| Single-roll crusher | Often used for primary reduction of friable to moderately hard materials, including coal, shale, and some limestone. | A rotating roll works against a breaker plate, crushing material mainly by compression and, depending on the design, impact. | Suitable where a relatively simple primary crusher is needed and the feed can be broken against a fixed plate. | Can accept relatively large feed; comparatively straightforward layout; tooth or pick designs can help engage lumpy feed. | Very hard, highly abrasive feed can accelerate wear. Check feed size, breaker-plate arrangement, and the required product size before selection. |
| Smooth double-roll crusher | Commonly used for brittle, relatively uniform feed such as coal, coke, and some minerals or laboratory samples. | Two counter-rotating smooth rolls draw material into the gap and reduce it primarily by compression. | Best when feed is dry or only slightly damp, reasonably free-flowing, and a controlled product size is important. | Adjustable roll gap provides a practical way to control product top size; compression crushing can limit excess fines for suitable feed. | Sticky or fibrous material may pack or bridge. Hard, abrasive particles can cause substantial roll wear; a narrow gap does not guarantee a precise size distribution. |
| Toothed double-roll crusher | Often selected for coal, lignite, shale, and other relatively soft or friable materials; tooth design must match the feed. | Teeth bite, shear, and pull material through the rolls rather than relying solely on smooth-roll compression. | Useful for coarse reduction of lumpy feed, particularly when bite and draw-in are more important than a tightly graded product. | Can handle larger lumps than a comparable smooth-roll arrangement; tooth engagement can improve draw-in and reduce the need for extensive pre-sizing. | Product may be less uniform than from smooth rolls. Tooth profile, spacing, and wear condition affect performance; highly abrasive feed can wear teeth quickly. |
| Low-speed mineral sizer | Commonly applied to friable materials such as coal and some soft to medium-strength ores, including feed that may be wet or clay-bearing. | Two slow-turning toothed shafts use sizing, shearing, and compression actions to break material between the shafts and comb structures. | A candidate for primary sizing of variable, lumpy, or damp feed when a low-speed crushing action is preferred. | Low shaft speed and open tooth arrangements can help with difficult, irregular feed; modular tooth designs can be selected for different applications. | Not a universal solution for hard, highly abrasive rock. Check the material’s abrasiveness, clay behavior, tramp-metal risk, and the required reduction before choosing a sizer. |
| Four-roll crusher | Used for staged reduction of suitable brittle or friable materials, including some coal and mineral applications. | Two pairs of rolls reduce material in successive stages within one machine. | Consider where two-step reduction and a more compact arrangement are useful and the feed is appropriate for roll crushing. | Combines primary and secondary roll-crushing stages in a single assembly; stage gaps can be configured for the process target. | More rolls and adjustments add maintenance and setup considerations. Confirm that feed distribution, wear management, and required product sizing suit the arrangement. |
| Selection guide | Choose by testing the actual material and operating conditions—not by crusher type alone. Compare feed size and shape, compressive strength, abrasiveness, moisture and clay content, required product size, throughput, and tolerance for fines. Confirm the proposed roll gap or tooth configuration with application data, and account for wear parts, tramp-material protection, and downstream screening. |