Uranium control in phosphogypsum. [In wet-process phosphoric acid production]

Conference · Tue Jan 01 00:00:00 EST 1980

OSTI ID:5914355

Hurst, F J; Arnold, W D

In wet-process phosphoric acid plants, both previous and recent test results show that uranium dissolution from phosphate rock is significantly higher when the rock is acidulated under oxidizing conditions than under reducing conditions. Excess sulfate and excess fluoride further enhance the distribution of uranium to the cake. Apparently the U(IV) present in the crystal lattice of the apatite plus that formed by reduction of U(IV) by FE(II) during acidulation is trapped or carried into the crystal lattice of the calcium sulfate crystals as they form and grow. The amount of uranium that distributes to hemihydrate filter cake is up to seven times higher than the amount that distributes to the dihydrate cake. About 60% of the uranium in hemihydrate cakes can be readily leached after hydration of the cake, but the residual uranium (20 to 30%) is very difficult to remove economically. Much additional research is needed to develop methods for minimizing uranium losses to calcium filter cakes.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5914355
• Report Number(s): CONF-801161-2; ON: DE82004096; TRN: 82-000116
• Resource Relation: Conference: International symposium on phosphogypsum, Lake Buena Vista, FL, USA, 5 Nov 1980
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
PHOSPHATE ROCKS
ORE PROCESSING
PHOSPHORIC ACID
PRODUCTION
URANIUM
REMOVAL
APATITES
DISSOLUTION
FLUORIDES
GYPSUM
SULFATES
ACTINIDES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM SULFATES
ELEMENTS
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
METALS
MINERALS
OXYGEN COMPOUNDS
PROCESSING
ROCKS
SEDIMENTARY ROCKS
SULFUR COMPOUNDS
050400* - Nuclear Fuels- Feed Processing