The invention discloses a production technology for an 
autoclaved aerated concrete building block. The production technology is characterized in that the material formula comprises, by weight, 65% of 
fly ash, 15% of 
cement, 14% of 
lime, 5.5% of 
phosphogypsum and 0.5% of aluminum 
powder. The production technology comprises the following steps: firstly, slurries are prepared, namely, 
fly ash is ground by utilization of a ball 
grinding mill to prepare a 
fly ash slurry, 
phosphogypsum is added with water, then stirring is carried out for 1h, a 
phosphogypsum slurry is prepared, and then 
lime is crushed and ground to 
lime powder by utilization of the ball 
grinding mill; secondly, blending and stirring are carried out, namely, all the materials are sent to a 
casting mixer, the 
casting mixer is started, stirring is carried out and a concrete 
slurry is obtained; thirdly, 
casting and die entering are carried out, namely, all the concrete slurry in the casting mixer is placed in a die, and casting is carried out; fourthly, namely, a 
green body is thickened and condensed gradually; fifthly, 
cutting is carried out, namely, the shaped 
green body is 
cut according to a designed size; sixthly, autoclaved curing is carried out, namely, the 
cut green body is sent to an autoclaved curing kettle for autoclaved curing, and a finished product aerated concrete building block is obtained.