| 摘要 |
PURPOSE:To prepare uniform calcium carbonate crystal of a single shape selectively with high yield by allowing carbonate ion to react with a Ca compd. in aq. soln. under irradiation of supersonic wave. CONSTITUTION:Crystals of calcium carbonate are formed by dropping aq. soln. of a Ca compd. (e.g. CaCl2) with ca.60-20,000ml/hr dropping rate into an aq. soln. contg. carbonate ion (e.g. aq. soln. of sodium carbonate) under stirring to cause reaction. In this case, the reaction is proceeded by applying >= ca.10kHz supersonic wave. By this method, a single shape crystal of calcium carbonate is selectively obtd. (for example, aragonite type needle crystal: ca.60-80 deg.C; aragonite type spindle-shaped crystal: ca.40-55 deg.C; calcite type cubic crystal: ca.20-30 deg.C; batholite type spherical crystal: ca.10-15 deg.C. Note: Temp. ranges given in parentheses show respective reaction temps.).
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