Advantages and Disadvantages of Charcoal

In this post we share the advantages and disadvantages of Charcoal that based on research of J.G. Mathieson and his friends. The charcoal properties, which are most relevant to ironmaking, are shown in Table 19.3, along with how they may affect processing in an integrated steelplant, in comparison with conventional fuels and reductants.

Charcoal property

Advantages

Disadvantages

Low ash

Generally provides higher-value products

 

Ash composition

CaO content may save on BF or sinter flux

If biomass is grown in saline soil, alkalis (reported as K2O and Na2O) may approach BF limits in rare circumstances, requiring selective sourcing or blending for CPI

Controlled VM

Flexibility. Allows graded properties, simulating coal types and coke

 

High combustibility

Greater than coal for the same VM content, that is, improved heat balance as a BF injectant

May be too high for full coke substitution in sintering without modification (densification)

High reactivity to CO2

Greater than coke in BF shaft, permitting lower temperature of thermal reserve zone (TRZ)

May lead to premature coke weakening in the BF if used as a high-percentage coking component

Low mechanical strength

Easier to grind for some applications

Unsuitable as a full substitute for top-charged coke in large BFs

Low density

 

Higher volumes for transport and manual handling

High moisture absorption

 

May require protection for some applications, for example, storage in airtight bags. Difficult to dry if saturated

Contamination

 

High surface area and high porosity promote contamination of charcoal fines by incidental contacts with dust and soil, requiring precautions

    Table above indicates some strategies to minimize charcoal’s disadvantages. Charcoal’s low density and high porosity adversely affect several areas, for example, mechanical strength, combustibility in sintering, reactivity as a coking component, high moisture absorption, and ease of contamination.