CN101517129B - Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes - Google Patents
Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes Download PDFInfo
- Publication number
- CN101517129B CN101517129B CN2007800350588A CN200780035058A CN101517129B CN 101517129 B CN101517129 B CN 101517129B CN 2007800350588 A CN2007800350588 A CN 2007800350588A CN 200780035058 A CN200780035058 A CN 200780035058A CN 101517129 B CN101517129 B CN 101517129B
- Authority
- CN
- China
- Prior art keywords
- electrochemical method
- iron
- alloy
- solution
- metal chloride
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
An electrochemical process for the concurrent recovery of iron metal and chlorine gas from an iron-rich metal chloride solution, comprising electrolysing the iron-rich metal chloride solution in an electrolyser comprising a cathodic compartment equipped with a cathode having a hydrogen overpotential higher than that of iron and containing a catholyte having a pH below about 2, an anodic compartment equipped with an anode and containing an anolyte, and a separator allowing for anion passage, the electrolysing step comprising circulating the iron-rich metal chloride solution in a non-anodic compartment of the electrolyser, thereby causing iron to be electrodeposited at the cathode and chlorine gas to evolve at the anode, and leaving an iron-depleted solution. The iron-rich metal chloride solution may originate from carbo-chlorination wastes, spent acid leaching liquors or pickling liquors.
Description
Technical field
The present invention relates to from the electrochemical method of rich metal chloride wastes waste recovery metal values iron and chlorine.More particularly, the present invention relates to that for example carburizing chlorination (carbo-chlorination) waste material, spent acid leaching liquid, pickle solution or any other rich metal chloride wastes liquid or solution reclaim the electrochemical method of metal values iron and chlorine from the rich metal chloride wastes waste material.
Background of invention
In chemical industry, chlorine (Cl
2) be one of the most widely used inorganic chemical.For example, urethane, halon and white TiO 2 pigment are made in the method for using chlorine usually.
Under the situation that the white TiO 2 pigment of in the end mentioning is made, with chlorine with the raw material chlorination.Chlorinated substance is reduced into useless by product, for example: hydrogenchloride (HCl
Gas), hydrochloric acid (HCl
The aqueous solution) or inorganic metal muriate (for example, FeCl
3, FeCl
2, MgCl
2).
Especially, prepare titanium tetrachloride (TiCl when the carburizing chlorination by titaniferous ore raw material (for example, weathering ilmenite, titanium slag or titania)
4) time, a large amount of iron and metal chloride material produce as by product.These by products can comprise iron protochloride or iron(ic) chloride or their combination, and this depends on the reaction conditions of chlorinator.Actual by product in fact is more complicated, because they are made of the chlorination waste material, this chlorination waste material is made of the blend of following material basically: the granular iron muriate by unreacted titanium material, petroleum coke, silicon-dioxide and silicate pollute reaches other metal chloride.Provide following table 1 from the approximate chemical constitution of the metal chloride only collected with the cyclone of the chlorinator of titanium slag operation.
The average compositing range of metal chloride is represented (wt.%) with anhydrous salt in chlorinator dust when table 1-receives
| Metal chloride | Chemical formula | Percentage |
| Iron(ic) chloride (II) | FeCl 2 | 30-70 |
| Aluminum chloride (III) | ?AlCl 3 | 5-15 |
| Magnesium chloride (II) | ?MgCl 2 | 5-20 |
| Manganous chloride tetrahydrate (II) | ?MnCl 2 | 4-15 |
| Sodium-chlor | ?NaCl | 1-8 |
| Vanadyl chloride (IV) | ?VOCl 2 | 1-6 |
| Chromium chloride (III) | ?CrCl 3 | 0.5-6 |
| Titanium chloride (III) | ?TiCl 3 | 0.1-3 |
The formation of these chlorinator waste materials has serious economy and environmental influence to entire method, can dispose because these waste materials must be processed.Usually, the by product iron chloride is discarded in extensive deep-well or discarded at the ocean landfill yard or be discharged into simply in the waste water stream.The loss fully that abandons the economic worth that causes environmental problem and chloride material like this.Although defectiveness on the environment, these practices still extensively are used in global many factory sites.
Though attempted these metal chloride by products are put goods on the market as the flocculation agent in the wastewater treatment or as the etchant in the pickling bath, these attempt being hindered by the low marketable value of these by products.In addition, because described by product is aqueous solution form usually, trucking costs is too high.
For this reason, to the existing further investigation of chlorine recirculation and four carried out various trials in the titanium dioxide pigment industry during the last ten years and reclaim valuable chlorine in the past from iron chloride.
In addition, owing to passed through the lixiviate of high pressure hydrochloric acid in 1998 with the spissated introduction of titanium slag, people's growing interest reclaims valuable chlorination metallics from spent acid.At present, the spent acid pyrohydrolysis so that the azeotropic solution of hydrochloric acid regeneration, and is stayed inert metal oxides, their are as opening a mine residue by landfill.The average compositing range of spent acid provides in following table 2.
The average compositing range of table 2-spent acid
| Positively charged ion or chemical substance | Concentration (c/g.dm -3) |
| HCl (dissociating) | 40-70 |
| Fe (always) | 30-60 |
| Fe(II) | 20-45 |
| Mg(II) | 10-30 |
| Al(III) | 4-12 |
| Fe(III) | 4-12 |
| Ca(II) | 0.5-2 |
| V(III) | 0.5-2 |
| Mn(II) | 0.5-3 |
| Cr(III) | 0.3-2 |
| Ti(IV) | 0.1-1 |
To this day, still do not reclaim the gratifying commercial run of elemental chlorine from iron chloride.From the main prior art route of useless chloride recovery chlorine is the thermochemistry oxidation of iron chloride excessive oxygen.
Therefore, carry out some around the oxidation of iron chloride and attempted, between the oxidation period of iron chloride, related to following chemical reaction:
2FeCl
2(s)+
3/
2O
2(g)→Fe
2O
3(s)+2Cl
2(g)
2FeCl
3(s)+
3/
2O
2(g)→Fe
2O
3(s)+3Cl
2(g)。
Yet, to this day, verifiedly be very difficult to develop the gratifying commercial run that comprises the reaction of giving an example in the aforesaid equation.Many effort have been made to overcome the difficulty of following, for example people such as Harris by in gas phase, carrying out this reaction
1That points out is such.The Harris suggestion can be handled iron(ic) chloride with oxygen in gas phase in fluidized-bed reactor.This method produces chlorine (it can be recycled to ilmenite or rutile chlorination process) and ferric oxide by product rather than soluble chloride waste material.
GB patent 1,407,034
2Disclose with excessive oxygen enough high with the temperature of the condensation of avoiding iron protochloride under oxidation gaseous state iron protochloride.
The United States Patent (USP) 3,865,920 of RZM Ltd.
3A kind of method is disclosed, this method is included under 980 ℃-1110 ℃ and preheats iron protochloride, then by make pure oxygen through with its oxidation forming the mixture of iron chloride, ferriferous oxide, oxygen and chlorine, this mixture of this postcooling also changes into ferriferous oxide and chlorine with residual chloride iron.
FeCl
2Or FeCl
3Being completely oxidized to the subject matter that ferriferous oxide and chlorine runs into is that thermodynamics requires low temperature, promptly common below 400 ℃, so that balance moves towards the oxidation that helps iron(ic) chloride.Yet as if, under the low temperature by the thermodynamics regulation, it is too slow that reaction kinetics becomes, and at high temperature, when reaction is carried out with practical rates, react complete far from.
Found afterwards that the catalyzer for example use of ferriferous oxide quickened reaction at low temperatures.Therefore, propose use ferriferous oxide fluidized-bed reactor and reduced temperature of reaction.In fact, the United States Patent (USP) 2,954,274 of ColumbiaSouthern Chemical Corp.
4Proposed in the fluidized-bed of iron chloride and the ferriferous oxide of choosing wantonly, under 400 ℃-1000 ℃ temperature, to utilize the air or oxygen oxidation chlorination ferrous.Afterwards, at the United States Patent (USP) 3,793,444 of E.I DuPont de Nemours
5In, the following oxidation of carrying out the gaseous state iron chloride: make the mixture of iron chloride and oxygen have the some Overlay Districts through cutting apart down by wall at the inert solid particle (for example, silica sand) of recirculation.During this method, iron protochloride (FeCl
2) quilt oxidation continuously in a stage, at first be oxidized to iron(ic) chloride (FeCl
3) be oxidized to ferric oxide (Fe then
2O
3).Afterwards, at the United States Patent (USP) 4,144,316 of E.I DuPont de Nemours
6In, Reeves and Hack have improved this method by carry out dechlorination reaction in the recirculation flow fluidized bed reactor, and described fluidized-bed reactor for example has United States Patent (USP) 4,282,185
7The middle type that proposes.
Yet, during thermooxidizing, produce other problem, promptly solid-state, closely knit and hardening oxidation iron dirt (Fe
2O
3) deposition.This dirt has the serious tendency of cumulative and sticks to securely on reactor wall and the supplementary unit, thereby induces reaction device valid function and safeguard the problem of aspect.In fact, verified, the oxide compound dirt on bed, produce even outlet may become soon stopped up fully and often must shut-down operation to remove this dirt, this causes the shutdown of costliness.In addition, when increasing the size of fluidized-bed reactor, the technical scale of this reaction runs into serious problem.
Other proposal is to use the molten salt bath of NaCl to carry out this oxidising process at low temperatures to form salt complex (NaCl-FeCl
3) or eutectic salt; Or under the pressure that is enough to cause iron(ic) chloride liquefaction, carry out this oxidation.Yet these method general requirements are used complex apparatus and operational condition are carried out the control of extreme care.In addition, removing the by product ferriferous oxide from reactor and the adhesion of particulate state bed material, as if meeting difficulty.
The general gaseous chlorine that seemingly produces of another defective of thermal oxidation process of poor quality, i.e. about 75vol% Cl
2, because it be chlorinated iron and other volatile impunty largely ground contamination in addition by unreacted oxygen (11vol% O
2) and carbonic acid gas (7.5vol% CO
2) dilution largely.Therefore, it shows relatively poor commercial value.In addition, relate to big extra-expense to the recirculation immediately of chlorinator and with the spissated effort of rare chlorine.
In addition, the available chlorine by thermooxidizing reclaims the pure basically iron protochloride of requirement as raw material.Yet the mechanical separation of particulate state iron protochloride and principal pollutant in the chlorinator dust (that is coke) is the task of difficulty.In fact, if the thermooxidizing of impure iron protochloride is being carried out above under 800 ℃ the temperature, the coke that then is present in this dust burnouts, thereby produces focus in reactor, this causes this ferriferous oxide accumulative sintering of this oxide compound simultaneously on wall, and this causes stopping up in short period of time again.
After unsuccessful test of thermooxidizing being made by E.I.Du Pont de Nemours and pre-commercial the trial, other TiO 2 pigment producer has studied this technology, for example SCM ChemicalsLtd.
8, Kronos Titan GmbH
9With recent Tioxide
10
Reclaim in the time of for valuable chlorine and iron, consider another kind of route, i.e. the electrolysis route.
