Ball Mill

ball-mill
Working principle
Ball is from the cylinder, out of the hollow shaft and grinding head and other parts of the horizontal composition of the cylinder for the long cylinder, cylinder with grinding, cylinder is of steel manufacturing, there is a steel cylinder liner and fixed grinding Usually made of steel spheres, according to a certain percentage of different diameters and loading cylinder, grinding steel segment can also be used.
Be selected according to the particle size of milled material, material from the mill feed end of the hollow shaft into the cylinder body, when the ball cylinder rotation when grinding body due to inertia and centrifugal force, the role of friction, it is attached to the cylinder liner He was taken away by the barrel, when was brought to a certain height, because of its own gravity has been thrown down, falling like a projectile, like grinding the material to the cylinder body crushed.
Material from the feed device evenly into the mill first warehouse into the compound by the air shaft spiral, the warehouse there are ladder liner or corrugated liner, built with a variety of balls, rotating cylinder produces centrifugal force to the ball a certain after the height of the fall, have severe impact on the material and abrasive. Material in the first position to reach coarse grinding, through the single-compartment plate into the second warehouse, the warehouse lined with flat lining, steel ball inside, the material further grinding. Powder is discharged through the discharge grate plate to complete the grinding operation.
During the rotation of the cylinder, the grinding media have dropped the phenomenon, in the process of falling to the material to abrasive action, in order to effectively use abrasive effect on the material size larger general purpose Ground twenty when the mill body cylinder plate with a compartment divided into Sec, becomes two-position, the material into the first position when the ball was crushed, the material into the second position when the steel section of the material for grinding, grinding the material passing from the discharge end of the hollow shaft discharge of feed materials for small particles when finely ground, such as sand II slag, coarse fly ash, mill shell not to set partitions, a single-chamber tube mill, grinding can also be of steel segments.
Raw materials through the hollow journal to be milled into the hollow cylinder, the cylinder built with various diameters grinding media (steel balls, steel bars or gravel, etc.). When the drum about a horizontal axis at a constant speed of rotation when mounted in the barrel media and materials under the effect of centrifugal force and friction, as the cylinder reaches a certain height, when the centrifugal force greater than gravity itself, it is outside the cylinder the inner wall of the projectile falling or rolling down, due to the impact force to crush ore. While during the rotation of the mill, grinding media sliding movement between each other for raw materials also produce abrasive. After grinding the material discharged through the hollow journal.
Mechanical structure
Ball from the feeding part, discharging Department, Rotary Department, the Ministry of transmission (reducer, small transmission gear, motors, electrical control) and other major components. Cast steel hollow shaft, lined with removable, rotary gear hobbing by casting process, the body inlaid cylinder liner wear, has good abrasion resistance. The machine running smoothly, work reliably.
Host mill comprises a barrel, the body inlaid cylinder liner wear-resistant materials, have carrier and maintain its rotating cylinder bearings, but also a driving portion, such as motors, and transmission gears, pulleys, belt and so on.
Parts on called blade, generally not a major component in the feed end member inlet has spiral can be called the inner helical blade in the discharge end of the member discharge port has internal spiral it may well be within the spiral vane.
Also in the discharge end of the secondary device if a screw conveyor, the device will be called in the spiral blade parts, but strictly speaking, it is not already part of the mill.
According to materials and methods of discharge, optional dry ball mill and wet lattice-type ball mill. Energy ball mill, the use of self-aligning double row spherical roller bearings, small running resistance, energy-saving effect is remarkable. Cylinder part of the original cylinder discharge end of a period of increased cone cylinder, both to increase the effective volume of the mill, and make more rational allocation of medium barrel. The products are widely used in non-ferrous metals, ferrous metals, non-metallic mineral processing field and chemical, building materials industry for the grinding of materials to use.
Improve efficiency
(1) to increase the effective volume
Increase the effective volume of the mill can be an increase mill productivity, lining thickness, weight, increased power consumption, but also reduces the effective volume of the cylinder, reducing the productivity of the mill. Such as the use of magnetic liner, it can increase the effective volume of the cylinder, while the weight is relatively reduced, power consumption is reduced. However, use a thin magnetic lining also has some drawbacks, due to the small thickness, resisting ability as good as a Cr-Mn Mo alloy steel liner active, prone to cracking problems. For example, some manufacturers use problem liner trench ring liner, increased ball contact surface mining, milling strengthen the role and enhance the capacity of the ore has reduced energy consumption, are widely used.
(2) an increase in fill rate and transfer rate
Ball mill processing capacity with the ball filling rate increases, increase the filling rate increases ball mill crushed ore and ore chance autogenous grinding effect. Ball filling rate at a maximum load of 45% ball mill, with the filling rate of increase in its load dropped significantly more than 45%. This is mainly because the filling rate increases, throw the ball from point is raised, the ball hit the joint effect of falling red dot near the center of rotation to accelerate and exceed its combined torque is greatly reduced and becomes negative to O, steel balls (including mine) hit down the impact of closing large torque required by the load becomes 0, until becomes driving force behind the rotating cylinder (ie, beyond the center point of force, resultant moment is negative).
(3) changing the shape of the grinding media
Medium oval ball can be used instead of the active media sphere, ellipsoid compared with the sphere, its advantages are as follows:
Compared with the sphere spheroid, can mill crushing and grinding capacity has been greatly improved, and the device also has a corresponding reduction in the loss.
Technical Parameter:
Model Rotary Speed(r/min) Weight of Inner Ball (t) Feeding Size (mm) Output Size (mm) Capacity (t/h) Motor Power(kw) Weight (t)
900×1800 38 1.5 ≤20 0.075-0.89 0.65-2 18.5 3.6
900×3000 38 2.7 ≤20 0.075-0.89 1.1-3.5 22 4.6
1200×2400 32 3.8 ≤25 0.075-0.6 1.5-4.8 45 12.5
1200×3000 32 5 ≤25 0.075-0.4 1.6-5 45 12.8
1200×4500 32 7 ≤25 0.075-0.4 1.6-5.8 55 13.8
1500×3000 27 8 ≤25 0.075-0.4 2-5 90 17
1500×4500 27 14 ≤25 0.075-0.4 3-6 110 21
1500×5700 27 15 ≤25 0.075-0.4 3.5-6 132 24.7
1830×3000 24 11 ≤25 0.075-0.4 4-10 180 28
1830×6400 24 23 ≤25 0.075-0.4 6.5-15 210 34
1830×7000 24 25 ≤25 0.075-0.4 7.5-17 245 36
2200×5500 21 30 ≤25 0.075-0.4 10-22 370 48.5
2200×6500 22 30 ≤25 0.075-0.4 14-26 280 52.8
2200×7500 22 33 ≤25 0.075-0.4 16-29 380 56
2200×9500 21 38 ≤25 0.074-0.4 18-35 475 62

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