Patent ID: 6110377
Filing Date: 2000-08-29
Classification: C01D,C01F

Abstract:
Process for removing insoluble sodium contained in alkaline waste, comprising the steps of:placing an RH.sup.+ type cation exchange resin in direct contact with the alkaline waste in an amount sufficient to complex some or all of the insoluble sodium contained in the waste and forming an homogeneous aqueous suspension;allowing a contact time that is sufficient to provide transfer and attachment of insoluble sodium in the waste to the resin,separating the resin charged with the sodium from the alkaline waste;contacting the sodium-charged resin with lime and water to form a resin and lime suspension in water;allowing a sufficient contact time between the resin and lime suspension to provide a calcium-charged resin;separating a concentrated soda solution from the calcium-charged resin;recycling the separated concentrated soda solution to a digestion liquor used in a Bayer process; andoptionally regenerating the RH.sup.+ cation resin with a diluted mineral acid which can form a neutralized calcium salt.