CN113213516A - Process for preparing sodium metaaluminate - Google Patents
Process for preparing sodium metaaluminate Download PDFInfo
- Publication number
- CN113213516A CN113213516A CN202110718697.6A CN202110718697A CN113213516A CN 113213516 A CN113213516 A CN 113213516A CN 202110718697 A CN202110718697 A CN 202110718697A CN 113213516 A CN113213516 A CN 113213516A
- Authority
- CN
- China
- Prior art keywords
- solution
- aluminum
- leaching
- smelting
- sodium
- 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.)
- Withdrawn
Links
Images
Classifications
-
- 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
- C01F7/0693—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 from waste-like raw materials, e.g. fly ash or Bayer calcination dust
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention belongs to the technical field of aluminum waste recovery, and relates to a method for preparing sodium metaaluminate. A process for preparing sodium metaaluminate comprises the following steps: (1) pretreating an aluminum waste material, adding alkali according to 0.75-1.50 times of the mass of aluminum slag, uniformly mixing, carrying out high-temperature smelting, and adding water to a smelting product for leaching to obtain a silicon-containing solution; (2) adding 2-10g/L desiliconization agent into the silicon-containing solution, leaching for a period of time, adding alkali solution into the leaching solution, stirring and evaporating to obtain crystals, and roasting the crystals to obtain sodium metaaluminate; the desiliconization agent is one or more of calcium oxide and magnesium oxide. In the process of desiliconizing the silicon-containing sodium aluminate, the invention researches the desiliconization effect, the desiliconization mechanism and the evaporation principle of calcium oxide, magnesium oxide and the mixture thereof, gets rid of the traditional cognition that the sodium aluminate solution is directly evaporated to obtain the sodium aluminate solid, and has innovation.
Description
Technical Field
The invention belongs to the technical field of aluminum waste recovery, and relates to a method for preparing sodium metaaluminate.
Background
Liquid aluminum formed at high temperature during smelting contacts with the inner surface of the furnace to form dross, which is called aluminum dross. The components of the aluminum slag generally consist of aluminum oxide, metallic aluminum, aluminum carbide, aluminum nitride and quartz and salt covering agents (NaCl-KCl-KF and the like). Every ton of raw aluminum is produced, 2% of aluminum slag is produced, and when secondary aluminum is used as a raw material, 10% of aluminum slag is produced.
The prior art for treating the aluminum ash mainly comprises a fire method process and a wet method process, wherein the fire method process mainly comprises an ash frying method, a rotary kiln molten salt method, a salt-free treatment process and the like. The acid leaching and the alkaline leaching in the wet process are widely applied, have the advantages of low cost, recyclable salt and the like, but also have the defects of complex waste liquid components, difficult treatment and the like. Compared with a wet process, the pyrogenic process has the characteristics of high recovery rate, convenience in subsequent treatment of slag and liquid and the like, but the characteristics of toxic gas, poor environment, much dust and the like generated in the pyrogenic process are always problems to be solved.
The prior art CN 108275708A discloses a secondary aluminum ash resource utilization method, which belongs to the technical field of metallurgical environmental protection, wherein the secondary aluminum ash is ground into powder and then is in contact with water vapor in a flushing manner under a high-pressure environment to obtain high-concentration aluminum ash, nitrogen and part of hydrogen fluoride are recovered, a suction filtration liquid obtained after the high-concentration aluminum ash is subjected to suction filtration is subjected to evaporation crystallization, most of chloride is recovered, a liquid phase obtained after the aluminum ash slag is flushed is subjected to evaporation crystallization, the residual chloride is recovered, the water vapor generated by the two evaporation crystallization processes is utilized in an online resource manner, the flushed solid phase is roasted first, the residual fluoride is recovered, a composite alkali solvent is added to remove impurities, the mixture is smelted, solid-liquid separation is carried out again, and the leachate is dried and then is calcined to obtain aluminum oxide.
However, there is no prior art for treating aluminum scrap to obtain sodium metaaluminate.
Disclosure of Invention
The invention aims to provide a process for preparing sodium metaaluminate by sintering aluminum slag, which aims to realize harmless treatment of the aluminum slag primarily while recycling aluminum resources in the aluminum slag.
