CN101437758A - Method of reducing calcia concentrations of green Bayer process liquors - Google Patents
Method of reducing calcia concentrations of green Bayer process liquors Download PDFInfo
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- CN101437758A CN101437758A CN200780016077.6A CN200780016077A CN101437758A CN 101437758 A CN101437758 A CN 101437758A CN 200780016077 A CN200780016077 A CN 200780016077A CN 101437758 A CN101437758 A CN 101437758A
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- phosphatic rock
- solution
- red mud
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/32—Phosphates of magnesium, calcium, strontium, or barium
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
- C01F7/062—Digestion
- C01F7/0633—Digestion characterised by the use of additives
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
- C01F7/0646—Separation of the insoluble residue, e.g. of red mud
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/46—Purification of aluminium oxide, aluminium hydroxide or aluminates
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Abstract
A method of reducing the calcia concentration of a green Bayer process liquor containing calcia and phosphate, the method comprising the step of: contacting the green Bayer process liquor with a quantity of apatite; thereby inducing the precipitation of further apatite and reducing the calcia concentration of the green Bayer process liquor.
Description
Technical field
The present invention relates to reduce the method for calcium oxide concentration in the solution that produces when from aluminium ore, producing aluminum oxide by Bayer process.Especially, the present invention relates to reduce the method for calcium oxide concentration in the unprocessed bayer liquors (green Bayer processliquors).
Background technology
Bayer process is widely used in producing aluminum oxide from salic ore (for example, bauxite).At first in being commonly referred to as the technology of stripping, under elevated temperature, the ore that will contain aluminum oxide contacts with the regenerated sodium aluminate solution this method.
After the stripping, the insoluble red mud in the sodium aluminate solution (unprocessed solution) is starched a series of decompressions jar (being known as blowdown vessel) of flowing through, and this solution is reduced to normal atmosphere suddenly at this jar place.In this method next step is that insoluble red mud is separated from sodium aluminate solution.Thick material may be removed in being known as the crude oil swirler of sand-settling device, and thin residue is stayed in the rake thickener after adding synthetic flocculant.Red mud is taken as the underflow of thickner, and common then flushing red mud is to recover the alkalescence value and to make it be suitable for handling.Yet overflow still contains superfine red mud particle usually, comprises ferric oxide, ironic hydroxide, silicon-dioxide etc.The existence of these compounds in the aluminum oxide end product do not expect that very the one or more strainers of the common process of sedimentation tank overflow are to remove them.
Clear soln is further cooled off in heat exchanger, and this improves the degree of supersaturation of dissolved aluminum oxide, and solution is pumped to settling vessel and sows to induce more aluminum hydroxide precipitation with aluminium hydroxide then.Isolate sedimentary aluminium hydroxide from sodium aluminate solution, a part of aluminium hydroxide is recycled as crystal seed, and residuum is recovered as product.Remaining sodium aluminate solution is recycled the further stripping that is used for salic ore.
Dissolving-out process consumes oxyhydroxide, and it replenishes (to small part) usually again by adding lime.The calcium oxide that mode by lime is introduced into is can calcium carbonate form precipitated.Yet, can realize more effective causticization by adding excessive lime, this means that the calcium oxide concentration in the solution increases.
Obviously, for effective precipitation, wish very much to want high with respect to total alkali concn alumina concentration.Yet, do not wish that equally any aluminum oxide of dissolved precipitates before filtration.Except lowering efficiency, this has reduced the time that the strainer maintenance can be turned round.The maintenance needs of strainer depends on employed filter type, opens filter assemblies, removes solid and with the cleaning waste liquid filter media that backwashes but generally include.This causes sizable interference to most of continuous processing in addition, and needs considerable work.Therefore, most of refineries usually determine the critical ratio of an alumina concentration and total alkali concn, are higher than this value and then filter and just become infeasible.For example by adding lime or calcite, perhaps in other cases, for example organic concentration raises in the solution, and/or for example side effect of other factory technics, the rising of unprocessed solution (or slurries) calcium oxide concentration has increased the stability of aluminum oxide, filters under the ratio of higher aluminum oxide/total alkali (caustic) with permission.
Yet calcium oxide concentration height can show the problem of a product quality in the solution: calcium oxide is removed quantitatively by hydration precipitation, and is retained by calcining, makes in the solution that about 100% calcium oxide finally is reported as the product aluminum oxide.Therefore, the technology that those cause calcium concn in the solution to improve is for example used the stabilization and the causticization (causticisation) of the aluminum oxide of superfluous lime, can not bring into play fully they potential and not negative impact product quality.
Therefore, be starved of the method that some reduce calcium oxide in the bayer liquors.
Background of the present invention previously discussed is intended to help to understand the present invention.Yet, should be appreciated that this discussion be not think or when admitting that any indication content is priority date in Australian conventional knowledge.
Summary of the invention
It will be appreciated by those skilled in the art that invention described herein is easy to change and the modification except that the content that specifies.Should understand and the present invention includes all such changes and modifications.The present invention also comprise indication in the specification sheets or the institute that hinted in steps, feature, composition and compound, and with separately or integrally and the mode of any and all combinations of any two or more steps or feature.
The invention is not restricted to the scope of embodiment as herein described.They only are used for the purpose of illustration.
The product of function equivalent, composition and method are obviously within the scope of the invention.
Whole disclosures of all publications that this paper quotes (comprising patent, patent application, magazine article, laboratory operation guide, book or other file) are introduced into this paper as a reference at this.
In the whole specification sheets, unless context has needs in addition, word " all comprises " or its distortion " comprises " or " having comprised " will be understood that to hint and comprise pointed whole or whole collection and do not get rid of any other whole or whole collection.
In the whole specification sheets, unless context has needs in addition, word " phosphatic rock " refers to based on hydroxylapatite (Ca
10(PO
4)
6OH
2) a compounds in one or more, comprise fluorapatite (Ca
10(PO
4)
6F
2), chlorapatite ((Ca
10(PO
4)
6Cl
2), hydroxylapatite (Ca
10(PO
4)
6OH
2), phosphatic rock carbonate, hydroxylapatite carbonate or fluorapatite carbonate.The phosphatic rock of most forms can pass through following general formula A
10(XO
4)
6(OH, F, Cl)
2.NH
2O describes, and wherein: A can be selected from Ba, Ca, Ce, K, Na, Pb, Sr, Y; X can be selected from As, P, Si, V and PO
4Can to small part by CO
3Replace.
In the whole specification sheets, unless context has needs in addition, word " phosphatic rock " has comprised the mixture that contains phosphatic rock, and it comprises the mixture that contains one or more phosphatic rock.
