US2658813A - Process of selectively chloridizing manganese in the treatment of materials containing iron and manganese - Google Patents

Description

Patented Nov. 10, 1953 PROCESS OF 'SELECTIVELY CHLORIDIZING MANGANESE IN THE TREATMENT OF MA- TERIALS CONTAINING IRON AND MAN- GANESE Irving P. Whitehouse, South Euclid, and Marion Ernest Graham, Parma, Ohio, assignors,1 by mesne assignments, to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey No Drawing. Application October 5, 1951, Serial No. 250,032

7 Claims. 1

The present invention relates to a process of selectively chloridizing manganese in the treatment of materials containing iron and manganese. More particularly, the present invention relates to the treatment of materials, such as ores or semi-processed materials, which con,- tain a preponderance of iron, usually in oxide form, and a relatively small amount of manganese, which may also be in oxide form, for the selective chloridizing of this material to produce a mixture of manganous chloride (MnClz) and ferrous chloride (FeClz), wherein the proportion of manganous chloride to ferrous chloride is at least about 1:1 and preferably about 4:1- or greater.

It has been known for some time that iron oxides, whether the iron be in the form of FeO, F6203 or F6304, may be reacted with hydrogen chloride (HCl) to form ferrous chloride. It is also known that manganese compounds, such as manganese oxides, may react with HCl to form manganous chloride (M11012). The prior art teaching generally is that the tendency of these two metallic oxides to be converted by reaction with HCl to the corresponding divalent chlorides is approximately equal. It is also known that if either iron or manganese is present in a material, alone or mixed together, they may be reduced from a higher valence form to a valence of two respectively by reduction with hydrogen. The combined reduction from a higher valence form to a valence of two and the conversion of the divalent metal to the chloride by reaction with I-ICl is known as to each of these metals individually. As far as is taught in the prior art, the tendency of the combined reduction and chloridizing reactions, as to each of these metals individually, is about equal. Based upon these known facts, it would reasonably be assumed by those skilled in the art, that if a material containing both these metals, in most or any of the forms in which these metals occur in nature, were exposed to a gas containing both hydrogen and HCl, the metals would be appr ximately equally converted to the respective hlorides. Thus, it would reasonably be expected that if an ore were treated in this way, and if the ore contained substantially more iron than manganese, as-in the case of most naturally occurring ores of these two metals, the resulting chloride mixture, to the extent that it was formed, would contain the two metals in approximately the same proportion as that in which the metals were present in the original ore. This normally expected result is based upon known activities of these two metals as aforesaid, both from the chemical and the thermodynamic points I of view.

The present invention, however, is based upon an unexpected discovery, in that it is found that when a material, such as an ore or semi-processed material resulting from an ore, containing both iron and manganese, wherein theamount of iron present'is substantially greater than the manganese present, is treated with a mixture of HCl and hydrogen, with or'without-other gases which are relatively inert insofar as the present process is concerned, the manganese is converted to manganous chloride to a far greater extent, at least at the firstportion of the reaction, than the conversion of the iron to ferrous chloride. Thus, if such a solid material, as a natural ore, is maintained in a reaction zone at a temperature in a desired range, which has been found to be from about 300 F. to about 900 F.,

and more particularly and preferably from about j 400 F. to about 800 F., and if the gas concentrations in the reaction zone are within certain desired limits as hereinafter set forth, the manganese will be converted to manganous chloride before too large a proportion of the iron is converted to ferrous chloride. This discovery may then be taken' advantage of by stopping the process at the proper point to produce a soluble material, as a mixture of the chlorides of these two metals, which may be further treated in any desired way,'some of which will be mentioned hereinafter, to produce a valuable mixture or;

The present process may be summarized, there- I fore, as one in which a solid material'of the' type hereinabove described is treated in a re-v action zone with a gas containing hydrogen and HCl, and at a temperature in the desired range as aforesaid, for a period terminating at a suitable time, so that the final product will contain atleast 50% of the manganese initially present in the form of mangenese chloride (MnClz) and a relatively small proportion of the iron, not more than the amount of manganese as an outsidelimit, and preferably substantially less. This amount of manganese may be considered in respect to the iron either on a mol basis or on a weight basis, as both are substantially the same) 3 due to the similarity of the atomic weights of the iron and..manganese. If the process were carried on-under' substantially the same conditions as herein contemplated, but for a too long time, it is recognized that more iron would.

be converted to ferrous chloride, so that the selectivity according to the present invention,

would be effectively absent. Thusthe-presentinvention specifically contemplates terminating the operation of the process at a time when the chloridized material has a desired composition,

This will be set forth in greater-detail1hereinafter.