In order to achieve the purpose, the invention adopts the following technical scheme:
a process for preparing sodium metaaluminate comprises the following steps:
(1) pretreating an aluminum waste material, adding alkali according to 0.75-1.50 times of the mass of aluminum slag, uniformly mixing, carrying out high-temperature smelting, and adding water to a smelting product for leaching to obtain a silicon-containing solution;
(2) adding 2-10g/L desiliconization agent into the silicon-containing solution, leaching for a period of time, adding alkali solution into the leaching solution, stirring and evaporating to obtain crystals, and roasting the crystals to obtain sodium metaaluminate;
the desiliconization agent is one or more of calcium oxide and magnesium oxide.
Preferably, the aluminum waste is one or more of aluminum slag, aluminum ash, nepheline and fly ash.
Preferably, the pretreatment is: crushing, grinding and drying the raw materials to obtain dry fine materials.
Preferably, the fine material has a particle size of less than 0.074mm and a moisture content of less than 1%.
Generally, the granularity of samples obtained from various places such as enterprises is not uniform, even can reach more than 12mm, the subsequent experiments such as alkali fusion and the like cannot be carried out due to too large granularity, and on the other hand, the smaller granularity can be fully contacted with sodium metaaluminate during alkali fusion, so that the reaction is more sufficient and efficient. The inventor of the invention uniformly mixes the materials of 20 meshes, 40 meshes, 80 meshes, 100 meshes and 200 meshes with sodium hydroxide by alkali fusion through a large number of exploratory experiments, and the experimental result proves that the effect of 200 meshes (0.074mm) is the best, the prepared sodium metaaluminate is the most, and the efficiency is the highest.
The water content is controlled to reduce the viscosity of subsequent evaporation products as much as possible and improve the yield of sodium metaaluminate.
Preferably, the alkali is one or more of sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide.
Preferably, the base is sodium hydroxide.
First, it is impossible for alkalis such as magnesium hydroxide and calcium hydroxide to react with aluminum products such as aluminum and aluminum oxide to form meta-aluminates, and therefore, potassium hydroxide is excluded from introducing K ion contamination to subsequent processes, and the solution using sodium hydroxide is optimal in view of the large cycle of the bayer process and some prior experience.
Preferably, the addition amount of the sodium hydroxide is 0.75-1.50 times of the mass of the aluminum slag.
Further preferably, the adding amount of the sodium hydroxide is 1.50 times of the mass of the aluminum slag.
From the experimental results of the present invention, that is, as shown in fig. 7, it can be seen that the peak of aluminum is gradually decreased and the peak of sodium metaaluminate is gradually increased as the ratio of soda residue increases, and in the XRD pattern, the area of the peak represents the ratio of the substance, and further, considering that a large amount of soda affects the corrosion and selection of the equipment, the ratio of soda residue is selected to be 1.50.
Preferably, the high-temperature smelting temperature is 400-800 ℃, and the smelting time is 0.5-2 h.
More preferably, the smelting temperature is 800 +/-5 ℃, and the smelting time is 1 +/-0.1 h.
From the experimental results of the present invention, i.e., fig. 5 and 6, it can be seen from fig. 5 that the peak of aluminum is gradually decreased and the peak of sodium metaaluminate is gradually increased with the increase of temperature, i.e., the formation rate of sodium metaaluminate is higher with the increase of temperature. However, the temperature is selected to be 800 + -5 deg.C, considering that higher temperature can affect the corrosion effect of the volatilization of sodium hydroxide on the equipment.
As can be seen from FIG. 6, the reaction time of 1h is the best, and as the time is increased, sodium metaaluminate reacts with sodium hydroxide to produce sodium aluminum silicon double salt (Na)1.95Al1.95Si0.05O4) And the yield of sodium metaaluminate is influenced.
Preferably, the temperature for leaching the smelting product by adding water is 20-60 ℃, the time required by a leaching experiment is 3-5 h, and the liquid-solid ratio of the leaching experiment is set to be 5-10.
Leaching the leached slag at normal temperature for a period of time, dissolving the solid sodium metaaluminate, sodium silicate and the like in water in the leaching process, and separating the solid sodium metaaluminate, sodium silicate and the like from other insoluble substances, such as calcium oxide, magnesium oxide, iron oxide and the like to obtain a sodium silicoaluminate solution.
