CHOOSING THE RIGHT CRUSHER

What is a Crusher? 

A crusher is a machine that uses mechanical energy to break stones, concrete, or other construction materials into smaller pieces of a specific particle size. They are used especially in the mining industry to reduce the size of ore lumps and facilitate their processing. The crusher is designed to receive chunks of maximum size. Several crushing steps may be required to obtain the desired end product. Shredders are classified according to the fineness of the crushed starting material. There are primary or secondary crushers (coarse finished product) and tertiary or quaternary crushers (fine finished product).

How to choose the right crusher?

There are several factors to consider:

1. Abrasiveness and hardness factors. It is essential to know the material to be crushed, especially its abrasiveness and hardness. 

2. You must evaluate the compressive strength or maximum force the material can withstand before breaking.

3. Size. You need to consider the maximum dimensions (length, width, and thickness) you need to get into the machine.

4. Granularity requirements. It is necessary to define the desired result, i.e. the particle size after crushing.

5. Capacity (throughput). You need to determine how much processing power (or throughput) your use requires. This is measured in tons per hour.

Then you can look at the main technologies of crushers on the market: 1. Jaw Crusher; 2. Cone Crusher; 3. Impact Crusher, also known as Hammer Crusher 4. Shock Crusher

Why Choose a Jaw Crusher?

It is a primary crusher. A jaw crusher is a machine that breaks rock and other hard and abrasive materials such as granite, ore, or recycled concrete, often for industrial purposes. The crushing device consists of a fixed plate and an oscillating plate called the jaw, between which the rock is captured and crushed. A motor and belt transmit the motion to the eccentric shaft, which drives the movable jaw to rotate. The spring resets the movable jaw so that the crushed material will gradually fall into the crusher. When the materials are small enough, they fall into the space between the two jaws of the crusher. The crusher breaks the rock into small stones, especially for making construction and road concrete.

Jaw crushers are basic and reliable technology that doesn't require much maintenance or engineering knowledge. They are the most popular crushers in the world. Jaw crushers are especially suitable when the main goal is to break large pieces into smaller pieces that can then be processed by other machines.

Advantage:

Low maintenance and operating costs due to few moving parts

Reduce raw material to about 150 mm

Shortcoming:

Not suitable for small material requirements (less than 150mm). If a smaller particle size is required, it can be combined with other crushers.

Not suitable for handling clay or metal mixed with rock.

Why Choose a Cone Crusher?

Cone crushers, also known as cone crushers, break rock between an eccentric rotating head and a bowl. The swivel head is covered with a wear-resistant cover. Large pieces are crushed once between the two jaws, and then gradually descend into the crusher to continue crushing until the pieces are small enough to pass through the narrow opening at the bottom of the crushing space. Cone crushers can crush a variety of rocks from medium to hard. A cone crusher works in a similar way to a gyratory crusher, but in a cone crusher, the crushing space does not have as steep a slope.

Although cone crushers are known for their ability to crush hard, abrasive ores and rocks, cone crushers are better suited for secondary crushing. It is designed to crush material of a predetermined size, typically 100mm, 150mm, or 200mm, and to deliver finished products in small sizes.

Advantage:

Sturdy structure; High productivity; Easy to adjust; Low operating costs This type of crusher is equipped with a spring release system that prevents overloading and allows uncrushable material to pass through the crushing space without damaging the crusher; Machines are cheap.

Shortcoming:

Cone crushers cannot handle all sizes of material. The size of the material (typically 200 mm or less) must be predetermined for the crusher. The finished product is not uniform, which is a basic requirement of many material specifications.

Not suitable for handling clay or metal mixed with rock.

Why choose an impact crusher?

Depending on size and technology, impact crushers can be used as primary, secondary, or tertiary crushers. They are equipped with agitators (also known as hammers) and impact plates. They work as follows: they are fed from above, and then the stones are hammered and projected towards the slab. The stone breaks on the board and bounces back onto the hammer. Repeat the process until the stone is the desired size. Impact crushers are ideal for mixing materials. They can pulverize clay, dirt, or metal mixed with the feed, such as rebar, wire mesh, or anchors. They can crush hard material but are especially good for soft to moderate rock. Impact crushers, also known as hammer crushers, can have horizontal or vertical axes.

Horizontal axis: Generates a uniform cubic product. It accepts all feed inputs and ensures maximum productivity for primary and secondary crushing.

Advantage:

The impact force allows better control over the size of the crushing results, e.g. better cubic gravel.

Shortcoming:

Operating costs may be higher.

It can be difficult to break small parts because the ability of the crusher to break blocks is related to the energy accumulated when the stone hits the hammer. So this energy depends on the speed of the hammer, but also on the mass of the stone.

Agitator wear depends on the material being pulverized.

Vertical axis: can produce high-quality sand. It breaks down the gravel finer because it breaks the most durable bonds in the aggregate. This gives the sand the optimum consistency and shape, especially for concrete. The machine combines rotational and impact energy for crushing.

Advantage:

high productivity;

High breakage rate;

Low energy consumption;

Uniform particle size.

Shortcoming:

Can only be used to obtain beautiful finished products

What are other important factors to consider when choosing a crusher?

While stationary crushers have the advantage of being robust, opting for a mobile crusher can bring the crusher closer to where it is needed. The wheeled crusher can be moved to the construction site using a truck. These units are usually autonomous and therefore do not require an additional diesel engine to operate. Track-type crushers are designed to be constantly moving. They are more compact and lighter than mobile wheel crushers.

Mobile crushers perform the same types of crushing as stationary crushers. For reasons of autonomy, they also include a hopper and a conveyor feeding the crusher, as well as a second conveyor for discharging the final product. With the use of mobile screening machines, customers will get the most satisfactory finished products.