Turning now to the details of the-present-process, the first thing to consider is the composition and character of the raw materialgwhich may be treated according to the present process to p,ro-.

duce results desired in accordance therewith. This material includes many naturally occurring ores as such. Among such ores which are contemplated for use in accordance with the present invention" are 7 (1) Georgia Ochre ore which is found, as' thename" implies; iii-various parts of the state of Georgia; having atypical analysis as follows Per cent Tota1 E'e 42.40 Ignitionloss 12.94 sii. 10.87 4.70

f 0.32 M' ol p 2 Ba' 5Qr;, .50

(2) Red Aroostookmre which-is found in Aroostook County, in the-State of Maine, and having atypical analysis as-follows Per cent TOta1 F'e Ignition losse 9.51 SiOz- 15.38 Mn-- 12.09 CaO 4.47.

(3) Blue A'roostook ore, also .found in A'roostook. CountyQin. the StateofMaine, havinga typical analysis as follows:

Per cent Total Fe I 2853.. Ignition. lcss 7.94.. S102, 14.39 Mn 8.41. cao. f 3.65

1t is also ccntemplated that variousconcene trate .-.or--'semi prmessed-materials, including materialsmade from the -ores ---aforesaid,- may be similarly treated by the process or I the present invention. It is iurther-contemplated that materialsresulting from other processes-and-Which of. theepresent. invention;

n -con emnla edii n se srr w mat r alsrin. ace

no tdence.w ththispmcessi. flow rer, practically).

4 all iron-manganese ores include a substantial preponderance ofiron in..respect to, manganese andare, therefore, to be consideredas; suitable raw materials on which the present process may be practiced.

The next factor to be considered is the particle: sizesrequired :for the solid material aforesaid, for treatment accord-ing to the present process. Inasmuch as-this is a gas-to-solid type reaction, relatively small particle size is usually desired.- This willatend to increase the gas-to-solid contact-and, therefore, will be desirable according to the-.presentiprocess. On the other hand, relativelylarge particle size, such as 8-mesh or larger, will introduce substantial difiiculty, if not the.,comp lete, impossibility, of contact between the gas and the material in the center of each largeparticle. As such, therefore, in the event that the original material to be treated is in relatively large particle size, it is desirable that it -be suitably comminutedin: any desirediman ner, to bring .the particle sizedown tofia' point: such that reasonably complete gasto-solid con tact is .available. Some .of the naturallyoccur- I, ring ores, such .as Georgia: Ochre, are normally: inth'e form-of fine-particles. With-this type ofore, little or no comminution is necessary. On the other hand-,- other'types -.oi ores such astedor .blueAroostookrore are in the form-of rela-tively large. hard lum-ps which should-' firstbe' com minutedbefore continuing with :the steps of the presentprocess, per set It is usuallylpreferredthattheore be of vaparticle si-zecf 50-=mesh::and-- finer and preferably 100.mesh and finer-4- On the other hand, particle size is not absolutely critical ash; is: essential. onlyto obtain good :gas-to-solid contact during the reaction:-

The. next .factor. to: s be considered is the type of apparatus. in which .the process is tobe carried on.. Inasmuch. as :the. processeinvolves a, gas-to solid. contacta reaction atLa temperature-whichis s elevated .in respect to room temperature; any: apparatus providingtheseconditions may b'esuit able forusez. As many typesof apparatusiare now: known WhEIGlI1;Sl1Gh..- conditions .may: be :main tamed, .no. one. apparatus. :iswparticularly critical-I and; none is iilustrated in" connection: with: the present; application; Thesessential characteris-- tics requiredior; the apparatus 1. tobe-used, are: those which, shouldfprovide good gastoesolid -'con- W tact, and which .should; :provide: for-the -ma-intee nance-of. the desired: temperatures for-the reac tion. In. generaL. continuous types of apparatus are preferred :in respect to intermittent cr batchi types, as thecontinuous types offer greater pro dllCtiOn'JiIli a given time. It isporitemplateda for example, that suitable fluidizednbedstype appa ratus ;is desirable for .use; as :this type of appa ratus,. .which'-isfnow well known in the-art oifers a-maximum. .gas-to.+solid. contact, whilepermit ting adequate; temperature: control. It is also" contemplated that suitablerotary kiln-type apparatus: may: bemsed; and it is' =noted in-'-this connection .thattthis. type: oi: apparatus 1 was -in-fact used in .connectionsvwithemany of the examples of this .aprocess hereinafter" set -fortl11-= In such apparatus a good gas-to solid' contact isafforded accompanied, by: a: substantialdegree of agitation, so: that :the gas can reach and react w-ith stantially. all i the particles-of 1 the solid Ina-- terial: Other. types of gas-to-solidcontac-t ap paratus, as=.will occur tothose-skilledintheart; preferably accompaniedlby ,agitation: means;- are also to be;considered:asfeasi-ble and operable in ying out rtherpresent sprocess. For bhe puri 5. poses of the present application, any and all such apparatus is generally included in the term reaction zone into which this solid material is introduced and/or through which it is passed for the purposes of the present process.

