CN113213499B - Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash - Google Patents

Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash Download PDF

Info

Publication number
CN113213499B
CN113213499B CN202110645309.6A CN202110645309A CN113213499B CN 113213499 B CN113213499 B CN 113213499B CN 202110645309 A CN202110645309 A CN 202110645309A CN 113213499 B CN113213499 B CN 113213499B
Authority
CN
China
Prior art keywords
fly ash
desilication
boehmite
tobermorite
reaction
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.)
Active
Application number
CN202110645309.6A
Other languages
Chinese (zh)
Other versions
CN113213499A (en
Inventor
周慎谦
欧阳忠凯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hunan Vision New Material Technology Co ltd
Original Assignee
Hunan Vision New Material Technology Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hunan Vision New Material Technology Co ltd filed Critical Hunan Vision New Material Technology Co ltd
Priority to CN202110645309.6A priority Critical patent/CN113213499B/en
Publication of CN113213499A publication Critical patent/CN113213499A/en
Application granted granted Critical
Publication of CN113213499B publication Critical patent/CN113213499B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/20—Silicates
    • C01B33/32—Alkali metal silicates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/20—Silicates
    • C01B33/26—Aluminium-containing silicates, i.e. silico-aluminates
    • 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
    • C01F11/00—Compounds of calcium, strontium, or barium
    • C01F11/18—Carbonates
    • C01F11/181—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by control of the carbonation conditions
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

A method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash comprises the following steps: a. mixing the fly ash with sodium hydroxide solution, performing hydrothermal reaction for 2 times, and then adding a impurity removing agent and a filter aid for reaction to obtain water glass and desilication fly ash; b. adding water, quicklime and sodium hydroxide solution into the desilication fly ash, and performing hydrothermal reaction for 2 times to obtain sodium metaaluminate crude liquid and tobermorite; c. the coarse sodium metaaluminate solution and quicklime milk are subjected to secondary desilication reaction, oxalic acid is added, and CO is introduced 2 The gas reacts to obtain sodium carbonate solution and boehmite filter cake; carrying out causticization reaction on the sodium carbonate solution to obtain calcium carbonate; soaking the boehmite filter cake, and then carrying out solid-liquid separation to obtain boehmite. The invention has low energy consumption, low cost, high extraction rate of silicon and aluminum elements and high utilization rate.