Preferably, the desiliconization agent is a mixture of calcium oxide and magnesium oxide.
In the sodium aluminosilicate solution, silicon mainly exists in the form of sodium silicate, the silicon content index is 20-100, and silicon impurities in the solution can be removed in the form of hydrated garnet by adding a desiliconization agent to form a precipitate of sodium-aluminum-silicon double salt to remove the silicon in the solution; on the other hand, the influence of solution gel and silicon on equipment in the evaporation process can be prevented.
Preferably, in the desiliconization agent, the mass ratio of calcium oxide to magnesium oxide is (2-4): 1.
But different desiliconizing agents have different desiliconizing effects on the solution, wherein the mixture of calcium oxide and magnesium oxide has the best desiliconizing effect on the sodium aluminate solution.
The desilication rate of the single calcium oxide increases with the addition amount of the single calcium oxide within a certain range, but the single calcium oxide causes more loss. Whereas magnesium oxide alone is not effective for desiliconizing sodium aluminosilicate solutions because the substance formed by the reaction is (Mg)4Al2)(OH)12CO3(H2O)3Without the participation of silicon, silicon element can not be fixed.
In contrast to magnesium oxide, the substance formed by the reaction of calcium oxide is Ca3Al2(SiO4)3And 3 CaO. Al2O3. Therefore, silicon can be removed quickly.
Preferably, the leaching temperature of adding a certain amount of desiliconization agent into the silicon-containing solution is 80 +/-2 ℃, and the leaching time is 2 +/-0.1 h.
Preferably, the amount of the alkali solution added in step (2) is 0.4 to 2 mol.
As shown in fig. 1, the evaporation principle diagram prepared by the inventor of the present invention, in the evaporation system of the present invention, the α k value in the solution is adjusted by adding different amounts of sodium hydroxide, so as to obtain different evaporation products, i.e., sodium metaaluminate and aluminum hydroxide. That is, the amount of sodium hydroxide added is too small to obtain aluminum hydroxide by evaporation and sodium metaaluminate. However, too high a concentration of sodium hydroxide also results in too low a solubility of sodium metaaluminate and too low a yield.
Preferably, the alkali solution is a sodium hydroxide solution.
The introduction of other bases will increase new ionic contamination, consistent with the previous step (1), with sodium base.
Preferably, the evaporation temperature is 80. + -. 5 ℃.
As shown in FIG. 1, in the sodium aluminate solution, zone I represents a stage where neither sodium metaaluminate nor aluminum hydroxide is saturated, zones II and III represent supersaturated solutions of aluminum hydroxide and sodium metaaluminate, respectively, and zone IV represents a supersaturated stage of gibbsite and hydrated sodium metaaluminate. The OB line represents the solubility curve of gibbsite in sodium hydroxide solution, the solubility of alumina increases slowly and then sharply with increasing sodium hydroxide concentration, the BC line represents the solubility curve of 2.5 hydrated sodium aluminate in sodium hydroxide solution, and the solubility of 2.5 hydrated sodium aluminate decreases with increasing sodium hydroxide concentration. The zone I is larger and larger along with the increase of the temperature, which means that the sodium aluminate and the aluminum hydroxide are more difficult to saturate and evaporate products, and the lower temperature is difficult to increase the evaporation rate, and the inventor finds that 80 ℃ is the optimal condition through multiple exploratory experiments.
Preferably, the roasting temperature is 200 +/-5 ℃, and the roasting time is 1 +/-0.1 h.
The evaporation product has viscosity, and the calcination product after removing the crystal water has no viscosity characteristic by adding the evaporation product into a muffle furnace for calcination, and the calcination temperature is 200 +/-5 ℃ to achieve the effect.
The invention is further explained below:
the key point of the technology of the invention is that stable sodium metaaluminate finished products, not aluminum hydroxide, are obtained through process adjustment. The invention researches the removing effect of different desiliconizing agents on the sodium aluminate solution containing silicon and the evaporation research of the sodium aluminate solution to obtain different evaporation products.
