| 摘要 |
1. Continuous process for making manganese carbonate which combines high purity with regular particular size, high apparent density and good oxidizability to gamma-manganese dioxide, and which is obtained in good space/time-yields by precipitating it from a manganese(II) salt solution by means of a diammonium carbonate solution, while maintaining during the precipitation a molar ratio manganese/carbonate of about 1 : 1 and a precipitation temperature of 20 to 80 degrees C, introducing the manganese salt solution and the diammonium carbonate solution into the precipitation apparatus through inlets widely spaced apart from one another and intensively stirring during the precipitation, characterized in that a) a manganese(II) salt solution containing ammonium salt and a diammonium carbonate solution containing ammonium salt are used, of which the manganese(II) salt solution containing ammonium salt contains 0.3-1.5 mol/l manganese(II) salt and 0.1-2.2 mol/l ammonium salt, especially 0.1-1.1 mol/l ammonium sulfate or 0.2-2.2 mol/l ammonium nitrate, and the diammonium carbonate solution containing ammonium salt contains 1.0-3.0 mol/l diammonium carbonate and 0.4-3.0 mol/l ammonium salt, especially 0.4-1.5 mol/l ammonium sulfate or 0.8-3.0 mol/l ammonium nitrate, and presents a pH value of 7.8-8.2 ; b) 1.0-3.0 m**3 /h manganese(II) salt solution containing ammonium salt is used per m**3 utilizable volume of the precipitation apparatus, and c) a pH-value of 7.8-8.2 is established in the precipitation apparatus by the addition of ammonia. |
