Showing papers on "Fly ash published in 1970"

Isotopic composition as a natural tracer of lead in the environment

Abstract: The object of this research was to determine if the isotope ratios of lead were significantly different in various environmental media and if such differences could be used to distinguish the lead in the media. Significant differences in the lead isotopic ratios in rock and soils, grasses, tree leaves and tree rings, air particulate, and in some industrial products such as coal, fly ash, gasoline, and fuel oil have been found. Leaf, grass, and soil samples taken across the New Jersey Turnpike showed a change in lead isotopic ratios from the Turnpike to a point one mile to windward. The mean value of the Pb-206/Pb-204 ratio in topsoil within 500 feet of the Turnpike was 18.2 +/- 0.2 and beyond 500 feet was 18.7 +/- 0.15. Lead sampled from soil profiles in two forested locations in northern New Jersey showed an increase in Pb-206/Pb-204 ratios, with depth from 18.7 to 19.9 in a 30-inch profile. The lead abundance decreased from 47.5 to 12.0 ppm. The mean ratios of Pb-206/Pb-204 from coal and gasoline analyzed were found to be 18.8 +/- 0.2 and 18.3 +/- 0.3, respectively. The mean value for the same ratio in the published data on coal ismore » somewhat higher. Fly ash and the coal from which it came both contained lead of the same isotopic ratio. 8 references, 12 figures, 3 tables.« less

The comprehensive analysis of coal ash and silicate rocks by atomic-absorption spectrophotometry by a fusion technique

Abstract: A simple rapid fusion technique, in which lithium metaborate is used as the fluxing medium, has been developed for the analysis of mineral silicates, coal ash, furnace deposits and other related materials. A single fusion, followed by dissolution in dilute nitric acid, allows the major constituents of the samples to be determined by atomic-absorption spectrophotometry within the following ranges: SiO2 5 to 80 per cent., Al2O3 2 to 60 per cent., TiO2 0·5 to 5 per cent., Fe2O3 2 to 60 per cent., CaO 1 to 40 per cent., MgO 1 to 40 per cent., Na2O 0·5 to 20 per cent. and K2O 0·1 to 10 per cent., with a precision comparable with that of conventional methods used for silicate analysis.

Process for treating aqueous chemical waste sludges and composition produced thereby

Abstract: Waste sludges containing small amounts of certain types of reactive materials are treated by adding to such sludges materials capable of producing aluminum ions, lime and/or sulfate bearing compounds to produce a composition having a sufficient concentration of sulfate ions, aluminum ions and equivalents thereof, and calcium ions and equivalents thereof Fly ash is preferred source of aluminum ions for this purpose Over a period of time such compositions harden by the formation of calcium sulfo-aluminate hydrates Hardening of the sludge facilitates its disposition and may permit the reclamation of the land now occupied by large settling ponds for such sludge Still further, the solidification of such settling ponds may provide permanent land fill which permits immediate use of the land without the necessity for removal of the sludge Aggregate materials may also be incorporated in the solidified waste

Lightweight cements for oil wells

Abstract: DISCLOSED HEREIN IS A LIGHWEIGHT CEMENT WHICH UTILIZES SMALL CENOSPHERES PRIMARLY CONSISTING OF SILICA-ALUMINA. THIS MATERIAL KNOWN AS FLOAT ASH IS ESSENTIALLY THAT PORTION OF FLY ASH THAT FLOATS ON WATER AND HAS SPECIFIC GRAVITY AROUND 0.7. THE LIGHTNESS OF FLOAT ASH AND ITS INHERENT COMPRESSIVE STRENGTH MAKE IT DESIRABLE AS AN INGREDIENT FOR DECREASING THE WEIGHT AND IMPROVING THE STRENGTH OF OIL WELL CEMENTS.

Utilization of coal-burning power plant by-products

Abstract: An aqueous slurry is formed from modified fly ash, i.e., a mixture of alkaline earth sulfates or sulfites, unreacted alkaline earth oxides and fly ash from coal-burning power plant ash collection devices. The slurry, which may contain suitable modifiers, is carbonated with CO2-containing gases, e.g., power plant stack gases, and the resulting carbonates are separated by flotation methods. The separated carbonates are dewatered and dried and may then be reinjected above the combustion zone of the furnace or mixed with the coal to be burned.

