Disadvantages Of Calcination

• i. aeration

• ii. Calcination

• iii. Roasting

• iv. Agglomeration

Pretreatment method

• aeration aeration generally means the elimination of mechanically held water or damp from deliberate, or other solid materials by evaporation, i.e. expensive operation, frequently completed in a aeration furnace (fixed or fluidized bed, or kiln) Calcination

• Calcination is the thermal management of an ore or a ponder to effect its breakdown and the elimination of a explosive product, regularly CO2, water vapor, or other gases.

• consequently, by distinguish with aeration, calcination involves the removal of H2O,

CO2, etc., which are chemically jump as e.g. hydrates or carbonates.

Temperature important for the breakdown pressure to reach 1 atm

vary,

Agglomeration

When the element size of an ore or deliberate is else small for use in a later stage of conduct, i.e. in the blast furnace, it must be reformed into lumps of suitable size and strength that is agglomerated.

Extraction by means of Flotation:

• Froth flotation - a method where precious minerals are separated from tailing by suggest them to group on the floor of a froth layer.

– This process is based on the capability of definite chemicals to adapt the surface properties of the minerals. – further chemicals are use to generate the froth and still others are used to alter the pH.

• The progression of froth flotation involves crushing and grinding the ore to a well size

– This separates the individual mineral particles from the squander rock and other mineral particles.

– The grinding is generally done in water with the follow-on slurry called the pulp.

• The pulp is processed in the flotation cells.

– Here the pulp is squirmy with a flotation mixture

– Fine froth are introduced

• The capability of a mineral to float depends upon its surface properties.

– Chemical variation of these properties enables the mineral particles to attach to an

– The air babble and mineral particles rise through the pulp to the surface of the froth.

• still though the air bubbles habitually break at this point, the mineral leftovers on the surface of the froth.

• The mineral is physically separated from the permanent pulp material and is removed for extra dispensation.

Sulphide Minerals

• Are occasionally roasted

– Heated in air with no melting to alter sulphides to oxides

– Gives inedible H2S and SO2

– Then oxides processed alike to Fe

• evolution of roasting and smelting together makes a lusterless – Sulfides are melted into a lusterless and air is goes through. S is distorted to sulfur dioxide and Fe to iron oxide, and Cu and Ni continue in melt

• Solvent extraction/electroplating

– worn where rock contains Cu but in too slight amounts to be recovered by standard methods

Heap Leaching

Here in this process, generally done for Au, the ore is not floor, but quite, trodden and piled on the outside.

• frail solutions of NaCN (0.05%) penetrate through the material discharge out the

favored