A calcium silicate board fire rating covers two separate results. Euroclass A1 under EN 13501-1 says the board itself is non-combustible. Fire resistance in minutes, such as EI 60 or a 1-hour rating, belongs to a complete tested system under EN 1364 or ASTM E119, not the board alone. Thickness, framing, joints and fixings decide that number.
Gypsum plaster is made by grinding calcined gypsum to the required fineness, then batch-mixing it with retarder, water-retention agent, lime, perlite or limestone in measured doses. The blend goes through intermediate bins to a bag packer or bulk silo. Calcination makes the binder, but this dry-mix section decides how the plaster pumps, spreads, sets and stores.
A gypsum plaster retarder delays setting by interfering with the growth of gypsum crystals. Producers mostly use citric or tartaric acid, their salts, or protein hydrolysates. Published doses are small: about 0.04–0.06% in one machine-plaster formulation. Too much cuts strength, so the dose is set by trial on your own stucco, against a measured setting time.
Fly ash bricks are made by mixing fly ash with a lime or cement binder, sand and water, pressing the damp mix in a machine, then curing the bricks. One Indian state guideline uses 70% fly ash, 10% lime, 5% gypsum and 15% sand, with about two days on pallets followed by 10–14 days of water curing.
A clay suits a brick plant if it shapes without cracking, holds its form while drying, fires strong at a workable temperature and stays free of damaging impurities. To find out, test plasticity, grain size, shrinkage, carbonates, sulfur, carbon, soluble salts and fired properties on representative samples. Results decide the forming, drying and fuel route.
Brick kiln emissions are mainly particulate matter, sulfur dioxide, fluorides, nitrogen oxides, carbon monoxide and carbon dioxide. Much of the sulfur and fluorine comes from the clay, not only the fuel. Stack limits range from 250 mg/Nm³ of particulate in India to single-digit figures for US tunnel kilns, so the target market shapes the plant design.
An AAC block quality check runs through the whole plant, not only the finished block. The lab tests incoming lime, sand and cement, watches slurry temperature and rise, checks green cake strength before cutting, reviews autoclave logs, then tests density, strength, dimensions and shrinkage. Dubai’s factory rules, for example, require strength and size tests every production day.
AAC block production cost per m³ is the sum of a short list: lime, cement, silica source, gypsum, aluminum, steam, electricity, labor, wear parts and packing. On our reference mix, a B05 sand-based block uses roughly 55–110 kg of cement and 110–165 kg of lime per m³ (estimate). Multiply each quantity by your delivered local rate, then divide by saleable yield.
There is no fixed mini AAC plant cost, because “mini” covers very different scopes. For true autoclaved blocks, the smallest line we coordinate makes about 20,000 m³ a year. Below that, you still need a mill, boiler, cutter, autoclaves and laboratory, so cost per m³ rises steeply. Compare offers on scope and on autoclave arithmetic, not on the headline figure.
A gypsum board lamination machine bonds PVC film to the face of finished board and usually aluminum foil to the back. A saw line then cuts the sheet into tiles, commonly 595 × 595 or 600 × 600 mm, which are inspected and packed. It is a finishing line downstream of a board plant. It does not make board, so board supply decides the project.