Chicken feed composition containing fly ash for weight gain

Abstract: AN IMPROVED CHICKEN FEED COMPOSITION MAY BE MADE BY SUBSTITUTING 1/2 TO 5 WEIGHT PERCENT OF FLY ASH FOR AN EQUAL WEIGHT OF CORN MEAL IN A CONVENTIONAL CORN MEAL TYPE FEED. THE IMPROVED FEED MAY BE RELATIVELY EASILY PELLETED AND REQUIRES A LOWER RATIO OF POUNDS OF FEED TO ACHIEVE A GIVEN DEGREE OF ANIMAL WEIGHT GAIN. THE FEED MAY ALSO CONTAIN A SMALL AMOUNT OF BINDER FOR THE FLY ASH TO REDUCE DUST.

Hydrogen Sulfide Removal From Hot Producer Gas With Sintered Absorbents

Abstract: The Bureau of Mines prepared three sintered materials capable of removing H2S from producer gas at 1000° to 1500°F. They are mixtures of ferric oxide and fly ash, ferric oxide and pumice stone, and red mud (a ferric oxide-containing residue from processing bauxite). All three absorbents were virtually completely regenerable with air. A sintered Fe2O3; (25%)-fly ash [75%) mixture was tested through nine H2S absorption-air regeneration cycles without loss of absorplion capacity or attrition of the pellets. The absorbent with the greatest capacity was a red mud, absorbing 16.0% by weight of sulfur at 1000° F, 24.0% at 1250° F, and 45.1 % at 1 500° F.

Diffusion in Portland Cement Clinker

Abstract: Experimental data on the interfacial reaction between portland cement clinker and molten coal ash at 1400° to 1500°C are consistent with a mechanism involving diffusion in the melt as the rate-controlling step. The formation and growth of well-defined zones between the reactants are characteristic of the reaction. Equations were solved for diffusion with two moving interfaces. On the basis of these equations and data from the lime-alumina-silica phase equilibrium diagram, the diffusion coefficient for CaO in the interstitial melt in the clinker is about 5±10-6 cm2/s at 1500°. The results imply that the clinkering reaction in the burning of portland cement clinker is also controlled by diffusion in the melt.

Evaluation of remolded field samples of lime-cement-fly ash-aggregate mixtures

Abstract: IN LATE SEASON CONSTRUCTION USING LIME-CEMENT-FLY ASH-AGGREGATE (LCFAA) MIXTURES, THE REACTION PROCESS MAY BE GREATLY RETARDED BY COOL TEMPERATURES CONSTRUCTION OF THE RUNWAYS AND TAXIWAYS AT THE NEWARK AIRPORT PROVIDED AN EXCELLENT OPPORTUNITY TO COLLECT THE NECESSARY MATERIALS FOR A STUDY TO DETERMINE IF LIME AND CEMENT DOES MIGRATE OR IS LEACHED FROM THE MATERIALS DURING ADVERSE CLIMATIC CONDITIONS A LABORATORY INVESTIGATION WAS DESIGNED TO DETERMINE THE EXTENT OF LEACHING OR MIGRATION OF THE LIME AND CEMENT UNDER THE FIELD CONDITIONS DESCRIBED AND THE EFFECT OF THE LEACHING AND CURING CONDITIONS ON THE SUBSEQUENT CURING OF THE LCFAA MATERIALS THE TEST PROGRAM CONSISTED OF: (1) TITRATION AND PH TESTS ON ALL FIELD SAMPLES, (2) STRENGTH AND DURABILITY TESTS ON SELECTED SAMPLES OF REMOLDED MATERIAL, AND (3) A LABORATORY STUDY TO EVALUATE LEACHING UNDER CONTROLLED CONDITIONS FINDINGS INDICATE THAT THE LIME AND CEMENT IN THE LCFAA MIXTURES USED IN THE NEWARK AIRPORT PAVEMENTS ARE STABLE AND ARE NOT SUBJECT TO SIGNIFICANT LEACHING OR MIGRATION OVER SHORT PERIODS OF TIME SPECIFICALLY, THE FINDINGS INDICATE THAT THOSE LCFAA MATERIALS PLACED LATE IN THE CONSTRUCTION SEASON WILL RETAIN NEARLY ALL OF THE LIME AND CEMENT THAT WERE ADDED DURING MIXING AND THAT THIS LIME AND CEMENT WILL REACT WITH OTHER COMPONENTS OF THE MIXTURE UNDER FAVORABLE CONDITIONS EVEN AFTER BEING DORMANT FOR A CONSIDERABLE PERIOD FINDINGS INDICATE THAT THE MORE EXTENSIVE CURING IS BEFORE FREEZING AND THAWING, THE LESS DAMAGE WILL BE DONE TO THE MATERIALS BY CYCLIC FREEZING AND THAWING MATERIALS DAMAGED BY FREEZING AND THAWING WILL RECOVER A SIGNIFICANT PORTION OF THE LOST STRENGTH UNDER FAVORABLE CURING CONDITIONS PROVIDED SUFFICIENT LIME AND CEMENT ARE RETAINED IN THE MIXTURE TO SUPPORT CONTINUING REACTIONS IT WAS OBSERVED THAT WHEN THE LCFAA MATERIALS ARE SUBJECTED TO ALTERNATE FREEZE-THAW CYCLES UNDER THE CONDITIONS USED IN THIS STUDY, THE MOST SEVERE DAMAGE TO THE MATERIALS OCCURS NEAR THE TOP OF THE SPECIMENS FOR A DEPTH OF FROM 1 TO 2 INCHES

