Greetings,

lignite is still surfaced mined in both texas and germany as far as I know. The shallow lignite is still mined with a BWE but my information is a little dated.

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You could start by contacting the folks at "engineering and mining journal" also contacting the manufacturer of your BWE if they are still a going concern.

There is a lot of water dredging data available in lot of places and it is almost identical as far as the method goes.

Surface mining using the BWE method is common place, you could ask the other operators in your part of the world.

As far as raw information/papers/studies and contact the engineering schools in germany, in the united states you could contact the columbia school of mines, the Colorado School of mines,The university of Missouri, The United States Army Corp of Engineers, and many mining publications in general.

Another good source would be the Bituminous coal Operators Association in the United States.

Using a BWE is no different than water dredge as it moves from left to right then drops a foot or two and repeats from right to left.

The limiting factor is the bucket wheels revolutions per minute simply because it will dig and cut and continually fill the buckets to their rated capacity if forced fast enough but the wear and tear is the problem as it will stress the machine further and can only take away so much material due to its digging limitations from bucket size.

Simply put the mchine will dig as fast as it possibly can but the carry away buckets and conveyor belt are the limiting factor.

The above does not consider break downs until they happen:

broken bucket teeth, broken buckets, bucket wheel bearing failure, broken wire ropes, broken gear teeth and many other items.

I guess I look at it this way:

If the seam is exposed for a huge area even larger than it is currently done using the road miners will be more of an advantage simply due to ease of mining with out benching/terracing by opening up the seam and reclaiming it using the method I described with the snow blower or a dozer to feed the stockpile for the reclaimer. the beauty of using the snow blower is nothing is lost or left in the seam from spiller over from a dozer blade or earth slides next to the seam edge.

The problem you have is the radial cutting and reclaiming width of the BWE and there is no getting away from that part of the algebra problem/physical limitation and terracing/benching is the result due simpy to the boom length of the BWE

The road miner and the diesel powered snow blower is the way to solve this in my opinion simply due to the simplicity as the amount work is reduced for mine design and eliminating space limitations due to the BWE size and reach-hence the teardrop excavation.

with the road miner you are cutting and moving at the same time versus the numerous steps for the BWE since you will dig to the BWE limitations of reach and then have to move and restart the process all over again and again and move up the the follow conveyor.

Do a time study using actual production rates attained with the BWE versus the road miner from actual rates obtained using the road miner including the moving time set up and repetition and you will see a big difference between the two favoring the road miner the road miners are used for surface strip mining as an actual benefit.

your turn ■

Greetings we are in for a huge sea change as far as the weather goes here in the eastern wilderness @1140 feet above mean sea level.

First rule of thumb:

the contact list of the various magazines will list all the officers on the mast head and this where your registered letters hould go.

Any correspondence should be in writing to the chair of the department or departments with certified or registered post.

Second;

All a BWE is is a water dredge on tracks-look at some of the old dredges used in the excavation of the Suez canal and the early beginnings of the Panama Canal and you will see why I say this as a continous bucket system was used for excavation and carry off of spoil.

The jet dredge and the cutter head dredge is an out growth of the above.

The currnent class BWE is simply modified with a conveyor for carry off of material. If my memory is still right they have several of them working the tar sands in Alberta, Canada so

contacting the folks at Sun Oil Company and the numerous canadian tar sands miners/petroleum will be in your best interest.

Google canada mining in parenthesis and you should come right to the government web site.

If you would like I will get the names of the chairs for you so you can contact them directly through corresspondence by overseas registered post.

A few dollars per letter may mine you huge dividends in research.

As i said before and I will say it again the United Staes Army Corp of Engineers is your first stop!!!!!!!!! they will help you as they do huge amounts of prep work for water jobs.

Ask about the Tom Bigbee waterway and all the rehab work done on the missisppi to date including the laying of concrete panels in the river bed in various places to reduce scouring and history on thier dredging program for all the navigable water ways.

The Government of Israel:

The local Israeli consulate in Victoria state-if they maintain one

They will be a great bunch to talk as they have used a dry cross channel dredge on tracks to excavate bomb shelters-look for excavating contractors in Israel.

Two other good places are are Wilfley and sons pump and Gould

pumps in Seneca Falls New York USA which is a short drive from my part of the eastern wilderness.

look for calls for papers at mining congress web sites regarding mining methods using dredges/ bucket wheel excavators etc. the mining schools will have them.

Also please contact the chair of the mining school at University of Texas El Paso as another source.

My dear friend you are not lost, your compass has not been calibrated thats all :^)

first:

google in ()

Rhinebraun consulting group:

go to www.coaltranportationinternational.com

they are listed in a paper done by queensland mining

This is just like buying a good used mercedes diesel motor car-you have to know where to look.

