LMBRM Ball and Rod Mill
The Ball and Rod Mill type LMBRM is a process and laboratory machine, which is suitable for milling and homogenizing soft, fibrous, hard and brittle materials in dry and wet phase.
The LMBRM is suitable for normal and Bond grinding, depending on the (size) drum. Because the machine has a changeable opening, different sizes of drums can be fitted in the machine. With a manual and automatic operating system it is suitable for many applications. With changeable time, rotation and speed settings the LMBRM can be fully set to your requirements.
The drum lifting device insures that the lifting and positioning is easy.
The device has two guide-openings at the bottom receiving the wheels to ensure that the lifting device is positioned correctly releasing the drum in the machine.
The drum lifting device comes with a foot paddle and a lowering knob to reducing the physical load to a minimum.
Features and Benefits
- Variable speed setting
- Modular drum with an volume from 1 to 42 litre
- Ergonomic sample separation set consisting of outlet funnel and screens with handle
- Removable sample collector
- Solid acoustic noise reduction housing with safety detection to stop the motor when hood is opened
- Can be produced for bond norm applications
- Touch screen control panel
- Emergency stop button
- flexibility in milling application due to switching between rod and ball drums
Technical Specifications
| Ball and rod mill | Bond ball mill | Bond rod mill | |
| Applications | separation of different materials, particularly minerals, by agitating a pulverized mixture of solids in liquids |
measurement of the grindability of materials | measurement of the grindability of materials |
| Working principle | Grinding | Grinding | Grinding |
| Feed size | < 25 mm | 3,35mm | 12,50mm |
| Feed quantity | depending on drum size | 15kg | 20kg |
| End fineness | < 20 µm* | 100 micron (µm) | 2100 micron (µm) |
| End fineness adjustment | By variable speed setting and ball / rod charge | - | - |
| Speed setting | 10-70 rpm | 70 rpm requirement | 46 rpm requirement |
| Setting adjustment method | digital control panel | digital control panel | digital control panel |
| Drum diameter | 300mm | 304,8mm / 12 inch | 304,8mm / 12 inch |
| Drum length | 300mm - 600mm | 304,8mm / 12 inch | 609.6mm / 24 inch |
| Drum volume | 1,6,12, 21 or 42 litre | 21 litre | 21 litre |
| Drum specification | standard | Rounded corners, smooth wall, no lifters | Wave structure |
| Consumeable material | stainless steel or hardened steel grinding balls | stainless steel or hardened steel grinding balls | stainless steel or hardened steel grinding balls |
| Consumeable sizes | grinding balls: 0.5mm - 80mm |
43 x 1.45” balls 67 x 1.17” balls 10 x 1” balls 71 X 0.75” balls 94 x 0.61” balls |
2 x 1.75 inch diameter x 21 inch length rod 6 x 1.25 inch diameter x 21 inch length rod |
| Sieve grid sizes | custom, depending on grinding ball sizes used | - | - |
| Collector size | 20 litre | 20 litre | 20 litre |
| Electrical requirements | 2,2 kW | 2,2 kW | 2,2 kW |
| Power supply | 400V ± 10% ± 50/60Hz | 400V ± 10% ± 50/60Hz | 400V ± 10% ± 50/60Hz |
| Power connection | 3 phase | 3 phase | 3 phase |
| Dust extraction point | 1 | 1 | 1 |
| Standard | CE | CE | CE |
| Protection code | IP40 | IP40 | IP40 |
| Weight | 475kg | 475kg | 475kg |
| Dimensions (width x length x height) | 735 x 1415 x 1360 mm (closed) 1127 x 2368 x 1360 (open) |
735 x 1415 x 1360 mm (closed) 1127 x 2368 x 1360 (open) |
735 x 1415 x 1360 mm (closed) 1127 x 2368 x 1360 (open) |
Ball and Rod Mill working principle
The LMBRM Ball and Rod mill can utilize both ball and rod drums. This mill is versatile and can be adapted to either rod milling or ball milling, depending on the application.
The Ball and Rod mill consists of a large cylindrical shell, made from stainless steel, which rotates around its horizontal axis.
