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| Prototype Technologies |
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Below is information related to Prototype Technologies.
| Title: |
Total elimination of slurry ponds |
| ISSN: |
0747-3605 |
| Author: |
Battista, Joseph J.; Hughes, Evan E. |
| Abstract: |
The National Aggregates Association rates slurry fines as the number one problem facing today's crushed stone, sand, and gravel producers. But the amount of material reporting to settling ponds can be decreased, water volume or quality problems can be reduced or eliminated, and slurry ponds also can be eliminated. The problem can be solved in two or three phases that include fines recovery by cyclone technology, water clarification, and fines dewatering with belt filter presses. |
| Abbreviated Serial Title: |
Rock Prod |
| Title: |
Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media |
| ISSN: |
0920-8119 |
| Author: |
Darmody, Robert G.; Green, William P.; Dreher, Gary B. |
| Abstract: |
Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasibility of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) Were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3/FeS2/ ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all the mixtures. Tall fescue and sweet clover grew well in all the treatments, but birds foot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method. |
| Abbreviated Serial Title: |
Int J Surf Min Reclaim Environ |
| Title: |
Improving Densification of Fine Coal Refuse Slurries to Eliminate Slurry Ponds |
| ISSN: |
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| Author: |
CAER, University of KY |
| Abstract: |
Increased mechanization in the underground coal mining industry has decreased selectivity and increased the amount of refuse created. Coal preparation separates non-combustible material from coal. Thus, a coal preparation plant separates the material it receives into a product stream and a reject stream, which may be further divided into coarse and fine refuse streams. Depending on the source, 20 to 50 % of the run-of-mine material ends up in reject streams. One of the reject streams is a slurry stream. This is a blend of water, coal fines, silt, sand, and clay particles, which is commonly disposed of in an impoundment. There have been several incidents of impoundment breakthrough. Of these, Buffalo Creek in West Virginia in 1972 and recently, Martin County Coal in Kentucky, have drawn the attention of federal and state governments and local people due to heavy losses of life and property. In this project an advanced thickening technique known as “Paste Thickening Technology” marketed by the Dorr-Oliver EIMCO was evaluated at a coal preparation plant in West Virginia for the dewatering of fine coal tailings. The Deep Cone ThickenerTM is specially designed to concentrate tailings into a high percent solid, so it can discharge as a paste. The thickened paste material could be stacked at a low angle of repose rather than stored in a pond. Thus, with utilization of this technique it is anticipated that the fine refuse slurry ponds could be completely eliminated. The results obtained at the Coal Clean Corporation coal preparation plant showed that the Deep Cone ThickenerTM was able to dewater the conventional thickener underflow material and produce a paste containing about 52.5 wt. % solids. The dewatered solids had the same moisture content as obtained by a belt filter machine. The Deep Cone Thickener TM was also able to dewater the centrifuge drain slurry, which consisted of clean coal product to about 70 wt. % solids. |
| Abbreviated Serial Title: |
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| Link: |
http://www.caer.uky.edu/caerseminar/patil.shtml/
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| Title: |
New strategies for dewatering coal |
| ISSN: |
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| Author: |
M.S. Seehra, A. Manivannan and M.E. Bachlechner |
| Abstract: |
A two-year innovative research program on the combined experimental-modeling studies of coal-water interactions and coal dewatering is proposed. The experimental program will first focus on determining the relative amounts of "free" and "bound" water in wet coals using analytical techniques of thermogravimetric analysis, heat capacity measurements and 1H nuclear magnetic resonance. Laboratory scale dewatering experiments will then be carried out by vacuum filtration and centrifugation, combined with pulsed heating at microwave or IR (3300 cm-l) frequencies to liberate the "bound" water. These investigations will be complimented with modeling studies of the coal-water interactions and the effect of centrifugation on dewatering from surface-bound water and coal pores. This integrated experimental-modeling approach is an important component of the proposed research since the results from the molecular-dynamics simulations could provide unique technological insights that will increase the efficiency of dewatering processes. Finally, scale-up of the resulting successful approaches for coal dewatering will be proposed at the conclusion of the two-year program. |
| Abbreviated Serial Title: |
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| Link: |
http://www.nrcce.wvu.edu/cast/dewatering.htm
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