the formulated products. Static corrosion tests were conducted using tundish slag in order to simulate the actual operating conditions. The results show that the standard flow behaviour, open porosity, and bulk density of samples containing up to 22 mass% reclaimed bauxite were comparable to those of the reference castable. However, high-temperature properties such as static corrosion at 1400°C and hot modulus of rupture at 1500°C indicated that there is an upper constraint to the amount of substitution. The study demonstrated direct potential savings of up to 10% when the reclaimed alumina replacement ratio was increased to 22 mass%. IntroductionAlumina-based refractories can be classified into low-alumina, containing less than 50% Al2O3, and high-alumina or bauxite, containing between 50 and 90% Al2O3. High-alumina refractories have widespread applications in high-temperature metal extraction processes due to their outstanding thermochemical and thermomechanical properties and stability (Rebouillat and Rigaud, 2002; Frulli, 2016). The typical chemical composition of refractory-grade bauxite consists of 85–90 wt.% Al2O3, 5–10 wt.% SiO2, 1–2wt.% Fe2O3, 3–4 wt.% TiO2, 0.4–0.8 wt.% CaO + MgO, and 0.20–0.8 wt.% K2O + Na2O (Nyoka et al., 2013). The thermochemical and thermomechanical properties of bauxite-based refractories rely principally on the conversion of the contained silica and alumina to the highly stable corundum (?-Al2O3) and mullite (3Al2O3· 2SiO2) phases (Rebouillat and Rigaud, 2002; Hill and Sehnke, 2006; Garbers-Craig, 2008; Frulli, 2016)."

Jun 1, 2019

By Lawrence F. Johnsen

In 1989, the Connecticut Department of Transportation authorized the evaluation and design for a reconstructed Route 1 bridge over the Quinnipiac River in the City of New Haven, Connecticut. The project extends from the intersection of Route 1 with East Street, easterly for approximately 3/4 mile to the intersection of Route 1 with Wheeler Street and Stiles Street. The reconstructed roadway will be relatively on-line and widened to provide for four lanes of vehicular traffic and a single-track railway line. The existing bascule bridge and approach spans, which were constructed in 1924, will be replaced by a 270-foot span lift bridge and new approach spans. The lift bridge will have a main lift span weighing approximately 3000 tons, second largest after the Burlington Northern Bridge over the Williamette River in Portland, Oregon. The new bridge will widen the navigation channel to 24 0 feet and provide vertical clearances of 13 feet when closed and 62 feet when open. The project is located in an industrial area. Adjacent properties include retail gasoline sales, auto repair, railroad transport and bulk storage of petroleum. Existing structures include the Yale Boathouse and several retaining walls serving as containment dikes for petroleum storage tanks. The Yale Boathouse, located on the east bank of the river, was constructed in 1909-1910 and is eligible for listing in the National Register of Historic Places.

Jan 1, 1993

By Lawrence P. Goldfarb

This paper presents the results of the geotechnical investigation for the repair of the Fashion Island Boulevard Bridge, Bridge No. 350160, in San Mateo, California. The concrete, precast girder bridge suffered considerable damage during the Loma Prieta earthquake. The existing 36-inch, precast, prestressed concrete piles cracked and spalled at their tops. Based on analyses performed by Biggs Cardosa Associates, structural engineers, the piles did not have sufficient strength and ductility to resist the dead plus seismic loads specified in the Caltrans "Bridge Design Specifications". Additional support for the bridge was needed and the repair strategy consisted of installing large diameter pipe piles at the existing bent and abutment locations. This paper describes the geotechnical engineering analysis and design decisions for the large diameter pile design.

Jan 1, 1993

By Zhuokun Cao

Manufacture of aluminum foams still suffer from nonuniformity and poor reproductively for there is lack of basic knowledge of foaming process. In this paper, carbon fibers are used as novel stabilizing additive for aluminum foams, and the structure evolution of aluminum foams with different fiber content was studied. A laser rangefinder was used to detect the expansion rate of different al foams. Al foam samples are solidified at different foaming time to determine its relative density and cell size distribution. Results indicate that the cell size of foams linearly increases with the decrease of density, and the slope of the line is influenced by fiber content. The relationship between expansion ratio, density and cell size of the foams is discussed. It is concluded that the density of resulting foam is influenced by the rate of gravity driven drainage, and its cell size is determined by expansion ratio and foaming time.

