Method for Hydraulically Separating Carbon and Classifying Coal Combustion Ash

A method for selective separation of particles from a particle-containing material includes preparing a slurry of the particle-containing material and a dispersant, passing the slurry through a hydraulic classifier in a first direction, establishing a particle flow in a direction that is different from the first direction, and recovering particles having a mean particle size of about 2-7 μm. The flow of particles defines a cross-current flow relative to the slurry feed direction. The method further includes providing the classifier with an interior divider assembly defining at least one inclined channel. The divider assembly typically includes a plurality of substantially parallel dividers separating the classifier into multiple channels having a substantially equal internal volume. A hydraulic classifier for separating particles having a mean particle size of from about 2-7 μm in accordance with the present method is provided also

Technology and Methodology for the Production of High Quality Polymer Filler and Super-Pozzolan from Fly Ash

A novel method for producing fly ash material with a range of particle sizes from about 2.0 to about 4.0 μm is provided utilizing superplasticizers. The method produces fly ash material suitable for use as filler material in the plastics industry and super pozzolan for the concrete industry

Proppant for Use in Hydraulic Fracturing to Stimulate a Well

A proppant for use in hydraulic fracturing to stimulate a well is provided. The proppant is fly ash particles having a mean particle size (d50) of between 45 μm and 150 μm and a size distribution defined by (d10) ≤ 5 μm and (d98) ≤ 250 μm

Advanced Multi-Product Coal Utilization By-Product Processing Plant

The overall objective of this project is to design, construct, and operate an ash beneficiation facility that will generate several products from coal combustion ash stored in a utility ash pond. The site selected is LG&E's Ghent Station located in Carroll County, Kentucky. The specific site under consideration is the lower ash pond at Ghent, a closed landfill encompassing over 100 acres. Coring activities revealed that the pond contains over 7 million tons of ash, including over 1.5 million tons of coarse carbon and 1.8 million tons of fine (<10 {micro}m) glassy pozzolanic material. These potential products are primarily concentrated in the lower end of the pond adjacent to the outlet. A representative bulk sample was excavated for conducting laboratory-scale process testing while a composite 150 ton sample was also excavated for demonstration-scale testing at the Ghent site. A mobile demonstration plant with a design feed rate of 2.5 tph was constructed and hauled to the Ghent site to evaluate unit processes (i.e. primary classification, froth flotation, spiral concentration, secondary classification, etc.) on a continuous basis to determine appropriate scale-up data. Unit processes were configured into four different flowsheets and operated at a feed rate of 2.5 tph to verify continuous operating performance and generate bulk (1 to 2 tons) products for product testing. Cementitious products were evaluated for performance in mortar and concrete as well as cement manufacture process addition. All relevant data from the four flowsheets was compiled to compare product yields and quality while preliminary flowsheet designs were generated to determine throughputs, equipment size specifications and capital cost summaries. A detailed market study was completed to evaluate the potential markets for cementitious products. Results of the study revealed that the Ghent local fly ash market is currently oversupplied by more than 500,000 tpy and distant markets (i.e. Florida) are oversupplied as well. While the total US demand for ultrafine pozzolan is currently equal to demand, there is no reason to expect a significant increase in demand. Despite the technical merits identified in the pilot plant work with regard to beneficiating the entire pond ash stream, market developments in the Ohio River Valley area during 2006-2007 were not conducive to demonstrating the project at the scale proposed in the Cooperative Agreement. As a result, Cemex withdrew from the project in 2006 citing unfavorable local market conditions in the foreseeable future at the demonstration site. During the Budget Period 1 extensions provided by the DOE, CAER has contacted several other companies, including cement producers and ash marketing concerns for private cost share. Based on the prevailing demand-supply situation, these companies had expressed interest only in limited product lines, rather than the entire ash beneficiation product stream. Although CAER had generated interest in the technology, a financial commitment to proceed to Budget Period 2 could not be obtained from private companies. Furthermore, the prospects of any decisions being reached within a reasonable time frame were dim. Thus, CAER concurred with the DOE to conclude the project at the end of Budget Period 1, March 31, 2007. The activities presented in this report were carried out during the Cooperative Agreement period 08 November 2004 through 31 March 2007

Hybrid Cement Clinker and Cement Made from That Clinker

A hybrid cement clinker incorporates specific ranges of clinker phases and falls within specific modulus values as set forth and described in this document

