Determination of degree of hydrogen usage in blast furnace

. Decreasing of coke rate in blast furnace (BF) process is an actual task, one of methods of its solving being increase of natural gas consumption. Efficiency of natural gas utilization in the process of iron ore raw materials depends on degree of hydrogen usage. Determination of criteria of hydrogen usage degree in a current BF process is difficult, since during the measurements the moisture is fallen as a condensate. Making a material balance of hydrogen in the process of a current operation is also difficult, because a high carefulness is required at sampling which excludes its leak. With the aim of determining moisture content in the BF gas, a hygrometer with wide functional possibilities was designed and manufactures. To control its meterage, in parallel a weighing method was used by application of silica gel, following a material balance of hydrogen. To determine the technological factors effect on hydrogen usage degree, a long-term period of PAO “MMK” BF shop operation was analyzed, in which several periods were selected: purely coke heats, heats with high blast moistening and heats with natural gas injection. A relation between amount of oxygen removed out of the burden and index of non-direct reducing was determined. It was shown, that increase of hydrogen consumption has not direct influence on the index of carbon monoxide participation in the non-direct reducing. The study results received allow to predict the value of criteria of hydrogen usage degree in the BF heats with increased consumption of natural gas. Application of these criteria to calculation