摘要 |
A method and installation for the production of a coarse-grained ammonium sulfate product by crystallization includes firstly generating a crystal having a grain smaller than the desired grain size in a pre-crystallizer and withdrawing a suspension therefrom, from which the fine crystal was previously separated in a classification connecting piece. This suspension, which contains medium-sized grain, is then conducted with a proportion of undersaturated mother liquor, which is sufficient for further crystal growth, into a DTB product crystallizer and crystallized therein to a desired grain size. The heating of the product crystallizer is performed by the heat contained in the vapors of the pre-crystallization. The pre-crystallization may also operate according to the DTB principle, wherein the mother liquor needed for crystallization is supplied in the form of separately admixed concentrated sulfuric acid and ammonia into the external solution loop of the pre-crystallizer. The reaction heat released in this case may be sufficient for the operation of the entire process.
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