著者

宮坂 正三 早川 典久

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.81, no.930, pp.886-893, 1965-10-25 (Released:2011-07-13)

参考文献数

6

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There are many limonite deposits genetically related to the mineral springs at the vicinity of the Azuma Volcano, Fukushima Prefecture. Near the Nuruyu Spa three limonite deposits are found, and the mineral water shows highly acidity owing to the presence of sulphuric acid.This paper is concerned with studies on the chemical compositions of both mineral waters and limonites, and the relation between the pH of mineral water and limonite depositions. It seems probable, on the basis of the experimental evidence, that the optimum pH range for the iron depositions is 3.5-6.0 and that in this pH range iron precipitation is increased with higher pH. Differential thermal analysis curves and X-ray powder diffraction patterns show that the limonites deposited from the mineral springs essentially _consist of amorphous iron hydroxide containing a small quantities of goethite. Odo or yellow limonite from Akanuma and Fukuo shows the clear X-ray powder diffraction patterns of goethite.And as the result of experiments, it is shown that various minerals such as goethite, lepidocrocite, magnetite, and siderite are formed in accordance with the change of pH from 5.0 to 12.0 when NaOH or (NH4) 3CO3 solution is added to ferrous sulphate solution containing sulphuric acid or oxalic acid.