US3903236A

US3903236A - Method for obtaining metal values by the halidation of a basic manganiferous ore with ferric chloride pre-treatment

Info

Publication number: US3903236A
Authority: US
Inventors: Hugh L Mccutcheon; William S Kane; Paul H Cardwell
Original assignee: Deepsea Ventures Inc
Current assignee: Deepsea Ventures Inc
Priority date: 1972-11-27
Filing date: 1972-11-27
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02

Abstract

This invention provides an improvement in the process of obtaining metal values from manganiferous iron-containing ore by halidating the ores and separating the metal values from the ore as the halides. This improvement comprises segregating the iron halide from the mixed halides and recycling the iron halide to react with the ore prior to halidating. This process is especially applicable to ocean floor nodule ores and utilizes preferably hydrogen halides or halogens as the halidating agents, in aqueous solutions.

Description

United States Patent [191 McCutcheon et al. Sept. 2, 1975 [54] METHOD FOR OBTAINING METAL 1,917,228 7/1933 Bacon et a] 423/46 VALUES BY THE HALIDATION or A BASIC ggg'ggg 2 1332 a s 3* MANGANIFEROUS ORE WITH FERRIC l0 1959 22; CHLORIDE PRE-TREATMENT 3,244,509 4/1966 Nowak et al... [75] Inventors: Hugh L. McCutcheon, Gloucester 1466-169 9/1969 Nowak et Point; William S- Kane, wiComico; 3,607,236 9/197] Brooks et a 75/1 12 X Paul H. Cardwell, Zanoni, all of Va.

[73] Assignee: Deepsea Ventures, Inc., Gloucester Primary Examiner-'05? vertiz p i v Assistant Examiner-Brtan E. Hearn Attorney, Agent, 0r Firm-Barry G. Magidoff [22] Filed: Nov. 27, 1972 [2]] Appl. No.: 309,949

[57] ABSTRACT 52 US. Cl. 423/3s; 423/385 423/49, This invention provides an improvement in the pm 423/51; 423/139; 423/140 423/150 75/l04 cess of obtaining metal values from manganiferous 75/1 iron-containing ore by halidating the ores and separat- [5 1] Colg 3/04; Colg 45/O6 C01g 49/06 ing the metal values from the ore as the halides. This Colg 5 Colg 53/08 improvement comprises segregating the iron halide [58] Field of Search 423/38-40, from the mixed halides and recycling the iron halide 423/46, 49, 150, 24, to react with the ore prior to halidating. This process 75/1 1 H23 1 104 is especially applicable to ocean floor nodule ores and utilizes preferably hydrogen halides or halogens as the [56] References C'ted halidating agents, in aqueous solutions.

UNITED STATES PATENTS 1,904,583 4/1933 Wescott 423/46 X 11 Claims, 1 Drawing Figure f'AflR/C #701- {51:75: gig 5; raw/new --""z M, I: lax/047m Af/(IIVIS "4' fill/ '1 AI/(Iil (vaulra /2w q, I l/fll/ID 2100/2: 000/0 W "2 M m W 21:12,, Z-IIMMFE imam/a: [JIM/V5! 0 M's/a0: t'ltZfMYJ/s flit/202ml: flll 'lmzysu AER/07a ,1

METHOD FOR OBTAINING METAL VALUES BY THE HALIDATION OF ABASIC MANGANIFEROUS ORE WITH FERRIC CHLORIDE PRE-TREATMENT since their creation. First, the nodules have never been exposed to temperatures other than those at the bottom of the ocean at the location at which they were formed. They have an extremely large surface area, often better It is not a common situation to obtain a relatively h 50 pergem porosity d the are thus relatively valuable nonferrous metal such as nickel, cobalt, cop- Chemically reactive ores per, manganese, t1tanium, 1nd1um and zinc, from ores The nodules are f d as an extremely complex which are prlmarlly Ores, n g a rela' crystalmatrix of iron and manganese oxides: tiny grains tlvely hlgh P p of Such Ores, Whlch have of each oxide of a size and type which are substantially been Obtained y Conventlonal mmmg, Include Py 1O impossible to separate with presently available physical and latel'ltic and Serpemme p m s- A relatwely means. These iron and manganese oxides form the pp Source hlgh'quallty mangamfemhs crystalline structure within which are held, by means however, is a matenal wh1ch is found on the ocean not precisely known, other meta] compounds, most floor and has m t0 be known as Ocean floor Q likely oxides, including those of nickel, copper and cobalt, as the.main ingredients followed by chromium, Withthe increased awareness on the part of both the vanadium many more elements mclud' public'and the metals industry of the ecological dangers mg the a metals Shver and gold that can arise from continued surface mining of miner- In addltloh to the Crystals of compounds 0f the l als and the increased problems of pollution caused by able metals h h f 815 also a qhahmy of the refining procedures required for most ores mined or gahghe matenal mhrhately admixed nodule from the land, industry has been interested for several Thls h ls Sand and a mclusies years now in the mining of minerals from the sea. This the usuhl Oxldes of Shlcoh and alummurh m VarYmg has been an extremely elusive target up to the present. proporhohs and some carbonates especlahy Calclum The directions taken have included both attempts to carbonates: wrest minerals directly from solution-insea water and The preclse Chemlcal F l l nodules 2:1 the mining of ores which are available on the floor of his .depehchhg h jz zhflf t e 6 the ocean. These ores do notrequire any digging into vanatlfm apharently ls g y 1 rences m or stripping of the earths crust; the ocean floor ores ature m vanous p aces I erehces 1h 99 13 O can merely be scooped up or in other ways removed s f Perhaps Caused by thegressure an rh g from the ocean floor without actually rending the Vanahohs at dlfferfaht h S and composmon 0 earflps surface 7 ad acent land areas; var1at1ons 1n the amount of oxygen which is present in the water in different locations and Ocean flOOl' nodules were first COllCt6d in the first perhaps other variables not readily apparent to bservhalf of the l870s. They have been studied by many. ers. Generally, however, in almost all cases the metals Workers in an attempt to determine th compositlon, which are present in primary proportions are mangaand after their Composition had n d l i 9 y nese and iron. The following table (taken from an artito decipher y to wrest fromfcheir Peculiar F cle entitled The Geochemistry of Manganese Nodules the valuable metals contained therein. It is presently and A o iated De osits from the Pacific and Indian believed that these nodules are actually creations of the Oceans by Croonan and Tooms in Deep Sea Research sea; they are somehow grown from the metal corn- (1969), Volume 16, pages 335-359, Pergarnon Press pounds which are dissolved in sea water, generally in (Great Britain) shows the relative compositions of the the form of the metal oxides. most valuable metals'contained in nodules taken from The metal valuesin the nodules are almost excludifferent areas within the Pacific and Indian Oceans.