Jan 1, 2010

By C. J. Van Niekerk

The study comprised of the investigation into the sensitization characteristics of AISI 409 titanium stabilized ferritic stainless steel during low heat input welding. AISI 409 is a fully ferritic stainless steel used in catalytic converters and tubing for automotive exhaust systems due to the supposition that sensitization does not occur during low heat input welding. Two plates of 2 and 4 mm were tested for sensitization during low heat input welding. The study confirmed that chromium carbide (M23C6) precipitation occurs on the grain boundaries in the heat-affected zone with consequent depletion of Cr adjacent to the grain boundaries during welding. In the 2 mm plate sensitization occurred in the heat input range of 0.1 kJ/mm to above 0.25 kJ/mm and in the 4 mm plate sensitization occurred in the heat input range of 0.2 to 0.9 kJ/mm. Ti stabilization is ineffective at the heat inputs used in this investigation due to the rapid cooling rate through the temperature region where TiC precipitates. The presence of N was found to be detrimental since it consumes Ti on cooling, forming TiN, effectively lowering the amount of Ti available for TiC formation during rapid cooling after welding. Annealing for 5 minutes at 725°C does not improve the sensitization characteristics of the welded plate. There is a linear increase in grain size as heat input increases. The resistance to pitting corrosion decreases in the sensitized, welded plate in theheat-affected zone adjacent to the fusion line of welding. Keywords AISI 409 ferritic stainless steel, sensitization, grain growth, resistance to pitting corrosion, low heat input welding.

Jan 1, 2011

By Paul R. Clark

Outline of Presentation ? Brief review of gasification and IGCC ? Polygenerationand its potential ? Why gasification today ? Major technology providers and their activities ? US initiatives ? Alberta Energy Resources and application of gasification ? CO2 management ? Advantages and barriers to gasification ? Conclusions

May 1, 2006

By Franklin D. Cooper

The value of nonfuel raw mineral production in the United States for 1977 increased over that of 1976 by 5%, from $16.7 billion to $17.5 billion. Metals declined by 5% from $6.1 billion to $5.8 billion, chiefly because of strikes in the iron ore industry and a depressed copper market. Subsidization of mining industries in some foreign countries accounted in part for the excess of copper and some other metals on world markets. Weak metal markets and continued slowdowns in the world economy were the main reasons of the virtual absence of new mine projects. Increasing domestic governmental involvement affecting mineral industry activities, such as pricing controls, public land withdrawals, and the Surface Mining Control and Reclamation Act, effective August 3, continued to be controversial and to be criticized by various segments of the industry.

Jan 1, 1980

By H. P. Greenwald, Irving Hartman, H. C. Howarth

"INTRODUCTION A report of tests of seven small pillars formed from the Pittsburgh coal bed in the Experimental coal mine was given in Technical Paper 605 5/ Five additional pillars were tested between July 1939 and. October 1940. The data obtained, in the later tests permit an extension of the conclusions reached in Technical Paper 605, which appears to be important enough to the mining industry to justify a progress report that will explain briefly what it is and how it was obtained. Full detail of the tests will appear in a second technical paper, preparation of which is deferred so that results of pillar tests now under way my be included.DESCRIPTION OF TESTSExcept for minor improvements in operating details, the five additional tests were made as described in Technical Paper 605, pages 2 to 7. Briefly, the desired pillar was formed from the coal bed, by excavating a passage around it (no explosives were used), and enough material was removed from above to permit installation of the assembly used for applying pressure. Each pillar was tested resting on its original fireclay floor, which was restrained from lateral flow by a ring of concrete. Vertical and lateral movement of the pillars in two directions as measured carefully in all tests."

