Which one of the following options is correct?
Red mud is generated in the production of:
Red mud is generated in the production of:
Show Hint
- Aluminium
- Iron
- Titanium
- Copper
The Correct Option is A
Solution and Explanation
Aluminium metal is extracted from its ore bauxite in two broad stages: first, the Bayer process purifies bauxite into alumina (\(Al_2O_3\)), and then the Hall-Heroult process electrolytically reduces alumina to metallic aluminium. Red mud is a byproduct of the first stage, the Bayer process.
Step 2: Recall the Bayer process itself.
In the Bayer process, crushed bauxite ore is digested in hot, concentrated sodium hydroxide (\(NaOH\)) solution under pressure. The aluminium-bearing minerals in the ore dissolve as sodium aluminate, while the impurities in the ore, mainly iron oxides, silica, titanium oxide, and other insoluble solids, do not dissolve and are filtered off as a solid residue.
Step 3: Identify red mud.
This insoluble residue is called red mud, and it gets its reddish-brown colour mainly from the iron oxide content left behind from the original bauxite ore. Red mud is produced in very large volumes (typically one to two tonnes of red mud per tonne of alumina produced) and is a well known environmental disposal challenge for the aluminium industry.
Step 4: Rule out the other metals.
(B) Iron: Iron is extracted from iron ore (hematite/magnetite) in a blast furnace, producing slag as its main waste, not red mud. Incorrect.
(C) Titanium: Titanium is extracted mainly from ilmenite or rutile by the Kroll process, which produces magnesium chloride as a byproduct, not red mud. Incorrect.
(D) Copper: Copper is extracted from sulfide ores mainly by smelting, producing slag and sulfur dioxide gas, not red mud. Incorrect.
Step 5: Final conclusion.
Red mud is specifically the insoluble bauxite residue from the Bayer process used to make alumina on the way to metallic aluminium.
\[ \boxed{\text{Aluminium}} \]
Top GATE MT Mineral Processing and Extractive Metallurgy Questions
Match each crystal defect in Column I with the corresponding type in Column II.
- Consider the following gas-phase reaction: \[ 2 {SO}_2 + {O}_2 \rightleftharpoons 2 {SO}_3 \] If the enthalpy of reaction is negative, which one of the following conditions promotes a higher equilibrium concentration of SO\(_3\)?
- In the Fe-C system, the invariant reaction Liquid + $\delta$ $\rightleftharpoons$ $\gamma$ takes place at 1493 °C. This type of reaction is called ______.
Consider the gas phase reaction: \[ CO + \frac{1}{2} O_2 \rightleftharpoons CO_2 \] At equilibrium for a particular temperature, the partial pressures of \( CO \), \( O_2 \), and \( CO_2 \) are found to be \( 10^{-6} \, {atm} \), \( 10^{-6} \, {atm} \), and \( 16 \, {atm} \), respectively. The equilibrium constant for the reaction is ......... \( \times 10^{10} \) (rounded off to one decimal place).
Match the phenomena in Column I with the typical observations in Column II.
Top GATE MT Aluminium Extraction Questions
Top GATE MT Questions
Despite his initial hesitation, Rehman’s ____________ to contribute to the success of the project never wavered.
Select the most appropriate option to complete the above sentence.Bird : Nest :: Bee : __________
Select the correct option to complete the analogy.- If \( P e^x = Q e^{-x} \) for all real values of \( x \), which one of the following statements is true?
The paper as shown in the figure is folded to make a cube where each square corresponds to a particular face of the cube. Which one of the following options correctly represents the cube? Note: The figures shown are representative.
- Let \( p_1 \) and \( p_2 \) denote two arbitrary prime numbers. Which one of the following statements is correct for all values of \( p_1 \) and \( p_2 \)?