The Production of Low Ash Coals Using the Hydrophobic-Hydrophilic Separation Process with Novel Developments

Froth flotation is a common method in mineral processing to separate material based on hydrophobicity. This process becomes less efficient, however, as particle size is reduced. Because of this ultrafine particles are often discarded prior to froth flotation, and contributes to a substantial amount of coal waste in impoundments. An impoundment is a dam built using coarse reject to hold fine reject in slurry. Because of the land-use and risk of an impoundment failure, these impoundments pose an environmental liability. To address ultrafine coal rejection, researchers at Virginia Tech development the hydrophobic-hydrophilic separation (HHS) process. Unlike in froth flotation, HHS uses an organic solvent to separate and dewater hydrophobic particles from hydrophilic minerals. Past work on the HHS process yielded promising results. In particular, the HHS process has produced a low-ash (<2%) and low moisture (<8%) product, which makes it viable for a feed stock for carbon products. With this in mind, the goal of this work is to make the HHS process more robust by improving the understanding of the effects of auxiliary processes, such as grinding, pre-concentration, and reagent conditioning, on the HHS process. This work also contains work on the interaction between two primary unit operations in the HHS process: oil agglomeration and de-emulsification. Lastly, to make the HHS process more viable for commercial scale-up, a novel unit operation called enhanced liquid flotation (ELF) was developed and tested that performs comparably to the current HHS process, but with less unit operations.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mining Engineering

Department dc:contributor.department

Mining Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Youmans, Nathan Charles

Chair dc:contributor.committeechair

• Noble, Christopher Aaron

Committee members dc:contributor.committeemember

• Huang, Kaiwu
• Yoon, Roe H.

• Hydyophobic-Hydrophilic Separation
• Enhanced Liquid Flotation
• Oil Agglomeration
• Low-Ash Coal

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:37583

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/115354