Question

(a) In smelting process carried out in blast furnace for the exgtraction of iron, lower region of the furnace has the highest temperature.
(b) Formation of $CO$ from ${CO}_2$ and coke reduces the temperature of the middle region of blase furnace.
(c) Limestone is taken blast furnace as flux.
(d) Silica present in the ore as gangue is converted to fusible slag by the process of reduction
Which of the following regarding the process of smelting is correct?

• A. a, b and c
• B. b and c
• C. only a
• D. only d

Answer 1

Answer: (A)

a, b and c

The extraction of metal in the fused state is termed smelting. The ore is reduced by carbon to the free metal. A hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes . Formation of $CO$ from $C{O}_2$ and coke reduces the temperature of the middle region of blase furnace. Flux is a chemical substance which combines with gangue at higher temperaturesto form easily fusible material called slag which is not soluble in the molten metal. Limestone is taken blast furnace as basic flux. Silica present in the ore as gangue is converted to fusible slag by the process of oxidation in flux.