Secondary crusher

Types of secondary crushers

The primary function of secondary crushers is to further reduce materials that primary crushers have already processed. Different kinds of crushers are available to fulfill this purpose.

• Gyratory crusher

  Gyratory crushers have an internal shaft and a concave surface. The material to be crushed enters between the two pieces. As the inner shaft rotates, it moves upward, compressing the material and pushing it downwards. The movement resembles a cone or an upside-down V. This movement is what crushes the material. Gyratory crushers can take large amounts of material and produce high capacities. However, they need a lot of space to work.

• Roller crusher

  A roll crusher functions quite similarly to a gyratory crusher. It consists of two horizontal cylindrical rollers. The material is crushed between them as the two cylinders rotate in opposite directions. Often, roller crushers are installed after primary crushers and before tertiary crushers. Their produce size is coarser than that of secondary crushers and finer than that of primary crushers.

• Impact crusher

  Impact crushers break rocks or other materials by hitting them with a blow bar. The blow bars are usually made of high chrome. The high speed at which they rotate makes them hit the material with a strong force, breaking it. Other parts of an impact crusher include the impact plates and the outer shell or housing. Once the material is processed, it goes through another process called grading, whereby a classifier determines its size. Smaller materials exit the impact crusher, while larger ones go through further crushing.

• Cone crusher

  A cone crusher looks like an ice cream cone. It has a bowl-shaped outer container and a conical inner part that fits inside the bowl. The material drops between the two parts. The inner conical part moves up and down, crushing the material in the process.

Specifications & Maintenance of Secondary Crushers

Specifications

• Capacity: Depending upon the type and model of the secondary crusher, its capacity will differ. It is usually given in tons per hour (TPH).
• Power Consumption: The power that is consumed by the crusher also varies according to its capacity. This is given in kilowatts per hour (kWh) and depends upon the material being crushed, its hardness, and the capacity of the machine.
• Dimensional Specs: The dimensions of a secondary crusher differ with the models. It includes width, length, and height.
• Cutting Mechanism: Whether it is a cone, impact, or any other type of secondary crushing machine, each one will have its own cutting mechanism or technology. The type of cutting mechanism will also determine its efficiency and output quality.

Note: Apart from these key specifications, there are many more details about a secondary crusher, like its type, shape, blade material, etc. that buyers can check while placing their orders.

Maintenance

Like any other industrial machinery, it is important to maintain the crusher so that it functions effectively. If proper maintenance is done, it can help extend the life of the machine and also reduce any unforeseen downtime caused by accidental breakdowns.

• Daily Inspection: A routine visual inspection should be done to check for any abnormal or unusual noises, vibrations, etc. Also, check the tightness of the feed belts and any structural abnormalities of the equipment.
• Lubrication: The manufacturer's guidelines should be followed to ensure proper lubrication of the moving parts. This helps to reduce any friction that may slow down the working of the machine.
• Dust Control: Ensure that the machine is not over and under dusty, as both conditions can affect its operations. Adequate dust control measures should be taken to prevent any clogging or pollutant buildup. At the same time, protect pollutants and employees from becoming exposed to dusty situations.
• Replace Worn Parts: Regularly check for any worn or damaged parts that may need to be replaced. Keeping a part of the secondary crusher in mind helps to ensure smooth and efficient functioning.

Scenarios of the secondary crusher

Because of its ability to produce smaller-sized stones, the secondary stone breaker machine is still in great demand in the construction sector of both developing and developed countries. According to a report published in September 2021 by Mordor Intelligence, the global stone crushing equipment market was valued at 2.3 billion in 2020 and is expected to reach 3.4 billion by 2026, with a CAGR of 6.1% during the forecast period.

One of the main use scenarios of secondary crushers is in the mining sector, wherein valuable minerals like gold, copper, diamond, etc., are encased within large boulders of rock. Large primary crushers may not be sufficient to access these minerals, and therefore, secondary crushers become vital in fragmenting these rocks further to expose the valuable mineral. Once exposed, primary crushers may again be used to access that specific area containing the mineral.

In aggregate production for the construction industry, secondary crushers play a vital part by reducing larger rock fragments into gravel and smaller stone pieces that are necessary for asphalt and concrete production. This is one of the most significant functions of secondary crushers, and they are, therefore, an integral part of quarry operations.

Landscaping projects require smaller stone pieces to be utilized to create pathways, as base material, or even to create drainage areas within the landscaping project. Smaller-sized stone fragments that secondary crushers produce are ideal for such home improvement projects.

Furthermore, secondary crushers are also used to produce back-fill and sub-base materials for tunneling projects. The stone sizes produced by secondary crushers are ideal for creating a solid foundation for tunnels as well as roads.

Cement and concrete companies also utilize secondary crushers to produce the smaller sized stone aggregate that is mixed with cement to provide strength to the final product. Moreover, secondary crushers are also used to produce sand when tertiary crushers are not used.

How to choose secondary crushers

When choosing the suitable secondary crushers for a specific application, there are a few critical things to consider. First, think about the materials that will be crushed. What kind of rock is it? What is its size? What is its shape? Go for the secondary crusher that is designed to handle the specific type of material. For example, cone crushers are better for hard, abrasive rocks, while impact crushers suit softer, less dense materials.

Next, consider the desired output size and capacity. Different secondary crushers produce different sizes of crushed rock. Make sure to choose one that can achieve the required gradation. At the same time, check that its processing capacity matches the project's demands. A small crusher may bottleneck the entire operation. On the other hand, a large one could consume excess power and yield more fines than needed.

Additionally, evaluate design features such as safety mechanisms, adjustment methods, and accessibility for maintenance. Are the parts that need regular service easy to reach? Do safety guards cover all rotating components? Can operators quickly adjust settings if product specifications change?

Finally, compare costs between various options. Analyze the total cost of ownership by factoring in fuel consumption, spare parts availability, warranty, reputation of the manufacturer, etc. More expensive models with better efficiency and lower maintenance requirements may provide savings in the long run.

Secondary Crusher Q & A

Q1: What is the difference between a primary and secondary crusher?

A1: The primary crusher breaks the large raw material into smaller chunks. Secondary crushers take those small chunks and break them down further into smaller particles.

Q2: What type of motor is used in a secondary stone crusher?

A2: Generally, secondary crushers use a 75 kW motor, but this may vary depending upon the specific type of crusher and its size.

Q3: What are the latest advancements in secondary crushers?

A3: There is a growing trend towards automation and smart technologies in the crushing sector, leading to the development of intelligent secondary crushers with automated control systems.

Q4: What are the biggest challenges faced by secondary crushers?

A4: The main challenges include dealing with variable feed material characteristics, maintaining product size distribution, operational efficiency, and the need for timely maintenance to prevent downtimes.