CN101734694A - Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method - Google Patents
Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method Download PDFInfo
- Publication number
- CN101734694A CN101734694A CN200810305581A CN200810305581A CN101734694A CN 101734694 A CN101734694 A CN 101734694A CN 200810305581 A CN200810305581 A CN 200810305581A CN 200810305581 A CN200810305581 A CN 200810305581A CN 101734694 A CN101734694 A CN 101734694A
- Authority
- CN
- China
- Prior art keywords
- hyperconcentration
- sodium oxalate
- alumina
- lime
- mother liquor
- 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.)
- Granted
Links
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention discloses a method for excluding sodium oxalate and carbonate from Bayer process solution by adopting an ultra-concentration method. The method comprises the steps of: concentrating the mother liquor of an alumina system, sending liquor in the concentrated mother liquor to an alumina production system, and then send to a first segment causticization tank for causticizing for 2 to 4 hours to obtain seriflux B after solid phase dissolution; cooling the seriflux B to 50 to 70 DEG C and send to a second segment causticization tank for causticizing for 1.5 to 3 hours at 50 to 70 DEG C to obtain seriflux C; sending the seriflux C into a separating and washing machine, sending washed liquid to the alumina production system, and sending residues an alumina red mud washing system. The invention not only has the advantages of good excluding effect, simple process, less investment and low production and operation cost, but also achieves less loss of alumina, and has good use value and economic value.
Description
Technical field:
The present invention relates to a kind of method that adopts the hyperconcentration method from Bayer process solution, to get rid of sodium oxalate and carbonate, belong to the technical field of getting rid of Bayer process solution medium-height grass hydrochlorate and carbonate.
Technical background:
The source of alumina producing flow process mesoxalic acid sodium is mainly carrying of bauxite, secondly is to contain organic subsidiary material (as: flocculation agent, lubricant, antifoams etc.) for what satisfy to produce that needs add.Because of sodium oxalate constantly accumulation on stream, after reaching certain concentration, accumulation will bring great harm to alumina producing, its main harm is: 1, reduce quality product: the solubleness of sodium oxalate in sodium aluminate solution is along with the reduction of temperature reduces, decomposition in the bayer's process production is a temperature-fall period, this just separates out for the sodium oxalate crystalline and has created convenience, thereby has a strong impact on quality product.2, sodium oxalate impels the generation of fine particle aluminum hydroxide crystals, thereby cause product granularity defective, separate out simultaneously with aluminium hydroxide at decomposition course mesoxalic acid sodium, therefore will cause the further refinement of product granularity at the hydroxide roasting process, sodium oxalate and aluminium hydroxide are separated out jointly, can cause the content of aluminum hydroxide crystals alkali to increase.3, reduced the speed of agglomeration efficient and crystal growth in the decomposition course, made and decompose that output capacity reduces and the cycle efficiency reduction.4, contain the higher solution of sodium oxalate and can produce a large amount of foams, cause equipment can not satisfy load operation at conveying and storage process.5, sodium oxalate reaches capacity after the concentration, will be at the seed vertical-disk filter, separate out the positions such as hot face of the heat-transfer surface of seminal fluid heat exchange, decomposer inner peripheral wall and vaporizer, and this not only causes the production capacity of equipment own to reduce, and can cause the equipment cleaning cycle to shorten, operation rate is low; Can cause the heat-transfer effect of vaporizer, heat exchanging apparatus to reduce in addition.6, a large amount of normal pressure equipment is arranged in the alumina producing, alkali lye or slip overflow together in company with the organism foam in careless slightly this this equipment, influence industrial hygiene and environment protection.
