TY - JOUR
T1 - Leaching rate of hematite in hydrochloric acid solutions in agitated vessel
AU - Matsumoto, Katsutoshi
AU - Taniguchi, Shoji
AU - Kikuchi, Atsushi
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1994
Y1 - 1994
N2 - A kinetic study on the leaching of Fe2O3 in HCl solutions has been made by using agitated vessel to clarify the mechanism of the rate acceleration which was found in the previous study for Fe2O3-HNO3 system. Powder specimens with various sizes were prepared by a wet classification of ground powder obtained from pellets sintered at 1623 K (I) and 1523 K (II). The specific areas of these specimens were measured before and after the leaching experiments. Leaching rates were found to be independent of the agitation speed. Leaching rates under various conditions were correlated by the following relationship: r = 20.0(1+5.4α1.6) Sw0 exp (-94000/RT)CH(+)CCl(-), where α is the fraction dissolved, Sw0 the initial specific area of the specimen, T temperature, C concentration of ionic species. As seen in the above correlation, the leaching rate increased with increasing α. In order to clarify the mechanism of the rate acceleration, a leaching experiment was carried out by using a sintered Fe2O3 disk of which surface was polished and exposed to a HCl solution. Same as the previous study, only the (0001) oriented crystal planes were found to dissolve and its dissolution rate increased with time. The fractional area of the (0001) plane was about 25%. Assuming the same fractional area for the powder specimen, the increase in the overall surface area was well estimated.
AB - A kinetic study on the leaching of Fe2O3 in HCl solutions has been made by using agitated vessel to clarify the mechanism of the rate acceleration which was found in the previous study for Fe2O3-HNO3 system. Powder specimens with various sizes were prepared by a wet classification of ground powder obtained from pellets sintered at 1623 K (I) and 1523 K (II). The specific areas of these specimens were measured before and after the leaching experiments. Leaching rates were found to be independent of the agitation speed. Leaching rates under various conditions were correlated by the following relationship: r = 20.0(1+5.4α1.6) Sw0 exp (-94000/RT)CH(+)CCl(-), where α is the fraction dissolved, Sw0 the initial specific area of the specimen, T temperature, C concentration of ionic species. As seen in the above correlation, the leaching rate increased with increasing α. In order to clarify the mechanism of the rate acceleration, a leaching experiment was carried out by using a sintered Fe2O3 disk of which surface was polished and exposed to a HCl solution. Same as the previous study, only the (0001) oriented crystal planes were found to dissolve and its dissolution rate increased with time. The fractional area of the (0001) plane was about 25%. Assuming the same fractional area for the powder specimen, the increase in the overall surface area was well estimated.
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U2 - 10.2320/jinstmet1952.58.3_297
DO - 10.2320/jinstmet1952.58.3_297
M3 - Article
AN - SCOPUS:0028383686
VL - 58
SP - 297
EP - 302
JO - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
JF - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
SN - 0021-4876
IS - 3
ER -