System and method for preparing carbon black from waste tires by using pyrolysis

1 . A method of preparing carbon black, comprising:

performing a primary pyrolysis step of heating waste tires to produce first pyrolyzed substances comprising char and iron at a first pyrolysis unit;

transferring the first pyrolyzed substances from the first pyrolysis unit to a second pyrolysis unit;

performing a secondary pyrolysis step of heating the char and the iron of the first pyrolyzed substances to produce second pyrolyzed substances, at the second pyrolysis unit;

separating the char from the second pyrolyzed substances;

pulverizing the separated char through any one of a ring roller mill, an air classifier mill (ACM), or a raymond mill to a particle size of 80 μm or less;

pulverizing the separated char a second time through a ring roller mill or an ACM to a particle size of 10 μm or less to form carbon black;

pelletizing the carbon black, wherein in the pelletizing, a composition for pelletizing includes carbon black of 75 to 85 wt % and ash and inorganic additives of 15 to 25 wt %;

cooling and drying the pelletized carbon black; and

packaging the pelletized carbon black,

wherein a heating temperature of the secondary pyrolysis step is higher than a heating temperature of the primary pyrolysis step.

2 . The method of claim 1 , wherein in the primary pyrolysis step, the waste tires are heated to over 360° C., and in the secondary pyrolysis step, the char and iron are heated to over 650° C.

3 . The method of claim 2 , wherein the separating of the char from the second pyrolyzed substances comprises:

a primary sorting step; and

a secondary sorting step.

4 . The method of claim 3 , wherein in the primary sorting step, the char is vibrated to separate foreign substances from the second pyrolyzed substances, and in the secondary sorting step, the iron is separated from the char using magnetic force.

5 . The method of claim 1 , wherein the inorganic additive includes at least one of zinc oxide (ZnO), magnesium oxide (MgO), silica (SiO 2 ), zinc sulfide (ZnS), or calcium carbonate (CaCO 3 ).

6 . The method of claim 5 , wherein the pelletizing is performed by adding water and a cationic surfactant to the composition.

7 . A method of preparing carbon black, comprising:

performing a primary pyrolysis step of heating waste tires to produce first pyrolyzed substances comprising char and iron at a first pyrolysis unit;

recovering oil by condensing oil vapor generated in the primary pyrolysis, and reusing non-condensable gas that has not been condensed as a heat source for the primary pyrolysis;

transferring the first pyrolyzed substances from the first pyrolysis unit to a second pyrolysis unit;

performing a secondary pyrolysis step of heating the char and the iron of the first pyrolyzed substances to produce second pyrolyzed substances, at the second pyrolysis unit;

;

separating the char from the second pyrolyzed substances;

pulverizing the separated char through any one of a ring roller mill, an air classifier mill (ACM), or a raymond mill to a particle size of 80 μm or less;

pulverizing the separated char a second time through a ring roller mill or an ACM to a particle size of 10 μm or less to form carbon black;

pelletizing the carbon black, wherein in the pelletizing, a composition for pelletizing includes carbon black of 75 to 85 wt % and ash and inorganic additives of 15 to 25 wt %

cooling and drying the pelletized carbon black;

cooling and drying the pelletized carbon black; and

packaging the pelletized carbon black.

8 . The method of claim 7 , further comprising:

processing flue gas generated in the primary pyrolysis.

9 . The method of claim 8 , wherein the processing of the flue gas comprises:

a compression step of compressing the gas;

a denitrification step of removing nitrogen from the gas; and

a desulfurization step of removing sulfur from the gas.

10 . The method of claim 1 , wherein the non-condensable gas is transferred to and stored in a gas tank through transfer fan.

11 . The method of claim 10 , wherein the non-condensable gas stored in the gas tank is transferred to a hot air furnace of the primary pyrolysis and reused as a heat source for the primary pyrolysis.

12 . The method of claim 1 , wherein the first pyrolyzed substances includes at most 15 wt % gas and at least 40 wt % oil.

13 . The method claim 10 , wherein the water added may be 40 to 50 parts by weight based on 100 parts by weight of carbon black, and the amount of cationic surfactant added may be 0.1 to 1 part by weight based on 100 parts by weight of carbon black.