US1378411A - Process of treating ores preparatory to smelting - Google Patents

Description

- UNITED [sTATEs PATENT OFFl CE.

JULIUS HEGELER, OF DANVfizLE, ILLINOIS.

PROCESS OF TREATING ORES PREPARATORY '10 SMEIQTING,

No Drawing.

To all whom it concern:

Be it known that I, JULIUs W. Hneniinn, a citizen of the United States, and resldent of Danville, in the county of Vermilion'and- State of Illinois, have invented a new and useful Improvement in Processes of Treating Ores Preparatory to 'Smelting, of which the following is a specification.

This invention relates to the art of zinc ore smelting and relates particularly to a preliminary treatment of the ore prepara-- ture into the retorts of a smelting furnace,

said retorts being heated to such a temperature as may necessary to reduce the zinc to metallicform and to distil the same.

It is also recognized that for the efiicient and economic smelting of the charge, itis necessary that the ore and reducing agent shall be crushed or reduced to granular form of desired fineness and thoroughly mixed so that the ore and reducing agent shall be in intimate physical association and contact'with each other, while at the same time providing sufficient porosity or openness in the mass to permit free access of heated gases generated in the subsequent smelting'operation to all parts thereof andfree escape of the zinc fumes produced by distillation of the metallic zinc liberated as a result of the reaction between the zinc ore and carbon contained in the charge.

In their very nature, these conditions are conflicting, as the finer the ingredients are crushed the better as regards their intimate associatlon and contact, whereas-the coarser .the granulation, the better as regards the porosity or openness of the mass, and where the granular ingredients are charged into the retorts in a loose mass the size of the particles must of necessity be a compromise etween these extreme conditions, thereby correspondingly impairing the most efficient operation of the furnace. 'Another serious objection to charging the mixture into the.

Specification of iletters Patent. Application filed April 9, 1920.. Serial No. 872,433, S

( Patented May retorts in the form of a loose mass is, the tendency of the ingredientsto segregate in transportation. and handling between the mixer and the-retorts.

Extensive tests andexperiments have been made to meet the ideal conditions of intimate association and requisite porosity by crushing the ingredients to any desired degree of fineness and bri noting the mixture by means of a suitable blnder.

because of complications which arise in its practice and also on account of its excessive cost. The object of my invention. is to overcomethe obj ectionablefeatures inherent in the foregoing processes, and to this end,

it consists in mlxing properly prepared ore and coking coal or other coking material 1n such proportions as may be desirable, both the ore and coal having been previously reduced to granular form of any degree of fineness that will give the most desirable results, said mixture being made as homogeneous and uniform as possible. Said mixture is then 'coked under conditions best suited to the particular character of the coal- :or other coking material employed, whereby the volatile portions of the coal will be driven off, either wholly or in such part as experience shows will give the best results with diiferent ores and coals or other coking materials in the subsequent smelting operation, the entirecharge coming from the oven in the form of coke in which the ore is firmly embedded or cemented and throughout whichit is thoroughly and uniformly disseminated, the ore particles being also impregnated with carbon. The coke is then crushed to any degree of fineness,

which-when charged into the retorts of the smeltlng furnace-will most effectively promote the accessibility and diffusion of heated gases produced b the smelting operation to all parts of the c arge, and the escape of metallic fumes and vapors therefrom. 7

As is generally well knownto persons familiar with the zinc smelting art as at present ractised, where the granular ore and car on necessary for reduction are charged into the retorts in the form of a loose, non-coherent mass, there is a tendency toward segregation in transport and handling from the time the material eaves the mixer until it is charged into the retorts, and that, as segregation results, it'will destroy in large measure, that intimate associa- This system j "18 objectlonable from apractical standpoint tion and contact of the ore andcarbon necessary for the most effective reduction of the ore contained in the charge. By my improved process,'segregation of the ore from the carbon is prevented and the intimate association and contact of the ore and carbon assured, due to the fact that'the ore and carbon may be charged into the coking ovens directly from the mixer. When coking of the coal or other cokin material occurs, the desired intimate assoclation and contact of the particles of ore and carbon become fixed and will not be destroyed or inany way impaired or affected by subsequent handling. v

I have found in practice that this intimate and fixed association and contact of the particles of ore and carbon result both in a very material acceleration of the subsequent reduction and distillation of the ore with a corresponding increase in the daily capacity and yield of the retorts, and also in the recovery of'an appreciably larger percentage of the metal contained in the ore.