From prior art,, just begin from iron-containing liquor electro-deposition ferrous metal since second page or leaf of 18th century.In fact, the whole bag of tricks of electrowinning, plating or electrorefining ferrous metal is known.Usually, the target of these methods is that preparation has highly purified electrolytic iron, takes second place, and is the preparation pure iron powder.Usually, the most frequently used electrolytic solution is based on iron sulfate, inferior commonly used be iron chloride.
Most of known electrochemical method initial design are used at cathode electrodeposition iron, and simultaneously anodic reaction is the anode dissolution of the soluble anode made by non-pure iron usually.In such method,, the consumption-type anodic as if generally can avoid emitting of newborn oxygen of undesirable corrodibility or dangerous chlorine but using.
In anode side, be the technology that document fully writes down by electrolysis from salt solution or by-product salt acid recovery chlorine, the operation of global many factories has the electrolytic process of dispersed number.Yet, will contain the as if appearance as yet of two kinds of principle bonded technical scale electrochemical methods that iron chloride directly reclaims iron and chlorine from giving up.
As if the trial that first kind of document fully writes down trace back to nineteen twenty-eight LEVY
10Patent.This contriver discloses the simple electrochemical method that reclaims newborn chlorine and pure electrolytic iron from the solution of pure iron protochloride simultaneously.Use the barrier film of making by the unglazed clay of porous to divide electrolyzer to prevent the mixing of product as spacer.At 90-100 ℃ at 110-270A.m
-2Current density under adopt the average battery voltage of 2.3-3.0V to carry out electrolysis.Faradaic current efficient is 90-100%.Anolyte is dense chloride soln (for example, CaCl
2, NaCl), and catholyte is to contain 20wt.% FeCl
2The aqueous solution.Anode is a carbon back, and negative electrode is thin plate, axle or other object that is fit to.
In recent years, in nineteen ninety, the people such as OGASAWARA of Osaka Titanium Co.Ltd (Toho now)
12Disclosing in patent application by uniting with three compartment electrolyzers uses negatively charged ion and cationic exchange membrane to produce the electrolysis process of iron and chlorine via the electrolysis of the muriatic aqueous solution of iron content (from the pickling of steel or the ejecta that produces from the method for preparing titanium tetrachloride or non-ferrotitanium ore).In this method of in Ogasawara, giving an example, constitute and with the catholyte of the pH value of the constant 3-5 of being adjusted to of ammonia by the high purity chlorination is ferrous, circulate in the loop of their respective compartment inside with the anolyte that constitutes by sodium-chlor, treat the circulation in central compartment (that is the gap that exists between two ion-exchange membranees) of the electrolytic solution that contains rich iron chloride simultaneously.The negative electrode that uses is iron preferably, but also can be stainless steel, titanium or titanium alloy, and the anode of use is made of insoluble graphite.According to contriver's viewpoint, and use two compartment electrolysis processs opposite, this 3-compartment method as if can avoid the impurity that embeds for example metal oxide pollute the iron of the electrocrystallization of gained.In addition, keeping catholyte pH value can avoid emitting at the hydrogen of negative electrode at 3-5.
Yet, in such method, high resistance drop has appearred, and this is because (i) the additivity resistivity of ion-exchange membrane and the associated gap that (ii) exists between two spacers.In addition, as if graphite anode and sodium chloride brine anolyte use in combination the reaction of emitting chlorine are caused high overvoltage.High resistance drop and anodic overvoltage all contribute to the groove electromotive force.The high specific energy consumption that therefore this cause chlorine and iron to reclaim, this and feasible suitability for industrialized production are not inconsistent.
Therefore, still need to reclaim simultaneously the efficient and economic method of ferrous metal and chlorine from the rich metal chloride wastes waste material.
Specification sheets of the present invention has been quoted many documents, and their content is incorporated in herein by reference in full.
Summary of the invention
Present invention relates in general to from the electrochemical method of rich metal chloride wastes waste recovery metallic iron and chlorine.
More particularly, one aspect of the invention relates to the electrochemical method that reclaims metallic iron and chlorine from rich metal chloride wastes solution, and this method may further comprise the steps:
A) provide rich metal chloride wastes solution;
B) in electrolyzer with this rich metal chloride wastes electrolysis of solutions, electrolyzer comprises: be equipped with the hydrogen overpotential than the high negative electrode of iron and comprise the cathodic compartment of pH value less than about 2 catholyte, be equipped with anode and comprise the anodal compartment of anolyte, with the spacer that allows negatively charged ion to pass through, this electrolysis step comprises circulates this rich metal chloride wastes solution in the non-anodal compartment of this electrolyzer, thereby make the ferroelectric negative electrode and chlorine is emitted at anode of being deposited on, stay poor ferrous solution; With
C) reclaim the iron and the described chlorine of described galvanic deposit respectively.
In a particular, provide the step (a) of rich metal chloride wastes solution may further comprise the steps:
A1) with hot aqueous solution lixiviate solid carburizing chlorination waste material, thus the form aqueous slurry; With
A2) to described aqueous slurry carry out solids constituent from, thereby form insoluble cake and isolate rich metal chloride wastes solution.
In another specific embodiment, it is about 1.8 that the pH value of catholyte is adjusted to about 0.3-, and preferably approximately 0.6-is about 1.5, and more preferably approximately 0.6-is about 1.1, most preferably about 0.9-about 1.1.
In another specific embodiment, negative electrode is at 0.5mol.dm
-3Among the HCl at 25 ℃, 200A.m
-2, have superpotential greater than about 425mV.
In another specific embodiment, negative electrode is configured to or applies by being selected from following material: titanium, titanium alloy, zirconium, zirconium alloy, zinc, zinc alloy, cadmium, cadmium alloy, tin, tin alloy, copper, copper alloy, lead, lead alloy, niobium, niobium alloy, gold, au-alloy, mercury and mercurous metallic amalgam.
Another aspect of the present invention relates to the method that reclaims metallic iron and chlorine from rich metal chloride wastes solution, and this method comprises:
A) provide rich metal chloride wastes solution;
B) this rich metal chloride wastes solution of electrolysis in two compartment electrolyzers, this two compartments electrolyzer comprises the cathodic compartment that is equipped with the hydrogen overpotential negative electrode higher than iron, with be equipped with anode and comprise the anodal compartment of anolyte, negative electrode and anodal compartment are separated by anion-exchange membrane, this electrolysis step comprises making and is adjusted to the pH value and circulates in the described cathodic compartment of described electrolyzer as catholyte less than 2 described rich metal chloride wastes solution, thereby make iron at cathode electrodeposition and chlorine is emitted at anode, stay poor ferrous solution; With
C) reclaim the iron and the described chlorine of described galvanic deposit respectively.
After the non restrictive description of the particular of the present invention that only provides for giving an example below the reference accompanying drawing is read, other purpose of the present invention, advantage and feature will become more obvious.
Brief Description Of Drawings
In the accompanying drawings:
Fig. 1 is the schematic flow sheet of demonstration according to each step of the whole electrochemical method of first embodiment of the invention, and this electrochemical method is based on two compartment electrolyzers and use the rich metal chloride wastes solution of regulating through the pH value to carry out electrolysis;
Fig. 2 is the schematic flow sheet of demonstration according to each step of the whole electrochemical method of second embodiment of the invention, this electrochemical method is based on two compartment electrolyzers and use the rich metal chloride wastes solution of regulating through the pH value to carry out electrolysis, and this had removed vanadium by precipitation through the rich metal chloride wastes solution that the pH value is regulated before it introduces cathodic compartment;
Fig. 3 is the schematic flow sheet of demonstration according to each step of the whole electrochemical method of third embodiment of the invention, and this electrochemical method uses three compartment electrolyzers and carries out electrolysis with unadjusted rich metal chloride wastes solution;
Fig. 4 is the synoptic diagram of the two compartment electrolyzers that use in some embodiments of the present invention, and wherein main electrochemical reaction takes place at each electrode place;
Fig. 5 is the synoptic diagram of the three compartment electrolyzers that use in some embodiments of the present invention, and wherein main electrochemical reaction takes place at each electrode place;
Fig. 6 is the photo that obtains by scanning electronic microscope (SEM), and it shows the general view of the codeposition of the iron that obtained among the embodiment 2a and vanadium;
Fig. 7 is the photo that obtains by scanning electronic microscope (SEM), and it shows the detailed view of the codeposition of the iron that obtained among the embodiment 2a and Vanadium Pentoxide in FLAKES;
Fig. 8 is the smooth electrodeposit photo that shows the iron with a small amount of vanadium that obtains among the embodiment 2b;
Fig. 9 is the photo that shows the galvanic deposit thin plate of the ferrous metal that obtains among the embodiment 5;
Figure 10 is the photo that shows the ferrous metal deposition plate that obtains among the embodiment 6;
Figure 11 is the diagram that shows the polarization curve (selection of cathode material) that obtains among the embodiment 8;
Figure 12 is the diagram that shows the polarization curve (selection of anion-exchange membrane) that obtains among the embodiment 9; With
Figure 13 is the diagram that shows the polarization curve (selection of anolyte) that obtains among the embodiment 10.
Embodiment
Can use various raw materials in the method according to the invention, include but not limited to, carburizing chlorination waste material (for example deriving from the carburizing chlorination of titaniferous ore), spent acid leaching liquid, pickle solution or any other rich metal chloride wastes liquid or solution.Therefore, raw material can be solid-state, anhydrous, slurry form or solution.
Term as used herein " electrolyzer " generally is two compartments or three compartment electrolyzers.All electrolyzers that use in the inventive method comprise anodal compartment and cathodic compartment at least, and they are separated by at least one ion-exchange membrane.
When relating to electrolyzer, term as used herein " non-anodal compartment " is meant the cathodic compartment of two compartment electrolyzers and/or the central compartment of three compartment electrolyzers.For the purpose of clearer, it is not the cathodic compartment of three compartment electrolyzers.
Term as used herein overvoltage (also claiming superpotential) generally be meant electric current by lower electrode electromotive force and do not having difference between the thermodynamics value of electrolytic situation lower electrode electromotive force for same experimental conditions.
When relating to negative electrode, term as used herein " hydrogen overvoltage " be meant with in the relevant overvoltage of negative electrode release hydrogen.Negative electrode with high hydrogen overvoltage makes hydrogen emit during electrolysis and minimizes, and therefore promotes ferroelectric deposit.Known and limiting examples with material of high hydrogen overvoltage for example is given in Cardarelli
13United States Patent (USP) 5,911,869 with Exxon Research and Engineering and Co.
14In.Advantageously, cathode material allows also that ferrous metal is sedimental to be peeled off.The limiting examples of the cathode material that is fit to comprises titanium (industry or more high purity), titanium alloy (for example titanium palladium ASTM grade 7), zirconium (industry or more high purity), zirconium alloy, zinc (industry or more high purity), zinc alloy, cadmium (industry or more high purity), cadmium alloy, tin (industry or more high purity), tin alloy, copper (industry or more high purity), copper alloy, plumbous (industry or more high purity), lead alloy, niobium (industry or more high purity), niobium alloy, gold (industry or more high purity), au-alloy, mercury and mercurous metallic amalgam.
It should be understood that the negative electrode with high hydrogen overvoltage can be made of the body of the material with high hydrogen overvoltage or can be simply with such coated materials.
When describing negative electrode, the employed statement of this paper " hydrogen overvoltage is than iron height " is meant that negative electrode is at 0.5mol.dm
-3Among the HCl under 25 ℃, 200A.m
-2, have the superpotential of absolute value greater than about 425mV.
