Blast Furnace Pulverized Coal Injection To Strengthen The Melting Process

At present, 80% of metallic lead is extracted by traditional method of sinter roast—blast furnace reductive smelt, which has disadvantage of high energy consuming, great labor intensity, producing large volumes of low density SO₂ fume which is difficulty producing sulfuric acid. This is not only contaminating the environment, but also waste sulfur resource, so it is critical to substitute traditional method for newly, energy saving, environment protecting lead extraction process. YunNan metallurgical group effectually combined oxidizing smelting part of ISA lead extraction process in MangTe ISA company of Australia with " rich lead slag blast smelt technology" and " blast furnace positive fusion technology" and developed ISA—YMG method, which is a newly efficient .energy saving, lead recovery process.After comparing three mainly positive smelt methods of oxygen enriched smelt, hot blast smelt and pulverized coal in home and abroad, we proposed blast furnace pulverized coal smelt process, and carried out positive smelt trials.The trial purpose is to replace some expensive metallurgical coke with cheap coal, realize hot blast smelt, comprehensive processing cost reduced 10%, fume exhausting accord with country standard.The positive smelt trials were carried out in 3m² blast furnace in LanCang, these trials were divided in to hot blast smelt, pulverizing coal, direct of blowing powder material. Then, we studied pulverizing coal combustion rule and character of explosion and also researched the mechanism of blast furnace pulverizing coal positive smelt process.According to the trials, when brown coal and semi-coke mixed by 7: 3, injection effect is reasonable. In blast furnace pulverizing coal injection lead extraction process metallurgical coke partly replaced by coal and improved furnace situation, alleviated labor density of workman, had great economic and social benefit.Pulverizing coal was injected in blast furnace, metallurgical coke partly replaced by coal as fuel and reducer, this technology was industrialized in Dec 2003 after industrial trials and got better result. Under the conditions of 80～100°C hot blast, m_coke:m_coal=7:3, output ability improved by 10.44%and coke rate reduced by 15%, producing cost descend19.13%, lead recovery was 97.34%. The trial and industrial practice demonstrate that blast furnace pulverizing coal injection lead extraction process is successful and effective.