What are the structural characteristics of the ball mill?

The material enters the first bin of the mill uniformly by the feeding device through the feeding hollow shaft spiral, which has a stepped lining plate or corrugated lining plate, which is equipped with steel balls of various specifications, and the cylinder rotates to produce centrifugal force to bring the steel balls to a certain height and fall, which has a heavy blow and grinding effect on the materials. After the material reaches coarse grinding in the first bin, it enters the second bin through a single-layer bin plate, which is inlaid with a flat lining plate and has a steel ball in it, and the material is further ground. The powder is discharged through the discharge grate to complete the grinding operation.

In the process of rotation of the cylinder, the grinding body also has the phenomenon of slipping, in the process of sliding to the material to grind, in order to effectively use the grinding effect, the general 20 mesh grinding of the material particle size is larger, the grinding body cylinder is separated into two sections with a partition plate, that is, it becomes a double bin, the material is crushed by the steel ball when it enters the first bin, when the material enters the second bin, the steel section grinds the material, and the material that is fine and qualified is discharged from the hollow shaft at the discharge end, and the material with small feed particles is ground finely, such as sand No. 2 slag, For coarse fly ash, the mill barrel can be made without a partition plate to become a single silo mill, and the grinding body can also be made of steel sections.

In order for the material to be effectively pulverized, the following principles must be followed when determining the gradation:

First of all, the steel ball should have a large enough impact force, so that the ball mill steel ball has enough energy to crush the granular material, which is related to the steel ball, and the steel ball should have enough impact times on the material, which is related to the steel ball filling rate and the average ball diameter. When the filling amount is constant, on the premise of ensuring sufficient impact force, the diameter of the grinding body should be reduced as much as possible, and the number of steel balls should be increased to improve the impact times on the material, so as to improve the crushing efficiency.

Finally, the material has enough residence time in the mill to ensure that the material is fully crushed, which requires the steel ball to have a certain ability to control the flow rate of the material.

The so-called two-stage ball matching method is to use steel balls with two different sizes and large differences in diameter. The rationale is that the gaps between the large balls are filled by small balls to maximize the bulk density of the steel balls. In this way, on the one hand, the impact capacity and impact number of the mill can be improved, which is in line with the functional characteristics of the grinding body, and on the other hand, the higher bulk density can enable the material to get a certain grinding effect.

In the two-stage ball matching, the role of the large ball is mainly to impact and crush the material, and the role of the small ball is to fill the gap between the large balls and improve the bulk density of the grinding body, so as to control the flow rate of the material and increase the grinding capacity; the second is to play the role of energy transfer, transferring the impact energy of the large ball to the material; The third is to squeeze out the coarse-grained materials in the void and place them in the impact area of the large ball.

The ball mill is the key equipment for crushing the material after it is crushed. This type of grinding machine is filled with a certain number of steel balls as grinding medium in its cylinder.

It is widely used in cement, Portland products, new building materials, refractory materials, chemical fertilizers, black and non-ferrous metal beneficiation and glass ceramics and other production industries, dry or wet grinding of various ores and other grinding materials. The ball mill is suitable for grinding all kinds of ores and other materials, and is widely used in mineral processing, building materials and chemical industries, and can be divided into two grinding methods: dry and wet. According to the different discharge methods, it can be divided into two types: lattice type and overflow type.

The ball mill is the key equipment for crushing the material after it is crushed. There are many types of high-fine grinding machinery widely used in industrial production, such as tubular ball mills, rod ball mills, cement ball mills, ultra-fine laminate mills, hand ball mills, horizontal ball mills, ball mill bearings, energy-saving ball mills, overflow ball mills, ceramic ball mills, lattice ball mills. The ball mill is suitable for grinding all kinds of ores and other materials, and is widely used in mineral processing, building materials and chemical industries, and can be divided into two grinding methods: dry and wet.

According to the different discharge methods, it can be divided into two types: lattice type and overflow type. According to the shape of the cylinder, it can be divided into four types: short drum ball mill, long drum ball mill, tube mill and cone mill.

The ball mill is composed of a horizontal cylinder, a hollow shaft and a grinding head for the inlet and outfeed, the cylinder is a long cylinder, the cylinder is equipped with a grinding body, the cylinder is made of steel plate, there is a steel lining plate and the cylinder is fixed, the grinding body is generally a steel ball, and is loaded into the cylinder according to different diameters and a certain proportion, and the grinding body can also be used in steel sections.