It should be understood that the cognation of carrying out according to some optional step of the inventive method depends on given element to be recycled existence in raw material.For example, the not all raw material that may be used for the method according to this invention all contains vanadium.Certainly, if vanadium is present in the raw material, then the vanadium separating step only is correlated with.
The employed statement of this paper " vanadium separating step " is meant basically with vanadium and iron separation steps.Therefore, it can corresponding to, but not necessarily such step wherein reclaims vanadium with pure basically vanadium compound.
Raw material is in the embodiment of solid and/or anhydrous form therein, described method at first is usually with raw material, for example at the anhydrous chlorides of rase device dust of by-product during the carburizing chlorination of the raw material (for example, weathering ilmenite, titanium slag, natural and titania) of rich titanium dioxide with any lixiviate in the following material: the acid process water of heat, hot dilute hydrochloric acid, carry from the high pressure acidleach of titanium slag or even come the hot spent acid of the waste liquid of by-product during the pickling of comfortable steel.After the dissolving fully of all metal chlorides, with the slurries filtration of gained and the residual insoluble solid that comprises unreacted oxidation titanium slag, silicon-dioxide and silicate, titanium dioxide fines and coke fraction is separated with the soluble metal muriate that is rich metal chloride wastes liquid or solution form.With the filter cake that the careful washing of minimum sour water is obtained, dehydration, dry and send carburizing chlorination equipment at last back to or abandon and landfill (depend on its valuable titanium and coke, and the content of silicon-dioxide), washing water can be used further to the first lixiviate step simultaneously.
Raw material is in another embodiment of slurry form therein, and lixiviate can help soluble solids in solid-liquid separation (for example by filtering) dissolving before.
In another embodiment, wherein raw material is clarification water-based liquid form, i.e. the clarification water-based liquid form of rich metal chloride wastes solution, and the lixiviate step is not important especially.
Afterwards, three kinds of main method variants can be used for reclaiming valuable chlorine and metal simultaneously from rich metal chloride wastes solution, they are based on reclaiming the identical General Principle of metal values iron and chlorine by electrolysis simultaneously from rich metal chloride wastes solution, use to be adjusted to the negative electrode that the pH value is higher than iron less than 2 catholyte and hydrogen overvoltage.
In a particular according to the inventive method, as shown in Figure 1, at first use alkaline reagents such as but not limited to, magnesium oxide or ammonium hydroxide or their mixture are adjusted to about 0.6-about 1.8 with the pH value of rich metal chloride wastes solution, after this, this solution prepares to be used for electrolysis.
Still with reference to Fig. 1, electrolysis stage relates to makes the rich metal chloride wastes solution circulated of regulating through the pH value in the cathodic compartment inside of electrolyzer.Therefore this rich metal chloride wastes solution serve as catholyte.Electrolyzer constitutes (as shown in Figure 4) by two compartments being separated by anion-exchange membrane.Cathodic compartment comprises the negative electrode of being made by titanium or titanium alloy (normally the ASTM grade 7), and anodal compartment has the anode (DSA that emits dimensional stabilizing to chlorine
TM-Cl
2).In anodal compartment with the anolyte of circuit cycle by about 20wt.% hydrochloric acid and about 17wt.% magnesium chloride and about 10,000ppm is as the ferric iron (Fe of inhibitor agent
3+) mixture constitute.
During electrolysis, under the above-mentioned pH value of about 0.6-about 1.8, ferrous metal with the precipitation crystal of Vanadium Pentoxide in FLAKES in cathodic deposition.The precipitation of Vanadium Pentoxide in FLAKES causes by improving in the consumption of the hydrogen cation at negative electrode place with greater than the part of the pH value of the set point of hydration Vanadium Pentoxide in FLAKES.On the other hand, according to following electrochemical reaction, cl anion discharges as chlorine towards the migration of anode compartment and in the anodic surface through seeing through anionic exchange membrane:
Fe
2+(aq)+2e
-→ Fe
0(s) (negative electrode-)
2Cl
-(aq) → Cl
2(g)+2e
-(anode+).
Therefore total reaction is:
FeCl
2→Fe(s)+Cl
2(g)。
Also side reaction may take place, for example oxygen is emitted at anodic:
2H
2O(l)→O
2(g)+4H
+(aq)+4e
-，
Hydrogen is emitted at negative electrode:
2H
+(aq)+2e
-→H
2(g)，
And the cationic reduction of trace ferric iron:
Fe
3+(aq)+e
-→Fe
2+(aq)。
At cathode side, following these undesirable side reactions are minimized: the pH value of keeping catholyte is less than about 2 and use discharging to hydrogen to have high superpotential cathode material and emit to prevent hydrogen.More particularly, the cathode material that is used for the method according to this invention has the hydrogen overvoltage higher than iron (pressing absolute value) under given electrolytic condition.Preferably, it is about 1.8 that the pH value of catholyte is maintained about 0.6-, and preferably approximately 0.6-is about 1.5, and it is about 1.1 to be more preferably about 0.6-, most preferably about 0.9-about 1.1.In addition, above cathodic compartment, use the inert atmosphere of nitrogen can help prevent ferrous cationic, oxidized.
In anode side, the anode that use is emitted dimensional stabilizing to chlorine can stop emitting of oxygen, thereby guarantees the generation of high purity chlorine.
Electrolysis is carried out under continuous current control (galvanostaticcontrol) at about 40 ℃-about 110 ℃ usually.Overall current density is at about about 2000A/m of 200-
2, wherein cell voltage is the about 3.5V/ battery of about 1.2-.In this specific embodiment, faradic efficiency is usually greater than about 90%, and the average specific energy consumption is about 6.2kWh/ kilograms of iron of about 2.1-and the about about 3.5kWh/ kilogram of 1.1-chlorine.
Reclaim the wet chlorine of emitting by ordinary method.For example, as shown in Figure 1, can reclaim, its is cooled off through graphite heat exchanger, and make its through moisture trap and some vitriol oil spray towers (washing) drying in addition by suction.At last, can and make it liquefaction with dry and cold chlorine compression, thereby preparation is carried or stored on-site is standby.
Mechanically peel off the slab of the ferrous metal of galvanic deposit from the titanium negative electrode.Then this plate is immersed the heat alkali liquid (50wt.% NaOH) of concentrated sodium hydroxide optionally to dissolve barium oxide; Add oxide in trace quantities since agent (oxydiser), such as but not limited to, Potcrate is to change into all vanadium the pentavalent vanadium and to reclaim the pure iron metal individually.Then with ammonia together with ammonium chloride (NH
4Cl) and/or ammonium hydroxide add to together in the residual liquid so that all vanadium as ammonium meta-vanadate (NH
4VO
3) precipitation.Therefore, in such particular, the vanadium separating step carries out after electrolysis step.
Add sulfuric acid to leave electrolyzer useless nonferrous electrolytic solution, or in the poor ferrous solution, so as with calcium as insoluble calcium sulfate dihydrate (CaSO
4.2H
2O) remove and carry secretly optional trace level activity material (radioactivity), great majority are radium sulfate.
Then with the salt solution pyrohydrolysis of residual useless rich magnalium to produce refractory spinel pearl, pellet or the particle of preparing to be used to make refractory material or propping agent (proppant), reclaim azeotropic hydrochloric acid simultaneously.
It should be understood that in the method for Fig. 1 the pH value that changes catholyte, for example change to 0.3-0.5, vanadium is not precipitated along with the iron codeposition, but stay this richness iron, in the solution of the poor iron that becomes, thereby during electrolysis, carry out the vanadium separating step.Yet this is not an embodiment preferred in the method for using two compartment electrolyzers, because the iron that is obtained may be polluted (though slight) by Vanadium Pentoxide in FLAKES and faradic efficiency may descend.
In another particular, as the general demonstration of Fig. 2, measure the accurate content of vanadium of rich metal chloride wastes solution and introduce stoichiometric Potcrate (KClO by ordinary method according to the inventive method
3) all vanadium are oxidized to vanadium (V) (not shown).Add the iron(ic) chloride (III) of respective amount then and for example magnesium oxide or ammonium oxide, ammonium hydroxide or their mixture are adjusted to about 0.5-about 3 with the pH value of solution with alkaline reagents.Make vanadium (V) and chromium (Vl) coprecipitation like this, carry ironic hydroxide (iron (OH) secretly by co-precipitation
3).From slurry, remove the rich vanadium precipitation of gel by decantation, centrifugation or filtering known technology then.The rich vanadium precipitation (for example being cake form) that will so obtain then is dissolved in the strong caustic of minimum quantity and uses oxide in trace quantities since agent (oxydiser) oxidation.Abandon residual iron hydroxide and chromium oxyhydroxide and pass through to add ammonium hydroxide (NH
4OH) and/or ammonium chloride (NH
4Cl) optionally make vanadium as ammonium meta-vanadate (NH
4VO
3) precipitation, and reclaim.
The clear filtrate or the supernatant liquid pH value that derive from the vanadium separating step are adjusted in less than 2, and preferably approximately 0.6-is about 1.8, and therefore with poor vanadium and be used for electrolysis through the rich metal chloride wastes solution (not shown) form preparation that pH value is regulated.
Still with reference to Fig. 2, electrolysis relates to the rich metal chloride wastes solution circulated that makes poor vanadium and regulate through the pH value in the cathodic compartment inside of electrolyzer.Therefore rich metal chloride wastes solution serve as catholyte.Be similar to Fig. 1, electrolyzer is made of battery, and this battery is cut apart (as shown in Figure 4) by anion-exchange membrane.Cathodic compartment has the negative electrode of being made by metal titanium or titanium alloy (normally the ASTM grade 7).Anodal compartment has the anode (DSA that emits dimensional stabilizing to chlorine
TM-Cl
2).With the anolyte of circuit cycle by about 20wt.% hydrochloric acid and about 17wt.% magnesium chloride about 10 with as inhibiter, the ferric iron (Fe of 000ppm
3+) mixture make.During electrolysis, according to following electrochemical reaction, the pure iron metal deposition is in negative electrode, and cl anion is through seeing through anionic exchange membrane and move to anodal compartment and discharging as chlorine on the anodic surface simultaneously:
Fe
2+(aq)+2e
-→ Fe
0(s) (negative electrode-)
2Cl
-(aq) → Cl
2(g)+2e
-(anode+).
Total reaction is:
FeCl
2→Fe(s)+Cl
2(g)。
Equally, also side reaction may take place, for example oxygen is emitted at anode:
2H
2O(l)→O
2(g)+4H
+(aq)+4e
-，
Hydrogen is emitted at negative electrode:
2H
+(aq)+2e
-→H
2(g)，
And the cationic reduction of trace ferric iron:
Fe
3+(aq)+e
-→Fe
2+(aq)。
Equally, at cathode side, the pH value by keeping catholyte is less than 2 and by the cathode material that use has a high hydrogen overvoltage these undesirable side reactions are minimized.The cathode material that is suitable for the method according to this invention has the hydrogen overvoltage higher than iron (pressing absolute value) under given electrolytic condition.Preferably, it is about 1.8 that the pH value of catholyte is maintained about 0.6-, and preferably approximately 0.6-is about 1.5, and it is about 1.1 to be more preferably about 0.6-, most preferably about 0.9-1.1.In addition, above cathodic compartment, use the inert atmosphere of nitrogen can help prevent ferrous cationic, oxidized.
