Cone Crusher Liners

In today’s economic climate, cost reduction and profit maximization are paramount. Successfully managing a quarrying business involves strategic cost considerations, particularly in addressing significant expenses such as cone crusher replacements.

This article introduces a cost-effective approach to minimizing crusher replacement costs through the use of cast crusher liners. Recent advancements in this method have proven its effectiveness when applied in suitable scenarios. Cone crushers function by feeding stone into the top of the crusher chamber.

The chamber is equipped with crusher replacement lining, specifically the mantle and bowl liners. As the stone descends, it breaks due to the pressure and friction generated by the movement of the mantle and bowl liner.

The liners vary manganese content depending on the type of stone being crushed, ranging from 12% to 23%, resulting in materials labeled Mn14, Mn18, and Mn21.

Liner Selection

Crucial to crusher selection is the type of bowl liner:

• Coarse: featuring a wide inlet aperture
• Medium: with a medium inlet aperture
• Fine: designed with a small inlet aperture

Selection depends on the desired product and feedstock, emphasizing the importance of consulting manufacturers. Some offer computer-aided design services and wear-analysis for various crushers, including those of competitors.

Crusher Selection

Optimal crushing chamber selection is pivotal during cone crusher installation. The reduction ratio, determining the produced product, relies on the chosen chamber. Moreover, the closed-side setting, influencing both wear and the final product, requires consideration. Choosing a standard unit over a short head reduces fine product output, leading to recirculation and increased wear.

Chamber Characteristics:

• Standard: shallower angle, longer crushing face, suitable for larger feed sizes
• Shorthead: steeper angle, shorter crushing face, suitable for smaller feed sizes

Adding Protective Surface

To prevent early liner wear, experts apply a protective coating on the liners. Manganese liners may change shape and size over time, impacting the crusher’s fit. Precise application is crucial, and minor distortions with backing compounds are manageable.

The protective coating process involves placing the liner on a rotating turntable, preheating it, and applying a 3mm-thick chrome carbide bead. Wear patterns dictate treatment areas, and researchers experiment with various treatments to observe their impact on liners.

Exceeding the intended operating life of cone crusher liners can lead to detrimental mechanical issues. Prolonged use causes liners to flex, crack, and thin or cracked mantles may result in severe seat surface damage. While determining worn-out liners lacks foolproof methods, three key indicators signal the need for replacement:

1. Production Level: A 10% or more drop in production level signals the timely replacement of Cone Crusher liners.
2. Liner Thickness: If liners wear uniformly to about 1” (2.5 cm) at the bottom, consider replacement. At 3/4” to 5/8” (1.9 cm to 1.6 cm), liners may crack, causing disintegration of the backing material. Loose liners risk damaging the support bowl or cone crusher head. Some models feature an automatic reminder resetting with new mantle and concave liners. The system tracks production and calculates wear rates, flashing a “Change Cone” reminder when reaching maximum wear.Note: Never pair new concave liners with a worn mantle, or vice versa, altering the crushing chamber profile and reducing hourly production.
3. Proactive Replacement: Change liners before significant production losses occur. On top-adjust/screw adjust cones, feed size dramatically shrinks in the last 1/3 of life, with potential 30% feed size loss. Hydrocones maintain constant feed size. Accurate belt scales help predict the decline, allowing timely scheduling.Threshold for Change: Change liners no later than a 10% decline in production. A 10% reduction, for example, results in a $2,000 daily gross profit loss, accumulating substantial losses over weeks. Delaying changes, despite tough times, adds unnecessary operational hours, wages, and fuel costs.

In essence, efficient cone crusher operation demands proactive liner replacement. Monitoring production, assessing liner thickness, and adhering to a 10% decline threshold ensure optimal performance, preventing significant financial losses and maximizing crusher efficiency.

Typically, the process of changing cone crusher liners involves six steps:

1. On the initial installation of new liners, mark the adjustment cap driver ring where the pinion tooth aligns with a driver ring tooth upon achieving the desired crusher setting.
2. Maintain a precise record of the number of teeth utilized to compensate for liner wear during this initial set of liners.
3. After the first set of liners has worn out, but before moving the bowl, document the total number of teeth the driver ring has moved and apply a straight line on the side of the dust cover just below the adjustment cap. This line serves as a reference point for gauging the proximity of the next liner sets to wear.
4. Upon the installation of a new liner set, track the number of teeth the driver ring has moved and compare this figure with the total from the first set of liners. This comparative analysis provides an assessment of liner wear.
5. The horizontal mark painted on the dust cover will also signal when the liners are approaching the wear limit. This serves as an additional indicator for wear assessment.
6. Refer to the attached tables for approximate minimum heights of the adjustment cap (A-dimension) with worn liners. These tables offer essential guidelines for evaluating liner wear during the replacement process.

Selecting the appropriate crushing chamber involves considering five crucial factors:

1. Feed Size: Each chamber configuration has a maximum feed size it can accommodate, making it imperative to match the chamber to the feed size.
2. Feed Grading: The maximum feed size is critical, especially if the feed contains fines or a single size, as it can impact wear and output. Attention to recirculating stone is vital due to its increased abrasiveness and hardness compared to virgin stone, potentially causing issues with segregated feed.
3. Output Required: Consideration of the desired output and grading influences the selection of the crushing chamber based on specific requirements.
4. Crusher Adjustment (CSS – Closed Side Setting): CSS, defining the reduction ratio in cone crushers, significantly affects product gradation, capacity, and power draw. Measured from the bottom of the mantle to the bottom of the bowl liner at their closest point during the gyrating cycle, CSS should closely match the required product. A too-small setting is indicated if the adjustment ring moves on the mainframe.
5. Crusher Operating Speed (RPM): Higher speeds generally result in a finer product gradation curve and improved product shape, crucial for most construction applications. Operating the cone crusher at the lower end of its speed range increases cavity volumetric throughput, altering the product gradation curve to produce fewer fines. Adjusting the crusher operating speed involves changing the diameter of the crusher and motor sheaves.

It’s worth noting that each cone crusher offers various cavity options with different feed openings and setting ranges. Choosing the correct cavity depends on factors such as feed size, setting, and application. Importantly, the crusher is just one component of a crushing circuit. Its performance hinges on the proper selection and operation of feeders, conveyors, screens, electric motors, drive components, and feed silos—all integral parts of the circuit. To optimize production, it’s essential to evaluate these elements collectively.

Typically, the production of cone crusher liners involves a sand casting process, following standard steps outlined below:

1. Review and Translation: Begin by checking and translating customer drawings to ensure accurate representation.
2. Prototype Generation: Develop a prototype of the product for enhanced comprehension.
3. Design and Documentation: Engineers create a detailed design and produce documents specifying crucial details such as heat treatment temperature, time, casting temperature, casting duration, and temperature maintenance time.
4. Model Creation: Construct product models, including steel and wood pattern models.
5. Raw Material Preparation: Initiate the preparation and analysis of the raw materials.
6. Casting Process: Utilize a bottom pour ladle to cast the products.
7. Post-Casting Procedures: After a cooling period, remove gating and risers, preparing the goods for the heat treatment phase.
8. Machining: Perform machining processes on the cone crusher liners.
9. Printing and Packaging: Conclude the production cycle with printing and packaging of the final product.