Rod mill video:
Rod mill
Rod mill is a mill in which the grinding body loaded in the cylinder is a steel rod. Rod mills are generally of wet overflow type, which can be used as primary open-circuit grinding, and are widely used in primary grinding of artificial stone sand,
sand making machine, mineral processing plants, and power departments of chemical plants.
Rod mill in grinding process
In the grinding process, the grinding medium is in line contact with the ore, which has a certain selective grinding effect. The particle size of the product is relatively uniform, and there is less over-crushing. When used for rough grinding, the processing capacity of the rod mill is greater than that of the ball mill of the same specification.
MBS1830 rod mill in site 1
MBS1830 rod mill in site 2
Rod mill application
It is widely used in the first-level grinding of artificial stone sand, mineral processing plants, chemical plants and electric power departments.
Tips & precautions during use
1. Feed evenly
Uniform feeding is an important operation to ensure the highest output and stable quality (fineness) of the rod mill.
The fineness of the product becomes thicker, which generally means that the feeding amount is too large;
The fineness of the product becomes thinner, which means that the feeding amount is less
According to this principle, adjust the feeding amount in time.
2. Add steel rods in time
When will use a rod mill not a ball mill ?
1.When heavy separation or magnetic separation of tungsten tin ore and other rare metal ores, rod mills are often used to prevent excessive crushing;
2.In the second-stage grinding process, rod mills are generally used as the first-stage grinding equipment, which has larger production capacity and higher efficiency.
3.When processing softer or less hard ores, rod mills can be used to replace short-head cone crushers for fine crushing, which is not only simple in configuration, but also low in cost, and simplifies dust removal in the workshop.
Steel rod for rod mill 1
Steel rod for rod mill 2
Parameter of the Rod mill
The difference between rod mill with ball mill
1. Analysis of grinding media
The difference in grinding media is the main difference between the two
Rod mill: steel rods with a diameter of 50-100mm are used as grinding media, and the steel rods are in line contact
Ball mill: steel balls are used as grinding media, and the steel balls are in point contact
The steel balls of the ball mill are in point contact, and the steel rods of the rod mill are in line contact, so the working characteristics of the two are obviously different.
2. Application
Ball mill are more than fine grinding, rod mill are mostly used for rough
Rod mill: Mainly used in rough grinding. When the product size is 1-3mm, the processing capacity of the rod mill is greater than that of the ball mill of the same specification.
Ball mill: When used for fine grinding and the product size is less than 0.5mm, the grinding effect of the ball mill is greater than that of the rod mill of the same specification.
3. Performance analysis
Rod mill: The process characteristic of the rod mill is that the product is coarser, but the particle size is uniform, contains less coarse particles and sludge, and is lighter over smashing.
Ball mill: The performance characteristics of the ball mill are high production capacity, strong adaptability to materials, high degree of fineness of materials, and fine discharge granularity.
4.Analysis of medium filling rate
The medium filling rate refers to the percentage of the grinding medium in the volume of the mill. For different grinding methods, mill structures, operating conditions and media shapes, the media filling rate has a suitable range, too high or too low will affect the grinding effect.
Ball mill: filling rate is 40%-50%
Rod mill is 35%-45%
The packing rate of the self-mill is 25%-40%, and the packing rate of the gravel mill is about 43%.
Rod mill Working principle
Similar with ball mill working principle , When the cylinder rotates, the grinding medium (steel rod) installed in the cylinder is lifted to a certain height as the cylinder rotates under the action of friction and centrifugal force, and then throws down at a certain linear speed, so the cylinder is The materials inside are impacted, ground and squeezed to make them crushed.
Rod mill features
1. Energy saving
Older equipment saves more than 40% of power. The particle size of the product is more uniform, and there are fewer coarse particles and sludge. Compared with the particle size characteristics of the rod mill product and the ball mill product, the particle size characteristic curve of the rod mill in the open-circuit operation is almost the same as that of the ball mill in the closed-circuit operation.
2. The discharging granularity is more uniform and the output is higher
The use of high-quality controllable feeding and discharging rod mill technology, combined with the actual user’s grinding materials, is equipped with a suitable grinding body, which changes the surface contact of the traditional ball mill to line contact, so that the discharge particle size of the rod mill is more uniform and the output is higher. High, suitable for ores with different hardness (Mohs hardness 5.5~12).
3. Adjustable discharge fineness
The granularity of the discharging material can be changed by simple adjustment. The fineness control device is built-in, and the discharging device can be added with a screening device. The two checks ensure that neither over-grinding nor unqualified products are mixed into the finished product. The particle size characteristics of rod mill products are related to the ore crushed by rod mills. When the rod hits the ore, it first strikes the coarse particles, and then grinds the smaller ore particles, thereby reducing the risk of over-crushing. When the rod rotates and rises along the liner, the coarse particles are sandwiched in between, like a rod sieve, allowing fine particles to pass through the gap between the rods. This is also conducive to crushing the coarse particles and making the coarse particles concentrated in the grinding medium. The place to hit. Therefore, the rod mill product is more uniform, and the over-crushing is lighter.