Method for Improving the Pozzolanic Character of Fly Ash

A method for improving the pozzolanic character of fly ash includes the steps of first hydraulically classifying and then flotation separating the fly ash in order to reduce particle size distribution and remove carbon. The method also includes the steps of spiral concentrating separated coarse particles to recover iron, pyrite and marcasite and screening the fly ash to remove ultra-light carbon and plant debris

Cementitious Compositions

The invention provides a cementitious composition comprising a cement component comprising (i) an accelerant, (ii) a calcium sulphate source and (iii) an ettringite forming cement; an aggregate; and optionally water; wherein the cement has a minimum unconfined compressive strength of 1500 psi when tested in accordance with ASTM C1140 and/or C1604 at 15 minutes after placement; methods for its use and concrete formed from it

Advanced Multi-Product Coal Utilization By-Product Processing Plant

The objective of the project is to build a multi-product ash beneficiation plant at Kentucky Utilities 2,200-MW Ghent Generating Station, located in Carroll County, Kentucky. This part of the study includes an investigation of the secondary classification characteristics of the ash feedstock excavated from the lower ash pond at Ghent Station. The market study for the products of the processing plant (Subtask 1.6), conducted by Cemex, is reported herein. The study incorporated simplifying assumptions and focused only on pozzolan and ultra fine fly ash (UFFA). It found that the market for pozzolan in the Ghent area was oversupplied, with resultant poor pricing structure. Reachable export markets for the Ghent pozzolan market were mostly locally served with the exception of Florida. It was concluded that a beneficiated material for that market may be at a long term disadvantage. The market for the UFFA was more complex as this material would compete with other beneficiated ash and potential metakaolin and silica fume as well. The study concluded that this market represented about 100,000 tons of sales per year and, although lucrative, represented a widely dispersed niche market

Interfacial Bond between Reinforcing Fibers and Calcium Sulfoaluminate Cements: Fiber Pullout Characteristics

The results of an experimental investigation on the influence of the interfacial bond of reinforcing fibers embedded in a calcium sulfoaluminate matrix on the fiber-pullout peak load and energy consumption are presented. Bonding at the fiber-matrix interface plays an important role in controlling the mechanical performance of cementitious composites—in particular, composites formed from sulfate-based systems (calcium sulfoaluminate [CSA] cements), as opposed to the silicate systems found in portland cement. Various types of fibers were selected, including polyvinyl alcohol (PVA), polypropylene, and copper-coated steel. The fibers were embedded in three different matrixes: two sulfate-based cements including one commercially available CSA cement and a CSA fabricated from coal-combustion by-products. The third matrix was a silicatebased ordinary portland cement (OPC). In this study, the results of the single-fiber pullout test were coupled with scanning electron microscopy (SEM) to examine the interfacial bond between the fiber and CSA matrix for evidence of debonding and possible hydration reaction products

Low-Silica and High-Calcium Stone in the Newman Limestone (Mississippian) on Pine Mountain, Harlan County, Southeastern Kentucky

The coal industry of Kentucky is an important market for limestone. Coal producers use limestone as rock dust for explosion abatement in underground coal mines and as a neutralizing agent in surface-mine reclamation and acid-drainage control. Crushed stone is also used for constructing and maintaining haulage roads. In the Eastern Kentucky Coal Field, the coal-bearing rocks of Pennsylvanian age generally do not contain limestones that are thick enough to quarry or mine economically. But movement on the Pine Mountain overthrust fault has brought the Newman Limestone (Mississippian) to the surface along Pine Mountain in the southeastern part of the coal field. The Newman on Pine Mountain in Harlan County was sampled at 1-foot intervals to determine its chemical quality and potential for industrial use, particular as low-silica rock dust. The sampled section contains two zones of low-silica stone, 64 and 25 feet thick, averaging 0.82 and 1.01 percent silica (SiO2), respectively. Intervals of high-calcium limestone are present in the low-silica zones. These deposits are potentially suitable for use as rock dust in underground coal mines and as neutralizing agents in surface-mine reclamation and acid-drainage control. The intervals of chemically pure stone in Harlan County may be sufficiently thick to produce by selective quarrying or underground mining. Exploitation of the Newman deposits, however, will be complicated by the steep southeastward to southward dip (13 to 42°) of the beds, displacement along small faults within the limestone, and fracturing