Coke – Production, Processing & Environmental Hazardous waste

“Coke “ produced when pulverized soft coal is heated in the absence of oxygen. Carbon content present in Coke is 87 % to 89 % . Coke is dark gray , porous solid and burns with intense heat and very little smoke.

Used as a fuel in blast furnaces for the manufacturing of iron & steel .

The Processing of Coke (coking process) :

The process involves heating coal to about 2000-degree Fahrenheit for about 18 hours, in narrow , rectangular, silica brick ovens . Ovens stand in groups of 10 to 100 , called batteries.

Organic substances that make up coal volatize at this temperature, leaving the coke behind. The volatilized gas is then subjected sequentially lower temperature condensing chambers which capture tar , oils, light oils, then low-molecular weight gases. The separated coke is then used as fuel or as a component of steel. Some of the coke is used as fuel in the same coke ovens where it was produced.

Production of coke is one of the major processes in an integrated steel mill.

first compounds (highest condensing temperature) to be recovered are tars . Mostly coke plants recover several high-molecular-weight materials from several separate high-temperature condensers

vaporized organics produced in the ovens are withdrawn during cooking and sprayed with water . Sprayed water saturates and cools the gas , causing condensation of tar .

The mixture of flushing liquid and tar flows to a separator

Ammonia ( NH3 ) is recovered from Flushing liquid by semi direct or indirect methods .

Sources of Waste :

Coke production creates solid , Waterborne and airborne wastes . Phenolic compounds are also found in coke waste .

Solid Wastes :

In addiction to normal solid waste , include reject coal, reject coke, sludges from clarification of quench water, and normal packaging and shipping wastes.