According to the present invention, provide and reduce the method that contains calcium oxide concentration in calcium oxide and the phosphatic unprocessed bayer liquors, this method comprises the steps:
Unprocessed bayer liquors is contacted with a certain amount of phosphatic rock;
Thereby impel the precipitation of further phosphatic rock and reduce the concentration of calcium oxide in the unprocessed bayer liquors.
Phosphatic rock can have following general formula A
10(XO
4)
6(OH, F, Cl)
2NH
2Any compound form of O provides, and wherein: A can be selected from Ba, Ca, Ce, K, Na, Pb, Sr, Y; X can be selected from As, P, Si, V and PO
4Can be by CO
3Replace.
Preferably, A is that Ca and Na and phosphatic rock at least mainly provide with hydroxylapatite carbonate or with any mixture of this compound, and this hydroxylapatite carbonate has general formula Ca
10-xNa
2x/3(PO
4)
6-x(CO
4)
x(OH)
2-x/3XH
2O, wherein, 0≤x≤3.
A kind of form of the present invention, phosphatic rock is with Ca
7Na
2(CO
3)
3(PO
4)
3(H
2O)
3(OH) form provides.
Yet scope of the present invention should not be understood that to be limited to hydroxylapatite carbonate, because verified such as Ca
5(PO
4)
3(OH) hydroxylapatite noncarbonate is effective.
Usually can situ production phosphatic rock in many Bayer process refinery, this provides other advantage of the present invention.
For example, can prepare phosphatic rock by interpolation lime source and phosphate source in bayer liquors.A kind of form of the present invention, the lime source provides with the form of white lime, tricalcium aluminate or filter pressing sludge.Phosphate source and bayer liquors can high phosphate Bayer process waste liquid form provide together.In about 90 ℃ temperature, the residence time that is used to prepare phosphatic rock is very short, about 15-30min.So the phosphatic rock of producing can be separated from this solution before being used for method of the present invention.Perhaps, the slurries of phosphatic rock and upper solution can be used for method of the present invention.
The preparation method that has been found that phosphatic rock influences phosphatic rock effectiveness in the methods of the invention.Particularly, more effective with the phosphatic rock of the excessive phosphoric acid salt of stoichiometry preparation, it is excessive to provide big more effectiveness more at most.Therefore, in the preferred form of the present invention, the phosphoric acid salt excessive with stoichiometry prepares phosphatic rock.Yet the residual phosphate concn of phosphatic rock post precipitation can cause other process complexity.Therefore, in the preferred form of the present invention, use less than the excessive phosphoric acid salt of 200% stoichiometry to prepare phosphatic rock.In the preferred form of the present invention, use less than the excessive phosphoric acid salt of 100% stoichiometry to prepare phosphatic rock.In the preferred form of the present invention, use less than the excessive phosphoric acid salt of 50% stoichiometry to prepare phosphatic rock.
In addition, have been found that phosphatic rock effectiveness in the methods of the invention reduces in time.Therefore, a certain amount of phosphatic rock is preferably newly sedimentary, or at least from will newly being separated its sedimentary solution.In the highly preferred form of the present invention, the method according to this invention, phosphatic rock its with 24h before unprocessed bayer liquors contacts in precipitated.Yet the time, longer phosphatic rock can be used for favourable processing condition, for example, and high density oxidation calcium and phosphatic feed solution.Also preferred, the method according to this invention, phosphatic rock its with 8h before unprocessed bayer liquors contacts in precipitated.
In addition, have been found that sedimentary phosphatic rock can be enhanced by a certain amount of phosphatic rock is exposed in the phosphate solution in the effectiveness of the inventive method.Have been found that replenishing active degree depends on the concentration of phosphate solution and expose the time length, long more and many more the replenishing of the big more then generation of phosphate solution concentration of exposure duration.As an example, chronic phosphatic rock is exposed to activity that the about 15min of 9000ppm phosphate solution will recover phosphatic rock approximately to new sedimentary phosphatic rock active half to 1/3rd.
Having been found that influences the reduction degree of calcium oxide concentration the duration of contact (residence time) of bayer liquors and a certain amount of phosphatic rock, and residence time is long more usually causes the calcium oxide minimizing many more.Therefore, reduce the other factors that combines Bayer process with the effect of the inventive method by balance oxidation calcium and obtain preferred residence time.Yet, use the very short time can realize that also effective calcium oxide reduces, in many preferred implementations of the present invention, the requirement that does not apply extra residence time in conjunction with existing Bayer process step promptly can realize this method.
Have been found that a certain amount of phosphatic rock that joins in the bayer liquors influences the reduction degree of calcium oxide concentration, dosage is big more remarkable more and/or rapid more to the influence that reduces.In addition, different dosage is suitable for different methods that unprocessed bayer liquors is contacted with a certain amount of phosphatic rock.The different methods that unprocessed bayer liquors is contacted with a certain amount of phosphatic rock is discussed below.Yet, should be enough for the scope of treatment condition with the dosage of 200-300mg phosphatic rock/kL bayer liquors magnitude.Lower dosage is possible under favourable treatment condition (for example calcium oxide of high density and phosphatic feed solution).
Have been found that the phosphate concn in the unprocessed bayer liquors influences the reduction degree of calcium oxide concentration, concentration is high more remarkable more and/or rapid to the influence that reduces.Yet as skilled in the art to understand, high phosphate concentration has been introduced the shortcoming relevant with technology, and these shortcomings may surpass calcium oxide and reduce the advantage that is realized.Phosphate concn in the common unprocessed bayer liquors extremely surpasses 400ppm from about 40ppm noticeable change in the total alkaline solution of height.
Have been found that the reduction degree of the calcium oxide concentration affects calcium oxide concentration in the unprocessed bayer liquors, concentration is high more remarkable more and/or rapid to the influence that reduces.
Have been found that the reduction degree of the temperature effect calcium oxide concentration of unprocessed bayer liquors, temperature is high more remarkable more and/or rapid to the influence that reduces.Yet as skilled in the art to understand, the temperature variation of bayer liquors is the high energy consumption process, and the economical disadvantages that temperature raises may surpass by the temperature that changes bayer liquors to optimize the economical advantage that method of the present invention is obtained.
The present invention is in the outstanding work down of typical bayer liquor filtration temperature (100-105 ℃), but also can use down at wide temperature range (70 ℃ and more than).Although lower temperature causes slower deliming speed, this can compensate by controlling other process variable (for example, calcium and phosphate concn, residence time in phosphatic rock dosage and granularity, the feed solution).
Have been found that the reduction degree of the particle size influences calcium oxide concentration of a certain amount of phosphatic rock, granularity is more little remarkable more and/or quick to the influence that reduces.Yet in forms more of the present invention, a certain amount of phosphatic rock contacts with unprocessed bayer liquors from solid-solution separating step upstream.The example of these forms of the present invention is discussed below.In these forms of the present invention, the lower limit that solid-solution separating step can given phosphatic rock desired particle size, separated very essential from solution at least basically in solid-solution separating step because this is a phosphatic rock.