You have been given a thankless task that can be solved as your

managers are also unfamiliar with it.

its always a case of actual performance versus claims no matter the circumstance simply because the performance of the BWE units are declining in relation to expenses such as mine overhead and time and are not remaining competive.

Just out of curiosity are you dealing with a mine mouth power plant?

I ask this simply because if the haul distances are more than one mile2 Kilometers a capsule pipeline will cost less than a conveyor to operate-2 cents per ton mile.

lzaharis ■

Contact Board of directors member Melvin Benson at

www.suncor.com

The only nmber I have is for investor relations Mrs. Gail Clayton @ 403- 269- 8742

Mr. Benson or rather his secretary should be able to direct you to the operations/ engineering department very easily up there.

Dont forget they are not excavating as deep as you are in in victoria state versus the tar pits and oil sands handlling characteristics behave much differently than sub lignite, lignite, or sub bituminous as the sands are very very oily versus dry lignite.

Have you contacted anyone in Queensland state about their coal mining operations?

lzaharis@lightlink.com ■

Since my first posting was lost:

are you intending to mine underground with a BW excavator-not a really good idea.

you have not mentioned the type of overburden above the coal seam and it thickness this is the primary factor

a bucket wheell excavator wil require you to have a conveyor behind it or a conveyor system elephant walk style.

Electrical power may be up to and including 6000 volts using a quarry switch gear and transformer towed behind the bucket wheel excavator.

You have not mentined the coal type-

The coals mos or rockwell ratings for hardness.

Have you done any coring to obtain representative samples and done hardness testing?

what about methane detection and monitoring will you be drilling pre mining drainage holes to reduce the possibility of explosion from the actual act of excavation?

Is the the coal type:

sub lignite

lignite

sub bituminous

bituminous

metaurgical grade high BTU bituminous for steam or steel making

sub anthracite

anthracite

How deep is the coal seam?what is the height of the coal seam or seams?

are their multiple seams in the coal bed you wish to mine?

Is the top of the coal seam mudstone/shale/or limestone?

Is the floor of the coal seam a mud bottom or a rock bottom with sandstone or shale etc?

If you use a BW reclaimer for coal extraction it will be much more stressfull on the machines components-slewing frame dipper arm/cables/ motors / gear boxes.

How much overburden do you have to deal with? how far do you need to carry the top soil and spoils to storage. will you be reclaiming the mined area for reuse or leaving it to waste.

what is the backround radiation level after the seam has been opened?

How will you extract the overburden? transfer it from the overburden layer above the coal seam?

Will you be reclaining the overburden with out saving the top soil for reuse? bad idea!!!!!

The hardness rating for the coal will be the deciding factor as you may end up blasting it free.

You need to do a lot of leg work before you can even think about extraction methods.

e-mail off the board for more help if you would like to at: lzaharis@lightlink.com ■

Since you are dealing with lignite in multiple seams this is a bit of a problem relating to maintaining product quality and avoiding mixing the spoil with the lignite especially in the case of a bucket wheel reclaimer which will take everything in an all or nothing extraction mode of operation

It can be done but cleaning the lignite is the problem is the spoil

is mixed in with the lignite.

this is where the beaty of a mass rock excavator comes in:

For example:

The trencor 1660 Road Miner is capable of excavating a trench six feet deep and sixteen feet wide as an option.

this unit is diesel powered and has a mechanical drive system.

With it you will be able to take the clean lignite coal in repeated

passes in each individual seam with no worries about spoil entering the product stream.

The road miner can just dig the coal out and dump it to the side and it can be reclaimed or pushed of the edge of the seam to be reclaimed later.

It will also take the spoil and remove it and cast it aside to be removed later and in the process expose the top of the lignite seams individuall when seam depth is reached.

Where it can begin mining it and excavating the lignite to be mined out of the coal seams in repeated passes keeping the lignite free of spoil.

The use of a mass rock trencher reduces equipment cost and maintenanance and with lignite you will have a longer cutting bit life cycle as well.

It will be a lot less money and less maintenance and no requirements for electric power as it is diesel powered over mechanical drive and the smaller strip mine sections and soft ground will lend it self easily to the use of the mass rock trencher.

adding an incline/decline for access to the seam will work well in developing the seams as the incline will drop with the lignite seam depth.

I have provided a link below for your use for parent company which is Astec

And there used rebuilt mass rock excavators available for purchase from (Trencor or HL Chapman) so this is an option as well.

www.astecunderground.com

I do not represent trencor or astec underground. ■

since my posting was lost again.