The next factor to be considered is temperature. It has been found that the present process may be carried on advantageously in a temperature range having as its extreme limits from about 300 F. to about 900 F. It is noted that these temperature limits are both relatively low in respect to the temperature limits normally contemplated for the chloridizing of iron oxide-containing material with HCl where manganese is either absent or wherein the selective chloridizing of the manganese in respect to the iron is not particularly desired.

The reasons for choosing the present limits are that at temperatures as low as about 300 F., the hydrogen present in the gases as generally set forth hereinabove, does not seem to be particularly reactive to reduce the iron and manganese from a higher valence to a valence of two. Thus, for example, some of the iron may be chloridized to form ferric chloride (FeCls) and the hydrogen present be relatively inactive to reduce this FeCls to FeClz. Inasmuch as the present process is intended to make ferrous chloride, to the extent that any iron is chloridized, as distinguished from ferric chloride, the temperature of 300 F. is selected as the effective and practical low temperature limit of the process.

The high temperature limit of 900 F. is chosen by reason of the desired selectivity of the reaction becoming progressively less as the temperature rises. Thus, at temperatures at or above about 900 F., the iron tends to chloridize almost as fast, if not faster, than the manganese. As such, at temperatures above about 900 F., selectivity, which is the principal feature of the present invention, is effectively absent. For this reason, therefore, about 900 F. is considered as the top limit for temperature in accordance with the present invention, and to attain the desired results thereof.

While the extreme limits have been chosen for the reasons aforesaid, a preferred range of temperature from about 400 F. to about 800 F. is set forth herein, these preferred limits being chosen based upon the same principles as set forth above as to the outside limits respectively, but with a purpose of keeping furtheraway from the difiiculties which cause the outside limits to be selected as aforesaid. Within this narrower preferred range, the desired results according to the present invention, are more certainly attained.

Another aspect of temperature is its general efiect upon the rate of reaction. The present reaction, as in the case of many other chemical reactions, occurs more rapidly at higher temperatures. Thus, if it is desired to employ only a relatively short time of contact between the gas and the solid material, operations in the higher end or portion of the temperature range aforesaid are usually preferred. On the other hand,

it must be kept in mind that the carryingon of the reaction is progressively more expensive as higher temperatures are used, due to the greater amount of heat required and the loss of such heat as sensible heat of the solid material at the completion of the reaction. The desired temperature may, therefore, be chosen finally based upon an economic balance between the speed of the reaction in the higher temperature ranges and the increased cost of maintaining the process while operating in such higher temperature ranges.

The next factor to be considered isthe gas composition. In general, the gas must contain both hydrogen and H01. The requirements and effects of these two gases will now be separately considered.

As both the iron and the manganese may be in a valence state greater than a valence of two in the original material supplied to the process,

some reduction of one or both these metals to a valence of two is usually necessary. Also, in the event that either of these metals were converted to a chloride having a valence greater than two, it is desired to convert such chloride to a divalent state and to reconstitute the remaining chlorine as HCl for the continuance of the reaction with unchloridized solid material. Thus, it is essential that some reducing agent, as hydrogen, be present. On the otherhand, inasmuch as reduction is the only need for hydrogen, there need only be enough hydrogen to assure that ther is always some hydrogen available to effect such reduction as may be required. In order to assure this, it is found that if the gases leaving the reaction zone contain at least some hydrogen, or in other words, contain at least a trace of hydrogen, then there is an assurance that there has been enough hydrogen to do everything that hydrogen can properly do. For this reason, therefore, the concentration of hydrogen in the incoming gases is not particularly important, but the presence of some hydrogen in the outgoing gases seems to be essential to assure the presence of hydrogen throughout the reaction. Excess of hydrogen does not appear to be at all harmful, as such excess hydrogen acts merely as an inert gas, insofar as the desired reaction is concerned.

