Analysis of siliceous materials and coal by atomic absorption spectrophotometry with fusion for sample decomposition

• Published in: Talanta (Oxford) Vol. 51; no. 5; pp. 1009 - 1018
• Main Authors: Lau, Oi-Wah, Lam, Lik, Luk, Shiu-Fai
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 28.04.2000; Oxford Elsevier
• Subjects: Ash content; Atomic absorption spectrophotometry; Coal analysis; Earth sciences; Earth, ocean, space; Exact sciences and technology; Flyash; Fusion; Geochemistry; Geochemistry: general, methodology, regional studies; Geological samples; Hydrocarbons; Sedimentary rocks; Siliceous materials; Atomic absorption spectrophotometry; Ash content; Coal analysis; Geological samples; Siliceous materials; Fusion; Flyash; carbonaceous rocks; silica; residual ash; dissolution; fly ash; metals; accuracy; melting; igneous rocks; sample preparation; clay; sedimentary rocks; precipitation; sand; acids; granites; absorption spectroscopy; plutonic rocks; coal; major-element analyses; atomic absorption; clastic rocks
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(00)00286-1

The oxalic acid–lithium carbonate–lithium tetraborate (1:1:1) fusion agent proposed previously for cement analysis is applied to determine the composition of various siliceous samples including granite, clay, flyash, sand and silica fume. For samples with silica content higher than 70%, the sample size had to be reduced from 0.10 to 0.01 g and a recovery factor was needed in silica determination to account for the precipitation of silica during acid dissolution. Attempt has also been made to determine the major metallic elements in coal by fusion directly without the ashing procedure, and the results obtained were good. Further, the ash content of coal was proposed to be determined by establishing a relation between the ash content and the sum of the concentrations of four major oxides (i.e. the oxides of Si, Al, Fe and Ca), and the proposed method is accurate and is time saving compared with that determined by direct ashing at 800°C.