AT55446B - Process for the recovery of the sodium salts in the form of bicarbonate in black liquors from the soda cellulose production, which have been freed from organic substances which can be precipitated with carbon dioxide. - Google Patents

Description

  

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    Of course, after the whole solution has been concentrated, it can also be subjected to dry distillation, with or without the addition of lime and in the presence or absence of superheated steam, with alcohol, acetone, etc. being obtained as a mixture. The solution can also be made acidic with stronger acids to liberate the organic acids. Among the latter, it is advisable to use sulfur dioxide first, through which about half of the total amount of lime is precipitated as insoluble calcium sulphite. The reaction is best done at an elevated temperature to avoid the formation of acidic calcium sulfite. This frees the vinegar and can, if desired, be distilled off directly.

   When the vinegar has been distilled off, the formic acid can be replaced by a stronger acid such as. B. sulfuric acid, cleared and then distilled off.



   Another way of the process is to first remove the calcium sulfite and
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  The syrupy substances can then be separated off directly from the amount of salt by filtering or pressing with or without the addition of water or another suitable solvent. The syrup obtained in this way can be processed further by dry distillation.



  If desired, the potassium salts of the syrupy substances can be subjected to such a dry distillation even before the formic acid is distilled off. When the syrupy
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 which forces the syrup to give off water and carbonic acid and turn into a resinous form; However, this does not apply to lactic acid, which forms an anhydride that is sparingly soluble in water. The syrup resinified in this way can be freed from the amount of salt and lactic acid by washing it with appropriately heated water under pressure, whereby the salts and lactic acid can be dissolved and utilized while the resin remains undissolved.

   Of course, care must be taken when felling sodium bicarbonate
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 The process for regenerating sodium carbonate from black liquors should of course be used at the same time directly on new quantities of table salt, in order to simultaneously produce an inexpensive solution of sodium carbonate to cover all losses of sodium oxide when boiling cellulose-containing substances.



   In all operations involved in this process for the recovery of sodium oxide from black liquor or for the simultaneous recovery of sodium oxide from sodium chloride
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   PATENT CLAIMS:
1. A method for obtaining the sodium salts in the form of bicarbonate in black liquors from the soda cellulose production, which have been freed from organic substances that can be precipitated with carbon dioxide, characterized in that the liquor at a temperature suitable for precipitation of bicarbonate (20 to 400 C) with Ammonia and carbon dioxide is treated.

 

Claims (1)

2. decay according to claim l, characterized in that the filtrate from the bicarbonate precipitation with a suitable strong Bave, such as. P. Kalk, is treated so that ammonia is liberated, while the organic acids form K. ilk salts. EMI2.6 is filtered before or after the removal of ammonia for the purpose of obtaining precipitated resin-acid lime salts.