The impact of crushing material characteristics (hardness, humidity, size) on equipment selection and efficiency

The impact of crushing material characteristics (hardness, humidity, size) on equipment selection and efficiency

When choosing a crusher and predicting its working efficiency, the first task is not just to look at the equipment parameters, but to have a deep understanding of the characteristics of the material you want to process. The hardness, moisture content and initial size of the material together determine which equipment is most suitable and energy efficient, as well as the challenges that may be encountered during operation. It can be said that material characteristics are the “first drawing” for equipment selection.

First of all, the hardness and abrasiveness of the material are the most decisive factors.

Impact on selection:

High-hardness, highly abrasive materials (such as granite, basalt, quartz stone): Equipment with extrusion and impact as the main crushing principles must be selected, such as jaw crushers (for coarse crushing) and cone crushers (for medium and fine crushing). Their structure is strong and the wear parts are made of special materials that can withstand huge pressure and wear. Avoid using equipment that mainly relies on hitting and grinding (such as ordinary hammer breakers), otherwise the wear will be extremely rapid.

Medium to low hardness, low abrasive materials (such as limestone, gypsum, coal): a wider range of choices. Impact crushers and hammer crushers are ideal because of their high efficiency, low energy consumption and the ability to produce products with good particle shape.

Impact on efficiency: The harder the material, the greater the energy required for crushing, the faster the equipment wears, the lower the efficiency, and the higher the operating cost (power consumption, replacement of wearing parts).

Secondly, the humidity and viscosity of the material directly affect the crushing process and equipment smoothness.

Impact on selection and operation:

Dry Materials: Almost all types of crushers work well.

High moisture, clay-containing or sticky materials: these are common problems in crushing operations. This kind of material is easy to adhere and block in the crushing cavity, screen plate and feeding funnel, causing a sharp decrease in production capacity or even complete shutdown.

Countermeasures: It is necessary to use specially designed equipment, such as a hammer crusher without screen plate or adjustable gap, or adopt processes such as pre-drying and reducing the feeding speed. When the humidity is too high, you may need to consider drying pretreatment.

Impact on efficiency: Wet and sticky materials will seriously reduce the pass rate and effective working time, increase the frequency of maintenance and cleaning, and greatly reduce the overall efficiency.

Finally, the initial size of the material (feed particle size) is the key to matching the equipment specifications.

Impact on selection:

Large pieces of material (more than half a meter or even one meter in diameter or side length): The first "coarse crushing" must be carried out with a jaw crusher to reduce its size to the "feed opening size" range that can be accepted by subsequent equipment (such as impact crusher, cone crusher). Large pieces of material cannot be fed directly into equipment designed for medium crushing.

Medium and small materials: You can directly choose impact crusher, cone crusher or hammer crusher for medium and fine crushing according to other characteristics (hardness, product requirements).

Impact on efficiency: The efficiency is highest when the feed size matches the equipment feed inlet. If the feed is too large, it will easily cause blockage and machine jamming; if the feed is too small, it may cause the equipment to "chew on empty", failing to give full play to its crushing capacity and wasting energy.

Summary and suggestions:

Before selection, be sure to sample and analyze the materials. Identify whether it is hard or soft, dry or sticky, large or small. A simple decision logic is:

Facing large pieces of hard rock, take the route of "jaw crushing (coarse crushing) → cone crushing (medium and fine crushing)".

When facing small and medium-sized pieces of medium-hard materials and pursuing good particle shape, impact crushing is the first choice.

In the face of sticky and wet materials, focus on the anti-clogging design of the equipment.

Ignoring material characteristics and making choices based only on equipment price or a single output parameter are the most common reasons for project failure and runaway cost control. Providing your material samples and characterization to equipment suppliers is a necessary step to obtain accurate recommendations.