[en] This report discusses results of a plant demonstration of the double shell slurry process which was conducted April 25 to 28, 1977. 274,000 gallons of double shell slurry were produced from 365,000 gallons of Hanford Defense Residual Liquor. The volume reduction was 25%. Process control was maintained near the proper zone in the early part of the run. However, the feed was underconcentrated in the latter part of the run. Hydroxide concentrations of the product samples ranged from 2.1 to 5.9 M. The aluminum to caustic ratio varied from 0.33 to 1.07. The solids were primarily sodium nitrate, carbonate, aluminate, and nitrate. All samples were totally water soluble. The double shell slurry product increased in volume by 19,000 gallons from April to October 1977, probably caused by organic chelating agents