TW233312B - A recovery and stabilization process for secondary aluminum residue - Google Patents

Abstract

A recovery and stabilization process for secondary aluminum residue, whichcomprises the steps of: (a) wet ball milling; (b) wet sieving; (c) gasstripping to remove ammonia; (d) sedimentation of concentrated sludge,which is characterized in:ixing the secondary aluminum residue with waterat a ratio of 1:1 to 1:5 and feeding the mixture into a continuous or batchball mill to undergo ball milling in order to grind separation of thealuminum nitride, aluminum carbide and non-metal materials such as chloridesalt, in which the aluminum nitride and aluminum carbide will undergoreactions with water to separately generate methane and ammonia, the methanecan be introduced into an explosion-proof burner and the ammonia isdissolved in the water and can be stripped off by a gas stripping de-ammoniadevice, if the ammonia content is too high the stripping system can beadditionally added with dedicated air and the air circulates in a closedloop in which the ammonia in the air is washed and neutralized; during theball milling, the dissolved chloride salt including sodium chloride andpotassium chloride can be processed by the followed sedimentation ofconcentrated sludge tank, the precipitated clear liquid can be discharged byoverflow, therefore, the harmful materials such as aluminum nitride,aluminum carbide and chloride salt in the aluminum residue can be completelydissolved or removed to achieve stabilized processing and elevate thequality of recyclable aluminum in the residue to enable the aluminum to berecycled to the furnace.