| 摘要 |
<p>The chromium (III) carbonate of the present invention exhibits a light blue color in a solid state. This chromium (III) carbonate has an L* value of 50 to 70, an a* value of -4 to -2, and a b* value of -10 to -7, which are represented by the L*a*b* color system (JIS Z8729). This chromium (III) carbonate is preferably completely dissolved within 30 minutes when the chromium (III) carbonate is added, in an amount corresponding to a Cr content of 1 g, to 1 liter of an aqueous solution of hydrochloric acid having a pH of 0.2 at a temperature of 25°C. This chromium (III) carbonate is preferably obtained by contacting an aqueous solution of carbonate and an aqueous solution containing trivalent chromium at a pH of 6 to 12 under the condition of a reaction liquid temperature of 0°C or more and less than 50°C. Also, preferably, after production of the chromium (III) carbonate, filtration is performed, and the chromium (III) carbonate is washed with water until the conductivity of the filtrate is 5 mS/cm or less.</p> |
