US961121A - Process for cleaning iron ores. - Google Patents

Description

E. F. GOLTRA. PROCESS FOR CLEANING IRON ORES.

'APPLIOATION FILED 001218, 1909.

961,121 Patented June 14,1910

IIIIII I 1 r1 b l nnwA-Rn F. comm, or sr. LOUIS-,7 MISSOURI.

PROCESS FOR CLEANING IRON ORES/ To all whom alt-may concern: I Be it known that I, Eowsno F. Gowns, a

citizen of the United; States,andresidentof St. Louis, in the State of Missouri, have invented certain new. and useful .Imprm'ementsin- Processes for- Gleaning Iron Ores,

of which the following is a specification. I

This invention relates to a process for cleaning iron ores-and; for preparing the same for the subsequent operations.

Some iron ores, as brown hemat1te, contain' a large percentage of clay and sometimes silicaas a angue, and thisgangue must be separated from the ore before it-can be used in a blast furnace.

In my co-pending application, Serial No. 536,403, filed January 4:,"1910', a process is described whereby iron ore is cleaned of its gangue by a; blast.

The objects of this invention are to refine the process broadly described and claimed in the above application so as torender it continuous.

This invention generally stated consists in the operations as hereinafter fully described The apparatus preferably consists of a runwa-y'upon which the ore is thrown. The oreon the runway is subjected to a strong blast so as to dry the gangue and render the earthy, the silicious and any other gangue.

easily separablesfrom: the ore. The ore is tumbled to shake'loosethe gangue from the ore, and the gangue is removed by'the blast.

The runway is preferably in the form of along incl'inedtube or drum, which is rotated about its longitudinal axis, and a hop er 'is located at one'end of the drum for disc arging the ore into the same. The ore in its passage downwardly is heated to dry out the ore and render the ganguebrittle and easily separable from the ore, and the rotation of the drum will tumble and rattle the ore as it dries and. cause the gangue to be shaken loose from the ore and pulverized by "the tumbling action. The'strong blast sweeps,

cleans and washes the gangue from the ore and this gangue is withdrawn from the drum by the blast fwhile the cleaned ore passes along the drum to the discharge end.

The ore as mined must be dried slowly especially if-it contains much clay as a gangue since a rapid heating would cause this clay to be baked hard and burned to a brick and thus it 'would'be impossible or exf Specification of Letters Patent.

Qkppiication filed October 18, 1909. Serial No. 523,091.

lining 22..

Patented June 14, 1910.

ceedingly diflicult to thereafter loosen it from the ore. For this purpose the hot blast enters the drum at the lower end, that is at the discharge end, and when it strikes the fresh ore admitted from the hopper this hot blast is cooled down enough so that its temperature is. sufliciently low to prevent the hard baking and burning of the gangue.

In the drawing the figure is a view showing one form of apparatus whereby the proc:

ess may be carried out. Referring to the'drawing, 10 designates a runway in the form of a t-ube or drum provided with a number of rin s 11, 11,-resting on .a number of sets of anti-friction rollers suitable frame-work, and the hopper 15 on head 13 discharges into the drum. A suction fan 16-is connected to the head 14 and is driven bya suitable motorrso as to create a strong blast inand through the drum 1(). A burner 17 extends through the head 13 so as l to heat the blast. This burner may be an ord'inary oil burner provided with an air blast.

The head 13 is further provided withan air hole 21,- or. air holes, so as-to allow theblast to enter nearthe burner and be heated there by, The head is further provided with a discharge or; outlet 18- for the cleaned ore. The drum is inclined from the inlet tothe discharge end and is rotated by a drivingpinion 19 engaging a gear 20 on the drum. The drum is lined with a 'Theore as mined} is crushed so as to resuitable refractory Y 12, 12. The ends of the drum extend into stati'onary heads 13, 14 which are bolted to a duce it'to'w'orka-ble form. It is not necessary to pulverizeit, but it is'sufficient if it can pass through a two ortwo and one-half 5 inch mesh, This crushed ore is placed in the. hopper 15 and is discharged into the drum 10; The burner 17 furnishes the necgreatest at the lower end of the drum, but at the upper end this temperature will be considerably reduced, so that the fresh wet ore will not be heated to a-suflici'ent degree so as to hard bake the gangue. As the ore moves downwardly it will be tumbled and thrown around so as toknock loose allof the gangue which clings ,toit, this gangue becoming more and more heated and more and more loose, dried and pulverized as it proceeds to--' ward the lower end of the drum. Theore is cleaned and washed of its gangue by the" essa'ry heat and the temperature will be the v blast passing through the drum, the gangue being drawn off by the strong blast which is created by the suction fan 16. The drum 'is made long enough and the speed of rotation is governed so that at the time when the ore reaches the discharge 18 practically all of be subjected to the high temperature as would be the case if the burner 17 were placed at the upper end of the drum.