TABLE I Mn 13.96 15.87 15.71 l 15.85 22.33 19.81 16.61 13.56 15.83 Fe 13.10 13.30 9.06 12.22 9.44 10.20 13.92 15.75 11.31 Ni 0.393 0.564 0.956 0.348 1 1.080 0.961 0.433 1 0.322 0.512 CO 1.127 0.395 0.213 0.514 0.192 0.164 0.595 0.358 0.153 Cu 0.051 0.393 0.711 0.077 0.627 0.311 0.185 0.102 0.330 Pb 0.174 0.034 0.049 0.085 0.028 0.030 0.073 0.061 0.034 Ba 0.274 0.152 0.155 0.306 0.381 0.145 0.230 0.146 0.155 Mo 0.042 0.037 0.041 0.040 0.047 0.037 0.035 0.029 0.031 v 0.054 0.044 0.036 0.055 0.041 0.031 0.050 0.051 0.040 Cr 0.0011 0.0007 0.0012 0.0051 0.0007 0.0005 0.0007 0.0020 0.0009 Ti 0.773 0.810 0.561 0.489 0.425 0.467 1.007 0.820 0.582 L.O.l. 30.87 25.50 22.12 24.78 24.75 27.21 i 28.73 25.89 27.18

Depth J (m) 1757 5001 5049 1146 4537 4324 3539. 3793 5046 l. Mid-Pacific Mountains (5 samples) 5. Northeast Pacific (10 samples) 2. West Pacific (23 samples) 6. Southeast Pacific (8 samples) 3. Central Pacific (9 samples) a 7. South Pacific (11 samples) 4. Southern Borderland Seamount Province (5 samples) 8. West Indian Ocean 10 samples) 1 9. East Indian Ocean (14 samples) sively in the form of the oxides and moreover are pre s- Nodules are also found in the Atlantic ocean; howent in avery peculiar physical configuration. The physiever, it has been found that generally these nodules cal and chemical structure of the nodulesare believed to be a direct result of the conditions under which they were created and to which they have been exposed contain lower proportions of the more valuable metals and correspondingly higher proportions of the less desirable metals which cannot be readily refined and which have'little or no value; such as the alkaline earth M metals.

Because of the peculiar and intricatecrystal structure of the ocean floor nodules, the common refining techniques used for the refining of land ores are not generally suitable for the nodules. The art has struggled with various schemes for refining these nodules but only recently has a process been devised which permits the commercial refining of these nodules to obtain economically significant quantities of the valuable metals contained therein in the necessary degree of purity.

The one especially promising procedure for the nodule ore includes the halidation of the ore to convert the desired metal values to the corresponding watersoluble metal halides, and then separation of the halides, by a variety of means, from the ore. The individual metal values can then be further separated to obtain relatively pure compounds of each metal value present. The halidation can be carried out utilizing an acid substance, such as a hydrogen halide (either in aqueous solution or in the vapor state) or an elemental halogen,

again either in an aqueous solution or in the vapor state, and preferably in an anhydrous state.

Iron-nickel ores, e.g. of the lateritic or serpentine type, which contain only a minor proportion of manganes'e, have also been refined beginning with a chloridizing procedure, using a mixture of HCl and water vapor to selectively from chlorides of nickel and cobalt to the exclusion of iron and chromium. The nickel and cobalt chlorides are then leached out using water. (See U.S. Pat. No. 2,766,115 to Graham et al.).

Other chloridizing processes have found some use with pyrites cinders, using various sources for the chlorine, including metal salts, such as CaCl and NaCl, as well as HCl and C1 These processes have been carried out at' vaporizing temperatures for the metal chlorides as well as at lower temperatures. High temperature chloridizing processes, wherein the metal chlorides are volatilized, have been used in the refining of manganiferous iron ore, utilizing NaCl or CaCl as the reagent. In this case the ore contains manganous and ferrous materials, which are not reduced.

In the recently developed process for refining the ocean floor nodule ores utilizing a halidation agent, the ocean floor nodule ore is reacted with either a halogen 'or a hydrogen halide to form mixtures of the corresponding halides of iron (ferric), manganese (manganous), copper, nickel and cobalt, and a large number of other metal halides in extremely small concentrations.

When further refining mixtures of metal halides, (such as are obtained from the halidation of ocean floor nodule ore) an aqueous solution of the mixed halides is often formed. Such a solution contains not only the desirable and most valuable nickel, copper, cobalt and manganese halides, but also the rather less valuable, and generally burdensome, ferric halide. It is, therefore, necessary to separate the halides and especially to remove the less desirable ferric halide, often present in large proportions.

One of the recently developed general procedures for refining the ocean floor nodule ore, includes reacting the nodule ore with a halidating agent, such as an elemental halogen or a hydrogen halide, e.g., C1 or HCl, to form a reaction mass comprising the water-soluble halides of divalent manganese, copper, nickel, cobalt and iron. The manganese present in the ore is primarily .dium, e.g. where the hydrogen halide is added as an aqueous 'solution. Alternatively, the reaction can be carried out in an anhydrous condition, i.e. utilizing either hydrogen halide vapor or elemental halogen, and" the reaction product then leached out utilizing an aqueous leaching liquid to remove the water-soluble halide salts out of the ore and separating the leach solution from the insoluble gangue or detritus of the ore.

