The total chemical energy is the sum of heat input from natural gas, coal/carbon injection, electrode consumption, and other fuels. Each fuel contribution is calculated by multiplying mass flow rate by its heating value.

\begin{equation}\label{eq:eaf-chemical-energy-input} Q_\text{chem} = Q_\text{ng} + m_\text{coal} c_\text{coal} + m_\text{elec} c_\text{elec} + Q_\text{other}\end{equation}

Symbols

\(Q_\text{chem}\)	Total chemical energy input \([\unit{ \btu\per\hour}]\)
\(Q_\text{ng}\)	Natural gas heat input \([\unit{ \btu\per\hour}]\)
\(m_\text{coal}\)	Mass of coal/carbon injection \([\unit{ \pound\per\hour}]\)
\(c_\text{coal}\)	Heating value of coal/carbon \([\unit{ \btu\per\pound}]\)
\(m_\text{elec}\)	Electrode use \([\unit{ \pound\per\hour}]\)
\(c_\text{elec}\)	Electrode heating value \([\unit{ \btu\per\pound}]\)
\(Q_\text{other}\)	Other fuel heat input \([\unit{ \btu\per\hour}]\)