Jun 1, 1941

By C. O. Aksoy

There is a long history of coal production in Turkey with electric energy generated from power plants since the 1950s. However, the cost of power generation is high. Therefore, it has become necessary to find a means of decreasing production costs to become more competitive in a global market. This paper attempts to economically minimize the overall operating costs of a dragline-shovel-truck system applied at an open pit mine that has fed the Yatagan power plant since 1979, lowering the lignite production cost, and indirectly, the overall electricity generation unit cost. Systems currently in place, as a result of former optimization studies, are time-consuming and expensive to re-implement to comply with today’s very different geometric and economic conditions affecting mining operations. In such cases, rather than re-optimization, it is more viable to identify the parameters that affect the minimum unit cost, via a cost minimization study, allowing present mine equipment to be utilized more efficiently. Unit cost minimization analyses are subject to the capacity of the pool of mining equipment available, combined with the mining block geometry from pre-stripping onwards. In this overall unit cost minimization study, P&H shovels and CAT 777 trucks with capacities of 15 yd3 and 77 tons, respectively, were used in truck-shovel pre-stripping operations. A 65 yd3 Marion 8050 dragline was used to expose the overburden immediately over the coal seam. Pre-stripping bench heights varied from 8 m to 20 m and dragline bench heights from 20 m and 25 m were evaluated to minimize the unit cost of field operations. Total overburden extended to a depth of 60 m (35 m to 40 m for pre-stripping). Minimization analyses performed on the pre-stripping truck-shovel operation, prior to dragline operations, determined that the shovel bench height should be 15 m requiring a dragline bench height of 25 m.

Jan 1, 2005

By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By R. A. Franks, G. F. Friel, J. C. Edwards, A. C. Smith

An evaluation of a nuisance-emissions-discriminating smart mine fire sensor system was made in an operating coal mine. These field evaluations were conducted to determine the sensor system's ability to discern nuisance emissions, such as diesel exhaust, emissions from flame cutting and welding operations or hydrogen gas from a charging station, from real fires and to compare the number of falsely reported fire alarms generated between the sensor system and a standard carbon monoxide (CO) monitor. The sensor system's ability to operate successfully in the working environment of an operating coal mine was also evaluated. The smart mine fire sensor system consisted of four sensors whose data outputs were fused with the use of a neural-network-type computer program. Long-term trials were conducted in a haulage way, a belt entry, and a track entry. The system functioned successfully in the belt entry, in accordance with its developmental goals, where the sensor system even discriminated events not anticipated during development. It was not totally effective in the haulage way and track entry, though, due to a combination of significant diurnal air temperature variations, dust, and mechanically induced vibrations. Also, deteriorating rib conditions contributed to operational problems in the haulage way evaluation. In general, the smart mine fire sensor provided nuisance emissions discrimination and was shown to be a viable new approach for mine atmospheric monitoring, enhancing miner safety. This paper describes the in-mine evaluation of the smart mine fire sensor system and discusses recommendations for improving the system.

By L. Moyd, P. Moyd

The first commercially available portable gamma ray-neutron beryllium detector, the Rerylometer, was developed by the same group that developed the first practical portable scintillation counter, the Scintillo-meter. This group includes Professor George Brownell, of the Geology Department of the University of Manitoba in winnipeg, and his associates, K. I. Roulston, R. w. Pringle, and R. L. Funt, of the Physics and Engineering Departments of the University of Manitoba. A prototype model was tested in the field by Dr. Brownell during the summer of 1958. Commercial production was undertaken shortly thereafter by Nuclear Enterprises Ltd., of Winnipeg, and a license for manufacture and distribution in the U.S. was granted to Isotopes Specialties Co., of Burbank, California, a division of Nuclear Corporation of America. Early in 1959, we were retained by the 'Mining Division of Minerva Oil Co. to Legin a search throughout North America for minable deposits of beryllium, and to train members of their permanent staff to continue the program. The project included literature sur-veys, interviews with members of various federal, state, and provincial agencies, scanning of our own collection of suites of specimens from various mineral occurrences, and the examination of deposits in the field. The value of a beryllium detector to this program was obvious and arrangements were made to procure one as soon as possible, which resulted in our obtaining and using the first instrument that was produced commercially in the U. S. In addition to the commercially available Berylometer, Mr. William Vaughan and his associates, of the U. S. Geological Survey Geophysics Division, in Denver, have developed and tested several experimental instruments based on the same principles. DETECTOR Principles The detection of beryllium is based on the fact that "hard" gamma rays (1.6 MEV and geater), such as those produced by Antimony convert ordinary beryllium (Be9) to Be8 , with the release of a neutron. The neutrons are counted by a scintillator designed to favor neutron responses while suppressing those of gamma rays. 'The instrument is completely selective for beryllium. No other element can interfere. Instrunlentation The Rerylometer itself, which is cylindrical, is about 8 inches in diameter, 13 inches high, and weighs about 11 pounds. (Figs. 1, 2). The principal components include: 1. A disc of wax to moderate (or "thermalize") neutrons. 2. A boron-enriched polyester-zinc-sulphide fluorescent screen. This material produces strong flashes when struck by thermalized neutrons but only weak flashes from gamma rays. 3. A photomultiplier tube. 4. An electronic circuit, complete with one srnall 71/2-volt dry battery. The photomultiplier tube and electronic circuit convert neutron flashes to electrical impulses, but gamma ray effects are almost