Ceramic product from fly ash and method of making same

Abstract: THE INVENTION RELATES TO A CERAMIC PRODUCT COMPRISING THE WASTE ASH MATERIAL OBTAINED FROM COAL-BURNING INDUSTRIAL POWER AND OTHER PLANTS, AND TO THE METHOD OF PRODUCING THE SAME. ESSENTIALLY, THE INVENTION IS A PROCESS FOR PRODUCING A SUBSTITUTE FOR CONVENTIONAL CLAY OR SHALE CERAMIC PRODUCTS WITH PROPERTIES AT LEAST EQUIVALENT TO THOSE PRODUCTS BY THE USE OF VERY NEAR TO 100% OF THE WASTE ASH MATERIAL NORMALLY CALLED FLY ASH, BOTTOM ASH, CLINKER, ETC.

Properties of compacted sewage ash

Abstract: PROPERLY COMPACTED SEWAGE ASH FROM A LOCAL TREATMENT PLANT EXHIBITS SUFFICIENT STRENGTH AND STABILITY TO RECOMMEND ITS USE ON A TRIAL BASIS AS A BACKFILL, LIGHTWEIGHT STRUCTURAL FILL, OR SUBBASE MATERIAL. LIME IS ADDED DURING SEWAGE TREATMENT, AND SUBSEQUENTLY IS CONCENTRATED IN THE ASH RESIDUE AS A RESULT OF INCINERATION. THE HIGH LIME CONTENT OF THE ASH IS LARGELY RESPONSIBLE FOR ITS AGE-HARDENING PROPERTIES AND RESISTANCE TO MOISTURE AND FROST. THE COMPACTION CHARACTERISTICS OF SEWAGE ASH ARE SIMILAR TO THOSE OF A CONVENTIONAL SOIL, EXCEPT THAT MAXIMUM DRY DENSITIES ARE LOWER AND OPTIMUM WATER CONTENTS ABOUT DOUBLE. USE OF COMPACTED SEWAGE ASH IN CIVIL ENGINEERING PRACTICE WOULD SERVE A TWO-FOLD PURPOSE,VIZ., WASTE DISPOSAL ON THE ONE HAND, AND PROVISION OF A LIGHTWEIGHT FILL OR EMBANKMENT MATERIAL. /AUTHOR/

Prediction of fly ash performance

Abstract: IT IS SHOWN THAT THERE IS A HIGH DEGREE OF CORRELATION AMONG CERTAIN PROPERTIES OF FLY ASH, WHICH PERMITS THE USE OF MULTIPLE FACTOR ANALYSIS TO PREDICT THE PERFORMANCE OF FLY ASH IN CEMENT, MORTARS, AND CONCRETE. THE ADVANTAGES OF THIS TECHNIQUE TO PRODUCERS AND USERS OF FLY ASH ARE THAT THE BEHAVIOR OF FLY ASH IN MORTAR AND CONCRETE COMPOSITIONS IS MORE CLEARLY EXPLAINED; SPECIFICATIONS CAN BE SIMPLIFIED, BOTH WITH RESPECT TO THE NUMBER OF DIFFERENT TESTS THAT MAY BE REQUIRED AND TO THE EXPENSE OF RUNNING THE TESTS, AND IN CERTAIN CASES LABORATORY TESTS INVOLVING LONG TERM CURE PERIODS CAN BE ELIMINATED; AND CONFLICTING STATEMENTS AND CONCLUSIONS MADE IN PREVIOUSLY REPORTED STUDIES CAN BE RESOLVED. VISUAL COMPARISONS OF SAMPLES OF FLY ASH UNDER MICROSCOPIC EXAMINATION SUPPORT THE MATHEMATICAL FINDINGS.

