Sources And Characteristics Of Quartz Dust In Coal Mines

Author : Saboor Ahmad Torabi
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (142 download)

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Download or read book Characterization of Forms of Silica with Varying Degrees of Crystallinity in Respirable Mine Dust written by Saboor Ahmad Torabi and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coal was, is, and will be one of the major energy sources for our society. Coal mining activities, from extraction to utilization, intrinsically produce coal dust and its associated aerosols, which are known to be safety and health hazards. Within the mine dust aerosols, the exposure of the respirable crystalline silica (RCS) dust is the most toxic component for the coal workers. Excessive RCS exposure can potentially cause the development of disabling and irreversible lung disease which is known as silicosis. The silicosis cases and its related mortality trend are still high in the United States, and the recent resurgence of coal miners' lung disease sends an alarming sign for the industry. Characterization of the physiochemical properties of RCS is the prerequisite for the improved understanding of its toxicity and adverse effects on miners' respiratory system. In this study, the mineral composition of respirable coal mine dust (RCMD), and type (s) of crystalline silica with its varying degrees of crystallinity in the mine dust were investigated. For this purpose, samples were collected from the top of coal (ToC) and bottom of coal (BoC) rock strata, which are believed to have the highest amount of crystalline silica. In addition, we also collected rock samples from both the roof and pillar of a limestone mine in Pennsylvania to define its crystalline components for potential silica characterization. After preparing the lab-generated respirable dust using a cryomill, the X-ray diffraction (XRD) technique in combination with JADE software was employed to identify the mineral phases and determine the quantitative mineral composition. The results from the quantitative analysis revealed that quartz (crystalline silica), muscovite, kaolinite, and clinochlore are the most abundant minerals in the ToC and BoC strata. The average amount of crystalline silica (quartz) was assessed to be 25% in the ToC and 17.3% in the BoC samples from the Lower Freeport coal seam. The quartz content in the samples from the ToC strata of Lower Kittanning was found to be 16.5%. Furthermore, phase identification analyses determined that, among the quartz types, alpha quartz ([alpha]-quartz) is the only type that exists in the samples. The quantitative analysis also reported a considerable amount of amorphous content for all samples. The amorphous content associated with the samples from near the coal seam comparatively showed a higher quantity, suggesting that the coal-ToC and coal-BoC interfaces contain a significant amount of amorphous. The quantitative analyses of limestone samples reported high calcite and dolomite with negligible quartz content. The amount of quartz in the sample from the pillar of the limestone mine was 0.22%, whereas no quartz was reported for the sample from the roof of the same mine. According to the results, it is advisable to conduct additional elemental analysis to verify the mineral composition of the samples. Additionally, it is recommended to undertake comprehensive investigations into the mineralogy and toxicity of the amorphous content found in coal mine dust, especially those originating from the interfaces of coal and rock strata.