In the previous article, we introduced the process flow of the aerated concrete block production line. Today, I will talk about the production process of the aerated board production line, hoping to be helpful to everyone.

According to B06 grade aerated concrete board (bulk density 600KG/m3), its design mix ratio (calculated by mass): water-cement ratio: 0.6. Sand: 70%, quicklime: 18%, cement: 10%, gypsum: 2%, aluminum powder 500 g/m3

Production Process:

a. Sand enters the feed bin, and after the lime and gypsum are crushed and ball-milled, when the fineness of the mixture reaches 3500-4000cm2/g, it is lifted to the ash storage bin by a bucket elevator for standby. The raw material handling and main dust prevention points are equipped with advanced pulse dust removal equipment to ensure compliance with the "Comprehensive Emission Standard for Atmospheric Pollutants" GB16297-3012.

b. Rebar processing: This is a unique process for producing aerated concrete boards, including rust removal, straightening, cutting, welding, coating preparation, coating immersion, and drying. Rebar is the structural material for producing aerated concrete boards, and process control not only affects product quality but also directly impacts the structural performance and safety of buildings.

c. Rebar mesh assembly: The rebar mesh assembly process involves assembling the anti-corrosion treated rebar mesh according to the required dimensions and relative positions, which is then placed into the mold after pouring is completed and fixed.

d. Ingredient mixing: The mortar, lime powder, and cement are each measured and added in sequence to the pouring mixer for mixing. During mixing, a certain amount of steam is introduced into the mixer according to process requirements, raising the slurry temperature to about 40-45℃. The mixing time is about 2-3 minutes, and the aluminum powder metering system performs a series of operations such as aluminum powder storage, metering, and slurry preparation to create an aluminum powder suspension for standby. Before discharging the slurry, the lower valve of the aluminum powder mixer is opened to allow the aluminum powder suspension to flow into the pouring mixer for mixing, with a mixing time not exceeding 40 seconds, and then the slurry is poured into the mold. The entire cycle takes about 4 minutes, and the whole system is centrally controlled by a computer to achieve precise automatic control of the ingredients, enabling remote operation and fault diagnosis.

e. After pouring is completed, the mold is treated with a bubble remover, and then transferred to the static curing area by a frequency conversion ferry for initial setting, with a curing temperature of about 40-45℃. The mold box is pulled by friction wheels to ensure smooth operation to the curing room. The pre-curing temperature of the entire static curing room can be automatically controlled, with a static time of 90-130 minutes. After reaching the cutting strength, it is pulled out of the static curing room.

f. The blank is placed on the cutting cart using a flipping hoist. The cart processes the blank through longitudinal cutting, grooving, and die cutting to achieve six-sided cutting of the blank, reaching the corresponding specification size (size error within ±1mm). After cutting, the blank is hoisted to the peeling device to recover the bottom waste. Then, the semi-finished product hoist lifts the blank along with the side plates to the steam curing cart for grouping. The cutting machine has high rigidity, does not deform, has high equipment precision, and good wear resistance, ensuring the cutting precision of the product for a long time. The wastewater and waste generated during the production process are recovered by the waste recovery system and remixed with new slurry for reuse. All waste from the entire cutting process is fully recovered.

g. In cold conditions, a pre-curing kiln is added in front of the autoclave to ensure that the blank is not affected by the low-temperature environment during grouping, while also appropriately reducing the steam curing cycle.

h. The blank enters the autoclave for steam curing, with a curing time of about 8-10 hours. During the entire steam curing process, the autoclave generates a large amount of residual steam and condensate. The design plan for the entire production line fully utilizes the residual steam and condensate discharged from the autoclave. The residual steam generated by the autoclave can mainly be used to preheat the products and the autoclave body temperature, and the remaining residual steam can be used as a heat source for the static curing room and slurry heating. In cold regions, it can also be used for heating. The condensate produced by the autoclave, due to containing harmful substances and irritating odors, cannot be used directly for living purposes, but its residual heat can be used to heat production and domestic water through a heat exchanger, while the condensate can be used for ingredient mixing and wet grinding processes, saving water and protecting the environment.

i. After steam curing is completed, the blanks are stacked and automatically packaged. The separated molds are transported by carts to the molding area for cleaning and oiling before being reused.