Performance and material selection in industrial filtration
Filtration plays a critical role in improving air quality, particularly in industries such as steel, cement and mining. In these sectors, filter cost and service life are key performance indicators. Premature failure of filter bags leads to increased costs, production losses, and environmental concerns, while frequent replacement also raises labour and operational expenses. Therefore, durability and extended service life are central to the evaluation of filtration systems. Baghouse filtration systems are among the most effective industrial separation technologies for capturing fine particulates. However, evaluating performance solely based on initial filtration efficiency is insufficient. Parameters such as pressure drop, cleanability, dimensional stability, and bag lifetime must be considered together to ensure long-term efficiency and reliability. Polyacrylonitrile (PAN) fibres are widely used in industrial filtration due to their high thermal stability, low shrinkage, resistance to many organic solvents, and strong hydrolysis resistance. These properties make PAN-based materials particularly suitable for demanding process environments such as cement plants, where acidic conditions are prevalent.
Operating conditions and material performance in cement plants In the cement industry, hot gas filtration is characterised not only by high temperatures but also by dynamic conditions involving fluctuating humidity and chemical loading. These factors directly affect both filtration performance and material durability. For this reason, homopolymer acrylic fibres have been developed to provide long-term mechanical and chemical stability under elevated temperatures and harsh operating environments. The preference for homopolymer fibre-based filter bags in cement plants is driven by several factors, including stable performance within the medium temperature range of 120–140 °C, strong chemical resistance in acidic environments, and cost-effectiveness achieved through extended service life. These characteristics help reduce maintenance frequency while supporting operational continuity. While homopolymer fibres are recognised in the literature for their chemical and thermal stability, the performance of filter media in cement applications extends beyond particulate capture. Materials must also withstand aggressive process gases, humidity fluctuations, and continuous mechanical stress. Therefore, material selection should not be limited to temperature resistance alone, but should also consider the ability to maintain mechanical, chemical, and dimensional integrity under real operating conditions.
Impact of dimensional stability on filtration performance Dimensional stability is a critical performance parameter in practical applications. Changes such as shrinkage, elongation, or deformation during service can negatively impact filtration efficiency. These changes may increase friction between the bag and cage, cause stress concentration at seams, and lead to sealing issues at the bag opening. Acryterna homopolymer fibre has been specifically engineered to minimise these risks through its ‘no dimensional change’ characteristic. This stability ensures predictable bag behaviour, balanced load distribution, and more efficient maintenance planning.
Conclusion The performance of materials used in hot gas filtration in the cement industry should be evaluated from both polymer chemistry and field performance perspectives. PAN-based structures offer a balanced combination of mechanical strength, thermal stability and chemical resistance, while known degradation mechanisms under hydrolysis highlight the importance of proper material selection. In this context, homopolymer acrylic fibres stand out as a reliable and sustainable solution for demanding filtration conditions.
The Centre has deferred environmental clearance for a proposed limestone mine near a Great Indian Bustard habitat in Ramgarh, Rajasthan’s Jaisalmer district. The critically endangered species has an estimated wild population of about 130 in India.
The Telangana government will supply cement at a subsidised price of Rs. 230 per 50-kg bag to poor and low-income families allotted Indiramma houses. The prevailing market price is between Rs. 310 and Rs. 320 per bag, the Assembly was informed on Thursday.
Channel checks show cement demand remained healthy with volume growth estimated at six to seven per cent in July and August 2026. Trade prices were broadly stable while non-trade prices were volatile in the East, and attempted hikes were rolled back amid higher competition. Average fuel costs rose in August by five to nine per cent, lifting spot petcoke and coal prices.
All-India trade price remained flat month on month in August as increased rake supplies and competition offset early increases. Monsoon related demand softness limited sustained hikes and dealers indicated further attempts would depend on demand trends. Combined July and August volumes were estimated at six to seven per cent, supported by infrastructure spending while retail housing remained weather sensitive.
In the South, a Rs20 a bag hike in August did not hold and prices stayed flat month on month, while dealers planned Rs25 to Rs30 a bag from fifth September 2026 but with uncertain sustainability. In the East, trade prices were unchanged and non-trade prices corrected by Rs15 to Rs20 a bag amid weak construction in West Bengal, Jharkhand and Odisha.
The West remained most resilient on pricing and demand despite attempted hikes of Rs10 to Rs15 a bag, and Gujarat saw relatively better volumes in August. North and Central markets kept prices range bound as players focused on ramping up utilisation of new capacity, with schemes of up to Rs2 to Rs3 a bag used to meet month-end targets. Overall construction activity improved as the monsoon eased, aiding a pickup in several states.
Fuel cost pressures persisted, with South African coal at USD114 a t and petcoke around USD146 to USD147 a t in August, while spot imported petcoke and coal were higher. Imported coal consumption cost stood at Rs2.07 per Kcal and petcoke at USD2.11 per Kcal. Analysts estimate the all-India trade spread to decline by Rs90 to Rs100 a t quarter on quarter, weighing on near-term profitability and they prefer UltraTech Cement (UTCEM), JK Cement (JKCE) and Grasim Industries (GRASIM).