The beneficial effect that particle diameter reduces is considered to depend at least significantly the surface-area of increase, and surface-area is big more, and is remarkable more and/or quick to the influence that reduces.Therefore, in the preferred form of the present invention, a certain amount of phosphatic rock comprises the phosphatic rock with high surface area/volume ratio.Increase the surface-area of a certain amount of phosphatic rock and do not reduce granularity, perhaps by at least disproportionately reducing granularity, to more remarkable and/or reduce calcium oxide concentration fast benefit is provided, and do not cause or do not cause latent defect in solid-solution separating subsequently with proportional degree.
Therefore, have been found that the method according to this invention removes the effectiveness of calcium oxide and be subjected to following the influence:
(i) prepare phosphatic rock with the excessive phosphoric acid salt of stoichiometry, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, excessive many more, big more effectiveness is provided;
The (ii) phosphate concn of unprocessed bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, phosphate concn is high more, and big more effectiveness is provided;
The (iii) calcium oxide concentration of bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, calcium oxide concentration is high more, and big more effectiveness is provided;
The (iv) dosage of the phosphatic rock that contacts with bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, dosage is high more, and big more effectiveness is provided;
(time that v) a certain amount of phosphatic rock contacts with unprocessed bayer liquors, with regard to the degree of removing calcium oxide, the time is long more, and big more effectiveness is provided;
(the vi) particle diameter and/or the surface-area of the phosphatic rock that contacts with unprocessed bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, particle diameter is more little and/or surface-area is big more, and big more effectiveness is provided;
(temperature that vii) a certain amount of phosphatic rock contacts with unprocessed bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, temperature is high more, and big more effectiveness is provided; With
(the viii) degree of aging (age) of a certain amount of phosphatic rock that contacts with unprocessed bayer liquors, with regard to the degree of removing calcium oxide or can be at a time between in realize removing with regard to time of calcium oxide of expected degree, provide bigger effectiveness with new sedimentary phosphatic rock and/or the new phosphatic rock that contacts with phosphate solution.
By the requirement of the others defined of Bayer process limit one or whole above-mentioned mention factor to optimized degree to be implemented in the exact level of removing calcium oxide in the specific Bayer process refining.Combination and/or optimization to one or more factors of particular case are considered to fall within the scope of the present invention.
Title is for having discussed the Several combination of phosphate concn, calcium oxide concentration, temperature, particle diameter, granule surface area, phosphatic rock preparation condition, phosphatic rock degree of aging and phosphatic rock dosage in the part of " embodiment " below.These combinations only provide in an exemplary fashion, and should not be considered to limit the scope of the invention.
Such as in the context of the explanation of background technology explanation, calcium oxide can exist with the by product of expectation technology (for example causticization) in bayer liquors, and/or can be added into the alumina stable when the separating residual solid (red mud) from unprocessed solution for example with the result that realizes expectation.Therefore, it will be appreciated by those skilled in the art that the calcium oxide that is introduced in the bayer liquors as the by product of expecting technology can provide such as other process benefit of stablizing aluminum oxide during separating residual solid (red mud) from unprocessed solution.
In a kind of form of the present invention, method comprises the steps:
The dissolving aluminous ore is to be provided at the red mud slurry in the phosphatic unprocessed solution in caustic solution; Then
In the suspension of this red mud in unprocessed solution, add a certain amount of calcium oxide and containing suspension in calcium oxide and the phosphatic unprocessed solution to produce red mud; Then
Separating red mud from unprocessed solution; With
Unprocessed solution is contacted with a certain amount of phosphatic rock.
Thereby cause the precipitation of further phosphatic rock and reduce the concentration of calcium oxide in the unprocessed solution.
Separating red mud can take place simultaneously with the step that unprocessed solution is contacted with phosphatic rock from unprocessed solution.
In a kind of form of the present invention, the step of separating red mud comprises the flow through step of strainer of the suspension of red mud in unprocessed solution from unprocessed solution, with the step that takes place before the step of the strainer of flowing through in the suspension in the unprocessed solution of red mud and this will this unprocessed solution to contact with a certain amount of phosphatic rock.
In the preferred form of the present invention, the step of separating red mud comprises the steps: from unprocessed solution
The slurry stream of red mud and unprocessed solution through one or more sand-settling devices, is produced second slurries of red mud and unprocessed solution, and these second slurries contain the red mud of lower ratio with respect to unprocessed solution;
Through one or more thickners, generation is the thickener underflow of red mud basically and is the thickner overflow of unprocessed solution basically with this second slurry stream; With
Make the thickner overflow strainer of flowing through.
In this form of the present invention, the step of a certain amount of calcium oxide being added in the suspension of red mud and unprocessed solution is to take place before the step of strainer that the thickner overflow is flowed through.
When adding calcium oxide for the purpose of stablizing aluminum oxide, can with the slurry stream of red mud and unprocessed solution through one or more sand-settling devices, produce and to take place after the step of second slurries of red mud and unprocessed solution to add a certain amount of calcium oxide in the suspension of red mud and unprocessed solution step, described second slurries contain the red mud that hangs down ratio.
In addition, when adding calcium oxide for the purpose of stablizing aluminum oxide, can with second slurry stream through one or more thickners, produce and to be the thickener underflow of red mud basically and to be that step in the suspension of red mud and unprocessed solution is added a certain amount of calcium oxide in generation after the thickner overflow step of unprocessed solution basically.
In a kind of form of the present invention, strainer is fixed-bed type strainer, for example sand-bed filter.It will be apparent for a person skilled in the art that the fixed-bed type strainer has utilized one to be the bed that the inert filtration medium is formed at least basically, it is supported by screen cloth, solution this screen cloth of will flowing through.Use sand-bed filter as an example, casting bed is supported by metallic sieve, along with being pumped into bed, bayer liquors goes up or enters (normally by rotating the hole in the water jet standpipe) in the bed, and the gap in the bed of flowing through under gravity, the red mud particle in the feed bayer liquors is blocked in the sand grain surface on this.
When strainer is the fixed-bed type strainer, unprocessed bayer liquors contacted with a certain amount of phosphatic rock and makes the flow through step of strainer of thickner overflow comprise the thickner overflow is combined the strainer of then this binding substances being flowed through with a certain amount of phosphatic rock.
The common cyclical operation of fixed-bed type strainer: final, abundant granular material is being to accumulate almost completely to have reduced the effectiveness of strainer on the inertia filtration medium basically.At this moment, upgrade strainer usually by backwashing.Time between strainer upgrades is commonly referred to as a filtration cycle.