The method for removing of existing sodium oxalate mainly contains: 1, roasting method: bauxite is carried out preroasting, or the fine particle aluminium hydroxide of aluminum oxide production process carried out roasting, though this method can effectively be got rid of sodium oxalate, but its construction investment height, energy consumption height and contaminate environment.2, aluminum hydroxide wash liquor causticizing process: need carry out twice classification and the once sedimentation of thin aluminium hydroxide in order to obtain thin crystal seed, then settled underflow is separated and washing, its washing lotion is carried out causticization under the condition that adds excessive lime, realize the eliminating of sodium oxalate.This method first pass complexity: not only the Operation and Maintenance workload is big, the construction investment height, and only should be used for two sections decomposition, limited because of the amount of the thin aluminium hydroxide of aluminum oxide factory, the amount of washing lotion mesoxalic acid sodium is just more limited, so the eliminating amount of sodium oxalate is few; The second, because of having increased the washing procedure of thin aluminium hydroxide,, further increased the difficulty of alumina producing water, and can increase heat energy consumption so need increase water consumption; Three, the washing lotion causticization need add excessive lime, causes aluminum oxide and lime complete reaction generation calcium aluminate solid phase in the washing lotion therefrom, and alumina loss is bigger.3, oxidation style: be in the alumina producing flow process, to select suitable place to add oxygenant, make the sodium oxalate in the Bayer process solution be converted into carbonate.Though this method has the organic effect of tangible eliminating, do not consume a large amount of heat energy and expensive reagent again, also can not cause the advantages such as pollution of environment, the carbon granules with oxidising process generation is very little, and the shortcoming that is difficult to remove can't be applied in factory at present.4, lime absorption method: it is to add lime with the organism in the adsorbent solution in mother liquor, gets rid of organic purpose to reach.This method was once tried out in certain factory, facts have proved: the not only weak effect of organism eliminating, and lime can generate calcium aluminate with the sodium aluminate reaction, causes alumina loss.5, ion exchange method: be that Bayer process solution is passed through ion exchange resin, get rid of organic purpose in the solution to reach, this method not only has the ion exchange resin regeneration difficulty, the problem that cost is high, and also organic eliminating amount is also very limited.
Summary of the invention:
The technical problem to be solved in the present invention provides a kind of sodium oxalate and gets rid of method effective, that flow process simple, less investment, the production and operation cost is low, alumina loss is few employing hyperconcentration method are got rid of sodium oxalate and carbonate from Bayer process solution, can overcome the deficiencies in the prior art.
Technical scheme of the present invention: this method is that the mother liquor with alumina system concentrates, make in the mother liquor causticization oxidation receive dense degree and reach 300～370g/l, send into the alumina producing system through the liquid that concentrates in the mother liquor of back, solid phase with 80～100 ℃ or dilute alkaline soln (because of dilute alkaline soln for containing alkali water of condensation or trade effluent, because of may containing certain alkali in these two kinds of water, it is 10～14% A solution that alkali concn is dissolved into carbonic acid sodium oxide concentration usually＜10g/l); A solution is sent into one section causticizing tank, and in one section causticizing tank, add lime or milk of lime, the amount that adds lime or milk of lime is 1.2～1.4 times of carbonic acid sodium oxide amount, and causticization got the B slurries in 2～4 hours under 75～95 ℃ condition, send into two sections causticizing tanks after the B slurries are cooled to 50～70 ℃, and in two sections causticizing tanks, add lime or milk of lime, the amount that adds lime or milk of lime is 0.5～1.0 times of sodium oxalate amount, causticization got the C slurries in 1.5～3.0 hours under 50～70 ℃ condition, the C slurries are sent into separator-scrubber, washing lotion is sent into the alumina producing system, and residue is delivered to the alumina laterite washing system.
Concentrating to adopt thickener to concentrate or add the high density liquid caustic and concentrate the mother liquor of alumina system.
When the mother liquor to alumina system concentrates, add sodium oxalate crystal seed or yellow soda ash crystal seed are arranged.
Sodium oxalate crystal seed coefficient is generally 0.5～1.2, and yellow soda ash crystal seed coefficient is generally 0.3～1.0.
Temperature when the mother liquor to alumina system concentrates is 103～110 ℃.
Temperature when the mother liquor to alumina system concentrates is 103～108 ℃.
It is water cooler that the B slurries are carried out the refrigerative system.
In order better to get rid of sodium oxalate and carbonate, the applicant has carried out great deal of experimental: following routine data are part test data of the present invention: wherein Nk represents causticization sodium oxide concentration (Na2Ok) in the solution, Nc represents carbonic acid sodium oxide concentration (Na2Oc) in the solution, NT represents full alkali concn (Na2OT) in the solution, and AO refers to alumina concentration in the solution (Al2O3).C is meant organic carbon content in the solution mesoxalic acid sodium (Na2C2O4), and Δ C has (deposition) rate (%) of separating out that refers to that C has.
