Friday, 16 December 2011

A major milestone for stirred mills

Comminution has evolved rapidly this century, away from the traditional rod and ball mill circuits, towards circuits incorporating HPGR, and SAG and AG mills, and designing for the concentrators of 2020 is the main theme of April’s Comminution ‘12.

The need to grind ever finer, as ores have become more complex and of lower grade, has led to the successful adoption of stirred mills. The most successful of these has been the IsaMill, which has led the way in energy efficient fine grinding since its development in the early 1990s, delivering energy savings and improved metallurgical recoveries (see Wills and Napier-Munn, Chapter 7 for a full description).

Chris Rule and Lindsay Clarke
The world’s then largest ultrafine grinding mill, the 2.6 MW M10,000 IsaMill, was commissioned in 2003 at Anglo Platinum’s Western Limb Tailings Retreatment Plant in South Africa, and Xstrata Technology has recently celebrated the sale of the 100th IsaMill into the mineral processing industry worldwide (see MEI Online for full story). The mill was one of four large 3 MW, M10,000 IsaMillsTM installed in South Africa at projects operated by Anglo American Platinum, two of which are partnered with Xstrata Alloys and African Rainbow Minerals. This milestone was celebrated with a dinner attended by representatives from Netzsch, Anglo and Xstrata Tech. In the photo Lindsay Clarke – GM Mineral Processing, Xstrata Technology presents Chris Rule, Head of Concentrator Technology, Anglo American Platinum, with a gift to celebrate the milestone.

Chris will be presenting the first keynote lecture at Comminution ’12, 2020 - what will the typical PGM Concentrator flowsheet look like?, which will feature the use of IsaMills, and there are several other papers in the programme discussing their optimisation and also their use for coarse grinding applications. Noticeably the word ‘rod’ does not feature at all in the list of papers!

1 comment:

  1. For the past several decades, stirred mills have also played a key role in the production of high solids slurried ultrafine white pigments for application in the paper and architectural paint industries. The demand for steeper PSD also led to the development of specially designed centrifuges.


If you have difficulty posting a comment, please email the comment to and I will submit on your behalf