In the form of the invention shown in the .figure the heat is generated by a burner 17.

It is, however, advantageous in some instances to generate this heat by passing a hot blast directly through the aperture 21 in the head 13,. and into the lower end of the drum I 10. It is also obvious that the ore may be heated in any other suitable manner, therefore, it is to be-understoodthat this invention is not to be limited to the specific means for heating the ore. Where a hot blast is directly used for furnishing the heat the fan 16 may be dispensed with if desired.

It will be noted that the blast'is passed through and above-the ore while it is agitated. The rotation of the drum will cause the ore to rise with the sides of the drum and fall through the blast passing through the drum. In this way the strong blast sweeps. the pulverized gangue clin ing to and surrounding the ore with it, a lowing the cleaned ore to pass down the drum to the discharge 18. The blast seeks out the gangue in the crevices and around the ore and carries it away with it. It will be remembered that the pieces of ore are comparatively large and heavy and therefore in their tumbling motion ractically all the gan e will be knocked o and pulverized.

T e length of the'drum, its diameter, its incline, the speed of rotation and the temperatures will vary with difierent ores and with their condition as to dampness, the amount of clay in them, etc. As a practical case, where an oil burner is used the temperature at the lower end of the drumwill be 2000 F. orvove'r, while the temperature at the upper end will be 300 to 400 F. Inallcases however, the process is so regulated'that the gangue will be dried and ren dered. separable, shaken loose,'and separated, the temperatures being controlled so that the gangue will be thoroughly dried and still dried gradually enough" so that it will not become hard baked. Another important result obtained is that the moisture in the ore is driven oli: during thisprocess, leaving the cleaned ore in a dry porous condition. Thus :tumbling the ore .and its the amount of heat necessary in the other operations is materially reduced.

It is obvious that various changes may be made without departing from this invention, and it is therefore to be understood that this inventionis not to be limited to c the specific arrangements scribed.

The broad process is broadly claimed in my co-pending application Serial No. 536,403, referred to.

Having thus described the invention, what is claimed'is: V

1. The-herein described process of treat-f ing iron ores containing moist clay, etc., as

shown and de'- a gangue, which consists in heating the ore and its gangue at a temperature and for a" period sufficient to drive ofli' the moisture and to render the angue easily separable from the ore, tum ling the ore and its gangue during the heating operation to shake loose the gangue from the ore, and'to pulverize the gangue by said tumblinga'ction, and subjecting the ore and its gangue during the heating and tumbling operation to a strong gaseous blast which sweeps, cleans and removes the gangue fromtthe.

ore. V

2. The herein described process of treating iron, ores containing moist clay, etc., as a gangue, which consists in subjecting the ore and gangue to'a strong hot gaseous blast at a temperature and for a period sufficient to drive oil the moisture and render the gangue easily separable from the ore, tumbling-theoreand its gangue during the heating operation .to shake loose the gangue from the ore and to pulverize the gangue by said tumbling action, and sweeping, cleaning, and removing the gangue from the ore by said blast during the heating and turn bling operation, the blast being applied to strike the drier. portions of the ore and gangue before the damper portions to gradually heat; the gangue.

3. The herein described process of treat- .ing-iron ores containing moist clay, etc., as

acgangue, which consistsin passing the ore and its gangue along a runway, passlng a strong hot gaseous blast along said runway from the discharge to the admission end so 7 as to gradually heat and'dry the gangue and render it easily separable from the ore, gangue in their passage along the runway to shake 'loose the ganguefrom the ore, and to pulverize the gangue by said tumbling action, and sweeping, cleaning, and removing the gangue from the ore by said blast.

Intestimony whereof I aflix my signature in presence of two witnesses. K a

EDWARD F. GOLTRA. Witnesses:

J. H. BRUNINGA, WALTER E. PAUL.

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