Hyperconcentration crystal seed coefficient:
(1) with Nk=153g/LC
HaveThe mother liquor of=2.46～8.0g/L (hyperconcentration stoste) hyperconcentration can be found out the crystallization eduction rate of sodium oxalate, with stoste C during to the about 300g/L of Nk
HaveRaising and improve (as table 1):
Table 1
| Sequence number | The result name condition | ??NT??(g/L) | ??AO??(g/L) | ??Nk??(g/L) | ??Nc??(g/L) | ??C Have??(g/L) | ??Nc/NT??(％) | ??ΔC Have??(％) |
| ??1 | Before the hyperconcentration | ??163.8 | ??91.35 | ??153.0 | ??15.3 | ??2.46 | ??9.1 | ??66.89 |
| After the hyperconcentration | ??335.4 | ??191.38 | ??314.0 | ??21.4 | ??1.81 | ??6.4 | ||
| ??2 | Before the hyperconcentration | ??168.3 | ??91.35 | ??153.0 | ??15.3 | ??4.0 | ??9.1 | ??71.39 |
| After the hyperconcentration | ??331.2 | ??213.35 | ??309.0 | ??22.2 | ??2.51 | ??6.7 | ||
| ??3 | Before the hyperconcentration | ??168.3 | ??91.35 | ??153.0 | ??15.3 | ??6.0 | ??9.1 | ??73.36 |
| After the hyperconcentration | ??321.2 | ??181.84 | ??303.0 | ??18.2 | ??3.6 | ??5.7 | ||
| ??4 | Before the hyperconcentration | ??168.3 | ??91.35 | ??153.0 | ??15.3 | ??8.0 | ??9.1 | ??75.97 |
| After the hyperconcentration | ??312.6 | ??179.27 | ??298.0 | ??14.6 | ??4.31 | ??4.7 |
(2) with Nk=136.8g/L, C
HaveThe mother liquor of=1.44g/L (hyperconcentration stoste) carries out hyperconcentration, and along with the raising of hyper-concentration liquid Nk value, the eduction rate of sodium oxalate improves, and when hyper-concentration liquid Nk value reaches the 360g/L left and right sides, can find out that its eduction rate reaches the peak to value (as table 2)
Table 2
| Sequence number | The result name condition | ??NT??(g/L) | ??AO??(g/L) | ??Nk??(g/L) | ??Nc??(g/L) | ??C Have??(g/L) | ??Nc/NT??(％) | ?ΔC Have?(％) |
| ??1 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.44 | ??14.7 | ??70.3 |
| After the hyperconcentration | ??333.4 | ??172.04 | ??310.0 | ??23.4 | ??1.06 | ??7.0 | ||
| ??2 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.44 | ??14.7 | ??75.3 |
| After the hyperconcentration | ??352.6 | ??101.78 | ??335 | ??17.6 | ??0.98 | ??14.7 | ||
| ??3 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.44 | ??14.7 | ??81.3 |
| After the hyperconcentration | ??374.2 | ??200.19 | ??364.0 | ??10.2 | ??0.79 | ??2.7 | ||
| ??4 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.44 | ??14.7 | ??79.2 |
| After the hyperconcentration | ??399.0 | ??219.27 | ??386.0 | ??13.0 | ??0.91 | ??3.3 |
3, with Nk=136.8g/LC
HaveThe mother liquor of=1.80g/L (hyperconcentration stoste) carries out hyperconcentration, and result of study shows: at hyperconcentration stoste C
HaveUnder the conditions of higher, along with the raising of hyper-concentration liquid Nk value, the eduction rate of sodium oxalate improves equally, when hyper-concentration liquid Nk value reaches the 360g/L left and right sides, and its eduction rate peaking (as table 3)
Table 3
| Sequence number | The result name condition | ??NT??(g/L) | ??AO??(g/L) | ??Nk??(g/L) | ??Nc??(g/L) | ??C Have??(g/L) | ??Nc/NT??(％) | ?ΔC Have?(％) |
| ??1 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.80 | ??14.7 | ??71.7 |
| After the hyperconcentration | ??338.2 | ??160.19 | ??318.0 | ??20.2 | ??1.24 | ??6.0 | ||
| ??2 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.80 | ??14.7 | ??78.6 |
| After the hyperconcentration | ??350.2 | ??183.48 | ??336.0 | ??14.2 | ??1.07 | ??4.1 | ||
| ??3 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.80 | ??14.7 | ??82.8 |
| After the hyperconcentration | ??370.2 | ??179.93 | ??354.0 | ??16.2 | ??0.82 | ??4.4 | ||
| ??4 | Before the hyperconcentration | ??160.4 | ??82.9 | ??136.8 | ??23.6 | ??1.80 | ??14.7 | ??81.3 |
| After the hyperconcentration | ??390.2 | ??200.19 | ??376.0 | ??14.2 | ??1.05 | ??3.6 |
4, one section causticization is carried out in the crystallization that table 2 sequence number " 3 " is separated out, and result of study shows: at causticization stoste Nc=14%,
Under t=95 ℃ of T=3 hour the condition, C
HaveDeposition be 76.45%, its hyperconcentration precipitate is through one section causticization C
HaveDeposition (as the table .4)
Table 4
5, the causticization slip with test number in the table 4 " 7 "～" 9 " is cooled to 50～70 ℃, and presses
Add lime and carry out two sections causticizations, its C
HaveDeposition improves more than 10% on one section causticization basis.
Example: the slip of test number " 7 " is cooled to 50, and adds lime:
Work as lime adding amount:
Causticization 2 hours, the total causticizing efficiency of sodium oxalate (containing a section and two sections): 85.71%
Causticization 2 hours, the total causticizing efficiency of sodium oxalate (containing a section and two sections): 87.63%
6, add the test-results of crystal seed
Sequence number in the table 2 " 3 " and " 4 " condition are added the crystal seed test, and the result shows: add deposition (the Δ C that crystal seed not only can slightly improve the causticization sodium oxalate
Have), and make and separate out sodium oxalate and contain crystal water (H
2O
Knot) amount reduces significantly, adding crystal seed influences table (as table 5) to what sodium oxalate was separated out
Table 5
7, the causticization slag that the slip of the causticization slag of test number " 7 " in the table 4 (one section causticization) and this test is carried out two sections causticizations carries out solubility test again, its C as a result of two classes test
HaveThe basically identical of dissolution law again: the washing process alumina concentration is to C
HaveAgain the dissolution rate influence is little, and opposite temperature is to C
HaveDissolution rate again influence big, causticization slag organic carbon is solubility test result such as table 6 again).
Table 6
| Sequence number | ??Nk(g/L) | ??AO(g/L) | Temperature (℃) | Heavy molten C Have(％) |
| ??1 | ??4.0 | ??4.8 | ??70 | ??2.9 |
| ??2 | ??4.0 | ??4.8 | ??70 | ??3.1 |
| ??3 | ??4.0 | ??4.8 | ??80 | ??5.1 |
| ??4 | ??4.0 | ??4.8 | ??95 | ??7.5 |
| ??5 | ??6.0 | ??7.2 | ??60 | ??3.4 |
| ??6 | ??6.0 | ??7.2 | ??70 | ??4.2 |
| ??7 | ??6.0 | ??7.2 | ??80 | ??7.6 |
| ??8 | ??6.0 | ??7.2 | ??95 | ??10.8 |
| ??9 | ??8.0 | ??9.6 | ??60 | ??3.6 |
| ??10 | ??8.0 | ??9.6 | ??70 | ??7.1 |
| ??11 | ??8.0 | ??9.6 | ??80 | ??11.5 |
| Sequence number | ??Nk(g/L) | ??AO(g/L) | Temperature (℃) | Heavy molten C Have(％) |
| ??12 | ??8.0 | ??9.6 | ??95 | ??15.2 |
Compared with the prior art, this has following advantage:
1, hyperconcentration sodium oxalate crystallization eduction rate height: as with the mother liquor hyperconcentration during: do not add crystal seed C to 360g//l (NK)
HaveEduction rate reaches 81.3%, adds crystal seed (crystal seed coefficient 1.0) C
HaveEduction rate reaches 82.1%.); The hyperconcentration process is added crystal seed can make the content of crystal water in the hyperconcentration slag reduce to for 13% (content that does not add seeded crystallization water is about 30%).Show that promptly adding crystal seed makes the sodium oxalate advantages of good crystallization of separating out, particle is thicker, helps the separation and the washing of slag, has prevented that the slag of particulate from reentering solution system; The sodium oxalate crystallization of hyperconcentration is through one section causticization, and the deposition that sodium oxalate enters solid phase can reach 76%, and the total deposition (containing a section) of sodium oxalate can reach 85.7～87.6% after two sections causticizations; Sodium oxalate slag after causticization stability is better washed amount that dissolving again enters solution only 2.9～3.1% under 60～70 ℃ of temperature; Hyperconcentration stoste is behind hyperconcentration, one section causticization and separating, washing, and total elimination factor of its stoste mesoxalic acid sodium is about 57%; Hyperconcentration stoste is behind hyperconcentration, two sections causticizations and separating, washing, and total elimination factor of its stoste mesoxalic acid sodium is about 67%.
