How to Choose a Rock Crusher

13, May. 2024

 

How to Choose a Rock Crusher

There are several different rock crusher options, and each is used for slightly different purposes. When choosing a rock crusher for your operations, it’s important to first identify the stage of crushing you’re using the machine for. This will determine the appropriate solution for your needs.

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Rock Crushing Stages

There are three different stages of concrete crushing:

  • Primary – This stage involves crushing coarse materials in order to allow them to be transported on a conveyer belt. These machines need to be able to handle a large capacity and accept the raw materials without suffering a blockage.
  • Secondary – In this stage, the coarse materials produced during primary crushing are broken down even more in preparation for final crushing. The purpose of secondary crushing is to achieve the greatest possible reduction in particle size for the lowest possible cost.
  • Tertiary – This stage further refines particles to make them as fine as possible. The quality and quantity of fine products must be considered when determining the right concrete crusher for this phase of the process.

Additional Criteria for Choosing a Rock Crusher

In addition to identifying the proper stage being used with your rock crusher, you should consider the following criteria:

  • Abrasiveness and hardness – What type of material are you trying to crush? You must know the abrasiveness and hardness of the material in order to determine the maximum force or compressive strength the material can withstand before it breaks.
  • Dimensions – You need to identify the maximum length, width and thickness of the materials entering your rock crusher.
  • Granulometric requirement – What grain size are you trying to achieve after crushing is complete?
  • Capacity – You’ll need to determine the processing capacity required for your needs.

 

Rock Crusher Options

Once you’ve evaluated the criteria discussed above, it’s time to choose a rock crusher that will effectively address your specific applications. Each of the following options will deliver different results and are ideally suited to different stages of the process.

 

Jaw Crusher

A jaw crusher is a type of compression crusher that is most commonly used for primary crushing. The material being crushed is squeezed between a stationary piece of steel and a moving piece of steel. This produces the coarsest material since the rock is being crushed along its natural lines of weakness. Jaw crushers are effective the hard and abrasive materials such as granite, ores and recycled concrete.

Advantages of jaw crushers include:

  • Reduces raw materials to a size of 150 mm
  • Maintenance and operating costs are relatively low

Drawbacks to this option include:

    • Not able to produce grain sizes smaller than 150 mm
    • Cannot handle materials that have clay or metal mixed with rock

 

Cone Crushers

As with jaw crushers, these machines are compression crushers that use a stationary and moving piece of steel to break up the material. Cone crushers use a rotating head to crush the rock within a steel bowl. After initially being broken down in this manner, the material will travel through a narrow opening at the bottom of the bowl to achieve a finer grain size.

Cone crushers can be used with a variety of materials, ranging from medium to hard. They are typically used with secondary crushing, especially when the final shape of the crushed material is important.

Advantages of cone crushers include:

  • Easy to adjust
  • High productivity output
  • Sturdy construction
  • Affordable
  • Low operating costs

Drawbacks to this option include:

  • Inability to accommodate materials of all sizes (materials must be 200 mm or smaller before entering the concrete crusher)
  • Inability to produce a homogeneous finished product
  • Cannot handle clay or metal mixed with rock

 

Impact Crushers

Impact crushers break down material by leveraging mass and velocity. The material being crushed is hit by hammers. This material then travels towards a metal plate, where the rock breaks apart and bounces back up to be hit by the hammers again. This process continues until you’ve achieved your desired final size.

Impact crushers can be used with all three stages of crushing. While they can handle materials of all hardness, they are ideally suited for soft to medium rocks.

Advantages of impact crushers include:

  • Greater ability to control the final size of the crushed materials
  • Can accommodate clay, dirt or metal mixed with the rock
  • Produce a more uniform grain size
  • High production capacity

Drawbacks to this option include:

  • Higher operating costs

 

Stationary vs Mobile Jaw Crushers

When purchasing a jaw crusher, you can choose between a stationary option and a portable jaw crusher. Stationary crushers are typically sturdier. However, you’re limited by the fact that it must reside in one place all the time. Mobile jaw crushers, on the other hand, give you the ability to move the machine to the precise location where you need it at all times. For this reason, they often provide a more versatile solution.

Power Screening Can Help

At Power Screening, we have over 35 years of experience providing exceptional quality rock crushers to businesses throughout the Rocky Mountain region. We make customer service a top priority, and this includes making sure you have the right equipment for your specific application. As your dedicated partner, our team will take the time to understand your unique needs in order to ensure you purchase the right equipment to deliver your desired results.

