electron1539
50 posts
TimePosted 03/10/2009 12:21:15

quarry and mix optimization

Dear experts,

 if we have a quarry situation of high variation of lime stone quality  without presence of any aid like  surpac , QSO .... etc of software which facilitate quarry optimization 

 what is the best practices for material selection ( limestone )   ,   suitable and representative sampling method from blasting to have representative chemical analysis for it   and   mixing which all lead to reduce the mixing variation and improve mix uniformity

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Ted Krapkat
536 posts
TimePosted 06/10/2009 05:58:58

Re: quarry and mix optimization

Hello Electron1539,

Do you have a cross-belt analyser after your crusher? If not, how do you currently test the crushed limestone from the quarry when preparing stockpiles. And what type of stockpile blending do you use.

 Regards,

Ted.

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electron1539
50 posts
TimePosted 06/10/2009 09:51:13

Re: quarry and mix optimization

i forgot to tell that there is no cross belt analyzer - we test the lime stone by analyze the pore holes of blasting drilling - we test the staked lime stone by graped sample from the belt of the staker - and the storage is a prehomo longitudinal storage

 

this is to complete the situation image

 

 

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Ted Krapkat
536 posts
TimePosted 07/10/2009 02:50:49

Re: quarry and mix optimization

Okay, thanks Electron1539,

I was laboratory manager in a quarry similar to your situation some years ago. At the time we tested our limestone by acid titration from grab samples taken from the stacker belt at 20 minute intervals and analysed a composite of these samples hourly.

This result was immediately communicated to the crusher operator who directed the mine equipment, by two-way radio, to move to the appropriate grade of blasted limestone available in the quarry at any given time.

At the end of the day the daily composite was analysed by XRF and together with the tonnes of limestone crushed, this data was entered into a simple computer program which calculated the weighted average of the stockpile since it was started.

Using these results the titration (%CaCO3) aim for the next days production could be calculated so that at the end of crushing the stockpile it was on target. We controlled the CaCO3 content of the stockpiles to 90 +/- 1% in this way.

This method however, requires close cooperation between the lab tester/chemist, the crusher operator and the quarry team leader in order to react quickly enough to achieve the laboratory's daily targets.

Today, with more rapid XRF testing you probably don't need the simple titration test, but the methodology is the same.

An XRF is also absolutely necessary to rapidly analyse your drill-chip samples from the quarry blast holes. Again, a simple weighted average of the analysed holes will give you the expected quality of the whole, or selected parts, of the blast pile.

Of course it is always better and easier to use a cross-belt analyser with Quarry Master of similar program, but they are expensive.

I controlled the quality of a quarry for 15 years using the manual method I mentioned above, with very few quality issues and an acceptable rawmix variability.

I hope that information is useful to you,

(P.S. For your info, Thermo Fisher (Gamma-metrics) are currently developing a bore-hole analyser (BHX) which fits on a drilling rig and analyses the drill chips by Laser Induced Plasma Spectroscopy in real time, as the blast holes are being drilled. The instrument is currently in the trial partnership stage and it shouldn't be long before this technology is available on the market. I have no information on the expected cost though.).

Ted.

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