Method of obtaining pure silicon by fractional crystallization

Claim 1

A METHOD OF OBTAINING PURE SILICON BY FACTIONAL CRYSTALLIZATION, COMPRISING FORMING A SILICON-ALUMIUM ALLOY BY DISOLVING IMPURE SILICON IN AN ALUMINUM BASE ALLOY AT A TEMPERATURE OF ABOUT 30* TO 50*C. HIGHER THAN SILICON-ALUMINUM ALLOY WITH 1 TO 2% OF ITS WEIGHT OF A FLUX CONTAINING 80% OF SODIUM CHLORIDE AND 20% OF A MEMBER OF THE GROUP CONSISTING OF SODIUM FLUORIDE AND CRYOLITE TO REMOVE OXYGEN, CARBON, AND PHOSPHORUS PRESENT IN SAID SILICON-ALUMINUM ALLOY, THEREBY FORMING DROSS, REMOVING THE DROSS, COOLING SAID LIQUID SILICON-ALUMINUM ALLOY AT A RATE NOT GREATER THAN ABOUT 30*C. PER HOUR, FOLLOWING A LAW REPRESENTED BY THE EQUATION T=KTN, WHERE T IS THE FALL IN TEMPERATURE IN *C. BELOW THE POINT OF SOLIDIFICATION OF SAID ALLOY, T IS THE TIME HOURS, N IS 1 OR 3, AND K IS A CONSTANT HAVING A VALUE NOT GREATER THAN ABOUT 30 BUT GREATER THAN 0 WHEN N IS 3, UNTIL A SPONGE OF LARGE CRYSTALS IS FORMED IN A MOTHER LIQUID CONTAINING IMPURITIES, DRAWING OFF THE GREATER PART OF THE MOTHER LIQUID FROM THE SPONGE BEFORE COMPLETE SOLIDIFICATION OF SAID SILICONALUMINUM ALLOY, DRAINING MOTHER LIQUID FROM THE SPONGE AND TREATING THE SPONGE TO REMOVE IMPURITIES DEPOSITED DURING COOLING OF SAID SILICON-ALUMINUM ALLOY, AND COLLECTING THE PURE SILICON THUS OBTAINED.

Claim 2

A METHOD OF OBTAINING PURE SILICON BY FACTIONAL CRYSTALLIZATION, COMPRISING FORMING A SILICON-ALUMIUM ALLOY BY DISOLVING IMPURE SILICON IN AN ALUMINUM BASE ALLOY AT A TEMPERATURE OF ABOUT 30* TO 50*C. HIGHER THAN SILICON-ALUMINUM ALLOY WITH 1 TO 2% OF ITS WEIGHT OF A FLUX CONTAINING 80% OF SODIUM CHLORIDE AND 20% OF A MEMBER OF THE GROUP CONSISTING OF SODIUM FLUORIDE AND CRYOLITE TO REMOVE OXYGEN, CARBON, AND PHOSPHORUS PRESENT IN SAID SILICON-ALUMINUM ALLOY, THEREBY FORMING DROSS, REMOVING THE DROSS, COOLING SAID LIQUID SILICON-ALUMINUM ALLOY AT A RATE NOT GREATER THAN ABOUT 30*C. PER HOUR, FOLLOWING A LAW REPRESENTED BY THE EQUATION T=KTN, WHERE T IS THE FALL IN TEMPERATURE IN *C. BELOW THE POINT OF SOLIDIFICATION OF SAID ALLOY, T IS THE TIME HOURS, N IS 1 OR 3, AND K IS A CONSTANT HAVING A VALUE NOT GREATER THAN ABOUT 30 BUT GREATER THAN 0 WHEN N IS 3, UNTIL A SPONGE OF LARGE CRYSTALS IS FORMED IN A MOTHER LIQUID CONTAINING IMPURITIES, DRAWING OFF THE GREATER PART OF THE MOTHER LIQUID FROM THE SPONGE BEFORE COMPLETE SOLIDIFICATION OF SAID SILICONALUMINUM ALLOY, DRAINING MOTHER LIQUID FROM THE SPONGE AND TREATING THE SPONGE TO REMOVE IMPURITIES DEPOSITED DURING COOLING OF SAID SILICON-ALUMINUM ALLOY, AND COLLECTING THE PURE SILICON THUS OBTAINED.