Formulation studies and grout development for fixation of variable phosphate/sulfate waste, Milestone 195

The objective of this work was to develop a range of cement-based blended dry solids which, when mixed with variable phosphate/sulfate waste (PSW), produce grouts that are processible in the Rockwell Hanford Operations (RHO) Transportable Grout Facility (TGF). The selected formula(s) will also utilize commerically available materials requiring no custom processing and meet all criteria as identified and quantified by RHO, not only for grouts made with the reference formula, but also for those grouts made with reasonable deviations from the reference formula expected during routine TGF operation. This report presents experimental data for processibility and solid performance as well as graphical representations of the data. Based upon the results of the preliminary study, several grout formulas were found that produced acceptable grouts. One such formula, composed of Type III Portland cement (50 wt%), class F fly ash (28 wt%), Attapulgite-150 clay (14 wt%), and Indian red pottery clay (IRPC) (8 wt%), produced acceptable grouts with several of the waste concentrations studied. When mixed with 100% sulfate waste, this blend produced acceptable grouts at mix ratios of 8, 8.5, and 9 lb/gal. This particular blend also produced acceptable grouts at waste concentrations of 25/75 and 75/25 PSW. 12 refs., 27 figs., 13 tabs