Fly ash AAC block is made of lightweight porous silicate products made of cement, lime and fly ash as the main raw materials and adding air generating agent (aluminum powder) through batching, mixing, pouring, pre-curing, cutting, autoclaving and packing. It contains a large number of uniform and small pores after gas, so the name of aerated concrete.
Fly ash AAC block formula
Fly ash AAC block typical raw material formula and consumption: fly ash: content ratio 70%; Consumption per cubic meter: 350kg; Cement: 13.8%; Consumption per cubic meter: 25-30kg; Lime: 13.8%; Consumption per cubic meter: 140-150kg; Phosphogypsum: 2.96%; Consumption per cubic meter: 15kg; Aluminum powder: trace content; Consumption per cubic meter: 0.4kg.
Fly ash is the core raw material of this product and also the main source of silicon aluminum composition of aerated concrete. Shall comply with (JC409-91) standards.
Production technology of fly ash AAC block
AAC block machine can be produced by different processes according to the categories of raw materials, quality and process characteristics of the main equipment. But in general, fly ash and water into slurry, adding powdered lime, cement, gypsum and foaming agent, after classics agitate injection mould box, static oxygen foaming after curing, cutting into various specifications block or plate, the steam car ownership into autoclave, under the high temperature of saturated steam curing the formation of porous lightweight aerated concrete products.
1. AAC block raw material processing
Fly ash is sent to the ball mill by electromagnetic vibration feeder and belt conveyor, and the pulverized fly ash is sent to the slurry tank for storage by fly ash pump respectively.
The lime is sent into the jaw crusher by the electromagnetic vibration feeder and belt conveyor for crushing. The crushed lime is sent into the lime storage bin by the bucket elevator, and then into the ball mill by the screw conveyor. The finely ground material is sent into the powder distribution bin by the screw conveyor and bucket elevator. The chemical is measured manually in a certain proportion and then the solution of a certain concentration is sent to the storage tank for storage.
2. AAC block raw material storage and feeding
Raw materials are transported into the factory by car, and fly ash is concentrated in the raw material field, which is loaded into the hopper when used. Bagged or bulk cement is stored in the cement store. Use loading hopper when in use. Chemicals and aluminum powder are put in chemical warehouse and aluminum powder warehouse respectively, and shipped to the production workshop respectively when used.
3. AAC block batching, stirring and pouring
Lime and cement are successively sent to the automatic measuring scale by the screw conveyor under the powder mixing bin for cumulative measurement. The screw conveyor under the scale can evenly add materials into the pouring mixer.
Fly ash and waste slurry are put into the measuring cylinder for measurement, and the slurry can be stirred when the mold is in place after the measurement of various materials. The slurry should meet the technological requirements (about 40℃) before pouring. If the temperature is not enough, the slurry can be heated by steam in the slurry measuring tank, and aluminum powder suspension can be added 0.5 ~ 1 minutes before pouring.
4. Primary feeding and cutting of AAC block
After casting, the mold is pushed into the primary incubator with a conveyor chain for gas generation and initial coagulation at room temperature of 50 ~ 70℃ and initial incubation time of 1.5-2 hours (this process can be exempted according to geographical favorable conditions). After initial incubation, the mold frame and the blank body are hung together with the negative pressure hanger to the cutting table where the bottom plate of the kettle is placed in advance. Remove the mold frame. The cutting machine is transverse cutting, longitudinal cutting, milling bread head, mold frame hanging back to the mold truck manual cleaning and degreasing, and then hanging to the mold car group mold for the next casting, cut the body together with the bottom plate of the kettle with the crane to the kettle car on two layers, there are four layers of support, several kettle car into a group.
The waste from the edges and corners of the body produced when cutting is sent to the waste pulp stirring machine next to the cutting machine by the screw conveyor, which is made into waste pulp with water and used when batching.
5. Autoclaving and finished products
After the body is assembled on the parking line in front of the autoclave, open the autoclave door to be discharged from the autoclave, first pull the finished autoclave car out of the autoclave with a winch, and then pull the autoclave car into the autoclave for maintenance with a winch. The finished products on the kettle car are lifted to the finished product warehouse by bridge crane, and then transported to the finished product yard by fork loader. The empty kettle car and the bottom plate of the kettle are lifted back to the carriage return line, and then pulled back to the code rack by winch for the next cycle.
