Which of the following statement is not
true about'roasting?
Moisture is removed
Organic matter is oxidised and
removed
O
Makes the ore less porous
Metal sulphides are oxidised to
metal oxides
Answers
Organic matter is oxidised and removed.
Plss thank all my answers as i want reach my target of five thousand thanks plss whoever is watching this plss thank alllll my answers
Explanation:
Roasting:
Ores are heated to a high temperature below their melting point in the presence of excess air. The moisture escapes and impurities like sulphur, arsenic, phosphorous etc are oxidized to their volatile oxides. The mass becomes porous.
S+O
2
→SO
2
↑
4P+5O
2
→2P
2
O
5
↑
4As+3O
2
→2As
2
O
3
↑
Sulphide ores are converted into metal oxides.
2ZnS+3O
2
→2ZnO+2SO
2
↑
2Cu
2
S+3O
2
→2Cu
2
O+2SO
2
↑
Calcination:
The ore is heated to a high temperature below its melting point in the absence of air or in a limited supply of air. The organic matter, moisture, volatile impurities like carbon dioxide and sulphur dioxide are expelled from the ore. It makes the ore porous. For example, zinc carbonate decomposes to give zinc oxide and carbon dioxide.
ZnCO
3
Δ
ZnO+CO
2
So,plz mark me as brainliest answer.