3. Blast furnace knowledge based on industrial observations

Progress in our understanding of blast furnaces has always been the result of direct measurement and experimentation on industrial equipment. Blast furnace operators have developed unique know-how in this field: vertical soundings from the blast furnace head, horizontal soundings at various levels in the shaft or at the tuyeres, combined with material sampling. Quenching of blast furnaces in operation in the USA, Japan, Germany and China has provided a three-dimensional view of the internal state of the furnace.