Contact us today to learn about your rock crusher options.

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How Does a Jaw Crusher Work

If you are a rock, sand, gravel, or mineral processing industry veteran or an avid reader of our blog, you know that there are several different types and styles of crushing equipment. The exact crushers you need—jaw, cone, impact, or gyratory—will depend on your site, the product you’re making, and how much you need to produce.

An individual crusher’s construction and capabilities also dictate where in your processing operations it will fit. That is, you may have multiple types of crushers situated in primary, secondary, and tertiary stations in a circuit format to perform the necessary material reduction work. Each type of crusher brings unique strengths and benefits to the process.

Today’s post focuses on compression-style jaw crushers, which are most often employed in the primary stage of a crushing circuit. It’s important to know that cone crushers are sometimes used in their place, and we’ll also talk a little bit about when cone crushers may be preferred over jaw crushers.

What is a Jaw Crusher?

As we introduced in a recent blog post about all the different types of crushing equipment available, jaw crushers are sometimes also referred to as “rock breakers,” which speaks to their brute force. They are almost exclusively used as primary crushers because they excel at breaking up some of the largest and hardest materials into more manageable pieces for further reduction by different crushing equipment. Jaw crushers have a multitude of advantages, including:

  • Can handle many different types of materials—from hard granite to reclaimed asphalt pavement (RAP) and more—without displaying as much wear and tear as primary impact-style crushers.
  • Typically output minimal fine materials and dust.
  • More efficient than primary gyratory crushers.

Due to their smaller physical size, jaw crushers are also ideal for tight spaces, such as underground mining and mobile crushing applications, where some other primary crushing solutions simply do not fit.

Types of Jaw Crushers

Jaw crushers have been around for nearly 200 years at this point and are one of the most “historic” crusher types. Because of this, jaw crushers have advanced technologically through the years to make them more durable and to improve their movement to reduce choking and increase operational speed. These design tweaks over time have perfected a machine that’s simple enough in its working principle that it may never truly become obsolete.

Today, two main jaw crusher configurations are what you will see from the major equipment manufacturers. They differ based on how the swing jaw moves, though their output is similar.

Double Toggle – Blake Type or Overhead Pivot Movement

Double toggle movement jaw crushers like the Blake style (named for the inventor of the first successful mechanical jaw crusher, Eli Whitney Blake), have long been the standard used for crushing hard and abrasive rocks, as well as sticky feeds. These jaw crushers have high energy efficiency. The overhead pivot design further reduces wear and tear on crusher faces versus the Blake style.

Single Toggle – Overhead Eccentric Movement

More compact than double toggle designs, the single toggle movement jaw crusher was at one time unable to accept such large feed sizes, though it can typically run faster. Technological innovations solved the feed size issue, and now these machines are quite popular for how quickly they work. They do experience a bit more wear and tear than the double toggle style crushers, however. Of course, wear parts are widely available and economical, so this fact has not prevented the single toggle design from catching on.

How does a Jaw Crusher work?

As we touched on above, different jaw crusher designs will operate slightly differently, but how they work is similar across the board. All jaw crushers reduce large sized rocks, ore, or other material by a compression action. A fixed jaw, mounted in a V-shaped alignment, is the stationary breaking surface, while a movable, “swing” jaw exerts force on the feed material by pushing it against the stationary plate.

The space at the bottom of the “V”-aligned jaw plates is the output gap that dictates the size of the crushed product from the jaw crusher. The rock remains in the jaws until it is small enough to pass through the gap.

Which are better, Jaw or Cone Crushers?

While jaw crushers may always be a smart primary crusher stage choice for many operations, it’s true that newer cone crushers are increasingly taking their place due to versatility. Cone crushers and jaw crushers both work by compression, reducing materials by squeezing them until they break apart.

The benefit that cone crushers offer over jaw crushers is their ability to output a more cubical product similar to impact crushers. Cone crushers have traditionally been used as secondary and sometimes tertiary crushing stations.

As far as answering whether one type of crusher is better than another, context is key. Everything comes down to what your production needs and goals are.

How can I find the best crushers for my operations?

It’s true that crushers are customizable to help you extract material, break it down into usable product, and get it to market most economically and efficiently. The best way to find the right crushers for your unique operation is to work with a knowledgeable material handling solutions partner like Kemper Equipment. Get in touch with us today to learn how a custom-designed crushing circuit or a few new crushers can boost your productivity and transform your operations.

Want more information on jaw rock crusher? Feel free to contact us.