Preparation method of refining agent for melting aluminum alloy section doped with plant ash

The invention discloses a preparation method of a refining agent for melting an aluminum alloy section doped with plant ash. The refining agent is prepared from the following materials in parts by weight of 6-8 parts of potassium chloride, 4-6 parts of wood ash coated particles, 3-5 parts of calcium fluoride, 3-5 parts of sodium nitrate, 5-8 parts of graphite powder, 8-10 parts of sodium fluorosilicate, 3-5 parts of sodium sulfate, 5-8 parts of aluminum chloride, 3-5 parts of potassium carbonate, 8-10 parts of attapulgite, 5-8 parts of NaBF4, 3-5 parts of sodium chloride, 5-8 parts of potassium sulphate, 8-10 parts of Na2TiF6, and 5-8 parts of NaF. High-quality aluminum alloy melting liquid is obtained by treatment of the refining agent. Therefore, the aluminum alloy melting liquid is used for casting production; the yield is obviously improved; especially the porosity in a cast is reduced by 1-2 degrees; effective control is carried out; an air hole is not generated at the surface of the cast; trapped oxide is obviously reduced; and oxide inclusion is at about two grades while the mechanical property of the cast is obviously improved.