In anode side, the anode that use is emitted dimensional stabilizing to chlorine can stop emitting of oxygen, thereby guarantees the generation of high purity chlorine.
In the embodiment of Fig. 2, electrolysis is carried out under continuous current control at about 40 ℃-about 110 ℃ usually.Overall current density is at about about 2000A/m of 200-
2, wherein cell voltage is the about 3.5V/ battery of about 1.9-.In this specific embodiment, faradic efficiency is usually greater than 90%, and specific energy consumption is usually in the approximately about 3.7kWh/ kilograms of iron of 2-and the approximately about 3kWh/ kilogram of 1.6-chlorine.
In this particular, reclaim the wet chlorine emit by suction, its is cooled off through graphite heat exchanger, and make its through moisture trap and some vitriol oil spray towers (washing) drying in addition.At last, with the compression of dry and cold chlorine with make it liquefaction, thereby prepare to carry or stored on-site in order to re-using.
Mechanically peel off the slab of the pure iron metal of galvanic deposit from the titanium negative electrode.
Add the vitriol oil to leave electrolyzer useless nonferrous electrolytic solution, or in the poor ferrous solution, so as with calcium as insoluble calcium sulfate dihydrate (CaSO
4.2H
2O) remove and carry secretly optional trace level activity material, great majority are radium sulfate.
Then with the salt solution pyrohydrolysis of residual useless rich magnalium to produce refractory spinel pearl, pellet or the particle of preparing to be used to make refractory material or propping agent, reclaim azeotropic hydrochloric acid simultaneously.
In another particular, as shown in Figure 3, under without any the situation of anticipating (for example the pH value is regulated), rich metal chloride wastes solution is delivered to electrochemical appliance according to the inventive method.The design of electrolysis cells (as shown in Figure 5) that is used for this method has three compartments: the cathodic compartment that (i) has titanium plate cathode, (ii) comprise chlorine is emitted the anodic anodal compartment of dimensional stabilizing and (iii) separated by cationic exchange membrane and cathodic compartment and by the central compartment of anion-exchange membrane with the anodal compartment separation.Catholyte in the cathodic compartment internal recycling is iron protochloride (about 350g/L FeCl
2) and magnesium chloride (about 220g/L MgCl
2) saturated solution, and anolyte is by about 20wt% hydrochloric acid and about 17wt.% magnesium chloride and about 10,000ppm is as the ferric iron (Fe of inhibiter
3+) constitute.The pH value of catholyte is adjusted to less than pH value 2, and it is about 1.8 preferably to be adjusted in about 0.6-, and it is about 1.5 to be more preferably about 0.6-, and also more preferably approximately 0.6-is about 1.1, most preferably about 0.9-about 1.1.Make rich metal chloride wastes solution pass central compartment continuously.During electrolysis (Fig. 5), the ferrous cation transport of rich metal chloride wastes solution is through cationic exchange membrane and be reduced into the pure iron metal to the titanium negative electrode, cl anion is through the anode migration of anion-exchange membrane towards dimensional stabilizing simultaneously, at this dimensionally stable anode, they are oxidized, thereby produce the chlorine of emitting.The electrochemical reaction that relates to is as follows:
Fe
2+(aq)+2e
-→ Fe
0(s) (negative electrode-)
2Cl
-(aq) → Cl
2(g)+2e
-(anode+).
Total reaction is:
FeCl
2→Fe(s)+Cl
2(g)。
Electrolysis is carried out under continuous current control for about 110 ℃ at about 40-, and wherein overall current density is at about about 2000A/m of 200-
2, cell voltage is the about 3.5V/ battery of about 1.9-.In this embodiment, faradic efficiency is usually greater than about 90%.
In this embodiment, reclaim the pure and mild wet chlorine emit, its is cooled off through graphite heat exchanger, and make its in addition dry through moisture trap and some vitriol oil spray towers by suction.At last, with dry and cold chlorine compression liquefaction then, thereby preparation is carried or stored on-site is standby.
Mechanically peel off the slab of the pure iron metal of galvanic deposit from the titanium negative electrode.
With hydrogen peroxide (H
2O
2) add in the poor ferrous solution that leaves central compartment so that all trace vanadium (IV and V) are oxidized to vanadium (V).Add magnesium oxide (MgO) then so that the pH value is adjusted to about 1.8-2.2, this causes hydration Vanadium Pentoxide in FLAKES (V
2O
5.250H
2O) quantitatively precipitate.Remove precipitation by decantation, filtration or centrifugation, dry also calcination is to produce Vanadium Pentoxide in FLAKES (V
2O
5) the thin slice (not shown).
Afterwards, sulfuric acid is added in the salt solution of the iron-free of gained and vanadium so that the radioactive substance of trace is removed and carried secretly to calcium as insoluble calcium sulfate dihydrate, great majority are radium.The salt solution pyrohydrolysis of rich magnalium will give up then produce to prepare to be used to make refractory spinel pearl, pellet or the particle of refractory material or propping agent, reclaim azeotropic hydrochloric acid simultaneously.
Be to be noted that when using three compartment electrolyzers the pH value that before electrolysis, can regulate or can not regulate rich metal chloride wastes solution.Though this kind adjusting may for example cause the vanadium precipitation along with deposition of iron, as above-mentioned, is not embodiment preferred at this.
Can change many parameters, as following illustrating according to the inventive method.
The cathode material (as body or coating material) that is suitable for the inventive method is that emitting of hydrogen had high overvoltage, more particularly, and the hydrogen overvoltage material higher under given electrolytic condition than iron.Advantageously, cathode material allows also that ferrous metal is sedimental to be peeled off.The limiting examples of the cathode material that is fit to comprises titanium (industry or more high purity), titanium alloy (for example titanium palladium ASTM grade 7), zirconium (industry or more high purity), zirconium alloy, zinc (industry or more high purity), zinc alloy, cadmium (industry or more high purity), cadmium alloy, tin (industry or more high purity), tin alloy, copper (industry or more high purity), copper alloy, plumbous (industry or more high purity), lead alloy, niobium (industry or more high purity), niobium alloy, gold (industry or more high purity), au-alloy, mercury and mercurous metallic amalgam.
The anode material that is suitable for the inventive method comprises (as body or coating material) (1) [M/M
xO
y-A
zO
t] anode (DSA that emits dimensional stabilizing to chlorine of type
TM-Cl
2), it is made by the metal base or the base metal M that scribble the mixed metal oxide (MMO) as eelctro-catalyst, wherein M is refractory metal or alloy with valve action performance, for example titanium, titanium alloy, zirconium, zirconium alloy, hafnium, hafnium alloy, vanadium, vanadium alloy, niobium, niobium alloy, tantalum, tantalum alloy, M
xO
yBe the metal oxide of valve metal, it forms the impermeable thin layer of protecting group substrate, for example is TiO
2, ZrO
2, H
fO
2, NbO
2, Nb
2O
5, TaO
2And Ta
2O
5, A
zO
tBe the electrocatalysis metal oxide of precious metal, or the more generally oxide compound of platinum metals (PGM), for example RuO
2, IrO
2Or P
tO
x, be SnO for example in addition sometimes
2, Sb
2O
5, Bi
2O
3Metal oxide; (2) body electroconductibility pottery, for example: the substoichiometric titanium oxide is as having general formula Ti
nO
2n-1The Magneli-Anderson phase of (wherein n is＞=3 integer); Has spinel structure (AB
2O
4, wherein A is Fe (II), Mn (II) or Ni (II), B is Al, Fe (III), Cr (III) or Co (III)) electroconductive oxide; Or has a perovskite structure (ABO
3, wherein A is Fe (II), Mn (II), Co (II) or Ni (II), B is Ti (IV)) or have pyrochlore constitution AB
2O
7Electroconductive oxide; Or (3) carbon-based material for example graphite, impervious graphite or vitreous carbon.
The anode electrolysis fluid composition that is used for the inventive method advantageously comprises hydrochloric acid, and salt is MgCl for example
2, NaCl, CaCl
2Or their mixture and as the iron (III) of inhibiter.For example, the anode electrolysis fluid composition of Shi Heing can change in following scope: about about 37wt.% hydrochloric acid of 10-(preferably approximately 20%); About about 20wt.% MgCl of 1-
2, NaCl, KCl, LiCl, CaCl
2Or their mixture (preferably approximately 16%) and about 10-are about 12, and 000ppm wt. is as the Fe (III) of inhibiter (preferred 8,000-10,000ppm wt).
In the embodiment that relates to three compartment electrolyzers of the present invention, the catholyte fluid composition can change in following scope: the approximately about 450g/L iron(ic) chloride of 1-(II) (preferably approximately 335g/L), the approximately about 350g/L MgCl of 1-
2(preferably approximately 250g/L), the approximately about 350g/L CaCl of 1-
2(preferably approximately 250g/L) or about 350g/L MgCl
2And CaCl
2Mixture (preferably approximately 250g/L); It can also further comprise the free HCl of the about 10g/L of 0-.In such embodiments, it is about 1.5 that catholyte pH value is generally about 0.6-, and preferably approximately 0.6-is about 1.1, more preferably about 0.9-about 1.1.
Temperature of reaction can be about 110 ℃ of about 40-, about 95 ℃ of preferably approximately 80-.Most preferably, service temperature is about 85 ℃.
The volumetric flow rate of anolyte and catholyte advantageously is the about 100L/min of about 0.1-, the about 30L/min of preferably approximately 0.1-.Most preferably, volumetric flow rate is about 2L/min.
For the smooth settling of ferriferous no dentrite, the cathode current density during electrolysis advantageously is the about 1000A/m of about 50-
2Preferably, in the case, cathode current density is about 500A/m
2
In order to produce iron powder, the cathode current density during electrolysis advantageously is the about 5000A/m of about 3000-
2Preferably, in the case, cathode current density is about 4000A/m
2
The spacer that is used for the inventive method can be an inert, for example conventional barrier film spacer, or active, for example ion-exchange membrane.Preferably, the spacer of use is an ion-exchange membrane.The anion-exchange membrane and the cationic exchange membrane that are used for the inventive method are conventional films.The limiting examples of the anion-exchange membrane that is fit to provides (Figure 12) below among the embodiment.
Can also change electrode gap, resistance drop is had known influence.It is about 6mm advantageously.
To illustrate in greater detail the present invention via following non-limiting example below.
The preparation of rich metal chloride wastes solution separates with unreacted solid.
A collection of 10 kilograms of anhydrous chlorides of rase device dust, the by product of the carburizing chlorination of promptly spissated rich titanium dioxide slag (UGS) is provided by the TiO 2 pigment producer.At first this material is mixed the metal chloride that goes out all solubilities with lixiviate with the hot acidified water that comprises 10g/L free hydrochloric acid (HCl) at first down at 80 ℃.After the dissolving fully of soluble salt, under vacuum, use big 240-mm internal diameter Bu Shi (Buchner) funnel (CoorsTek) that has 4.5 liters of capacity separately to filter the heat and the closely knit slurry of gained.This B is installed in be connected with vacuum pump 10 liters according to formula (Erlenmeyer) vacuum flask (Kimax) top.The filtration medium that uses is discoid ashless filter paper No.42 (Whatman).In order to improve turnout, operate four in these Bu Shi-Yi Shi assembly simultaneously in parallel.
