DE57883C - Process for producing iron directly from ores - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The invention described below relates to certain innovations in the direct reduction of ores to metallic iron and, together with the reduction of the Ore also an extensive expulsion of sulfur and phosphorus from it.

It was previously used in the treatment of ores with high sulfur - phosphorus content according to the direct method it is necessary to roast these ores beforehand in order to drive off the sulfur, and then treat the roasted ores in the usual way.

In practicing the present invention, the ore is in a Ore mill or other suitable device into chunks of casually crushed Nufsgröfse. The crushed ore is then placed directly on the hot hearth of a flame furnace or other brought to a suitable furnace, which preferably has an ash or cinder bottom, and there exposed to the action of a strong reducing flame, until the water of hydration is expelled and the ore is in a state in which it willingly gives off its oxygen and takes up carbon. If the ore is in this condition is located, about 20 to 40 percent by weight of finely powdered coal, d. H. about 20 to 40 parts by weight Coal for every 100 parts by weight of ore shoveled loosely onto the red-hot ore. The whole mass is then stirred well so that the coal becomes intimate with the ore lumps mix up; the powdered coal is slightly moistened before it is put into the furnace, to prevent dust. After the ore and the carbonaceous material well have been carried out, the entire charge is covered by a light blanket of protected by powdered coal, which is also slightly moistened. The heat is now gradually increased, the flame still retaining its reducing properties, until the iron becomes doughy. It is then clumped together in the usual manner and taken out of the oven.

Although ^s each powdered carbonaceous material may be used in the method is the same but the use of coke, charcoal, petroleum coke, etc. particularly suitable which, when the old method where coal and ore blended and introduced simultaneously into the furnace, cannot be used to advantage because the coal will be consumed before the ore can be heated sufficiently to give up its oxygen and take up the carbon.

. In the case of the present process, however, the coal only takes effect when the Ore is quite porous due to the heat to which it is exposed and the expulsion of the water of hydration has been made. This calcination of the ore reduces its tendency to melt, in what condition it is less permeable to the reducing gas. One sees that the operations which are necessary to bring the ore into a state which is necessary for the beneficial effect of the reducing agent to take place, before the reducing agent gets into the furnace. This results in losses of reducing agent avoided which then

Claims (2)

stop when the ore and reducing agent are put into the furnace at the same time. This preliminary heating not only prepares the ore for the action of the reducing agent, as indicated above, but also causes the sulfur to be removed. • As is known, iron oxide does this. Elimination of silicic acid and phosphorus from the ore. But since iron oxide shows a greater affinity for silicic acid than for phosphorus, the latter can only be removed if more oxide is present than is necessary for the silicic acid. An enrichment of the slag in iron oxide can take place in the process in various ways, for example by increasing the temperature during the preparatory operation, or by adding iron hammer blow to the charge; the latter is preferable in order to achieve an increase in the oxide content. Although the hammer blow can be added to the charge at any time, it is advisable to add it immediately before the carbonaceous material is introduced. The powdered carbonaceous material can be moistened with water or oil or, best of all, water and oil, since the latter, when exposed to heat in the furnace, provides a hydrocarbon gas which, when burned, prevents the ore from detrimentally cooling. If strongly carbonized iron is desired, it is only necessary that manganese be present during the reduction; this manganese can be obtained by adding to the charge in the furnace the slag from refining furnaces, which is a waste product rich in lime and manganese. The procedure is the same whether hematite or magnetic iron stone or roughened ores are used, and the results are equally favorable in all cases. No claim is made on the roasting of the ores in general for the purpose of removing the sulfur, since this roasting has hitherto been carried out as an operation in itself and independently of the subsequent treatment of the ores, in that the roasting and the reduction were carried out in different furnaces . In the current process, however, the ores are roasted not only to remove the sulfur and drive off the water of hydration, but also to prepare them for action by the reducing agent. Godfather ν τ-An s ρ rüche: 1. Process for the production of iron directly from ores, consisting in their being first heated in an oven to the reduction temperature (red glow) and then first, in order to save on the reducing agent, in the same furnace with carbonaceous Material are mixed while after reduction of the ores to sponge iron are formed by balling up lobes. 2. In the case of the patent claim i. marked Procedure: a) the addition of iron hammer blow to the charge; b) covering the charge with powdered carbonaceous material, that is sufficiently moistened to be coherent.