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This study explores the formation of MnO precipitates on glass surfaces through oxidation and leaching treatment. The reduction of Mn ions, leaching process, and MnO precipitation are examined. The original glass structure, inter-lamellar voids, and changes in appearance from opaque to brown and iridescent are observed and analyzed over varying time periods. Transversal and longitudinal planes are used to study the progression of MnO formation closer to the glass surface. The evolution of the glass surface characteristics is documented through 30 figures capturing different stages of the process.
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+II +II +III +III reducing reducing + + + + Mn Mn , , Mn Mn Na Na ,K ,K , ... , ... treatment treatment oxidation oxidation leaching leaching O O , H , H O O 2 2 2 2 ? ? Mn Mn 2+ 2+ leached glass leached glass original glass original glass inter inter - - lamellar void lamellar void ? ? MnO MnO precipitates precipitates 2 2 white, opaque white, opaque white, opaque iridescent, opaque iridescent, opaque iridescent, opaque brown brown brown - - yellowish yellowish yellowish uncorroded uncorroded , clear , clear (a) months, months, (b) months, months, (c) hours, hours, (d) years years years years days days Fig. 02
a b Fig. 04
Transversal plane Longitudinal plane 1 Longitudinal plane 2 Longitudinal plane 3 0 min 180 min 270 min Fig. 06
a b to glass surface Fig. 07
0 min 180 min 270 min Fig. 08
0 min 180 min 270 min Fig. 09