How can a mineral sizer be adjusted for different types of material

Introduce

The unique structural design of the Mineral sizer ensures that the crushing process is forced crushing. Different crushing tooth shapes can be selected according to different feed and product particle size requirements. The crushing teeth are helically arranged on the toothed rolls. The two rolls move relatively like a rotating screen. Materials smaller than the required product particle size pass through smoothly, and only materials larger than the required product particle size are crushed, avoiding the disadvantage of mixed crushing of materials entering the crusher.

The influence of material type on the mineral sizer

Material type and hardness

Material type and hardness are important principles for choosing a crusher. The hardness of different materials varies, and it is usually expressed by the Mohs hardness scale. The Mohs hardness scale is divided into 10 levels. The higher the Mohs hardness number, the harder the mineral, and the greater the difficulty of crushing. Conversely, the lower the number, the easier it is to crush.

Soft materials

such as coal, gypsum, etc. These materials have low hardness and relatively high brittleness. During the crushing process, they are prone to being compressed and split, but excessive crushing may result in too much powder, which will affect subsequent screening and the process flow. Therefore, for soft materials, the key lies in precisely controlling the degree of crushing to avoid unnecessary energy consumption and the generation of fine powder.

Medium-hard materials

Such as limestone and slag, have certain toughness and hardness. During crushing, not only a large crushing force is needed to overcome the strength of the materials, but also the fluidity of the materials between the toothed rollers needs to be considered to prevent blockage. Medium-hard materials cause more obvious wear on the toothed rollers, and it is necessary to ensure the crushing effect while also taking into account the wear resistance and service life of the mineral sizer.

Hard materials

such as iron ore, coke, etc., have high hardness and strong toughness, and are difficult to break. These materials place higher demands on the crushing force of the crusher, the strength of the tooth rollers, and the design of the tooth shape. When crushing hard materials, if the mineral sizer parameters are improperly configured, problems such as tooth roller damage, low crushing efficiency, and even mineral sizer failure may occur.

The moisture content of the materials

The moisture content of the materials also affects the selection of the crusher. When the moisture content is too high, fine-grained materials will form clumps or stick to the coarse-grained materials due to the increase in humidity, thereby increasing the viscosity of the materials and reducing the ore discharge speed, resulting in a decrease in productivity. In severe cases, it may even cause blockage of the ore discharge port, affecting the normal operation of production.

The degree of cleavage development of the ore

The degree of cleavage development of the ore also directly affects the productivity of the crusher – when the ore is being crushed, it is prone to break along the cleavage plane. Therefore, when crushing the ore with a developed cleavage, the productivity of the crusher is much higher than that of crushing the ore with a dense structure.

Feed and discharge particle size

If the proportion of coarse particles (larger than the discharge opening size) in the crushed materials is high or the ratio of the largest piece of the feed to the width of the feed is large, the crushing ratio that the crusher needs to achieve (the ratio of the particle size of the material before crushing to the particle size of the material after crushing) is large, so the production rate decreases;

If the proportion of fine particles (close to or smaller than the discharge opening size) in the crushed materials is high or the ratio of the largest piece of the feed to the width of the feed is small, then the required crushing ratio is small, so the production rate is correspondingly increased.

Adjustment strategies for mineral sizers for different types of materials

Gear Design and Optimization

The gear shape is the key part where the double-disk roller crusher comes into direct contact with the materials and performs the crushing process. For materials of different hardness, different gear designs should be adopted.

For soft materials

For soft materials, a larger pitch and higher tooth height can be adopted. A larger pitch can reduce the frequency of contact between the material and the tooth roller, thereby lowering the risk of excessive crushing; a higher tooth height helps to increase the time that the material is subjected to compression and splitting between the tooth rollers, thereby improving the crushing efficiency.

For medium-hard materials

Medium-hard materials are suitable for a medium pitch and moderate tooth height. Such a tooth shape can provide sufficient crushing force while ensuring the smooth passage of the material between the tooth rollers, reducing the occurrence of blockages.

For hard materials

For hard materials, a smaller pitch and lower tooth height are required. A smaller pitch can increase the number of bites between the tooth roller and the material, enhancing the crushing capacity; a lower tooth height can reduce the force on a single tooth, improving the impact resistance of the tooth roller. When crushing iron ore, this tooth shape helps to penetrate the surface of the material, achieving effective crushing, and reducing the wear and damage of the tooth roller.

Adjustment of gear roller gap

The gap between the gear rollers is an important parameter affecting the crushing effect of the mineral sizer. It can be flexibly adjusted according to the hardness of the material.

Crushing soft materials

When crushing soft materials, the gap between the gear rollers should be appropriately increased. Since soft materials are prone to breakage, a larger gap can prevent excessive crushing of the materials, while allowing some larger uncompletely crushed pieces to pass through, avoiding the formation of over-crushing and ensuring the uniformity of the product size.

Crushing medium-hard materials

When crushing medium-hard materials, it is necessary to precisely control the gap between the toothed rollers. If the gap is too large, it may result in insufficient material crushing, affecting product quality; if the gap is too small, it is prone to cause blockages and mineral sizer overload.

By reasonably adjusting the gap, the material can be moderately compressed and crushed between the toothed rollers, which can not only ensure the crushing effect but also maintain the stable operation of the mineral sizer.

