Figure 4.
Barite dissolution efficiency of macropa and DTPA. (a) Large rocks of crude barite ore were crushed with a hammer. (b) The barite was sieved to isolate particles between 0.5 and 2 mm. (c) To simulate petroleum pipes clogged with BaSO4 scale, columns were filled with barite (3 g), and then solutions of macropa or DTPA (~48 mM) at pH 8 and pH 11 were added. (d) After a soak period of 1 h, ligand efficiency, or the percent of ligand saturated with Ba2+, was determined by measuring the concentration of barium in the eluate by GFAAS.