hi guys........plzz explain me froth flotation in brief❤❤❤❤❤
Answers
Froth Floatation Process
Principle:
The principle of froth floatation is that sulphide ores are preferentially wetted by pine oil, whereas the gangue particles are wetted by water.
Collectors are added to enhance the non-wettability of the mineral particles. Examples of collectors are pine oil, fatty acids and xanthates. Froth stabilisers are added to stabilise the froth. Examples of froth stabilisers are cresols, aniline. If two sulphide ores are present, then it is possible to separate the two sulphide ores by adjusting the proportion of oil to water or by adding depressants. Example: For an ore containing ZnS and PbS, the depressant used is NaCN. It selectively prevents ZnS from coming to froth but allows PbS to come with the froth.
Method:
This method employs a mixture of water and pine oil which is made to froth in a tank to separate sulphide ores. The differences in the wetting properties of the ore and gangue particles separate them.
A mixture of water, pine oil, detergent and powdered ore is first taken in a tank. A blast of compressed air is blown through the pipe of a rotating agitator to produce froth. The sulphide ore particles are wetted and coated by pine oil and rise up along with the froth (froth being lighter). The gangue particles wetted by water sink to the bottom of the tank (water being heavier). Sulphide being more electronegative attracts the covalent oil molecules. The gangue being less electronegative is attracted by the water. The froth containing the sulphide ore is transferred to another container, washed, and dried.
Hi Angel Singh! Here's your answer :-
Froth flotation is one of the most popular operational processes for mineral beneficiation. In ore/mineral beneficiation, froth flotation is a method by which commercially important minerals are separated from impurities and other minerals by collecting them on the surface of a froth layer.
Flotation is the process of separation of beneficial minerals from a mixture by creating froth on which minerals separate out. This method of froth floatation is a method of mineral processing in which different minerals are separated selectively. Such ores containing multiple metals such as lead, copper and zinc can be selectively extracted by using froth floatation.
The method of froth floatation can be classified into three steps:
1. True floatation – In this process minerals are selectively attached to froth. This process is very critical and important as the extraction of the valuable minerals is decided by this step only while the other two steps determine the separation efficiency between the mineral and the gangue.
2. Entrainment – Under this process of entrainment air bubbles are passed in liquid water which the froth leads to the generation of air bubbles.
3. Aggregation – In this process, the mineral particles are trapped by the froth.
An important criterion of separation of minerals by the froth floatation method is that the size of the particles of the ores must be very small equivalent to powder form. This is very important because the heavier and bigger particle would require a greater adhesive force without which they would no longer attach to the froth and settle down in the bottom. Thus separation will not be possible.
Froth flotation is mainly operated under two common techniques :
1. Direct floatation technique – In this method the mineral sticks to the air bubble and the remaining gangue settles down at the bottom.
2. Reverse floatation technique – In this method, the gangue sticks to the air bubble and ore particle settle down in the bottom