Coal Handling Problems

Posted in: , on 23. Jun. 2006 - 11:22

Coal Handling is a very difficult techology; the oxydation of coal at stock yards, the flow problems during rainy seasons, sticking problems at shutes and bunkers, problems combined with mixing different sized and different quality coals, the abrasion of coal handling equipment, spillage during handling etc...

I would be happy to hear such problems and solution examples from diffuclt cases and discuss the coal handling technology problems, if any exist.

Re: Coal Handling Problems

Posted on 23. Jun. 2006 - 08:15

Dear Dr. Ergun,

Sometimes, lignite is also mentioned as coal by some people. The characteristics of lignite and black bituminous coal are quite different and the design of the coal handling plant for these materials is also remarkably different. For example, lignite can be quite sticky and can become somewhat muddy in a wet condition but black coal will not become so sticky etc. Although black coal is comparatively hard but the abrasive index of lignite is often more, due to inbuilt sand content. So, it is advisable to be specific whether the coal handling plant referred here is lignite handling plant or black bituminous coal handling plant.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916

Re: Coal Handling Problems

Posted on 24. Jun. 2006 - 11:11

Coal is coal & lignite is lignite. Where's the issue? Where does technology, as we understand it, come into coal handling?

John Gateley johngateley@hotmail.com www.the-credible-bulk.com

Re: Coal Handling Problems

Posted on 5. Jul. 2006 - 01:46

Dear Mr. Ishwar Mulani,

Thank you for your kind remark

You have perfectly right if you say, that lignite/brown coal and bituminous coal/hard coal should be separately treated;

the same counts also under the hard coals sorts that for example anthracite and fat coal as well gasflame coal.

Mechanical Process Technology

Posted on 5. Jul. 2006 - 01:58

Dear Mr. Johngateley,

Thanky you for your comment.

The technology, around which it acts itself in the coal treatment and preparation, is the mechanical process technology.

To this however also the chemical process technology arrives.

Furthermore the thermal process technology is also of importance. Biological and metallurgical process technology are further zones that come here into question.

Thanks

Die Technologie, um die es sich bei der Kohlenbehandlung und - Aufbreitung handelt, ist die mechanische Verfhrenstechnik. Hierzu kommt aber auch die chemische Prozesstechnik hinzu. Ferner ist die thermische Prozesstechnik auch von Bedeutung. Biologische und metallurgische Prozesstechnik sind weitere Gebiete, die hier in Frage kommen.

Vieen Dank




Originally posted by I G Mulani

Dear Dr. Ergun,

Sometimes, lignite is also mentioned as coal by some people. The characteristics of lignite and black bituminous coal are quite different and the design of the coal handling plant for these materials is also remarkably different. For example, lignite can be quite sticky and can become somewhat muddy in a wet condition but black coal will not become so sticky etc. Although black coal is comparatively hard but the abrasive index of lignite is often more, due to inbuilt sand content. So, it is advisable to be specific whether the coal handling plant referred here is lignite handling plant or black bituminous coal handling plant.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916

buffrock - RCAI, USA
(not verified)

Coal Handling Problems

Posted on 22. Jun. 2007 - 07:28

Soy-based release agents work very well with sticky ores, oil sands and asphalt. Recent experience at a Phelps-Dodge mine and a Penoles one in Mexico would indicate Alderox has potential to work efficaciously in a wide variety of material handling situations, even freezing conditions in rail cars, equipment and chutes. By all mean give our VP Mining Operations Vivien Hui a call at 303-502-0025 for technical details.

Re: Coal Handling Problems

Posted on 12. Jul. 2007 - 04:21

Coal Handling? try us with our bulk conveying and handling machinery!

