Problem 12 - A Complete Resource Book in Chemistry for JEE Main

Question

Wolframite ore is separated from tinstone ore by the process of (a) smelting (b) calcination (c) roasting (d) electromagnetic

Step-by-Step Solution

Answer

(d) electromagnetic

Step 1: Understanding the Problem

We need to find out which process is used to separate wolframite ore from tinstone ore. This involves knowing what each process does and identifying the suitable method for separation.

Step 2: Analyzing Each Process

1. **Smelting**: This involves heating ores in the presence of a reducing agent to extract a base metal. It's not commonly used to separate wolframite from tinstone. 2. **Calcination**: This involves heating a substance in a controlled environment to remove volatile substances. It's also not typically used for separating ores. 3. **Roasting**: Heating of sulfide ores in air to convert them to oxides. This typically isn't used for wolframite separation. 4. **Electromagnetic separation**: Utilizes the magnetic properties of the substances involved. Wolframite is magnetic, whereas tinstone is not, making this process suitable for their separation.

Step 3: Choosing the Correct Process

Since wolframite is magnetic and tinstone is non-magnetic, electromagnetic separation is the most appropriate method to separate these ores efficiently.

Key Concepts

Electromagnetic Separation

Electromagnetic separation is a crucial technique in mineral processing, especially when it comes to separating magnetic materials from non-magnetic ones. This method exploits the magnetic properties of minerals to perform effective separation. When a mineral such as wolframite shows magnetic characteristics, it can be separated from non-magnetic minerals like tinstone. This is done by using electromagnetic separators that generate magnetic fields. The ore containing wolframite and tinstone is passed through such a separator. The magnetic force will attract the wolframite, allowing it to be collected separately from the non-magnetic tinstone.

Key Advantages of Electromagnetic Separation:

• High precision in segregating materials based on magnetism.
• Efficient for separating magnetic from non-magnetic ores.
• Simple setup and operation.

This method is especially preferred in mining industries where the goal is to purify and concentrate ores.

Wolframite

Wolframite is an important ore of tungsten, a metal with high commercial and industrial value. It is typically found in quartz veins and pegmatites. One of its distinguishing features is its magnetic properties, which play a critical role when it is separated from other minerals like tinstone through electromagnetic separation.

Characteristics of Wolframite:

• Heavy mineral with a notable gray or brown-black appearance.
• Contains high levels of tungsten (approximately 76% when pure).
• Magnetic properties make it ideal for magnetic separation techniques.

These properties ensure that wolframite remains a pivotal mineral in tungsten extraction, aiding industries such as aerospace, military, and electronics, where tungsten's heat resistance and high-density attributes are desired.

Tinstone

Tinstone, also known as cassiterite, is the primary ore of tin. It is widely used in the production of tin alloys such as bronze. Tinstone is non-magnetic, differentiating it significantly from wolframite, and this characteristic is a vital consideration in the process of electromagnetic separation.

Notable Features of Tinstone:

• High density and a generally brownish to black color with an adamantine luster.
• Primary ore for tin extraction, widely found in alluvial deposits.
• Tin from tinstone is used extensively in soldering, coatings, and conservation techniques.

The non-magnetic nature of tinstone means it remains unaffected by magnetic fields, allowing for straightforward separation from wolframite in mineral processing frameworks.

Mineral Processing

Mineral processing is the discipline of separating valuable minerals from their ores through various technologies, enhancing the value and purity of these materials. The goal is to increase concentration and reduce impurities, making materials suitable for industrial use. Fundamental techniques used in mineral processing include crushing, grinding, and separation methods like flotation, gravity, and electromagnetic separation.

In the context of wolframite and tinstone, electromagnetic separation showcases how specific properties of minerals can be effectively utilized. By strategically applying such techniques, industries optimize the yield of necessary materials while minimizing waste.

Core Principles of Mineral Processing:

• Understanding the properties of each mineral for optimized process design.
• Achieving high efficiency and purity in extracting valuable metals.
• Employing a range of techniques to maximize extraction rates and quality.

These processes ensure that industries can meet global material demands while maintaining sustainability and cost-effectiveness.