As discussed above, a series of factor is depended in the reduction of calcium oxide concentration, comprises residence time.In the preferred form of the present invention, thereby control these factors realize the calcium oxide concentration of expectation in being less than or equal to the residence time of single filtration cycle reduction.In this case, suppose constant feed condition, at any given time the decline of the calcium oxide that takes place by the circulation of each strainer should with give proportional until this time point to strainer with the total mass of phosphatic rock.
In a kind of form of the present invention, strainer is a cake formula strainer.It will be apparent for a person skilled in the art that; cake formula strainer is such strainer; it is pumped in the strainer flocculating aids solid (thin but that be easy to be filtered, chemically inert granulating solid) with strainer filter cake precoat filter liquid plate (sieve structure that is covered by grid cloth strainer cloth); it allows solution stream through its pore structure when pumping into unprocessed solution by strainer; but hold back the mud solid, selectively under gravity or the vacuum but usually (filter) under pressure (as at the Kelly strainer) and carry out for unprocessed bayer liquor.
The flocculating aids solid can be pumped to strainer in following any one or two kinds of modes:
(i) before main filtration stream, on the strainer impeller, to form initial no mud strainer cake layer; And/or
(ii) be mixed in the strainer feed solution, produce the strainer cake layer of holding back mud to run through each unprocessed bayer liquor filtration cycle by easy stages.
In a kind of form of the present invention, when strainer is cake formula strainer, unprocessed solution is comprised step with the step that contacts of a certain amount of phosphatic rock:
Add a certain amount of phosphatic rock to the thickner overflow.
In a kind of form of the present invention, when strainer was cake formula strainer, the step of separating red mud comprised the steps: from unprocessed solution
The thickner overflow is mixed with a certain amount of flocculating aids; With
With the thickner overflow strainer of flowing through.
When the present invention includes thickner overflow and a certain amount of flocculating aids blended step, this method can be included in the additional step before this step:
A certain amount of phosphatic rock is mixed with a certain amount of flocculating aids;
So that thickner overflow and a certain amount of flocculating aids blended step are influenced the step that unprocessed solution is contacted with a certain amount of phosphatic rock.
In a kind of form of the present invention, when strainer was cake formula strainer, the step of separating red mud comprised the steps: from unprocessed solution
To cake formula filter application flocculating aids layer; Then
With thickner overflow flow through flocculating aids layer and strainer.
When the step that the present invention includes to filter application flocculating aids layer, this method can be included in the additional step before this step:
A certain amount of phosphatic rock is mixed with a certain amount of flocculating aids;
So that with the thickner overflow step influence of flocculating aids layer and strainer contacts unprocessed solution with a certain amount of phosphatic rock the step of flowing through.
In a kind of form of the present invention, when strainer is cake formula strainer, the step of red mud from unprocessed solution separating comprised the steps:
The slurry stream of red mud and unprocessed solution through one or more sand-settling devices, is produced second slurries of red mud and unprocessed solution, and these second slurries contain the red mud of lower ratio with respect to unprocessed solution;
Through one or more thickners, generation is the thickener underflow of red mud basically and is the thickner overflow of unprocessed solution basically with this second slurry stream;
The phosphatic rock of first amount is mixed to produce first mixture with the flocculating aids of first amount;
First mixture layer is applied to strainer;
With the flocculating aids of second amount and mixing of second phosphatic rock of measuring to produce second mixture;
Second mixture is mixed with the thickner overflow; Then
With thickner overflow flow through first mixture layer and strainer;
So that second mixture and thickner overflow mixed and flow through per step of step of first mixture layer and strainer of thickner overflow all influenced the step that unprocessed solution is contacted with a certain amount of phosphatic rock.
Preferably, the granularity of phosphatic rock and flocculating aids is similar.That is to say the thinless risk of polluting to the remarkable phosphatic rock that causes filtrate and not have slightly to remove the required surface-area of calcium oxide of enough ratios to losing.The phosphatic rock that mainly drops on 5-15 micron granularity scope will satisfy this two standards.Perhaps, and as discussed above, can use the bigger particle diameter of surface-area with increase.
Usually can be at many Bayer process refinery situ production phosphatic rock, this gives and the invention provides extra advantage.
For example, can prepare phosphatic rock by interpolation lime source and phosphate source in bayer liquors.In a kind of form of the present invention, the lime source provides with the form of white lime, tricalcium aluminate or filter pressing sludge.Phosphate source and bayer liquors can high phosphate Bayer process waste liquid form provide together.In about 90 ℃ temperature, the residence time that is used to prepare phosphatic rock is very short, about 15-30min.So the phosphatic rock of producing can be separated from residual solution before being used for method of the present invention.Perhaps, the slurries of phosphatic rock and upper solution can be used for method of the present invention.
International patent application (PCT/AU2006/000140) (Alcoa of Australia Limited) thus described in bayer liquors by adding phosphate source causticization phosphoric acid salt and controlled the precipitation that this phosphoric acid salt impels the calcium phosphate precipitation thing, in a kind of form of the present invention, this throw out is a phosphatic rock.The cost of phosphate source is obviously depended in the practical application of these methods.Therefore method of the present invention promotes causticization phosphoric acid salt and this phosphatic method of control in the bayer liquors of (PCT/AU2006/000140) slightly by using so elementary by product.
Therefore, according to the present invention, provide a kind of method that is used to handle bayer liquors, this method comprises the steps:
In bayer liquors, add phosphate source;
In this bayer liquors, add caustic alkali reagent; With
Form with a certain amount of phosphatic rock forms the calcium phosphate precipitation thing;
Thereby make this bayer liquors causticization; Then
This bayer liquors is contacted with at least a portion of a certain amount of phosphatic rock; With
Thereby cause that further phosphatic rock precipitates and reduce the calcium oxide concentration of this bayer liquors.
As used herein, term " phosphate source " will be used to include but not limited to provide any form of the anionic phosphorus of orthophosphoric acid salt in bayer liquors.
Valuably, method of the present invention allows the bayer liquors causticization and controls phosphoric acid salt and calcium concn in this solution simultaneously.
Description of drawings
Below with reference to two kinds of embodiments and accompanying drawing, only describe and carry out optimal mode of the present invention in the mode of example, wherein:
Fig. 1 is schematically illustrating of Bayer process, wherein uses cake formula strainer separating residual solid (red mud) from unprocessed bayer liquor, and it shows first embodiment of the present invention;
Fig. 2 is schematically illustrating of Bayer process, wherein uses cake formula strainer separating residual solid (red mud) from unprocessed bayer liquor, and it shows second embodiment of the present invention;
Fig. 3 illustrates the chart of the residence time of hydroxylapatite carbonate to the influence of calcium oxide concentration;
Fig. 4 illustrates hydroxylapatite carbonate and the flocculating aids concentration chart to the influence of calcium oxide concentration;
Fig. 5 is illustrated in the continuous cake formula filtration process hydroxylapatite carbonate to the graphic representation of the influence of calcium oxide concentration; With
Fig. 6 illustrates hydroxylapatite carbonate and the flocculating aids graphic representation to the influence of calcium oxide concentration;
Fig. 7 shows from a series of result of experiment, wherein prepares hydroxylapatite carbonate in containing the excessive phosphatic solution of stoichiometry;
Fig. 8 shows that from a series of result of experiment its explanation phosphatic rock wears out to the influence of the effectiveness of removing calcium oxide; With
Fig. 9 has compared the fresh phosphatic rock of recovery and the amount of 1 day age and freshly prepd phosphatic rock calcium oxide of removing from solution used.
