Mining Industry 3

[pithpal]

Hi,
I got a call for a Company , who is in mining work and needs a jr. electrical engineer. Could you please advise me, what is special about mining as compared to Normal commerical power distribution.

Thanks

 

[itsmoked]

I would expect they are looking for someone who has some experience in power in the particular field of mining. And, understands "power" as it pertains to the Mining Rules (the document's name escapes me).

Keith Cress
Flamin Systems, Inc.- <

http://www.flaminsystems.com>

 

[ScottyUK]

Mining equipment typically is Flameproof (explosion proof to the US) and very specialised: transformers on rails, DC machines, high voltage in situations where you might not imagine it, huge ventilation plants, winding engines, locomotives, conveyors etc. In the UK there are an entirely separate set of regulations for mines and quarries because the working conditions are so different to those which apply to 'normal' industry.


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[pithpal]

Could you plz advise, where I could read about mining basic fundamentals and type of electrical system.Any website would work

Plz advise.
Thanks

 

[TMD]

pithpal: The type of mining is relevant. Coal produces gas when mined, so underground mining is special. Surface or hard rock mining is different. Google keywords to get up to speed. If they are looking for a junior engineer, they don't want to pay for a mining expert. Just be aware of the industry and give it your best in the interview. No one just out of school will know all that you can learn on the job.

 

[tulum]

Hello pith,

I am currently working in the mining industry (underground nickel mining). As ScottyUK pointed out there is a HUGE difference between electrical systems in mining and normal industry.

I believe in the coal industry flameproof equipment is a requirement because of the gas, however, in Nickel mining these rules do not typically apply. The basic premise from mine to mine is the same, however the conditions and equipment vary quite drastically. There is no industry quite like mining.

It has really only been in the last 5 years that mines in our area have allowed the Electrical Safety inspectors into the mines. It is a learning process for everyone.

If you want to gain some insight into mine power systems visit

http://www.msha.gov/S&Htopics.htm

... in and around there you will find some electrical articles. If that does not work let me know.

Good luck.
TULUM

 

[pithpal]

Thanks tulum,
The requirement of position says " experience in power distribution".
Plz advise me what kind of motors are used and what things I should conceptually stress upon, like for example
how grounding can be a different issue in mines than commercial buildings that is my ide of asking.
What do you mean by flame proof though.
Thanks

 

[tulum]

Pith,

Power distribution in mining is typically the same as anywhere else with a couple of exceptions;

(1) the mine is always moving therfore motors and other loads can creep up and need to be planned for... (increase short circuit)

(2) underground mines are resistance grounded usually to 5A, 10A, or 15A. This limits the amount of ground fault current.
(see startco's web site se-325 relay)

(3) trailing cable is used extensively in underground mines. This type of cable is used on LV and MV mainly because there is a ground check conductor in the cable. This allows a relay (such as the se-105 - startco) to check to see if the ground has been broken in a cable. This is useful when a mine power centre (see Metalec Sudbury Inc website) is used to feed a load further away. It is essential the integrety of the ground between the source and load is maintained.

(4) On surface power distribution is the same as anywhere else. However, underground the mine voltages as a rule are below 15kV. Above 15kv the equipment tends to loose its portability.

This does not encompass everything to do with mine power systems but it is a start.

Regards,
TULUM

 

[cuky2000]

The electrical principle for mine application is the same as any other power distribution system. However, the emphasis in mining is safety often associated unusual environment conditions such as wet, conductive dust, sometime explosive material, etc.

Other characteristics in mine application may be the mobility and quick deployment of electrical apparatus and equipment sometime operating at high altitude or deep underground exposed to heavy vibration or other nonstandard operating conditions.

In the US, the Mine Safety and Health Administration (MSHA) is a federal dependency of the Department of Labor that have jurisdiction over the electrical work in mines. For instance, any electrical equipment typically requires the submittal to the MSHA’s Approval and Certification Center (A&CC).

See the enclose link and search for more information

http://www.msha.gov/stats/top20viols/tips/12004.htmthere

is Federal organization

http://www.ipowersolutions.com.au/switchgear/brochures/switchgear/substation.html

 

[RalphChristie]

Hi pithpal

Can you state what kind of mine it is (opencast or underground) and what they are mining? I am working on an opencast iron ore mine on this moment but has also worked in an underground coal mine.

I agree with Tulum on many of his answers. All my answers are based on my own experience, and not necessarily the only way of doing things.

In the plants the electrical distribution is much the same as anywhere else. The different voltage levels are much depending on the size of the plant - on the mine I am now working the motors in the plant are up to 3.3kV, while in the coal plant where I have been it is just up to 400V. There are a big difference between electrical distribution in the pit/mining areas in mines and electrical distribution on other places. But the basic principles stays the same.

The distribution-method (cables, overhead lines, etc) are very temporarily. It shift almost every day, depending on where the mining activities are taking place. Overhead lines and cables for main distribution are 11kV, while trailing cables, depending on the machines, can be up to 6.6kV (400V, 525V, 3.3kV and 6.6kV)

Grounding method is normally high impedance grounding. Because there are no stationary ground point on a moving machine, it has to be grounded through the cable. Inside the trailing cables are a extra pilot wire/s - and like Tulum stated it is used with the ground wire to ensure continuity on the ground wire. This is a very important issue, because the machine must be grounded the whole time.

