GB334500A - Improvements in and relating to the production of metals from ores - Google Patents

Abstract

334,500. Gr÷nwall, E. A,. A., and Nathorst, H. J. H. April 26, 1929. Shaft furnaces.-In a process for reducing iron and other ores by means of carbonaceous reducing agents, the combustible gases escaping at the upper portion of a shaft furnace are partly burnt with oxygen and blown back into the charge, a continual circulation being maintained. In a modification the escaping gases are treated for the removal of carbon dioxide, are partly burnt with oxygen, passed through coal to increase the content of carbon monoxide, and again partly burnt with a further quantity of oxygen before being blown back into the charge. The gases are led off through a pipe 4, Fig. 1, and the carbon dioxide removed by freezing or absorption and returned to the furnace 1 by a pipe 5. Oxygen is admitted by the pipes 11 and partial combustion takes place in the chamber 12, whence the gases are returned to the charge. A furnace particularly designed for the production of iron sponge according to the modification of the invention described above is shown in Fig. 3. The gases withdrawn from the furnace enter a recuperator 33, are led off by a pipe 35 and treated for removal of carbon dioxide; the gases returning to the recuperator by a pipe 34. A part of the gases is now burnt in a chamber 36 with oxygen admitted through a pipe 37 and is then passed through coal in a tower 38. The carburetted gases are mixed with the remainder of the gases in the chamber 39 and led to the chamber 41 where they are burnt with oxygen admitted through the pipes 40 before being led to the charge. Water cooled plates 31 for cooling the sponge and a feeding out device 32 are also provided.