Report on the systems lead oxide-alumina and lead oxide-alumina-silica

Geller, R. F.; Bunting, E.N.

doi:10.6028/jres.031.015

Cited by 50 publications

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“…Note: Values in the table were obtained from previously published phase diagrams (Geller and Bunting 1943;Hummel 1984;Levin et al 1964). …”

Section: Sorbent Utilization Limits and Products Formedmentioning

confidence: 99%

“…For modeling purposes, a stoichiometry based on a sorbent utilization twice that of the single-oxide aluminosilicates was used, consistent with the majority of data in Figure 3. Table 1, constructed using information obtained from the phase diagrams for the sodium aluminosilicate and lead aluminosilicate systems (Geller and Bunting 1943;Hummel 1984;Levin et al 1964), lists the possible sodium/kaolinite reaction products and allows direct comparison of each product's metal capture capacity potential. The two sodium aluminosilicate products requiring more than two silicon atoms per product are not realistic products at high sorbent utilizations, because there is not enough silica present in the sorbent.…”

Section: Sorbent Utilization Limits and Products Formedmentioning

confidence: 99%

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Mechanisms and Models Describing Sodium and Lead Scavenging by a Kaolinite Aerosol at High Temperatures

Gale

Wendt

2003

Aerosol Science and Technology

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High temperature mechanisms of interaction between a dispersed kaolinite aerosol and vaporized sodium and lead were investigated using experimental data obtained from an 18 kW downflow furnace. The validity of using aerosol size fractionation to determine the extent of reaction between metal and substrate was confirmed through a series of specialized tests. The reaction stoichiometries for the Na/kaolinite and Pb/kaolinite systems were found to differ from literature values but were similar to each other. New light was shed on the nature of the reaction products for the Na/kaolinite and Pb/kaolinite systems, and for semivolatile metal/kaolinite sorbent systems in general. Modified reaction mechanisms were developed that accommodate key-observed processes (i.e., both enhancing and inhibitory substrate-melting processes). Rate coefficients for each system were quantitatively determined. Mechanisms are interpreted in the light of known information on the structure and nature of kaolin clay and based on observed phase transformations of the Na/kaolinite and Pb/kaolinite systems. The new models for high temperature Na/kaolinite and Pb/kaolinite interactions compared well to both new and literature data. These models can be used to predict and optimize the scavenging of vaporized sodium and lead by kaolinite mineral particles in fossil fuel-fired systems and waste incinerators.

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“…Note: Values in the table were obtained from previously published phase diagrams (Geller and Bunting 1943;Hummel 1984;Levin et al 1964). …”

Section: Sorbent Utilization Limits and Products Formedmentioning

confidence: 99%

Section: Sorbent Utilization Limits and Products Formedmentioning

confidence: 99%

Mechanisms and Models Describing Sodium and Lead Scavenging by a Kaolinite Aerosol at High Temperatures

Gale

Wendt

2003

Aerosol Science and Technology

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“…The relatively low resistance of siliceous bodies of the mullite type may be explained by the low-melting eutectics in the PbO-AI20 3-Si02 system, in which there are four eutectics within the range 694 0 to 704 0 C [28). In the binary system AI20 3-PbO, a eutectic occurs at 865 0 C [28), which no doubt accounts for the appreciable solution of the Al20 a specimen of 99.95-percent purity.…”

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confidence: 99%

“…In the binary system AI20 3-PbO, a eutectic occurs at 865 0 C [28), which no doubt accounts for the appreciable solution of the Al20 a specimen of 99.95-percent purity. No data are availablr.…”

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confidence: 99%

Studies of binary and ternary combinations of magnesia, calcia, baria, beryllia, alumina, thoria and zirconia in relation to their use as porcelains

