The invention provides a method and.device for controlling foamed slag
fumace conditions in iron bath smelting reduction, which comprises the following steps:(l) judging
whethcr foamed slag is  lencrated accolding to thc change of the following
indcxes in iron bath smelting reduction production: the sccondary combustion ratc of
coal gas, the calorific value of coal gas, semi-coke amount of flue
gas, the total heat load of water-coolcd wall, thc carbon content of molten iron, the semi-coke content of slag, the density ofslag and the FeO contcnt ofslag; and(2) conirolling the
quaternary basicity ofslag to be 0.70-1.10 by incrcasing the ratio
oithe coal injection amount to the ore injection amount based on the original production parameters, to enable the fumace conditions to  fesume  normal
production if foamed slag is generated;-and continuing the production according to the original
production parameters if foamed slag is not generated. The control method of the invention realizes the accurate of the foamed slag and by the change of the various
indexes, the rapid resumption of the normal production is realized and the production efliciency is judgrnent  improved. The control method of the present invention quantifies
the  of the. fumace conditions of the foamed slag and the resumption method in iron bath smelting reduction and fills the gap in the current production technology in the ar1. 1 judgment  bases