Method for separating silicon-containing mixture to obtain industrial silicon

The invention relates to a method for separating a silicon-containing mixture to obtain industrial silicon. The method comprises the following steps: (1) putting a liquid silicon-containing mixture metal with a temperature of 900-2500 DEG C into a heat preservation bag; (2) controlling the cooling speed of the liquid silicon-containing mixture metal, and allowing silicon crystals to be separated out and grow; (3) filtering grown solid industrial silicon by using a filtering device of crystalline silicon or a micropore filter screen so as to obtain the industrial silicon; and (4) after the industrial silicon is filtered out, fully separating liquid-phase elements out of a residual liquid mixture by throwing or pressing so as to obtain an alloy byproduct. According to the invention, a mixture liquid-phase segregation purification principle is utilized; silicon crystals are separated out firstly during cooling; solid-phase and liquid-phase substances are separated by utilizing a supergravity effect generated by