Production of high-carbon ferrochrome from dry-quenched semicoke

Abstract

The quenching of semicoke by saturated steam (heating-gas temperature 550°C) is described. The working-moisture content W^r in the semicoke is 3.0–6.7% for the new quenching method. As a reducing agent, semicoke has good characteristics: relatively low ash content (A^d = 7.1%), low sulfur content (S^d = 0.13%) and phosphorus content (P^d = 0.029%), and high reactivity (\({K_{C{O_2}}}\) = 4.0 cm³/g s) and electrical resistivity (ρ > 1.9 × 10⁶ Ω cm). In tests, dry-quenched semicoke performs well in the production of high-carbon ferrochrome: decreased power consumption; increased furnace productivity; decreased consumption of chromium ore; and decreased sulfur content in the ferrochrome when Karaganda coal is completely reduced by the semicoke. The optimal semicoke content in the batch is up to 50 kg.