Yet, this description should be interpreted as the present invention's general introduction that limits the front by any way.
Embodiment
With reference to figure 1, the reduction of use first embodiment contains the method for the calcium oxide concentration in calcium oxide and the phosphatic unprocessed bayer liquors in Bayer process, wherein, salic ore is dissolved in the caustic solution 10, the slurries 12 of red mud in phosphatic unprocessed solution are provided.Make the slurry stream of this red mud in phosphatic unprocessed solution through thickner 14 then, generation is the thickener underflow 16 of red mud basically and is the thickner overflow 18 of unprocessed bayer liquor basically.
Except phosphoric acid salt, thickner overflow 18 also contains calcium oxide.This calcium oxide can be derived from many possible sources any or multiple.For example, by add from the high-enriched organics solution, as the lime or the calcite (for example during the technology of solution causticization) of the by product of other Bayer process, and/or by the interpolation calcium oxide of having a mind to so that stablize aluminum oxide.
Use the method for first embodiment in Bayer process, it utilizes cake formula strainer 20.A certain amount of Ca
7Na
2(CO
3)
3(PO
4)
3(H
2O)
3(OH) the phosphatic rock carbonate 22 of form combines to form precoating 26 with the flocculating aids 24 of first amount and is applied to cake formula strainer 20 as layer then.The flocculating aids 28 of second amount mixes with thickener underflow 18 to form the slurries 30 of flocculating aids and thickner overflow.
The amount that is applied to the phosphatic rock carbonate 22 of cake formula strainer 20 depends on a series of factor, wherein considerable is the reduction (with the speed that reduces) of the calcium oxide concentration of expectation, such as in the general introduction of the present invention in front discussion, measure big more cause reduction many more/fast more.In addition, and also discuss in front the general introduction of the present invention, the characteristic of phosphatic rock carbonate 22 (for example particle diameter and surface-area) influence realizes that in preset time given calcium oxide concentration reduces required amount.In addition, and also discuss in front the general introduction of the present invention, the characteristic of thickener underflow 18 (for example calcium oxide concentration, phosphate concn and temperature) influence realizes that in preset time given calcium oxide concentration reduces required amount.
Can change the influence that these parameters produce the method for this embodiment with the factor of other relevant Bayer process with balance.There is not a cover optimum parameter.Yet common expectation is chosen in the interior parameter combination that realizes the calcium oxide minimizing of expectation of setting-up time of a filtration cycle.
Although a certain amount of phosphatic rock carbonate 22 can be derived from any source, easily, this a certain amount of phosphatic rock carbonate 22 is as the by product of another Bayer process step and produce.
The cake formula strainer 20 of then slurries 30 being flowed through contacts thereby make the unprocessed bayer liquor that exists with thickner overflow 18 forms in the slurries 30 and be applied to a certain amount of phosphatic rock carbonate 22 that exists in the layer of cake formula strainer 20.This causes the calcium oxide concentration in further phosphatic rock precipitation and the reduction bayer liquors.
With reference now to Fig. 2,, with the substantially similar Bayer process of the Bayer process of the method for using first embodiment in use the method that the calcium oxide concentration that contains calcium oxide and phosphatic unprocessed bayer liquors of second embodiment reduces, and will use the identical parts of identical numeral.Yet the Bayer process of using the method for second embodiment uses fixed bed filtering device 32 to replace cake formula strainer.
Depend on a series of factor with the amount of thickner overflow 18 blended phosphatic rock lime carbonate 34, wherein considerable is the reduction (with the speed that reduces) of the calcium oxide concentration of expectation, such as in the general introduction of the present invention in front discussion, measure the big more many more/fast more reduction that causes.In addition, and also discuss in front the general introduction of the present invention, the characteristic of phosphatic rock carbonate 34 (for example particle diameter and surface-area) influence realizes that in preset time given calcium oxide concentration reduces required amount.In addition, and also discuss in front the general introduction of the present invention, the characteristic of thickener underflow 18 (for example calcium oxide concentration, phosphate concn and temperature) influence realizes that in preset time given calcium oxide concentration reduces required amount.
Can change the influence that these parameters produce the method for this embodiment with the factor of other relevant Bayer process with balance.There is not a cover optimum parameter.
Result and embodiment
Table 1 and Fig. 3 show with hydroxylapatite carbonate-Ca
7Na
2(CO
3)
3(PO
4)
3(H
2O)
3(OH)-and a series of result of experiment of carrying out, illustrate that phosphatic rock is in the effectiveness of removing the dissolved calcium oxide from bayer liquors.
To contain 80,160 and 250ppm phosphoric acid salt (be expressed as P
2O
5) unprocessed solution to be heated to temperature be 95 ℃.Dosage with 0.2g phosphatic rock/L or 1g phosphatic rock/L adds hydroxylapatite carbonate in solution.This mixture is mixed 1min or 10min under this temperature.
The data presentation that table 1 provides and hydroxylapatite carbonate contact the concentration that reduces calcium oxide in the solution.The reduction degree of calcium oxide concentration depends on phosphatic concentration in dosage, retention time and the solution in the solution.
Table 1
| ppm P 2O 5 | Be in 95 ℃ time | Phosphatic rock dosage (g/L) | CaO descend (mg/L) |
| 80 | |
1 | 16.1 |
| 160 | |
1 | 17.2 |
| 250 | |
1 | 20.4 |
| 80 | |
1 | 21.3 |
| 160 | |
1 | 21.5 |
| 250 | |
1 | 21.8 |
| 80 | 10min | 0.2 | 11.1 |
| 160 | 10min | 0.2 | 16.4 |
| 250 | 10min | 0.2 | 16.6 |
Table 2 and Fig. 4 have shown a series of result of experiment, and wherein hydroxylapatite carbonate mixes with tricalcium aluminate (TCA) with proof in the presence of flocculating aids, and phosphatic rock is removed the effectiveness of dissolved calcium oxide from bayer liquors.
Pure unprocessed solution and the unprocessed solution that contains 0.5g TCA/L is heated to 95 ℃ temperature.Dosage with 0.2g phosphatic rock/L or 1g phosphatic rock/L adds hydroxylapatite carbonate in solution.This mixture is mixed 1min or 10min under this temperature.