In the smelting of zinc ore, it is desirable to prevent the formation and segregation ofinolten slag, which not only tends to settle to the bottom of the retorts, corroding the same and materially reducing the life thereof, but by adhering to the sides of the re torts, renders it difficult to properly clean the same-that is to remove the residue therefrom-and through improper cleaning reduces the capacity thereof, thus correspondingly reducing the size of the charge and the output of the furnace. By my im proved process, these objectionable features are effectively overcome, as it is found that, as the smelting process progresses, the nonfusible carbon particles in thecharge and the ash will form 'a porous, spongy mass,

throughout which the fusible constituents lar form, my invention contemplates the addition to the mixture of other materials or reagents deslrable to be used in the final charge introduced into the furnace, thereby-insuring not only an intimate and fixed association and contact of the particles of ore and carbon, but a correspondingly intimate association and contact to the other materials or reagents contained in the charge.

It is generally recognized that, in smelting zinc ore, the effective reduction of the ore and distillation of the metallic zinc is promoted by the presence in the charge of a small percentage of volatile hydrocarbons and in accordance with my invention, the

presence of such hydrocarbons may be obtained by properly regulating the temperature at which coking is efiected.

In addition to the foregoing advantages,

I have discovered that the coking of the coal or other coking constituents of the charge may be effected in ovens of the byproducts coking type and that the usual byproducts distilled in the coking operation will be unaffected by the presence of the zinc ore and will be equally available for all commercial and economic purposes as are the by-products distilled from coke or other fied, is added the value of the by-products' recovered, the economic results of my improved process very greatly exceed those of any smelting process of which I have any knowledge. I

For the reasons stated, my. invention contemplates the coking of the coal orother coking constituents of the mixture in ovens of the by-products coking type.

The term coking coal as used herein is intended to include all coals of the bituminous .type which have a suflicient amount of the binding or resinic constituent to form a coherent mass upon the application of heat to the point of decomposition or in the ordinary process of destructive distillation. In.

the intent and meaning of the term, all caking coals are considered to be coking coals. In the same manner, the term other coking material as used herein is intended to include pitch residues from the distillation of tar, petroleum or asphaltic material which, upon the application of the usual processes of carbonization, will result in the formation of a coherent mass of coke.

To recapitulate, among the important advantages of my improved process of treating ore preparatoryto smelting as compared with any other processes of smelting of which I have any knowledge, are the following Y 1. It increases the percentage of metal recovered in the smelting operatlon;

2. It accelerates the smelting operation, thereby correspondingly increasing the daily capacity of the furnace;

3. It materially reduces the quantity of carbonaceous material necessary to reduce the ore; a

4. It prevents separation of slag with its attendant objectionable results; and

correspondingly increasing the practical and commercial value of the process.

What I claim is 1. In the art of zinc-ore. smelting, a preliminary treatment of the ore for the pur pose of producing a fixed mixture of zinc ore and carbon, which consists in intimately associating and commingling zinc ore and coking coal or other coking material, and in then. subjecting said mixture to a coking process, substantially as described. g

2. In the art of zinc ore smelting, a preliminary treatment of the ore for the purpose of producing a fixed mixture of zinc ore and carbon, which consists in. intimately associating and commingling zinc ore and coln'ng 'coal or other coking material and in then subjecting said mixture to a coking process under conditions which permit of the recovery of the by-product constituents of the coal, substantially as described.

3. In the art of zinc ore smelting, a pre-' liminary treatmentof the ore for the purpose of producing a fixed mixture of zinc ore and carbon, which consists in substantially associatingand commingling zinc ore and coking coal or other coking material in granular form, and in then subjecting said 'mixture to a coking process, substantially as described.

l. In theart of zinc ore smelting, a preliminary treatment of the ore for the purpose of producing a fixed mixture of zinc ore and carbon, which consists in intimately associating and commingling zinc ore and coking coal or other coking niaterial, fixing said 'mixture by subjecting it .to a coking process, and in then reducing the coked mass to pieces ofdesired size for smelting, sub stantially as described.

5. In the art of zinc ore smelting, a preliminary treatment of the ore for the purpose of producing a fixed mixture of zinc ore and carbon, which consists in intimately associating and commingling zinc ore and coking coal or other coking material in granular form, subjecting said mixture to a coking process, and in then reducing the coked mass to pieces of desired size for smelting, substantially as described.

6. In the art of zinc ore smelting, a preliminary treatment of the ore for the purpose. of producing a fixed mixture of zinc ore and carbon, which consists in intimately associating and commingling zinc ore and coking coal or other coln'ng material, and in then subjecting said mixture to a coking process under conditions which will efiect distillation of a part only of the volatilehydrocarbons, substantially as described.

7 In the art of zinc ore smelting, a preliminary treatment of the ore which consists in intimately associating and commingling zinc ore and coking coal or other coking material, subjecting said mixture to a coking process, and granulating the coked mass to form pieces of desired size fordis-