2, simple, the speed less investment of flow process; In order effectively to get rid of the sodium oxalate in the bayer liquor, this research only is that the flow process and the processing parameter of operations such as benefit alkali in original evaporation in the alumina producing, salt discharge (Na2CO3), causticization and the production are done further optimization and adjustment; Do not increase new operation, only increase a small amount of equipment; Hyperconcentration makes in the Baeyer solution crystallization separate out and generally selects high-efficiency evaporator for use, the process that the sodium oxalate crystallization is separated out be equally an evaporation of water concentration process meanwhile the salts such as yellow soda ash in the solution separate out together, so lifted the effect of killing three birds with one stone; The causticization that most alumina producer all need be provided with carbonate with separate, washing system.The causticization of mesoxalic acid sodium of the present invention with separate, wash and can altogether use a covering device with carbonate system.
Need be provided with all in alumina producer factory that strong liquid caustic (NaOH content 42～48%) stores and delivery system, the present invention can utilize original complete outfit, only strong caustic alkali need be changed into being transported to the hyperconcentration system and getting final product.Below what time find out: the method for this eliminating sodium oxalate is compared with additive method is preceding arranged, not only flow process simple and to the alumina producing system without any negative interaction, and construction investment economizes.
3, the production and operation cost is low; The present invention neither increases new operation and equipment, need not add any medicine and reagent (crystal seed recycles) at the sodium oxalate exclusion process, also none regeneration and recovery problem; Illustrate that thus enforcement of the present invention not only can not increase production cost, opposite to effectively sodium oxalate being got rid of from flow process, reached and eliminated the harm of sodium oxalate alumina producing, alumina production cost is decreased.
4, alumina loss is few: the crystallization of hyperconcentration sodium oxalate be with solution separating after dissolve causticization then, the solution in the crystal only enters causticization for some attached liquids, so the method alumina loss is less.
Description of drawings:
Fig. 1 is a production scheme of the present invention.
Embodiment:
Embodiment 1: as shown in Figure 1, earlier the mother liquor in the alumina producing system (Bayer process solution) is injected into hyperconcentration device 1 and carries out hyperconcentration, temperature when the mother liquor to alumina system concentrates is 103 ℃, after concentrating through hyperconcentration device 1, the causticization oxidation is received the degree of dense (Nk) and is reached 300g/l in the mother liquor.To be transported to separation tank 3 through hyperconcentration discharging pump 2 through the mother liquor (mother liquor and high density causticized alkali liquor mixed solution) that hyperconcentration device 1 is concentrated to prescribed value again, liquid is sent into the alumina producing system through separating overflow, separating underflow (solid phase) is delivered to salt filter 6 through underflow pump 5 and is filtered, filtrate (liquid) is also sent into the alumina producing system, solid phase (filter cake) is entered in the water dissolution groove 7, and to be dissolved into carbonic acid sodium oxide concentration with 80 ℃ of hot water or dilute alkaline soln be 10% A solution, used dilute alkaline soln is for containing alkali water of condensation or trade effluent, because of may containing certain alkali in these two kinds of water, alkali concn usually＜10g/l; A solution is transported to one section causticizing tank 9 through dissolving tank discharging pump 8, adds lime or milk of lime in one section causticizing tank 9, and the amount that adds lime or milk of lime is 1.2 times of carbonic acid sodium oxide amount, and causticization got the B slurries in 2 hours under 75 ℃ condition; The purpose that solid (mixture of Na2C2O4 and Na2CO3) after separating is carried out one section causticization be make yellow soda ash be converted into caustic alkali (Na2CO3+Ca (OH) 2=CaCO3 ↓+2NaOH) and as far as possible make sodium oxalate be converted into caoxalate Na2C2O4+Ca (OH) 2=CaC2O4 ↓+2NaOH).The B slurries are delivered to water cooler 11 through pump 10, water cooler 11 is a water cooler, at water cooler 11 internal cooling to 50 ℃ after pipeline is sent into two sections causticizing tanks 12, in two sections causticizing tanks, add lime or milk of lime, the amount that adds lime or milk of lime is 0.5 times of sodium oxalate amount, the all right one way or the other of sodium oxalate analyzed gained according to spot sampling, because of in present actual production, per tour will be carried out twice sampling analysis at least, therefore just can determine the content of organic carbon in the solution according to sampling analysis, just can calculate solution mesoxalic acid sodium amount according to the molecular formula Na2C2O4 of sodium oxalate.Causticization got the C slurries in 1.5 hours under 50 ℃ condition, and the C slurries are delivered to through pump 13 and separated and washing machine 14, and washing lotion is sent into the alumina producing system, washed the back slag and delivered to the alumina laterite washing system.
Embodiment 2: as shown in Figure 1, earlier the mother liquor in the alumina producing system (Bayer process solution) is injected into hyperconcentration device 1 and carries out hyperconcentration, temperature when the mother liquor to alumina system concentrates is 110 ℃, 108 ℃ of its preferred temperature, after concentrating through hyperconcentration device 1, the causticization oxidation is received the degree of dense (Nk) and is reached 370g/l in the mother liquor.Also can add an amount of high density causticized alkali liquor (42～48% NaOH), make causticization oxidation in mother liquor and the high density causticized alkali liquor mixed solution receive the degree of dense (Nk) and reach 370g/l in the outlet of hyperconcentration device; To be transported to separation tank 3 through hyperconcentration discharging pump 2 through the mother liquor (mother liquor and high density causticized alkali liquor mixed solution) that hyperconcentration device 1 is concentrated to prescribed value again, the alumina producing system is sent in the liquid separation overflow, separating underflow (solid phase) is delivered to salt filter 6 through underflow pump 5 and is filtered, filtrate (liquid) is also sent into the alumina producing system, solid phase (filter cake) is entered in the water dissolution groove 7, and to be dissolved into carbonic acid sodium oxide concentration with 100 ℃ of hot water or dilute alkaline soln be 14% A solution, A solution is transported to one section causticizing tank 9 through dissolving tank discharging pump 8, in one section causticizing tank 9, add lime or milk of lime, the amount that adds lime or milk of lime is 1.4 times of carbonic acid sodium oxide amount, and causticization got the B slurries in 4 hours under 95 ℃ condition; The purpose that solid (mixture of Na2C2O4 and Na2CO3) after separating is carried out one section causticization be make yellow soda ash be converted into caustic alkali (Na2CO3+Ca (OH) 2=CaCO3 ↓+2NaOH) and as far as possible make sodium oxalate be converted into caoxalate Na2C2O4+Ca (OH) 2=CaC2O4 ↓+2NaOH).The B slurries are delivered to water cooler 11 through pump 10, at water cooler 11 internal cooling to 70 ℃ after pipeline is sent into two sections causticizing tanks 12, in two sections causticizing tanks, add lime or milk of lime, the amount that adds lime or milk of lime is 1.0 times of sodium oxalate amount, causticization got the C slurries in 3.0 hours under 70 ℃ condition, the C slurries are delivered to through pump 13 and are separated and washing machine 14, and washing lotion is sent into the alumina producing system, wash the back slag and deliver to the alumina laterite washing system.
Embodiment 3: as shown in Figure 1, earlier the mother liquor in the alumina producing system (Bayer process solution) is injected into hyperconcentration device 1 and carries out hyperconcentration, temperature when the mother liquor to alumina system concentrates is 107 ℃, after concentrating through hyperconcentration device 1, the causticization oxidation is received the degree of dense (Nk) and is reached 360g/l in the mother liquor.Also can add an amount of high density causticized alkali liquor (42～48% NaOH), make causticization oxidation in mother liquor and the high density causticized alkali liquor mixed solution receive the degree of dense (Nk) and reach 360g/l in the outlet of hyperconcentration device; To be transported to separation tank 3 through hyperconcentration discharging pump 2 through the mother liquor (mother liquor and high density causticized alkali liquor mixed solution) that hyperconcentration device 1 is concentrated to prescribed value again, the alumina producing system is sent in the liquid separation overflow, separating underflow (solid phase) is delivered to salt filter 6 through underflow pump 5 and is filtered, filtrate (liquid) is also sent into the alumina producing system, solid phase (filter cake) is entered in the water dissolution groove 7, and to be dissolved into carbonic acid sodium oxide concentration with 90 ℃ of hot water or dilute alkaline soln be 12% A solution, A solution is transported to one section causticizing tank 9 through dissolving tank discharging pump 8, in one section causticizing tank 9, add lime or milk of lime, the amount that adds lime or milk of lime is 1.3 times of carbonic acid sodium oxide amount, and causticization got the B slurries in 3 hours under 85 ℃ condition; The purpose that solid (mixture of Na2C2O4 and Na2CO3) after separating is carried out one section causticization be make yellow soda ash be converted into caustic alkali (Na2CO3+Ca (OH) 2=CaCO3 ↓+2NaOH) and as far as possible make sodium oxalate be converted into caoxalate Na2C2O4+Ca (OH) 2=CaC2O4 ↓+2NaOH).The B slurries are delivered to water cooler 11 through pump 10, at water cooler 11 internal cooling to 60 ℃ after pipeline is sent into two sections causticizing tanks 12, in two sections causticizing tanks, add lime or milk of lime, the amount that adds lime or milk of lime is 0.8 times of sodium oxalate amount, causticization got the C slurries in 2.2 hours under 60 ℃ condition, the C slurries are delivered to through pump 13 and are separated and washing machine 14, and washing lotion is sent into the alumina producing system, wash the back slag and deliver to the alumina laterite washing system.Can add crystal seed in hyperconcentration device 1 by crystal seed pump 4 for the crystallization content that further improves sodium oxalate when mother liquor is carried out hyperconcentration: wherein the sodium oxalate crystal seed coefficient of Jia Ruing is generally 0.5～1.2, yellow soda ash crystal seed coefficient is generally 0.3～1.0, this measure not only makes salt crystallization eduction rate increase, and more efficiently is to make to separate out that crystal water content reduces significantly in the crystallization.