The main reactions involved in the invention are:
adding CaO into a silicon-containing sodium aluminate solution:
CaO+H2O→Ca(OH)2
3Ca(OH)2+2NaAl(OH)4→3CaO·Al2O3·6H2O↓+2NaOH+3H2O
the Si existing form in the solution:
calcium oxide desilication reaction:
can be simplified as follows:
3CaO·Al2O3·6H2O+Na2O·Al2O3·2SiO2·2H2O→3CaO·Al2O3·xSiO2·(6-
2x)H2O↓+2NaAl(OH)4
adding MgO into the sodium silicate-containing solution:
MgO+H2O→Mg(OH)2
4Mg(OH)2+2NaAl(OH)4+Na2CO3+3H2O→(Mg4Al2)(OH)12CO3(H2O)3when ↓ +4NaOH MgO was mixed with CaO, MgO was preferentially mixed with NaAl (OH)4NaAl (OH) which reacts less CaO4So as to achieve the effect of reducing the loss, and in addition, MgO can promote the desilication reaction of calcium oxide.
The invention belongs to a fire method-wet method combined treatment process, is innovative, has flexibility, can obtain different evaporation products (sodium metaaluminate or aluminum hydroxide) by regulating the alpha k value of a sodium aluminate solution, aluminum-containing resources of non-bauxite such as aluminum slag, aluminum ash and the like, is listed as HW48 hazardous waste in 2021 by China, can treat the aluminum slag and the aluminum ash to achieve the aim of environmental protection on one hand, has the aluminum content of more than 50 percent, and has economic benefit by treating alkali fusion, desiliconization, evaporation and the like to obtain a product (sodium metaaluminate) with high added value. In the process of desiliconizing the silicon-containing sodium aluminate, the invention researches the desiliconization effect, the desiliconization mechanism and the evaporation principle of calcium oxide, magnesium oxide and the mixture thereof, gets rid of the traditional cognition that the sodium aluminate solution is directly evaporated to obtain the sodium aluminate solid, and has innovation.
Compared with the prior art, the invention has the following beneficial effects:
compared with the Bayer process and the sintering process in the prior art, the wet treatment process of the Bayer process and the fire treatment process of the sintering process belong to a fire-wet combined treatment process, and because the aluminum slag and the aluminum ash are byproducts generated in the aluminum processing industry, the aluminum slag and the aluminum ash contain a large amount of inert alumina, namely alpha-Al 2O 3. The traditional Bayer process is weak in acid-base leaching of inert alumina, the leaching rate can reach 40% at most even if a pressurized kettle is used, and the leaching rate is high in alkali, high temperature and high pressure.
Drawings
FIG. 1 is a schematic diagram of evaporation;
FIG. 2 is a flow chart of the process of the present invention;
FIG. 3 shows an aluminum slag raw material (A) and a molten slag (B) obtained by melting;
FIG. 4 is an XRD analysis chart of the aluminum slag raw material;
FIG. 5 is a XRD analysis temperature diagram of the slag;
FIG. 6 is a time chart of XRD analysis of the slag;
FIG. 7 is a XRD analysis proportioning diagram of the smelting slag;
FIG. 8 is an XRD pattern of the leaching residue in step (1);
FIG. 9 is an XRD pattern of the desiliconized leached residues;
FIG. 10 is an XRD pattern of the crystal;
FIG. 11 is a thermogravimetric analysis of a crystal.
Detailed Description
Example 1
A process for preparing sodium metaaluminate according to the flow shown in figure 2 comprises the following steps:
(1) crushing, grinding and drying an aluminum slag raw material (shown in figure 3A), analyzing element content of a dried representative sample, and performing thermodynamic calculation on a metallurgical process; the result of the semi-quantitative XRD analysis of the raw material aluminum slag is shown in FIG. 4, wherein the Al content in the raw material aluminum slag is 52.78%, and the balance is silicon oxide, magnesium metaaluminate and the like.
Uniformly mixing 100g of dried fine-grained aluminum slag with sodium hydroxide according to the mass ratio of 0.25-1.5 of the alkaline slag, and preparing 250g of smelting raw material;
(2) adding 250g of the smelting raw material obtained in the step (1) into a 300ml ceramic crucible, sending the crucible to a muffle furnace, and smelting for 0.5-2.0h under the smelting condition of 800 ℃ and 500 ℃ by adjusting the temperature, wherein the obtained smelting slag is shown in FIG. 3B;
(3) carrying out XRD semi-quantitative analysis on the smelting slag obtained in the step (2) by using jade6.5 software, wherein the content of sodium metaaluminate is 92.33%; as shown in fig. 5, it can be seen from fig. 5 that the peak of aluminum is gradually decreased and the peak of sodium metaaluminate is gradually increased as the temperature is increased, that is, the formation rate of sodium metaaluminate is higher as the temperature is increased. However, the temperature is selected to be 800 ℃ in consideration of the influence of higher temperature on the corrosion of the equipment caused by the volatilization of sodium hydroxide.