The data presentation that table 2 provides has reduced the concentration of calcium oxide in the solution with contacting of hydroxylapatite carbonate in the presence of flocculating aids.The reduction degree of calcium oxide concentration still depends on dosage and retention time in the solution.
Table 2
| Be in 95 ℃ time | Phosphatic rock dosage (g/L) | TCA dosage (g/L) | CaO descend (mg/L) |
| 0 | 0 | 0 | 13.1 |
| 1min | 0.2 | 0 | 20.2 |
| |
1 | 0 | 16.9 |
| 10min | 0.2 | 0 | 23.8 |
| |
1 | 0 | 11.9 |
| 1min | 0.2 | 0.5 | 20.6 |
| |
1 | 0.5 | 17.5 |
| 10min | 0.2 | 0.5 | 24.8 |
| |
1 | 0.5 | 13.1 |
Embodiment 3
Table 3 and Fig. 5 have shown the lab scale result of experiment, and wherein hydroxylapatite carbonate mixes the effectiveness of removing the dissolved calcium oxide from bayer liquors with proof phosphatic rock in cake formula filtration process continuously with tricalcium aluminate (TCA) as flocculating aids.
The dosage of 500g hydroxylapatite carbonate with 0.04g phosphatic rock/g TGA is joined in the tricalcium aluminate slurries.The flocculating aids slurries are joined in the unprocessed solution and surpass about 6h the time chien shih mixture flow through the Kelly strainer.
The data presentation that table 3 provides when hydroxylapatite carbonate in the strainer filter cake with after flocculating aids mixes, it has reduced the concentration of the calcium oxide in the solution.The reduction degree of calcium oxide concentration is along with the increase of the thickness of cake and the therefore increase of the amount of hydroxylapatite carbonate and improving in the strainer filter cake.
Table 3
| Line duration (h:mm) | CaO descend (mg/L) |
| 0:00 | 5.1 |
| 0:15 | 4.0 |
| 0:45 | 4.5 |
| 1:15 | 5.9 |
| 2:15 | 7.0 |
| 2:45 | 7.1 |
| 3:15 | 8.3 |
| 3:45 | 9.1 |
| 4:15 | 9.0 |
| 4:45 | 8.8 |
| 5:15 | 10.3 |
| 5:45 | 11.5 |
Table 4 and Fig. 6 have shown the lab scale result of experiment, and wherein hydroxylapatite carbonate mixes with tricalcium aluminate (TCA) and is applied to filter media as pre-filtering coating (precoated layer).
The dosage of 500g hydroxylapatite carbonate with 0.27g phosphatic rock/g TGA is joined in the tricalcium aluminate slurries.Before solution filters, this mixture is applied to the cloth film of kelly strainer as coating.To there be the other flocculating aids slurries of hydroxylapatite carbonate to add unprocessed solution.Surpass 5h the time chien shih mixture flow through Kelly strainer and phosphatic rock/TCA coating.
The data presentation that table 4 provides is after hydroxylapatite carbonate mixes with flocculating aids and uses as precoated layer, and it has reduced the concentration of the calcium oxide in the solution.When the semi-invariant of phosphatic rock in the strainer filter cake equaled amount in the precoated layer at current embodiment, the reduction degree of calcium oxide concentration was comparable to the last degree that realizes of experiment of embodiment 3 always in the whole experiment.
Table 4
| Line duration (h:mm) | CaO descend (mg/L) |
| 2:30 | 12.0 |
| 3:00 | 13.6 |
| 3:30 | 13.6 |
| 4:00 | 13.8 |
| 4:30 | 14.4 |
| 5:00 | 14.7 |
Embodiment 5: preparation excessive phosphoric acid salt during phosphatic rock
Fig. 7 has shown a series of result of experiment, and wherein preparation hydroxylapatite carbonate is being removed aspect the calcium oxide improving the active influence of phosphatic rock with proof excess phosphoric acid salt in containing the excessive phosphate solution of stoichiometry.
With Na
3PO
412H
2O is dissolved in the part of pure waste liquid and this solution is heated to 90 ℃ temperature.White lime is added in the solution, with stoichiometry or molar ratio computing, so that the phosphate concn in the solution is a stoichiometry excessive 50% or 100% with respect to stoichiometric hydroxylapatite carbonate.Mixture was reacted 15 minutes under this temperature, utilize then to filter the phosphatic rock sample is separated from solution with washing.
To contain the 50ppm phosphoric acid salt of having an appointment and (be expressed as P
2O
5) pure unprocessed solution be heated to 95 ℃ temperature.The hydroxylapatite carbonate of preparation is joined in the solution with the dosage of about 1g phosphatic rock/L.Make mixture under this temperature, mix 10min.
The effectiveness that digital proof shown in Fig. 7 uses the hydroxylapatite carbonate that contains in the phosphatic solution of lower concentration to remove calcium oxide can improve by preparation hydroxylapatite carbonate in the solution that contains excess phosphoric acid salt.This effect is proportional with the percentage ratio for preparing excess phosphoric acid salt in the solution.
Embodiment 6: aged phosphatic rock and new phosphatic rock
Fig. 8 has shown a series of result of experiment, and it has proved the aging influence to the effectiveness of removing calcium oxide of phosphatic rock.
Ortho-phosphoric acid is joined pure waste liquid and this solution is heated to 90 ℃ temperature.Stoichiometry with respect to the metering of hydroxylapatite carbonate chemistry joins solution with white lime.Mixture was reacted 15 minutes under this temperature, utilize then to filter the phosphatic rock sample is separated from solution with washing.Near the wet cake of half in room temperature storage 24h.
To contain the 40-60ppm phosphoric acid salt of having an appointment and (be expressed as P
2O
5) pure unprocessed solution be heated to 95 ℃ temperature.With freshly prepd hydroxylapatite carbonate sample with about 0.2,0.3 and the dosage of 1g phosphatic rock/L add solution.Make mixture under this temperature, react 10min.Use the wet phosphatic rock that stores behind 24h, to repeat this experiment.
It is proportional that the data presentation of Fig. 8 uses new phosphatic rock to remove the dosage of calcium oxide and used phosphatic rock, or even in containing the phosphatic solution of lower concentration.On the contrary, no matter what dosage phosphatic rock is, the concentration of the calcium oxide of being removed from solution by " aged " phosphatic rock can be ignored, and proves that phosphatic rock loses its " activity " between the shelf lives.
Embodiment 7: the phosphatic rock of reactivate
Fig. 9 shows a series of result of experiment, and its proof aged phosphatic rock is removed the ability of calcium oxide and can be regenerated by soak phosphatic rock in the solution that contains excess phosphoric acid salt.