Claims (7)
1. method that adopts the hyperconcentration method from Bayer process solution, to get rid of sodium oxalate and carbonate, it is characterized in that: this method is that the mother liquor with alumina system concentrates, make in the mother liquor causticization oxidation receive dense degree and reach 300～370g/l, send into the alumina producing system through the liquid that concentrates in the mother liquor of back, it is 10～14% A solution that solid phase is dissolved into carbonic acid sodium oxide concentration with 80～100 ℃ or dilute alkaline soln; A solution is sent into one section causticizing tank, and in one section causticizing tank, add lime or milk of lime, the amount that adds lime or milk of lime is 1.2～1.4 times of carbonic acid sodium oxide amount, and causticization got the B slurries in 2～4 hours under 75～95 ℃ condition, send into two sections causticizing tanks after the B slurries are cooled to 50～70 ℃, and in two sections causticizing tanks, add lime or milk of lime, the amount that adds lime or milk of lime is 0.5～1.0 times of sodium oxalate amount, causticization got the C slurries in 1.5～3.0 hours under 50～70 ℃ condition, the C slurries are sent into separator-scrubber, washing lotion is sent into the alumina producing system, and residue is delivered to the alumina laterite washing system.
2. employing hyperconcentration method according to claim 1 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: concentrating can adopt thickener to concentrate or add the high density liquid caustic and concentrate the mother liquor of alumina system.
3. employing hyperconcentration method according to claim 1 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: adding when the mother liquor to alumina system concentrates has sodium oxalate crystal seed or yellow soda ash crystal seed.
4. employing hyperconcentration method according to claim 3 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: sodium oxalate crystal seed coefficient is generally 0.5～1.2, and yellow soda ash crystal seed coefficient is generally 0.3～1.0.
5. employing hyperconcentration method according to claim 1 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: the temperature when the mother liquor to alumina system concentrates is 103～110 ℃.
6. employing hyperconcentration method according to claim 5 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: the temperature when the mother liquor to alumina system concentrates is 103～108 ℃.
7. employing hyperconcentration method according to claim 1 is got rid of the method for sodium oxalate and carbonate from Bayer process solution, it is characterized in that: it is water cooler that the B slurries are carried out the refrigerative system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810305581A CN101734694B (en) | 2008-11-17 | 2008-11-17 | Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810305581A CN101734694B (en) | 2008-11-17 | 2008-11-17 | Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101734694A true CN101734694A (en) | 2010-06-16 |
| CN101734694B CN101734694B (en) | 2012-10-03 |
Family
ID=42458808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200810305581A Active CN101734694B (en) | 2008-11-17 | 2008-11-17 | Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101734694B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102259903A (en) * | 2011-06-20 | 2011-11-30 | 中国铝业股份有限公司 | Method for reducing content of sodium carbonate in alumina Bayer process solution |
| CN103787392A (en) * | 2014-02-12 | 2014-05-14 | 内蒙古蒙西鄂尔多斯铝业有限公司 | Method for producing aluminium oxide by using clinker dissolving-out liquid subjected to lime desilicication treatment |
| CN112499656A (en) * | 2020-12-16 | 2021-03-16 | 贵州华锦铝业有限公司 | Treatment method of discharged salt causticization slurry in alumina production |
| CN113149048A (en) * | 2021-03-26 | 2021-07-23 | 马朝扬 | Method for treating sodium oxalate solid waste residue in alumina production process |
| CN113184889A (en) * | 2021-03-22 | 2021-07-30 | 中国铝业股份有限公司 | Comprehensive utilization method of crystallized sodium oxalate slag in alumina production |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2686872B1 (en) * | 1992-02-05 | 1994-06-03 | Pechiney Aluminium | PROCESS FOR REMOVAL OF SODIUM OXALATE FROM BAYER CYCLE SODIUM ALUMINATE SOLUTIONS. |
| AUPP933499A0 (en) * | 1999-03-19 | 1999-04-15 | Worsley Alumina Pty Ltd | Process for the removal of oxalate and/or sulphate from bayer liquors |