As to the upper limit of hydrogen, it may be considered that there is always a possibility that hydrogen might react either with one or more of the oxides of iron, to reduce the iron from the oxide form to a metallic state or to reduce ferrous chloride to metallic iron. It is found, however, that either of these reactions will take place quite slowly until the uppermost range of temperature, in accordance with the present invention, is reached; and further, that the presence in'the gases of some HCl will tend additionally to depress the rate of reduction of iron to the metallic state, irrespective of the iron compound which is to be reduced. On the other hand, it is practically impossible, in the temperature range according to the present invention, to reduce manganese to the elemental or metallic state with hydrogen, so that this possibility need not be seriously considered. As a practical matter, the presence of HCl in the concentrations normally used as herein set forth, will preclude all but a substantially negligible reduction of the iron to the metallic state except, perhaps in the temperature range above 800 F., and even at these temperatures, the rate of reduction of the iron is relatively slow in the presence of substantial amounts of HCl and is also retarded by water vapor. This possibility may, therefore, be effectively disregarded when operating according to the preferred range embodiment of the present process, even with the maximum amount of hydrogen permissible by differences between the amount of HCl present as hereinafter set forth and The only efiective limit, therefore, upon the hydrogen concentration is that there should be sufficient hydrogen, so that the exit gases will contain at least a trace of hydrogen.

73 Examshse i: eehyd eene qn ntrat oii:i s hea gases as actually used in the practice of the proo sa w za pe r nvt e am e hich .io p

The .;-otherl essential; ingredient in the gases which are passed through the reaction zone, is HGL; This gas, (H01) :is-requiredfio convert mall-I, ganese and iron, which has been brought to -a valence of two by the hydrogen, to, MnClz and F8012 respectively. view.,-of the --fa, ct that the; purposeof -,theprocess .is primarily to convert the, manganese present to MnQlz, ,,there. should be sufficient HCl present to-rlo,this. Thus while the total amount otHCl to which the solid ma terial is exposed. .while it i is in the, reaction :zone is hot-exactly critical, it is usual and islpreferred to, su ply at least enough HCl into contact with, theisolid material, during. the total period ct con s tact between the: solid material; and the;gases-,-, to. convert all the manganese-present .in the-solid material to MnClz Thus: while theU HClcon centration in the gases may beivariedin differ; l ent tests or in different operations, during which, the .process is practiced, there mustalways be sufilcientHClto convert the,- amonnt of,-ma n-. ganese to MnClz, Whichitis-desired to so;.con-.. vert,. and preferably also. enough to. convert .all. the manganese present to MIlClz. On the other; hand, itisinotdesired to convertiron to Feclz, except to the extent thatsuch conversionissun avoidable and ,isdncidental i to. v the desired ,con-. U

version of manganeseas aforesaid For this rea-, son,- theiron .contentotthe, original raw material is not considered determining how .much .HCl is to b'e used. Normally, it is, quite usual to, use morehthan enough HCl ins-respect .to thBStDiChiOr metric, amount required to convert all the. man-.- anese ,present ,towMnClahfor example, one and one-half times as, much as thisstoichiometric amount. Under most circumstanceahowever, this ratiois probably to be considered as a high, limit; as it isnsuallyundesirable to use substan1- tiallYmoreHCl than is necessary, assuch excess H01 tends to increase the .chloridization ,of the. 1 10 1 Th us far, the discussion h' as appliedjo the, totaljiam unt HQ1;in. .th eas sin contact with y\ particular por i n f the solid material ,durins. the a pa s e f; such portion throu h h reaction, zone, or while, such rportion is in the reaction zone, asin the case of a batchtyper op erationfas to thesolid type material; The' q htrationh i CLi e as i Q-t par.- ticularly critical.,, The. essential feature isithatr durin the timeany portion of the. solid m a teriali in contact Withfihfi gases, suffieientI-LC}; willbe brought into contactstherewithfltofiefer feet desir,edresul,ts., This can beaecomplishedi therefore, by, using a lower concentration and at longer time, However, in view oijthe fact that." time. is in most instances directly related .to the. economy-f the process, it is usua rto supply n HCl concentration such that the process maybe, completedgto the extent desired in anreasonable times Thus, Whilethe concentration, of HCLin hesases is. not acritical factor, it is usu l 130 use at least 6%1-101 by volume in the gases,.and, preferably somewhat more, as illustratedbythei examples, which ,follow.

Thergasespassed throu h. the reactio zone as: aforesaidmay also contain moraor. lessdnert gas, by, which is meant gases which are-inert. insofar as the present reaction is concerned, as; well as those gases which are generally accepted as. inert per, se, such as, nitrogen. It is, desired, of, coursef that there be nothing; in, the-- gases 8: hemselr st eh li; n, er-ie af iths hea e itei-z s r om w ,sto s s he. o e.-,., ee i r tionai ases;w ch-, r -ma not r sents, other than'the essential gases such ashydt-Ofien and HCl, may beofsany desirednatureandmay be epresent in any .desired; amount ofv concentration,- as long -as they do notinterfere suliystan lv tiallymith the; operation of the ,process ,as ,here l inset; forth; Examples of gaseous-mixtures in luq issmo less n t a es e tilfi h e e aiter.-..

