A Guide to Choosing the Right Primary Crusher for Aggregate Projects

A primary crusher plays an important role in a mineral processing plant. It reduces the size of large rocks wherein the smaller pieces are processed through a number of site components like screens, belts, and secondary crushers to achieve the desired outcome. Almost all of the components at a crush site rely on the primary crusher, making it crucial that you select the right one according to your applications.

These tips will help you identify which type of primary crusher best suits your aggregate projects. We’ll start with the purpose of the equipment, proceed to model refinement, and lastly, install the primary crusher successfully.

Identify the purpose of the primary crusher

The first step in selecting the right primary crusher is to find out its intended use. This precedes the whole decision-making procedure and may require a bit of guidance and experience to get right. The two key components you should determine is the type of material and the feed size to be crushed.

Other factors worth considering are the moisture content of the material, targeted production amount, discharge gradation, and the site’s long-term strategy. Let’s take a look at the different types of primary crushers to better understand their intended use.

Jaw crushers – Jaw crushers are the standard workhorse crushers on most mineral processing plants. It’s comprised of two jaws in a “V” alignment where one side is fixed and the other one moves to compress large rocks and break them into smaller pieces. It’s portable and is easy to relocate into other processing plants when needed. Jaw crushers are ideal for breaking down abrasive materials.

Jaw crushers produce some of the coarsest materials around because the rock gets broken along their natural inherent lines of weakness. This makes jaw crushers an excellent primary crusher for preparing materials for further processing.

Gyratory crushers – Gyratory crushers are ideal for producing large amounts of material (which is usually around 1,000,000 tonnes per annum). These crushers operate on the same principle as with jaw crushers, but instead of a “V” alignment, a circular gap is used. The material is compressed between a fixed conical bowl and an oscillating mantle. Gyratory crushers are perfect for reducing the size of granular rocks like granite and can tolerate a wide variety of feed particles such as slabby rock (which jaw crushers struggle to accept due to the shape of the feed opening).

Impact crushers – Impact crushers work by propelling the fed material against the breaker plates, thus reducing its size. These types of crushers are efficient at processing materials like limestone with better shape than some of the aforementioned crushers.

Impact crushers are used when the shape of the material is a critical requirement. The crushing action breaks the materials along its natural cleavage planes, thus resulting in higher product quality in terms of shape. The only downside is that impact crushers can lead to high wear costs over the long-term.

The capacity of the primary crusher and its ability to accept materials without any blockages are perhaps the most important characteristics of the equipment. Larger primary crushers are generally more expensive, hence investment cost calculations are crucial to find out which sized crusher is needed to blast materials to a smaller size. 

Evaluating the fit and functionality of your chosen primary crusher

Now that you’ve chosen which type of crusher to use, the next step is to evaluate the equipment’s expected performance. This is where simulations come in. Simulations are necessary to determine how the primary crusher will perform and how its performance will affect load downstream. There are a number of software programs out there that simulate the aggregation process which can give you a good idea of the crusher’s real-world performance.

Depending on the results, running a simulation can also affect crusher recommendations. For example, it may be best to use a stationary model as opposed to a portable one if you have long-term plans for the site. From there, a concept drawing is created where it includes details of the crushing site such as grade elevation and the topographical map.

A concept drawing gives you a good idea on how the primary crusher will fit alongside the other components in the site. New primary crushers generally require updates on screens and conveyors to better increase their capacities.

Correct installation of the primary crusher

The last step is to ensure the primary crusher is installed correctly. This process will vary depending on the context and can sometimes prove difficult and confusing. For a successful installation, contact the manufacturer and request their service technicians to assist you during the installation. From the project management down to the performance verification, having an experienced technician to help you out will provide you with added reliability and optimise site configuration right from the start.