SOLVENT-IN-PULP EXTRACTION OF BORON FROM SLURRIES

Solvent-in-pulp extraction of boron from various slurries has been studied. Extraction of boron from synthetic slurries of quartz, bentonite and from natural plant-end-slurry from Kirka/Turkey with 2-ethyl-1,3-hexanediol (EHD), 2-cloro-4-(1,1,3,3-tetramethyl-butyl)-6-methylol-phenol (CTMP) and 1:1 mixture of the two is considered here. The results show that, under the pulse conditions used, phase separation appeared acceptably sharp and the level of clarity is acceptable regardless of pH. The transmittance evidently decreased with increase in pH but did not drop below about 75%. However, some solid and water were transferred and the organic layers were slightly turbid in decreasing order CTMP>CTMP/EHD>EHD but the phase clarity is reduced by solids in the order quartz>bentonite>water. Combining the data of observed turbidities on extraction with the transmittance measurements of the organic phase rough estimates of solids transferred may be made, For example, in the case of extraction from bentonite slurry at pH 9 the % solids in the organic phase are 0.4, 0.3 and 0.1 for CTMP, CTMP/EHD and EHD respectively, assuming that the solids content of the aqueous phase is 50, 000 gm(-3). Values are of course lower at lower pH. For quartz slurries the corresponding figures are; 0.3, 0.2 and 0.05.