Recently, three British inventors extract the carbon black from discarded tires. The carbon black, which has low price, may be used as a printing ink coloring of special carbon black substitutes.
The method can be generalized as the following: Isolated from the air, getting carbon black, steel and silica mixture after pyrolysising the in the condition of high temperature 800 ℃. Baking after magnetic separation and screening, the semi-pure charcoal powder is produced. And then washing it by using hydrochloric acid and sodium hydroxide, you can get the black printing ink with carbon black (also known as Acetylene black or lamp black). Compared with conventional furnace black production process, the pyrolysis process does not emit carbon dioxide.