The filter cake that is obtained with minimum calorimetric and acidifying deionized water wash by the acetone dehydration, is put into Stainless Steel Kettle carefully, dries a whole night down at 110 ℃ then.Draw from micrography and chemical analysis, residual insoluble solid mainly comprises the precipitation fines and the coke fraction of unreacted titanium slag, silicon-dioxide and silicate, titanium dioxide.The example of these solid chemical constitutions that obtain after drying provides in following table 3.
The composition (wt.%) of the insoluble solid of table 3-after hot acid flooding and drying
After filtering and washing finishes, washing water and four kinds of filtrate is 18L altogether, and they are collected in the big 5US-gallon drums shape groove of being made by polypropylene.The concentration of metal chloride in this initial soln provides in table 4 after lixiviate.Because the concentration of iron(ic) chloride in this filtrate (II) (being 83.7g/L) for be enough to obtain to carry out under the smooth sedimental cathode current density for the electrolysis low excessively, so by being evaporated to greatly according to further concentrating this solution in the formula flask, this goes up heating according to the formula flask at hot plate (Corning) greatly.When the volume of solution reduces to 1/4th (4.5L), stop evaporation.In that stage, the concentration of metal chloride improves and widely when reaching 335g/L (referring to table 4, strong solution) at 80 ℃ of when sampling iron(ic) chloride (II).Therefore the crystallization of iron protochloride in order to prevent from room temperature to cool off is transferred to this solution in the glass reactor (Kimble-Contes) of 10L strap clamp cover immediately, and this glass reactor is by the circulating hot water heating of heating bath (Lauda GmbH) supply.Always with the temperature maintenance of solution at 80 ℃.Also by adding micro-this solution of concentrated hydrochloric acid acidifying with the about 10g/L of the concentration of keeping free acid.In fact, under less than 0.5 pH value, ferrous (Fe
2+) to ferric iron (Fe
3+) atmospheric oxidation slow down.In addition, be for anti-oxidation equally, also above this solution, keep nitrogen blanket, and the acrylic sphere that swims in the little cm size on this solution helps prevent because the remarkable water loss that evaporation causes.So the solution of preparation and storage prepares to be used for the step of back.
The concentration (g/L) of metal chloride in the rich ferrous solution of table 4-
Embodiment 2
Embodiment 2a-(the initial electrolysis of concentrated rich metal chloride wastes solution under pH value 1.1).-aforementioned rich metal chloride wastes the strong solution that will derive from embodiment 1 by the magnesium oxide that adds trace simply is adjusted in pH value 1.1, then in the cathodic compartment internal recycling of electrolyzer.Electrolyzer is made of the pressure filter Design Mode MP battery that derives from Electrocell AB (Sweden), its have by by
Two compartments that the anion-exchange membrane that I-200 (SnowPure LLC) makes is separated.The geometrical surface of electrode and film is 100cm
2, the spacing of each electrode and spacer is 6mm.
Cathodic compartment comprises by titanium palldium alloy (ASTM grade 7; Ti-0.15Pd) negative plate of making, this titanium palldium alloy is provided by Titanium Industries.Before electrolysis, by negative electrode being immersed fluoro-nitrate mixture (the dense HNO of 70vol%
3, the dense HF of 20vol% and 10vol%H
2O), up hill and dale its is washed up to there not being the sour residual of trace with deionized water then with its chemical erosion.
Anode (the DSA of the dimensional stabilizing that is provided by Magneto BV (Netherlands) is provided anodal compartment
TM-Cl
2), it is by scribbling high loading ruthenium dioxide (RuO
2) titanium-palldium alloy base material (Ti-0.15Pd/RuO
2) plate make, described ruthenium dioxide serves as eelctro-catalyst and is used to promote emitting of chlorine.With the anolyte of loop recirculation by 20wt.% hydrochloric acid and 17wt.% magnesium chloride (MgCl
2) and 10,000ppm is as the ferric iron (Fe of inhibiter
3+), and the aqueous solution of surplus deionized water constitutes.With 500A/m
2Overall current density continuous current ground carry out electrolysis.Service temperature is that the volumetric flow rate of 80 ℃ and catholyte and anolyte all is 1L/min.Under this current density, total cell voltage of measurement is 2.528V.During electrolysis, the pure iron metal deposition is in negative electrode.On the other hand, according to following electrochemical reaction, cl anion discharges as chlorine towards the migration of anode compartment and in the anodic surface through seeing through anionic exchange membrane:
Fe
2+(aq)+2e
-→ Fe
0(s) (negative electrode-)
2Cl
-(aq) → Cl
2(g)+2e
-(anode+).
Total electrochemical reaction is:
FeCl
2→Fe(s)+Cl
2(g)。
After two hours continuous electrolysis, cut off the electricity supply and open electrolyzer.By mechanical process easily from the thin plate of the coarse and blackening of titanium cathodic disbonding galvanic deposit.The thickness of measuring is that about 0.126mm and its quality only are 8.30g.After the close examination, it in fact is the ferrous metal electrodeposit, has the little crystal grain of pure Vanadium Pentoxide in FLAKES crystalline (seeing Fig. 6 and 7) of embedding under scanning electronic microscope (SEM).After carrying out the final chemical analysis of body sample, it is by 68wt.% iron and 32wt% Vanadium Pentoxide in FLAKES (V
2O
5) constitute.The codeposition of Vanadium Pentoxide in FLAKES may be owing to the following fact: at cathode surface, and hydronium(ion) positively charged ion (H
+) be reduced into hydrogen and emit, thus partly, this H
+Dilution causes the raising of pH value, and this causes the Vanadium Pentoxide in FLAKES solids precipitation, embeds in the ferroelectric throw out.From these experimental results, the faradaic current efficient of estimation is 80% and at 500A/m
2Under specific energy consumption be 3.033kWh/kg settling (iron+Vanadium Pentoxide in FLAKES) or 4.460kWh/kg pure iron.
Use the peristaltic pump with Viton pipe (Masterflex L/S Digital Pump) in downstream to reclaim the wet chlorine of emitting by suction.At first by this chlorine is cooled off it through the borosilicate glass washing bottle that immerses the sky in the ice bath, then by making this gas through the some vitriol oil (98wt.% H that are full of
2SO
4) flask remove mist elimination and moisture content, at last dry and cold chlorine is fully absorbed in the saturated solution of potassiumiodide (KI) and goes, thus according to following reaction release iodine:
Cl
2(gas)+3K
+ Aq+ 3I
- Aq→ 3K
+ Aq+ I
3 - Aq+ 2Cl
- Aq
After electrolysis is finished, by Sulfothiorine (Na
2S
2O
3) standardized solution according to following reaction titration free-iodine:
4Na
+ aq+2S
2O
3 2- aq+K
+ aq+I
3 - aq→4Na
+ aq+S
4O
6 2- aq+K
+ aq+3I
- aq。
Based on titration, the anode faradic efficiency aspect chlorine is based upon 78%.Difference between two kinds of current efficiency (anode and negative electrode) is probably owing to emitting at some hydrogen of negative electrode and emitting at some oxygen of anode.At 500A/m
2Therefore Xiayang ultimate ratio energy consumption is 2.45kWh/ kg of pure chlorine (that is 7.652kWh/m,
3(NTP:0 ℃, 101.325kPa)).
Embodiment 2b (the initial electrolysis of concentrated rich metal chloride wastes solution under pH value 0.30).-as the replacement scheme of embodiment 2a, the rich metal chloride wastes strong solution of embodiment 1 is adjusted in 0.30 quite low pH value down, so that prevents to bring up to precipitation pH value greater than Vanadium Pentoxide in FLAKES in cathode surface pH value, yet, low only, so as not to helping emitting of hydrogen.This reaches by interpolation and circulation hydrochloric acid in the cathodic compartment of electrolyzer.That describes among electrolyzer and the embodiment 2a is identical, just at this moment at 1000A/m
2Current density under continuous current carry out electrolysis.Under this current density and low pH value, the cell voltage that records is 2.865V.After one hour, easily peel off bright and slick electrodeposit from titanium negative electrode (see figure 8).It has the only quality of 6.24g.It is by 99.88wt.% iron and 0.12wt% Vanadium Pentoxide in FLAKES (V only
2O
5) constitute.From these experimental results, the faradaic current efficient of estimation be 60% and the specific energy consumption under 1000A/m2 be 4.584kWh/kg iron.
By with embodiment 2a in the same procedure described reclaim the wet chlorine of emitting.
Reclaiming iron and vanadium-with metal deposit from the iron of embodiment 2a-vanadium settling is ground to the pulverisette shredder (Fritsch) and with powder liquid caustic (NaOH 50wt.%) with sodium hydroxide under pressure of gained and handled two hours down at 100 ℃, handle in the digestion jar (digestion bomb, Parr Company) of 125mL PTFE lining.After cooling, this solution is filtered to reclaim amounts of insoluble iron metal fines.Then, with excess chlorination ammonium (NH
4Cl) add in the rich vanadium liquid so that pure ammonium meta-vanadate (NH
4VO
3) precipitation.After a while in porcelain boat inside in dry air under 400 ℃ in box-type furnace (Fisher Isotemp) this pure ammonium meta-vanadate of roasting to discharge ammonia (NH
3) and water vapour (H
2O), thus produce the red-orange powder of Vanadium Pentoxide in FLAKES.Then with this powder transfer in the lnconel crucible and in fusion and make the melt curtain coating on cold steel plate in air under 700 ℃.Use acetone to be ground in the two disc vibration cup shredders (Fritsch GmbH) with hardmetal lining then as grinding aid and refrigerant the atrament that solidifies with semimetallic lustre with gained.The product that is obtained is the technical grade vanadium pentoxide powder.
Embodiment 4
Before electrolysis, from the rich metal chloride wastes solution of embodiment 1, remove vanadium-with the sodium chlorate (NaClO of stoichiometry
3) add among the embodiment 1 in the initial soln of preparation with according to following reaction with all vanadium positively charged ion (V
4+, V
5+) be oxidized to pentavalent vanadium (V
5+):
5VO
2++ClO
3 -+2H
2O→5VO
2 ++0.5Cl
2(g)+4H
+。
The interpolation that is to be noted that sodium chlorate also can be carried out after the concentrating of solution.
Afterwards, with the iron(ic) chloride (FeCl of equivalent amount
3) introduce this solution to strengthen the co-precipitation of Vanadium Pentoxide in FLAKES and ironic hydroxide.This kind co-precipitation is used for promoting the precipitation fully of vanadium.In fact, if vanadium is unique sedimentary material, then precipitation will be in this solution vanadium concentration stop during less than about 0.02mol/L.
Sorrel hydration Vanadium Pentoxide in FLAKES (V) begins precipitation in about pH value 1.8, and brown ironic hydroxide (III) begins precipitation in about pH value 2.0.Therefore, when two kinds of materials all existed, they were in pH value 1.8-2.0 co-precipitation.Under these circumstances, by the loose magnesium oxide of careful interpolation (Mg (OH)
2) the slurry pH value that improves solution reach 2.0 up to pH value, but never above to avoid the precipitation of the ferrous-iron hydroxide of black mixing.Under such pH value, hydration Vanadium Pentoxide in FLAKES (V
2O
5250H
2O) and the complete coprecipitate of ironic hydroxide (III) occur with gel reddish-brown precipitation form.By using similar this coprecipitate of filtering separation that is provided with of describing with embodiment 1.
