Cellular silicate blocks, made by adding aluminum powder as an aerating agent to a mixture of calcium-based materials (such as cement, lime) and siliceous materials (such as fly ash, slag), followed by water mixing, casting, gas inflation, pre-curing cutting, and then high-pressure steam curing.
The process of manufacturing Yanzhou autoclaved aerated concrete blocks:
1. The raw materials for aerated block storage and supply are transported to the factory by truck. Fly ash (or sand, stone powder) is concentrated at the raw material site, and is loaded into hoppers as needed. Bagged cement or bulk cement is stored in the cement warehouse. It is loaded into hoppers as required. Chemicals, aluminum powder, and other materials are stored separately in the chemical and aluminum powder warehouses, and are transported to the production workshop as needed.
2. Aggregates raw materials, processed through a ball mill for fly ash (or sand, stone powder), then fed into the mill via an electromagnetic vibration feeder and a belt conveyor. The finely ground fly ash (or sand, stone powder) is separately sent to slurry tanks for storage. Lime is fed into a jaw crusher via an electromagnetic vibration feeder and a belt conveyor for crushing. The crushed lime is then lifted into a lime storage bin via a bucket elevator, followed by a screw conveyor to the ball mill. The finely milled material is conveyed by a screw conveyor and bucket elevator to the powdered material blending storage. It is evident that the preparation of raw materials is crucial. Chemicals, measured by a certain ratio manually, are made into a solution of a specific concentration and stored in tanks. Aluminum powder is transported from the aluminum powder storage to the production workshop, lifted to the second floor of the blending building using an electric hoist, and then poured into a mixer with a predetermined amount of water, forming an aluminum powder suspension.
3. The components for aerated block production, including mixing, lime and cement pouring, are sequentially delivered to the automatic weighing scale for cumulative measurement by a spiral conveyor beneath the powder material storage bin. A spiral conveyor beneath the scale evenly adds the materials to the pouring mixer. Fly ash (or sand, stone powder) and waste slurry are measured in a measuring tank. After the measurement of various materials and the mold is in place, the slurry mixing can be initiated. The slurry should reach the process requirement (about 45℃) before pouring. If the temperature is insufficient, steam heating can be applied to the slurry measuring tank. The aluminum powder suspension can be added to the slurry 0.5 to 1 minute before the material is poured.
4. After curing and cutting, the mold is pushed into the curing room using a conveying chain for gas generation and initial setting. The room temperature is between 48-68°C, with an initial curing time of 1.5-2 hours (this process can be omitted depending on favorable geographical conditions). After curing, the mold and green body are lifted together using a vacuum lifting device onto a cutting table with pre-positioned bottom plates. The mold is removed, and the cutting machine performs transverse, longitudinal cuts, and milling of the bread ends. The mold is then lifted back onto a mold transport vehicle for manual cleaning and de-greasing before being placed on a mold vehicle for the next casting. The cut green bodies, along with the bottom plates, are lifted by crane onto the kettle vehicle, stacked in two layers with four supports between each layer. The kettle vehicles are grouped together. The waste edges and corners produced during cutting are transported to the waste slurry mixer next to the cutting machine via a spiral conveyor, mixed with water to form waste slurry for use during batching.
5. After the aerated blocks and finished坯bodies are assembled on the kiln's parking line, open the kiln door to be discharged. First, use the hoist to pull out the finished kiln car from inside, then use the hoist to pull the car to be autoclaved into the autoclave for curing. The finished products on the kiln car are lifted to the finished product warehouse using a bridge crane, then transported to the finished product storage area by forklifts. The empty kiln cars and kiln bottom plates are lifted back to the return track, cleaned, and then retracted to the storage racks using the hoist for the next cycle. The entire process is as described above. Compared to the autoclaved brick process, the process for aerated blocks is more complex. Additionally, the application range of aerated block products is broader than that of autoclaved bricks, and the price of aerated block products is slightly higher, mainly used in high-rise buildings.
