Product size is the main process index to measure the quality of stone products. The construction industry has higher requirements on the product size of stone than the mining industry, especially in the concrete aggregate, the increase of needle and flake will lead to the decrease of the overall compressive strength of the building, and increase the cement consumption in the construction process.

Many people think that the product particle size is not as good as the impact breaking, and the content of needle and flake products is high. What are the factors that affect the particle size of the product for conical fracture? How to improve the product granularity?

1. Effect of stroke on particle size

The stroke is the distance from the loose side discharge port to the tight side discharge port of the cone crusher. For the convenience of explanation, two different strokes of single cylinder hydraulic cone crusher are used to crush the same stone, and the finished products are compared. The specific data are shown in the following figure:

It can be seen from the figure above that the stroke has an effect on the particle size of the product. In the cone crusher, the stroke size depends on the eccentric angle. The eccentric angle of single cylinder hydraulic cone crusher can be adjusted according to the actual demand. The method is that the eccentricity angle is composed of an eccentric copper sleeve with multiple keyways and an eccentric sleeve. By rotating the eccentric copper sleeve corresponding to different keyways, different eccentricity angles can be formed. In this way, multiple strokes of 18mm, 25mm and 32mm can be obtained (the adjustment methods of different products are different, and the details are subject to various manufacturers, which is for reference only). such According to the different properties of the ore and the appropriate stroke, the particle size of the product can be increased 。

2. Effect of feeding mode on particle size

Uniform circular feeding can not only improve the product particle size and processing capacity, but also make the crushing wall and mortar wall wear evenly and prolong the service life.

In practical use, uniform circular feeding can be realized by distributing tray, and the height between feeding hopper and distributing plate should be adjusted properly. When the height is too high, only a small part of the stone passes through the distributor, which can not achieve uniform circular feeding. When the height is too low, the stone is easy to block and reduce the processing capacity. In addition, the single cylinder hydraulic cone crusher can not only give full play to the capacity of the crusher, but also improve the product particle size.

3. Influence of cavity type on particle size

The single cylinder hydraulic cone crusher uses two kinds of cavity types shown in the figure below. According to the feedback of field use, the improved crushing chamber not only greatly improves the product particle size, but also increases the crusher throughput. The reasons are as follows:

1) Parallel area lengthening

The parallel area is changed from 96mm to 145mm, which increases the crushing times of stone in parallel zone from 1-2 times to 2-3 times. The more crushing times, the better the particle size of the product.

2) The upper half of the crushing chamber is ladder shaped

After the improvement, the mesh angle of the crushing chamber is changed from 22 ° to 16 ° and the decrease of the engagement angle can clamp the larger stone, prevent the stone from jumping upward during crushing, so as to improve the filling rate of the stone in the crushing chamber, thus forming laminated crushing, reducing the needle and flake content of the product stone and increasing the product particle size. Theoretically, if the meshing angle is too large, the ore will slide easily in the crushing chamber, which will reduce the production capacity and increase the wear of lining plate and power consumption; if the meshing angle is too small, the crushing chamber will be too small, and the ore capacity will be relatively reduced, which will affect the output, and at the same time, the manufacturing cost of the equipment and the height of the machine will be increased.

4. Influence of production line on particle size

There are two kinds of layout of the production line: open type production line is from coarse crushing to medium crushing to fine crushing, and there is no return of material; while for closed production line, from coarse crushing to intermediate crushing to fine crushing, some products are returned after screening and then re crushed.

As can be seen from the above figure, the proportion of product granularity produced by closed production line is much higher than that of open production line. The reason is that Increase the number of crushing, can produce better shape, especially fine products more prominent 。

To sum up, through the feedback of on-site use, the appropriate stroke of cone crusher, the appropriate feeding mode and the optimized crushing cavity are selected to crush the stone in the closed stone production line, and the product particle size is effectively improved.