Cross-flow filtration is a pressure-driven separation process,
commonly recognized as an efficient fluid management technique.
The membrane washing setup of Changcheng Xinyuan
Membrane Technology Corporation, Hefei, China, was used to
wash nano-sized powder precursors, as shown in Fig. 3. Slurries
of nanometer ceramic powder precursors were washed by the
concentrating–diluting method: the slurries were first concentrated
up to one third of their original volumes via permeation
through the membrane, and then diluted back to their original
volumes by adding water. The concentration of salt was reduced
with increasing washing times. Many parameters influence washing
efficiency, which were determined by permeation flow. These
parameters include filtration conditions such as the transmembrane
pressure, cross-flow velocity and solid concentration of the
slurry