. Iron-containing ores, which are treated according to the above processes comprise oxygen-containing metal compounds, such as the oxides, hydroxides and carbonates, which can be considered basic, and which are reactive towards halidation reagents, which can be considered acidic, to form metal halides. The basic constituents of the ores include the compounds of metals which are the desired, valuable products from this process, such as nickel oxide and copper oxide, as well as undesirable impurities in the ore, such ascalcium carbonate.

The iron halide was separated from the more valuable metal halides before' they were purified. The iron values which had been removed from the solution were generally discarded as it was not profitable to prepare iron or steel by this procedure.

There was, therefore, an additional cost in the process for the amount of halide source used up in the halidation of the iron values present, which was an undesirable side reaction, because iron was not a desired product. In addition to the loss of the halidation reagent in the halidation of the iron, there was the loss of halidation reagent by reaction with other'undesirable constituents which are present in the ore, such as calcium carbonate. Many halidation reagents are relatively expensive materials and the result of the two-fold loss caused by reaction with the iron values and with the undesirable basic compounds, generally present in the ore, renders these procedures less economical. The particular objective of the present invention is to provide a major saving in the halidation reagent utilized by recycling a portion of the halide value (in the form of an iron halide) to contact the ore prior to halidation under conditions in which the ferric'halide reacts with the basic constituents in the ore. This procedure eliminates at least one of the major losses of halidating agent when treating an ore which contains a high proportion of iron values, and, therefore, decreases the cost of the halidation substantially. V

In accordance with the present invention, the relatively costly halidation reagent, i.e. an elemental halogen or a hydrogen halide, is conserved by pre-treating an ore with ferric haliderecycled from the refining operation so as to react at least partially with the basic constituents present in the ore containing a substantial proportion of iron value. The improvement of this process comprises segregating iron halide from a mixture of metal halides obtained by halidating an ironcontaining ore, and recycling the iron halide to contact the ore prior to halidation under conditions in which the iron halide reacts with basic constituents present in the ore prior to the halidation, resulting in a substantial net decrease in the amount of halidating agent required. I i

The reaction of the ferric halide with the other undesirable basic components of the ore generally believed to comprise principally calcium carbonate results in theformation of ferric oxide plus the corresponding halide of, e.g. calcium. The ferric oxide formed fromthis reaction must be separated from the ore; it should not be permitted to be carried into the halidation reactor where it would react again with the halidating reagent and thus short-circuit the intent of the present invention.

If the, ferric halide is in an aqueous solution when it is contacted with the ore, the ferric oxide which forms, precipitates. The precipitate can be readily separated from the ore by conventional procedures, for example, by conventional flotation processes or in a hydroclassifier.

The segregation of the iron halide, i.e. ferric halide, is preferably made from an aqueous solution of the mixture of metal halides. The ferric halide is extracted utilizing an extractant which is selective to remove ferric halide from an aqueous solution containing the other metal halides formed during the halidation of the ore and from which the ferric halide can be readily stripped. Preferably, the extractant is a liquid, which is optimally immiscible with water and which selectively extracts ferric halide from a mixture of other metal halides present in the solution. It should be pointed out at this time that the extraction is of the complete ferric halide compound. This is not an ion exchange situation where the metal ion is chelated or complexed with the chelating agentand the halide ion remains behind. It is necessaryin carrying out this procedure that the halide value be removed together with the iron value into the extractant. i e

The extracting medium is preferably immiscible with water to improve the economic efficiency of the process. If the extracting medium were not immiscible with water, a substantial loss of the extracting reagent would occur during each extraction, by virtue of at least a partial solubility in the water phase and a loss of the extracting agent in the aqueous raffinate.

Extracting agents which are especially suitable because they are highly specific to ferric halides in the mixed halide solutions which are obtained, e.g. from ocean floor nodule ores, include, for example, certain organic amines and organic phosphate esters. These organic phosphate esters and organic amines are specific for the extraction of ferric halides from an aqueous solution comprising ferric halides, copper halides, nickel halides, cobalt halides and manganese halides. These organic amine and organic phosphate ester materials are preferably used in solution in solvents which are immiscible with water.

The organic phosphate esters which can be used for preferentially extracting iron halide include preferably the trialkylphosphates. Such materials have the general formula:

wherein the R groups may be the same or different organic groups, especially hydrocarbon groups and, are optimally alkyl groups, containing from 1 to about 10 carbon atoms, preferably from 2 to 8 and optimally 3 to 6 carbon atoms.

Examples of such materials include tri-n-butyl phosphate, tri-n-hexyl phosphate, n-butyl-di-n-hexyl phosphate, n-propyl-di-n-butyl phosphate, tri-n-propyl phosphate and triamyl phosphate. Esters containing aromatic and cycloaliphatic groups would also be useful in this invention and include triphenyl phosphate, phenyl di( 2-ethylhexyl) phosphate and tri(cyclohexyl) phosphate. Tri(n-alkyl) phosphates are most preferred.

The amines which can be used for preferentially extracting iron halide include the primary, secondary, tertiary and quaternary amines. Preferably the amines are aliphatic amines wherein each aliphatic group has from 1 to about 30 carbon atoms; preferably the total number of carbon atoms in the molecule is at least about 12 carbon atoms. Examples of the useful amine extractants include primary aliphatic amines having the formula, R-NH wherein R is preferably a tertiary alkyl group having the formula wherein R contains from about 9 to about 30 and preferably from about 18 to about 24 carbon atoms, and R and R contain from 1 to about 4 carbon atoms, and preferably are methyl groups. Examples of such compounds include N-trialkylmethylamines such as N-( 1,1- dimethyleicosyl) amine and N-( l ,l-dimethyldocosyl) amine.

Preferred secondary amines include compounds having the formula:

wherein R, R and Rf are defined as above and R is preferably an alkyl group containing from 1 to about 20 carbon atoms. An example of such a preferred second ary amine is N- l auryl-N-( l,l-dimethyleicosyl) amine.

Preferred teriary amines have the formula:

wherein R, R" and R are alkyl groups, preferably normal alkyl groups each containing from about 5 to about 15 carbon atoms and optimally from about 8 to about 10 carbon atoms; preferred such compounds include tri-(n-octyl)amine, di(n-octyl)-n-hexyl amine, di( n-hexyl -n-octylamine, di( n-octyl n-decyl )amine, di( n-decyl)(n-octyl )amine and tri(n-decyl)amine.