| FR2794449B1 (en) * | 1999-06-04 | 2001-10-19 | Pechiney Aluminium | METHOD FOR PURIFYING SODIUM ALUMINATE LIQUORS CONTAINING SODIUM OXALATE FOR USE OF RESIDUES |
-
2008
- 2008-11-17 CN CN200810305581A patent/CN101734694B/en active Active
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102259903A (en) * | 2011-06-20 | 2011-11-30 | 中国铝业股份有限公司 | Method for reducing content of sodium carbonate in alumina Bayer process solution |
| CN102259903B (en) * | 2011-06-20 | 2013-06-05 | 中国铝业股份有限公司 | Method for reducing content of sodium carbonate in alumina Bayer process solution |
| CN103787392A (en) * | 2014-02-12 | 2014-05-14 | 内蒙古蒙西鄂尔多斯铝业有限公司 | Method for producing aluminium oxide by using clinker dissolving-out liquid subjected to lime desilicication treatment |
| CN103787392B (en) * | 2014-02-12 | 2015-02-04 | 内蒙古蒙西鄂尔多斯铝业有限公司 | Method for producing aluminium oxide by using clinker dissolving-out liquid subjected to lime desilicication treatment |
| CN112499656A (en) * | 2020-12-16 | 2021-03-16 | 贵州华锦铝业有限公司 | Treatment method of discharged salt causticization slurry in alumina production |
| CN113184889A (en) * | 2021-03-22 | 2021-07-30 | 中国铝业股份有限公司 | Comprehensive utilization method of crystallized sodium oxalate slag in alumina production |
| CN113184889B (en) * | 2021-03-22 | 2023-01-20 | 中国铝业股份有限公司 | Comprehensive utilization method of crystallized sodium oxalate slag in alumina production |
| CN113149048A (en) * | 2021-03-26 | 2021-07-23 | 马朝扬 | Method for treating sodium oxalate solid waste residue in alumina production process |
| CN113149048B (en) * | 2021-03-26 | 2022-08-26 | 马朝扬 | Method for treating sodium oxalate solid waste residues in alumina production process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101734694B (en) | 2012-10-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR20210010576A (en) | Method for recovering lithium hydroxide | |
| RU2564806C2 (en) | Method of producing ultrapure lithium carbonate from technical-grade lithium carbonate and apparatus therefor | |
| EP2403806B1 (en) | Removal of impurities in the production of crystalline sodium carbonate, bicarbonate, or sulfite | |
| CN101734694B (en) | Method for excluding sodium oxalate and carbonate from Bayer process solution by adopting ultra-concentration method | |
| CN103693665A (en) | Method for preparing high-purity aluminum oxide from fly ash | |
| CN109650413B (en) | Method and system for enriching lithium from sodium aluminate solution in alumina plant | |
| CN108439434A (en) | A kind of method and apparatus producing sodium bicarbonate | |
| CN105948306B (en) | A kind of pretreatment of coal gasification waste water exhaust gas and method of comprehensive utilization | |
| CN100572278C (en) | The method of expelling carbonate in a kind of alumina producing | |
| CN102574819B (en) | Water recycle in melamine production process | |
| CN112299461A (en) | Device and process for removing oxalate in sodium aluminate solution | |
| CN110028087B (en) | Method for reducing carbon-alkali concentration of system in alumina production process | |
| CN100450931C (en) | Carbonate-removing method in alumina production | |
| CN103818935A (en) | Method for separating potassium oxide from potassium-containing sodium aluminate solution | |
| CN102040225A (en) | Process for preparing precipitated white carbon black by adopting carbon dioxide for decomposition | |
| CN107572570A (en) | A kind of method that oxalates is removed in the washing lotion from Bayer process | |
| US3653848A (en) | Crystallization process | |
| CN112279277A (en) | System and method for high-end resource utilization of flue gas desulfurization by magnesium method | |
| CN109607582B (en) | Method and system for recovering magnesium salt from desulfurization wastewater | |
| CN216404066U (en) | Refining plant of industrial salt preparation salt solution | |
| CN214781303U (en) | Bromine salt recovery system | |
| CN105692658A (en) | Method for recycling potassium carbonate from aluminum oxide production process | |
| CN102796019A (en) | Method for environment-friendly clean production of high-purity ethylene diamine tetraacetic acid (EDTA) | |
| CN102259903B (en) | Method for reducing content of sodium carbonate in alumina Bayer process solution | |
| CN104803525A (en) | Method for processing high salinity wastewater and device thereof |
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 |