NOVELTY - Purifying silicon comprises: (1) preparing a mixed melt by silicon, a fluxing agent and an impurity removal agent, where the fluxing agent is e.g. lithium, potassium, barium, and strontium, and the impurity removal agent is e.g. potassium, barium, strontium, and calcium, (2) optionally refining or purifying the mixed melt; (3) crystallizing the silicon and separating from the mixed melt; and (4) optionally removing the residual components in the fluxing agent in the silicon crystal.    USE - The method is useful for removing boron or phosphorus impurities (claimed), and in the field of semiconductors and the electronic; and for the manufacture of solar battery sheet, preferably crystal silicon battery sheet.    ADVANTAGE - The method: provides the silicon with high purity, and with less energy consumption; and is devoid of toxic factors, inexpensive, and simple process.    DETAILED DESCRIPTION - Method of purifying silicon comprises: (1) preparing a mixed melt by silicon, a fluxing agent and an impurity removal agent, where the fluxing agent is substances or a compound of more than one substance such as lithium, potassium, barium, strontium, calcium, sodium, lanthanum, cerium, neodymium, samarium, terbium, gadolinium, terbium, yttrium, magnesium, palladium, scandium, beryllium, aluminum, titanium, manganese, zinc, chromium, gallium, iron, cadmium, indium, thallium, cobalt, nickel, platinum, tin, thulium, lead, bismuth, copper, silver and gold, the impurity removal agent is a simple substance containing potassium, barium, strontium, calcium, sodium, lanthanum, cerium, neodymium, samarium, terbium, gadolinium, terbium, yttrium, magnesium, palladium, scandium, beryllium, aluminum, titanium, zirconium, vanadium, manganese, niobium, zinc, chromium, iron, cadmium, indium, cobalt and nickel; (2) optionally refining or purifying the mixed melt; (3) crystallizing the silicon and separating from the mixed melt; and (4) optionally removing the residual components in the fluxing agent in the silicon crystal. An INDEPENDENT CLAIM is included for a method for removing boron impurities or phosphorus impurities in silicon, comprising preparing the mixed melt, optionally refining or purifying the mixed melt; crystallizing the silicon and separating from the mixed melt; and optionally removing the residual components in the fluxing agent in the silicon crystal.