Quaternary ammonium compounds can also be utilized as extractants and the preferred such ammonium groups can empirically be defined by the following equation:

wherein R and c are as defined above and R is hydrogen or a lower alkyl group containing from 1 to about 4 carbon atoms. Quaternary ammonium groups can be added in the form of any salt, i.e. combined with any anion which is substantially inert in or will not detrimentally interfere with, the process of the present invention. Preferably, the quaternary compound is in the form of a halide and optimally the same halide as is present in the aqueous solution to be extracted. Examples of such preferred quaternary ammonium compounds include tri(n-decyl) methyl ammonium chlo-- ride and tri( mixed n-C alkyl) methyl ammonium chloride, the latter being derived from a mixture of C CQ, normal paraffinic hydrocarbons. The above organic amines and organic phosphate esters are compounds generally known to industry and commercially available. Any other amines, esters or other compounds useful as selective extractants for ferric halides in the aqueous systems obtained from the halidation of ironcontaining ores can also be used in the process of this invention.

As explained above, the extracting agent is preferaaqueous raffinate. If it is desired, however, more concentrated solutions can be utilized and even substantially pure amines or phosphate esters can be used. Mixtures of extractants can be used as long as they are not jointly reactive and do not interfere with the process of this invention.

Such diluents include generally any inert hydrocarbons which are solvents for the extracting agent, per se, and for the ferric halide-extracting agent complex, and which do not react with any of the other materials present under the conditions of the extraction process. Generally, liquid aliphatic, cycloaliphatic, aromatic, cycloaliphatic-aromatic, aliphatic-aromatic or chlorinated such hydrocarbons are preferably utilized as the diluent-solvents for the ferric halide extracting medium. Optimally, the solvent-diluent has specific gravi ties in the range of from about 0.65 to about 0.95 and a mid-boiling point in the range of from about 120 to 615F. (ASTM distillation.) However, substantially any liquid can be used as a solvent-diluent that meets the 2. A solvent for the extracting agent-iron halide complex; I

3. immiscible with water; and

4. Readily separable from water.

The concentration of the extracting agent in the solvent diluent is determined not only by the solubility of the extracting agent per se, but also by the solubility of the extracting agent-ferric halide complex. Examples of suitable diluents include benzene, toluene, xylene, aliphatic and aromatic petroleum fractions such as naphtha and derivatives thereof and mixtures of the foregoing. In addition to the aliphatic, aromatic, cycloaliphatic-aromatic, aliphatic-aromatic hydrocarbons and cycloaliphatic hydrocarbons, chlorinated such hydrocarbon liquids can also be usefully utilized.

Light fuel oil, high flash point kerosene and other petroleum hydrocarbons, such as hexaneheptane mix-,

tures are preferred. Generally, the aliphatic materials are most preferred because of their ready'availability and ease of separation from the aqueous phase.

In addition to the diluent and the extracting agent,

hol, 2-ethylhexyl alcohol, cyclohexanol and mixtures of these and other alcohols. Decanol is a preferred material. a

Generally no more than the necessary amount of the phase modifier e.g. alcohol, which is necessary to inhibit the formation of the emulsionor prevent entrainment, should be used. Usually no more than about25 percent by volume of .the:phase modifier is necessary. Preferably, from about 2-to about 10 percent by volurne is satisfactory andnot more than about 5 percent is most preferred. The phase modifier canbe completely eliminated if desired and, therefore, is optional in the present procedure.

The present invention does not comprise solely the selection of the extracting medium. It is preferredthat the extracting medium be a liquid, because liquidliquid extraction of a normally solid material from solu tion is a relatively simple and common procedure. However, other extraction procedures can be followed and other types of extractants used.

When utilizing liquid-liquid extraction from an aqueous solution of mixed metal halides, a wide range of aqueous phase-to-aqueous-immiscible-phase volume;

ratio can be utilized in the present invention. Generally, using a 20 percent by wt. solution of the amine or phosphate ester, aqueous-immiscible/aqueous phase volume ratios of from about 1:1 to about 5:1 are desir- Temperature is usually not critical to the extraction and generally ambient temperatures can be utilized; preferably, of course, the temperatures should be such as to maintain the aqueous solutions and the extracting medium in the liquid phase under ambient pressure and to maintain the halides and the complex with ferric halide in solution.

The pH of the aqueous solution from which the ferric halide is extracted is preferably not greaterthan about 2.3 and optimally not greater than about 2.0. The critical point is that at which the ferric halide is hydrolyzed to form iron oxide or iron hydroxide which precipitates out of solution. Accordingly, the pH of the aqueous solution should be not greater than that required to maintain the ferric halide in solution.

The extraction medium must be selected so that it is selective for ferric halide in the particular solution to be extracted based upon the composition of the other metal halides present. That is, the aqueous solution to be treated with the extracting medium in accordance with this invention should contain sufficient iron halide to be extractable utilizing the extraction medium se lected, and the extraction medium should not extract other materials present, e.g. manganese, cobalt, nickel and copper halides.

Utilizing the amine or phosphate ester ferric halide extractants defined above, the aqueous solution can be substantially saturated in each of the various metal ha lides commonly associated with iron in the ocean floor nodule ore, i.e., nickel, cobalt, copper and manganese. However, if other extractants are utilized which perhaps are more sensitive to concentration in the concentration range of the aqueous solution, the composition must be adjusted accordingly, either by diluting with additional water or by concentrating, as by evaporation.

The ferric halide removed from the aqueous solution is recycled to the ore. Preferably, this is accomplished after stripping the iron halide from the extractant, and most preferably the ferric halide is in aqueous solution when it is recycled and contacted with the ore.

