| 摘要 |
<p>The invention relates to a method for producing granular coated sodium percarbonate with a low TAM value. The sodium percarbonate is produced by fluid bed granulation at a temperature TG in the range of from 45 to 75 °C and coating by spraying an aqueous solution that contains at least one coating component in a fluid bed at a temperature TU in the range of from 35 to 100 °C. According to the invention, a) after fluid bed granulation but before coating a supplementary drying step is carried out at TNT of greater than TG, or b) fluid bed granulation is carried out in at least two steps at TG1, TG2 TGn, with TG2 or TGn being greater than TG1 and no supplementary drying step being required if 2/3 of the granules have been formed at TG1, or c) supplementary drying is carried out not after granulation but only after coating, namely at TUNT, with TUNT being at least 20 °C higher than TG.</p> |
