Which form of the iron is the purest form of commercial iron ?

Wrought iron or malleable iron is the purest form of commercial iron and is prepared from cast iron by oxidising impurities in a reverberatory furnace lined with haematite.

How copper is extracted from low grade ore?

Copper is extracted by hydro metallurgy from low-grade ore. Copper is extracted by leaching it with acid when copper metal goes into solution as Cu 2 + ions. The solution containing Cu 2 + ions is then treated with scrap iron or H 2 gas. In Reduction, this solution containing copper is treated with scrap iron or H 2 to get the copper. Cu 2 + ( aq ) + Fe → Cu ( s ) + Fe 2 + ( aq ) Cu 2 + ( aq ) + H 2 ( g ) → Cu ( s ) + 2 H + ( aq ) .

Give the Mond Process for refining of nickel.

Mond process for refining of nickel is based on the principle that nickel is heated in a stream of carbon monoxide forming a volatile complex (nickel tetracarbonyl). Ni + 4 CO → 330 - 350 K Ni ( CO ) 4 . The carbonyl is subjected to high temperature so that the complex decomposes to give the pure metal. Ni ( CO ) 4 → 450 - 470 K Ni + 4 CO . This process is called the Mond process.

What are roasting and calcinations? Explain with a chemical equation of each.

Roasting is defined as the process in which sulphide ore is heated in the presence of oxygen to convert into oxide. Example: 2 ZnS + 3 O 2 → 2 ZnO + 2 SO 2 Calcinations: It is defined as the process in which carbonate ore is heated in the absence of air to form oxide. Example: ZnCO 3 s → heat ZnO s + CO 2 g .

What are “minerals” and “ores” ? Differentiate between them.

Minerals: It is defined as the natural materials in which the metals or their compounds are found in the earth. Ores: It is defined as the minerals from which the metals can be extracted conveniently and profitably. The difference between them is given below: Minerals Ores These are native forms in which metals exist. These are mineral deposits.

Write short notes on : Froth floatation process

Froth floatation method: It is based on the principle of difference in the wetting properties of the ore and gangue particles with water and oil. Froth floatation technique is used for the concentration of sulphide ores such as zinc sulphide, lead sulphide etc.

Write short notes on : Zone refining

Zone Refining : It is also known as fractional crystallization method. In order to obtain metals of high purity for specific applications, this method is generally employed. Silicon and germanium used as semiconductors are obtained by this process. It is based on the principle that the impurity has greater solubility with the liquid than in solid state of the metal.

Explain the role of the following in the processes mentioned : Limestone in the metallurgy of iron.

For extracting iron, smelting is carried out in a blast furnace. The inside of the furnace is lined with very high melting refractory bricks. The calcined and roasted ore along with limestone CaCO 3 and coke (C) (ore 8 parts, limestone 1 part and coke 4 parts) are lifted to the top of the furnace and released at the mouth of the furnace provided with a cup and cone arrangement. Molten iron, thus formed is collected at the bottom of the furnace. Lime stone acts as a flux and removes siliceous impurities in the form of slag. CaCO 3 → ∆ CaO + CO 2 CaO + SiO 2 → CaSiO 3 ( Slag )

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Name one important ore of aluminium. Give its chemical composition.

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