We are specialized in Bulk Conveying & Processing Machinery. www.krdbulk.com Jimmie Jia Sales Assistant Tel: 0086-(0)21-68509660 Fax: 0086-(0)21-58859407 Mobile: 0086-£¨0£©13564088704 Mail: jimmie@krdbulk.com

Coal Flow Problems

Posted on 12. Jul. 2007 - 02:42

There are many coal storage installations that experience flow problems, particularly when handling fine coal that is moist. Retrofits usually have to accomodate a variety of constraints, but measurement of the flow related values and exploitation of established design methods and techniques to improve flow channels can usually bring about a radical improvement. Recent modifications to a 4,000 tonne hopper system, with wall not considered strong enough for mass flow, converted an operation plagued by flow stoppages and ratholes to a reliable discharge by transforming the flow channel in the outlet region and then expanding the path to be greater than the critical rathole diameter.

Apart from historical installations, it is remarkable that some large hoppers are still constructed without being based upon quantified flow values of the the material to be stored or employ a single form of geometry and wall inclination for the whole hopper section. Structural strength is always taken into account, but refinement for optimum flow seems to receive far less consideration.

Re: Coal Handling Problems

Posted on 1. Aug. 2007 - 10:08

In theory it should be possible to design a handling system according to the coal to be handled. i.e. the coal from a particular seam or a specified grading from outside sources. Unfortunately operating conditions can vary wildly which are usually the cause of problems on a otherwise well designed plant.

The rush of water during the start up of an underground operation after maintenance day is one example. This puts paid to the best designed bunker etc. Likewise when the slurry reaches the surface, the effects on sample plants bins, transfers and stockpiles creates additional headaches. De-watering facilities usually underestimate the instantaneous quantity of water on the belts in these conditions and fail in their task to efficiently dewater. Generous de-watering systems designed for peak water flow (without coal) should therefore be installed.

Stockyard belts are generally open topped for both stacking and reclaim. The cost of covers suitable for catering for the stackers and reclaimers is generally prohibitive. This raises the question of what to do in a thunderstorm. The options here are run the belts empty and stop them followed by dewatering of the belts (not to good for production) or run the belts at maximum capacity. The quantity of water discharged at the head of a long open conveyor can be horrific during a thunderstorm. Calculate the catchment area of the belt, the belt speed and the litres/second at the discharge. If the belt is running empty the water is a problem and will spill on any incline. Coal sent before the water has cleared the system will fluidise on an incline causing spillage (and collapse of the gantries if allowed to spill often enough). If the belt is lightly loaded, the coal will fluidise on the incline inclines causing spillage. If the belt is fully loaded the ratio of coal and water can be maintained within acceptable limits. i.e. no spillage or runback.

Engicon specialises in correcting non-performing plants and low cost de-bottlenecking of systems.

Re: Coal Handling Problems

Posted on 11. Feb. 2008 - 12:50

All aspects of the coal dust industry which is really what you refer to are found on www.cypherltd.com under Dust Stop. Good luck and please be assured that the product is exceptional and is used by the worlds largest coal company and the largest construction site on earth.

Norm Burns

Norm Burns

Re: Coal Handling Problems

Posted on 7. Aug. 2008 - 06:07

For discharging stubborn ratholing and bridging coal from bunkers:

http://www.navco.us/files/1000.010%2...or%20Power.pdf

For unclogging coal chutes and pipes:

http://www.navco.us/pipe.html

For unloading rapid discharge coal railc ars completely:

http://www.navco.us/hopper-car-unloa...s%20video.html

YouTube Videos of Railcar Unloading difficult coal:

http://www.youtube.com/watch?v=Kl1YjkXmOqk

Did you know Pneumatic Industrial Vibrators are safer than Air Cannons and Blasters for discharging coal for several reasons? This article explains why:

http://www.navco.us/pneumaticvscannon.html

There are two basic types of vibration that can be applied to storage vessels such as bins, hoppers and railcars as flow aids. In this article the differences and advantages or disadvantages of each are described:

http://www.navco.us/vibrationcomparison.html

Tiffany Moore Two companies under one roof: http://www.navco.us Experts in Applied Vibration - Industrial Vibrator Mfg. and JVI Vibratory Equipment http://www.JVIVibratoryEquipment.com Vibratory Feeder and Screen Mfg. Call toll free for info: 1 (800)231-0164

