25---Thursday---Stonedust---(Recognised Standard 5) ---25th January 2016 uploaded Flashcards
List the two different types samples?
Spot or strip
The limestone must be of such fineness. what percentage must pass through a sieve in the 1st instance? List the percentage and secondly list the size of the sieve that it must pass through?
Not less than 95% must pass through. A 250 micrometer sieve
Of the dry dust which passes through the 250 micrometer sieve. What percentage must pass through a sieve in the 2nd instance? List the percentage range and secondly list the size of the sieve that it must pass through?
Not less than 60% and not more than 80% by mass must pass through a 75 micrometer sieve
What are the properties of stonedust used for explosion suppression?
Light in colour and it must contain no more than 3% by mass of silica
How are strip samples taken?
Should be taken from a traverse strip around the periphery of the roadway of such width so as to contain a sample sufficient to test and it must be taken to a height around the roadway that is safely practicable
How are spot samples taken?
These should be taken from a series of spots each comprising an area of not less than 0.1 m2 of the roadway floor or sidewalls.
What is the maximum depth that a sample should be taken?
A depth not greater than 5 mm
What happens if the sample is wet and water can be squeezed from it?
The sample shall be discarded and a record kept of the sample location and fact that it was too wet.
How many zones should the mine generally be divided up in according to the percentage of incombustible dust?
85% zone,
80% zone,
70% zone.
How often are representative samples taken from the zones as per the regulations?
85% zone weekly,
80% zone Monthly,
70% zone 3 monthly.
An 85% zone is divided up into sub zones what are these sub zone lengths?
100m
Excluding 85% zones What are the lengths of all the other sub zones in the mine that are longer than 200m?
The sub zone is divided up into 200m lengths.
In an 80% Zone where ??? composite samples show compliance for ??? Months throughout a sequence of sub zones the length of the sub zones can be increased to ???
80% zone,
4 composite Samples,
4 months,
500M
In an 70% Zone where a conveyor is running where ??? composite samples show compliance for ??? Months throughout a sequence of sub zones the length of the sub zones can be increased to ???
70% zone,
4 composite Samples,
12 months,
500M
In OTHER the rest of the 70% Zone where ??? composite samples taken consecutively show compliance over ??? Consecutive Months throughout a sequence of sub zones the length of the sub zones can be increased to ???
70% zone,
2 composite Samples,
6 months,
1000M
What happens in the event that non compliance of any sub zone occurs more than once consecutively?
Sub zone reverts back to 200m
In zones requiring an incombustible content of 85 % samples of dust should be taken from ??? Samples points in the sub zone per roadway to make a composite sample. And seconly where should one of those samples be taken in the sub zone? How often and what type of samples are required to be taken?
10 samples,
From each open cut through adjacent to the heading in the zone,
weekly spot samples ( not in Standard 5)
In zones requiring an incombustible content of 80 % samples of dust should be taken from ??? Samples points in the sub zone per roadway to make a composite sample. And seconly where should one of those samples be taken in the sub zone? How often and what type of samples are required to be taken?
10 samples,
From each open cut through adjacent to the heading in the zone,
Monthly strip samples
In zones requiring an incombustible content of 70 % samples of dust should be taken from ??? Samples points in the sub zone per roadway to make a composite sample. And seconly where should one of those samples be taken in the sub zone? How often and what type of samples are required to be taken?
10 samples,
From each open cut through adjacent to the heading in the zone,
Three Monthly strip samples.
Name 3 ways in which dust samples are analysed?
Portable instrument method,
Laboritory Method,
Colorimetric
How often is a development district stone dusted?
Every 50 meters or 24 hours whichever comes first.
List the conditions where the content of incombustible dust at the mine is not kept to the requirements of the regulations?
Where there is a sufficient natural make of water associated with the mining operation to prevent a coal dust explosion.
What are the requirements for incombustible dust at 5 places in the mine as per the regulation 301?
For dust in a panel roadway within 200m Outbye of the last completed line of cut throughs in the panel 85%
For dust in a 200m section of a panel roadway within 400m of a longwall face 85%
For dust in a panel roadway within 200m from the main roadway if the above do not apply 80%
For dust in a return roadway if the above do not apply 80%
For dust in an intake roadway if the above do not apply 70%.
