Rat holing problem

vibrating modules such as built by Silexport Intl will resolve the matter. Solution consists in placing modules on 4 sides of openings. All material above the angle of repose is instantaneously sheared off, starting from the bottom edge of the modules. Let us have size and distance between openings, your Email address and we shall promptly forward preliminary design.

Kindly mail to jcp.silexport@wanadoo.fr

Regards

Jean-Claude Poncet

Silexport International

www.silexport.com ■

Aside from activating the bottom region of the rat hole, as indicated by others, there is another possible procedure that may significantly improve the draw down angle. Please email me, noted in the below contact, if you wish further discussion. ■

Air cannons are a good possibility for this problem but I will freely admit I am no expert. but with fine material it needs to be forcibly moved.

lzaharis ■

If you know the reason why it builds up, this might be the clue to minimize its presence. ■

Walt

1. Have you got the material tested to determine the critical rathole DIA? - that would give you the idea about the chute sizes.

2. There is an article by Albert Maton about vibrating chutes-attached.

3. Rotary plough?

Attachments

stockpile-vibratory discharges (PDF)

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Here is a product we have been producing for over 40 years... it is a combination pile activator / feeder / flow control device and works exceptionally well. It was originally designed to solve issues like you are experiencing.

General Kinematics Un-Coaler Activator/Feeder is a state of the art solution to feeding and metering material. The Un-Coaler combines the performance of vibratory feeding with the benefit of integrated flow control.

Vibratory bulk material reclaim has never been so dependable or versatile for rates up to 2,000 tons per hour. The Un-Coaler combines the flow control characteristics of a totally enclosed vibrating feeder with proven bin activation. Since the unit discharges material vertically to conveyor below, loading is always centered and symmetrical. This feature helps to eliminate belt tracking problems common to side feeding. The Un-Coaler also helps eliminate bridging and other issues found with other metering options.



FEATURES

Low headroom design for reduction in installation requirements.

No gates required.

Symmetrical and centered loading.

Eliminates bridging.

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In case this problem is still pending, we have a solution to propose. It consists of vibrating modules placed around the openings. Silexport International is in the process of installing such a system under a mine stockpile. Kindly contact us for more details

Silexport International

silexport@silexport.com

www.silexport ■

If you put hats between each discharge you will activate the stockpile over the entire length. ■

You do not have an adequate structure to support several vibrators. You do have 3 structures buried up to their necks in sand right next to the tunnel. That is a major part of the problem.

The natural outcome of offsetting the tunnel from the shuttle conveyor also means that a large, very large, proportion of the pile is dead anyway.

Nature has been on your side so far. If you improved the extraction you might develop walls that will push the structure around as they collapse.

I've seen a small bin, lined with HDPE, with steep enough hopper walls to boot, which wouldn't pass damp sand over a vibrating feeder despite a lot of angry poking from above & beneath. Sometimes its like starch.

All these factors suggest that you should have stuck it out with the front end loader. It is the only true way to load trucks with bulk. Why? Because while a truck is getting into position you have to stop the flow & store it somewhere small. Like a truck body for goodness sake.

Plant design is about 40 years behind. Everybody else maximises the transport system storage capacity, except mines & quarries. Why produce it if you can't shift it? ■

You've got a big pile of stuff.

You need to load it into lorries.

Drive lorry to the pile, drive front end loader to lorry and pile, use front end loader to move stuff from pile into lorry.

Simple! If your front end loader fails, hire in another. You can always hire a front end loader to start with. ■

Originally Posted by designer

You've got a big pile of stuff.

You need to load it into lorries.

Drive lorry to the pile, drive front end loader to lorry and pile, use front end loader to move stuff from pile into lorry.

Simple! If your front end loader fails, hire in another. You can always hire a front end loader to start with.