Jan 1, 1961

By John H. Johnson

Diesel tailpipe CO, C02, NO, and N02 concentrations by the Emissions Measurement Apparatus (EMA) were found to compare satisfactorily with simultaneous concentrations by instruments in the MSHA engine certification laboratory in Bruceton, Pa. The EMA was then applied to the measurement of LHD vehicle diesel tailpipe gases and smoke opacity in the White Pine and Brushy Creek Mines. A general experimental approach was developed by which instruments could be compared for the measurement of diesel exhaust pollutant concentrations in the 1/2 to 5TLV range. The concentrations are changed by varying engine speed, dynamometer load, and the portion of the exhaust which enters the dilution tunnel. Dräger detector tube diluted exhaust CO, CO2, NO, and NO2 measurements were compared with simultaneously taken portable instrument measurements. Diesel exhaust interference inaccuracies were separated from inaccuracies due to detector tube calibration by comparing the instrument readings with both actual detector tube readings and detector tube readings corrected by recalibration of the detector tubes alongside NBS traceable calibration gases. The detector tubes' accuracy was found to be only slightly affected by diesel exhaust interferences and it was concluded that most measure within certification limits established by the National Institute for Occupational Safety and Health. The effects of 2 exhaust system configurations on the pollutant concentrations in a dead-end heading were studied. Both of the configurations exhausted the gases near the roof, directing them toward the crosscut, and both improved the stratification of the air in the heading, due to the bouyancy of the hot exhaust gases. One of the configurations was a pair of Fume Diluters which diluted the exhaust with air by a 10:1 ratio, and the second system was simply a pair of exhaust pipes, bent to direct the exhaust similarly to the fume dilutors. By redirecting the exhaust, the concentration of C02 measured on the LHD vehicle was reduced by as much as 507, in dead-end headings up to 200 ft long. The Fume Diluters showed no improvement over the simple redesign of the exhaust system.

Jan 1, 1980

By Jesse J. Brown

Over 60 simple; were prepared and forwarded to Dr, S. Z. Toma, TPO, PMSRC as a result of this project. Included among these samples were various low temperature forms of silica. Samples of quartz, cristobalite, and tridymite with iron, manganese, and titanium impurities present were prepared. In addition, a long series of samples both wet ground and dry ground for times from 1/2 to 8 hours were prepared. Numerous miscellaneous samples were submitted which included kaolinite, calcite, muscovite, illite, montmorillonite, Ba3(P04)2, and YPO4 among others, in response to special requests from the TPO. The silica rich portion of selected binary (CA 203-Si02, In 203-Si02, Li20-Si02) Na20-Si02, PbO-Si02, SnO2-Si02, Sn02-Si02 BaGa204-SiO2 and SrGa204-Si02) and ternary systems (Na20-Ga203-Si02 and Li20-Ga203-Si02) was investigated to determine the effects of solid solubility on the stabilization of the high temperature forms of tridymite. In addition to the determination of the extent of these crystalline solubilities, observations were made. on the mechanism of the transformation of silicic acid to tridymite and the rate of the reaction in the presence of foreign ions,

Jan 1, 1973