TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method for purifying silicon involves: i) forming a first molten liquid from a source silicon and the solvent metal; ii) contacting the first molten liquid with a first gas, to provide dross and a second molten liquid; iii) separating the dross and the second molten liquid; iv) cooling the second molten liquid to form first silicon crystals and a first mother liquor; v) separating the first silicon crystals and the first mother liquor; vi) contacting the first silicon crystals with an acid, base, alcohol or chemical capable of dissolving the solvent metal, to provide washed silicon crystals and used acid; and vii) separating the washed silicon crystals and the used acid; and the method further involves before forming the first molten liquid, pre-treating source silicon by slagging, gas injection, plasma torch and/or vacuum treatment; before forming the first molten liquid, adding titanium, vanadium, chromium, zirconium, calcium, hafnium, magnesium and/or strontium to the source silicon; filtering the second molten liquid; processing the washed crystals sufficient to provide solar cells, solar panels, wafers or integrated circuits; and purifying the washed silicon crystals to provide solar grade silicon that is mixed with other silicon to provide solar panel grade silicon. Contacting with the first gas provides small bubbles. In step (i) and step (A), the first molten liquid is formed by heating above the liquidus temperature. In step (i) and step (A), metallurgical grade silicon is employed with a phosphorus level below 60 parts per million weight (ppmw) and boron level below 15 ppmw; silicon is employed in 20-60 wt.%; and aluminum, or its alloy, is employed as the solvent metal, in 40-80 wt.%. The step (ii) is carried out while agitating the first molten liquid, or employing a rotary degasser. After step (i) and before step (ii), the first molten liquid is cooled to below the liquidus temperature or to slightly above the liquidus temperature. In step (iii), the dross is removed from the surface of the second molten liquid; and after step (iii), the second molten liquid is transferred to a second vessel. In step (iv) and step (B), the second molten liquid is cooled to above the solidus temperature and below the liquidus temperature, and step (iv) is carried out while agitating the second molten liquid. The step (v) and step (C) is carried out by pouring off the first mother liquid from the first silicon crystals. After step (v) and before step (vi), repeating steps (i)-(v). After step (v) and before step (vi), repeating steps (i), (iii), (iv) and (v). The separating in step (vii) is carried out employing a strainer. At least one of step (i)-(vii) is carried out multiple times, and each of step (i)-(vii) is independently carried out multiple times. The first silicon crystals comprise silicon (85-98 or 85-99 wt.%). The washed silicon crystals comprise aluminum 800-2000 (preferably 500-2000) ppmw. The processing the washed silicon crystals involves at least one of: vacuum treatment, slag treatment, gas injection, with at least one of oxygen, water, hydrogen and argon; directional solidification, and employing the washed silicon crystals as feedstock for a silane/Siemen's gas process. The aluminum is contacted with the first silicon crystals, and melted to provide a subsequent second molten liquid. The separating in step (E) is carried out employing a strainer. At least one of step (A)-(E) is carried out multiple times, each of step (A)-(E) is independently carried out multiple times. The method for purifying silicon, involves: forming a first molten liquid from source silicon and aluminum; contacting the first molten liquid with a first gas, to provide dross and a second molten liquid; separating the dross and the second molten liquid; cooling the second molten liquid to form first silicon crystals and a first mother liquor; separating the first silicon crystals and the first mother liquor; optionally melting the first silicon crystals with a solvent metal and repeating the forming, contacting, separating, cooling, and separating steps; contacting the first silicon crystals with an acid, base, alcohol or chemical capable of dissolving the solvent metal, to provide washed silicon crystals and used acid; and separating the washed silicon crystals and the used acid, sufficient to provide purified silicon crystals; melting the purified silicon crystals, sufficient to provide a silicon melt; contacting the silicon melt with a second gas; and directionally solidifying the silicon melt, where an ingot is produced; and further involves removing the top of the ingot, where removing involves pouring off the top of a partially molten ingot; directionally solidifying the ingot or boule sufficient to form a multicrystalline ingot or monocrystalline boule; filtering the second molten liquid; and filtering the silicon melt. The washed silicon crystals includes phosphorus less than about 15 (preferably less than about 9, especially less than about 4) ppmw, and boron less than about 5 (preferably less than about 3, especially less than about 2) ppmw. Preferred Components: The second gas comprises oxygen or a mix of oxygen and an inert gas. The first gas comprises chlorine or a mix of chlorine and an inert gas. EXAMPLE - A mixture (950 lb) of 40% metallurgical Silicon and 60% primary aluminum was melted and heated to 975 degrees C in a furnace. Calcium (0.25 lb) was added to the melt by using an aluminum-calcium master alloy. The dross was skimmed off the surface of the melt. The temperature was lowered to 950 degrees C and N2 (85%) and Cl2 (15%) gas was injected into the molten mixture for 3 hrs through a rotary degasser followed by N2 gas (100%) for 15 minutes. The dross was skimmed off of the surface of the melt every 30 minutes. The mixture was heated up to 1000 degrees C. The molten mixture was poured into a new furnace and the temperature was lowered over 8 hrs to 750 degrees C. The molten mother liquor was then poured out of the furnace and the remaining silicon crystals/flakes were raked out of the furnace. The silicon flakes/crystals were then melted with aluminum in a 50-50 wt.% ratio in a furnace. The gas injection, dross removal and crystal growing procedure were repeated. The flakes were then placed in a solution of HCl+water (8 wt.%) and the aluminum was dissolved off of the flakes for 72 hrs. The flakes were then strained from the acid and dried. The dried flakes where then melted in a furnace. Once melted, O2 (99.5%) was injected into the molten silicon through a lance for 3 hrs. The dross or slag was skimmed off the furnace and the molten silicon was poured into a furnace that directionally solidified the silicon from the bottom up. The top of the silicon ingot was cut off and the remainder of the silicon was melted in a furnace to give the silicon a directional solidification. The resulting polysilicon had a Boron level of 0.79-1.1 parts per million weight (ppmw) and phosphorus level of 0.27-1.1 ppmw with other metals below 1 ppmw.