Aluminum pretreatment alkaline three-in-one, alkaline liquor regeneration and aluminum hydroxide online recycling process

The invention provides an aluminum pretreatment alkaline three-in-one, alkaline liquor regeneration and aluminum hydroxide online recycling process. A medicament recycling system and two flowing washing tanks are included. The medicament recycling system comprises an alkaline three-in-one grinding tank and a non-flowing washing tank sub system; the a non-flowing washing tank sub system is arranged to be in reverse series-connection with the alkaline three-in-one grinding tank through a first valve; the non-flowing washing tank sub system comprises a first non-flowing washing tank body and a second non-flowing washing tank body which are arranged to be in reverse series-connection with each other, and the start end of the second non-flowing washing tank body is furthermore provided with a water supplementing opening and a third valve in the water flowing direction; and the two flowing washing tanks are arranged to be in reverse series-connection, the start end is provided with a water inlet in the water flowin