Ball mills and rod mills are both excellent mining machines for grinding ores into fine powders and particles. The calling name of ball mill and rod mill is from the different grinding medium. The ball mill’s grinding medium is steel balls, which is a kind of high-strength wear-resisting material.
The grinding medium of rod mill is steel rods. However there are some advantages to using rod mills rather than ball mills for larger mining projects including greater efficiency, better grinding performance and lower energy costs. Though ball mills are used more often rod mills can be the better option for specific mining ores and larger site projects.
How to choose the ball mill and rod mill is a confused question for many customers, let’s come to do a detailed explanation and analysis below:
1. Rod mill is line contac, ball mill is point contact;
2. The product particle size of rod mill is more uniform than that of ball mill, the product granularity of ball mill is smaller and more fine;
3. The particle size distribution accumulation of ball mill is more efficient than rod mill;
4. The wear rate of rod is lower than the ball’s, for ball mill in routine attention it needs add a certain amount balls often, but for rod mill it needs only check and change the rods in a period of time;
5. Ball mill’s power consumption is slightly more than rod mill’s. In a ball mill the actual balls in the machine need to cascade in order for the grinding to be accomplished. Because of this more energy is needed to power up a ball mill as opposed to a rod mill. Rod mills can be operated at lower peripheral speeds resulting in reduced energy costs.
Though this difference in power can vary depending on the type of ore you are grinding, the consensus is that a rod mill requires less speed to perform the same function as a ball mill.
Another key factor in choosing a rod mill over a ball mill is void space. You ideally want as little open space as possible so you have more grinding contact between the rods and the ore. Ball mill needs more open space so the balls inside can cascade and grind but this space lessens the contact between metal and ore per surface area. Again, depending on the site project media rod mills won’t necessarily always be the better option but if you are concerned about void space in your grinding process a rod mill may be the right choice. If you are working on a mining site that is excavating large pieces of rock, coal, copper or other mining media then a rod mill may be a better fit than a ball mill.
Steel rods are more suited to breaking up larger pieces of ore due to the heavier weight of the rods. As well, heavier ore produces more energy per collision which can be better optimized by steel rods rather than balls. If you need to grind mining media down to fine particles then a ball mill is recommended. But if the material is large, consider a rod mill for the heavy duty grinding.