Th i-nexti si nt 1- nsicl ed sh aths-2% tionof the-operation of the process, that s; thee time of; exposure-oi; the. solid; material in th rea t on; ne; os a ee eo s.-. x ur ra s a; her t cueha la; h ipe t e; in; 1111 zone is suitably controlled and maintained as ajoresaid The processshould-be carried- 0 a time periodjsufficient to convert ;.a desireii gaxyi 20 bstantia a ount ft-t zman enes s sese i tee manganous chloride (MnC,l2);. Foiythe purpgsesy, obthe presentE application, this time period is selected as- -that in which at; least Q-% 0L th manganese; present may; be thus-l-convertedor Ql di d-=' Norma y; yi ds u stant ally: r ate t an: 5 i. .the; m n anes int e or of manganous chloride are desired; and; re fact attained-,as -.il-lus trat edby many oii th, e ampleswhich follow; On the 0thelhandp theQ pr e so l not eo n ed; o i u hi a one: periodthat iron is converted-to the form ot fer rous chloride -to an undesired e rten In-, OthQi Words, it; is essential thatv the-i process be; npt continued too-long; This be determined practically and, wi-th v avery; -fe experiments ;by; the, composition: oi the: resulting; solid matergi d y; also. e et rmihe i o i anperatip point of View by theecompositionno f e: ea e mpar da i hehompeei ion LOI. he: e asesbeina pl ed a t he: ac ion;- e eiu hes t pl i-such s shsiher nowhwrime: determined, For example, ii -may be desired te make a product whiclr willcontain abo, 8 M1 1 n e-Gl cons dering-,1 n y; he: chloridized material). Under such; ci ances h e mpu iti iimrri e net h.l

ized, tends;to exceed, about one, a part 1 for; every; our ar s-h man a e h eii-i ze s t siseec erally about vtime to stop the; process; a a, con: tinuance-of i the process follow-i-ng this tir-ne :w ll; u -ti nmuci-iimose on bein hlorid r d; manganese Examples or ;the amounts and prp s portionssof' iron and manganese; chloridiaed will; e i n, r it i; lus t n -1 wthe time; for =cessation oi i the process inay bereadily de: 4 m -ned 'e fi thos i e in the art .for h r ive iz set of conditions. While no absolute theory can; begivemwhjeh will-explain in detail or in fu-l -l zthe desired;re SUltS-sWhiCl-l areFinfaet attained-byi-the prese ta: process, itis believed-that when startinggwith mat rial inc d ng a. mflonnmtiom t: 39111: someoxide form, and a-relatively; non; portion; f ma an s ome or m xamp e, ha xide. formh r h s; which: appen are: the simultaneou reduction-oi the-two metals tqg a divalentstateand then the -conversion 5O5S01I3 of the, iron to a; chloride forrra Following: this;; itrisbelieved that-an interchange;reaction;o curs between-ferrous chloride and Mn 1va FeQ plus -MnCl2l; Theextent to;which-;th is ing, terehang ereaction oecurs; as; contrasted; with; the rateat which manganese pxida-ischloridized; y direct t on {with theeases s hotnown; HQWQV t is; lieved thatdhe surprising res--- 'sults of the present process in the selective chloridizing of the manganese as compared with Z Once the process proper has been completed in accordance with the present invention, it is desired usually to separate the chloridized manganese and iron from the remaining material. This can be effected by a leaching operation, due to the soluble character of the chlorides as contrasted with the insoluble character of the remainder of the original material, thus, the solid material resulting from the process, after it has been removed from the reaction zone and cooled to room temperature, may be leached with water ing to the present invention. However, even in to dissolve out the soluble chlorides, then the solution separated, as by filtration or decantation, from the insoluble material, and the soluble material recovered from the solution by evaporation.

' Another way in which the manganese and iron chlorides may be removed from the remaining .2

material is by vaporization that is, by heating the solid material up to a point where MnClz and FeClz will both vaporize. By condensing-the resultant vapor, the chlorides may be recovered.

By the use of a suitable gas, such as nitrogen or any other relatively inert gas, the temperature of vaporization of these chlorides may be brought down somewhat below the normal boiling points of these two chlorides as will be obvious to those skilled in the art.

Irrespective of the way the chlorides are separated from the remaining-material as aforesaid, the metals may be recovered from the chlorides in any suitable way, forming per se no part of the present invention and which, therefore, are

not specifically disclosed herein.