And then the filtrate of acidifying gained is to regulate the pH value near 0.5 and be stored in the jacketed reactor up to ensuing electrolysis step.
Take off this sorrel gel filter cake and digestion to the warm liquid caustic (NaOH 50wt.%) of sodium hydroxide from filter paper.After cooling, all pour in the centrifugal polypropylene vial of 250mL solution and sludge also centrifugal down at 10,000 rev/mins with robust benchtop (powerful worktable) whizzer (deriving from the CL4 of Thermo Electron).At bottom separatin non-soluble and closely knit gel residue (mainly by ironic hydroxide (Fe (OH)
3) form), washing carefully with hot alkaline water (pH value 10), recentrifuge abandons then.Then, with excess chlorination ammonium (NH
4Cl) add in the supernatant liquid of rich vanadium so that pure ammonium meta-vanadate (NH
4VO
3) precipitation.After a while in porcelain boat inside in dry air under 400 ℃ in box-type furnace (Fisher Isotemp) this pure ammonium meta-vanadate of roasting to discharge ammonia (NH
3) and water vapour (H
2O), thus produce the red-orange powder of Vanadium Pentoxide in FLAKES.Then with this powder transfer in the lnconel crucible, fusion in air under 700 ℃, and curtain coating is on cold steel plate.Use acetone to be ground in the two disc vibration cup shredders (Fritsch GmbH) with hardmetal lining then as grinding aid and refrigerant the atrament that solidifies with semimetallic lustre with gained.The product that is obtained is the technical grade vanadium pentoxide powder, and it comprises some chromium, iron and manganese as major impurity.
The rich metal chloride wastes solution of the electrolysis of the rich ferrous solution of the no vanadium of embodiment 4-will remove vanadium by the magnesium oxide that adds trace during embodiment 4 is adjusted in pH value 0.9, and makes it the cathodic compartment internal recycling at electrolyzer.Its composition before electrolysis provides at last row of table 4.That describes among electrolyzer and embodiment 2a and the 2b is identical.Also with 200A/m
2Current density continuous current ground carry out electrolysis.Service temperature is that the volumetric flow rate of 85 ℃ and catholyte and anolyte all is 1L/min.Under this current density, total cell voltage of measurement is 1.85V.After five hours continuous electrolysis, cut off the electricity supply and open electrolyzer.By mechanical process easily from the galvanic deposit thin plate of titanium cathodic disbonding ferrous metal.Thickness is that 0.126mm and its quality are the 10.20g (see figure 9)s.It is smooth and the softish material, has some pitfalls, may be owing to the bubble hydrogen that adheres to.From these experimental results, the faradaic current efficient of estimation is 97.9% and at 200A/m
2Under specific energy consumption only be 1.87kWh/kg iron.The purity of iron is 99.99wt.% Fe, does not have other metallic element of trace.
Embodiment 6
The electrolysis of rich metal chloride wastes solution in three compartment electrolyzers-simply is adjusted in pH value 1.1 by the rich metal chloride wastes strong solution that the magnesium oxide that adds trace will derive from embodiment 1, makes it the central compartment's internal recycling at electrolyzer then.Electrolyzer is made of the pressure filter Design Mode MP battery that derives from Electrocell AB (Sweden), its have by anion-exchange membrane (
I-100) and cationic exchange membrane (
I-200) three compartments of Fen Geing, described exchange membrane is all made by SnowPure LLC..Electrode and film geometrical surface are 100cm
2, the spacing of each electrode and spacer is 6mm, the spacing of each film also is 6mm.
Cathodic compartment comprises by titanium palldium alloy (ASTM grade 7; Ti-0.15Pd) negative plate of making, this titanium palldium alloy is provided by Titanium Industries.Before electrolysis, by negative electrode being immersed fluoro-nitrate mixture (the dense HNO of 70vol%
3, the dense HF of 20vol% and 10vol%H
2O), up hill and dale its is washed up to there not being the sour residual of trace with deionized water then with its chemical erosion.
Anode (the DSA of the dimensional stabilizing that is provided by Magneto BV (Netherlands) is provided anodal compartment
TM), it is by scribbling high loading ruthenium dioxide (RuO
2) titanium-palldium alloy base material (Ti-0.15Pd/RuO
2) plate make, ruthenium dioxide serves as eelctro-catalyst and is used to promote emitting of chlorine.
Catholyte with circuit cycle in cathodic compartment is the aqueous solution that is adjusted in pH value 1.1 of 350g/L iron(ic) chloride (II) and 300g/L magnesium chloride (II), and in anodal compartment with the anolyte of circuit cycle by 20wt.% hydrochloric acid and 17wt.% magnesium chloride (MgCl
2) and 10,000ppm is as the ferric iron (Fe of inhibiter
3+) and the aqueous solution of surplus deionized water constitute.
With 500A/m
2Current density continuous current ground carry out electrolysis.Service temperature is that the volumetric flow rate of 80 ℃ and catholyte, anolyte and initial soln all is 1L/min.Under this current density, total cell voltage of measurement is 3.502V.During electrolysis, the ferrous positively charged ion of rich metal chloride wastes solution passes
The I-100 cationic exchange membrane, and the pure iron metal deposition is in negative electrode.On the other hand, cl anion discharges as chlorine towards the migration of anode compartment and in the anodic surface through seeing through anionic exchange membrane.
After two hours continuous electrolysis, cut off the electricity supply and open electrolyzer.By mechanical process easily from the bright ferrous metal settling plate of titanium cathodic disbonding.The thickness of measuring is that about 0.126mm and its quality are the 10.04g (see figure 10)s.From these experimental results, the faradaic current efficient of estimation is 96.4% and at 500A/m
2Under specific energy consumption be 3.485kWh/kg iron.Reclaim chlorine by the means of having described among the embodiment 2a.
Also by standard method following recovery vanadium from the poor ferrous solution that leaves central compartment.Sodium chlorate (NaClO with stoichiometry
3) add in this poor ferrous solution with according to following reaction with all vanadium positively charged ion (V
4+, V
5+) be oxidized to pentavalent vanadium (V
5+):
5VO
2++ClO
3 -+2H
2O→5VO
2 ++0.5Cl
2(g)+4H
+。
Then, by the loose magnesium oxide of careful interpolation (Mg (OH)
2) the slurry pH value that improves solution reach 2.0 up to pH value, still be no more than 2.0 to avoid the precipitation of the ferrous-iron hydroxide of black mixing.Under this pH value, hydration Vanadium Pentoxide in FLAKES (V
2O
5250H
2O) complete throw out occurs with gel reddish-brown precipitation form.Because vanadium is unique sedimentary material in this case, thus precipitation will be in this solution vanadium concentration stop during less than about 0.02mol/L.The reconcentration of solution can reclaim more vanadium.
By use with embodiment 4 describe similar be provided with to filter separate this reddish-brown precipitation thing.Take off this sorrel gel filter cake and dry to the baking oven from filter paper, after a while in porcelain boat inside in dry air under 400 ℃ in box-type furnace (Fisher Isotemp) roasting with release water vapour (H
2O), thus produce the red-orange powder of Vanadium Pentoxide in FLAKES.Then with this powder transfer in the lnconel crucible, fusion in air under 700 ℃, and curtain coating is on cold steel plate.Use acetone to be ground in the two disc vibration cup shredders (Fritsch GmbH) with hardmetal lining then as grinding aid and refrigerant the atrament that solidifies with semimetallic lustre with gained.The product that is obtained is the technical grade vanadium pentoxide powder, and it comprises some chromium, iron and manganese as major impurity.
Some results and the feature of the electrolytic experiment that carries out among embodiment 2a, the 2b, 5 and 6 are summarised in the following table 5.
Embodiment 7
Remove calcium from poor electrolytic iron liquid.-embodiment 2a, 2b, 5 and 6 each after, with the vitriol oil add to the poor iron that leaves electrolyzer and solution that may poor vanadium with calcium as sedimentary insoluble calcium sulfate dihydrate (CaSO
42H
2O) remove.By removing by filter throw out.This only contains magnesium and/or the muriatic settled solution of aluminium prepares to be used for pyrohydrolysis.
Embodiment 8
The selection of cathode material is carried out in identical electrolyzer and the setting carrying out among embodiment 2a, the 2b, 5 and 6 using among the selection of electrolytic cathode material-use and the embodiment 2a, different being to use with circuit cycle and the composite cathode electrolytic solution that constitutes by the aqueous solution that is adjusted in pH value 1.1 of 350g/L iron(ic) chloride (II) and 300g/L magnesium chloride (II), and with the anolyte of circuit cycle by 20wt.% hydrochloric acid and 17wt.% magnesium chloride (MgCl
2) and 10,000ppm is as the ferric iron (Fe of inhibiter
3+) and the aqueous solution of surplus deionized water constitute.Under 80 ℃ during two hours continuous current carry out electrolysis.For each cathode material record polarization curve, i.e. cell voltage vs. current density.The material of being tested is titanium-palldium alloy ASTM grade 7 (Ti-0.15Pd) of deriving from Titanium Industries, derives from Wah Chang's
702, austenitic stainless steel AISI grade 316L, aluminium class 6 061 T6 and fine copper.As expected, only titanium and zirconium allow peeling off easily of deposition of iron thing.Polarization curve provides in Figure 11.
Embodiment 9
The selection of anion-exchange membrane is carried out in identical electrolyzer and the setting carrying out among embodiment 2a, the 2b, 5 and 6 using among the selection of electrolytic anion-exchange membrane-use and the embodiment 2a.In cathodic compartment, constitute with the composite cathode electrolytic solution of circuit cycle the aqueous solution that is adjusted in pH value 1.1 by 350g/L iron(ic) chloride (II) and 300g/L magnesium chloride (II), and in anodal compartment with the anolyte of circuit cycle by 20wt.% hydrochloric acid and 17wt.% magnesium chloride (MgCl
2) and 10,000ppm is as the ferric iron (Fe of inhibiter
3+) and the aqueous solution of surplus deionized water constitute.Under 80 ℃ during two hours continuous current carry out electrolysis.For each anion-exchange membrane record polarization curve, i.e. cell voltage vs. current density.The film of test is
I-100 (SnowPure LLC),
AMH, ACM and AHA (Tokuyama Co.Ltd.-Eurodia), Selemion (AsahiGlass) and
AMI-7001 (Membrane International).Polarization curve provides in Figure 12.
The selection of anolyte is carried out in identical electrolyzer and the setting carrying out among embodiment 2a, the 2b, 5 and 6 using among the selection of the composition of electrolytic anolyte-use and the embodiment 9, the different composite cathode electrolytic solution that are to use in cathodic compartment the aqueous solution that is adjusted in pH value 1.1 with circuit cycle to constitute by 350g/L iron(ic) chloride (II) and 300g/L magnesium chloride (II), in anodal compartment with the variation composed as follows of the anolyte of circuit cycle: (i) 20wt.%MgCl
2+ 2wt.%HCl; (ii) 20wt.%MgCl
2+ 5wt.%HCl; (iii) 17wt.%MgCl
2+ 20wt.%HCl; (iv) 20wt.%HCl contains 10, and 000ppm wt.Fe (III) is as inhibiter.Under 80 ℃ during two hours continuous current carry out electrolysis.For each anode electrolysis fluid composition record polarization curve, i.e. cell voltage vs. current density.Polarization curve provides in Figure 13.
