This set of Iron Making Multiple Choice Questions & Answers (MCQs) focuses on “Petrographic and Other Characteristics of Coal – Set 2”.
1. Macerals are the microscopically identifiable ________
a) Single organic constituents
b) Grouped organic constituents
c) Single in-organic constituents
d) Grouped in-organic constituents
View Answer
Explanation: Macerals are the microscopically identifiable single organic constituents of a coal. Their reflectance and morphology are used to distinguish them under a microscope. Composition and properties of macerals may differ significantly from one coal to another.
2. Which are the main maceral groups?
a) Vitrinite, exinite and inertinite
b) Vitrinite and exinite
c) Exinite and inertinite
d) Vitrinite and inertinite
View Answer
Explanation: Vitrinite is a reactive maceral and burns readily during combustion. Exinite is the most reactive maceral group as it contains more hydrogen than the others. Inertinite is generally not reactive at all.
3. Mineral matter comprises of the ____________
a) Inorganic components of coal
b) Organic components of coal
c) Metallic components of coal
d) Non-metallic components of coal
View Answer
Explanation: Mineral matter comprises of the inorganic components of coal. During combustion of coal, the mineral matter composition gets changed due to evolution of the water of hydration and the release of components such as CO2 and SO2.
4. Which microscope is used to measure the reflectance of vitrinite?
a) Special reflectance microscope
b) Special transmission microscope
c) Special refractance microscope
d) Special total internal reflectance microscope
View Answer
Explanation: Reflectance is measured by microscopic examination of vitrinite using a special reflectance microscope. For performing reflectance microscopy the fine coal is made into a small sample using an adhesive and the top face of the sample is polished.
5. The extent by which light gets reflected from the surface is a measure of the ____________
a) Rank of the coal
b) Hardness of the coal
c) Strength of the coal
d) Brittleness of the coal
View Answer
Explanation: When light enters the polished surface, the extent by which light gets reflected from the surface is a measure of the rank of the coal. 100 such readings are usually reported and an average is taken.
6. Vitrinite is bireflective.
a) True
b) False
View Answer
Explanation: Vitrinite is bireflective because its reflectance varies as the microscope stage is rotated. Two maximas of reflectance are observed in one complete rotation (360°) give the maximum reflectance of the particular coal particle.
7. The mean maximum reflectance (MMR) is the mean of the reflectance of 100 separate vitrinite particles.
a) True
b) False
View Answer
Explanation: The mean maximum reflectance (MMR) is the mean of the reflectance of 100 separate vitrinite particles. The reflectance varies with the rotation of the microscope stage as vitrinite is bireflective.
8. What happens to the reflectance as the rank of the coal improves?
a) Increases
b) Decreases
c) Remains same
d) First increases then decreases
View Answer
Explanation: Vitrinite reflectance increases with the rank of coal. Among all influencing factors (rank, rotation, etc) rank is the most significant parameter influencing the coke making potential of the coking coal.
Sanfoundry Global Education & Learning Series – Iron Making.
To practice all areas of Iron Making, here is complete set of 1000+ Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
