Method of manufacturing solar-grade polysilicon ingot with relevant induction apparatus

A method of manufacturing solar-grade polysilicon ingot with relevant induction apparatus comprising:

• charging raw silicon materials or liquidized silicon into an induction furnace for melting said raw materials into raw silicon water or heating said liquidized silicon;
• arranging a certain amount of solar-grade silicon slag removal into said furnace for mixing with said raw silicon water, thereby eliminating P-atomic(phosphorus) and other metal impurities inherent within said raw silicon materials;
• conducting some water vapor into said raw silicon water inside said furnace for a removal of B-atomic (boride), further attaining a pure silicon water;
• heating said pure silicon water in a water temperature range from 1500° C. to 1700° C.;
• predetermining an ingot casting crucible and a graphite mold disposed therein to be electrically heated in a temperature range between 1000° C. and 1400° C., then pouring said pure silicon water into said graphite molds;
• retaining said pure silicon water in said crucible for a while and controlling said water temperature range between 1450° C. and 1600° C.;
• adjusting said crucible and said mold to attain said temperature range from 1400° C. to 1430° C.;
• decreasing said temperature of said crucible and said molds gradient within 1000° C. to 1200° C., thereby generating a solid/liquid surface and interface property in said pure silicon water which would forward to a central of said mold;
• said metal impurities also concentrating on said central thereof;
• and then
• gradually reducing said temperature of said crucible for solidifying said pure silicon water into a crystallized ingot;
• further retaining said ingot inside said crucible in said temperature range from 1000° C. to 1200° C. until reaching said temperature in a range of 200° C. to 400° C., and thereafter taking said ingot out of said crucible for a natural-cooling, thus finishing an integral solar-grade polysilicon ingot.