As shown in FIG. 6, it can be seen from FIG. 6 that the reaction time of 1h is the best effect, and as the time is increased, sodium metaaluminate reacts with sodium hydroxide to produce sodium aluminum silicon double salt (Na1.95Al1.95Si0.05O4), which affects the yield of sodium metaaluminate.
As shown in FIG. 7, it can be seen from FIG. 7 that the aluminum peak is gradually decreased and the sodium metaaluminate peak is gradually increased as the ratio of soda ash is increased, and the area of the peak in the XRD pattern represents the ratio of the substance, and further, considering that a large amount of soda ash affects the corrosion and selection of the equipment, the ratio of soda ash is 1.50 in combination.
The parameters of the integrated design are shown in table 1, and the specific data are also shown in table 2.
TABLE 1 parameter table
| Serial number | Raw material mass/g | Alkali (NaOH)/g | Roasting temperature/. degree.C | Calcination time/ |
| 1 | 20 | 20 | 400 | 1 |
| 2 | 20 | 20 | 500 | 1 |
| 3 | 20 | 20 | 600 | 1 |
| 4 | 20 | 20 | 700 | 1 |
| 5 | 20 | 20 | 800 | 1 |
| 6 | 20 | 20 | 800 | 0.5 |
| 7 | 20 | 20 | 800 | 1.5 |
| 8 | 20 | 20 | 800 | 2 |
| 9 | 20 | 5 | 800 | 1 |
| 10 | 20 | 10 | 800 | 1 |
| 11 | 20 | 15 | 800 | 1 |
| 12 | 20 | 25 | 800 | 1 |
| 13 | 20 | 30 | 800 | 1 |
TABLE 2 results of adjusting parameters
Comprehensively considering, selecting the optimal process with the ratio of alkali to slag of 1.5, the smelting temperature of 800 ℃ and the smelting time of 1.0 h.
(4) Grinding the smelting slag obtained by smelting at the smelting temperature of 800 ℃ and the smelting time of 1.0h to be less than 0.074mm in ratio of alkali slag to 1.5, weighing 30g of the smelting slag, adding the smelting slag into a 500ml beaker, adding 200ml of water, leaching for 4h at the temperature of 25 ℃, performing solid-liquid separation by using a suction filter after leaching to obtain leaching solution 1 and leaching slag 1, and performing XRD (X-ray diffraction) test on the leaching slag 1, wherein the leaching slag 1 is analyzed to be magnesium oxide and calcium carbonate as shown in figure 8;
(5) adding 2g/L calcium oxide into the leaching solution 1 obtained in the step (4), leaching for 2h at 80 ℃, removing silicon in the solution to obtain a leaching solution 2 and leaching residues 2, and carrying out XRD (X-ray diffraction) test on the leaching residues 2, wherein the leaching residues 2 are analyzed to be hydrated garnet and calcium-aluminum crystals as shown in figure 9; respectively testing the aluminum ion concentration and the silicon ion concentration in the leachate 1 obtained in the step (4) and the leachate 2 after desiliconization by using ICP-OES, and finding that the silicon concentration of the leachate 1 is removed from 0.84g/L to 0.21g/L of the leachate 2, the removal rate reaches 75%, the aluminum concentration of the leachate 1 is lost from 17.82g/L by calcium oxide reaction to 16.72g/L of the leachate 2, and the loss rate reaches 6.17%;
(6) adding 24.4g of sodium hydroxide into the leaching solution 2 obtained in the step (5), and evaporating at 80 ℃ in a magnetic heating stirrer to finally obtain 49.8g of evaporation product; the evaporation product was subjected to XRD test, as shown in FIG. 10, and it was confirmed that sodium metaaluminate water crystals were obtained. Thermogravimetric analysis of the evaporation product, as shown in fig. 11, revealed that a peak was observed at around 200 c, at which it is highly likely that crystal water could be maximally lost.
