US1221962A - Process for sintering fine oxid ore and metallurgical products. - Google Patents

Description

H. BITTMANN. PROCESS FOR SINTERING FINE O XID ORE AND METALLUBGICIIL PRODUCTS.

AIPLICATloN FILED 1uLY16,1914'.

Imm Patented Apr. 10,1917.

l orrrcn HEINRICH BITTMANN, 0F FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO DWIGHT @a LLOYD SINTERING COMPANY, INC., OF NEW YORK, N. Y., A COR- POIRATION OF DELAWARE.

PROCESS FOR SINTERING FINE OXID ORE AND METALLURGICAL PRODUCTS.

Specification of Letters Patent.

Patented Apr. lO, 191W..

Appueation'mea :my 1e, 1914. serial no. @5i/119.

Ure and Metallurgical Products, of which.

the following is a specication.

This invention relates to a process of sintering fine oxid ores and metallurgical products; and corresponding to that set forth in Letters Patent of the Kingdom of Great Britain and ireland, No. 8,384 of 1914,

granted upon application filed April 2, 1914.

In the specification for United States Patent 844,355 of 1907 there is set forth va `process for sintering fine oxid ores )and metallurgical products, in which an air blast is blown or sucked through a mixture of ore and fuel, whereby the fuel is lburned out and owing to the heat generated thereby the particles of the material to be treated sinter and bake together. According to the method described in the specification of the above referred to patent, the process is carried out in a converter furnace and in this case is done in an intermittent way, that is to say, after the converter has been filled and after the sintering of the contents of the converter is completed, the sinter cake obtained is removed from the converter by the tilting of the converter and a new charge is fed to the converter and subjected to sintering.

Accordin to a well-known method the above descrlbed process is carried out in a continuous way by means of a grate to which is imparted an uninterrupted or intermittently interrupted movement. The present invention relates to a special mode of carrying out this known continuous ,method According to the said invention onto the farther end of the charge support or bed which is thus moved a layer of fuel (carbon) is charged inI an ignited condition or brought to ignition and this ignited layer of fuel is brought by a` movement of thel base to the place where the ore is fed in. At this place on to the ignited layer of fuel a layer,l of material to be treated is charged and during the further movement of the charge support or bed the air for combustion is passed from below through the two layers offuel and lore superimposed upon each other. Owing to the movement of the charge support or bed the discharge of the sintered material from the forward end of the grate can simultaneously take place.

lln the accompanying drawings there is shown by way of example a device'adapted to enable the process above described to be carried into practice, of which drawings Figure 1 is a longitudinal sectional view through the apparatus, and Fig. 2 is a transverse sectional view.

As charge support or bed for the grate there may be provided a chain grateaor the like, to which is imparted an uninterrupted or an intermittent movement in the direc-` tion indicated by the arrows; b is a feed hopper, at the rear end of the chain grate,

by means of which during the movementefthe grate a layer of fuel the upperlimit of which is indicated by the dotted line -w is charged on the same; and c is the feed hopper containing the ore. 0n the charge support or grate situated between the feed hoppers b and c the layer of fuel is brought to ignition, for which purpose pressure or suction blast may be employed.

A layer of material to be treated which is indicated by the lines y-y is charged on the fuel layer :1e-:r from the feed hopper c. Below the charge support or grate situated between the feed-hopper c and the foremost end of the grate is arranged an air box d, into which air is caused to enter, in order to pass upwardly from here by way of the grate and the fuel and ore layer. On the fore end of the base of the charge support or grate a scraper e is provided which when the charge support or bed is moved scrapes olf vthe sintered material from the latter and brings same into an inclosed ace f where the material may be temporarily ref tained preparatory to being delivered to a car 'or other conveying device by which it is taken away from the sintering apparatus. For conducting away the gases the grate base may be surrounded by a Hue space g flue may be provided with manholes z'.

It is self-evident that for carrying out from which flues h and h extend; and the the process any other suitable form of" iat feed the ore on tothe ignited layer of fuel. l

in several layers one after the other. This can be effected in a simple manner by providing several feed hoppers c arranged m series and provided wlth corresponding.

higher outlet'openings.

