Education Journalist | Study Abroad Lead
The metals form oxide ores through the electrolysis process. These ores convert carbonates and sulfides to oxide ores after turning them into metals. The conversion takes place through a calcination or roasting process. It is easy to reduce oxide ores. However, the ores heat in the absence of oxygen in the calcination process. The entire process becomes vain in the presence of air or oxygen. Oxide ore is reduced in the reduction process. Let’s have closer look at the calcination and roasting process and discuss some important questions.
| Table of Content |
Keyterms: Calcination, Roasting, Carbonates, sulfides, oxide, metals, oxygen, Zinc Sulphide, Zinc oxide
What is Calcination?
[Click Here for Sample Questions]
The conversion of ore into oxide through the heating process is calcination. In the absence of air, ore heats below the melting point. This procedure is used in converting carbonates and hydroxide to oxides. Moisture and volatile impurities are removed during the calcination process. It is described as a thermal process. Moreover, it helps to change solid materials by conducting a thermal decomposition. The reactions occur at the temperature of thermal decomposition. Calcining is a product of calcination. These are the compounds that pass thermal treatment.
Calcination
The word calcination derives from a Latin word. However, the decomposition of limestone to lime and carbon dioxide is aided by the calcination process.
CaCO3 —> CaO + CO2
Also Read:
| Chapter Related Articles | ||
|---|---|---|
| Ellingham Diagram | Precipitation Titration | Leaching Process |
| Zinc extraction metallurgy | Column Chromatography Principle | L methionine |
What is Roasting?
[Click Here for Sample Questions]
The conversion of ore into oxide by excess heating above melting point is Roasting. It is used for converting sulfide ores. During the process, impurities in the form of volatile gas are released. Sulfation, chlorination, oxidation, reduction, and pyro hydrolysis are among the solid-gas thermal reactions used in this approach. The vital source of air pollution is sulfides. It is a drawback for roasting due to the high amount of acid, toxic and metallic compounds.
Roasting
The conversion of Zinc Sulphide into zinc oxide is an example of roasting.
2ZnS + 3O2 —> 2ZnO + 2SO2
Difference between Calcination and Roasting
[Click Here for Sample Questions]
Roasting is used to oxidize the impurities. On the other hand, calcination removes volatile impurities.
The following table shows the difference between calcination and roasting.
| Calcination | Roasting |
|---|---|
| The heating process takes place in the presence of oxygen/air. | The heating process takes place in the absence of oxygen/air. |
| It involves the decomposition of carbonate ores. | The method forms sulfide ores. |
| Expel moisture from the ore. | Absence of dehydration of ore. |
| A metal oxide assists the production of carbon dioxide. | The metal oxide ensures the production of sulfur dioxide. |
Things to Remember
- The conversion of ore into oxide through the heating process is calcination. On the other hand, roasting converts ore into oxide by excess heating above the melting point.
- The decomposition of limestone to lime and carbon dioxide is provided by a calcination process. Furthermore, the conversion of Zinc Sulphide into zinc oxide is an example of roasting.
- The crucial difference is calcination takes place in the presence of oxygen/air and roasting in the absence of air/oxygen.
Also Read:
Sample Questions
Ques: Why do the sulfide ores ensure the roasting process, and carbonate ore is calcined? (2 marks)
Ans: In the roasting process, sulfide ore heats in the air and converts to metal oxide. But, in the case of carbonate ore, the moisture and carbonate are eliminated through the calcination process. Hence, roasting is inapplicable for carbonate ores. So, sulfide ores are roasted.
Ques: Define calcination. (2 marks)
Ans: The conversion of ore into oxide through the heating process is calcination. In the absence of air, ore heats below the melting point. This procedure is used in converting carbonates and hydroxide to oxides. Moisture and volatile impurities are removed during the calcination process.
Ques: What is calcining? (1 mark)
Ans: Calcining is a product of calcination. These are the compounds that pass thermal treatment. However, the ores heat in the absence of oxygen in the calcination process.
Ques: Write an example for the calcination process? (2 marks)
Ans: The word calcination derives from a Latin word. However, the decomposition of limestone to lime and carbon dioxide is aided by the calcination process.
CaCO3 —> CaO + CO2
Ques: Define the roasting process. (2 marks)
Ans: The conversion of ore into oxide by excess heating above melting point is Roasting. It is used for converting sulfide ores. During the process, impurities in the form of volatile gas are released.
Ques: Which thermal reactions exist in roasting? (2 marks)
Ans: Roasting is used to oxidize the impurities. Sulfation, chlorination, oxidation, reduction, and pyro hydrolysis are among the solid-gas thermal reactions used in this approach. The vital source of air pollution is sulfides.
Ques: Depict the production takes place in calcination and roasting. (2 marks)
Ans: A metal oxide assists the production of carbon dioxide in calcination. Furthermore, the metal oxide ensures the production of sulfur dioxide in roasting.
Ques: Write two differences between roasting and calcination. (2 marks)
Ans: The healing process occurs in the presence of oxygen/air in calcination and the absence of oxygen/air in the roasting process. In calcination, expel moisture from the ore and roasting forms absence of dehydration of ore.
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Check-Out:
Comments