Greetings until you do a time study with current machineries you will still be lost in the wilderness with out any useable data.

The trouble is in the accounting/machinery life/life cycle costing/depreciation and the bear hiding in the closet is time.

You have not even discussed the age of the reclaimers.

And as I explained before the road miner is more versatile with much less set up time-as I explained in my post that was lost:

The entire seam can be opened up on an incline at one or two percent and the road miner or any number of road miners can run in loops to take away the coal seam. very easily with no special prep work other than an initial incline to develope the seam.

The coal will be cast aside by the road miner and it can be reclaimed by the BWE later after the seam section is totally xcavated by the road miner and extending the life of the BWE as it will only be used in a reclaim mode.

A lazy/smart mans way to move the coal from excavation to the edge of the pit is to use a snow blower-(in all seriousness)

diesel powered snow blowers are tested using stone aggregate

to simulate ice and snow.

You should contact the Astec folks and HL Chapman about the road miner as it will save you time ands money and increase net income from reduced expenditures for mining. as i explained the road miner can mine a trench 6 feet wide and sisxteen feet long continously excavating almost 11, 000 cubic meters in one pass with no set up excavations. ■

since my posting was lost again.

Greetings until you do a time study with current machineries you will still be lost in the wilderness with out any useable data.

The trouble is in the accounting/machinery life/life cycle costing/depreciation and the bear hiding in the closet is time.

You have not even discussed the age of the reclaimers.

And as I explained before the road miner is more versatile with much less set up time-as I explained in my post that was lost:

The entire seam can be opened up on an incline at one or two percent and the road miner or any number of road miners can run in loops to take away the coal seam. very easily with no special prep work other than an initial incline to develope the seam.

The coal will be cast aside by the road miner and it can be reclaimed by the BWE later after the seam section is totally xcavated by the road miner and extending the life of the BWE as it will only be used in a reclaim mode.

A lazy/smart mans way to move the coal from excavation to the edge of the pit is to use a snow blower-(in all seriousness)

diesel powered snow blowers are tested using stone aggregate

to simulate ice and snow.

You should contact the Astec folks and HL Chapman about the road miner as it will save you time ands money and increase net income from reduced expenditures for mining. as I explained the road miner can mine a trench 6 feet deep and sixteen feet wide continously excavating almost 11, 000 cubic meters in one pass with no set up excavations simply based on you explanation of the coal seams exposure for mining- this amounts to 144 passes with one road miner or 77 with two road mners or 48 passes with 3 road miners in this ore block and it is coal that is already to be crushed as it is very fine finely cut

Mining an ore block whether it is underground or on the surface makes little difference as it still takes time, labor, and expense.

THE SIMPLER IT IS THE EASIER IT IS TO DO!!!!!!!

So if you exposed an ore block of that size the road miners could shave off succesive layers from end to end by creating slopes on both ends of the ore block and driving from one end to the other shaving off layer after layer taking the slopes with it until it is gone. ■

I can't believe the amount of discusion without even coming close to answering the question.

Yes drop cuts are possible with a bucket wheel excavator and such is typical during the mine development when a new lower level must be initiated and developed. For drop cutting the buckets must be removed and reinstalled flipped to the opposite direction. The bucket wheel must be driven in the opposite direction.

You must contact the experts, at the companies that make these machines, for advice. You have already listed the big names in this field.

Good Luck,

Joseph A. Dos Santos ■

Normally, BWEs should be in the position to dig either in terrace cut or in drop cut without major influences on the durability of the machine structures.

Drop cut may even improve in harder materials the stability of the machine, since maximum forces act more or less along the boom direction rather than vertical to it and thus causing oszillations.

While digging material deposited in stratified layers it might also be recommendable to use this method. While finishing the cutting of a slice at it largest cross section in terrace cut it is difficult to control the lump size at the top.

The terrace cut is usually, however, the more effective way of operating a BWE and, respectively, the most widely applied method.

With regard to the floating dredgers one should have a little closer look to the different technologies. They may have had something in common 150 years ago but comparing an IHC dredge today with a TAKRAF BWE will not show many similarities.

When comparing a BWE operation with a road miner or similar machine the overall picture including material loading and transport needs to be considered. One of the advantages of the BWE is that the material is fed directly onto belt conveyors for transport without requiring any further loading or feeding operation. Moreover, given today rise in fuel costs the use of electric energy may not be considered a disadvantage by many miners.

So, to summarize: a drop cut is not a problem for a BWE and can be done if necessary, but in general the terrace cut is the more efficient and hence more common operation mode.

Holger Lieberwirth ■