According to the particle size of the grinding material to be selected, the material is loaded into the cylinder by the hollow shaft at the feed end of the ball mill, when the ball mill cylinder rotates, the grinding body is attached to the cylinder lining plate due to the action of inertia and centrifugal force, the effect of friction, so that it is attached to the cylinder lining plate and is taken away by the cylinder, when it is brought to a certain height, it is thrown down due to its own gravity, and the falling grinding body crushes the material in the cylinder like a projectile.

The working principle of the tube mill: when the cylinder rotates around the horizontal axis at a certain speed in the tube mill and cement mill, the medium and raw materials installed in the cylinder are under the action of centrifugal force and friction, as the cylinder reaches a certain height, when their own gravity is greater than the centrifugal force, they will fall or roll down from the inner wall of the cylinder, and crush the ore due to the impact force. At the same time, in the process of ball mill rotation, the sliding movement of the grinding medium between each other also has a grinding effect on the raw materials.

Tube mill use: tube mill, cement mill coarse grinding chamber for metal balls or steel rods, the final fine grinding chamber with small balls or steel sections, ore discharge methods are generally lattice type and overflow type, suitable for the cement industry. The ball mill is mainly composed of cylindrical cylinder, end cover, bearing and transmission ring gear and other components, and the cylinder is loaded with steel balls or steel rods with a diameter of 25-150mm, which is called grinding medium, and its loading volume is 25%-50% of the volume of the whole cylinder.

There are end covers at both ends of the cylinder, and the end covers are connected with the end flange of the cylinder by means of screws, and there are holes in the middle of the end cover, which is called the hollow journal, and the hollow journal is supported on the bearing, and the cylinder can rotate. The cylinder body is also fixed with a large gear ring 4.

In the drive system, the motor drives the large gear ring and barrel through the coupling, reducer and pinion, and slowly rotates. When the cylinder rotates, the grinding medium rises to a certain height with the cylinder, and then falls or falls down in a parabolic line. Because there is a hollow journal on the end cover, the material is fed into the cylinder from the hollow journal on the left, and gradually spreads to the right to move, when the material moves from left to right, the rotating cylinder brings the steel ball to a certain height and falls to break the material, and a part of the steel ball has a grinding effect on the material in the state of falling in the cylinder, and the whole moving process is also the crushing process of the material.

In the working principle of the ball mill, due to the rotation of the cylinder and the movement of the grinding medium, the material gradually spreads to the right, and finally discharges from the overflow of the hollow journal on the right, this type of ball mill is called overflow ball mill.

In the first case, as shown in Figure (c), the rotation speed is too high, the centrifugal force makes the steel ball rotate with the cylinder, and the whole steel ball forms a ring close to the inner wall of the cylinder, which is called the "turnover state", and the grinding medium can not impact and grind the material.

In the second case, as shown in Figure (a), the rotation speed is too slow, and the material and the grinding medium rotate along the mill before rising to 40°-50° (there is also a relative slip between the layers during the rise, called slipping), when the friction between the grinding medium and the material and the cylinder is equal to the dynamic friction angle, the friction and the material will slide, which is called the "falling state". It has a grinding effect on the material, but has no impact effect on the material, so that the grinding efficiency is poor.

In the third case, as shown in Figure (b), the mill speed is relatively moderate. After the grinding medium is lifted to a certain height with the cylinder, it leaves the circular track and falls freely along the parabolic money trajectory, which is called the "throwing state", and the steel ball falling along the parabolic trajectory has an impact and grinding effect on the steel ball or cylinder lining plate at the lower part of the cylinder, so that the material is crushed.

Ball mill is the key equipment for crushing after the material is crushed, the equipment is the introduction of mature technology in the industry, combined with the company's other mill production technology and experience, the development of new ball mill equipment, widely used in cement, silicate products, new building materials, refractory materials, fertilizers, ferrous and non-ferrous metal beneficiation and glass ceramics and other production industries, a variety of ores and other grindable materials for dry or wet grinding two ways of grinding. Let's introduce the working principle and characteristics of the ball mill to you:

Performance characteristics:Save energyThere is a matching of the drive and grinding energy consumption, which can greatly save energy consumption.

Turnaround Department

The cylinder, liner, medium, bulkhead plate and discharge grate plate of the rotary part are all composed of high-quality original parts.

High grinding efficiency, liner ***The lining and grinding body are made of alumina ceramic, quartz, silex or special materials, and the hard minerals are designed to be free of iron contamination.

The design of the discharge section is flexibleThe design of the discharge port is reasonable, and customers can choose the iron remover according to their own needs.

The feeding section has a large feed volumeThe reasonable design of the feed port increases the feeding capacity.

