What is the difference between a rod mill and a ball mill, and when should each be used?

A rod mill uses long steel rods that contact material along line contacts, producing a selective grinding action that preferentially breaks larger particles while passing already-fine material with minimal further reduction – resulting in a narrower particle-size distribution and less overgrinding. A ball mill uses spherical media with point contacts, producing a more random grinding action […]

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What is the difference between open-circuit and closed-circuit operation?

In open-circuit operation, material passes through the mill once and the discharge is the final product – simple to operate but typically produces a wider particle-size distribution with some over-ground and under-ground material. In closed-circuit operation, mill discharge is fed to a classifier (hydrocyclone or spiral classifier); correctly-sized material proceeds to the next process step while […]

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What determines the ball charge size and how often does it need topping up?

Ball load (shown in the specification table) is the total mass of steel grinding balls in the mill at normal operating fill level – typically 30–35% of internal mill volume. Balls wear at a rate dependent on feed abrasiveness, ball hardness, and mill operating parameters; typical wear rates range from 0.5–1.5 kg of steel consumed per […]

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How is the correct ball mill model selected for a given application?

Model selection depends on required throughput (t/h), target output particle size, feed hardness (work index), and feed top size after primary crushing (typically ≤25 mm for this series). As a starting point, match required throughput to the capacity range in the specification table at the target output size band (0.074–0.4 mm for most models, 0.075–0.89 […]

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How is the correct frame size selected for a given application?

Frame selection depends on three factors: required daily capacity (t/d), maximum feed lump size, and material hardness/abrasiveness. As a starting point, match your required capacity to the t/d range in the specification table – but note that capacity is also affected by material hardness (the t/d figures are typically based on materials with a Mohs hardness […]

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Can the finished particle size be adjusted without changing the rollers?

Yes, within the 0.044–0.125 mm (125–325 mesh) range, finished particle size is primarily controlled by the analyzer (classifier) motor speed. Increasing classifier speed returns more material to the grinding zone for further reduction, producing a finer finished product; decreasing classifier speed allows coarser material to pass, increasing throughput at a coarser particle size. For target […]

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What is the difference between the 3-roller and 4-roller configurations on the 9716 and 9918 frames?

Both configurations share the same mill housing, main shaft, and classifier. A 4-roller configuration adds one additional grinding roller and ring set around the main shaft, increasing the grinding surface area in contact with the material at any instant. This raises throughput by approximately 25–30% within the same frame footprint at a modest increase in […]

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How is the screen mesh selected for a specific application?

Mesh aperture is selected based on the smallest particle size that must be retained on the deck for dewatering – particles smaller than the aperture pass through with the drainage water and are not dewatered by that deck. For washed coarse sand and aggregate (typically retaining everything above 0.15–0.3 mm), apertures of 0.5–1 mm are common. […]

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Why does the TS screen use a steep operating angle compared to a standard horizontal screen?

A steep angle (25–30°) maximises the gravity component acting to drain free water from the slurry layer as soon as it lands on the deck. This rapid initial drainage is the single largest contributor to overall dewatering performance – most free water separates within the first portion of the deck length. The remaining deck length, combined […]

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