New or underdeveloped methods for producing and utilizing coal ash

Abstract: PRODUCTION OF PRESENT AND FUTURE ASH MATERIALS AND SOME OF THE LESSER KNOWN UTILIZATION TECHNIQUES ARE DISCUSSED. AN ANNOTATED BIBLIOGRAPHY OF 194 REFERENCES OON ASH UTILIZATION IS APPENDED. /AUTHOR/

Factors affecting the frost susceptibility characteristics of pulverized fuel ash

Abstract: The results of laboratory studies of the frost susceptibility characteristics of pulverized fuel ash are presented. Four different ashes were investigated, in their plain state, and also after stabilization with ordinary Portland cement and calcitic hydrated lime. Measurements were made of frost heave, permeability, compressive and tensile strength, and heaving pressure. Frost heave was shown to decrease as the strength increased and as the permeability decreased. Values of strength and permeability were found at which the frost heave was reduced to an acceptable value, and the relative importance of strength and permeability in reducing frost heave is discussed. The heaving pressures mobilized are compared with the corresponding compressive and tensile strengths of the ashes.

Lightweight concrete aggregate from sintered fly ash

Abstract: LIGHTWEIGHT CONCRETE AGGREGATE IS BEING PRODUCED COMMERCIALLY FROM PULVERIZED COAL FLY ASH BY SEVERAL PLANTS. THE PRODUCTS ARE OF GOOD QUALITY, ALTHOUGH THEY VARY SOMEWHAT WITH RESPECT TO SHAPE AND SIZE. THE TYPE OF FLY ASH USED IN THE MANUFACTURING PROCESS IS GENERALLY THAT PRODUCED FROM BITUMINOUS COAL. THE CHARACTERISTICS OF FLY ASH THAT ARE REQUIRED IN THE FORMING AND SINTERING PROCESS ARE DESCRIBED. A DESCRIPTION OF THE PHYSICAL PROPERTIES OF THE FLY ASH AGGREGATE IS PRESENTED. THE EVALUATION OF THESE AGGREGATES BY THE USE OF ASTM METHODS GIVES A GOOD INDICATION OF THE PERFORMANCE OF THE VARIOUS MATERIALS IN STRUCTURAL CONCRETE. COMPARISONS ARE PROVIDED BETWEEN OTHER TYPES OF LIGHTWEIGHT AGGREGATE CONCRETE AND, IN ALL CASES, THE FLY ASH CONCRETE SHOWS A FAVORABLE RANGE OF PROPERTIES. CONCRETE STRENGTHS IN EXCESS OF 6,000 PSI (420 KG/SQUARE CM) CAN BE PRODUCED WITH FLY ASH AGGREGATE. OF SIGNIFICANCE IN MAKING COMPARISONS IS THE HIGH RATE OF ABSORPTION OF THE AGGREGATE, THE RESIDUAL POZZOLANIC ACTIVITY, AND THE RELATIVELY LOW CEMENT FACTORS REQUIRED FOR LEAN CONCRETE. INFORMATION IS PRESENTED ON TYPICAL MIX DESIGNS FOR USE IN STRUCTURAL CONCRETE. /AUTHOR/

Leachable boron from fly ash

Abstract: An experimentally observation was conducted to determine boron in fly ash with Inductively Coupled Plasma Spectrometry (ICPS). Sample of solution from fly ash mixed with distilled water was analyzed for pH, agitation time, boron concentration and temperature. It was revealed that fly ash released soluble boron rapidly about 25%-30% from total boron content. Desorption of boron ions occurred afterwards. After immersion in more than one day, sorption of boron by fly ash increased with increasing pH, up to 13. The equilibrium state transpires after fly ash contact with water. Aluminum borates may release soluble boron to the solution while alkalinity of fly ash is believed to lead particles on fly ash surface to capture boron ions.

Additive injection for sulfur dioxide control. A pilot plant study. Research report

Abstract: A small pilot plant that burns pulverized coal was used to evaluate a dry limestone injection process More than 400 tests were performed with over 100 different limestones or dolomitic-type additives to evaluate their effectiveness for reducing sulfur dioxide emission under a variety of test conditions Some of the major variables studied include temperature at the point of additive injection, residence time of the additive in the reactive zone, additive/sulfur ratio, additive surface area and chemical form of the additive The effects of the additives on ash deposition and fly ash resistivity were also studied The process is considered only as a stopgap measure when applied as the sole means for removing SO/sub 2/ from flue gas Under certain conditions additives can produce or aggravate furnace-wall slagging and ash deposition problems Electrical resistivity of reacted additive-fly ash products is increased, which will decrease performance of electrostatic precipitators (GRA)