Description

Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash
Technical Field
The invention relates to a method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash, in particular to a method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash.
Background
Fly ash is one of the largest industrial solid wastes discharged and stored in the world at present. The dry fly ash is typically gray or off-white and the aqueous fly ash is off-black. The main composition of oxide in fly ash is SiO 2 、Al 2 O 3 、Fe 2 O 3 、CaO、MgO、TiO 2 、K 2 O、Na 2 O, mnO and SO 3 Etc., wherein SiO is 2 And Al 2 O 3 The content of (2) is more than 70 wt%. The comprehensive development and utilization of aluminum and silicon elements in fly ash resources are beneficial to the protection and development of local environment, and are circular economy industry with important strategic significance.
How to extract aluminum and silicon elements from fly ash, technological workers have conducted a great deal of experiments and researches.
CN101125656a discloses a method for extracting silicon and then extracting aluminum from fly ash, which comprises leaching fly ash with NaOH solution with mass concentration of more than 40%, leaching silicon therein in the form of sodium silicate, separating to obtain sodium silicate solution and alkaline leaching slag with aluminum-silicon ratio of not less than 2, and leaching siliconEvaporating sodium silicate solution to obtain sodium silicate solution with different concentration, or preparing white carbon black by carbon component method, and producing Al (OH) by alkaline leaching residue by soda lime sintering method or limestone sintering method 3 And further produces alumina.
CN102249253B discloses a method for producing alumina and co-producing active calcium silicate by using high-alumina fly ash, which comprises the steps of firstly, reacting with sodium hydroxide solution to perform pre-desilication to obtain liquid-phase desilication liquid and solid-phase desilication fly ash; lime milk is added into desilication liquid for causticizing reaction to obtain active calcium silicate, limestone and sodium carbonate solution are added into desilication slag to prepare qualified raw slurry, the qualified raw slurry is baked into clinker, the clinker is dissolved out to obtain sodium aluminate crude liquid, and metallurgical grade alumina is obtained after desilication, carbon separation, seed separation, roasting and other procedures.
When the two methods are used, although the phase characteristics of the fly ash are considered, the method of firstly extracting silicon and then extracting aluminum is adopted, the method of extracting aluminum oxide from desilication slag adopts roasting alkali dissolution, and the extraction rate of the aluminum oxide can reach more than 85 percent, the method can produce new solid waste while the fly ash is consumed, and almost 9 tons of residues are produced when 1 ton of aluminum oxide is produced, and the defects of high energy consumption, high cost and the like exist.
CN106542551B discloses a method for co-producing dawsonite and hydrated calcium silicate from fly ash according to CaO/SiO 2 Mixing quicklime, fly ash and water ingredients with the molar ratio of 0.3-1.5 and the liquid-solid ratio of 5 ml/g-50 ml/g, adding 5 g/L-100 g/L NaOH to adjust the pH value of the slurry, reacting for 0.5-12 h in a high-pressure closed container with the temperature of 120-260 ℃, and obtaining a dissolving solution mainly comprising sodium metaaluminate and a dissolving slag mainly comprising calcium silicate hydrate through solid-liquid separation; then introducing CO with the volume concentration of 10-100% into the dissolved solution 2 The gas, along with the reduction of the pH value of the solution, aluminum oxide is precipitated in the form of crystals, and when the pH value is 9.5-8.0, ventilation is finished; then the crystal mainly of dawsonite is obtained through solid-liquid separation operation. The method has low alumina extraction rate of only 45%.
Disclosure of Invention
The invention aims to solve the technical problems of overcoming the defects in the prior art and providing the method for co-producing the sodium silicate, tobermorite, boehmite and calcium carbonate by utilizing the fly ash, which has the advantages of low energy consumption, low cost, higher extraction rate of silicon and aluminum elements and high utilization rate.
The technical scheme adopted for solving the technical problems is that the method for co-producing the water glass, tobermorite, boehmite and calcium carbonate by utilizing the fly ash comprises the following steps:
a. preparation of Water glass
(a1) Mixing the fly ash with 10-30% sodium hydroxide solution, and controlling amorphous SiO in NaOH and fly ash 2 The molar ratio of (2) is 0.4-1.6:1, and the water-solid ratio of the reaction system is 1:1.0 to 5.0, carrying out hydrothermal reaction for 0.4 to 5.0 hours at the temperature of 95 to 180 ℃ under the reaction pressure of 0.2 to 1.0Mpa, and then carrying out solid-liquid separation to respectively obtain a low-modulus sodium silicate solution and desilication fly ash filter residues;
(a2) Uniformly mixing the low-modulus water glass solution obtained in the step (a 1), 10-30% sodium hydroxide solution and fly ash, and controlling amorphous SiO in NaOH and fly ash 2 The molar ratio of (2) is 0.4-1.0:1, and the water-solid ratio of the reaction system is controlled to be 1:1.0 to 5.0, carrying out hydrothermal reaction for 0.4 to 5.0 hours at the temperature of 95 to 180 ℃ under the reaction pressure of 0.2 to 1.0Mpa, and then carrying out solid-liquid separation to respectively obtain a high modulus water glass solution and desilication fly ash filter residues;
(a3) Adding a impurity removing agent and a filter aid into the high modulus water glass solution obtained in the step (a 2) to react, filtering, and collecting filtrate, namely water glass, wherein filter residues are desilication fly ash;
b. preparation of tobermorite and sodium metaaluminate solutions