(7) Adding the evaporation product obtained in the step (6) into a ceramic crucible, and roasting in a muffle furnace at 200 ℃ for 1h to obtain 45.8g of sodium metaaluminate product;
example 2
A process for preparing sodium metaaluminate comprises the following steps:
(1) crushing, grinding and drying the aluminum slag raw material according to the flow shown in the figure 2, analyzing the element content of a dried representative sample, and carrying out thermodynamic calculation on the metallurgical process;
uniformly mixing 100g of dried fine-grained aluminum slag with sodium hydroxide according to the mass ratio of 1.5 to prepare 250g of smelting raw material;
(2) adding 250g of the smelting raw material obtained in the step (1) into a 300ml ceramic crucible, conveying to a muffle furnace, and smelting for 1.0h under the smelting condition of adjusting the temperature to 800 ℃;
(3) grinding the smelting slag obtained in the step (2) to be less than 0.074mm, weighing 30g of smelting slag, adding the smelting slag into a 500ml beaker, adding 200ml of water, leaching for 4 hours at 25 ℃, and performing solid-liquid separation by using a suction filter after leaching to obtain leachate and leaching slag;
(4) adding 6g/L calcium oxide into the leachate obtained in the step (3), leaching for 2h at 80 ℃, removing silicon in the solution, respectively testing the aluminum and silicon ion concentrations in the solution by using ICP-OES on the leachate obtained in the step (3) and the leachate after desiliconization, and finding that the silicon concentration of the leachate 1 is removed from 0.84g/L to 0.08g/L of the leachate 2, the removal rate reaches 90.48%, the aluminum concentration of the leachate 1 is reacted by the calcium oxide from 17.82g/L and lost to 14.22g/L of the leachate 2, and the loss rate reaches 20.20%; however, a large amount of calcium oxide not only increases the desiliconization effect, but also the excess calcium oxide reacts with sodium metaaluminate to generate calcium-aluminum crystals and lose the quality of aluminum oxide.
(3) Adding 24.4g of sodium hydroxide into the leachate 2 obtained in the step (2), and evaporating in a magnetic heating stirrer to finally obtain 40.92g of an evaporation product;
adding the evaporation product obtained in the step (6) into a ceramic crucible, and roasting in a muffle furnace at 200 ℃ for 1h to obtain 38.82g of sodium metaaluminate product;
example 3
The method comprises the following steps:
(1) this step was identical to (1) to (3) of example 2;
(2) adding 6g/L calcium oxide and 2g/L magnesium oxide into the leachate obtained in the step (1) in the example 3, leaching for 2 hours at 80 ℃, removing silicon in the solution, respectively testing the concentrations of aluminum and silicon ions in the solution by using ICP-OES on the leachate obtained in the step (1) and the leachate after desiliconization, and finding that the silicon concentration of the leachate 1 is removed from 0.84g/L to 0.03g/L of the leachate 2, the removal rate reaches 96.43 percent, the aluminum concentration of the leachate 1 is lost from 17.82g/L by calcium oxide reaction to 15.71g/L of the leachate 2, and the loss rate reaches 11.84 percent;
when added into a sodium aluminate solution, calcium oxide reacts with the sodium aluminate to generate calcium aluminum crystals, sodium silicate in the solution reacts with the sodium aluminate to generate sodium aluminum silicon double salt, the double salt reacts with the calcium aluminum crystals to generate hydrated garnet with lower solubility product to achieve the desiliconization effect, and the addition of a certain amount of magnesium oxide promotes the reaction to generate, so that the desiliconization rate is increased, on the other hand, the magnesium oxide also reacts with the sodium aluminate to inhibit the reaction of the calcium oxide and the sodium aluminate, and the effect of reducing the loss rate is achieved.
