| 摘要 |
<p>1404226 Strontium carbonate preparation KALI-CHEMIE AG 9 Aug 1972 [9 Aug 1971] 37253/72 Addition to 1,288,549 Heading C1A SrCO 3 is continuously produced by reacting SrS soln. with CO 2 introduced at 11 and 10 respectively into an agitated column 1, the gas stream being repeatedly interrupted by structures 5 inside the column which create at least 3 reaction zones A, B and C containing separate gas chambers 7 wherein the CO 2 and the H 2 S formed in the reaction collect and are conducted therefrom by pipes 8 into the next higher zone separately from the liquid, the resulting SrCO 3 being separated from the column at 13. The ratio of CO 2 /SrS input may be controlled by reference at 9 to the conductivity of the reaction liquid in the zone C, the conductivity preferably being kept a constant value in the range 3-10 mS./cm. corresponding to a Sr ion concn. of 2-10 g./l. The concn. of the SrS soln. added at 11 may be 30-70 g./l. and the process may be operated at a temp. of 60-90‹ C. The dried product has a bulk density of 0À4-0À8 g./cc. and a S content of 0À14% which can be reduced by washing with NaOH soln.</p> |