As illustrative of the practical operation of the process, the following examples may be given:

Example I This example is given to illustrate the selective character of the present process asapplied to different types of raw materials. For the purpose of this example, three different types of naturally occurring ores were used. In each test hereinafter given in this example, 150 gramsamples of the ore was supplied to a rotary furnace three inches in inside diameter and five inches long. A gas composed of hydrogen and 20% HCl Was passed through this furnace for one hour, the rate of gas flow being such that during this time period, one and one-half times the stoichiometric amount of HCl was passed through the furnace, calculated in respect to the amount of H01 required to convert all the manganese present in the ore to MnClz. In each test the material in the furnace was maintained at about 600 F. In the first test hereinafter given a relatively easily chloridizable ore was used, so that the results stated show an adequate amount of chloridizing in accordance with the present invention; while in the other tests relatively difiicultly chloridizable types of ores were used, so that the time period permitted was inadequate to effect the desired amount of chloridizing, accordthe later tests, the selective character of the chloridizing is apparent.

A. Using Georgia Ochre ore of the composition given above and under the conditions stated, it was found that the resulting solid material contained 3.31% soluble manganese (as MnClz) 0.95% insoluble manganese, 1.75% soluble iron (as FeClz) and 43.2% insoluble iron. Thus 77.5% of the manganese was converted by the reaction to MnClz, while only 3.9% of the iron was converted to FeClz. In the soluble product, there was a ratio of manganese to iron of 1.9:1.

B. In this test Red Aroostook ore of the composition given above was used. Upon analysis of the solid product of the reaction, there was found 3.9% soluble manganese, 8.7% insoluble manganese, 0.4% soluble iron and 29.7% insoluble iron. Thus 31% of the manganese was converted to MnCh; while only 1.3 of the iron was converted to FeClz. The ratio of the manganese to iron in the soluble final product was very high in this case, although this ratio 'is not considered as conclusive, as the process was not carried on for a sufiicient time for this type of raw material during this test. The selectivity, however, of the chloridizing is unquestionable.

C. In this test Blue Aroostook ore of the composition given above was used, giving a resulting solid material containing 2.87% soluble manganese, 6.91% insoluble manganese, less than 0.1% soluble iron, and 30.1 insoluble iron. Thus, the manganese was 25.5% converted to MnClz, while less than 0.3% of the iron was converted to Feclz. Again the test was carried on for too short a period of time to give proper results from the point of view of the present invention or to determine the eventual ratio of manganese to iron which would have been attained had the process been carried on for a time period adequate for treating this type of ore.

Example II The purpose of this example is to illustrate the effect of varying temperatures on the reaction.

I In all tests in this example Red Aroostook ore of the composition given above was used.

A. In the first test illustrating the operation of the process at a very low temperature, a 3.5 gram sample of the ore in a finely ground condition (all through 325 mesh) was exposed in a still bed to a gas containing, per minute of gas flow through the reaction chamber, cc. HCl, 15 cc. H2 and 1520 cc. N2. The temperature of the reaction chamber was maintained at about 300 F., and using a 360 minute test time period, the resulting product upon analysis, showed that 48.0% of the manganese present had been chloridized to MnClz, 2.8% of the iron had been chloridized to FeClz, 7.8% of the iron had" been chlorized to FeCla. The ratio of manganese to iron in the soluble portions of the solid product was 1.66:1. This test is considered to show that at this low temperature the reaction is quite selective, but due to the low temperature and to the presence of only a very small amount of hydrogen, a considerable amount of the iron was chloridized to ferric chloride, rather than ferrous chloride.

In a further test with conditions otherwise the same but with the temperature held at about 400 F. for 180 minutes, it was found that 72.5% ofthe manganese was chloridiz'ed to MnClz and 6.3% of the iron was chloridized to FeClz; In this test there was no FeCla found in the final pro'duct. "Thus this testgave afi-solubie":product having a ratim(if manganese to' iron' ofi4f47iz 1.

B. This test was carried-:on -at a higherfltemperature' within the preferred;:rangegini 'thisiease 1 :conneotion rwith Example' I, andeusing? 150 anesh ore "(Red Aroostook .Of i the r compositioniigiven :aabove). 'ilThe gas rates zinfithis test'ztper minute) were .510 ices-Hz: and 50 :cc. The zgasiwas -.spassedrthrough theifurnaceifor astotal time-f tuIBZL-minutes, cduring zwhichztimei 110%401? zithe ilStCiChiOmEtiiC amount of'I-ICI 1(torconvertrall; the

a manganese present tolMnClz) :passed throughthe iiurnace.

ilimaifirstxte'st under theserconditions carriedron :zatw'GOO"; E; 55.9 r; of :thetmanganese was chlorridizechtdzMnClaarid 82% :of-the iron'zwaszehloirridized': :torFeClae giving a: solubleztprodu'ctzmavring-;.a ratiopofmanganese to- -iromoi2.66: 1.

