Improving mill lining systems

Vulco rubber is well known throughout the mining industry for its exceptional wear life and reliability in mill lining systems. These abrasion- and impact-resistant rubber compounds have been developed with advanced technologies by the Weir Minerals’ team of engineers and material scientists who are continually refining Vulco rubber products to keep them at the forefront of mill lining systems technology.

Having identified a need for higher-wearing rubbers for mill lining systems, the material science experts began developing a premium-grade rubber compound with superior wear life and performance in mill lining applications. The result was the Vulco R67 rubber – an optimum material that is manufactured with new compounds and innovative methods of processing to deliver outstanding wear life and longer uptime.

Extensive field research, compound testing and site trials were conducted to ensure that it was able to withstand severe abrasion in typical mill system applications. It has been the most wear-resistant rubber compound that Weir Minerals has ever developed for mill lining applications. The R67 compound boasts a high hardness, elongation, tensile and tear strength, and is suitable for lifter bars, head/shell plates and grates. When it’s used in conjunction with metal cap mill liners, the result is a versatile, economical and efficient product that weighs up to 50% less than steel alone. The added benefit is a lighter product that’s faster, easier and safer to install.

Since its launch in 2018, many mining operators have implemented the R67 compound into their mill lining systems. Some have reported as much as 20-40% improvement in wear life, which is resulting in fewer mill lining replacements and longer mill campaigns. This reduction in shutdowns has a dual benefit of increased cost savings and improved plant availability.

What are the benefits for the mill operators?

With a liner that can run significantly longer, operators have experienced a wide range of benefits including: improved wear life, a measurable reduction in mill downtime and increased uptime and processing. Other benefits include easier and safer installations and reduced maintenance costs.

In addition to this, the operators benefit from having an experienced and dedicated team from Weir Minerals who custom-engineer the liners to suit each mill’s unique requirements for optimal wear life.

Weir Minerals believes that the R67 elastomer compound is changing the way mills operate. Extensive global trials and commercial installations in the market have resulted in a number of successful outcomes across a variety of different grinding applications. From mines in the USA to Chile, the R67 has proven its outstanding performance.

As an example, a high-grade nickel and copper mining project in the USA had a problem where the liners in one ball mill were wearing out too quickly, leading to continued downtime and reduced processing. The team was looking for a product superior to the elastomer that it was using. Initially there was reluctance from the mine, as the team had loyalty to its original mill supplier, however after Weir Minerals conducted a series of trajectory simulations and discreet modelling - to optimise the design and deliver the best process performance for the mill, the team agreed to trial the R67 liners. At the end of the trial the R67 showed 30-40% better performance than the previous liners and the customer installed a full set of R67 liners in its mill.

Another trial in the USA took place in an iron ore mine with several dozen ball mills in operation. Here, Vulco R67 liners delivered a 17% increase in life compared to the failed shell plates from the mine’s original mill lining system supplier. The company was extremely impressed with the results and installed a complete shell liner in their ball mill.

In Chile, a copper mine operator was keen to trial the R67 compound to see if it could improve the wear time of a competitor rubber liner. After a three-month trial, all liners were physically measured showing that the Vulco R67 liners fully worn wear life projected from the actual wear would be 80% longer compared to the competitor liners.

Another copper processing plant in Chile trialled R67 composite liners in its SAG mill against two other compounds that are commonly used in the industry. After 12 months, there was a 48% and 62% wear life improvement on the other liners – proving that the R67 composite liners could withstand the highly abrasive environment.