Hi Sharad,

This is pretty standard for Run of Mine operations in a copper mine. But please explain what you mean by "Bridge Reclaimer". It sounds like you are taking ore from the face of your ore body, open cut, through some form of a grizzly to cut oversize and want to take it off site for processing at some other plant location. Is that correct?

Do you have an intermediate stockpile that you have to reclaim?

Please advise - Sgt John.Rz

www.latviantourists.com.au ■

Your luffing stacker will develop bed layers of mainly 300mm lumps which will improve drainage. So long as your harrow can disturb enough pile face to maintain your reclaim requirements then you should not have many problems.

An A-frame portal reclaimer, for just one alternative example, would impose storm run off deluges on your take out conveyor. Your 30% moisture content is surely exhibiting free water and any slopes towards the outbye conveyor should be minimised. In this regard I would drain severely along the side of the pile away from the outbye belt.

In reclaiming; I would expect your material to form a noticable wall, about 600mm high, against the bucket envelope. Harrowed ore will overshoot this wall quite normally, continually, and land at the far side/middle of the bucket path (from the pile face). As the wall periodically collapses, from undercutting, the larger rocks become concentrated nearer the pile face side of the chaintrack. So when it all gets to the belt the larger lumps hit first; if you are driving one way. If you drive the belt the other way you get fines first, which is what we all want. If you can reclaim (and first of all stack) on both sides of the reclaimer (a twin harrow job - worth the extra money) then the imbalance is irrelevant.

Stickiness is something you will have to live with. It won't be pretty but the malicious accretion growth will be limited by the machine operating dynamics. i.e. it will shake most of the crap off.

I just love repeating 'malicious accretion' ever since I read it in a yesteryear spec from WS Atkins & Partners. Funny how we paint things battleship grey and then worry about their appearance during operation.

Tip; make sure the chaintrack: chain, guides, buckets & rollers are strong enough for the motor stall condition. That way you won't be worried about excessive 'out of spec' oversize.

As Teus would say...Success. ■

Hi Sharad,

You say that your Nickel ore material has lump size as 300 mm max. and 80% below 120 mm and 40% below 50 mm.Moisture content is 30% and material is very sticky and abrasive.

You are handling mud and rough ore at 300 mm. That is abrasive. the sticky part is smaller than 1 mm. the 30% moisture is a transitory condition, carried by the fines. The sticky part [slimes] will ultimately have to go to the tailings dam.

1 - the ore type is similar to iron, copper, and the soft rocks of mineral sands. The most common way to provide some surge or standby capacity is to build a cone stockpile which can be reclaimed through a tunnel, say stockpile 20 m high, 40 m diameter [this also helps to drain the water to reduce water content]. Occasionally a cross feed is provided to form 2 or 3 cones close to gether, fed by the same conveyor, and reclaimed by 2 or 3 feeders.

2 - The moistsure can be driven off through some form of vibrating bed before it reaches the stockpile. This could drop the moisutre to 12% or so. Fines will still dribble at shafts and odd spots of 'malicious accretion' .

3 - the stock piles are usually reclaimed through a tunnel into a truck loading or train loading facility. During Shutdowns in the Mine a front end loader can be used to reclaim ore to the underground feeders in the relaim tunnel.

4 - Because of the fines this can be an operation subject to fugitive dust (another form of 'malicious accretion' ). At Mt Keith the decision on how to handle the dust problem was held until we saw how the nickel stockpile feeding the SAG Mills behaved [I believe that water spray dust suppression was finally selected).

5 - An other alternative [used with iron ore] is to place primary and even secondary crushers at the mine face.

6 - With diamond mud and coal we simply wash the ore to get rid of much of the mud/slimes.

Regards - Sgt John.Rz ■

Sharad,

Can you please elaborate on your import scenario? If you are hauling that sort of material out of a ship or barge I would expect more concern along the harbour edge. ■