Closed system to reduce dustThe ultra-fine ball mill and classifier form a closed system, negative pressure conveying, no dust, and reduce the harm to the human body.

How it works:This machine is a horizontal cylindrical rotating device, outer edge gear transmission, two-bin, lattice type ball mill. The material is uniformly entered into the mill a bin by the feeding device through the feeding hollow shaft spiral, which has a stepped lining plate or corrugated lining plate, which is equipped with steel balls of different specifications, and the cylinder rotates to produce centrifugal force to bring the steel balls to a certain height and fall, which has a heavy impact and grinding effect on the materials.

After the material reaches coarse grinding in the first bin, it enters the second bin through a single-layer partition plate, which is inlaid with a flat lining plate and a steel ball in it to further grind the material. The powder is discharged through the discharge grate to complete the grinding operation.

There is a circular cylinder, the two ends of the cylinder are equipped with the end cover with a hollow journal, the journal of the end cover is supported on the bearing, the motor rotates the ball mill through the gear installed on the cylinder, and the grinding medium (steel ball, steel rod or gravel, etc.) and the ore to be ground are installed in the cylinder, and its ** input is 25-45% of the effective volume of the cylinder. When the cylinder rotates around the horizontal axis according to the specified speed, the grinding medium and ore in the cylinder are lifted to a certain height by the cylinder liner under the action of centrifugal force and friction force, and then fall or throw freely from the cylinder wall, so that the ore is crushed by impact and grinding and stripping. The ore is continuously fed from the hollow journal at one end of the cylinder, and the ground product is continuously discharged through the hollow journal at the other end of the cylinder, and the movement of the ore in the cylinder is realized by the pressure continuously fed into the ore.

During wet grinding, the ore is carried away by the water flow. During dry grinding, the ore is carried away by the air flow that is drawn out of the cylinder.

The working principle of ceramic ball mill.

The motor drives the cylinder rotation through the deceleration device, and the crushed ore and steel ball in the cylinder are brought to a certain height by the liner by friction and centrifugal force when the cylinder rotates, and then it is thrown and dropped due to gravity, and the ore is gradually crushed under the impact and grinding. The crushed ore is discharged out of the barrel through the discharge section. After the discharged minerals are graded in the spiral classifier to the good product, the coarse sand is returned to the ball mill through the combined feeder for further grinding.

The feeder feeds the material continuously and evenly, the ore enters the ball mill continuously and evenly through the combined feeder, and the ground material is continuously discharged from the ceramic ball mill. The ceramic ball mill is a grinding equipment that can work continuously 24 hours a day.

The working principle of the lattice ball mill.

The lattice ball mill is composed of a cylinder part, a ore feeding section, a ore discharge section, a bearing part, a transmission part and a lubrication system. The cylinder is supported on the main bearing by means of an end cap. The cylinder and the end cover are lined with high manganese steel lining, and the lattice lining plate is also installed on the ore discharge side, and the small gear of different sizes is loaded into the cylinder according to the proportion, and the large gear on the cylinder is driven to make the ball mill rotate, and the ore is fed by the ore feeder, and enters the mill through the inner sleeve of the ore feeding journal.

The ground slurry is lifted to a level higher than the discharge port through the lattice liner through a fan chamber leading to the discharge port, so that the slurry is discharged from the mill. Due to the elongation and lifting effect of the fan chamber, the slurry stays in the mill for a short time, so the lattice ball mill is also called the forced discharge mill.

The working principle of the overflow ball mill.

The structure of the overflow ball mill is simpler than that of the lattice ball mill, except for some different structures at the discharge end, the others are roughly the same as the lattice ball mill, the main difference is that there is no lattice plate, and the inner surface of the hollow journal bushing at the discharge end is equipped with a spiral square and the rotation direction of the mill is opposite to the spiral blades, the purpose is to prevent the water balls or coarse ore blocks and the slurry from being discharged together, and the ore discharge of the overflow ball mill is by the slurry itself being higher than the lower edge of the hollow journal bushing and self-flowing overflow. Therefore, the liquid level of the slurry in the cylinder is higher than that of the lattice ball mill.

Compared with the traditional ball mill, the motor power of the ball mill can be reduced by 18-25%, the lubricating oil can be reduced by 70%, the cooling water can be saved by 90%, and the comprehensive energy saving can be more than 20%. Under normal circumstances, there is no need to replace the main bearing for ten years, which saves a lot of maintenance costs, labor and time; The main bearing lubrication is grease, which is convenient and clean, and eliminates heavy metal pollution.