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Designer;

I am wondering if the problem was solved for him by the upper management and

that is why we have not heard anymore from him about his sand pile?

lzaharis ■

Originally Posted by lzaharis

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Designer;

I am wondering if the problem was solved for him by the upper management and

that is why we have not heard anymore from him about his sand pile?

lzaharis

I think the problem was solved when the wall fell down: taking the shuttle conveyor with it. ■

Don't know if you have solved your issues as yet. I believe a low cost product will solve most issues with material rat holing due to moisture and packing in silos, hoppers or chutes etc. I am in the process of solving more of these issues using Cardox (a high pressure gas breaking system) that costs about $2.00 an activation use to aerate and clean the chute walls without any vibration or damage of any sort. The uses are exceptional and is even used in cement kilns to break up packed clinker and calcium without damaging the refactory bricks lining the rotary kilns. Vibrators can be more problems than they solve as they compact the product harder rather than free up its movement. On the Cardox side, it was designed for firery coal extraction and has been dramatically improved since its inception in 1927 to be a fantastic product that has so many uses. The website is http://www.cardox.co.uk ■

Originally Posted by tecmate

...Vibrators can be more problems than they solve as they compact the product harder rather than free up its movement. On the Cardox side, it was designed for firery coal extraction and has been dramatically improved since its inception in 1927 to be a fantastic product that has so many uses. The website is http://www.cardox.co.uk

Agreed. Now we know where they got the idea for airbags in vehicles. Notice that the inception date of 1927 can be positively considered against the webpage header mentioning Patents Pending. Theirs really is a policy of continuing improvement.

Its also gratifying to note the Ashton-under-Lyne remains in Lancashire.■

Originally Posted by tecmate

Don't know if you have solved your issues as yet. I believe a low cost product will solve most issues with material rat holing due to moisture and packing in silos, hoppers or chutes etc. I am in the process of solving more of these issues using Cardox (a high pressure gas breaking system) that costs about $2.00 an activation use to aerate and clean the chute walls without any vibration or damage of any sort. The uses are exceptional and is even used in cement kilns to break up packed clinker and calcium without damaging the refactory bricks lining the rotary kilns. Vibrators can be more problems than they solve as they compact the product harder rather than free up its movement. On the Cardox side, it was designed for firery coal extraction and has been dramatically improved since its inception in 1927 to be a fantastic product that has so many uses. The website is http://www.cardox.co.uk

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please do no more advertising on this thread!!!!!!!!!!!!!

This problem has simply boiled down to a basic numbing first semester geology issue:

Residual water allows compaction of any in situ dirt, and why some soils are so hard due to rainwater penetration and SETTLING in situ.

Sand is no different and it continues to compact upon itself until it reaches the point it can no longer move downward and the water simply drains away in the nearest available channel.

This has been the issue from the beginning and he has not advised any of us of the progress if any. ■

Originally Posted by tecmate

Don't know if you have solved your issues as yet. I believe a low cost product will solve most issues with material rat holing due to moisture and packing in silos, hoppers or chutes etc. I am in the process of solving more of these issues using Cardox (a high pressure gas breaking system) that costs about $2.00 an activation use to aerate and clean the chute walls without any vibration or damage of any sort. The uses are exceptional and is even used in cement kilns to break up packed clinker and calcium without damaging the refactory bricks lining the rotary kilns. Vibrators can be more problems than they solve as they compact the product harder rather than free up its movement. On the Cardox side, it was designed for firery coal extraction and has been dramatically improved since its inception in 1927 to be a fantastic product that has so many uses. The website is http://www.cardox.co.uk

====================================================

Its ironic that they simply did not reduce the pile height and weight to begin with.

Any explosive could not be used simply due to the danger of cave ins during the placement of it by the employee- having no human accessible draw points for charge placement.

its not like or as easy using a helium balloon to carry dynamite in a blocked ore pass draw point 200 feet up in its throat.

And the energy shock wave would be quickly dissipated due to the porosity of the sand and water weight.

in other words a thud and a dud.

Cardox on this side of the pacific pond is fifty to seventy times as expensive as your claimed cost from the national distributor as 4 foot single charges are over one hundred dollars USD

With no communications from the original poster about the issue, one could assume they have a tracked excavator with a long boom and dipper or simply knocked the pile down to a manageable height and use a small dozer to push sand into one draw point and eliminate the insanity. by reducing the pile weight and compaction which is what we have been throwing at this "Nerf dart board in the darkened room wearing a blindfold" example. ■

Originally Posted by lzaharis

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please do no more advertising on this thread!!!!!!!!!!!!!

This problem has simply boiled down to a basic numbing first semester geology issue:

Residual water allows compaction of any in situ dirt, and why some soils are so hard due to rainwater penetration and SETTLING in situ.

