Studies of coal dust wetting by surfactant solutions

The identification of the dust characteristics in coal mine working faces is essential for preventing coal dust explosion and occupational diseases. In this paper, dust samples from the coal mines in southern Shanxi province and Henan province, central North China, were selected as the research objects. The results show that the dust contains primarily organic matter, as well as considerable amounts of minerals. The chemical composition of dust at the working faces is the most complex. According to the proportion of PM10, the dust composition can be divided into three types: symmetrical, fine-dominated, and coarse-dominated. The wettability of dust increases with the increase of the oxygen–carbon ratio on its surface, increase of ash content, decrease of fixed carbon content, and decrease of particle size. In addition, the great variety of harmful elements in dust, some with a high content, can harm the human body. An explosion index is proposed to evaluate the likeliness tendency of coal dust explosion based on several key affecting factors. The surfactant (0.05% AN solution) adopted in this paper can significantly increase the wettability of coal dust and inhibit the generation of dust greatly, showing good ability in preventing coal dust explosion and occupational diseases.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characteristics of Dust in Coal Mines in Central North China and Its Research Significance

Ding

Zhuang

2020

“…Glanviller and Haley 10 used the Walker test to study various factors affecting the wetting rate of coal dust. The results show that the wetting rate is mainly related to the temperature, the particle size composition of coal dust, and the surfactant used.…”

Section: Introductionmentioning

confidence: 99%

Influence Mechanism of Surfactants on Wettability of Coal with Different Metamorphic Degrees Based on Infrared Spectrum Experiments

Zhang

Zhou

et al. 2021

Based on experiments, a numerical analysis is used to quantitatively explore the influence of coal and surfactant microstructures on wettability. First, based on an infrared spectrum experiment, the distribution of oxygen-containing functional groups, aromatic hydrocarbons, and aliphatic hydrocarbons of coal and surfactants was obtained. Second, the wettability relationship between coal and different surfactants was determined by optical titration, and the coal dust wettability and surfaces were optimized. The key factors of the active agent wetting ability affecting lignite wetting mainly depend on the carbonyl, ether, and carboxyl groups in the surfactant. The factors affecting non-stick coal and gas coal wetting mainly depend on the ether group and aromatic amine in the surfactant. The factors affecting fat coal wetting mainly depend on the ether group and hydroxyl group in the surfactant. Finally, the factors affecting coking coal and anthracite wetting mainly depend on the surfactant ether group, aliphatic amine, and aromatic amine. Then, combining the structural parameters with the coal wetting results, the quantitative mathematical relationship between coal dust wettability, the important influencing factors of the surfactant, and the wettability index was established. Finally, a perfect and reasonable wettability evaluation model between coal and the surfactants was established. The relative activity of methyl ether and aromatic ether is greater than that of methyl ether, and the influence on the lignite, coking coal, and anthracite wettability conforms to the model . The influence on the non-caking coal and fat coal wettability conforms to the model , while the influence on the gas coal wettability conforms to the model Z = A + B 1 X 1 + B 2 X 2 . In general, this study provides scientific guidance for the compounding of high-efficiency and environmentally protective composite dust suppressors to realize clean mine production.

“…Regarding the influencing factors of the wetting ability of surfactants on coal dust, James O et al 24 studied various factors affecting the wetting rate of coal dust by measuring the wetting rate of the wall. The experimental results showed that the wetting rate is mainly related to the temperature, the particle size, the composition of the coal dust, and the types and characteristics of the surfactants used.…”

Section: Introductionmentioning

confidence: 99%

Micromechanism Analysis of Surfactant Wetting of Coal Based on ¹³C NMR Experiments

Zheng

Liu

et al. 2021

With the gradual improvement in coal mine mechanization and automation, the dust concentration at production sites is increasing significantly as the production efficiency improves, which not only poses a substantial threat to the occupational safety and health of workers but also affects the safe production and social stability of mines. At present, wet dust removal is the most economical and effective technical dust removal measure. However, most coal seams in China have poor wettability, unclear microscopic wetting mechanisms, and poor dust removal effects. Therefore, based on experiments and numerical analysis, this paper qualitatively studies the influencing factors of surfactants on coal wettability and quantitatively constructs an innovative evaluation model of the influence of the microstructure of coal and surfactants on wettability. First, based on 13C NMR experiments, the structural parameters of coal and several surfactants were obtained. Second, the wettability relationship between the coal and the surfactants was determined by optical titration, and the key factors affecting the wettability of coal dust and the wettability of the surfactants were selected. Then, using numerical analysis and function fitting analysis and combining the structural parameters with the coal wetting results, the relationship between the microstructure of the surfactants on different kinds of coal and the wettability of the coal samples was established. The results show that the ether group, the phenol or aromatic ether carbon, the fatty methyl group, and the aromatic methyl group in the surfactants have a substantial influence on the wettability. The research results can provide scientific guidance for the development of efficient and environmentally friendly compound dust suppressants to realize clean production in mines.