Mössbauer Spectroscopic Characterization of Iron in Ashes Made from the Ancient Woods Excavated in the Foothills of Mt. Chokai

Abstract

2. Experimental 2.1. Umoregi wood and soil samples. The sample ashes were made from umoregi woods excavated from Nikaho City in Akita Prefecture, Japan, located to the northwest of Mt. Chokai (Figure 1) in 2015. Umoregi wo ods were the stems of trees buried by large-scale landslides from Mt. Chokai ca. 2500 years ago. 9, 10 The material umoregi woods were Japanese oak (Quercus serrata or Quercus crispula), Japanese chestnut (Castanea crenata), Japanese cedar (Cryptomeria japonica), and Japanese zelkova (Zelkova serrata). "Japanese" is hereinafter abbreviated as "Jpn." such as Jpn. cedar. These umoregi woods were divided into two groups based on their color. One group looked brown or dark green, and the other group showed black. The former contained Jpn. cedar and Jpn. zelkova umoregi woods, and the latter, Jpn. chestnut and Jpn. oak umoregi woods. After removing soil and bark, the umoregi woods were dried indoors at ambient temperature for several months, and then cut into ca. 5 cm square blocks. Soil was collected at the excavation site of a Jpn. zelkova umoregi tree. The soil was ground in a mortar after air-drying. 2.2. Aqueous solution including Fe 2+ and Fe 3+. Aqueous Fe 2+ and Fe 3+ solution was prepared using Fe(NH 4) 2 (SO 4) 2 • 6H 2 O and FeNH 4 (SO 4) 2 • 12H 2 O. Fe 2+ /Fe 3+ ratio and total Fe concentration in this solution were 3/7 and 2 w/w%, respectively. Special-grade Fe compounds were purchased from Wako Pure Chemical Industries, Ltd. and used without further purification.

Mössbauer and Raman characterization of ash produced by burning ancient buried Japanese cedar and investigation for its unusual color tone

“…The elements for which the molar percentage is less than 0.10% are omitted from the table. As is expected from the previous study [1], Fe was concentrated considerably in the three umoregi-wood ash samples compared with MA. The XRF elemental-analysis results could provide two important pieces of information about the Fe-containing species.…”

“…Furthermore, experts or advanced learners of the Japanese tea or traditional incense ceremonies rate the ash made from umoregi wood, which displays various unusual colors, as top-quality ash in an incense burner or a brazier. However, there have been no reports examining the ash made from umoregi wood other than our previous work [1]. We investigated the coloring mechanism of ash obtained from the combustion of four species of umoregi trees excavated from the foothills of Mt.…”

“…As described in our previous studies [1][2][3], "umoregi" is the most common Japanese term that refer to ancient trees buried or submerged as a result of natural phenomena (e.g., landslides, debris, avalanches, and ground subsidence) over several centuries ago. This term is generally applied to the ancient trees that have not been substantially denatured in terms of their physical properties and main chemical constituents.…”

“…We investigated the coloring mechanism of ash obtained from the combustion of four species of umoregi trees excavated from the foothills of Mt. Chokai in 2015 [1]. The Mössbauer spectra of some ash samples made from umoregi wood showed obvious magnetic hyperfine splittings; however, satisfactory curve-fitting analysis could not be carried out, owing to the broad and…”

Characterization of black slags obtained during smelting in the electric arc furnace from SIDERPERU following reduction

“…The ratio of the area between octahedral and tetrahedral sites is around 1.8 and this value is related to the lower Mössbauer fraction in Fe 2+ /Fe 3+ (Site B) than in Fe 3+ (Site A) [19]. The last two sextets correspond to Ca 2 Fe 2 O 5 with octahedral and tetrahedral Fe 3+ sites with B hf =50.6 a 41.9 T [20,21].…”