Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1929. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed October 7, 2009) Includes bibliographical references (p. 20) and index (p. 21-22).

Thesis (M.S.)--Brigham Young University. Dept. of Geological Sciences, 2008. / Includes bibliographical references (p. 53-57).

Thesis (Ph. D.)--University of Rhode Island, 2004. / Typescript. Includes bibliographical references (leaves 263-280).

Thesis (M.S.)--Virginia Polytechnic Institute and State University. / Vita. Abstract. Includes bibliographical references (leaves 75-76). Also available via the Internet.

Coal powered power plants account for more than 40 percent of the electricity production of the United States. The combustion of coal results in a large number of solid waste materials, or coal combustion byproducts (CCBs). These waste materials are stored in landfill or ponds. The construction industry is heavily reliant on concrete which is used to make the building blocks for any type of structures, bricks. Concrete is a composite material made of a binder and coarse and fine aggregate. The most widely used binder in concrete production is Ordinary Portland Cement (OPC). Since cement manufacture is costly and environmentally damaging, research has increased in recent years to find a more readily available binder. This study aims at investigating the properties of Illinois fly ash as a binder in the production of geopolymer concrete. Geopolymer concrete is an innovative material made by using Alumina and Silica rich materials of geological origins as a binder as well as an alkali activated solution. Sodium Silicate and Sodium Hydroxide were used to make the activator solution of two different ratios. Geopolymer Concrete with a ratio of 1:1 of Sodium Silicate to Sodium Hydroxide reached a compressive strength above 6000 psi while samples made with a ratio of 1:2 reached a compressive strength above 4000 psi. This environmentally-friendly, green concrete was also found to have a cost comparable to conventional concrete.

Since a substantial amount of coal combustion byproducts (CCB) are produced each year, generating value-added product from fly ash, which is a major constituent of these CCBs, has been an important area of research for several decades. Natural magnetite (NM), which is used to maintain dense medium slurry pulp density in coal preparation plants, has a current market value of more than $200 per ton. The use of fly ash derived magnetite (FAM) as an alternative to natural magnetite has potential benefits for dense medium processes, such as lower cost, greater stability at low medium density, more efficient delivery systems. This study developed a suitable processing scheme to extract high-grade (> 96%) magnetite from fly ash generated from burning high sulfur coal, and investigated the suitability of the FAM product for dense medium application in coal preparation plants. A classifying cyclone was utilized in the process flow sheet for the pre-concentration of FAM in its underflow stream, which was enriched to high grade FAM by a single stage wet magnetic separator of low intensity (~1000 gauss). A statistically designed experimental program was utilized to maximize the magnetite grade and recovery achieved from the above mentioned flow sheet. The FAM product particles had a slightly coarser particle size distribution than the NM particles. In addition, the FAM particles were found to have a spherical shape; but about one unit lower specific gravity in comparison to the NM particles. However, the F5 Stability Index of the resulting FAM product was found to be in the desired range of 30 to 40 for its suitable application as a dense medium. The coal cleaning performance obtained from a 0.15 m diameter dense medium cyclone using dense medium prepared from both of FAM and NM, were quite similar. However, the effective separation density (SG50) obtained from the FAM-based dense medium was significantly different from the medium density; this may need further investigation in future. A preliminary economic analysis, conducted for a hypothetical mini-plant having a fly ash handling capacity of 100 ton/hour, indicated the cost of FAM extraction to be nearly $5/ton. The cost assumes that the FAM extraction plant is located at the fly ash producing utility site and does not include the cost of thermal drying that may be required to reduce the moisture content of the FAM filter cake produced at the FAM plant. A preliminary civil engineering study conducted to investigate the effect of FAM extraction on the compressive strength property of the non-magnetic flyash (left behind after FAM extraction) failed to produce a conclusive finding. The specimens prepared using 10% and 30% fly ash replacements indicated that the compressive strength does not change due to FAM extraction. However, the specimens using 20% fly ash replacement indicated that compressive strength does change due to FAM extraction. Hence, a more detailed study is recommended to investigate this discrepancy.

No description available.

No description available.

No description available.

I takt med ökande intresse för uttag av grot så ökar också intresset för återföring av aska tillbaka till skogen. I rapporten utreds hur mycket återföringsbar aska som produceras av förbränningsanläggningar. Arbetet begränsas genom att endast förbränningsanläggningar med större kapacitet än 10 GWh träbränsle per år tas med . Dessutom sker en avgränsning geografiskt till att endast ta med anläggningar placerade söder om en tänkt linje mellan Karlstad och Stockholm. Datainsamlingen för förbränningsanläggningarnas askmängder har gjorts både med telefonintervju och enkätundersökning. Totalt har 107 förbränningsanläggningar tillfrågat. Askan från anläggningarna används till askåterföring, sluttäckning av deponi, deponi och bärlager till vägar. Kostnaderna mellan de olika användningsområdena varierar stort, kostnaderna att sluttäcka en deponi är hälften mot att spridas i skog. En stor del av förbränningsanläggningarna är överens att kostnaderna för askåterföring till skogen är för dyr. Fler anläggningar kan tänka sig att återföra askan till skogen men anger kostnaderna som orsak till val av andra alternativa användningsområden. / In line with increased interest for using of branches and tops, increases also the interest for retransfer of ash back to the forest. In the report investigated how much ash from the incineration plants that can retransfers back to the forest. The work is limited through that only incineration plants with bigger capacity than 10 GWh wood fuel a year is taken with. Moreover, a demarcation happens geographic to only to take with plants placed south about an intended line between Karlstad and Stockholm. The data collection for the incineration plants ash quantities have been done both with telephone interview and questionnaire survey. Total has 107 incineration plants consulted. The ash from the plants is used to ash retransfer, end coverage off landfill, landfill and berry stocks to roads. The costs between the different use areas vary bigly, the costs to end to cover landfill is the half against being disseminated in forest. A big part of the incineration plants is agreed that the costs for ash retransfer to the forest is for costly. More plants can intend itself to bring back the ash to the forest but because of the price the plants choice other alternative use areas.