Preparation and evaluation of lignite flotation collector derived from waste hot-pot oil. (1st May 2020)

• Record Type: Journal Article
• Authors: Cheng, Gan; Zhang, Mengni; Cao, Yijun; Lu, Yang; Feng, Yuxin; Zhao, Shiyu
• Is Part Of: Fuel. Volume 267(2020)
• Publication Date: 2020-05-01
• Subjects: Lignite -- Flotation -- Waste hot-pot oil -- Collector; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2020.117138
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: The waste hot-pot oil from the catering industry was used as a potential coal flotation collector. Response surface methodology was used to optimize WHPO collector preparation. WHPO possessesd strong collecting ability and good selectivity. Abstract: Due to poor hydrophobicity, large amounts of petroleum-based collectors are required for upgrading lignite. In this paper, Waste Hot-pot Oil (WHPO) collectors from the catering industry were prepared via filtration, heating, and catalysis. The catalytic experiment was optimized using the Design-Expert software. The optimum catalytic conditions were found to be a pyrolysis temperature of 85 °C, alcohol-oil ratio of 35:1, catalyst dosage of 2%, and reaction time of 1 h. The Separation Efficiency (SE) of WHPO was 3.04 percentage higher than that of the conventional collector (kerosene), while the ash content of Lignite Surface Treated with WHPO (LWHPO) was 1.14 percentage lower than that of kerosene. Response surface methodology was used to analyse the factors influencing the SE; the effect of the studied factors followed the order catalyst amount > alcohol-to-oil ratio > reaction temperature. GC–MS showed that WHPO contained both long-chain alkyl groups and other ester and hydroxyl groups. XPS tests confirmed that the hydrophobic group (CC, CH) content of LWHPO increased, while its hydrophilic group content (except CO) decreased, demonstrating the improved hydrophobicity of lignite after WHPO treatment. FT-IR analysis indicated that WHPO more effectively decreased the content of hydrophilic groups and increased the content of hydrophobic groups than kerosene. Contact angle (CA) analysis showed WHPO was more conducive to lignite surface hydrophobicity improvement than kerosene. WHPO possessed strong collecting ability and better selectivity, and could be used as an alternative collector for lignite flotation.