Question
Explain froth floatation process.###How will you concentrate sulphide ores?###Explain-the concentration of copper pyrites and galena ores.
✓
Answer
Froth flotation :
This method is commonly used to concentrate sulphide ores such as galena ( PbS $)$, zinc blende $( ZnS )$ etc. In this method, the metallic ore particles which are preferentially wetted by oil can be separated from gangue. In this method, the crushed ore is suspended in water and mixed with frothing agent such as pine oil, eucalyptus oil etc. A small quantity of sodium ethyl xanthate which acts as a collector is also added. A froth is generated by blowing air through this mixture.
The collector molecules attach to the ore particle and make them water repellent. As a result, ore particles, wetted by the oil, rise to the surface along with the froth. The froth is skimmed off and dried to recover the concentrated ore. The gangue particles that are preferentially wetted by water settle at the bottom.
When a sulphide ore of a metal of interest contains other metal sulphides as impurities, depressing agents such as sodium cyanide, sodium carbonate etc are used to selectively prevent other metal sulphides from coming to the froth. For example, when impurities such as ZnS is present in galena ( PbS $)$, sodium cyanide $( NaCN )$ is added to depresses the flotation property of ZnS by forming a layer of zinc complex $Na _2\left[ Zn ( CN )_4\right]$ on the surface of zinc sulphide.
This method is commonly used to concentrate sulphide ores such as galena ( PbS $)$, zinc blende $( ZnS )$ etc. In this method, the metallic ore particles which are preferentially wetted by oil can be separated from gangue. In this method, the crushed ore is suspended in water and mixed with frothing agent such as pine oil, eucalyptus oil etc. A small quantity of sodium ethyl xanthate which acts as a collector is also added. A froth is generated by blowing air through this mixture.
The collector molecules attach to the ore particle and make them water repellent. As a result, ore particles, wetted by the oil, rise to the surface along with the froth. The froth is skimmed off and dried to recover the concentrated ore. The gangue particles that are preferentially wetted by water settle at the bottom.
When a sulphide ore of a metal of interest contains other metal sulphides as impurities, depressing agents such as sodium cyanide, sodium carbonate etc are used to selectively prevent other metal sulphides from coming to the froth. For example, when impurities such as ZnS is present in galena ( PbS $)$, sodium cyanide $( NaCN )$ is added to depresses the flotation property of ZnS by forming a layer of zinc complex $Na _2\left[ Zn ( CN )_4\right]$ on the surface of zinc sulphide.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
$\left[ Fe \left( H _2 O \right)_6\right]^{3+}$ is strongly paramagnetic whereas $\left[ Fe ( CN )_6\right]^{3-}$ is weakly paramagnetic. Explain.
→Describe about the working principle of Leclanche cell.
Describe about lead storage battery construction and its uses.
An organic compound (A) of molecular formula $C _6 H _6 O$ gives violet colour with neutral $FeCl _3$. (A) on reaction with zinc dust gives (B) of formula $C _6 H _6$ (B) on treatment with acetvl chloride in the presence of anhydrous $AlCl _3$ gives ( C ) of formula $C _8 HO$. (C) on Clemmenson reduction gives (D) of formula $C _8 H _{10} O$. Identify $A , B , C , D$ and explain the reaction involved.
→Write down the possible isomers of the $C _4 H _9 NO _2$ give their IUPAC names.
→How would you determine the reduction potential of $Zn / Zn ^{2+}( aq )$ ? (or) How will you calculate the reduction potential of Half cell?
→Convert the following.
(i) Nitro benzene → Benzene
(ii) Benzene → Benzoic acid
(i) Nitro benzene → Benzene
(ii) Benzene → Benzoic acid
Starting from Benzene diazonium chloride, how would you prepare
(i) Benzene
(ii) Phenol
(iii) Nitro benzene
(iv) Benzolc acid
(v) Fluorobenzene
(i) Benzene
(ii) Phenol
(iii) Nitro benzene
(iv) Benzolc acid
(v) Fluorobenzene
Prove the buffer action of acetic acid and sodium acetate by the addition of 0.01 mol of solid sodium hydroxide.
Describe the following electrophilic substitution reaction using phenol.
- Nitrosation
- Nitration
- Sulphonation