Experiments were conducted in a laboratory installation (Fig. 1) designed to model the process of preparation of iron sponge in an electric shaft furnace with briquetted charge material and converted naturai gas moving in opposite directions, as performed at the Dneprovsk Aluminum Plant. In the 28-ram i.d. reaction tube (shaft) i were placed 22 perforated heat-resistant cylinders measuring 25 34 mm each. The automatic control system 8 ensured that the reaction tube 1 moved within the Silit rod furnace 2 at speeds corresponding to 15- and 20-rain cylinder travel cycles. The heating zone of the furnace was 250 mm tong. The temperature in the furnace was maintained constant by a control system containing the thermocouple 4 and the PSR-1-02 potentiometer 3. In the reaction tube, empty cylinders alternated with briquet-containing cylinders. On the level of the 21st cylinder, the cylinder tube was provided with a gas outlet tube, which made it possible to sample and analyze, using a KhL-4 chromatograph, the atmosphere along the height of the shaft above the compacts during their reduction. The temperature in the reaction space was measured during the reduction process with the aid of the potentiometer 10 and the thermocouple 9. Incorporated in the installation were systems for preparing and monostating the gas being tested and measuring its rate of flow. In this study, experiments were carried out on finishing mill scale from the Zaporozhstal' Plant, containing 75.2% Fe, 0.08% C, 0.005% S, 0.008% P, 0.04% Si, 0.27% Mn, 24.7% oxygen, and 0.13% of a residue insoluble in HCI. The scale had an apparent density of 2.1 g/cm 3 and the following particle size distribution: