WASTE REMEDIATION USING IN-SITU MAGNETICALLY ASSISTED CHEMICAL-SEPARATION

The magnetically assisted chemical separation process (MACS) combines the selective and efficient separation afforded by chemical sorption w ith the magnetic recovery of ferromagnetic particles. This process is being developed for treating the underground storage tanks at Hanford. These waste streams contain cesium, strontium, and transuranics (TRU) that must be removed before this waste can be disposed of as grout. T he separation process uses magnetic particles coated with either 1) a selective ion exchange material or an organic extractant-containing so lvent (for cesium and strontium removal) or 2) solvents for selective separation of TRU elements (e.g., TRUEX process). These coatings, by t heir chemical nature, selectively separate the contaminants onto the p articles, which can then be recovered from the tank using a magnet. On ce the particles are removed, the contaminants can either be left on t he loaded particles and added to the glass feed slurry or stripped int o a small volume of solution so that the extracting particles can be r eused. The status of the chemistry and separation process is discussed in this paper.