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| Applications of Colloids |
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| Colloids have uses in our daily life as well as in various industrial processes. Some of the applications where colloids are present are listed below. |
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| 1) Pharmaceutical industry makes use of colloidal solution preparation in many medicines. A wide variety of medicines are emulsions. An example is Cod Liver Oil. |
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| 2) Paint industry also uses colloids in the preparation of paints. |
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| 3) Asphalt emulsified in water is used for building roads. |
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| 4) In metallurgical operations the metal ores are concentrated by froth-flotation process which involves the treatment of the pulverized ore in emulsion of pine oil. |
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| 5) The negatively charged rubber particles from rubber sol are deposited on wares and handles of different tools. Rubber gloves are formed by rubber plating on a suitable templates. |
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| Presence of colloids in certain cases causes problems especially, related to health of human beings and other creatures untreated sewage and smoke are harmful to health. Removal of the colloidal particles in these cases is essential. In sewage disposal, the colloidal particles are removed by discharging them at the electrodes. Sewage water is passed through a tunnel fitted with metallic electrodes, which are maintained at high potential difference. The particles move to the oppositely charged electrodes and coagulated. The coagulated matter is used as manure and the cleaned water is used for irrigation. |
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| Smoke is a dispersion of negatively charged colloidal particles of carbon in air. To remove the carbon in air, smoke is passed through a Cottrell Smoke Precipitator. |
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| fig.7.17 - Schematic diagram of Cottrell smoke precipitator |
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| The precipitator consists of two metal discs charged to a high potential. The charge on the unburnt carbon gets discharged. Consequently, the carbon particles aggregate and precipitates to the bottom. Cottrell smoke precipitator is usually used in the chimney of an industrial plant. |
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