This interest in rubber-based SAG grinding linings runs counter to the old belief that a SAG mill, using large-diameter grinding media, was too harsh an environment for rubber. Indeed, even though that remains true for most situations oversized balls kill rubber linings, said, one industry expert. The combination of metal’s resistance to abrasion with rubber’s resilience to sudden loading has opened new avenues for liner technology in some circumstances. The ball mill liner manufacturer is there with all the supports there.
Use of Rubber
Explaining this topic, the director of the mining division said that some important improvements have been made both to the quality of the available rubber and to the design of the lining segments. Headquartered in The successor company in the country, claims to have supplied rubber-based linings to more than 300 mills worldwide.
The theory suggested that rubber was good for coating secondary mills, but not for primary milling. Rubber linings are now used in SAG and AG mills up to 32 feet in diameter, with modifications such as steelwork. The big breakthrough here is that the use of rubber improves mill performance, although rubber may not be the universal panacea. Specifically, bar mills are less suitable for a rubber liner, especially in mill areas where the ends of the bars could strike the surface.
Discussing the different components that are now available, experts indicated that it is not necessarily a harder component that is better for mill liners. The main criteria are how the compound can handle the abrasiveness of the rock.
As all operators working in base metals and gold operations seek higher production, there will inevitably be greater demand for coatings. Larger mill liners wear out faster, typically after one year, while smaller mill liners can still be used after two to three years. Because of this, there is a greater demand for replacement liners for large mills, so companies have to have them in stock ahead of time.
The steel linings will continue to wear down, and they are heavy to move and store. With rubber liners, you don’t need as much inventory, so companies can plan better. In addition, the other great advantage is that rubber-lined mills make less noise than those using steel liners.
Practice Trends Affect Coating Requirements
In recent years, the trend toward smaller ore feed to SAG mills matched by a trend toward smaller balls in the SAG mill charge. High ball-to-rock ratios and low total mill load levels are now widely used. These practices can cause periodic loss of rock load and ball-in-casing damage. The long life of the liner in aggressive grinding environments requires careful mill operation to maintain rock load and avoid ball-over-liner damage, as well as robust mill liner design.
The large face angles that lift the hull, used to impact the “lift ball” on the heel of the load, can maximize the transfer of energy from the ball to the load and prevent harmful ball-in impacts. Wider liner gaps say 44 rows in a 33-foot mill can reduce ‘compression’ and increase lift speed, especially with smaller feed sizes, he added. The life of the external feed headliner can be extended by increasing the size of the plate bar that sits between the lifters.