When a liquid-liquid extraction scheme is utilized,

the ferric halide is stripped from the water-immiscible extraction medium by water; preferably, the water is sufficiently acid to prevent the hydrolysis of the ferric halide, and generally a pH of not greater than about 2.3 is maintained. Although the pH can be maintained utilizing any acid, preferably, however, a hydrogen halide acid is preferred; however, other acid anions which are non-interfering with the process of the present invention can also be present and, therefore, materials such as sulfuric acid, nitric acid, etc. can be utilized.

The volume phase ratio of an aqueous stripping liquid to the water-immiscible extraction medium is preferably in the range of from about 1 to 5 to about 1 to 1; however, the best results are obtained when a ratio of stripping liquid to extract phase of at least about 1:4 to about 1:1 is maintained.

When the ferric halide is recycled to the ore in an aqueous solution, the solution generally can contain from about 5 to about 75 g/l iron, preferably from about 20 to about 60 g/l iron and optimally from about 35 to about 50 g/liter iron.

Both the extraction of the ferric halide from the aqueous solution of mixed metal halides and the stripping of ferric halide from the water-immiscible extraction medium can be carried out utilizing any conventional contact apparatus. The material can be carried out in a single-stage batch basis or in a continuous flow unit; preferably, in a continuous unit the flow of the two phases is counter-current, such as in a continuous, counter-current mixer-settler unit. The number of stages can be yaried as required based on the efficiency of extraction and stripping of the specific materials being treated and of the apparatus being utilized. By adjusting the relative volumes of the aqueous mixed metal halide solution and of the water-immiscible extraction medium, it is possible to obtain a substantially complete removal of ferric halide from the aqueous solution into the organic medium. Similarly by adjusting the ratio of the extraction medium to the aqueous stripping liquid, substantially complete removal of the ferric halide from the extraction medium can be obtained. If there is any residual ferric halide remaining in the extraction medium, it can be recycled together with the extraction medium for further extraction use without interfering with the process of the present invention. Indeed, it is generally assumed that in continuous operation, the extraction medium is stripped and returned for further use to the extraction step with a gradual buildup of ferric halide until an equilibrium level is reached.

Useful apparatus, in addition to mixer-settler units, include for example, packed and plate-type towers, baffled towers and pulse columns, generally also operated counter-currently.

In a preferred procedure, in accordance with the present invention, a basic ore such as for example, an ocean floor nodule ore as described above, containing a substantial proportion of iron values plus other more valuable nonferrous metals which it is desired to extract, is reacted with an aqueous solution of a hydrogen halide.

The ore is preferably comminuted to a particle size of not larger than about 35 mesh. The comminuted ore is contacted with the aqueous hydrogen halide solution under conditions of temperature and pressure at which the solution remains a liquid. It has been found that temperature is not critical to this reaction and thus ambient conditions are preferred. However, if desired higher or lower temperatures can be used. Generally, temperatures in the range of from about 0 to about C should be used.

The aqueous leach solution leaving the reactor has a pH of not greater than about 2 to avoid precipitation of iron oxide; this solution comprises the halides of iron, copper, cobalt, nickel and manganese.

The reaction with the aqueous hydrogen halide solution proceeds with substantially any concentration of the hydrogen halide. However, to avoid having to handle excessive amounts of water, solutions of less than 1 percent by weight hydrogen halide should not be used. Preferably, a concentration of hydrogen halide of at leat 10 percent by weight hydrogen halide is used. Optimally a saturated solution is used, e.g. 36 percent by weight HCl, with additional hydrogen halide vapor bubbled in during reaction. The ferric halide is then extracted, utilizing the procedure in accordance with the present invention: first, extracting the ferric halide from the aqueous solution with a preferably liquid water-immiscible extraction medium, which can then readily be separated from the aqueous leach liquid. The extraction medium is then stripped preferably by using water having a pH not greater than about 2, and the aqueous stripping solution containing the ferric halideis then recycled and contacted with the nodule ore prior to halidation with the hydrogen halide solution. This contact removes some of the basic undesirable materials which are present in the nodule ore, generally considered to be calcium carbonate thus decreasing the quantity of hydrogen halide required to react in the ore halidation step. i

The effect of the procedure of the present invention in substantially eliminating the loss of the hydrogen halide value in the iron halide can be summarized by the following equations, using CaCO as an example of the basic undesirable material present in the ore.

Thus the net effect of this reaction is to cancel out the loss of hydrogen halide by reaction with the iron values in the ore. In most situations, where the basic undesirable material content of the ore is greater than the proportion of iron present, substantially all of the hydrogen halide which is utilized in forming the ferric halide is recycled, and made use of in neutralizing the basic undesirable material, and the only loss of hydrogen halide is in the excess basic undesirable material not neutralized. When the proportion of calcium carbonate is less than that of the iron values, there is still a net gain in the hydrogen halide value, because the loss to the carbonate is cancelled out. In all cases, the iron oxide formed during the pretreatment of the ore with the ferric halide, must be separated from the ore and removed before the ore is halidated, to prevent buildup of the iron in the process. The Fe O collected can be reduced to iron.

In lieu of reacting the nodule ore with an aqueous solution of a hydrogen halide, the ore can be reacted with to pretreat the ore. Elemental halogen reacts with the ore in much the same manner as the hydrogen halides; the only difference being that if the ore is not treated with a reducing agent before the reaction with the halogen, a smaller proportion of the manganese is reacted.

The aqueous raffinate from the extraction of the ferric halide, containing the mixed halides of copper, cobalt, nickel and manganese, can be then separated into individual metal values using a variety of procedures. In a preferred procedure, a liquid ion exchange process is carried out, wherein each of the metal values is consecutively extracted utilizing a liquid ion exchange medium. Such procedures are set forth in German patent specification P2,l26,l75.624 filed on May 26, 1971 and in P2,l52,696.5 filed on Oct. 22, 1971. Preferred liquid ion exchange extractants include the substituted 8-hydroxyquinolines, a-hydroxy oximes and naphthenic acids.

The 8-hydroxyquinoline compounds, which are especially useful for the separation of the metal halides in accordance with the present process, can generally be defined by the following formula:

i 6 5 R I. R

wherein each of the R groups can be hydrogen or a hydrocarbyl group or inertly-substituted hydrocarbon groups, such as alkenyl, alkyl, alkynyl, cycloalkyl, cycloalkenyl, aryl or combinations thereof, such as alkaryl, aralkyl, aralkenyl, alkyl-cycloalkyl, etc.

