Chemical reactions at reduction of iron from oxides by natural gas

Abstract

The main component of natural gas is methane CH4 , that is, a component consisting of two active reducing agents for iron – carbon and hydrogen. Previously, computer simulations have found that the reduction of iron from magnetite with carbon begins at 680 °C, and its reduction with hydrogen – at 350 °C. In this paper it is shown that the beginning of the reduction of iron with methane should be expected at a temperature of 530 °C. However, this temperature for natural gas, obtained from gas condensate fields and containing up to 10 % of heavy hydrocarbons and impurities, increases to 550 °C. When using natural gas together with oxygen in the ratio CH4 : O2 = 2:1, temperature of the beginning of reduction also increases to 620 °C. In addition, a calculation formula was proposed for Fe – O – C – H system, which allows predicting the formation of a “pure” phase of iron at 1500 °C based on the chemical composition of the reducing gas mixture.