Chrome balls last longer and do not break easily as compared to forged balls. Expensive in terms of the value per ton of Steel-balls, but very economical in terms of the consumption rate.

In which type of the mill are you using them?

We use both ball mill and SAG mill.

I think in ball mills you can use steel balls which are very resistant to wear rates, but in SAG mills its tricky as the accumulation of small steel balls due to low wear rate in the mill will affect so much your power draw, meaning that your power draw will be high whilst grinding efficiency is reduced as in SAG mills you need larger steel balls, this will cause a reduction in throughput. So you need smaller steel balls to disappear faster in the mill and replenish with larger one so as to keep impacts at maximum, but you also need a reasonable wear rate of the larger ones so as to manage costs.

So are suggesting that we go for Hi chrome in the ball mills instead of the SAG mill too?

Yes you can use them in ball mills.

http://www.magotteaux.com/products-services/grinding-media/ would be one to get in contact with as someone else mentioned. They have justified the difference at lots of sites and released papers on the topic at a number of conferences. The best way to work out if it is likely to be helpful for your site is to discuss with a supplier and work out how to conduct either lab and/or plant trials depending on your situation.

We tested in our ball mill, there was meant to be a step change in recovery based on slurry potentials and DO, however, from the data analysis, there was nothing that could be confirmed. This was somewhat due to our method of campaigning different ores on a short term basis (2 week to 2 month campaigns), so the data analysis was reasonably difficult - however, a step change would have stood out like the proverbial. From a wear perspective, high chrome were better, however, the cost difference in high chrome to forged steel essentially eroded that benefit. In all we steered away from it.

High Chrome has been trialled in a few plants, we tested at the Copper Concentrator at Mt Isa in the 90s. Generally the change has to be justified on a combination of reduced media consumption rate, and improvements in flotation chemistry (Eh) that leads to better concentrate grade and recovery. It generally takes many weeks of a plant trial to determine if it is worth it. Agree that Chris Greet and his team at Magotteaux are worth talking to, he's knowledgeable.

In SAG and BM,it is better to choose forged balls in wet working conditions.