High-temperature resistant cement production solutions — calcium aluminate cement with 40-80% alumina content for kiln linings, furnaces, incinerators, and foundry applications. Capable of withstanding sustained temperatures from 1300°C to over 1800°C.
Overview
Refractory cement — also known as calcium aluminate cement (CAC) or high-alumina cement — is a specialized hydraulic binder designed to withstand extreme temperatures that would destroy conventional Portland cement.
Refractory cement is fundamentally different from Portland cement in both chemistry and function. While OPC is based on calcium silicates (C3S, C2S), refractory cement is based on calcium aluminates — principally monocalcium aluminate (CaO·Al2O3, or CA) and dicalcium aluminate (CaO·2Al2O3, or CA2) — which form a ceramic bond at high temperatures rather than decomposing.
The alumina (Al2O3) content of refractory cement ranges from 40% to 80%, depending on the grade. Higher alumina content translates to higher maximum service temperature. Standard Portland cement, in contrast, contains only 5-6% Al2O3 and begins to lose strength above ~300°C as the hydrated calcium silicate phases decompose.
Refractory cement serves as the bonding agent in refractory castables — premixed blends of refractory aggregates and the cement binder that are mixed with water and cast into monolithic linings for high-temperature industrial equipment. The cement hydrates like OPC at room temperature, then transitions to a ceramic bond as the lining heats up during service. LIMING provides complete production solutions for all grades of refractory cement.
Raw Materials
The quality of refractory cement begins with the quality and purity of its raw materials — primarily bauxite and limestone.
Bauxite is the primary source of alumina (Al2O3) for refractory cement. High-grade bauxite with 50-85% Al2O3 and low iron oxide (Fe2O3 <2%) is required. The silica (SiO2) content must also be controlled, as excessive silica dilutes the alumina content and reduces refractory performance. Major bauxite sources include China (Shanxi, Guizhou), Guyana, Brazil, and India.
High-purity limestone (CaCO3 >95%) supplies the calcium oxide (CaO) component. The ratio of bauxite to limestone is precisely controlled to achieve the target Al2O3/CaO ratio and the desired mineral phases in the finished cement. Typical mixes range from equal parts bauxite and limestone for low-alumina grades to much higher bauxite proportions for high-alumina grades.
The two materials are proportioned to achieve a target Al2O3/CaO ratio in the raw meal. For standard-grade refractory cement (40-50% Al2O3), roughly equal weights of bauxite and limestone are used. For high-alumina grades (70-80% Al2O3), the proportion shifts to approximately 70% bauxite / 30% limestone.
Production Process
The manufacturing process follows a high-temperature route — either sintering in a rotary kiln or fusion in an electric arc furnace.
Product Properties
Refractory cement's unique combination of rapid setting, high alumina content, and thermal stability distinguishes it from all other cement types.
Core Equipment
Refractory cement manufacture requires robust equipment capable of handling hard, abrasive materials and high process temperatures.
Heavy-duty jaw crusher and cone crusher for reducing high-hardness bauxite ore from mine-run size to <30mm feed for the raw mill.
Two-chamber ball mill with wear-resistant liners for grinding bauxite and limestone together or separately to the required raw meal fineness.
Kiln designed for sintering calcium aluminate clinker at ~1450°C, with enhanced refractory lining in the burning zone to handle the elevated temperature.
For producing fused calcium aluminate cement, the raw mix is melted at 1700-1800°C in an EAF, then cast into ingots and crushed — yielding a denser, higher-purity product.
High-wear-resistance ball mill with hard alloy liners and grinding media, sized for the harder-than-OPC refractory clinker.
Sealed packing machine with desiccant dosing and multi-layer moisture-barrier bags to protect the hygroscopic cement during storage and transport.
Applications
Refractory cement is the essential bonding agent wherever high-temperature industrial processing demands durable, heat-resistant linings.
Why LIMING
We bring specialized know-how in high-temperature processing and hard material grinding to every refractory cement project.
Rotary kilns engineered for sustained operation at 1450-1600°C with optimized refractory lining design for long campaigns.
Crushers, mills, and conveyors specified for bauxite and refractory clinker with wear-resistant designs throughout.
One plant can produce multiple Al&sub2;O&sub3; grades (low, medium, high) through raw mix adjustment — maximizing market reach.
We configure either the sintering route (rotary kiln) or fusion route (electric arc furnace) based on your product grade targets.