What are steel grinding balls?
Steel grinding balls are the grinding media and the core components of a ball mill. They can directly affect the grinding efficiency of the whole ore processing plant and the final product quality.
During the process, the ore is rubbing against itself. And the grinding media balls are rubbing against the ore to realize the material size reduction.
Steel grinding balls specifications and quantity
The size of grinding steel ball can be designed according to customer requirements. Generally, the diameter of a steel ball is between 20mm and 125mm.
Among them, small steel balls are 40mm or 60mm, medium balls are 80mm, and large steel balls are 100mm or 120mm. The diameter of super large balls is 130mm to 150mm.
Theoretically, when the filling amount of steel grinding balls in the cylinder of the ball mill is 40%, the ball mill can obtain an ideal output.
However, in actual production, the filling rate of steel grinding balls in the cylinder of the ball mill is around 35%, that is to keep the volume of balls in the cylinder slightly lower than the horizontal centerline of the ball mill.
What are steel grinding balls made of?
Each ball is a solid steel grinding ball from surface to center. They all have a perfect hardness for ball mill grinding.
Steel grinding balls made of high manganese steel
Steel grinding balls made of high manganese steel have good toughness, good manufacturability and low price. Under the action of great impact, the surface of high manganese steel will become harden quickly.
The steel grinding balls' hardening index is 5 to 7 times higher than other materials, and the wear resistance is greatly improved.
Steel grinding balls made of low carbon alloy
Steel grinding balls made of low carbon alloy has good toughness and low price. Under the same working conditions, the service life of these mild steel balls is more than 1 times higher than that of low chrome cast steel grinding balls.
Steel grinding balls made of high carbon and high manganese alloy
Steel grinding balls made of high carbon and high manganese alloy mainly contain chromium, molybdenum and other kinds of elements. They have high hardness and good toughness. Under the same working conditions, the carbon ball' service life is more than 1 times higher than that of high manganese steel balls.
The quality of steel grinding balls has a great relationship with the consumption of balls. Using high-quality and wear-resistant steel grinding balls can reduce ball consumption and improve grinding efficiency.
How are steel grinding balls produced?
Steel grinding ball production process:
- Rough: Steel grinding balls use bearing scrap steel as raw material, with a large amount of copper, molybdenum, nickel and other precious metal elements added to make the structure more compact. After checking, the round steel bar is cut into steel ball billets in fixed lengths;
- Heating: Steel ball billets are heated to an appropriate temperature in a continuous heating furnace;
- Forging (rolling) into balls: The red-hot billets are sent to steel ball mills, then rotates forward between two rolls with spiral-shaped holes to be continuously rolled into balls. Each steel ball mill can roll 60 to 360 balls per minute;
- Heat treatment: By adopting the most advanced and reasonable oil quenching production line, the rolled red-hot steel balls will immediately undergo quenching-tempering heat treatment;
- Final check and pack: After the final check, steel grinding balls are sent to the warehouse for packing. Then the products are sold to customers.
Why FTM steel grinding balls?
FTM steel grinding balls have the following outstanding advantages:
- High hardness: The surface hardness of FTM steel grinding balls can reach 55 to 65HRC. The volume hardness can reach 50-62HRC, and the hardness distribution inside and outside the balls is even;
- Round steel balls: FTM balls are round steel balls with precise dimensions;
- High impact resistance: Each of FTM ball is a solid steel ball with good mechanical properties. All the indicators have reached the leading standards of mining machinery;
- Low crushing ratio: The resistance to flaking and crushing is more than 10 times that of the general steel forged balls. The number of impacts of falling balls can reach more than 100,000 times. And the actual crushing rate is less than 1%, which is close to no crushing;
- High efficiency: FTM is a steel ball manufacturer who can help you improve the efficiency of the ball mill and achieve higher productivity.
How to select and add steel grinding balls?
Steel grinding ball proportioning can greatly affect the output and quality of the ball mill. Only by ensuring a certain proportion of various balls, can they be adapted to the particle size of ground material, and achieve a good grinding effect.
Basic principles of steel grinding balls proportioning
1. Processing of ore with large hardness and coarse particle size requires greater impact force and needs to be loaded with steel grinding balls of larger size. The harder the material, the larger the ball diameter;
2. If the diameter of the ball mill is large, the impact force will be large. Then the diameter of steel grinding balls should be small;
3. If a double-chamber partition is used, the ball diameter should be smaller than that of a single-layer partition plate with the same discharge section;
4. Generally, follow the principle of "less at two ends and more in the middle", that is, four-level ball distribution, with fewer large and small steel balls, and more balls in the middle.
How to add steel grinding balls to a ball mill?
1. When you use the ball mill for the first time
In the first time, the steel grinding balls must be added at 80% of the maximum ball loading capacity of the ball mill. And three sizes of balls, namely, large, medium and small, are required for proportioning.
Different ball mill models have different ball loading capacities. For example, the ball loading capacity of Ф1500x3000 ball mill is 9.5-10 tons. For the first time adding balls, large steel balls (120mm and 100mm) account for 30%-40%, medium steel balls (80mm) are 30%-40%, and small steel balls (60mm and 40mm) are 30%.
After normal continuous operation for two or three days, check the meshing of the large and small gears. If everything is normal, add the remaining 20% steel grinding balls for the second time.
2. Under normal circumstances
Under normal circumstances, it is not necessary to add small steel grinding balls. When the ball mill is operating normally, friction will occur between the ball and ball, the ball and the ore, and the ball and the ball mill liner. The friction will become larger and then grind the large balls and medium balls into small ones.
However, small steel grinding balls would be added if the particle size is not implemented with a mineral monomer dissociation, and mill fineness does not reach the sorting requirements (especially flotation sorting requirements).
In addition, the steel grinding balls of the ball mill are constantly worn out during operation. In order to maintain the stable operation of the ball mill, reasonable ball replenishment must be carried out to offset and compensate for the wear and tear.
Parameter
The sizes of steel grinding balls can be designed according to customer requirements. Generally, the diameter of steel balls for sale is between 20mm and 125mm. Among them, small steel balls are 40mm or 60mm, medium balls are 80mm, and large steel balls are 100mm or 120mm. The diameter of super large balls is 130mm to 150mm.
The sizes of steel grinding balls can be designed according to customer requirements. Generally, the diameter of steel balls for sale is between 20mm and 125mm. Among them, small steel balls are 40mm or 60mm, medium balls are 80mm, and large steel balls are 100mm or 120mm. The diameter of super large balls is 130mm to 150mm.