During the limestone crushing process, by timely adjusting the gap according to the changes in the particle size and hardness of the limestone, the crushing efficiency and product quality can be effectively improved.

Crushing hard materials

When crushing hard materials, the gap between the toothed rollers should be reduced. A smaller gap can increase the crushing force and ensure effective crushing of hard materials. However, it is also necessary to be cautious to prevent the gap from being too small, which could lead to excessive load on the mineral sizer and excessive wear of the toothed rollers.

When crushing hard materials such as iron ore, by precisely adjusting the gap between the toothed rollers, the service life of the mineral sizer can be extended while ensuring the crushing effect.

Matching of rotational speed and crushing force

The rotational speed and crushing force of the Mineral sizer directly affect the crushing effect of the materials and the operational performance of the mineral sizer. They need to be reasonably matched according to the hardness of the materials.

Soft materials

When crushing soft materials, a relatively lower rotational speed and moderate crushing force can be adopted. The lower rotational speed can reduce the collision and impact between the materials and the toothed rollers, avoiding the generation of excessive powder; the moderate crushing force is sufficient to cause the soft materials to break under the compression and splitting effects, while also reducing energy consumption.

Medium-hard materials

When crushing medium-hard materials, it is necessary to appropriately increase the rotational speed and enhance the crushing force. A higher rotational speed can increase the movement speed of the materials between the tooth rollers, thereby improving the crushing efficiency; increasing the crushing force can overcome the strength of medium-hard materials and achieve effective crushing.

However, it is important to avoid excessive speed that causes the materials to become too dispersed, which would affect the crushing effect and the stability of the mineral sizer. During the limestone crushing process, by adjusting the rotational speed and crushing force, the limestone can reach the required crushing particle size within a short period of time while ensuring the normal operation of the mineral sizer.

Hard materials

When crushing hard materials, a high rotational speed and strong crushing force should be adopted. The high rotational speed can enhance the impact and shearing effect of the toothed rollers on the hard materials, while the strong crushing force can ensure that the hard materials are fully crushed between the toothed rollers.

However, high rotational speed and large crushing force also bring problems such as increased wear of the mineral sizer and increased energy consumption. Therefore, it is necessary to comprehensively consider the load-bearing capacity of the mineral sizer and economic benefits.

When crushing hard materials such as iron ore, by optimizing the matching of rotational speed and crushing force, it is possible to ensure the crushing effect while minimizing the mineral sizer’s wear and operating costs.

Advantages and features of the mineral sizer:

It has both crushing and screening functions.

The special structural design of the mineral sizer ensures that the crushing process is forced crushing, and different crushing tooth shapes can be selected according to different feed materials and product particle size requirements.

The crushing teeth are spirally arranged on the tooth roller, and the two rollers move relative to each other like a rotating sieve. Materials smaller than the product particle size requirements pass smoothly, and only materials larger than the product particle size requirements are crushed, avoiding the drawback of mixed materials entering the crusher during crushing.

Strictly ensure product particle size

The mineral sizer generally uses a fixed center distance to forcibly crush the materials. The structural dimensions of the toothed rollers are designed according to the requirements of the product’s degree of affiliation. The space dimensions through which the products pass are strictly controlled, thus ensuring the particle size of the products. It can be used as a particle size control crushing mineral sizer.

Over-crushing and processing capacity

The mineral sizer adopts the principle of shearing. Materials smaller than the required particle size pass directly through, and only materials larger than the particle size requirement are crushed. This avoids the contamination and crushing of materials entering the crusher, thus having an extremely low over-crushing rate.

The teeth are relatively large, and the design of the tooth position and spacing ensures that those particles smaller than the qualified size can pass directly through the crushing section without needing to be crushed, reducing the power consumption for crushing. This unique feature enables it to have a high processing capacity under low rotational speed and low wear conditions.

At the same time, it can also select the rotation direction of the two crushing rollers according to different feed particle size compositions and crushing ratios, increasing the crushing channel and improving the processing capacity.

The structural performance of the mineral sizer

The transmission system adopts a motor + hydraulic coupling + reducer + self-aligning drum-type gear coupling + gear rollers, ensuring the stability and reliability of the mineral sizer operation. It has the advantages of a low overall height, internal balance, and weak vibration.

The structure is compact and lightweight, which can effectively reduce the requirements for the height of the factory building and the bearing strength of the factory building, facilitating the renovation and upgrading of the factory and reducing the capital investment for new factory construction.

Self-cleaning device

When dealing with high moisture content and viscous materials, it is common for the roller teeth to accumulate debris, which affects the crushing efficiency and the lifespan of the mineral sizer. A comb-shaped plate can be installed on both sides of the crushing rollers, made of high-strength wear-resistant alloy steel, with the tooth shape matching the roller tooth groove.

During the operation of the mineral sizer, the loose teeth plate can remove the accumulated debris between the teeth.

Summary

To enable the mineral sizer to better adapt to different types of materials, it is necessary to comprehensively consider factors such as the hardness of the materials, moisture content, degree of cleavage, and the particle size of the incoming and outgoing materials.

Targeted adjustments should be made to parameters such as tooth shape, tooth roller gap, rotational speed, and crushing force. The mineral sizer, with its unique structural design and excellent performance, has demonstrated significant advantages in the crushing operations of different materials.