Though above describing the present invention, can under the situation that does not break away from the spirit of the present invention that limits in the appended claims and character, make improvements via particular of the present invention.
Reference
1HARRIS，et?al.-Process?for?chlorination?of?titanium?bearing?materials?and?fordechlorination?of?iron?chloride.-in?WEISS，A.(ed)(1976)-World?Miningand?Metals?Technology.-The?Society?of?Mining?Engineers，New?York，Chap.44，pages?693-712
2Gray，D.A.and?Robinson，M.-Process?for?the?Recovery?of?Chlorine.-G.B.Pat.1,407,034；Sept.24，1975
3DUNN，W.E.(Rutile&Zircon?Mines?Ltd.)-Process?for?Beneficiating?andTitanoferrous?Ore?and?Production?of?Chlorine?and?Iron?Oxide.-U.S.Pat.3,865,920；Feb.11，1975
4WALSH，R.H.(Columbia?Southern?Chemical?Gorp.)-Metal?ChlorideManufacture.-U.S.Pat.2,954,274；Sept.27，1960
5REEVES，J.W.et?al.(E.I.Du?Pont?de?Nemours)-Multistage?iron?chlorideoxidation?process.-U.S.Pat.3,793,444；Feb.19，1974
6HAACK，D.J.；and?REEVES，J.W.(E.I.Du?Pont?de?Nemours?Company)-Production?of?chlorine?and?iron?oxide?from?ferric?chloride.-US?Patent4,144,316；March?13，1979
7REEVES，J.W；SYLVESTER，R.W；and?WELLS，D.F.(E.I.DU?Pont?deNemours?Company)-Chlorine?and?iron?oxide?from?ferric?chloride-apparatus.-US?Patent?4,282,185；August?04，1981
8HSU，C.K(SCM?Chemicals)-Oxidation?of?ferrous?chloride?directly?to?chlorinein?a?fluid?bed?reactor.-US?Patent?4,994,255；February?19，1991
9HARTMANN；A.；KULLING；A.；and?THUMM；H.(Kronos?Titan?GmbH)-Treatment?of?iron(ii)chloride.-US?Patent?4,060,584；November?29，1977
10HOOPER，B.N.；HIRSCH，M.；ORTH，A.；BENNETT，B.；DAVIDSON，J.F.；CONDUIT，M.；FALLON，N.；and?DAVIDSON，P.J.(Tioxide?Group?Ltd.)-Treatment?of?iron?chloride?from?chlorination?dust.-US?Patent?6,511,646；January?01，2003
11LEVY，I.S.-Electrolysis?of?ferrous?chloride.-US?Patent?1,752,348；April?1，1930
12OGASAWARA.T.；FUJITA，K.；and?NATSUME，Y.(Osaka?Titanium)-Production?of?iron?and?chlorine?from?aqueous?solution?containing?ironchloride.-Japanese?Patent?02-015187；January?18，1990
13CARDARELLI，F.Materials?Handbook：a?Concise?Desktop?Reference.Springer-Verlag?London?Limited?[Ed.].2000.p.323
14GREANEY，M.A.-Method?for?Demetallating?Petroleum?Streams(LAW?639)-U.S.Patent?5,911,869；June?15，1999
Claims (65)
1. reclaim the electrochemical method of metallic iron and chlorine from rich metal chloride wastes solution, this method comprises:
A) provide rich metal chloride wastes solution;
B) in electrolyzer with the described rich metal chloride wastes electrolysis of solutions, described electrolyzer comprises: be equipped with the hydrogen overpotential than the high negative electrode of iron and comprise the cathodic compartment of pH value less than 2 catholyte, be equipped with anode and comprise the anodal compartment of anolyte, with the spacer that allows negatively charged ion to pass through, described electrolysis step comprises circulates described rich metal chloride wastes solution in the non-anodal compartment of described electrolyzer, thereby make the ferroelectric negative electrode and chlorine is emitted at anode of being deposited on, stay poor ferrous solution; With
C) reclaim the iron and the described chlorine of described galvanic deposit respectively.
2. the electrochemical method of claim 1 wherein provides the step a) of rich metal chloride wastes solution may further comprise the steps:
A1), thereby form aqueous slurry with hot aqueous solution lixiviate solid carburizing chlorination waste material; With
A2) to described aqueous slurry carry out solids constituent from, thereby form insoluble cake and isolate rich metal chloride wastes solution.
3. according to the electrochemical method of claim 1, wherein the pH value with catholyte is adjusted to 0.3-1.8.
4. according to the electrochemical method of claim 3, wherein the pH value with catholyte is adjusted to 0.6-1.5.
5. according to the electrochemical method of claim 3, wherein the pH value with catholyte is adjusted to 0.6-1.1.
6. according to the electrochemical method of claim 3, wherein the pH value with catholyte is adjusted to 0.9-1.1.
7. according to each electrochemical method among the claim 1-6, wherein negative electrode is at 0.5moldm
-3Among the HCl, at 25 ℃, 200Am
-2Has superpotential greater than 425mV.
8. according to the electrochemical method of claim 7, wherein negative electrode is configured to or applies by being selected from following material: titanium, titanium alloy, zirconium, zirconium alloy, zinc, zinc alloy, cadmium, cadmium alloy, tin, tin alloy, copper, copper alloy, lead, lead alloy, niobium, niobium alloy, gold, au-alloy, mercury and mercurous metallic amalgam.
9. electrochemical method according to Claim 8, wherein said material is made of titanium or titanium alloy.
10. according to the electrochemical method of claim 9, wherein said material is made of titanium palladium ASTM grade 7.
11. according to each electrochemical method among the claim 1-6, wherein before electrolysis step with the negative electrode pre-treatment.
12. according to the electrochemical method of claim 11, wherein before electrolysis step with negative electrode by immersing chemical erosion in the fluoro-nitrate mixture, and with the deionized water cleaning down to remove the acid of trace.
13. according to the electrochemical method of claim 12, wherein said fluoro-nitrate mixture has the dense HNO of following composition: 70vol%
3, dense HF of 20vol% and 10vol%H
2O.
14. according to each electrochemical method among the claim 1-6, wherein said anolyte in the anodal compartment of electrolyzer with circuit cycle.
15. according to each electrochemical method among the claim 1-6, wherein said anolyte comprises HCl, is selected from MgCl
2, NaCl, LiCl, KCl, CaCl
2With they mixture salt and as the iron (III) of inhibiter.
16. according to the electrochemical method of claim 15, wherein said anolyte comprises 10-37wt.%HCl.
17. according to the electrochemical method of claim 15, wherein said anolyte comprises 20%HCl.
18. according to the electrochemical method of claim 15, wherein said anolyte comprises 1-20wt.% and is selected from MgCl
2, NaCl, LiCl, KCl, CaCl
2With their salt of mixture.
19. according to the electrochemical method of claim 15, wherein said anolyte comprises 16wt.% and is selected from MgCl
2, NaCl, LiCl, KCl, CaCl
2With their salt of mixture.
20. according to the electrochemical method of claim 15, wherein said anolyte comprises 10-12,000ppm wt is as the iron (III) of inhibiter.
21. according to the electrochemical method of claim 15, wherein said anolyte comprises the iron (III) of 8000-10000ppm wt as inhibiter.
22. according to the electrochemical method of claim 15, wherein said anolyte comprises 10-37wt.%HCl, 1-20wt.% is selected from MgCl
2, NaCl, LiCl, KCl, CaCl
2With their salt of mixture, and 10-12,000ppm wt is as the iron (III) of inhibiter.
23. according to the electrochemical method of claim 22, wherein said anolyte comprises 20%HCl.
24. according to the electrochemical method of claim 22, wherein said anolyte comprises 16wt.% and is selected from MgCl
2, NaCl, LiCl, KCl, CaCl
2With their salt of mixture.
25. according to the electrochemical method of claim 22, wherein said anolyte comprises the iron (III) of 8000-10000ppm wt as inhibiter.
26. according to each electrochemical method among the claim 1-6, wherein anode is [M/M
xO
y-A
zO
t] dimensionally stable anode of type, wherein M is refractory metal or alloy with valve action performance, comprises titanium, titanium alloy, zirconium, zirconium alloy, hafnium, hafnium alloy, vanadium, vanadium alloy, niobium, niobium alloy, tantalum or tantalum alloy, wherein M
xO
yBe the metal oxide of valve metal, it forms the impermeable thin layer of protecting group substrate, comprises TiO
2, ZrO
2, HfO
2, NbO
2, Nb
2O
5, TaO
2Or Ta
2O
5And A wherein
zO
tIt is the electrocatalysis metal oxide of precious metal.
27. according to each electrochemical method among the claim 1-6, wherein anode is [M/M
xO
y-A
zO
t] dimensionally stable anode of type, wherein M is refractory metal or alloy with valve action performance, comprises titanium, titanium alloy, zirconium, zirconium alloy, hafnium, hafnium alloy, vanadium, vanadium alloy, niobium, niobium alloy, tantalum or tantalum alloy, wherein M
xO
yBe the metal oxide of valve metal, it forms the impermeable thin layer of protecting group substrate, comprises TiO
2, ZrO
2, HfO
2, NbO
2, Nb
2O
5, TaO
2Or Ta
2O
5And A wherein
zO
tBe the oxide compound of platinum metals, comprise RuO
2, IrO
2Or P
tO
x
28. according to each electrochemical method among the claim 1-6, wherein anode is [M/M
xO
y-A
zO
t] dimensionally stable anode of type, wherein M is refractory metal or alloy with valve action performance, comprises titanium, titanium alloy, zirconium, zirconium alloy, hafnium, hafnium alloy, vanadium, vanadium alloy, niobium, niobium alloy, tantalum or tantalum alloy, wherein M
xO
yBe the metal oxide of valve metal, it forms the impermeable thin layer of protecting group substrate, comprises TiO
2, ZrO
2, HfO
2, NbO
2, Nb
2O
5, TaO
2Or Ta
2O
5And A wherein
zO
tBe metal oxide, comprise SnO
2, Sb
2O
5Or Bi
2O
3
29. according to each electrochemical method among the claim 1-6, wherein anode is configured to by following material: body electroconductibility pottery comprises having general formula Ti
nO
2n-1The substoichiometric titanium oxide, wherein n is equal to or greater than 3 integer; Has spinel structure AB
2O
4Electroconductive oxide, wherein A is Fe (II), Mn (II) or Ni (II), B is Al, Fe (III), Cr (III) or Co (III); Or has a perovskite structure ABO
3Electroconductive oxide, wherein A is Fe (II), Mn (II), Co (II) or Ni (II), B is Ti (IV), or has pyrochlore constitution AB
2O
7Electroconductive oxide.
30. according to each electrochemical method among the claim 1-6, wherein anode is configured to by carbon-based material.
31. according to the electrochemical method of claim 30, wherein anode is configured to by graphite.
32. according to the electrochemical method of claim 30, wherein anode is configured to by impervious graphite.
