India’s cement sector is in the midst of a structural growth phase. Performance of every production asset carries greater commercial consequence than before.

Total installed capacity of cement reached approximately 690 million tonnes per year by early 2026, with production touching 453 million tonnes in 2025 — a 6.3% year-on-year increase. According to CRISIL Ratings, Indian cement producers are expected to invest nearly ?1.2 lakh crore in capacity expansion between 2026 and 2028, with 160–170 million tonnes of new grinding capacity forecast to come online. Demand is projected to rise from 445 MMT in 2024 to 670 MMT by 2030, underpinned by government infrastructure programmes, affordable housing schemes and rapid urbanisation.
Among the most critical assets of a cement plant is the refractory lining of the rotary kiln. In the burning zone, where temperatures regularly exceed 1,450°C, the right choice of brick can mean longer campaigns, reduced maintenance cycles, and more consistent output.

Rotary kiln: A demanding environment
The rotary kiln is the core thermal unit in cement clinker production. Raw meal enters at one end at a few hundred degrees Celsius and is progressively heated to around 1,450°C at the burning zone, where clinker nodules form. The steel kiln shell must be continuously protected from this extreme environment, which is the job of the refractory lining.
Refractory bricks serve multiple simultaneous functions: insulating the shell from heat, resisting chemical erosion from clinker melt, alkali vapours, sulphur compounds and chlorine, and withstanding the mechanical stresses of a continuously
rotating system.

CALDE® MAG bricks: Engineered for critical zones
Calderys’ CALDE® MAG bricks range comprises a family of magnesia-spinel bricks engineered specifically for the transition and burning zones of cement and lime rotary kilns.
The bricks are made from a blend of high-purity magnesia (MgO) and active spinel, a crystalline compound formed from magnesia and alumina, which offers thermochemical stability, mechanical toughness, and controlled coating behaviour. The range features low thermal conductivity and controlled expansion.

Why brick quality matters commercially
The economic argument for high-quality refractory bricks is often underweighted when procurement decisions are driven by initial unit cost. For a cement plant operating at the scale typical of India’s major producers, an unplanned kiln outage carries significant costs: lost production, fuel to bring the kiln back to temperature, relining labour, and potential mechanical damage to the shell.
Many plants increasingly use alternative fuels and locally sourced raw materials, which can alter the alkali-sulphur balance within the kiln atmosphere and accelerate lining corrosion. Magnesia-spinel bricks of the hercynite type address this directly, with reduced alumina content limiting the formation of low-melting calcium aluminates that would otherwise compromise brick integrity.

Local manufacturing as a strategic advantage
A brick ordered from an overseas supplier may meet technical specifications on paper, but a six-to-eight-week lead time following an unplanned outage becomes part of the total cost of failure. Local manufacture provides shorter lead times, ready inventory of fast-moving grades, and faster emergency response.
Bricks manufactured and tested in India, against data from Indian kiln operations, can be more precisely calibrated to local raw material chemistry, fuel types, and operating practices. Looking ahead, Calderys is expanding its Indian footprint through the CAPES facility in Odisha — a new plant housing multiple production lines for both monolithic refractories and shaped bricks, strategically located within one of India’s most active industrial belts.

Sources: IBEF Cement Industry Report; Mordor Intelligence India Cement Market; CRISIL/S&P Global, November 2025; CemNet, November 2025; calderys.com

(Communication by the management of the company)