Research on the production of dolomite – carbon refactory bricks from the main source of domestic raw materials

Abstract

Dolomite-carbon refractory bricks possess superior properties such as durability against slag and liquid steel, as well as lower production costs compared to Magnesia-carbon refractory bricks. As a result, they are increasingly utilized in the construction of steel containers and furnaces in the metallurgical industry. This paper presents research findings on the production of Dolomite-carbon refractory bricks using domestic dolomite as the primary raw material, which helps reduce foreign currency spent on importing refractory bricks. The study focuses on Dolomite refractory aggregates sourced from dolomite ore in Ha Nam provinces, supplemented with MgO fine powder and sintering additives (0.3% Fe2O3 or 2.0% ZrO2). The composition of dolomite-carbon refractory bricks includes: 89.5% dolomite aggregate (particle size distribution: 3-5 mm: 25.0%, 1-3 mm: 30.0%, 0-1 mm: 16.0%, fine powder <0.08 mm: 29.0%), 7.0% carbon graphite (fine powder <0.08 mm), 3.5% antioxidant additive (Al), and 4.0% phenol formaldehyde glue. The final product meets the following criteria: high bulk density (≥ 2.89 g/cm³), low apparent porosity (≤ 6.0%), high compressive strength (≥ 40 MPa), and a deformation temperature under high load (Tbd > 1550°C).