What are the main factors affecting the service life of broken walls?

As the main wear-resistant component in cone crushers, the service life of the crushing wall is directly related to the equipment's operating rate, maintenance costs, and production continuity. In actual working conditions, the wear rate and failure mode of the fractured wall are often influenced by multiple factors. Understanding these factors can help equipment users take targeted measures, extend the replacement cycle of broken walls, and reduce downtime losses. The following analysis will focus on material characteristics, feeding conditions, the quality of the crushing wall itself, and installation and maintenance.

1、 Material characteristics

The properties of the material itself are the fundamental factors that affect the service life of the crushing wall.

1. Hardness and particle size of materials

The higher the hardness of the material, the greater the stress that the crushing wall bears during compression and impact, and the corresponding increase in surface wear rate. For ores with higher hardness (such as granite, basalt, etc.), the wear per unit tonnage processed by the broken wall is significantly higher than that of medium hardness or soft materials. At the same time, the particle size distribution of materials can also have an impact: when the feed contains a large amount of oversized materials exceeding the specified size, the crushing wall is subjected to concentrated impact in local areas, which can easily lead to early failure.

2. Stone powder content

When the content of stone powder in the material is high, fine particles are prone to form a "buffer layer" in the crushing chamber, weakening the direct crushing effect between materials. At the same time, stone powder may fill between the crushing wall surface and the material, accelerating abrasive wear. In addition, stone powder is more likely to adhere to the surface of the lining plate in humid environments, affecting the crushing efficiency and causing uneven wear.

3. Moisture content

When the moisture content of the material exceeds a certain range (usually considered to be more than 8% to 10%), fine materials will combine with moisture to form viscous substances that adhere to the crushing wall. This not only reduces the fluidity of the material inside the crushing chamber, but may also cause consolidation due to water evaporation after shutdown, increasing the load on the next start-up. Under long-term water containing conditions, the surface of the broken wall may also experience corrosive wear, further shortening its service life.

2、 Feeding conditions

Whether the feeding method is reasonable has a direct impact on the wear uniformity and cumulative wear of the crushing wall.

1. Uniformity of feeding

The design of the cone crusher requires that the material be continuously and evenly distributed on the distribution plate, and fall uniformly along the circumference of the crushing chamber. If the feed is biased towards one side, the crushing wall will remain in a biased state for a long time, bearing uneven extrusion pressure. At this point, the wear on one side of the broken wall is significantly faster than on the other side, resulting in the so-called "eccentric wear" phenomenon. After the occurrence of eccentric wear, the local thickness of the broken wall drops prematurely to the replacement threshold, while other parts can still be used, resulting in a decrease in overall service life.

2. Feed quantity control

When the feeding amount exceeds the capacity of the crusher, there is too much material accumulation in the crushing chamber, and the pressure between the crushing wall and the rolling mill bowl wall remains at a high level, accelerating the fatigue wear and abrasive wear of the lining plate surface. On the contrary, if the feeding amount is too small or intermittent, it will lead to more ineffective impact and sliding friction between the crushing wall and the material, which is also not conducive to prolonging the service life.

3. Composition of feeding particle size

When the proportion of fine-grained materials in the feed is too high, crushing mainly occurs in the lower part of the crushing chamber, resulting in concentrated wear in the lower area of the crushing wall; When the proportion of coarse-grained materials in the feed is too high, crushing mainly occurs in the upper part, causing severe wear on the upper part. Any imbalance in particle size distribution will result in uneven distribution of wear along the height direction of the broken wall, forcing the equipment to be replaced as a whole after local wear meets the standard.

3、 Material and Manufacturing Quality of Broken Walls

The inherent quality of the broken wall itself is the fundamental factor determining its theoretical service life.