Inca; second: testz under theses conditionsnbut awitlrtheztemperatureat 8.00??1i.-; itzwas found that (F-79.4% :of the manganese was :iohlo'ridized mto jsMnClz; :while 811%.: of: the: iromwasmhloridizedvto cFefllaz-zgivingaaw manganesewto: :iron ratio inwzthe 'rawaten-solubleiproduetqof-3.823 1.

C. A=iurthertestrwas=carried on=;at.the "extreme high limit of temperatur e;:900.-:F.; inva'ocordance ewith; the.'present;. invention; ithis test? being under -,-the ssa'merstillnbedaconditions .zdescribed win: re-

.; spect; toi-ExamplezII ,(--A) sand using-1a: 6:9 gram .esamplesofi the sameReduAroostook ore; the':com-

,vposition Of 'WhiChJi-Sfi; given above. SThiSifSaZmPIB :"was ground w to ea-lla-m'inus 2-100 :mesh. The @test :was' r-unsforiza periodeof. 5240-: minutes yusing lcn 1 cc.-of HCtand ilaccsofeHz, both perminute. .The sresultingz-amaterial ;contained:-89=4% of thex-Mn =;.-present--:as -.Mn1a-:and:.-58;6 %-:of ;;the FFe: present was FeC12, givir :a ratioaohmanganese-to ironfin ithe soluble. productof;-0;61; 1. :This'ttest isg'given to .show. that. :w-hen .the: temperatures. is: raisedzzup to this high point, the tendeney -foriironto chloridize is so great in respect to the chloridization of the iron at lower temperatures, that the selectivitytends to go outsidehtherdesired range. :Thus a. temperature.of .about 900. Fmmay.- be considered as About L the uppermost temperature .lilimit rat which the desired selectivityr-.in.accordance with the presenti inventionglis .attained.

"Example III .Zlihisexample is,given.:toi1lustrate the. eifectiof .ilariations. in .the totallamountiof HCl used zdurting the. chloridizing. reaction. In alltestsin this ,examplelfied Aroostook .ore oftheficomposition given-above and havingagrain size .of' minus. 150 rme'sh .was. usedinv the same rotary furnaceand generallytunder the conditions described. Ex- Sample I. man tests sunder this example, gas ,.was,.-passecl. through the furnace :at .the rate-of 10 cc: ofHz and 50;cc=.of: HCLboth per minute; and .in.,-all.-tests, .the solid material-was heldat 600 .F. iThetimeof the reactionswas varied in these aseweralptests, t-soxas to subject. the solid: material .tQKdifieringVtotaL. amounts of HCl.

:A. In this 3. test the .:stoichiometric amount of .HCl required toaconvert. all the manganese pres- ..entmto.Mn12 -washused. This: took place in 147 minutes. The -..resulting solid 'material, upon analysis, showed that 50.7 of the manganese presentphad been-converted to -MnClz and 3.5% sofuthe iron.present= had been converted to FeClz, g-ivingia ratio :of manganese to iron in the soluble ,prod-uct of. 6.10; 1.

B. this test 31109;, of the stoichiometric amount of Hcliwas passed through-"the fiurnace during a period of i62 minutes. .Therresifithig product showed, upon analysis that 55.9%:offthe manganese present had been converted tozMnGlz, while 8.2 "of' the iron presenti' had'cbeen won- 5 verted to FeClz, giving a: ratiooimanganese zto .iron in-the soluble product of 2.66:1.

C. Inthisitest 150% of Jtherstoichiometiic amount of HCl was used during a test peridd of 220::minutes. .The final:.product,' upon analysis,

been. converted to. MnClz and 10.2 ofiithedrnn present. had been converted to neon; giving. a 1: ratio softmanganesexto 'ironrimthe? solubleeportion of the final :productxof. 2i3'l 1.

Example IV This example "is merely to bring ouva comparison of "prior' tests, "illustrating" varying "gas compositions (as to 1-101) ancl'in'cludes wtestin which there wasa" low HCl concentration 'irrthe gas present (see Example II--A) "whereinpnly 100 cc; of'I-ICl waspresent in'ajtotahofififificc or 6.13%. On the-other hand," in -Example 'III, '-substantially-83.3%"of the total'gas'present was no1.

There is furthef-illustrat ed the eff ect of diluent gas in Example II-'-A, --wherein nitrogen =-represented about 93% of the total gas present.

Whi-1e there is herein-disclosed in=siibstantial detail all the-essentiahelements-of the: present *process and the ranges of -=equivalents where equivalents are'reasonably 'contempla-ted, it'-is intended that the presentinvention sh'a-ll'be considered to" include such reasonable equivalents as'will occur tothose' skilled'infthe art from= the foregoing disclosure.

