Question

(i) Name of the method of refining which is based on the principle of adsorption.
(ii) What is the role of depressant in froth floatation process?
(iii) What is the role of limestone in the extraction of iron from its oxides?

Answer 1

(i) Chromatographic method is based on the principle of adsorption.
(ii) In froth floatation process, the role of depressants is to separate the two sulphide ores by adjusting proportion of oil to water.
(iii) In extraction of iron from its oxides, limestone is decomposed to $CaO$ which removes silicate impurity of the ore as slag. The slag is in molten state and separates out from iron.