With Na
3PO
412H
2O is dissolved in the part of pure waste liquid and solution is heated to 90 ℃ temperature.Hydroxylapatite carbonate is joined in the solution with such molar ratio, so that the phosphate concn in solution is that 100% stoichiometry is excessive with respect to the stoichiometry of hydroxylapatite carbonate.Mixture was reacted 15 minutes under this temperature, utilize then to filter the phosphatic rock sample is separated from solution with washing.
To contain 40-50ppm phosphoric acid salt and (be expressed as P
2O
5) pure unprocessed solution be heated to 95 ℃ temperature." recovering fresh " hydroxylapatite carbonate sample is joined solution with the dosage of about 1g phosphatic rock/L.Make mixture under this temperature, mix 10min.
The amount that Fig. 9 has compared that use " recovers fresh " phosphatic rock and 1 day age and freshly prepd phosphatic rock are removed calcium oxide from solution.Data shown in Fig. 9 show that the activity of aged phosphatic rock can be regenerated by soak hydroxylapatite carbonate in the solution that contains excess phosphoric acid salt for removing calcium oxide.
Embodiment 1-7 clearly proves the effectiveness of the calcium oxide concentration of method of the present invention in reducing bayer liquors.
Conspicuous for those skilled in the art change and variation are considered to fall within the scope of the present invention.
Claims (25)
1, a kind of reduction contains the method for calcium oxide concentration in calcium oxide and the phosphatic unprocessed bayer liquors, and described method comprises the steps:
Unprocessed bayer liquors is contacted with a certain amount of phosphatic rock;
Thereby cause further phosphatic rock precipitation and reduce calcium oxide concentration in the unprocessed bayer liquors.
2, method according to claim 1 is characterized in that, described calcium oxide and the phosphatic unprocessed bayer liquors of containing is by following step production:
The salic ore of dissolving is to provide the slurries of red mud in phosphatic unprocessed solution in caustic solution; Then
In the suspension of described red mud in unprocessed solution, add a certain amount of calcium oxide and containing suspension in calcium oxide and the phosphatic unprocessed solution to produce red mud; Then
Separating red mud contains calcium oxide and phosphatic unprocessed bayer liquors with production from unprocessed solution.
3, method according to claim 2 is characterized in that, described from unprocessed solution separating red mud with will contain calcium oxide and can take place simultaneously with the step that phosphatic unprocessed bayer liquors contacts with phosphatic rock.
4, according to claim 2 or 3 described methods, it is characterized in that, described from unprocessed solution the step of separating red mud comprise the flow through step of strainer of the suspension of red mud in described unprocessed solution, flow through with the suspension of red mud in described unprocessed solution and the described step that unprocessed solution is contacted with a certain amount of phosphatic rock take place at once before the step of strainer.
5, according to each described method among the claim 2-4, it is characterized in that, described from unprocessed solution the step of separating red mud comprise the steps:
The slurry stream of red mud and unprocessed solution through one or more sand-settling devices, is produced second slurries of red mud and unprocessed solution, and described second slurries contain the red mud with respect to the lower ratio of unprocessed solution;
Through one or more thickners, generation is the thickener underflow of red mud basically and is the thickner overflow of unprocessed solution basically with described second slurry stream; With
Make the thickner overflow strainer of flowing through;
Wherein said step of adding a certain amount of calcium oxide in the suspension of red mud in unprocessed solution flows through the thickner overflow to take place before the step of strainer described.
6, according to each described method among the claim 2-5, it is characterized in that, add described calcium oxide for the purpose of stablizing aluminum oxide, and adding a certain amount of calcium oxide in the suspension of red mud in unprocessed solution step is to occur in after described slurry stream with red mud and unprocessed solution produces red mud and unprocessed solution through one or more sand-settling devices the step of second slurries, and described second slurries contain the red mud of low ratio.
7, according to each described method among the claim 2-6, it is characterized in that, add described calcium oxide for the purpose of stablizing aluminum oxide, and to add a certain amount of calcium oxide in the suspension of red mud in unprocessed solution step be to occur in described second slurry stream produced through one or more thickners to be the thickener underflow of red mud basically and to be after the step of thickner overflow of unprocessed solution basically.
8, according to each described method among the claim 4-7, it is characterized in that, described strainer is the fixed-bed type strainer, and describedly unprocessed bayer liquors is contacted with a certain amount of phosphatic rock and make the flow through step of strainer of thickner overflow comprise and described thickner overflow is combined the strainer of then described binding substances being flowed through with a certain amount of phosphatic rock.
According to each described method among the claim 4-7, it is characterized in that 9, described strainer is a cake formula strainer.
10, method according to claim 9 is characterized in that, described unprocessed solution is comprised step with the step that a certain amount of phosphatic rock contacts:
In the thickner overflow, add a certain amount of phosphatic rock.
11, according to claim 9 or 10 described methods, it is characterized in that, described from unprocessed solution the step of separating red mud comprise the steps:
The thickner overflow is mixed with a certain amount of flocculating aids; With
With the described thickner overflow strainer of flowing through.
12, method according to claim 11 is characterized in that, before with thickner overflow and a certain amount of flocculating aids blended step, described method comprises step:
A certain amount of phosphatic rock is mixed with a certain amount of flocculating aids;
So that thickner overflow and a certain amount of flocculating aids blended step are influenced the step that unprocessed solution is contacted with a certain amount of phosphatic rock.
13, according to each described method among the claim 9-12, it is characterized in that the step of separating red mud comprises the steps: from unprocessed solution
A certain amount of phosphatic rock is mixed with a certain amount of flocculating aids;
To cake formula filter application flocculating aids layer; Then
With thickner overflow flow through flocculating aids layer and strainer;
So that with the thickner overflow step influence of flocculating aids layer and strainer contacts unprocessed solution with a certain amount of phosphatic rock the step of flowing through.
14, method according to claim 2 is characterized in that, described from unprocessed solution the step of separating red mud comprise the steps:
The slurry stream of red mud and unprocessed solution through one or more sand-settling devices, is produced second slurries of red mud and unprocessed solution, and described second slurries contain the red mud with respect to the lower ratio of unprocessed solution;
Through one or more thickners, generation is the thickener underflow of red mud basically and is the thickner overflow of unprocessed solution basically with described second slurry stream;
The phosphatic rock of first amount is mixed to produce first mixture with the flocculating aids of first amount;
First mixture layer is applied to cake formula strainer;
With the flocculating aids of second amount and mixing of second phosphatic rock of measuring to produce second mixture;
Second mixture is mixed with the thickner overflow; Then
With thickner overflow flow through first mixture layer and cake formula strainer;
So that second mixture and thickner overflow mixed and flow through per step of step of first mixture layer and strainer of thickner overflow all influenced the described step that unprocessed solution is contacted with a certain amount of phosphatic rock.
