Heavy duty, continuous type ball mill is with three compartment with screen. Replaceable Liners are fixed entire mill (inside). Liner material and shape is selected based on material to be grind. Material is fed in two primary grinding compartments, which carries large diameter balls for reduce particle size. Material comes into second compartment. Second compartment is carry smaller size media for grinding. Material comes into third compartment for fine grinding, which carry small size media. Diaphragms may place to regulate material level and control retention time. Material is feed and discharged through hollow trunnion at opposite end. Accessories like air classifier, cyclone, blower, return air circuit or dust collector can also be placed for close loop system. Two tiers fixed on both end of mill, which are rotate on four rollers. Rollers are fixed on support and oil immersed. Mill rotates on four roller and two tiers. Girth gear is fixed on shell, which driven mating gear, gearbox and motor, which are fixed on heavy drive base.