1. Material selection

The commonly used high manganese steel (such as Mn13Cr2, Mn18Cr2) has good impact hardening ability. When subjected to sufficient impact strength, a hardened layer will form on its surface to resist wear; But it is suitable for working conditions with sufficient impact load. For fine crushing conditions with relatively limited impact strength, high chromium composite material crushing walls may exhibit more stable wear resistance. Improper material selection, such as using pure high manganese steel lining plates under low impact conditions, will result in insufficient hardening effect and significantly lower service life than expected.

2. Casting process

Broken walls are usually formed using processes such as sand casting, V-casting, or lost foam casting. If there are defects such as porosity, shrinkage, slag inclusion, or cracks during the casting process, these defects will become stress concentration points during service, gradually expanding under alternating loads, ultimately leading to early cracking or local peeling of the fractured wall. A qualified casting process should be combined with appropriate heat treatment (such as water toughening treatment of high manganese steel) to eliminate casting stress and obtain a uniform austenite structure.

3. Surface treatment

Some manufacturers carry out shot blasting strengthening treatment on the broken wall to remove surface oxide scale and form a certain residual compressive stress layer, which helps to delay the initiation of surface microcracks. Untreated broken walls may enter the rapid wear period faster during the initial use stage.

4、 Installation and fastening

The installation quality of the broken wall directly affects its stress state during operation.

1. Coordination gap and fixing method

After the broken wall is installed on the body, it needs to be filled with zinc alloy or epoxy resin between the two to ensure a tight fit. If the filler casting is insufficient or there are voids, relative micro motion will occur during the operation of the broken wall, resulting in wear and loosening of the mating surface. The loosened broken wall will experience additional impact and displacement inside the crushing chamber, accelerating the damage.

2. Fastener status

The broken wall is fixed to the body through components such as conical heads, pressure sleeves, and locking nuts. Insufficient pre tightening force during installation or loosening of the locking device due to vibration during operation can cause the broken wall to loosen. According to engineering experience, insufficient preload may cause loosening, while excessive preload (such as exceeding a specific value of 40 tons) may increase the risk of wall fracture. Therefore, tightening should be carried out according to the parameters specified in the equipment manual.

3. Mixing old and new parts

When replacing the crushing wall, if the wear of the grinding bowl wall, adjusting the ring thread, and balancing guard plate is not checked synchronously, there may be a mismatch between the new crushing wall and the old grinding bowl wall, which may also cause changes in the shape of the crushing chamber, artificially causing excessive local load and shortening the service life of the new crushing wall.

5、 Operation and maintenance factors

The daily management and maintenance behavior of operators also have an impact on the lifespan of broken walls.

1. Idle time

The cone crusher runs idle for more than the specified time without any material (usually recommended not to exceed 30 minutes), and there is no material buffer between the crushing wall and the rolling mill wall, resulting in direct contact and possible metal impact and additional friction, causing unnecessary losses.

2. Protection against metal debris

If iron blocks, shovel teeth, or other metal foreign objects are mixed into the feed, these unbreakable hard objects will get stuck in the crushing chamber, causing serious scratches or local crushing on the surface of the crushing wall, and even directly leading to the rupture of the crushing wall. Therefore, it is necessary to install a iron removal device at the feeding end.

3. Regular inspection and adjustment

Checking the wear of the broken wall at reasonable intervals (such as measuring thickness weekly) and arranging replacement when the wear reaches about two-thirds can prevent loosening or cracking caused by excessive wear. Meanwhile, with the wear of the crushing wall, the discharge port gradually increases and needs to be adjusted in a timely manner to maintain the product particle size. Failure to adjust in a timely manner may also lead to changes in subsequent working conditions, indirectly affecting the service life of the lining plate.

6、 The comprehensive impact of working conditions and environment

In addition to the above factors, the environmental conditions of crushing operations (such as ambient temperature, dust concentration, etc.) can also have an impact. The hardening ability of high manganese steel may change under high temperature conditions; Seals are prone to damage under high dust conditions, and dust entering the connection between the spindle and the crushing wall will exacerbate wear. Although these factors do not directly determine the material life of the crushing wall, they indirectly reflect on the wear rate of the crushing wall by affecting the overall operating status of the machine.