AAC Production Process: 8 Key Manufacturing Steps

The AAC production process transforms sand or fly ash, cement, lime, gypsum, water and aluminum powder into lightweight autoclaved aerated concrete blocks or panels. Accurate batching, stable temperature control, precision cutting and proper autoclave curing are essential for achieving consistent product quality.

HUAZHU supplies complete AAC block and AAC panel production lines with annual capacities from 50,000 to 500,000 m³/year. We customize each production line according to the customer’s raw materials, required capacity, product specifications, available land and automation requirements.

Main Raw Materials for AAC Production

The raw material formula varies according to local availability and laboratory test results. A typical AAC plant uses the following materials:

• Siliceous material: sand, fly ash or other suitable silica-rich material
• Cement: provides strength and participates in the hydration reaction
• Lime: supplies calcium oxide for the hydrothermal reaction
• Gypsum: regulates the reaction and improves product performance
• Water: used for slurry preparation, mixing and process control
• Aluminum powder or paste: acts as the aerating agent and creates the cellular structure

Before finalizing the equipment configuration and production formula, HUAZHU recommends testing the customer’s raw materials to confirm their chemical composition, fineness and suitability for AAC manufacturing.

Complete AAC Block Manufacturing Process

Step 1: Raw Material Preparation

Sand is crushed and ground in a ball mill with water to produce slurry. When fly ash is used, it may be mixed directly with water and stored in a slurry tank. Lime is crushed and ground to the required fineness, while cement and gypsum are stored separately.

Main equipment: jaw crusher, ball mill, bucket elevator, lime silo, cement silo, slurry tank and slurry agitator.

Step 2: Storage and Automatic Batching

Prepared raw materials are stored in silos and slurry tanks. The batching system weighs slurry, cement, lime, gypsum, water and aluminum powder according to the selected production formula.

Accurate weighing is important because variations in the formula can affect rising performance, cutting strength, density and final product quality.

Main equipment: material silos, screw conveyors, slurry pumps, weighing systems, aluminum powder preparation unit and PLC control system.

Step 3: Mixing and Pouring

The weighed materials are transferred into a high-speed mixer. After uniform mixing and temperature adjustment, the aluminum suspension is added. The mixture is then poured into an AAC mould.

The pouring temperature, mixing time and slurry consistency must be carefully controlled to ensure stable expansion and uniform pore distribution.

Main equipment: high-speed mixer, pouring machine, mould, side plate and ferry cart.

Step 4: Pre-curing and Cake Formation

After pouring, the mould is transferred to the pre-curing area. The aluminum reacts with alkaline materials and releases gas, causing the mixture to expand and form a porous structure.

During pre-curing, the cake gradually develops enough strength for demoulding and cutting. Temperature and curing time must remain stable to prevent collapse, cracking or insufficient hardness.

Main equipment: pre-curing room, mould transfer system and temperature-control equipment.

Step 5: Demoulding and Precision Cutting

When the cake reaches the required cutting strength, a tilting hoist turns the mould by 90 degrees and removes the mould frame. The green cake is then cut into the required block or panel dimensions.

The cutting system performs horizontal, vertical and cross cutting. Excess material can be collected and returned to the slurry preparation system, reducing raw material waste.

Main equipment: tilting hoist, demoulding device, vertical cutting machine, horizontal cutting machine, cross-cutting machine and waste-slurry recycling system.

Step 6: Grouping and Transfer to Autoclaves

After cutting, the cakes are grouped on autoclave trolleys and moved to the autoclave section. The transfer process must keep the green cakes stable and prevent deformation or damage.

Main equipment: grouping crane, autoclave trolley, ferry cart, transfer tracks and traction system.

Step 7: High-Pressure Autoclave Curing

The cut cakes are cured inside autoclaves using high-temperature, high-pressure steam. During this stage, calcium and silica react to form stable hydration products that provide AAC blocks and panels with their required strength and durability.

The exact pressure, temperature and curing cycle should be determined according to the raw material formula, product density and required strength.

Main equipment: autoclaves, steam piping system, valves, condensate system, boiler or other suitable steam source.

Step 8: Separating, Packaging and Storage

After autoclave curing, the finished products are removed from the autoclaves. The blocks are separated, inspected and transferred to the packaging line. Qualified products are stacked, strapped or wrapped and then moved to the finished-product storage area.

Main equipment: block separator, clamping machine, conveyor, palletizing system, strapping machine and finished-product crane.

AAC Process and Equipment Summary

Available AAC Production Line Capacities

HUAZHU can design semi-automatic, automatic and highly automated AAC production lines according to the required output and investment plan.

Actual output depends on product dimensions, density, raw material properties, working schedule, cutting cycle and autoclave configuration.

Key Quality Control Points

• Test the chemical composition and fineness of raw materials
• Maintain accurate automatic batching and formula control
• Control slurry density, temperature and mixing time
• Keep pre-curing temperature and cake strength stable
• Inspect cutting-wire tension and cutting accuracy
• Control the autoclave heating, pressure-holding and cooling cycle
• Test finished-product density, strength and dimensional accuracy

Why Choose HUAZHU?

• Complete AAC block and panel production line solutions
• Annual capacities from 50,000 to 500,000 m³/year
• Customized factory layout and equipment configuration
• Equipment manufacturing and quality inspection
• Installation guidance and commissioning support
• Operator and maintenance personnel training
• Long-term technical support and spare-parts service

HUAZHU provides AAC plant solutions for customers in Kazakhstan, Russia, Central Asia, Southeast Asia, Africa and other international markets.

Frequently Asked Questions

What are the main steps in the AAC production process?

The main steps are raw material preparation, automatic batching, mixing and pouring, pre-curing, demoulding and cutting, grouping, autoclave curing, separating and packaging.

What raw materials are required to produce AAC blocks?

Typical raw materials include sand or fly ash, cement, lime, gypsum, water and aluminum powder or paste. The final formula should be determined through raw material testing.

What production capacities can HUAZHU provide?

HUAZHU provides AAC block and panel production lines with annual capacities ranging from 50,000 to 500,000 m³/year.

Can the AAC production process be customized?

Yes. The process, equipment configuration and factory layout can be customized according to the customer’s raw materials, required capacity, product specifications, land conditions and automation level.

Does HUAZHU provide installation and commissioning?

Yes. HUAZHU provides installation guidance, commissioning support, operator training and long-term after-sales service.