8 Most VSAQ’s of General Principles of Metallurgy Chapter in Inter 2nd Year Chemistry (TS/AP)

2 Marks

VSAQ-1 : Write any one ore with formulate of the following (i) Aluminium (ii) Zinc (iii) Iron (iv) Copper

  1. Aluminium
    • Ore: Bauxite
    • Formula: Al2O3·2H2O
  2. Zinc
    • Ore: Zincblende
    • Formula: ZnS
  3. Iron
    • Ore: Haematite
    • Formula: Fe2O3
  4. Copper
    • Ore: Copper pyrites
    • Formula: CuFeS2

VSAQ-2 : Explain ‘poling’.

Poling is a metallurgical process used in the refining of impure metals, such as copper. It involves heating the impure metal until it is molten and then introducing oxygen by thrusting a wooden pole into the molten metal. The oxygen reacts with impurities like sulfur to form slag, which is skimmed off, resulting in purified metal. It is a crucial step in improving the quality of metals.

VSAQ-3 : What is the role of cryolite in the metallurgy of aluminium?

Cryolite plays a pivotal role in the metallurgy of aluminum. It serves as a flux, lowering the melting point of the bauxite ore-aluminum oxide mixture, making the extraction process energy-efficient. Additionally, it acts as an effective electrolytic medium, enabling the reduction of aluminum ions to form aluminum metal during the Hall-Héroult process.

VSAQ-4 : Give the composition of the following alloys. a) Brass b) German silver c) Bronze

  1. Brass:
    • Brass is primarily composed of copper (Cu) and zinc (Zn) in varying proportions.
    • Common ratios include 70% Cu and 30% Zn for alpha brass and 90% Cu and 10% Zn for alpha-beta brass. Small amounts of other elements like lead (Pb) or tin (Sn) may be added for specific properties.
  2. German Silver (Nickel Silver):
    • German silver is mainly composed of copper (Cu), nickel (Ni), and zinc (Zn).
    • A typical composition is approximately 60% Cu, 20% Ni, and 20% Zn, although small amounts of iron (Fe) or manganese (Mn) may be included for certain characteristics.
  3. Bronze:
    • Bronze consists primarily of copper (Cu) and tin (Sn).
    • Common compositions include around 90% Cu and 10% Sn for traditional bronze. Elements like aluminum (Al), silicon (Si), or phosphorus (P) may also be added in varying amounts for specific bronze types.

VSAQ-5 : State the role of silica in the metallurgy of copper.

Silica (SiO2) in the metallurgy of copper acts as a flux. Its role is to lower the melting point of copper ore concentrates during smelting. This allows impurities to combine with silica to form slag, which can be easily separated from the molten copper, ensuring the purification of the final copper product.

VSAQ-6 : What is matte? Give its composition.

Matte in metallurgy is a sulfide-rich mixture formed during the smelting of sulfide ores. Its composition typically includes metal sulfides such as copper sulfide (Cu₂S), nickel sulfide (NiS), and iron sulfide (FeS), along with iron (Fe) and other impurities depending on the ore source. Mattemostly consists of these components and serves as an intermediate product in the extraction of metals from sulfide ores.

VSAQ-7 : What is blister copper? Why is it so called?

Blister copper is an intermediate product in copper metallurgy, named for the characteristic gas bubbles or “blisters” it contains. It forms during the smelting of copper sulfide minerals when sulfur dioxide gas (SO2) is produced, and these gas bubbles get trapped in the molten copper, giving it its distinctive appearance. Blister copper is further refined to remove impurities and gases, ultimately yielding pure copper metal.

VSAQ-8 : What is the difference between a mineral and an ore?

  1. Mineral: A mineral is a naturally occurring, inorganic solid substance with a specific chemical composition and a crystalline atomic structure.
  2. Ore: Ore is a type of mineral or a group of minerals that contains a valuable substance or metal in concentrations high enough to be economically extracted or mined. In other words, ores are minerals with economic significance.