Xing Zhe

Uranium extraction from simulated salt lake water by an amidoxime-based UHMWPE fiber

A batch of amidoxime (AO)-based ultra-high molecular weight polyethylene (UHMWPE- g -(PAO-co-PAA)) fiber was prepared by a 7 L graft polymerization reaction kettle. The chemical structure and morphology were evaluated by means of Fourier transform infrared spectrometry and scanning electron microscope, respectively. The uranium adsorption behaviors of the UHMWPE- g -(PAO-co-PAA) fiber were studied by batch adsorption in simulated salt lake water. Effect of the total dissolved solids (TDS) and initial concentration of uranium on the adsorption behaviors of the fiber was investigated. It was found that after 28 d adsorption in the simulated DagzeCo salt lake water, UHMWPE- g -(PAO-co-PAA) fiber with an AO density of 6.0 mmol g−1 exhibited a uranium adsorption capacity of 8.29 mg g−1. The adsorption capacity decreased with the increment of TDS. In the simulated salt lake water in which TDS was 10 times as the sea water, the adsorption capacity of uranium was 6.63 mg g−1. The adsorption capacity increased with the increment of initial concentration of uranium in solution. The uranium adsorption capacity was 4.54 mg g−1 in a solution with initial concentration of 187 µg L−1 uranium, while the value increased to 17.48 mg g−1 with 1639 µg L−1 uranium simulated salt lake water solution. This study should shed light on improvement of uranium extraction from salt lake water and further application in uranium recovery from natural resources.

Strike Point Control on EAST Using an Isoflux Control Method

For the advanced tokamak, the particle deposition and thermal load on the divertor is a big challenge. By moving the strike points on divertor target plates, the position of particle deposition and thermal load can be shifted. We could adjust the Poloidal Field (PF) coil current to achieve the strike point position feedback control. Using isoflux control method, the strike point position can be controlled by controlling the X point position. On the basis of experimental data, we establish relational expressions between X point position and strike point position. Benchmark experiments are carried out to validate the correctness and robustness of the control methods. The strike point position is successfully controlled following our command in the EAST operation.