33. according to the electrochemical method of claim 30, wherein anode is configured to by vitreous carbon.
34. according to each electrochemical method among the claim 1-6, wherein electrolysis step therebetween parting be to carry out in the two compartment electrolyzers of ion-exchange membrane, and wherein said rich metal chloride wastes solution in the cathodic compartment of this electrolyzer with circuit cycle, serve as catholyte.
35. according to the electrochemical method of claim 34, wherein said spacer is an anion-exchange membrane.
36., wherein before electrolysis step, the pH value of rich metal chloride wastes solution is adjusted to less than 2 according to the electrochemical method of claim 34.
37. according to the electrochemical method of claim 36, wherein before electrolysis step, with the pH regulator of rich metal chloride wastes solution to 0.3-1.8.
38. according to the electrochemical method of claim 36, wherein before electrolysis step, with the pH regulator of rich metal chloride wastes solution to 0.6-1.5.
39. according to the electrochemical method of claim 36, wherein before electrolysis step, with the pH regulator of rich metal chloride wastes solution to 0.6-1.1.
40. according to the electrochemical method of claim 36, wherein before electrolysis step, with the pH regulator of rich metal chloride wastes solution to 0.9-1.1.
41. according to each electrochemical method among the claim 1-6, wherein the volumetric flow rate of anolyte and catholyte all is 0.1L/min-100L/min.
42. according to the electrochemical method of claim 41, wherein the volumetric flow rate of anolyte and catholyte all is 0.1L/min-30L/min.
43. according to the electrochemical method of claim 41, wherein the volumetric flow rate of anolyte and catholyte all is 2L/min.
44. according to each electrochemical method among the claim 1-6, wherein electrolysis step under constant current with 50-5000A/m
2Current density carry out.
45. according to the electrochemical method of claim 44, wherein electrolysis step under constant current with 50-1000A/m
2Current density carry out, thereby obtain the smooth settling of the essentially no dentrite of iron.
46. according to the electrochemical method of claim 45, wherein electrolysis step under constant current with 500A/m
2Current density carry out, thereby obtain the smooth settling of the essentially no dentrite of iron.
47. according to the electrochemical method of claim 44, wherein electrolysis step under constant current with 3000-5000A/m
2Current density carry out, thereby obtain powdered iron basically.
48. according to the electrochemical method of claim 44, wherein electrolysis step under constant current with 4000A/m
2Current density carry out, thereby obtain powdered iron basically.
49. according to each electrochemical method among the claim 1-6, wherein electrolysis step is carried out under 40-110 ℃ service temperature.
50. according to the electrochemical method of claim 49, wherein electrolysis step is carried out under 80 ℃-95 ℃ service temperature.
51. according to the electrochemical method of claim 49, wherein electrolysis step is carried out under 85 ℃ the service temperature equaling.
52. according to the electrochemical method of claim 1, wherein rich metal chloride wastes solution comes from carburizing chlorination waste material, spent acid leaching liquid or pickle solution.
53. according to each electrochemical method among the claim 1-6, wherein rich metal chloride wastes solution comprises vanadium, described method also is included in before the electrolysis step, during or vanadium separating step afterwards.
54. according to the electrochemical method of claim 53, wherein said vanadium separating step carried out before electrolysis step.
55. according to the electrochemical method of claim 54, wherein said vanadium separating step relates under the pH of 0.5-3.0 value removes vanadium and chromium simultaneously by co-precipitation from rich metal chloride wastes solution.
56. according to the electrochemical method of claim 53, wherein the pH value of catholyte is 0.3-0.5, thus make vanadium along with the electro-deposition of iron at cathode deposition, and wherein the vanadium separating step carries out after electrolysis step.
57. electrochemical method according to claim 53, wherein the pH value of catholyte is 0.6-1.8, thereby vanadium is remained essentially in the round-robin rich metal chloride wastes solution at iron, and after this reclaiming vanadium from the poor ferrous solution that leaves electrolyzer, the vanadium separating step carries out during electrolysis step by this.
58. according to each electrochemical method among the claim 1-6, wherein will further dry and liquefaction from the chlorine that anode reclaims.
59. according to each electrochemical method among the claim 1-6, wherein reclaim the poor ferrous solution that leaves electrolyzer and further handle removing calcium and radioactive substance, thereby produce the salt solution of rich magnalium by adding sulfuric acid.
60. according to the method for claim 59, also be included in the brinish step of the described rich magnalium of pyrohydrolysis in the fluidized-bed pyrohydrolysis device, thereby produce azeotropic hydrochloric acid and spinel pearl.
61., comprise that also reclaiming described azeotropic hydrochloric acid is used for output according to the method for claim 60.
62. according to the method for claim 2, wherein useless lixiviate acid or the waste pickle liquor with thermal process water, hot dilute hydrochloric acid, heat carries out lixiviate.
63., wherein carry out the solid separating step by physical separation method according to the method for claim 2.
64., wherein carry out the solid separating step by decantation, filtration or centrifugation according to the method for claim 63.
65. from the electrochemical method of rich metal chloride wastes solution recovery metallic iron and chlorine, this method comprises:
A) provide rich metal chloride wastes solution;
B) the described rich metal chloride wastes solution of electrolysis in two compartment electrolyzers, described two compartment electrolyzers comprise: be equipped with the cathodic compartment of the hydrogen overpotential negative electrode higher than iron and be equipped with anode and comprise the anodal compartment of anolyte, described negative electrode and anodal compartment are separated by anion-exchange membrane, described electrolysis step comprises making and is adjusted to the pH value and circulates in the described cathodic compartment of described electrolyzer as catholyte less than 2 described rich metal chloride wastes solution, thereby make iron at cathode electrodeposition and chlorine is emitted at anode, stay poor ferrous solution; With
C) reclaim the iron and the described chlorine of described galvanic deposit respectively, wherein, undertaken that iron reclaims and carry out chlorine by suction chlorine above anodal compartment and reclaim by peel off described iron with physics mode at cathode electrodeposition.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US82645306P | 2006-09-21 | 2006-09-21 | |
| US60/826,453 | 2006-09-21 | ||
| CA2,560,407 | 2006-09-21 | ||
| CA2560407 | 2006-09-21 | ||
| PCT/CA2007/000026 WO2008034212A1 (en) | 2006-09-21 | 2007-01-09 | Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101517129A CN101517129A (en) | 2009-08-26 |
| CN101517129B true CN101517129B (en) | 2011-05-11 |
Family
ID=41040522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007800350588A Expired - Fee Related CN101517129B (en) | 2006-09-21 | 2007-01-09 | Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN101517129B (en) |
| AT (1) | ATE503864T1 (en) |
| DE (1) | DE602007013578D1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102091527A (en) * | 2010-12-23 | 2011-06-15 | 何卫东 | Method and device for absorbing waste chlorine generated in lithium production process by utilizing iron powder |
| CN102633326B (en) * | 2012-04-28 | 2014-05-21 | 云南铜业股份有限公司 | Ion exchange membrane electrolysis method for treating acid waste water containing chloride in copper metallurgy process |
| CN108505061A (en) * | 2018-07-03 | 2018-09-07 | 中国水利水电科学研究院 | A kind of high-concentrated sodium hypochlorite generator |
| CN109182782B (en) * | 2018-09-25 | 2020-12-04 | 内蒙古扎鲁特旗鲁安矿业有限公司 | Boiling chlorination extraction method of niobium-tantalum concentrate |
| CN109136985A (en) * | 2018-10-27 | 2019-01-04 | 揭阳市斯瑞尔环境科技有限公司 | A kind of method that electrolytic chlorination iron etching waste liquor produces iron plate and ferric trichloride |
| CN110592378B (en) * | 2019-04-30 | 2021-05-04 | 内蒙古科技大学 | Method for recovering rare earth and iron from ultrafine powder waste generated in neodymium iron boron production process |
| CN111663039B (en) * | 2020-06-01 | 2022-07-12 | 中国恩菲工程技术有限公司 | Method and apparatus for recovering polymetallic nodules |
| CN115645814B (en) * | 2022-10-27 | 2024-04-05 | 浙江工业大学 | Ultralow-load palladium nanocrystal modified electrode, preparation method thereof and application thereof in electrochemical dechlorination |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995023880A1 (en) * | 1994-03-04 | 1995-09-08 | Spunboa Pty. Limited | Treatement of electrolyte solutions |
| US5954854A (en) * | 1996-06-28 | 1999-09-21 | Astec Irie Co., Ltd. | Method for recovering etchant from etching waste liquid containing iron chloride |
-
2007
- 2007-01-09 AT AT07701657T patent/ATE503864T1/en not_active IP Right Cessation
- 2007-01-09 CN CN2007800350588A patent/CN101517129B/en not_active Expired - Fee Related
- 2007-01-09 DE DE602007013578T patent/DE602007013578D1/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995023880A1 (en) * | 1994-03-04 | 1995-09-08 | Spunboa Pty. Limited | Treatement of electrolyte solutions |
| US5954854A (en) * | 1996-06-28 | 1999-09-21 | Astec Irie Co., Ltd. | Method for recovering etchant from etching waste liquid containing iron chloride |
Non-Patent Citations (2)
| Title |
|---|
| JP平2-15187A 1990.01.18 |
| JP平2-26802A 1990.01.29 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101517129A (en) | 2009-08-26 |
| ATE503864T1 (en) | 2011-04-15 |
| DE602007013578D1 (en) | 2011-05-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102037160B (en) | Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes | |
| EP2064369B1 (en) | Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes | |
| CN101517129B (en) | Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes | |
| EP2268852B1 (en) | Electrochemical process for the recovery of metallic iron and sulfuric acid values from iron-rich sulfate wastes, mining residues and pickling liquors | |
| CA2535978C (en) | Thermal and electrochemical process for metal production | |
| EP2109691B1 (en) | Metallothermic reduction of in-situ generated titanium chloride | |
| RU2518839C2 (en) | Processing of titanium ores | |
| AU2018225820A1 (en) | Metallurgical and chemical processes for recovering vanadium and iron values from vanadiferous titanomagnetite and vanadiferous feedstocks | |
| Haver et al. | Improvements in ferric chloride leaching of chalcopyrite concentrate | |
| NO792977L (en) | PROCEDURE FOR REDUCING IRONS | |
| US4632738A (en) | Hydrometallurgical copper process | |
| EP0935005B1 (en) | Process for treating metallic dust, mostly oxididised waste, in particular galvanising dust and/or steelworks smoke | |
| CN109763141B (en) | Multi-metal leaching and recycling process | |
| Withers et al. | The electrolytic production of Ti from a TiO2 feed (the DARPA sponsored program) | |
| IT202000002515A1 (en) | METHOD FOR RECOVERING METALLIC ZINC FROM METALLURGIC WASTE. | |
| RO107136B1 (en) | Electrochemical preparation process for chromic acid | |
| Lefebvre et al. | ELECTROLYTIC RECOVERY OF METALLIC IRON AND CHLORINE GAS FROM CHLORIDE WASTE | |
| US2741590A (en) | Electrolytic recovery of manganese | |
| US1201541A (en) | Method of obtaining titanic oxid. | |
| JPH0226802A (en) | Method for recovering metal chloride | |
| JPS6033769B2 (en) | Ilmenite smelting method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110511 Termination date: 20130109 |