A method for changing solidifying
crucible bottom layering manner in
electron beam
polycrystalline silicon purification belongs to the field of
electron-beam melting and comprises the following steps: layering 3 Kg of
polycrystalline silicon wafers (with thickness of 7-10 mm) at the bottom of a solidifying
crucible, and layering 5 Kg of
polycrystalline silicon fragments on the polycrystalline
silicon wafers; preheating
electron guns; gradually increasing the power of an
electron gun for irradiating a
smelting crucible to 250 KW and the power of an
electron gun for irradiating the solidifying crucible to 50 KW, and melting
silicon; increasing the power of the
electron gun for irradiating the solidifying crucible to 200 KW, and melting
silicon; turning off the electron gun for irradiating the
smelting crucible, outpouring silicon liquid, and increasing the power of the electron gun for irradiating the solidifying crucible to 250 KW; increasing the power of the electron gun for irradiating the
smelting crucible to 250 KW, and melting and smelting silicon; and turning off the electron gun for irradiating the smelting crucible, outpouring silicon liquid, turning on the electron gun, keeping the power at 250 KW for 10 min, keeping the power at 200 KW for 2 min, keeping the power at 150 KW for 3 min, keeping the power at 120 KW for 5 min, keeping the power at 100 KW for 7 min, keeping the power at 80 KW for 8 min, keeping the power at 50 KW for 12 min, keeping the power at 30 KW for 16 min, keeping the power at 20 KW for 20 min, decreasing the power to 0 KW, and reducing the electron beam for solidifying. The method disclosed by the invention can increase product yield, and reduce the
energy consumption of electron beam polycrystalline silicon purification.