At least one of the R groups, however, must be a hy.- drocarbon group. Any inert substituent can be present, as long as it does not adversely affect the solubility of the substituted 8-hydroxyquinolines in organic solvents nor adversely affect the solubility in the organic solvent of the metal chelate formed therefrom.

The resulting metal chelate must remain soluble at least to the extent of approximately 2 percent by weight in the organic solvent,

The preferred position of the hydrocarbyl substituent of the 8-hydroxyquinoline nuclear structure is such as to preferentially complex with the desired metal ion in the aqueous solution. The sum of the carbon atoms in the R groups must be at least about 8 and can be high as 24 or more. The preferred R groups are alkylbenzyl groups or beta-alkenyl groups containing from 12 to 18 carbon atoms, preferably attached at the R R or R position. The optimum position for substitution is at the R position to obtain the highest degree of efficiency. For a more complete description of these hydrocarbylsubstituted 8-hydroxyquinolines, see Republic of South Africa specification No. 69/4397 to Budde Jr. et al., assigned to Ashland Oil, Inc.

Representative compounds useful for ion exchange and within the scope of the above general formula I are: 7-octyl-benzyl-8-hydroxyquinoline, 7-dodecyl-benzyl- 8-hydroxyquinoline, 7-nonylbenzyl-8- hydroxyquinoline, 7-ditertiarybutyl-benzyl'8- hydroxyquinoline, 7-hexadecenyl-8-hydroxyquinoline, 7'-dibenzyl-8-hydroxyquinoline, 7- dimethyldicyclopentadienyl-8-hydroxyquinoline, 7- dicyclopentadienyl-8-hydroxyquinoline, 7- dodecylphenyl-8-hydroxyquinoline, 7- phenyldodecenyl-S-hydroxyquinoline, and the lilge where one or more of the hydrocarbyl groups R are attached to ring carbon atoms in the 2nd, 3rd, 4th, 5th and 6th positions. Mixtures of these. 8- hydroxyquinoline derivatives can be used if desired.

The second preferred type of metal extractants are the alphahydroxy oximes, which are disclosed inter alia in U.S. Pat. Nos. 3,224,873; 3,276,863 and 3,479,378.

- These materials have the general formula:

wherein the R, R" and R groups can be any of a variety of organic, hydrocarbon radicals such as aliphatic and alkyl aryl radicals. R" can also be hydrogen. Preferably R and R" are unsaturated hydrocarbon or branched chain alkyl groups containing from about 6 to about 20 carbon atoms. R and R are also preferably the same, and when alkyl are preferably linked to the central carbon atoms by a secondary carbon atom. R is preferably hydrogen or unsaturated hydrocarbon or branched chain alkyl group containing from about 6 to about 20 carbon atoms. The oxime preferably contains a total of from about 14 to about 40 carbon atoms. Useful R, R and R" groups include in addition to hydrogen, the monoand. poly-unsaturated groups such as heptenyl, octenyl, decenyl, octadecenyl, octadecynyl, and 2ethyl-octadecenyl.

Alkyl groups include 2-ethylhexyl, 2,3-diethylheptyl, 2-butyldecyl, Z-butylhexadecyl, 2,4-ethylbutyldodecyl, 4-butylcyclohexyl, and the like. Examples of the preferred alpha hydroxy oximes include l9-hydroxyhexatriaconta-9, 27-dienl S-oxime; 5,1 O-diethyl-8- hydroxytetradecan-7-oxime; 5,8-diethyl-7-hydroxydodecane-6-oxime.

These alpha-hydroxy oximes and 8- hydroxyquinolines are also generally dissolved in an organic, water-immiscible solvent, in which they should be soluble to an extent of at least about 2 percent by weight. The useful solventsare set forth above for use with the extracting medium for the ferric halides. The alpha-hydroxy oximes or the 8-hydroxyquinolines can be present in the solvent in amounts of from about 2 to 50 percent by weight, based on the total solution, but preferably in amounts of from about 2 to about 15 percent by weight.

Generally, a phase modifier, such as is also used with the ferric halide extracting agents, is also used for oz-hydroxyoxime or 8-hydroxyquinoline solutions.

These liquid ion exchange media, which are used for the extraction of copper, cobalt and nickel values are generally chelates and thus remove only the metal val ues from the solution, leaving behind the anions.

The drawing shows a flow sheet for a process in accordance with the present invention wherein the nodule ore is halidated with an aqueous hydrogen halide solution.

The nodule ore obtained from the ocean floor generally is comminuted, e.g-nby crushing. The comminuted ore is then pretreated with an aqueous solution of FeCl to react with part of the basic substances that are present and passed to the halidation reaction stage.

The halidation reactor is preferably a multi-stage reactor system, wherein the nodules are passed countercurrently to the hydrogen halide solution, and the chlorine by-product is vented from each stage. Additionally, hydrogen halide vapor, exemplified by HCl, is shown being bubbled into the aqueous solution during halidation. The aqueous leach solution leaving the final reactorstage has a pH of not greater than about 2, to avoid precipitation of metallic compounds, and usually of from about 1 to about 2.

The final aqueous reaction liquid, containing the dissolved halides of manganese, iron, cobalt, nickel and copper, is then passed to a liquid extraction system to remove the iron by counter-current extraction with an organic solution of a trialkyl phosphate or an amine. The ferric chloride is extracted from the leach liquid, stripped from the organic extract phase with water, the organic extraction solution is recycled for further use and the aqueous FeCl solution is passed to the pretreatment stage for the nodules as described above. The iron-free aqueous raffinate is then passed to a liquid ion exchange separation system, to separate the copper value from the nickel, cobalt and manganese EXAMPLE Ocean floor nodule ore was obtained having the composition:

Components Percent by Weight Manganese 20 Iron 6.5

Nickel .88 Copper 0.55 Cobalt 0.12 Other Metals Minor The ore was ground to an average particle size of less than 35 mesh. The ground ore was prereacted with an aqueous FeCl solution containing 50 g/l iron as shown in the drawing and the ore was treated in a hydroclassifier to remove iron oxide from the ore. The underfiow was then passed through a five-stage leaching-reactor system, countercurrently to an aqueous solution of hydrogen chloride, fed at an initial concentration of hydrogen ion of 11 N. The overflow solution from the final stage, which comprised an aqueous leach solution of manganese chloride, ferric chloride, cobalt chloride, nickel chloride and copper chloride having a pH of l to 2 was next treated to remove iron chloride from the solution.

