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SUBJECT-CHEMISTRY


                                         CHAPTER-ISOLATION OF ELEMENTS.


                       SUBTOPIC- Ore, mineral,Concentration of ore,calcination and roasting.

               KEY NOTES:


                    Ores: The minerals from which the metal is economically and profitably extracted are
                     known as ores.
                    Sintering: It is a process of  crushing ore to reasonable size before concentration of ore.
                    Concentration of Ores: The process of removal of unwanted materials like sand, clay,
                     rocks etc from ore is known as concentration. It involves several steps.
                     (a) Hydraulic washing: It is based on difference in densities of ore and the gangue.
                     (b) Magnetic  separation:  This  method  is  based  on  magnetic  and  non  magnetic
                        properties of two components of ore.
                     (c)  Forth floatation method: This method is used for concentration of sulphide ores.
                     (d) Leaching : It is a process in which ore is treated with suitable reagent which dissolves
                        ore but not the impurity.
                    Calcination: It is a process of heating ore in absence of air so as to convert carbonate
                     ores into oxides.
                    Roasting:  It  is  the  process  in  which  ore  is  heated  in  regular  supply  of  air  at  a
                     temperature below melting point of metal so as to convert the given ore into oxide ore.
                    Flux:  The  chemical  substance  which  is  used  to  remove  infusible  impurity  in  smeting
                     process in know as flux.
                    Slag: The compound formed on reaction of gangue with flux is called slag.
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