15, a kind of method of handling bayer liquors, described method comprises the steps:
In bayer liquors, add phosphate source;
In described this bayer liquors, add caustic alkali reagent; With
Form with a certain amount of phosphatic rock forms the calcium phosphate precipitation thing;
Thereby make described bayer liquors causticization; Then
Described bayer liquors is contacted with at least a portion of a certain amount of phosphatic rock; With
Thereby cause that further phosphatic rock precipitates and reduce the calcium oxide concentration of described bayer liquors.
16, according to the described method of aforementioned arbitrary claim, it is characterized in that described phosphatic rock has general formula A
10(XO
4)
6(OH, F, Cl)
2NH
2O, wherein: A can be selected from Ba, Ca, Ce, K, Na, Pb, Sr, Y; X can be selected from As, P, Si, V and PO
4Can be by CO
3Replace.
17, method according to claim 16 is characterized in that, described A is that Ca and Na and described phosphatic rock are at least mainly to have general formula Ca
10-xNa
2x/3(PO
4)
6-x(CO
4)
x(OH)
2-x/3XH
2O, wherein, the hydroxylapatite carbonate of 0≤x≤3, or be provided with any mixture of this compound.
18, method according to claim 16 is characterized in that, described phosphatic rock is with Ca
7Na
2(CO
3)
3(PO
4)
3(H
2O)
3(OH) form is provided.
According to the described method of aforementioned arbitrary claim, it is characterized in that 19, described phosphatic rock is by the excessive phosphoric acid salt preparation of stoichiometry.
According to the described method of aforementioned arbitrary claim, it is characterized in that 20, described phosphatic rock is newly sedimentary.
According to the described method of aforementioned arbitrary claim, it is characterized in that 21, the amount of described phosphatic rock is 20-25g in every kL bayer liquors.
22, according to the described method of aforementioned arbitrary claim, it is characterized in that, the phosphatic concentration of described bayer liquors be between about 50 and 400ppm between.
According to the described method of aforementioned arbitrary claim, it is characterized in that 23, the temperature in the described bayer liquors is between about 70 ℃ and 120 ℃.
24, method according to claim 23 is characterized in that, the temperature in the described bayer liquors is between about 100 ℃ and 105 ℃.
According to the described method of aforementioned arbitrary claim, it is characterized in that 25, described a certain amount of phosphatic rock comprises the phosphatic rock with high surface area/volume ratio example.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2006901815A AU2006901815A0 (en) | 2006-04-07 | Method of Reducing Calcia Concentrations of Green Bayer Process Liquors | |
| AU2006901815 | 2006-04-07 | ||
| PCT/AU2007/000460 WO2007115365A1 (en) | 2006-04-07 | 2007-04-05 | Method of reducing calcia concentrations of green bayer process liquors |
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|---|---|
| CN101437758A true CN101437758A (en) | 2009-05-20 |
| CN101437758B CN101437758B (en) | 2013-04-24 |
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| CN200780016077.6A Active CN101437758B (en) | 2006-04-07 | 2007-04-05 | Method of reducing calcia concentrations of green bayer process liquors |
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| Country | Link |
|---|---|
| CN (1) | CN101437758B (en) |
| AU (1) | AU2007236547B2 (en) |
| BR (1) | BRPI0709478A2 (en) |
| RU (1) | RU2445264C2 (en) |
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Cited By (1)
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|---|---|---|---|---|
| CN103717533A (en) * | 2011-08-08 | 2014-04-09 | 巴斯夫欧洲公司 | Method for producing ultrapure aluminum oxide by cleaning clay |
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| CN101264910B (en) * | 2008-04-25 | 2010-10-13 | 河南未来铝业（集团）有限公司 | Mother liquor evaporation seed addition method for aluminum hydroxide or aluminum oxide production technique by Bayer process |
| FR2934852B1 (en) * | 2008-08-06 | 2011-06-24 | Alcan Int Ltd | IMPROVEMENT TO THE BAYER PROCESS FOR PRODUCTION OF ALUMINA TRIHYDRATE, SAID PROCESS COMPRISING A STEP IN WHICH THE SURSATURATED LIQUEUR IS FILTERED AT HIGH TEMPERATURE BEFORE DECOMPOSITION |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4016238A (en) * | 1975-08-29 | 1977-04-05 | Urbina Davalos Fernando | Process for the obtention of alumina and phosphate values by the alkaline decomposition of silica-containing aluminum phosphate ores |
| SU814866A1 (en) * | 1979-05-07 | 1981-03-23 | Всесоюзный Научно-Исследовательскийи Проектный Институт Алюминиевой,Магниевой И Электродной Промышленности | Method of processing sulfide-sulfate mixture |
| HU187654B (en) * | 1982-02-26 | 1986-02-28 | Ajkai Timfoeldgyar Aluminium | Process for reduction of damages in production of aluminium oxid of bayer system |
| JPS59156489A (en) * | 1983-02-28 | 1984-09-05 | Kurita Water Ind Ltd | Phosphate-contg. water disposal |
| FR2589850B1 (en) * | 1985-11-08 | 1990-08-31 | Rhone Poulenc Spec Chim | IMPROVEMENT IN A PROCESS FOR THE PRODUCTION OF RARE EARTH HYDROXIDES BY THE TREATMENT OF ORES CONTAINING RARE EARTH PHOSPHATES |
| US5534235A (en) * | 1995-09-05 | 1996-07-09 | Nalco Chemical Company | Polymers containing phosphonic acid groups for the treatment of red mud in the Bayer process |
| RU2188794C1 (en) * | 2001-03-28 | 2002-09-10 | Государственное унитарное предприятие Уральский научно-исследовательский химический институт с опытным заводом | Method of processing soda-sulfate mixture |
| CN1297480C (en) * | 2002-03-05 | 2007-01-31 | 平顶山市汇源化学工业公司 | Process for removing organics from sodium Bayer process aluminate solution |
| EP1858808A1 (en) * | 2005-02-03 | 2007-11-28 | Alcoa Of Australia Limited | Method for the causticisation of bayer process solutions |
-
2007
- 2007-04-05 BR BRPI0709478-7A patent/BRPI0709478A2/en not_active Application Discontinuation
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Cited By (1)
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|---|---|---|---|---|
| CN103717533A (en) * | 2011-08-08 | 2014-04-09 | 巴斯夫欧洲公司 | Method for producing ultrapure aluminum oxide by cleaning clay |
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| BRPI0709478A2 (en) | 2011-07-19 |
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| RU2008143330A (en) | 2010-05-20 |
| CN101437758B (en) | 2013-04-24 |
| AU2007236547B2 (en) | 2012-05-03 |
| WO2007115365A1 (en) | 2007-10-18 |
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