Firstly, the dissolved mixed liquid in the mixed liquid tank is supplied to the filter cloth filter to start filtration. At this time, the filtrate returns to the above mixed liquid tank for circulation.
If a filter cake with the required thickness is formed on the filter cloth of the filter cloth filter, the filtrate does not return to the mixed liquid tank but flows through the discharge path for filtration.
After the filtration of the dissolved mixture is completed, pressurized air is supplied to one side of the filter cloth filter surface of the filter cloth filter, so as to dehydrate the filter cake formed on the filter cloth, then pure water is supplied to the mixture tank, and the filter cake on the filter cloth is cleaned by supplying the pure water of the mixture tank to the filter cloth filter.
Then, pressurized air is supplied to the opposite side of the filter cloth filter surface of the filter cloth filter to make the filter cake on the filter cloth fall off, so as to obtain monocrystalline silicon particles.
