Material for Grinding Mill Rollers, Ring and Ploughs

it looks like the phosphate is the holder for the harder quartz/silicate component which abrades the steel. The bulk hardness of the phosphate is not the wear factor.

To defeat this, work with the mill manufacturer as they have seen all manner of rock mixtures and can suggest a superior alloy plate to be used as a partial refit(if you can) for trials. Based on the trial, you then decide what to buy.

Rock has a term called grindability, that they can test in the lab

http://www.google.ca/search?hl=en&safe=off&q=%22mill+construction%22+%2Bgrindability&btnG=Search&meta=

You may end up with carbide edged ploughs that cost 10 times as much but last 20 times as long, etc

We are manufacturers of pulverisers (but only for coal- thermal power stations)

The characteristics are entirely different- so can not be of much help to you.

We have as a post mentioned called grindability (or hardgrove index HGI for coals)

For us (again it may not be useful for you) -

The Manganese Steel Liners - Not much useful very low life - graduated from ages ago may be 30 Yrs or so.

Ni-Hard Type IV - still in use - much higher life.

Weld Overlaid Liners - Study N or Stoody-N or some name like that - USA made - Tried some 20 Yrs back - better than Ni hard, but again cost was too high and not commensurate with the life.

Then went to Hi-chrome

Now on carbide dispersed High Chrome and ceramics

(Sorry can not give the composition of quite a few, but these concepts are already commercially available but with various combinations)

Then again these are optimised for coal, and not for your very high hardness materials.

BTW: for these type of materials, the better option could have been Ball Mills rather than the Raymond's (in ceramic plants and also cement plants you will come across the ball mills only)

we have got checked this rock from the laboratory they provided following results for five samples of rock

hardness 7.2 to 7.8 Mohs

Bond Work Index (WI) 15.27 to 16.23

http://www.google.ca/search?hl=en&safe=off&q=grinding+%2B%22work+index%22&btnG=Search&meta=As

I think the softer rock acts as a holder for the harder silicate inclusions, which gives them resilience so they do not break up as easily and abrade the mill material.

I suspect the only cure is greater surface hardness to resist this wear. Again, mill makers have solutions...at a cost...to this problem. The balance between labor and replacing cheaper parts and the harder, longer lasting, premium components depends on labor and downtime costs.

When you say manganes steel, what is the analysis and heat treat/hardness?

milo

You may want to consider hardfacing the components. HVOF coatings like SUME SA, JETKOTE, TAFA would be candidates