What are the factors that affect the content of direct reduced iron powder ?

Direct Reduced Iron (DRI - Direct Reduced Iron) was pure Iron powder or rolling Iron oxide in the Canon of tunnel kiln and rotary kiln temperature reduction of low-carbon porous material, its chemical composition stability, less impurity content, mainly used as electric furnace steelmaking raw material, also can be used as a coolant of converter steelmaking, if through second reduction is also available for powder metallurgy;
Direct reduced iron use of coal-based direct reduction process, mostly through coal-based direct reduction process by low grade iron ore or rolling iron oxide for making sponge iron iron content is higher, and direct reduced iron total iron content is mainly influenced by the following factors:

(1) the reaction of coal has great influence on the reduction process;
Under normal conditions, the carbon gasification reaction is the limiting step of the reduction process in the reactor.
When the reactive coal is used as reducing agent, the total iron content of sponge iron will be reduced.

(2) carbon distribution;
It is believed that the higher the carbon content, the faster the reduction speed and the shorter the reduction time.
In the process of direct reduction of cattle production, in order to accelerate the reduction speed, the excess carbon amount is usually added to the theoretical value of 1-2 times, which is conducive to the reduction process in a relatively short time.

(3) reduction of roasting temperature;
Temperature has a catalytic effect on the reduction of iron oxide and the gasification of carbon.
The reaction rate is 71.30% when the temperature is 850, and 99.5% at 1050, so the increase in temperature is especially important for carbon gasification.

However, the temperature increase is limited by the soft melting temperature of ash. Therefore, the temperature in the reactor should reach the maximum limit in order to shorten the reduction of roasting time.