3-ZONE APPROACH FOR PRECIPITATION OF BARIUM-SULFATE

The three-zone approach, introduced by Gosele and Kind [1] [Chem. Ing. Tech. 63 (1991) 59], has been used to investigate BaSO4 precipitation . Experimental relations for the growth and nucleation of BaSO4 are fo und that show good agreement with those of Angerhofer [2][Thesis, TU M unchen, 1994] and Van der Leeden [3][Thesis, TU Delft, 1991]. The para meters studied in the three-zone approach are the feed concentration, circulation time and volume of the zones. Preliminary results show tha t the model used correctly predicts the influence of the above-mention ed parameters on the mean particle size and the conversion. Experiment s conducted at various mixing conditions in the 3 zones show that the influence of the parameters becomes stronger when the mixing in the 3 zones becomes less intensive. This influence cannot be explained by th e present model, which assumes that the zones are ideally mixed.