(3) Adding 24.4g of sodium hydroxide into the leachate after desiliconization treatment, and evaporating in a magnetic heating stirrer to finally obtain 43.56g of an evaporation product;
(4) adding the evaporation product obtained in the step (6) into a ceramic crucible, and roasting in a muffle furnace at 200 ℃ for 1h to obtain 42.77g of sodium metaaluminate product;
example 4
The method comprises the following steps:
(1) this step was identical to (1) to (4) of example 1;
(2) leaching the leachate obtained in the step (1) and 2g/L magnesium oxide at 80 ℃ for 2h to remove silicon in the solution, testing the concentrations of aluminum and silicon ions in the solution by respectively using ICP-OES (inductively coupled plasma-optical emission spectrometry) on the leachate 1 obtained in the step (4) and the treated leachate 2, and finding that the silicon concentration of the leachate 1 is removed from 0.84g/L to 0.83g/L of the leachate 2, the removal rate is only 1.19%, the aluminum concentration of the leachate 1 is reacted by calcium oxide from 17.82g/L to be lost to 16.77g/L of the leachate 2, and the loss rate reaches 5.89%;
(3) adding 24.4g of sodium hydroxide into the leachate 2 obtained in the step (2), and evaporating in a magnetic heating stirrer to finally obtain 44.38g of an evaporation product;
(4) adding the evaporation product obtained in the step (6) into a ceramic crucible, and roasting in a muffle furnace at 200 ℃ for 1h to obtain 43.41g of sodium metaaluminate product;
example 5
The method comprises the following steps:
(1) this step was identical to (1) to (2) of example 3;
(2) evaporating the desiliconized leachate in a magnetic heating stirrer without adding sodium hydroxide to obtain 19.16g of an evaporation product;
(3) and (3) adding the evaporation product obtained in the step (2) into a ceramic crucible, and roasting in a muffle furnace at the temperature of 200 ℃ for 1h to obtain 17.82g of an aluminum hydroxide product.
Example 6
The method comprises the following steps:
(1) this step was identical to (1) to (2) of example 3;
(2) adding 5.0g of sodium hydroxide into the desiliconized leaching solution, and evaporating in a magnetic heating stirrer to finally obtain 24.77g of evaporation product;
(3) and (3) adding the evaporation product obtained in the step (2) into a ceramic crucible, and roasting in a muffle furnace at the temperature of 200 ℃ for 1h to obtain 23.78g of sodium metaaluminate product.
The above examples are only for describing the preferred embodiments of the present invention, and do not limit the scope of the claimed invention, and various modifications made by the skilled in the art according to the technical solution of the present invention should fall within the scope of the invention defined by the claims without departing from the spirit of the present invention.
Claims (10)
1. A process for preparing sodium metaaluminate is characterized by comprising the following steps:
(1) pretreating an aluminum waste material, adding alkali according to 0.75-1.50 times of the mass of aluminum slag, uniformly mixing, carrying out high-temperature smelting, and adding water to a smelting product for leaching to obtain a silicon-containing solution;
(2) adding 2-10g/L desiliconization agent into the silicon-containing solution, leaching for a period of time, adding alkali solution into the leaching solution, stirring and evaporating to obtain crystals, and roasting the crystals to obtain sodium metaaluminate;
the desiliconization agent is one or more of calcium oxide and magnesium oxide.
2. The process according to claim 1, characterized in that the pre-treatment is: crushing, grinding and drying the raw materials to obtain dry fine materials; preferably, the fine material has a particle size of less than 0.074mm and a moisture content of less than 1%.
3. The process according to claim 1, wherein the alkali is one or more of sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide; preferably, the base is sodium hydroxide.
4. The process as claimed in claim 3, wherein the sodium hydroxide is added in an amount of 0.75-1.50 times the mass of the aluminum slag.
5. The process as claimed in claim 1, wherein the high temperature smelting temperature is 400-800 ℃, and the smelting time is 0.5-2 h; preferably, the smelting temperature is 800 +/-5 ℃, and the smelting time is 1 +/-0.1 h.
6. The process as claimed in claim 1, wherein the desiliconizing agent is a mixture of calcium oxide and magnesium oxide, and preferably, the mass ratio of calcium oxide to magnesium oxide in the desiliconizing agent is (2-4): 1.
7. The process as claimed in claim 1, wherein the leaching temperature of the desiliconization agent added to the solution containing silicon is 80 ± 2 ℃ and the leaching time is 2 ± 0.1 h.
8. The process according to claim 1, wherein the amount of the alkali solution added in the step (2) is 0.4 to 2 mol; preferably, the alkali solution is a sodium hydroxide solution.
