VERFAHREN ZUR VERRINGERUNG DER BEI DER TONERDEHERSTELLUNG NACH DEM BAYER-VERFAHREN AUFTRETENDEN AETZNATRONVERLUSTE BEZIEHUNGSWEISE ZU DEREN ERSATZ

1436261 Reducing NaOH loss in Bayer process ALUTERY ALUMIMUMIPARI TERVEZO VALLALAT and FEMIPARI KUTATO INTEZET 18 May 1973 23900/73 Heading C1A A method of reducing the loss of NaOH during alumina production according to the Bayer process wherein NaCl is added to the digestion liquor such that a concentration of 1-40 g./l., preferably 5-20 g./l. is maintained therein. The addition of NaCl is preferably continuous NaCl may also be added to recycling digestion liquor after addition of NaOH to bring NaOH concentration to 250-500 g./l. to NaCl concentration of 20-80 g./l. to salt out Na 2 .CO 3 .