The leach solution, having a pH of 2 was passed through 4 mixer-settler stages, countercurrent to an organic solution comprising 20 percent by volume N- lauryl-N-( l,l-dimethyleicosyl)-amine, i.e. having the formula 20 percent by volume isodecanol and the remainder a kerosene diluent, at an aqueous-to-organic ratio of 1:4 by volume.

The organic extract, containing FeCl was stripped with water, having a pH of 2 in a countercurrent, threestage mixer-settler system at an organic-to-aqueous ratio of 4:1 by volume. The aqueous stripping solution of FeCl:, was then passed to the FeCl pre-reactor.

The aqueous raffinate from the ferric chloride extraction contained manganese chloride, copper chloride, nickel chloride and cobalt chloride in solution. This material was extracted utilizing a solution comprising 10 percent by volume of an alphahydroxyoxime (5,8-diethyl-7-hydroxy dodecane-6- oxime, known as LlX-64N), 20 percent by volume isodecanol, and the balance a mixed hydrocarbon solvent, comprising mixed aromaticaliphatic petroleum hydrocarbons having a boiling point range of 4lO-460F and a specific gravity of 0.81. The aqueous raffinate had its pH adjusted to about 2. The pH was maintained at about 2 by the addition of caustic during the extraction of copper. The aqueous raffinate and organic extractant passed countercurrently through five mixer-settler stages at an organic-to-aqueous ratio of 6:3 1.5 by volume. The aqueous raffinate from the copper extraction contained substantially all of the maganese, nickel and cobalt originally present but substantially all of the copper had been extracted.

Following the separation from the final settling stage, the organic extract was stripped of copper by spent acid solution from a copper aqueous electrolysis cell having a hydrogen ion concentration of 3N, utilizing countercurrent flow through five stages of a mixersettler series.

The aqueous raffinate from the copper extraction step was adjusted to a pH of about 4.5 by the addition of 2N caustic solution. The resulting aqueous solution was extracted in a five-stage mixer-settler system, with a solution of 10 percent by volume 7-(3-(5,5,7,7,- tetramethyl-l-octenyl))-8-hydroxyquinoline plus percent by volume isodecanol in kerosene to extract nickel and cobalt.

The nickel was stripped from the organic extract phase using the spent solution from a nickel electrolysis cell to which hydrochloric acid was added to a concentration of hydrogen ion of 3N in order to insure stripping of all of the nickel. The organic liquid and stripping acid were passed countercurrently through three mixer-settler stages at an organic-to-aqueous liquid ratio of 3:1, by volume. Substantially all of the nickel was removed from the organic phase.

The cobalt was next stripped from organic extract phase utilizing an aqueous solution containing 20 percent by wt. HCl, in four mixer-settler stages at an organic aqueous ratio of 3:1. The cobalt was extracted from the 20 percent HCl solution using a kerosene solution containing 10 percent by volume triisooctyl amine (TlOA), in three mixer-settler stages at an organic:aqueous volume ratio of 2:1. The cobalt was stripped from the TlOA solution utilizing spent aqueous electrolyte from a cobalt electrolysis cell in three mixer-settler stages with a 1:2 organiczaqueous phase ratio.

The raffinate from the cobalt extraction contained primarily manganese chloride. Hydrogen sulfide was passed through the raffinate to precipitate the various other metal values present, leaving a substantially pure solution of manganese chloride.

There were thus obtained, as a result of this process, four separate final streams each containing substantially pure metal chloride: copper chloride, nickel chloride, cobalt chloride and manganese chloride. Each of these aqueous solutions could be further treated by known methods to reduce the salts to the respective elemental metal.

Manganese is preferentially reduced in a fused salt electrolytic cell or in an aluminum reduction cell. The copper, nickel and cobalt are preferably electrolyzed in aqueous electrolytic cells.

We claim:

1. A process for refining a manganese oxide ore, the ore comprising as primary components the oxides of manganese and iron, and further comprising a basic constituent which includes at least one other nonferrous metal value, the process comprising:

pre-treating the ore with an aqueous pretreatment solution of ferric halide to form a solution of the halides of the basic constituents of the ore and solid ferric oxide;

separating the pre-treated ore from the resulting aqueous solution and solid ferric oxide;

halidating the pre-treated ore with an aqueous solution of a hydrogen halide to form a pregnant aqueous solution comprising dissolved ferric halide, manganese halide and a nonferrous metal halide;

separating the pregnant aqueous solution from the insoluble solids;

extracting selectively ferric halide from the pregnant aqueous solution with an extractant selective for the ferric halide and selected from the group consisting of organic amines and organic phosphate esters, to form an aqueous raffinate comprising the' manganese halide and the nonferrous metal halide but substantially free from ferric halide, and Stripping the ferric halide from the extractant to form an aqueous solution comprising the ferric halide; and

cycling the aqueous solution of the ferric halide to pre-treat the manganese oxide ore, prior to halidation with the hydrogen halide. 2. The process of claim 1, wherein the halidation reagent is a hydrogen halide selected from the group consisting of hydrogen bromide and hydrogen chloride.

3. The process of claim 1, wherein the halidation agent is hydrogen chloride.

4. The process of claim 1, wherein the aqueous pretreatment solution has a concentration of ferric halide in the range of from about 5 to about g/l iron.

