Hot Charging

Charging slabs at an elevated temperature into the reheating furnace of the hot rolling mill will save energy. In addition hot charging improves material quality, reduces material losses, enhances productivity (by up to 6%), and may reduce slab stocking.

The layout of the plant will affect the feasibility of hot charging because the caster and reheating furnace should be located in proximity to one another to avoid a long, hot connection between the two.

Development Status Products
Rolled steel

Hot ChargingCosts & Benefits

Parent Process: Rolling Mills
Energy Savings Potential

Energy savings of 0.06 GJ/t-rolled steel are estimated (US EPA, 2010. p.27). 

Japanese flag In a Japanese plant, hot charging has reduced specific fuel consumption in the heating furnace by 0.21 GJ/t-product (NEDO, 2008. p. 86)

CO2 Emission Reduction Potential

Emissions reduction potential is estimated to be 30.2 Kg CO2/t-rolled steel. 


Retrofit capital costs and savings are estimated as $23.5/t-rolled steel and $1.15/t-hot charged steel with payback times of 5.9 years (US EPA, 2010. p.27).

Japanese flag In a Japanese plant total retrofiting costs were ¥250 million. With a heavy oil price of ¥433/GJ, the payback time was 2 years. 

Hot Charging Publications

Global Warming Countermeasures: Japanese Technologies for Energy Savings / GHG Emissions Reduction

This revised 2008 version of the publication from New Energy and Industrial Technology Development of Japan includes information on innovative Japanese technologies for energy efficiency and for the reduction of COemissions.  

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