Abstract: In order to reduce the accumulation of phosphogypsum ( PG) and sulfur-fixing ash ( SFA) in the environment,avoid the risks to the natural environment and minimize the environmental pollution,a new composite adsorption material of phosphogypsum / sulfur-fixing ash ( PG / SFA) was prepared by one-step high-temperature calcination method with PG and SFA as raw materials,and the uranium [ U( Ⅵ )] of PG / SFA was studied by batch static adsorption method. Based on the strong U(Ⅵ ) affinity of PG / SFA,the deep purification treatment of uranium mine water produced in the process of U( Ⅵ ) mining was studied. Finally,the adsorption mechanism of PG / SFA for U( Ⅵ ) was discussed by means of SEM,FTIR and XRD. The results show that the adsorption capacity of PG / SFA for U(Ⅵ) can reach 84. 6 mg / g under the conditions of pH of 6. 0,PG / SFA adsorbent dosage of 0. 02 g,adsorption time of 60 min,initial concentration of U(Ⅵ) of 125 mg / L and adsorption temperature of 40 ℃ . The adsorption of U(Ⅵ) by PG / SFA accords with pseudo-second-order kinetic model and Langmuir isothermal adsorption model. The coexistence of anions and cations (Ba2+,Sr2+,Ni2+,Ca2+,Cl-,NO- 3 ,CO23-,F- ) in water has little effect on the U(Ⅵ) adsorption performance of PG / SFA. In real uranium mine water,the removal rate of U(Ⅵ ) by PG / SFA can reach 99. 8%,the distribution coefficient (Kd) is as high as 1. 46×106 mL / g,and the effluent U(Ⅵ ) concentration is as low as 0. 003 mg / L. The adsorption mechanism of U(Ⅵ) by PG / SFA is mainly that Ca2+ and PO34- in PG / SFA react with UO2+ 2 by precipitation,and then autunite Ca( UO2 )2( PO4 )2· 3H2O mineral phase structure is formed on the surface of PG / SFA. Therefore,the utilization of industrial solid waste phosphogypsum and sulfur-fixing ash can be used as efficient adsorption materials for uranium mine water,thus achieving the goal of " treating waste with waste" .

Key words: phosphogypsum,sulfur-fixing ash,adsorption,uranium mine water,treat waste with waste