Geller¹,

Yavorsky²,

Steierman³

et al. 1946

J. RES. NATL. BUR. STAN.

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Barium oxide (BaO).-Introduced as reagent quality BaCOa. Beryllia (BeO).-(1) Commercial "SP grade," usually used in making the porcelain specimens, and nominally of 99.7-percent purity. Spectrograms showed only traces of copper, iron and magnesium, and very weak lines for silicon.(2) Commercial "CP grade," usually used in specimens for fusionpoint and softening-range determinations, nominally of over 99.9-percent purity.Calcium oxide (CaO).-Introduced as reagent quality CaCOa. Magnesium oxide (MgO).-(l) Fused MgO (periclase) of approximately 97-percent purity, usually used in making porcelain specimens.(2) Calcined MgCOa (calcining temperature given by producer as 2,000° F). Very fine grained, purity about 99 percent, and used in a relatively small number of specimens.(3) Especially selected, water clear, crystals of periclase,2 which were hand ground in agate or mullite mortars and usually used in bodies for fusion-point and softening-range tests. The purity is nominally over 99 percent.Silica (Si02).-Pulverized natural quartz of 99.6-percent purity. Strontia (SrO).-Introduced as reagent quality SrC03• Titania (Ti02).-Trade designation "pigment grade," purity about 99 percent, with Fe20a given by the producer as less than 0.2 percent.Thoria (Th02).-Calcined thoria, nominally of over 99-percent purity. Spectrograms showed only very weak lines for calcium, copper, and silicon, and no other impurities were indicated.Zirconia (Zr02).-A CP grade of calcined zirconia, and recalcined at 1,440° C. The spectrogram showed medium lines for columbium and titanium and only very weak lines or traces for calcium, copper, iron, magnesium, lead, and silicon.In order to obtain the desired fineness of particle size, it was necessary to grind the SP BeO, the commercial grade AI20 a, and the Th02• The BeO described above had been ground wet for 2 hours in porcelain-lined mills with flint pebbles. The A120 a and the Th02 had been ground for 48 hr. in a steel mill ",ith steel rods, and then purified by treatment with diluted HOI until the wash water gave a negative test for iron. 3 III. METHODSSpecimens were prepared during the first stages of the work by hand-mixing the ingredients in slip form, drying, pulverizing in an agate or in a mullite mortar, remL'{ing with a 5-percent solution of soluble starch, and pressing in hardened steel moulds. About 14 g of the starch solution was used for 100 g of dry batch, and the forming pressure was 9,300 Ib/in 2 • Later, the method was improved by machine-blunging the slip with a chemical-Iaboratory-type stirrer, and by vibrating the dampened mixture in the steel moulds before pressing. The pressed specimens were matured in an electric furnace, heated with eight Th02-Y20a resistors, described in Bureau Research Paper RP1662 [12]. The heating and cooling rates were maintained very close to 3°0 per min, and the holding time at the maximum temperature usually was 1 hr. A typical setup with three specimens , Furnisbed by tbo Vitrefrax Corporation and by the Norton Co .• Comparative tests were made ...

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“…The filter cake from each test was also analyzed for soluble and insoluble Al, Si, and K. It has been shown [35][36][37] that meta-kaolinte (Al 2 O 3 .2SiO 2 ), kaolinite (Al 2 O 3 .2SiO 2 .2H 2 O), and metal captured in the aluminosilicate crystal structure (i.e., K 2 O.Al 2 O 3 .2SiO 2 ) are not water soluble. However, unbound potassium components (i.e., K 2 O, K, and KOH) and most potassium silicates are soluble in water.…”

Section: Slipstream Test Resultsmentioning

confidence: 99%

Trace-Metal Scavenging from Biomass Syngas with Novel High-Temperature Sorbents

Gale

Walsh

2007

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EXECUTIVE SUMMARYEffective syngas cleanup is one of the remaining major technical challenges yet to be resolved and one that will provide the most benefit to the suite of bio-thermochemical process technologies. Beyond tars and acid gases, which are themselves a significant detriment to reforming catalysts and associated equipment, semi-volatile metals can also damage cleanup systems, catalysts, and contaminate the fungible products. Metals are a difficult challenge to deal with whether using hot-gas filtration or low-temperature processing. Even though most of the metal tends to condense before the barrier filter of hot-gas cleanup systems, some small percentage of the metal (large enough to damage syngas-reforming catalysts, the candle filters themselves, and gas turbine blades) does pass through these barrier filters along with the clean syngas. Low-temperature processing requires expensive measures to remove metals from the process stream. Significant costs are required to remove these metals and if they are not removed before contacting the catalyst, they will significantly reduce the life of the catalyst.One approach to solving the metals problem is to use high-temperature sorbents to capture all of the semi-volatile metals upstream of the barrier filter, which would prevent even small amounts of metal from passing through the filter with the clean syngas. High Temperature sorbents have already been developed that have been shown to be effective at capturing semi-volatile metals from vitiated combustion effluent, i.e., high-temperature flue gas. The objective on this project was to evaluate these same sorbents for their ability to scavenge metals from inert, reducing, and real syngas environments. Subsequently, it was the objective of this project to develop designer sorbents and an injection technology that would optimize the effectiveness of these sorbents at capturing metals from syngas, protecting the barrier filters from damage, and protecting the catalysts and other downstream equipment from damage. Finally, the high-temperature sorbent technology would be expanded to look at the role that these sorbents play in relation to tars and acid gases, which are the other significant pollutants within syngas. In addition to the technology development work described above, all of the information obtained in this work was to be incorporated into a syngas speciation model, which would allow direct prediction of transformations that occur in syngas as it passes from the gasifier and the sorbent-injection section and through the barrier filters.Unfortunately, Congressional budget cuts prevented most of this work from being accomplished. Hopefully, additional funds will be provided to this work in the future, which will allow its completion. However, at the halting point of this project, the following has been accomplished.A major initial objective of the project was accomplished, which was to determine whether or not high-temperature sorbents found to work within vitiated air might also work in an inert environme...

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Report on the systems lead oxide-alumina and lead oxide-alumina-silica

Cited by 50 publications

References 0 publications

Mechanisms and Models Describing Sodium and Lead Scavenging by a Kaolinite Aerosol at High Temperatures

Mechanisms and Models Describing Sodium and Lead Scavenging by a Kaolinite Aerosol at High Temperatures

Studies of binary and ternary combinations of magnesia, calcia, baria, beryllia, alumina, thoria and zirconia in relation to their use as porcelains

Trace-Metal Scavenging from Biomass Syngas with Novel High-Temperature Sorbents

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