AAC Block Production Line
AAC block production lines for sand or fly ash — ball milling, pouring, tilting wire cutting and autoclave curing for lightweight, insulating autoclaved aerated concrete blocks.
AAC Block Production Lines We Supply
AAC Block Production Process
Raw material milling → dosing and mixing → pouring into moulds → pre-curing → tilting and wire cutting → autoclave curing → separating and packing.
Sand or fly ash is wet-milled in a ball mill into a slurry, then dosed and mixed with lime, cement, gypsum and aluminium paste and poured into steel moulds at 45–48 °C. The aluminium reacts in the mix and releases hydrogen, which aerates it into a light, cellular cake. The cake pre-cures — typically 2–4 hours at 40–50 °C — until it reaches 0.15–0.18 MPa and can be cut cleanly. It is then tilted, demoulded and wire-cut on six sides into blocks, and cured in autoclaves under high-pressure saturated steam, which gives AAC its strength and dimensional stability.
Raw Materials: Sand-Based or Fly Ash-Based AAC
We build both. Fly ash suits plants near coal-fired power stations and puts power-plant waste to use; silica sand is used everywhere else.
| Mix | Cement | Lime | Silica source | Gypsum |
|---|---|---|---|---|
| Sand-based | 10–20% | 20–30% | Sand 55–65% | Up to 3% |
| Fly ash-based | 6–15% | 18–25% | Fly ash 65–70% | 3–5% |
Aluminium paste is dosed at about 0.45 kg per m³ of finished product. Local raw materials always differ, so send us 30–50 kg of yours: we run laboratory tests and trial batches before the formula and the line configuration are fixed.
AAC Production Line Equipment
| Equipment | Typical configuration |
|---|---|
| Ball mill | φ900 × 2100 mm for a small line; φ1200 × 4500 mm for a 100,000 m³ a year line |
| Mixing and pouring | A 4.2 m³ mixer and a pouring car on a 100,000 m³ line |
| Moulds | 4.2 × 1.2 × 0.6 m steel moulds |
| Cutting machine | Tilting six-side wire cutting: the cake is turned 90° in the air, demoulded, then cut lengthwise and crosswise — about 6 minutes per mould, with a cutting tolerance of ±3 mm in length and ±1 mm in width and height |
| Autoclaves | φ2 × 21 m as standard, six on a 100,000 m³ line; φ2.5 or φ2.85 × 26 or 31 m on larger lines |
| Steam boiler | 4 t/h for a 20,000 m³ line; 8 t/h (1.6 MPa) for a 100,000 m³ line; coal, biomass, oil or gas fired |
Cutting waste and waste slurry are returned to batching, process water is recycled, and pulse-jet dust collectors are fitted at every powder handling point.
Autoclave Curing Cycle
Blocks are cured at 1.3–1.4 MPa (190–200 °C) with 7 hours at full pressure. A full cycle takes about 11 hours:
| Stage | Duration |
|---|---|
| Loading and unloading | 0.5 h |
| Vacuum | 0.5 h |
| Pressure rise | 1.5 h |
| Holding at 1.3–1.4 MPa | 7 h |
| Pressure release | 1.5 h |
Autoclave capacity and cycle time, together with the number of moulds in circulation, set the real output of the plant. Autoclaves are pressure vessels: they are delivered with Chinese GB/TSG pressure vessel certification, and third-party inspection (for example SGS, BV or TÜV) or ASME U-stamp documentation can be arranged before shipment on request, at the buyer’s cost.
AAC Block Sizes, Grades and Standards
| Block size | Length 600 mm; width 100–300 mm; height 200–300 mm |
| Density grades | B03–B07 (300–700 kg/m³) |
| Strength classes | A1.5–A5.0 to GB/T 11968-2020 |
| Dimensional tolerance | ±3 mm length, ±1 mm width and height — the GB/T 11968 tolerance for thin-joint blocks |
- GB/T 11968-2020 (China) is the design basis for density grades and strength classes.
- EN 771-4 (Europe) and ASTM C1691 (unreinforced AAC masonry units, US) — product testing can be aligned to either on request. ASTM C1693 covers autoclaved aerated concrete itself: a cementitious product based on calcium silicate hydrates, cured under high-pressure steam.
- For reference, the European AAC association gives AAC densities of 300–800 kg/m³, compressive strengths of 2.5–6 N/mm² and thermal conductivity of 0.08–0.16 W/(m·K), depending on density (Aircrete Europe).