Re: Coal Handling Problems

Posted on 8. Sep. 2008 - 06:17

Not everyone has the luxury of water. You may not have a water source or may need permits to pump water from source and handle the excess water into the water table or near by rivers, etc... We handle coal all year round. It's not very fun in the winter. Cap your coal for dust control with water daily (if available) or coat with liquid calcium or waste oils if prohibited. Calcium is expensive so you will have to manage piles closely to ensure piles are opened up and reclaimed right. No unnecessary traffic on piles once capped. In the winter we screen the coal to get rid of frozen lumps and keep material (fluffed up). Lots of heat around hoppers in winter. Like one of the prior posts, keep the product going, hoppers and belts full at all times. Scrapers! Scrapers! Scrapers! Oh yeah, a few well placed vibrators won't hurt.

Use Super Abrasion Beltings Or Chevron Belt

Posted on 27. Sep. 2008 - 08:47

Dr.Ergun,

Concerning with your abrasion problem in conveying coal, how about trying use super abasion beltings, for example, DIN W (abrasion 90 mm3 ), AS-1332-A (abrasion: 70 mm3),or using chevron belt,such as Chevron Height = 5mm, multi-V pattern, this pattern is very popular in our European clients and it did a good job in conveying coal, concrete and iron powder.

Hope that this can give you some valuable references.

Regards,

Molly

Qingdao Huaxia Rubber Industrial Co., Ltd.

E-mail: export@huaxiarubber.com

MSN: lemon316@hotmail.com

Re: Coal Handling Problems

Posted on 27. Sep. 2008 - 10:38

Originally posted by Dave Morgan

In theory.......

...... If the belt is running empty the water is a problem and will spill on any incline. Coal sent before the water has cleared the system will fluidise on an incline causing spillage (and collapse of the gantries if allowed to spill often enough). If the belt is lightly loaded, the coal will fluidise on the incline inclines causing spillage. If the belt is fully loaded the ratio of coal and water can be maintained within acceptable limits. i.e. no spillage or runback.

I recall a recent statement on the forum that water will run up a slope in the teens of degrees. I haven't looked up the exact figure because I still find it hard to believe. Ponding, particularly with coal, is disatrous to a conveying system, precious little is done about it and the topic is conveniently ignored in the available literature.

Re: Coal Handling Problems

Posted on 30. Sep. 2008 - 09:32

Dear louispanjang

Both statements are true.

Water will run up a steep slope, and will cause problems on a shallow slope. The problem in both cases is the length of time it takes for the water to clear. The water travels very slowly up a steep slope e.g.14deg but will eventually clear. Even on a relatively shallow slope (± 6º) the water may only travel at +-25% of belt speed, but this depends upon additional factors such as water volume and purity, initial dryness of the belt and of course belt speed. A simple way to test the water /belt speed ratio is to measure the time it takes the tail of the water stream to clear a section of the conveyor.

When no other information is available, I find the 25% rule reasonable to initially estimate the water volumes that will spill from the belt due to ponding and the time an empty belt should run before material can be added. No doubt others will have different methods of determining the true figures but as long as you consider the consequences of the water and cater accordingly you will remove or reduce an operational nightmare before it becomes a reality.

Engicon specialises in correcting non-performing plants and low cost de-bottlenecking of systems.

Coal Handling Problems

Posted on 31. Aug. 2006 - 04:08

Do you mean to handle coal without creating nuisance?

Coal can be transported in slurry form ( coal water mixture ). I used to work with this project before (pilot project) where you can mitigate the probelm of dust, upgrading the quality of coal (removal of high percentage of sulfur content and moisture content).

But to implement this method to the industry, the cost wise is become an issue (whether this method is feasible or not).

Rgds,

Leo

Thanks and regards,