Salt solution treatment to prevent the low temperature reduction degradation of haematite pellet

Ranjan, P and Pal, J (2016) Salt solution treatment to prevent the low temperature reduction degradation of haematite pellet. Ironmaking and Steelmaking , 43(9) (IF-0.985). pp. 688-696.

Restricted to NML users only. Others may use ->



Most of the Indian haematite ore shows very high reduction degradation index (RDI) mainly due to high alumina content (>2.2%) and adverse Al2O3/SiO2 ratio (2.0). Several investigators have reduced RDI mostly by suitable flux addition. However, high flux addition makes the pellet basic. In blast furnace, the charge combination of acidic pellet and basic sinter is preferred because, the burden with acidic pellet can accept highly basic sinter. In the present study, the acidic or mildly basic pellets were treated with different aqueous solutions such as, CaO, MgO, MgCl2, CaCl2 and NaCl of varying concentration under vacuum (45 mm Hg) to reduce RDI. MgCl2 solution (8%) has very minor effect on reducing RDI. On the other hand, CaCl2 and NaCl solutions show encouraging result. The treatment with 10% CaCl2 solution reduces RDI of acidic pellet from 86% to 5.8%; while, treatment with 6% NaCl solution reduces RDI to a very low level (2.5%). However, it shows poor degradation resistance at relatively higher (>800°C) temperature. Therefore, to reduce this degradation and chloride input in pellet, basicity of the pellets were increased slightly to 0.25 and treated with 1–2% NaCl solution at room temperature under vacuum. This shows very low RDI (6–10%) with good cold crushing strength (330 kg/ pellet), reducibility (75%) and swelling index (13%) with minor degradation at higher temperature unlike acidic pellet. This pellet will be useful for blast furnace operation.

Item Type:Article
Official URL/DOI:
Uncontrolled Keywords:Haematite pellet, Blast furnace ironmaking, Preventing reduction degradation, Salt solution treatment, Calcium chloride treatment, Sodium chloride treatment
Divisions:Metal Extraction and Forming
ID Code:7644
Deposited By:Dr. J Pal
Deposited On:12 Sep 2017 17:22
Last Modified:20 Sep 2017 15:24
Related URLs:

Repository Staff Only: item control page