The method is based on the two opposite properties, hydrophilic and
hydrophobic of the particles. Here the particles of the metal due to their
hydrophobic property get wetted mainly with oil while due to hydrophilic
property the gangue particles get wetted with water, by using these
properties certain ores are concentrated.
(ii) Draw a neat labelled diagram of above method.
Answers
Answer:
Hydroelectricity Verdict
The production capacity of a dam is dependent on the water supply available. Once constructed, a hydropower plant will be operational for decades and provided its water sources don’t run out, it can produce electricity at a constant rate. As mentioned earlier, the output can be easily controlled. The reservoir that forms behind the dam can be used for irrigation or for leisure purposes. Also, once the construction is completed, there is a negligible amount of greenhouse gas emission.
Dams also have a couple of problems, though. Dams are very expensive to build and to last decades, they must be built to a high standard. Also in the case of dam breaches, the runaway water will cause significant flooding in the downstream regions. Also, the creation of a reservoir causes a massive tract of land to get submerged. This area is lost and people living in such areas are displaced. Sometimes they are compensated, sometimes not. This creates a lot of tension between the construction and the affected people. Also, the construction of a dam blocks the natural flow of water and severely reduces the flow downstream. Such situations can cause disputes between neighboring countries and even neighboring states such as Karnataka and Tamil Nadu
OR
Correct option is
D
ZnS
Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. it is mainly used for treatment of sulphide ores.
In some cases for example, sulphides ores of copper, zinc and lead concentration is brought by this method. In this method advantage is taken of the referential wetting of the ore by an oil. The finely ground ore is taken in a tank containing water and 1% of pine oil or terpentine oil.
A strong current of air is blown through the suspension, producing a heavy froth or foam on the surface.The metal sulphide is wetted by the oil but the gangues is not and the sulphide-oil mixture is carried to the surface by films of oil. The froth is skimmed off, the gangue settles down on the bottom or remains underneath the froth. Hence, it is applicable for ZnS.