When carrying out the process, as a rule less mixing fuel is required as is the case when Working according to the example of carrying out the process in a discontinuous Way described in the specification for Patent No. 844,355 lof 1907, because the combustion of the mixed fuel progresses more intensely. When using a suliciently deep fuel layer and not too thick a layer of ore the mixing fuel in the ore may in some circumstances be entirely dispensed with; in such cases therefore the sintering would be only effected by.

in native condition or artificially formed,

and that include not only metal oxid of one form or another but also other materials that are ordinarily found in these ores such as silica, earthy bodies, etc.

It is Well understood that the treatment of fine oxid and similar ores, which do not carry in any considerable quantities as a component part a native combustible ele-` ment, such as sulfur or its equivalent, in order to sinter or agglomerate` such ores,

v that is, to cause the particles thereof to sintering lores of the sulfd class. Particucohere together and form masses adapted for. blast furnace treatment, depends upon actlvities dlierent from those developed in larly in treating fine iron oxid ores to cause the particles to cohere and form masses suitable for treatment ina blast furnace" it is important that silicating of the metal should not take place, as that is highly undesirable.

The process herein described is especially adapted for treating iron oxid ores, as it permits an easy control of the various steps of the operation and the chemical reactions and physical effects which take place in working the process. The layer of ignited and burning carbonaceous fuel supplies the heat necessary to a working of the process, and also the carbon oxid gases that interact with the metallic oxids of the ore, causing reactions to take place that result in the coheringiof the masses of the ore without the metal being silicated. These reactions take placeiwhile the burning layer of carbonaore being as represented comparatively thin ceous fuel and the ore are iny respective layers superposed one upon the other, the layer of so that the heat generated by the combustion of the fuel layer after performing its neces- `sary work readily escapes by conduction .desirable reactions to take place. It is Well t understood that ores adapted for treatment in a process such as described vary to a con-e siderable'degree, some requiring a higher degree of heat than others for the most desirable results, and some requiring more of the carbon oxids, or a prolonged presence thereof, in contact with the ore, to secure the best results; and the process herein described is adapted to secure the best results in'these respects as by regulating the relative proportions of the fuel layerand vthe ore layer, and also the force and rapidity of the currents that supply combustion-supporting gases, so that amore intense combustion and hence a higher heat, or a slower and more prolonged combustion, may be se- 'cured as circumstances may require, and

, these adjustments may be made quickly and during theoperation of the apparatus as conditions may suggest.

Having now particularly described and ascertained the nature of said invention and in what manner the same is to be performed, I declare -that whatI claim is:

1. The herein described process of treating metal oxid ores that are initially in a fine condition to form therefrom coherent, thin, agglomerated or sintered masses suitable for blast furnace treatment, it consisting in forming in superposed relationship to each other a layer of carbon fuel and a layer of the ore tobe treated, causing the layer of fuel to actively burn `under the influence o'f a current of combustion-supporting gas supplied thereto, thereby generating heat and producing carbon oxid gases, forcing the products of combustion from the said burning fuel layer and the gaseous bodies mixed therewith through the ore layer and causing reactions to takeplace among thev metallic oxid particles thereof under the influence of the heat and the carbon oxid gases, whereby the ore masses are caused to. cohere and form agglomerated masses.

2. The herein described process of treating metal'oxid ores that are initially in a line' condition to form therefrom coherent,

thin, agglomerated or sintered masses suitable for blast furnace treatment, it consisting in forming a layer of ignited carbonaceous fuel, applying thereto a layer of oxid ore to be treated, causing air .to pass through the said superposed layers yto maintain combustion inthe fuel layer, thereby generating heat and producing carbon oXids, and causing these carbon oxids and the gaseous bodies mixed therewith to pass through the superposed ore layer and causwere@ ing the metal omldsun the latter, dueto'het eind;y the' presence of. the cerlomv oxide vpro-'- thin, agglomerated :or sntered messes suit j 10 duced'bythe burningof the fuel leyer, to

cohere and form agglomerated tered. -masses 5 3. The herein described processof tremtf ing metaloxid ores that `a,re'`intially n 'e ne condition to-'orm thereromcoherent,

able for blast' furnace treatment,l it consiste` "tinuing thepessele of air *u'pvvar'clljrv throughA the seidsuperposed leyersend. causing the heat generated-bythe combustion of the ore will; l

layer and the'cerbon oxid gases produced therein)I to passthrough and act-'upon the o remess; whereby the metallic oxids are` n caused'to where-uniform agglomerated or 'jsinteredfmas'ses ofthe ore.

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