Due to the fact that the equipment moves continuously and is located in extreme conditions (wind, rain, sun, mud, dust etc, etc) the electrical panels are build very robustly. And like stated previously, flameproof equipment are also used sometimes, especially in underground mines (normally gold and coal mines) where there are possibilities of explosions.

Also remember - mines are not always the cleanest place to work!

Regards








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[pithpal]

Hi Tulum and everbody
I spoke to one of the mining manf. supplier.You mentioned name of this company in Sudbury. Do u work with INCO stuff.
I had a word with the guy and he told me about:
1. Booster Fans
2. Pumps.
3. Exhauts fans
4. Hoists.

I have a specific question and would appreciate , if you just pick the equipment in list above and advise me what kind of motors they use and other thing when it comes to their controls, Are they on ground and PLC operated?
What is the normal trend. I would appreciate a word from you.

Regards,

 

[jraef]

pithpal,
One thing you MUST take to this interview (should you get that far) is an ability to pay attention to detail. Twice you have been asked about what type of mine is being refered to, because the details can vary greatly. You have yet to respond, chosing instead to start asking about specific machinery that may not be used at all in the mining industry this employer is working in. People here have been trying to tell you that it makes a BIG difference.

I do a lot of work in the mining industry, but not coal for instance so I have no specific expertise in that area. What someone tells you about open pit gold mining or hard rock nickel mining can be completely different from coal mining or salt mining. Please try to find that out first so you don't go off half-cocked talking about irrelevent matters.

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[pithpal]

I apologize jraef. It is a nickel an copper mining in Ontario. I beleive it is at around some times 8400 ft and
4800 ft but not sure open pit or not.
I hope this is enough because this is what I know.

I think Nickel and Copper will not be an open pit.

Now can you throw some light on my question in earlier post about equipments. and this trailing cable: Is this a 3 conductor cable with neutral and ground in same cable? As I could not perceive that how cable will be routed in mines using EMT conduits or galvanizes conduits.
Please advise.

Regards,

 

[pithpal]

Hi Everybody,
My interview is very close, I would appreciate answers to my questions.
Thanks

 

[waross]

Hi pithpal
Good luck with your interview. At 8400 feet this will be underground (8400 feet underground.)
A trailing cable typically is laid on the ground and possibly dragged on the ground and feeds power to movable and relocatable equipment. Think Big Extension Cord, Really Big. In open pit mines it may supply large shovels, and/or draglines. It may supply a skid mounted, relocatable power distribution center. It may supply conveyors.
I haven't been around an open pit mine for a long time.
Check the links and do some googleing.
Remember that an itegrated operation may include milling and smelting. It is possible that a distribution engineer may be involved with milling, refining or smelting and never work underground.

try these web sites;

http://www.infomine.com/

http://www.minecableservices.ca/newdesign/products.html

http://www.minecableservices.ca/newdesign/cables.html

http://www.inco.com/

Good luck
yours

 

[ScottyUK]

pithpal,

Without wanting to be sound negative - and I wish you good luck in your interview - even if you bluff your way through the interview, what will happen if you get the job? You will be expected to earn a living in a mining environment, and if you don't know the basics about the industry and the methods it uses you will be in a very awkward position. If this is a junior position and your prospective employer is expecting to train you 'on-the-job' then the situation is different.

You might want to investigate some of the mining machinery manufacturers' websites. There are some with good photgraphs and explanations which will perhaps help you.

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[jraef]

ScottyUK, he said at the outset that it is a Jr. position, so your point, valid as it is, may not apply. We all have to get our experience somewhere.

pithpal,
here is a websirte of a company in BC that is very involved in designing and supplying equipment to that industry. Browse their Minimg section and take a look at what they offer for mobile switchgear and cable connectors, that can give you an idea of what you will be expected to work with.

http://www.uee.com/

Generally, mines identify themselves by their primary ore focus, but almost all of them extract everything they can from the excavation. So a gold mine may also harvest silver, copper, zinc, nickel etc., just depending on what is in the rock there. Being that your prospective employer identified itself as a nickel-copper mine, I would venture to say it is Falconbridge in Sudbury, which is an underground mine, not open pit. Trailing cables will be a big deal there, as will mobile sub stations etc.

http://www.falconbridge.com/our_business/nickel/operations/sudbury.htm

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[ScottyUK]

Thanks for pointing that out - I looked back and missed it completely. I owe pithpal an apology.

Here's one of the UK companies I'm familiar with - one of the few we have left following the murder of our coal industry by our 1980's government:

http://www.baldwinandfrancis.com/bfmining2.htm

The equipment in the metal ore mine in some ways could be very different - no flammable gasses to worry about - but the photographs might help show how the construction of mining gear is very different to surface equipment. The low profile and generally massive construction is common to most mining equipment, regardless of the target ore.

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I don't suffer from insanity. I enjoy it...

 

[itsmoked]

Boy, that falconbridge web site is well done. Nice sleuthing jraef!

Good luck pithpal!

Dress warmly..