"What is claimed is:

1. The process of selectively chloridi'zing manganese in the treatment -(immaterial-"containing 49 iron and manganese and in which the amount 'of' iron present 'is substantially greater thanthe "amount of manganese present; comp'risingthe steps of introducing said-'ma-terialinto reaction :zone, -maintaining said material =in= said -zone air-atemperature in the range of-about300 F. to about 900 F., 'passingHCl into'saidzone to contact said material= therein,-' supplying to saidzone 1 an -'-amount of hydrogenwuflicientso that the gases leaving-saidzzone contain at least 50 a trace of hydrogen, carrying on the steps aforesaid untih at least about 50 "ofthemanganese present has been" converted to -Mn'Cl2,"arid :dis-

continuing the processsteps aforesaidwhenthe ratio of "manganese chloride to ferrous chloride produced is at least 1: 1.

2."The process in accordance with "claim 1, 'wherein the- HCl concentrationin saidgases'is: at least about-6% by volume.

"3. -The process in accordance with claim :1, wherein said material is maintained in' said" zone at a temperature in therange of about400-'F3-to abOut SOO 'F.

4. The process in "accordance with "claim 1, :wherein said mater-iaL is I a "naturally occurring -ore, selected from "the group consisting "of tGeorgia ochre, and F Red and Blue -Aroo'stook :ores.

5. L'I'hexprocess of selectivelychlori'c lizing managanese in the'treatment of material containing 1 0 .rironiandi manganese and in which the amount of iron present is substantially greaterthan' the amount :of manganese :present, 'comprisingthe rstepssof introducing saiclmaterial into-areaction ":zone, maintaining=r said material Lin saictzone at 7 5 1a temperatureijn r the range of about 300 F$ to showed that 61.5%: of themanganesepresenthadabout 900 F1, passing HCl into said zone to contact said material therein, supplying to said zone an amount of hydrogen suflicient so that the gases leaving said zone contain at least a trace of hydrogen, and discontinuing the process aforesaid when the conversion of iron to ferrous chloride tends to give a final product wherein the ratio of ferrous chloride to manganese chloride is greater than about 1 :4.

6. The process of selectively chloridizing manganese in the treatment of material containing iron and manganese and in which the amount of iron present is substantially greater than the amount of manganese present, comprising the steps of introducing said material into a reaction zone, maintaining said material in said zone at a temperature in the range of about 300 F. to about 900 F., passing HCl into said zone to contact said material therein until the amount of HCl passed through said zone is substantially that amount required to convert all the manganese present in said material to MnClz, supplying to said zone an amount of hydrogen sufficient so that the gases leaving said zone contain at least a trace of hydrogen, and discontinuing the process steps aforesaid when the ratio of manganese chloride to ferrous chloride produced is at least 1:1.

7. The process according to claim 6, wherein said process is carried on with said material in said reaction zone at a temperature in the range of about 400 F. to about 800 F., and wherein said process is discontinued when the conversion of iron to FeClz tends to produce more FeClz in respect to the MnClz produced than about 1:4 by weight.

IRVING P. WHITEHOUSE.

MARION ERNEST GRAHAM.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,290,843 Kinney July 21, 1942 2,425,995 Christensen Aug. 19, 1947

Claims (1)

1. THE PROCESS OF SELECTIVELY CHLORIDIZING MANGANESE IN THE TREATMENT OF MATERIAL CONTAINING IRON AND MANGANESE AND IN WHICH THE AMOUNT OF IRON PRESENT IS SUBSTANTIALLY GREATER THAN THE AMOUNT OF MANGANESE PRESENT, COMPRISING THE STEPS OF INTRODUCING SAID MATERIAL INTO A REACTION ZONE, MAINTAINING SAID MATERIAL IN SAID ZONE AT A TEMPERATURE IN THE RANGE OF ABOUT 300* F. TO ABOUT 900* F., PASSING HCL INTO SAID ZONE TO CONTACT SAID MATERIAL THEREIN, SUPPLYING TO SAID ZONE AN AMOUNT OF HYDROGEN SUFFICIENT SO THAT THE GASES LEAVING SAID ZONE CONTAIN AT LEAST A TRACE OF HYDROGEN, CARRYING ON THE STEPS AFORESAID UNTIL AT LEAST ABOUT 50% OF THE MANGANESE PRESENT HAS BEEN CONVERTED TO MNCL2, AND DISCONTINUING THE PROCESS STEPS AFORESAID WHEN THE RATIO OF MANGANESE CHLORIDE TO FERROUS CHLORIDE PRODUCED IS AT LEAST 1:1.