Barium Complex Grease Manufacturing —
Heavy Water-Resistant NLGI 2 BOM

Barium complex grease uses barium 12-hydroxystearate plus complexing acid (azelaic, sebacic, or benzoic) and barium hydroxide as the thickener. Three key properties: (1) Exceptional water resistance — barium soap is highly hydrophobic, washout D1264 <1%. (2) Good high-temperature stability — drop >220 °C. (3) Heavy-load EP capability.

Used in: steel rolling mill bearings, paper machine wet end roll bearings, marine deck winch, dragline boom in monsoon, mine hoist with water seepage. Niche but irreplaceable in water-contaminated heavy-load applications. Largely replaced by CaSX in newer formulations due to barium handling concerns, much like the shift seen in lithium complex grease manufacturing for general high-temperature duty.

NLGI 2 barium complex grease BOM (%): Group I SN500 72%, 12-HSA 5%, azelaic acid 1.5%, Ba(OH)2·8H2O 6%, sulphurised olefin EP 4%, ZDDP 1.5%, aminic AO 0.7%, phenolic AO 0.5%, ASA + Ca sulfonate CI 1.5%, PIB tackifier 0.8%, Ca nitrite 0.5%, polyisoprene 0.5%, mineral spirits 5%, dye 100 ppm.

Process: saponify at 130-140 °C; complex with azelaic at 200-220 °C; dehydrate vacuum 180 °C; cool to 100 °C and add additives; mill to NLGI 2. Drop >220 °C, 4-ball weld 315 kgf, D1264 <1%.

Barium compounds have toxicity / handling concerns — barium hydroxide is highly alkaline and the soluble barium ion is acutely toxic. Workplace safety regulations (OSHA in US, MAK in EU) restrict barium exposure to low levels.

Grease manufacturers find handling Ba(OH)2 challenging — special dust-controlled facility, PPE, medical surveillance. Calcium sulfonate complex (CaSX) and lithium complex deliver similar water-resistance and high-temp performance without barium toxicity. Most new formulations now use CaSX. Legacy specifications still require barium complex, while plants seeking lower-toxicity routes often switch to aluminium complex grease manufacturing or a soap grade such as sodium soap grease manufacturing.

All three are valid heavy-duty water-resistant greases. Barium complex — best water resistance (D1264 <1%), historical Indian railway / steel mill standard. Toxicity concerns. CaSX — equivalent water resistance, inherent EP + CI, no toxicity. Higher cost ₹360-580 / kg vs barium ₹220-360 / kg.

Lithium complex — moderate water resistance (D1264 5-8%), lowest cost, standard wheel bearing / chassis grease; see our lithium grease manufacturing process and polyurea grease manufacturing guides for the non-barium routes. For new applications: CaSX is preferred. For replacement of legacy barium grease in matched specification: barium complex still in service.

Steel hot-strip mill and cold-strip mill roll bearings (Tata Steel Jamshedpur, JSW Vijayanagar, SAIL Bhilai, Bokaro) face exceptional duty — high radial load, water-cooled mill scale environment, high temperature near hot roll. Barium complex was the traditional grease.

Modern alternative: CaSX or polyurea. NLGI 2 standard, central lube system delivery. Indian mill consumption: large rolling mill uses 30-60 MT/year per stand. Brands: SKF LGEM 2, Shell Gadus S5 V100 2. ₹360-680 / kg. Producers tooling up for this volume should review the typical grease plant setup cost before committing to a barium line.

Paper machine wet end (forming section, press section) bearings face constant water spray and steam — extreme water-resistance requirement. Barium complex was traditional. Modern paper mills (ITC PSPD, JK Paper, BILT, Tamil Nadu Newsprint) use CaSX or polyurea more frequently now.

NLGI 2 for press section bearings, NLGI 1 for centralised lube systems with wet-end roll bearings. Indian paper-mill volume: 5-20 MT/year per mill depending on capacity.