Reinforced AAC (ALC) panels use the same process with rebar mesh placed in the mould before pouring. Most export plants start with blocks and add panels later.
Capacity, Site and Project Timeline
| Capacity range | 20,000–300,000 m³ a year; a small AAC production line starts at about 20,000 m³, and most export lines are 50,000, 100,000 or 200,000 m³ |
| Site for a 200,000 m³ plant | About 2.2–3.7 ha of land and 6,000–21,000 m² of buildings |
| Delivery | First shipment about 4–5 months after down payment — ball mills and autoclaves are heavy equipment — and the complete line in 5–6 months |
| Installation and commissioning | 3–4 engineers (process, mechanical, electrical, thermal) on site for 2–3 months, depending on civil works |
| Civil works | Carried out locally to our drawings, or by a construction contractor we coordinate |
These are typical figures; your output, raw materials and site decide the final configuration and schedule. For the full planning sequence, read our AAC block plant setup guide. For other autoclaved products, see our autoclaved brick production line.
What to Send for a Quotation
- Target output (m³ a year)
- Block sizes, density grades and the standard your market uses
- Raw materials available: sand or fly ash, lime, cement — with analyses, and whether you can send 30–50 kg samples
- Fuel available for the steam boiler
- Power supply (voltage, frequency, available capacity)
- Land or building dimensions
- Destination country and target timeline
With your output target, destination country and timeline we can start, and you receive a written sourcing report within 48 hours of a complete requirement brief.
Comparing block and brick technologies? See the autoclaved fly ash and sand-lime brick line (same autoclave and steam system), the concrete block and brick making machine line (no autoclave), the hollow core cement wall panel line for precast wall panels, and all our building materials production lines. For planning steps, read the AAC block plant setup guide.
One Partner from Requirement to Running Line
- Requirement review — capacity targets, site conditions and budget
- Equipment selection and supplier matching — vetted Chinese manufacturers
- Plant layout planning — civil works drawings issued early
- Quality inspection and factory acceptance testing before shipment
- Export documentation and freight coordination
- Installation, commissioning and operator training
Frequently Asked Questions
Can you work with our local raw materials?
Yes — we build both sand-based and fly ash-based lines. Send us 30–50 kg of your raw materials: we run laboratory tests and trial batches to confirm the formula before the line configuration is finalised.
Which capacity should I start with?
Lines range from 20,000 to 300,000 m³ a year; the most common export sizes are 50,000, 100,000 and 200,000 m³. A 200,000 m³ plant typically needs 2.2–3.7 ha (33–55 mu) of land and 6,000–21,000 m² of buildings. We help you size the plant against your local market demand.
Should I produce blocks or reinforced ALC panels first?
Blocks first is the common route. Panels add rebar mesh preparation and panel handling equipment, and can be added later as an upgrade.
Which product standards do you follow?
Production is designed to GB/T 11968 (China), with density grades B03–B07 and strength classes A1.5–A5.0. Product testing can be aligned to EN 771-4 (Europe) or ASTM C1691 (US) on request.
The autoclave is a pressure vessel — how does certification work?
Autoclaves are delivered with Chinese GB/TSG pressure vessel certification. Third-party inspection (for example SGS, BV or TÜV) or ASME U-stamp documentation can be arranged before shipment on request, at the buyer’s cost.
Natural gas is not available at our site. What are the boiler options?
The steam boiler can be specified for coal, biomass, oil or gas, depending on local fuel availability and emission rules. Fuel selection is part of the project definition stage.
What are the power and water requirements?
A complete utility list — power capacity, water consumption and compressed air — comes with the technical proposal for each capacity.
How long does a project take, and who does the civil works?
The first equipment ships about 4–5 months after down payment and the complete line in 5–6 months. Our 3–4 engineers supervise installation, autoclave commissioning and trial production, typically on site for 2–3 months. Civil works are carried out locally to our drawings, or by a construction contractor we coordinate if you prefer.
Is AAC production environmentally friendly?
Cutting waste and waste slurry are returned to batching, process water is recycled, and pulse-jet dust collectors are fitted at every powder handling point. Fly ash-based lines also put power-plant waste to use.
What about spare parts and training?
A recommended two-year spare parts list is quoted with the line. Your operators and maintenance staff are trained during installation and trial production, with remote technical support afterwards.
What do you need to prepare a quotation?
Your target output, block sizes and density grades, raw materials available (sand or fly ash, lime, cement), fuel for the boiler, project location and planned timeline.
Request an AAC Block Line Proposal
Tell us your target output, block sizes and raw materials. We respond within one business day.
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