Sand is no different and it continues to compact upon itself until it reaches the point it can no longer move downward and the water simply drains away in the nearest available channel.

This has been the issue from the beginning and he has not advised any of us of the progress if any.

Dear lzaharis, I am sorry if you think I was advertising but I was not doing so. First point of interest. I merely pointed to a site that has a product that is cheap in the reuseable tubes, less that US$2 of consumeables per activation, I don't know where the US$100 on this side of the Pacific costs come from as the setup the tubes is around $2 Australian[Carbon Dioxide liquid, Heater, 2 fibre washers and a rupture disc.] If you were hiring the rod tubes, as a single one off hire, then I could understand the hire costs per tube. When rat-holing is an ongoing issue to deal with, the simplest and possibly cheapest scenario would be that one would purchase the whole Charging Station, Tubes and Collets and have them for around US$40,000 complete except for consumeables in an ongoing use. Second point of interest. Also, one would place the collet/s in the floor of the drawdown Vault away from the discharge point where the product would pack, as a permanent fixture and simply insert the tube when required to aerate the sand and allow free movement. NOTE:- Your comment on the cost would be very off-putting to anyone who wished to use a product for this application or similar applications. It helps if you have your figures correct before stating something that is completely untrue about the costs. By way of information, I am NOT a salesman or a franchisee holder of the Cardox product. But as a Trainer / Assessor, this was a small part of my mechanical field until I retired last year and I am passing on this information for the benefit of everyone.

Regarding the volume of the stockpile, there are operations here that have many multiples of the size stated and they operate successfully. Packing and rat-holing is an issue, but I cannot state how the individual companies deal with the issue. All I know is that that I have been asked to supply my training packages for Cardox to a number of companies for their use. As for the use of explosives, I am an ex-[explosives 'Powder Monkey' & quarry owner] and Cardox is a much better OH&S product. ■

Originally Posted by tecmate

Dear lzaharis, I am sorry if you think I was advertising but I was not doing so. First point of interest. I merely pointed to a site that has a product that is cheap in the re-useable tubes, less that US$2 of consumables per activation, I don't know where the US$100 on this side of the Pacific costs come from as the setup the tubes is around $2 Australian[Carbon Dioxide liquid, Heater, 2 fiber washers and a rupture disc.] If you were hiring the rod tubes, as a single one off hire, then I could understand the hire costs per tube. When rat-holing is an ongoing issue to deal with, the simplest and possibly cheapest scenario would be that one would purchase the whole Charging Station, Tubes and Collets and have them for around US$40,000 complete except for consume- ables in an ongoing use. Second point of interest. Also, one would place the collet/s in the floor of the drawdown Vault away from the discharge point where the product would pack, as a permanent fixture and simply insert the tube when required to aerate the sand and allow free movement. NOTE:- Your comment on the cost would be very off-putting to anyone who wished to use a product for this application or similar applications. It helps if you have your figures correct before stating something that is completely untrue about the costs. By way of information, I am NOT a salesman or a franchisee holder of the Cardox product. But as a Trainer / Assessor, this was a small part of my mechanical field until I retired last year and I am passing on this information for the benefit of everyone.

Regarding the volume of the stockpile, there are operations here that have many multiples of the size stated and they operate successfully. Packing and rat-holing is an issue, but I cannot state how the individual companies deal with the issue. All I know is that that I have been asked to supply my training packages for Cardox to a number of companies for their use. As for the use of explosives, I am an ex-[explosives 'Powder Monkey' & quarry owner] and Cardox is a much better OH&S product.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The way that disaster is set up it was gong to continue have trouble simply due to the design of the system and the added draw points as it only compounded the problem (IMO) we don't even know if it still working!!!!!!!

As the draw works is smaller than the pile diameter its a sure thing the inverted cones draw works will cause nothing but problems-if you have looked at all the threads we have mutually posted.

The design has lost all its mechanical advantage due to pile height small size of draw works. The inattention to pile size in relation to the poor draw down problem is another landslide and potential man killer.

Adding slip liners will work for a while until the sand stops moving and the craters are reestablishing themselves as are the only funnels when they work. Gravity works sometimes but not ninety percent of the time.

By now they may have added air lance holes to the chutes but the poster has offered no additional information.

Any sand will behave like casting sand if compressed mechanically or simply by weight which is why I brought up the first semester geology example.

