The function of potassium ethyl xanthate in froth floatation process is to make the ore
water repellant
lighter
heavier
attracted towards water
From the Ellingham graphs on carbon, which of the following statements is false?
CO reduces Fe2O3 to Fe at less than 983 K
CO is less stable than CO2 at more than 983 K
CO reduces Fe2O3 to Fe in the reduction zone of blast furnace
CO2 is more stable than CO at less than 983 K
The ore that is concentrated by the froth floatation process is
cryolite
cuprite
calamine
chalcopyrites
Copper is extracted from copper pyrites by heating in a Bessemer converter. The method is based on the principle that
copper has more affinity for oxygen than sulphur at high temperature
iron has less affinity for oxygen than sulphur at high temperature
copper has less affinity for oxygen than sulphur at high temperature
sulphur has less affinity for oxygen at high temperature
van-Arkel method of refining zirconium involves
removing all oxygen and nitrogen impurities
removing CO impurity
removing hydrogen impurity
removing silica impurity
Cryolite is
Na3AlF6 and is used in the electrolysis of alumina for decreasing electrical conductivity
Na3AlF6 and is used in the electrolysis of alumina for lowering the melting point of alumina only ·
Na3AlF6 and is used in the electrolysis of alumina for lowering the melting point and increasing the conductivity of alumina
Na3AlF6 and is used in the electrolytic refining of alumina
The metal extracted by leaching with a cyanide is
Al
Na
Cu
Ag
D.
Ag
Silver are forms a soluble complex with NaCN forms which silver is precipitated using scrap zinc.
(i) Ag2S + 2NaCN → Na[Ag(CN)2]Zn
(ii) Na2 [Zn(CN)4] + Ag↓
Spdium argentocyanide (soluble).
Which one of the following ores is best concentrated by froth-floatation method ?
Magnetite
Cassiterite
Galena
Malachite