How to Set Up an AAC Block Plant: Planning Guide for Investors
This guide is for building-materials companies, investors and project developers evaluating a new plant for autoclaved aerated concrete (AAC) blocks. It is written by the YuxingCorp project team and covers plants from 20,000 to 300,000 m³ a year, built on sand or on fly ash.
It does not quote prices. An AAC plant is configured around its output, its raw materials, its steam supply and its site, and a figure given without those inputs would mislead more than it helps. Instead, this guide sets out the decisions to make first, the equipment a complete line needs, the process figures that decide plant size, the planning sequence we work through with buyers, the problems to avoid in a first plant, and a checklist you can send to any supplier so the proposals you receive can be compared line by line.
Last updated: October 2026
1. First, decide what you will make
Blocks first, panels later. AAC blocks and reinforced AAC (ALC) panels are made by the same process; panels add rebar mesh placed in the mould before pouring, plus mesh preparation and panel handling equipment. Most export plants start with blocks and add panels later as an upgrade, once the block line runs stably.
Block sizes. The standard block is 600 mm long, 100–300 mm wide and 200–300 mm high. Decide the widths your market builds with — they decide the cutting setup.
Density and strength. AAC is graded by dry density and compressive strength. Plants commonly produce density grades B03 to B07 (300–700 kg/m³) and strength classes A1.5 to A5.0. Lighter grades insulate better; denser grades carry more load.
The standard your customers specify. Production is designed to GB/T 11968 (China). If your customers buy to European or US rules, product testing can be aligned to EN 771-4 or ASTM C1691 — settle this before the line is configured, not after the first batch.
2. What determines the size and cost of an AAC plant
- Annual output. Output, in m³ per year, sets the size of the ball mill, the number of moulds and autoclaves, the boiler and the building. Plants range from 20,000 to 300,000 m³ a year; most export plants are 50,000, 100,000 or 200,000 m³. As a reference, a 100,000 m³ line runs six φ2 × 21 m autoclaves.
- Raw material route: sand or fly ash. Both work. Fly ash suits plants near coal-fired power stations; silica sand is used everywhere else.
- Sand-based mix — cement 10–20%, lime 20–30%, sand 55–65%, gypsum up to 3%
- Fly ash-based mix — cement 6–15%, lime 18–25%, fly ash 65–70%, gypsum 3–5%
- Aluminium paste, the gas-forming agent, is dosed at about 0.45 kg per m³ of finished product.
- Steam. The autoclaves run on steam from a boiler — about 4 t/h for a 20,000 m³ line and 8 t/h (1.6 MPa) for a 100,000 m³ line. The boiler can be specified for coal, biomass, oil or gas, depending on what is available at your site and your emission rules.
- Site and buildings. As a reference, a 200,000 m³ a year plant needs about 2.2–3.7 ha of land (33–55 mu) and 6,000–21,000 m² of buildings, depending on layout and on how much finished-block storage you plan.
- Civil works. Foundations for the ball mill, the cutting line and the autoclaves, plus rails and the boiler house, are a large part of the project. They are carried out locally to our drawings, or by a construction contractor we coordinate if you prefer.
- Utilities. Power capacity, water consumption and compressed air are listed for each capacity in the technical proposal. Check them against your site supply early.
3. The equipment in a complete line
- A. Raw material preparation — wet ball mill for sand or fly ash (φ900 × 2100 mm on a small line, φ1200 × 4500 mm on a 100,000 m³ line), slurry tanks and pumps, silos for lime, cement and gypsum, and dosing and weighing.
- B. Mixing and pouring — a 4.2 m³ mixer and a pouring car on a 100,000 m³ line. The mix is poured into the moulds at 45–48 °C.
- C. Moulds and pre-curing — 4.2 × 1.2 × 0.6 m steel moulds. The aluminium paste releases hydrogen and the mix rises into a cellular cake, which pre-cures for typically 2–4 hours at 40–50 °C until it reaches 0.15–0.18 MPa and can be cut.
- D. Cutting — a tilting six-side wire cutting machine: the cake is turned 90° in the air, demoulded, then cut lengthwise and crosswise, in about 6 minutes per mould, with a cutting tolerance of ±3 mm in length and ±1 mm in width and height — the GB/T 11968 tolerance for thin-joint blocks.
- E. Autoclave curing — autoclaves of φ2 × 21 m as standard, six on a 100,000 m³ line, and φ2.5 or φ2.85 × 26 or 31 m on larger lines, with autoclave cars, rails and transfer equipment. Blocks cure at 1.3–1.4 MPa (190–200 °C) with 7 hours at full pressure; a full cycle — loading and unloading, vacuum, pressure rise, holding and pressure release — takes about 11 hours.
- F. Steam — boiler, steam distribution and condensate handling, sized to the autoclaves.
- G. Separating and packing — the cured cakes are separated into blocks and packed for the yard.
- H. Waste and dust — 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.
4. Timeline: seven stages from brief to stable production
Stage 1: Define the requirement. Block sizes, density and strength grades, the standard your customers specify, annual output, raw materials, fuel for the boiler, site, and target timeline.
Stage 2: Raw material testing and supplier comparison. Your raw materials are tested and trial batches confirm the formula. Configurations from different manufacturers are compared against the same brief, so differences in scope and inspection terms are visible before price is discussed. Our commitment: “A written sourcing report within 48 hours of a complete requirement brief.” “Custom or multi-line projects may take longer — we tell you upfront.”
