04---Thursday---Damps

Question 1

What is firedamp?

Answer 1

Flammable gas formed by decomposition or distillation of coal

Question 2

What are Damps?

Answer 2

Terms for gaseous products formed in coal mines as distinguished from pure air

Question 3

Blackdamp refers to which 2 main gases?

Answer 3

Carbon Dioxide and Nitrogen

Question 4

What name is given to an atmosphere that causes choking or suffication due to insufficient oxygen ie large emmisions of gas maybe CO2 or Methane displacing the air?

Answer 4

Chokedamp

Question 5

What is the general composition of blackdamp?

Answer 5

85 to 90% N2 and 10 to 15% CO2

Question 6

How is blackdamp detected?

Answer 6

It extinguishes the flame on a oil lamp, In some cases it can be felt on the legs due to its heavy density and the hot effect which is due to the low thermal conductivity or with an oxygen meter

Question 7

Illawarra bottom gas will be heavier when it contains what gas, at what percent?

Answer 7

46% carbon Dioxide Then it will migrate this mix of gas of Methane and Carbon dioxide to the floor

Question 8

Afterdamp is composed of what gases?

Answer 8

CO, N2, CO2, and very little Oxygen and water vapour

Question 9

What makes afterdamp dangerous?

Answer 9

After an explosion the atmosphere is very humid and irrespirable containing toxic Carbon Monoxide and very little oxygen

Question 10

Whitedamp contains what main gas?

Answer 10

Carbon monoxide generally caused by coal mine explosions mine fires water gas and producer gas.

Question 11

Stinkdamp is which gas?

Answer 11

Hydrogen sulphide

Question 12

fire stink is the name for what?

Answer 12

It is the term applied to benzene associated odour that indicates spontaneous combustion

Question 13

Producer gas is what gases and percentages

Answer 13

CO 15%, CO2 10% N2 74% other gasses 1 %

Question 14

How is producer gas formed?

Answer 14

Commercially passing air through incandescent fuel (coal coke or charcoal)

Question 15

What are aldehydes?

Answer 15

Oxidised Hydrocarbons with the formula R_CHO

Question 16

How is water gas produced?

Answer 16

By passing steam over red hot coke the reaction is strongly endothermic. (requires heat). To maintain the required temp of 1200 to 1400 centigrade, it is necessary to stop every few minutes and allow air to enter the process

Question 17

What is the composition of water gas?

Answer 17

45% each CO, H2 Flammable limits are 6 to 9% and 70% by volume