5. A process for refining ocean floor nodule ore, the ore comprising as primary components the oxides of manganese and of iron and as secondary components compounds of copper, cobalt and nickel and further comprising basic constituents, the process comprising: pre-treating the ore with an aqueous solution of ferric halide to form a solution of the halides of the basic constituents of the ore and solid ferric oxide;

halidating the pre-treated ore with an aqueous halidating solution of a hydrogen halide to form a pregnant aqueous solution, comprising dissolved manganese halide, ferric halide, cobalt halide, copper halide and nickel halide;

separating the pregnant solution from the insoluble residue;

extracting selectively the ferric halide from the pregnant aqueous solution by a process comprising contacting the pregnant aqueous solution of the metal halides with a liquid extraction medium immiscible with the pregnant aqueous solution and selective for the extraction of ferric halide and comprising an organic solvent and an extraction agent selected from the group consisting of organic amines and organic phosphate esters to form a ferric halide extract and an aqueous raffinate comprising the manganese halide, cobalt halide, copper halide and nickel halide but substantially free from ferric halide, and stripping the extract with water to remove the ferric halide therefrom and to form an aqueous solution of ferric halide;and

cycling the ferric halide aqueous solution for pretreating the ore.

6. The process of claim 5, wherein the hydrogen halide is hydrogen chloride.

10. The process of claim 9., wherein the halidating solution comprises at least about 10 percent by weight hydrogen halide.

11. The process of claim 5, wherein the aqueous pretreatment solution has a concentration of ferric halide in the range of from about 5 to about g/l iron.

Claims

1. A process for refining a manganese oxide ore, the ore comprising as primary components the oxides of manganese and iron, and further comprising a basic constituent which includes at least one other non-ferrous metal value, the process comprising: pre-treating the ore with an aqueous pretreatment solution of ferric halide to form a solution of the halides of the basic constituents of the ore and solid ferric oxide; separating the pre-treated ore from the resulting aqueous solution and solid ferric oxide; halidating the pre-treated ore with an aqueous solution of a hydrogen halide to form a pregnant aqueous solution comprising dissolved ferric halide, manganese halide and a nonferrous metal Halide; separating the pregnant aqueous solution from the insoluble solids; extracting selectively ferric halide from the pregnant aqueous solution with an extractant selective for the ferric halide and selected from the group consisting of organic amines and organic phosphate esters, to form an aqueous raffinate comprising the manganese halide and the nonferrous metal halide but substantially free from ferric halide, and stripping the ferric halide from the extractant to form an aqueous solution comprising the ferric halide; and cycling the aqueous solution of the ferric halide to pre-treat the manganese oxide ore, prior to halidation with the hydrogen halide.

2. The process of claim 1, wherein the halidation reagent is a hydrogen halide selected from the group consisting of hydrogen bromide and hydrogen chloride.

3. The process of claim 1, wherein the halidation agent is hydrogen chloride.

4. The process of claim 1, wherein the aqueous pretreatment solution has a concentration of ferric halide in the range of from about 5 to about 75 g/l iron.

5. A PROCESS FOR REFINING OCEAN FLOOR NODULC ORE, THE ORE COMPRISING AS PRIMARY COMPONENTS THE OXIDES OF MAGANESE AND OF IRON AND AS SECONDARY COMPONENTS COMPOUNDS OF COPPER, COLBALT AND NICKEL AND FURTHER COMPRISING BASIC CONSITUENTS, THE PROCESS COMPRISING: PRE-TREATING THE ORE WITH AN AQUEOUS SOLUTION OF FERRIC HALIDE TO FORM A SOLUTION OFTHE HALIDES OF THE BASIC CONSTITUENTS OF THE ORE AND SOLID FERRIC OXIDE, SEPARATING THE PRE-TREATED ORE FROM THE RESULTING AQUEOUS SOLUTION AND SOLID FERRIC OXIDE, HALIDATING THE PRE-TREATED ORE WITH AN AQUEOUS HALIDATING SOLUTION OF A HYDROGEN HALIDE TO FORM A PREGNANT AQUEOUS SOLUTION, COMPRISING DISSOLVED MGANESE HALIDE, FERRIC HALIDE, COBALT HAALIDE, COPPER HALIDE AND NICKEL HALIDE, SEPARATING THE PREGNANT SOLUTION FROM THE INSOLUBLE RESIDUEXTRACTING SELECTIVELY THE FERRIC HALIDE FROM THE PREGNANT AQUEOUS SOLUTION BY A PROCESS COMPRISING CONTACTING THE PREGNANT AQUEOUS SOLUTION OF THE METAL HALIDES WITH A LIQUID EXTRACTION MEDIUM IMMISCIBLE WITH THE PREGNANT AQUEOUS SOLUTION AND SELECTIVE FOR THE EXTRACTION OF FERRIC HALIDE AND COMPRISING AN ORGANIC SOLVENT AND AN EXTRACTION AGENT SELECTED FROM THE GROUP CONSISTING OF ORGANIC AMINES ANDD ORGANIC PHOSPHATE ESTERS TO FORM A FERRIC HALIDE EXTRACT AND AN AQUEOUS RAFFINATE COMPRISING THE MAGANESE HALIDE, COBALT HALIDE, COPPER HALIDE AND NICKEL HALIDE BUT SUBSTANTIALLY FREE FROM FERRIC HALIDE, AND STRIPPING THE EXTRACT WITH WATER TO REMOVE THE FERRIC HALIDE THEREFORM AND TO FORM AN AQUEOUS SOLUTION OF FERRIC HALIDE, AND CYCLING THE FERRIC HALIDEAQUEOUS SOLUTION FOR PRE-TREATING THE ORE.

6. The process of claim 5, wherein the hydrogen halide is hydrogen chloride.

7. The process of claim 5, wherein the ore is comminuted to a particle size of not greater than about 10 mesh U.S. Sieve prior to reaction with the ferric halide.

8. The process of claim 6, wherein the pregnant aqueous solution has a pH of not greater than about 2.

9. The process of claim 8, wherein the water for stripping the ferric halide has a pH of not greater than about 2.

10. The process of claim 9, wherein the halidating solution comprises at least about 10 percent by weight hydrogen halide.

11. The process of claim 5, wherein the aqueous pretreatment solution has a concentration of ferric halide in the range of from about 5 to about 75 g/l iron.