Stage 3: Contract and payment. Standard terms: T/T 30% deposit, 70% balance before shipment. “We confirm which certificates are available before contract.”
Stage 4: Manufacturing and pre-shipment inspection. Ball mills and autoclaves are heavy equipment with long manufacturing times: the first equipment ships about 4–5 months after the deposit, and the complete line in 5–6 months. Autoclaves are pressure vessels and are delivered with Chinese GB/TSG pressure vessel certification. “Every shipment comes with a full pre-shipment inspection report — test-run records, functional and dimensional checks, photos and video — before the equipment leaves the factory.” Third-party inspection (e.g. SGS, BV, TÜV) or ASME documentation for the autoclaves can be arranged on request; the fee is paid by the buyer and is not included in the equipment price.
Stage 5: Export documents and shipment. “Complete export document pack — commercial invoice, packing list, certificate of origin, bill of lading, and manufacturer certificates such as CE or EAC where applicable.” We coordinate shipping and freight logistics. “Import customs clearance, duties, taxes and local registration are the buyer’s responsibility.”
Stage 6: Installation and commissioning. We send 3–4 engineers — process, mechanical, electrical and thermal — to supervise installation, autoclave commissioning and trial production, typically on site for 2–3 months, depending on the progress of civil works. Travel and accommodation are at the buyer’s cost.
Stage 7: Training, running-in and warranty. Your operators and maintenance staff are trained during installation and trial production, with remote technical support afterwards. A recommended two-year spare parts list is quoted with the line. “12-month equipment warranty from the date of commissioning, with a named responsible contact.”
5. Checklist: what to prepare before you request quotes
Send the same list to every supplier you are talking to. Proposals built on the same inputs are the only ones you can compare.
- Products: blocks only, or blocks now and ALC panels later
- Block sizes: lengths, widths and heights your market uses
- Density grades and strength classes
- The product standard your customers specify (GB/T 11968, EN 771-4, ASTM C1691 or local)
- Annual output target (m³ per year)
- Raw materials available locally — sand or fly ash, lime, cement, gypsum — with analysis reports, and whether you can send 30–50 kg samples for testing
- Fuel available for the boiler, and local emission rules
- Power supply: voltage, frequency, available capacity; water supply
- Site: land and building dimensions; new building or existing
- Who will carry out the civil works
- Pressure vessel rules in your country, and any third-party inspection you need
- Destination country and target timeline
6. Eight problems to avoid in a first AAC plant
- Fixing the line before testing your raw materials. Sand, fly ash and lime vary from source to source, and the mix decides how the cake rises, cuts and cures. Send 30–50 kg of your materials for laboratory tests and trial batches before the configuration is final.
- Choosing the standard after the first batch. If your customers buy to EN 771-4 or ASTM C1691, say so at the start; density grades, strength classes and testing are planned around it.
- Leaving autoclave certification to the end. Autoclaves are pressure vessels. Check your country’s registration rules early, and decide before shipment whether you need third-party inspection or ASME documentation.
- Planning the boiler around a fuel you cannot get. If natural gas is not available at your site, specify the boiler for coal, biomass or oil from the start, and check the emission rules for that fuel.
- Undersizing steam. The boiler has to serve autoclaves cycling one after another. Size it for the full line, not for one autoclave.
- Starting with panels. Reinforced ALC panels add mesh preparation and panel handling. Get the block line running stably first; panels can be added as an upgrade.
- Underestimating civil works. Ball mill and autoclave foundations, rails and the boiler house often set the pace of the whole project. Start them as soon as the layout drawings are fixed.
- No plan for waste and dust. Return cutting waste and waste slurry to batching, recycle process water and fit dust collectors at powder handling points from day one — it saves raw material and keeps the plant within environmental rules.
7. AAC plant FAQs
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?
Plants range from 20,000 to 300,000 m³ a year; the most common export sizes are 50,000, 100,000 and 200,000 m³. We help you size the plant against your local market demand.
How long does a project take?
The first equipment ships about 4–5 months after the deposit and the complete line in 5–6 months. Installation, autoclave commissioning and trial production then take typically 2–3 months on site, depending on civil works.
Which standards can the blocks meet?
Production is designed to GB/T 11968, with density grades B03–B07 and strength classes A1.5–A5.0. Product testing can be aligned to EN 771-4 or ASTM C1691 on request.
What fuel does the boiler need?
Coal, biomass, oil or gas, depending on local availability and emission rules.
Who does the civil works?
Local contractors, to our drawings — or a construction contractor we coordinate if you prefer.
What do you need to prepare a proposal?
Your target output, block sizes and density grades, raw materials available, fuel for the boiler, project location and planned timeline.
8. What we handle
- Equipment sourcing & supplier coordination
- Pre-shipment quality inspection report; third-party inspection on request (buyer’s cost)
- Export documentation — invoice, packing list, certificate of origin, bill of lading
- Manufacturer certificates (e.g. CE, EAC) where available
- Shipping & freight logistics coordination
- Installation guidance & commissioning support
9. Related
Autoclaved fly ash and sand-lime brick line
Planning a gypsum board plant instead?
Planning an AAC block plant?
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