9. The process according to claim 1, wherein the evaporation temperature is 80 ± 2 ℃.
10. The process according to any one of claims 1 to 9, wherein the calcination temperature is 200 ± 5 ℃ and calcination time is 1 ± 0.1 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110718697.6A CN113213516A (en) | 2021-06-28 | 2021-06-28 | Process for preparing sodium metaaluminate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110718697.6A CN113213516A (en) | 2021-06-28 | 2021-06-28 | Process for preparing sodium metaaluminate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113213516A true CN113213516A (en) | 2021-08-06 |
Family
ID=77080978
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110718697.6A Withdrawn CN113213516A (en) | 2021-06-28 | 2021-06-28 | Process for preparing sodium metaaluminate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113213516A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114988443A (en) * | 2022-06-02 | 2022-09-02 | 中南大学 | Method for recovering aluminum oxide from aluminum-rich slag |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105271327A (en) * | 2014-09-26 | 2016-01-27 | 昆明冶金研究院 | Method for harmless disposal and recycling of aluminum ash |
-
2021
- 2021-06-28 CN CN202110718697.6A patent/CN113213516A/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105271327A (en) * | 2014-09-26 | 2016-01-27 | 昆明冶金研究院 | Method for harmless disposal and recycling of aluminum ash |
Non-Patent Citations (2)
| Title |
|---|
| 刘桂华等: ""氧化镁在铝酸钠溶液脱硅中的反应行为"", 《中国有色金属学报》 * |
| 姚静武等: ""Al（OH）3碱解法制取铝酸钠结晶工艺研究"", 《矿产保护与利用》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114988443A (en) * | 2022-06-02 | 2022-09-02 | 中南大学 | Method for recovering aluminum oxide from aluminum-rich slag |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109179464A (en) | A kind of method of Quadratic aluminum dust high-efficiency cleaning resource utilization | |
| Yao et al. | An environmental-friendly process for dissociating toxic substances and recovering valuable components from spent carbon cathode | |
| CN113278808B (en) | Method for recovering various solid waste materials in aluminum smelting process in linkage manner | |
| WO1992012268A1 (en) | Recovery of aluminium and fluoride values from spent pot lining | |
| Wang et al. | Extraction of alumina from fly ash by ammonium hydrogen sulfate roasting technology | |
| CN115216645B (en) | Method for extracting lithium from electrolytic aluminum waste residue by mixed salt calcination | |
| Ma et al. | A cleaner approach for recovering Al and Ti from coal fly ash via microwave-assisted baking, leaching, and precipitation | |
| CN113443643B (en) | Method for cooperatively treating aluminum ash, carbon slag and desulfurized gypsum slag | |
| KR20090004036A (en) | Manufacturing methods of magnesium compounds from waste mgo-c refractories | |
| KR20150114383A (en) | System and method for rare earths extraction | |
| CN110482503A (en) | A kind of method of Quadratic aluminum dust comprehensive utilization of resources | |
| US4474736A (en) | Treatment of aluminous materials | |
| CN111647751B (en) | Method for enriching platinum group metals from automobile waste catalyst | |
| CN114606387A (en) | Wet-process and pyrogenic-process combined comprehensive recovery method for arsenic-alkali residue | |
| CN114737066B (en) | Method for extracting lithium from leaching residues of lithium ores | |
| CN113213516A (en) | Process for preparing sodium metaaluminate | |
| WO2011127671A1 (en) | Method for extracting aluminium hydroxide and alumina from byproduct obtained during refining metal magnesium with aluminium or aluminium alloy as reducer | |
| CN101100304A (en) | Method for preparing aluminum oxide from low aluminum-silicon ratio aluminum-containing mineral | |
| CN114620752A (en) | Pretreatment method of secondary aluminum ash, water purifying agent and application | |
| Singh et al. | Studies on process for conversion of waste aluminium dross into value added products | |
| CN112546529A (en) | Process for realizing dealkalization of high-alkalinity red mud by utilizing industrial waste residues and waste gases | |
| CN216191117U (en) | Reaction system for recycling aluminum oxide in aluminum-based hazardous waste | |
| CN113697834A (en) | Method for preparing Friedel salt by extracting titanium slag and Friedel salt | |
| US2793933A (en) | Method of producing lithium salts from lithium minerals | |
| CN112279284B (en) | Method for comprehensively utilizing high-sulfur bauxite and Bayer process red mud |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20210806 |