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Title: Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth

Abstract

Up until Dec 2016, the thermal agglomeration was very heuristic, and as such, difficult to define. The lack of predictability became problematic, and the current notes represent the first real attempt to systematize the specification of the agglomerated process parameters.

Authors:
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1348996
Report Number(s):
LLNL-TR-727422
DOE Contract Number:
AC52-07NA27344
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

Citation Formats

Hodge, N. E. Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth. United States: N. p., 2017. Web. doi:10.2172/1348996.
Hodge, N. E. Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth. United States. doi:10.2172/1348996.
Hodge, N. E. Wed . "Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth". United States. doi:10.2172/1348996. https://www.osti.gov/servlets/purl/1348996.
@article{osti_1348996,
title = {Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth},
author = {Hodge, N. E.},
abstractNote = {Up until Dec 2016, the thermal agglomeration was very heuristic, and as such, difficult to define. The lack of predictability became problematic, and the current notes represent the first real attempt to systematize the specification of the agglomerated process parameters.},
doi = {10.2172/1348996},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Mar 22 00:00:00 EDT 2017},
month = {Wed Mar 22 00:00:00 EDT 2017}
}

Technical Report:

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  • The computer program written in support of one dimensional analytical approach to thermal modeling of Bridgman type crystal growth is presented. The program listing and flow charts are included, along with the complete thermal model. Sample problems include detailed comments on input and output to aid the first time user.
  • The overall purposes of this study were to establish practical methods for characterizing the surface hydrophobicity of coal and for measuring other interfacial properties involved in the oil agglomeration process, and to determine how these properties control the oil agglomeration process. It was hoped that this study would provide a better understanding of the mechanism of the oil agglomeration process in order to aid process optimization.
  • Oxidation of Upper Freeport coal deleteriously affects the oil agglomeration process for the beneficiation of fine coal. In this process, fine coal is suspended in water and contacted with a small amount of oil or hydrocarbon-liquid such as n-heptane. The latter was used in the work reported here. The hydrophobic nature of the unoxidized coal surface leads to bridging of the coal particles by the oil or heptane, while the ash-forming minerals tend to be more hydrophilic and are not agglomerated. Subsequent recovery of the larger coal aggregates on sieves is then possible. Surface oxidation by air in a laboratorymore » oven at 150/sup 0/C renders the coal surface more hydrophilic and reduces the recovery dramatically from near 100% for the unoxidized coal to as little as 20%. Surface oxidation leads to an increase in oxygen-containing functional groups, which seems to cause the increase in hydrophilicity. Analytical chemical techniques revealed increasing concentrations of both carboxyl and hydroxyl groups over increasing periods of oxidation; FTIR spectroscopy revealed similar trends with the augmentation of the peaks corresponding to the expected oxidative products associated with coal. Incorporation of the anionic surfactant sodium oleate rendered the oxidized coal surface less hydrophilic, leading to enhanced recovery. On the other hand, the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) had little effect on oxidized coal recovery. 60 refs., 20 figs.« less
  • The report gives results of an evaluation of the potential of thermal agglomeration as a means of enhancing the collection of fine particle emissions. Available theoretical and experimental information indicates that this method of particle agglomeration offers no useful avenue for improving fine particle control. (GRA)