I have done my share of transporting explosives and done the daily inventory of stick powder, amfo, blasting caps, cap boosters, fuse cordage, zap cordage

manually making blasting fuses loading stick powder and anfo so I am no stranger to explosives end of the mining business as much as i dislike amfo personally.

I was quoted over one hundred dollars for 12 foot tubes, plus collets, rupture discs, wiring, heaters etc. by the United States distributor in Ohio as I was intending to do underground dynamiting on a custom basis and that is why I said what I said, so no one is wrong in either case.

The fact remains their loss of mechanical advantage using brute force is ignored simply by not using a small tracked excavator and or dozer with no loss of production. not much different than a mud suction problem and too small a machine to remove the mud the machine can not dig a bucket of mud but it can pull itself over trying to do so because of the compaction.

Louis and I pointed out very adequately(I thought) that using a small dozer and pushing to the end for drawing would solve this. and create a larger stock pile to work with and from.

lzaharis ■

I don't think the thread starter is there any more. After some quite presentable 3D models we've heard nothing. He's probably moved on & left the mess behind. Like he said it was poorly thought out so there might be a lot more wrong with the plant under discussion. Let's wait & see.■

Beunos dias Luis,

You have not discussed or elaborated on the screening plant

or rescreening plants for oversize material and whether a secondary

screening and crushing loop is to be employed OR Whether the sand is washed sand as well.

As the base of the stock pile is 50 Meters/164 feet the issue is the

height which is also unknown which is of course (X).

SO if the stockpile is sixty feet high and 159.16 feet in diameter using

sand as an example you will have 14,775 yards and a tonnage of

Wet sand as an example is 120 US pounds per cubic foot,

14,775 US cubic yards;

398,925 cubic feet rounded to 400,000 cubic feet;

48,000,000 pounds;

24,000 US tons;

As you have seen in the example poor planning results in the problems illustrated in the images

The problem is we have too little information.

Help us to help us help you!

You have not mentioned the tonnage per hour of the screening plant nor t

he tonnage per hour of cut washed or unwashed sand product or products.

Nor have you mentioned the screening plant and or crushing plant that will

feed the stock pile and last but not least the sand screening cut size(s).

Nor the type of sand and whether it is a wet or dry gravel sand or a

stone sand or what the rock type is if it is a stone sand or a

concrete sand with stone or a fine cut mason sand or a

fracking sand which will affect the bulking factor and weight

per cubic foot in the pile the pile will be at least 60 feet high.

The issue is and will continue to be the drawdown of the sand and the

type of machinery used for the drawdown of the sand.

Many gravel plants simply have an off feed stacking conveyor that centers the pile at one point and they have a

concrete gabion block wall to hold the stock pile in place and it permits the use of a rubber tired loader to

reclaim the pile.

The size of the stockpile is the issue as reclaim will be one of cost and time and what you can afford.

If your simply looking for drawdown point examples visit the CEMA web site.

Big stockpiles are huge problems unless you intend on using brute force to reclaim them.

Belt feeders and apron feeders are limited to the size of the cone of depression created

when drawdown occurs.

A stockpile or or continuos surge pile will create a cone of depression or cones of depressions

which is well illustrated in the images and the results of poor planning OR lack of funds are sadly evident in the images. ■

"We are designing a conical sand stock pile 50 m dia. with tunnel reclaim system.

Please, comment me your experience."

You have read about the problems faced with trying to handle damp sand so why are you following the failed principle once more? In fact your situation will be considerably worse, if you have multiple drawdowns the outer ratholes will just be smaller.

Obviously your plant management is awash with surplus CAPEX and needs the expenditure to add credence to next years budget. Been there: seen that!

You are spending money on a conveyor and take out system that you admit might not work, won't work well at best, rather than lashing out on a hired wheel loader or 2. Sorry to be so blunt but that is what happens when quarrymen get rich. Someone once wrote "Why produce it if you can't sell it?" It's not as if the sand was going to get up on its own and walk to market. ■

Guys - Luis has only copied what the original poster posted (including pics) and has asked if it was ever resolved.

He made an error when quoting the original poster and removed the first part of the syntax so I fixed the syntax to show the quoted part of his post.

Also considering the fact that the original poster walthcm was a guest at the time and never registered I doubt he will be back to add more to this thread as it is 4 years old now. ■