Differences: roller crusher vs. jaw crusher
Published: October 26, 2023
When selecting primary crushing equipment, mining and aggregate professionals often face the critical decision between roller crushers and jaw crushers. While both serve as essential size reduction machines, they operate on fundamentally different principles and excel in distinct applications. Roller crushers utilize compression between two rotating cylinders to fracture materials, making them ideal for secondary crushing and handling softer, friable materials with minimal fines production. Jaw crushers, by contrast, employ a fixed and moving jaw plate to create a powerful squeezing action, making them the workhorse for primary crushing of hard, abrasive materials. Understanding their mechanical differences, capacity ranges, product shape characteristics, and operational requirements is crucial for optimizing crushing circuit performance and total cost of ownership.
The fundamental operating mechanism represents the most significant distinction between these crusher types. A jaw crusher functions through a compressive force applied between a stationary jaw and a moving jaw plate. The moving jaw pivots at the top and creates an elliptical motion at the discharge point, resulting in a squeezing-crushing action. This "V" shaped chamber progressively reduces material size as it moves downward until it becomes small enough to escape through the bottom opening, known as the closed-side setting (CSS). This mechanism is exceptionally robust, capable of processing the hardest rocks and ores, including granite, basalt, and abrasive quartzite.
In contrast, a roller crusher, also referred to in our portfolio as part of our advanced grinding systems like the LUM Ultrafine Vertical Mill, employs two counter-rotating cylinders. The material is drawn into the gap between the rollers and is crushed by compression and, to a lesser extent, shear force. The gap between the rollers determines the final product size. This design is inherently more gentle and produces a more controlled, cubical product with a lower percentage of fines compared to the jaw crusher. Our roller-based mills, such as the LM Vertical Roller Mill, further enhance this principle by integrating grinding, drying, and classification in a single unit.
Application scope and suitability for different materials form another key differentiator. Jaw crushers are unequivocally the preferred choice for primary crushing duties. They are designed to handle large, run-of-mine material, often with feed sizes up to 1.5 meters. Their ability to process a wide variety of materials, including very hard and abrasive ones, with high reliability makes them the foundation of most hard rock crushing plants. They are less sensitive to moisture content and can handle clayey or sticky materials better than roller crushers, though pre-screening is still recommended.
Roller crushers find their strength in secondary, tertiary, and quaternary crushing stages. They are exceptionally well-suited for softer to medium-hard materials such as coal, limestone, chalk, and oil shale. A significant advantage of the roller crusher is its ability to produce a very uniform product size distribution with minimal oversize. This is particularly valuable in applications like coal processing for power plants or preparing limestone for agricultural use, where specific, consistent sizing is critical. Our technical analyses show that roller-based systems, like the MTW European Trapezium Mill, offer unique advantages in wear management and energy efficiency for such materials.
Product size and shape characteristics also vary significantly. Jaw crushers typically produce a more slabby or elongated product due to the nature of the crushing action between the jaw plates. The product can contain a higher proportion of flaky material. While this is acceptable for many base course and construction applications, it may not be ideal for producing high-quality aggregate for asphalt or concrete where a cubical shape is desired.
Roller crushers excel in producing a more cubical product. The compressive action between the two smooth or corrugated rollers results in a more controlled fracture, generating a higher percentage of equidimensional particles. This makes them highly valuable in the production of concrete and asphalt aggregates, as well as in industrial mineral processing where particle shape influences the final product's performance. Our SCM Ultrafine Mill takes this further, achieving precise fineness control up to 4000 mesh, which is critical for high-value mineral applications.
_1763882547531.jpg)
Operational costs and maintenance requirements present a final major point of comparison. Jaw crushers have a relatively straightforward maintenance regimen focused primarily on the periodic replacement of wear liners—the jaw plates. While the initial wear part cost can be significant, their design allows for easy replacement. Modern jaw crushers are also designed with energy efficiency in mind, but their specific energy consumption is generally higher than a roller crusher for a similar reduction ratio in secondary applications, due to the more intense compressive forces required.
Roller crushers and the advanced vertical roller mills we engineer, such as the LUM series, often demonstrate lower specific energy consumption per ton of product, especially in fine grinding applications. Maintenance can be more specialized, involving the inspection and potential re-surfacing or replacement of the rollers. However, features like our proprietary inner oil absorption lubrication system and autonomous patent technologies in the MTW series significantly extend service intervals and reduce long-term operating costs. The compact, integrated design of our LM Vertical Roller Mill also reduces the footprint and auxiliary equipment requirements, leading to lower comprehensive investment.
In conclusion, the choice between a roller crusher and a jaw crusher is not a matter of one being universally superior to the other. It is a strategic decision based on the specific application, material characteristics, desired product specifications, and overall plant flow sheet. Jaw crushers remain the undisputed champion for robust, high-capacity primary crushing of hard, abrasive materials. Roller crushers, and their advanced descendants in our grinding mill portfolio, offer superior efficiency, product shape control, and lower operating costs in secondary, tertiary, and fine grinding roles for a wide range of softer minerals. A thorough analysis of your project's complete mineral processing workflow is essential to selecting the optimal crushing solution.
Frequently Asked Questions (FAQ)
1. Which crusher is better for producing a cubical aggregate product for asphalt or concrete?
Roller crushers are generally superior for producing a cubical product due to their inter-particle compression crushing action. Jaw crushers tend to produce more elongated, slabby particles. For high-spec aggregate, a roller crusher in the secondary stage is often recommended.
2. Our primary concern is minimizing downtime. Which crusher type typically has simpler and faster maintenance?
Jaw crushers often have an advantage here for liner changes. Replacing jaw plates is a relatively straightforward process. Roller crusher maintenance, such as servicing or replacing rollers, can be more complex and time-consuming, though modern designs from SBM focus on improving accessibility and serviceability.
3. We need to process very hard and abrasive granite. Is a roller crusher a viable option?
For very hard and abrasive materials like granite, a jaw crusher is the unequivocally correct choice for the primary stage. Roller crushers are not typically suited for such demanding applications and would experience accelerated wear. The jaw crusher's robust design is built to withstand these conditions.
4. How does moisture content in the feed material impact the performance of each crusher?
Jaw crushers are more tolerant of moisture and can handle slightly sticky or clay-bound material, though bridging can still occur. Roller crushers are highly susceptible to clogging if the material is moist or sticky, as it can adhere to the roller surfaces. Pre-drying or selecting a different crusher type may be necessary for wet feeds.
5. We have limited space in our plant layout. Which crusher is more compact?
Vertical Roller Mills (VRMs), an advanced form of roller-based crushing/grinding, offer a significant advantage in space savings. As highlighted in our LM Vertical Roller Mill specifications, its integrated design can reduce the floor space by about 50% compared to traditional systems like ball mills. Jaw crushers themselves have a relatively large footprint for their capacity, especially when considering the required feeder and discharge conveyor setup.