The shell is designed to withstand the forces and wear associated with milling both using rods and balls.
The rod mill drums has a larger length-to-diameter ratio (1.5 to 3.0), while ball mill drums have a shorter ratio (1.0 to 1.5).
A combination mill is designed with a flexible ratio, allowing it to accommodate both modes of operation.
The mill is mounted on bearings and driven by a motor. This ensures the rotation of the mill at the required speeds for grinding.
In ball milling, a ball drum filled with steel or ceramic balls is used to perform impact and attrition grinding.
The material to be ground is introduced into the drum, and as the drum rotates, the balls tumble and crush the material.
For rod milling, a drum filled with steel rods is used.
Rods create a more uniform grinding process through cascading and rolling action, and they are better suited for coarse grinding and feed materials with large particle sizes.
The mill is designed to allow for easy switching between the two drums for using balls or rods
A mill capable of using both ball and rod drums is a versatile grinding machine, designed to handle different types of materials and provide flexibility in particle size reduction.
This dual-purpose design offers adaptability for a wide range of industrial applications, including mining, mineral processing, and material preparation, allowing operations to efficiently switch between coarse and fine grinding methods.
Bond applications
The LAARMANN® ball / rod mill is designed to meet the industrial requirements to grind coal, cement and a wide variety of ores related to the Bond ball mill and Bond rod mill work index
This index is used to calculate the power draw requirements of a rod mill. Furthermore it allows more precise calculation of the required comminution energy.
The RWI index is used for a secondary crusher product size in the range 25mm down to 2,1mm and BWI index is used from 2,1mm down to 100?m which is the usual product size.
The ball / rod mill consists of a gear motor mounted on a high precision solid steel underframe complete with outlet funnel and a set of separation screens plus sample collector.
The optimum number of balls for the bond ball mill is 285 . However as the balls wear their size varies. Accordingly the total number of balls must be adjusted to give a final mass of 20,125 grams. Do not
remove all balls of one size and try to maintain the correct proportion of balls by size. Make fine adjustments by adding or removing small balls.
Control Panel
rod mills are often equipped with sophisticated control systems that monitor and adjust various parameters, such as mill speed, time settings, and assistance when filling or emptying the drum. The mill must have an adjustable speed control system to adapt to different grinding media. Rod mills typically operate at lower speeds than ball mills, so the motor and drive system must be flexible enough to accommodate both modes. These options help optimize the milling process for efficient and consistent results.
Grinding Media
Ball mill drum uses spherical grinding media (balls) made of steel, ceramic, or other materials. Ideal for fine grinding, often producing very fine particle sizes.
Operates at a higher rotation speed compared to rod mills.
The Rod Mill drum uses long, cylindrical steel rods as grinding media. More efficient for coarse grinding and materials with larger feed sizes.
Rods operate in a tumbling motion, creating parallel grinding paths for more uniform size reduction.
LM-BRM Ball and Rod Mill FAQ (Frequently Asked Questions)
- Mining and mineral processing
- Metallurgical labs and refineries
- Material science and ceramic labs
- Geological and quality control labs
Applications
- Rod mills are widely used in mineral processing plants to grind ore prior to other processing steps, such as flotation or leaching.
- They are particularly effective for grinding brittle materials or materials that are not overly hard.
- Used in coal preparation plants to grind coal into a fine powder for use in power generation or for further processing.
- Utilized in the grinding of raw materials and clinker in the cement production process.
- Rod mills can be used to produce fine aggregates, such as sand, by grinding raw materials like granite or limestone.
- Suitable for fine grinding in applications such as mineral processing, cement manufacturing, and fine powder production.
- Commonly used when finer particle sizes are required.
- Best for coarse grinding of ores and materials, often used in the initial stage of grinding circuits in mining.
- Rod mills are preferable when the feed is larger and a relatively coarse product is desired.
Cement, cement clinker, concrete, coal, coke, minerals, ores, slags, soil samples, sludges, glass, ceramics, corundum, pharmaceuticals, chemicals, food, animal food, creams and emulsions, paint
Visit our Applications page for our database of specific applications