Iron (obtained from its ore by smelting)?

Question

you know, the process extracting iron from iron ore using haematite, coke and limestone. They are put into the top of the blast furnace and hot air is blown in at the bottom.

The question is..

The waste gases leaving the furnace are mainly...
A.. Carbon dioxide and nitrogen
B.. Carbon dioxide and oxygen
C.. Carbon monoxide and Carbon dioxide
D.. Carbon monoxide and nitrogen

In the book, it says the answer is A.
I think the answer is B. is the answer in the book correct. why?

Answer 1

I would say A and C together

If I remember right CO & CO2 are produced by reacting in the smelting process and the Nitrogen just passes through without reacting.

All the pure oxygen gets burnt off due to the heat of the furnace

If I had to pick just one though I would pick A ... much of the CO reacts with limestone that is added during the process to produce more CO2

Answer 2

A ) is correct but the gas mixture will also contain enough carbon monoxide so that it produces more heat in the Cowper stoves.The answer B) can't be right because the object of the exercise is to remove oxygen from the iron oxide and tie it up with the reducing agent which is carbon.
Nitrogen forms 80% of the atmosphere so it must be the largest volume fraction of the out put gases.It wastes a lot of heat from the furnace.

Answer 3

The question is which are the MAIN gases leaving the furnace.

Air's oxygen is used to burn coke and produce carbon oxides, while nitrogen doesn't react. Since there is more nitrogen than oxygen in air, we know for a fact that there will be more nitrogen than the carbon oxides formed.

Also, although carbon monoxide might be a furnace gas, most of it reacts with the mineral to reduce it (it is a quick thermodinamically favored reaction), forming carbon dioxide.

So A is the right answer.

Answer 4

Well, it depends on the specifics of the process, and what type of iron ore is used.

Nitrogen is the primary component of the waste gasses, but it doesn't participate in the smelting process at all, and is just incidental. Apart from that, in order of abundance, is carbon dioxide, carbon monoxide, water vapor, sulfur dioxide(depending on the sulfur content of the ore), and miscellaneous gasses....

so the answer is (A), I suppose......

Although much carbon monoxide is produced initially, most of it reacts to reduce the iron ore, and also reacts with the limestone flux to produce CO2....

Some smelting operations use pure oxygen instead of air. This speeds up the process, increases the temperature, and increases the quality of the resulting raw pig iron.

~W.O.M.B.A.T.

Answer 5

Oxygen is pumped into the furnace to remove the carbon impurity.

C + 1/2 O2 --> CO
and
C + O2 --> CO2

Oxygen exists in other forms within the furnace also, as can be seen with the production of CaSiO3 using lime to remove the silicon impurities. Perhaps thats where the confusion arose.
Most oxygen already present within the furnace is likely to do the same thing.
Nitrogen being nitrogen, it's everywhere and there is lots of it.

Answer 6

No it is C coz because of reduction reactions taking place. The coke contains carbon and the oxygen oxidises the carbon to carbon dioxide. The carbon dioxide is also oxidised to make carbon monoxide so it is C. I no because I did Chemistry GCSE recently

Answer 7

Nitrogen from the hot air blown into the furnace.
Carbon dioxide from thye coke:

C + O2 ------> CO2

[C + CO2 -----> 2CO]

3CO + Fe2O3 --------> 2Fe + 3CO2

Oh I forgot, the answer is A

Answer 8

A is correct. The oxygen in the air is used in the combustion process, but the nitrogen is not.

Answer 9

Air is 79% Nitrogen and N2 is inert. So about 79% N2 will leave

Answer 10

Exothermic because heat is being released