Question

Assertion- In the froth floatation method, collectors such as pine oil xanthates are added to the suspension of powdered ore.
Reason-Collectors stabilize the froth.
(A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(C) Assertion is correct but Reason is incorrect
(D) Both Assertion and Reason are incorrect

Answer 1

Hint: As we know that froth flotation is a technique or method for selectively separating hydrophobic materials from a hydrophilic substance. This process is especially used in mineral processing, paper recycling as well as in waste water treatment industries so as to use pure water in the next cycle.

Complete answer:
Let us discuss about froth floatation method as follows:-
-Froth floatation method: It is one of the most popular operational techniques used for mineral beneficiation or extraction. It is a method through which economically and commercially important minerals are separated from impurities by collecting them just on the surface of a froth layer. Generally sulphide ores containing multiple metals such as lead, copper and zinc can be separately extracted by using this process.
-The basic principle used is the difference in the wetting ability of the ore, important metals and other impurities as based on this we can separate hydrophobic materials from a hydrophilic substance.
-To maintain uniform quality of froth as well as optimize the adhesive quality of the minerals, various chemicals are required to be mixed in the slurry which are given below:-
Collector: These are the chemicals that enhance the non-wettability of the mineral particles. Some examples of collectors are pine oils, fatty acids, xanthates, etc.
Frother: These are also known as froth stabilizers as these are used to stabilize the froth during froth floatation method. Few frothers used in this process are cresols, aniline, etc.
Activator: These are the chemical reagents which activate the mineral surface towards the action of the collectors and this is achieved by enhancing their chemical properties.
Depressant: These are also known as deactivators as they used to deactivate the mineral surface towards the action of collectors and this is achieved through changes in their chemical properties.

From the above data it is clear that in the froth floatation method, collectors are added to the suspension of powdered ore which means the assertion is completely true but collectors do not stabilize froth. So the correct option is: (C) Assertion is correct but Reason is incorrect.

Note:
-Hydrophobic substances are those which do not attract water molecules due to which they are not miscible in water whereas hydrophilic .
-Also learn and understand various metallurgical processes used in the extraction of important metals and minerals.