caa a22 4500 386401187 CHVBK 20180307112159.0 cr unu---uuuuu 161130e198903 xx s 000 0 eng 10.1017/S0885715600016225 doi S0885715600016225 pii (NATIONALLICENCE)cambridge-10.1017/S0885715600016225 Determination of Amorphous Phase in Quartz Powder by X-Ray Powder Diffractometry [Elektronische Daten] A powder diffraction method was applied to the quantitative analysis of amorphous silica in several quartz powders. Two calibration methods, i.e., direct analysis and the standard addition method were examined. Calibration mixtures were made by mixing a standard silica gel powder ground to under 5 μm particle size with a matrix quartz powder which was ground to 10 to 40 μm particle size and treated with NaOH solution to remove the amorphous phase caused by grinding. Intensity of the amorphous halo was measured at 23.0° 2θ, and the background intensity at 53.0° 2θ was subtracted. Linear calibration curves were obtained over the ranges of 0 to 50 wt% by direct analysis and 0 to 20 wt% by standard addition methods, respectively. The analytical results obtained by the two calibration methods were in good agreement with each other. The relative standard deviations for 4.3 wt% of amorphous silica were 4.6% by the direct analysis and 5.4% by the standard addition method. These methods were successfully applied to a correction of reference intensity ratios (RIR) for several quartz powders containing amorphous silica. After the correction for amorphous content, the relative standard deviations of the RIR values for quartz powders became smaller. Copyright © Cambridge University Press 1989 Nakamura Toshihiro Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan Sameshima Katsumi Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan Okunaga Kiyoyuki Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan Sugiura Yoshitaka Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan Sato Jun Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan Powder Diffraction Cambridge University Press 4/1(1989-03), 9-13 0885-7156 4:1<9 1989 4 PDJ https://doi.org/10.1017/S0885715600016225 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0885715600016225 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakamura Toshihiro Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan NATIONALLICENCE 700 1- Sameshima Katsumi Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan NATIONALLICENCE 700 1- Okunaga Kiyoyuki Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan NATIONALLICENCE 700 1- Sugiura Yoshitaka Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan NATIONALLICENCE 700 1- Sato Jun Department of Industrial Chemistry, Faculty of Engineering, Meiji University, Higashimita, Tama-ku, Kawasaki, 214, Japan NATIONALLICENCE 773 0- Powder Diffraction Cambridge University Press 4/1(1989-03), 9-13 0885-7156 4:1<9 1989 4 PDJ CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge