Abstract: Iron oxide agglomerates incorporated with the carbonaceous material having a particle size within a range of about 10 to 30 nm are prepared upon production of reduced iron agglomerates. Then, the iron oxides agglomerates incorporated with the carbonaceous material were laid thinly at a laying density of less than 1.4 kg/m.sup.2 /mm or lower on a hearth of a moving hearth furnace. Subsequently, the iron oxide agglomerates are heated rapidly such that the surface temperature of the iron oxide agglomerates reaches 1200.degree. C. or higher within one-third of the retention period of time of the iron oxide agglomerates in the moving hearth furnace. Then, the iron oxide agglomerates are reduced till the metallization ratio thereof reaches 85% or higher to form reduced iron agglomerates and then the reduced iron agglomerates are discharged out of the moving hearth furnace. With the procedures, reduced iron agglomerates of a high average quality can be obtained at a high productivity.

Abstract: A thermal sensor for detecting temperature distribution in a deposit layer on the refractory walls of a blast furnace or the like, including a temperature probe assembly having temperature sensing areas at different points along the length thereof, an outer protective casing for accommodating the probe assembly, a number of annular fin members fitted on the temperature sensing areas of the probe assembly and secured to the outer protective casing, and an insulating material filled between the outer protective casing and the probe assembly for thermally insulating the fine members from each other.