METHOD FOR DECONTAMINATING SOLUTIONS AND/OR PULPS WITH HIGH CONTENT OF NATURAL RADIONUCLIDES Russian patent published in 2003 - IPC

FIELD: chemical technology; neutralizing and decontaminating radioactive solutions and waste water. SUBSTANCE: method intended for neutralizing and decontaminating radioactive solutions and/or pulps contaminated with Th-232 and daughter products of its decay (Ra-228, Ra-224) in amounts exceeding those specified by NRB and OSPRB, as well as with rare-earth elements, Sc, Fe, Cr, Mn, Al, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, etc. includes their treatment with barium chloride, sodium sulfate and hydroxide followed by separation of radioactive fall-outs from solution and their disposal; source solution and/or pulp is first treated with sodium hydroxide solution to pH 8.5-9.5 whereupon barium chloride and sodium sulfate solution is introduced in the amount of 1.3-2 moles of Na₂SO₄ per 1 mole of BaCl₂; then hydrate-sulfate pulp is mixed up with iron chloride solution (III) in the amount of 0.3-0.8 mole of FeCl₃ per 1 mole of Na₂SO₄. Proposed treatment ensures enhanced degree of joint precipitation of natural radionuclides of Th-232 range and radioactive sediments fall-outs or cakes. EFFECT: reduced radioactivity of effluents upon separation of radioactive cakes. 5 cl