(b1) Adding water, quicklime and sodium hydroxide solution with the concentration of 5-25 g/L (preferably 10-20 g/L) into the desilication fly ash filter residue obtained in the step (a 3), mixing, and controlling the water-solid ratio of a reaction system to be 5-20: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 The molar weight is 0.5 to 1.0 times, the hydrothermal reaction is carried out for 0.4 to 4.0 hours at 160 to 240 ℃ under the reaction pressure of 0.6 to 2.5Mpa, and then the solid-liquid separation is carried out, thus obtaining the crude sodium metaaluminate solution and the desilication fly ash for the first timeFiltering residues;
(b2) Adding water and sodium hydroxide solution with the concentration of 5-25 g/L (preferably 10-20 g/L) into the first dealuminated filter residue of the desilication fly ash obtained in the step (b 1), uniformly mixing, and controlling the water-solid ratio of the reaction system to be 5-20 again: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 Performing hydrothermal reaction for 0.4-4.0 h at 160-240 ℃ under the reaction pressure of 0.6-2.5 Mpa by 0.5-1.0 time of the molar weight, and performing solid-liquid separation to obtain sodium metaaluminate crude liquid and second dealuminized filter residues of desilication fly ash;
(b3) Mixing the desilication fly ash obtained in the step (b 2) with water, separating by a cyclone separator, overflowing to obtain tobermorite slurry, filtering the tobermorite slurry, and drying to obtain tobermorite;
c. preparation of boehmite and calcium carbonate
(c1) Mixing the crude sodium metaaluminate solution obtained in the steps (b 1) and (b 2), adding quicklime milk, carrying out desilication reaction, and carrying out solid-liquid separation to obtain a sodium metaaluminate desilication solution and filter residues;
(c2) Mixing the sodium metaaluminate desilication solution obtained in the step (c 1) with filter residues, then adding lime milk again for secondary desilication, then adding oxalic acid, and performing solid-liquid separation to obtain sodium metaaluminate desilication refined solution and filter residues containing calcium aluminate;
(c3) Returning the filter residue obtained in the step (c 2) to the step (b 1), mixing with the desilication fly ash filter residue obtained in the step (a 3), adding water, quicklime and sodium hydroxide solution, uniformly mixing, and carrying out hydrothermal reaction;
introducing CO into the desilication refined solution of the sodium metaaluminate obtained in the step (c 2) 2 Performing carbonization reaction on the gas at the temperature of 85-95 ℃, aging for 10-90 min (preferably 40-60 min) when the pH value of the reaction system is 8.0-10.5, and performing solid-liquid separation to obtain sodium carbonate solution and boehmite filter cake;
(c4) Adding lime milk into the sodium carbonate solution obtained in the step (c 3), carrying out causticization reaction, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain calcium carbonate; the obtained calcium carbonate is light calcium carbonate;
adding deionized water into the boehmite filter cake obtained in the step (c 3), soaking with a sodium removing agent, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain boehmite.
Further, in the step (a 1), the mass concentration of the sodium hydroxide solution is 15-20%, and the NaOH and the amorphous SiO in the fly ash are 2 The molar ratio of (2) is 0.6-1.0:1; the water-solid ratio is 1:1.2 to 3.0; the temperature of the hydrothermal reaction is 135-160 ℃, the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.
Further, in the step (a 2), the mass concentration of the sodium hydroxide solution is 15-20%, and the NaOH and the amorphous SiO in the fly ash are 2 The molar ratio of (2) is 0.6-1.0:1; the water-solid ratio is 1:1.2 to 3.0; the temperature of the hydrothermal reaction is 135-160 ℃, the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.
Further, in the step (a 3), the impurity removing agent is Na 2 S, S; the filter aid diatomite; the reaction temperature is 65-90 ℃, and the reaction time is 0.5-2.0 h.
Further, in the step (b 1) and the step (b 2), the water-to-solid ratio is 8 to 15:1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 0.7 to 0.8 times of the molar weight; the pressure of the reaction is 1.0-2.0 Mpa, the temperature of the reaction is 180-220 ℃, and the time of the reaction is 1.0-2.0 h.
In the step (b 3), the obtained tobermorite is further dried and sieved to obtain tobermorite powder; the underflow separated by the cyclone separator can be recycled and reused and is continuously used for extracting other metal elements such as Fe and the like.
Further, in the step (c 1), the lime milk is used in an amount of 1 to 5g per liter of sodium metaaluminate crude liquid; the temperature of the desilication reaction is 85-95 ℃; the desilication reaction time is 0.5-2 h.
Further, in the step (c 2), the lime milk is used in an amount of 1-5 g/liter of sodium metaaluminate desilication solution; the temperature of the second desilication reaction is 85-95 ℃; the second desilication reaction time is 0.5-1 h; the adding amount of oxalic acid is 1-5 g/L sodium metaaluminate desilication solution.
Further, in the step (c 2), the oxalic acid is used for precipitating calcium ions in the solution, and the precipitation time is 0.5-1 h.
Further, in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; the curing time is 30-60 min.
In the step (c 4), deionized water is added to the boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid with the concentration of 2-5% is added, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added for treatment.
Further, in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 hours, preferably 4-5 hours.
Water glass, tobermorite and boehmite are common substances containing aluminum or silicon extracted from fly ash. In the preparation process of the water glass, the main chemical reactions are as follows:
2NaOH+SiO 2 →Na 2 O·mSiO 2 +H 2 O，2NaOH+Al 2 O 3 →2NaAlO 2 +H 2 O，
the main chemical side reactions that occur are:
2NaAlO 2 +2Na 2 SiO 3 +4H 2 O→Na 2 O·Al 2 O 3 ·2SiO 2 ·2H 2 O↓+4NaOH。
in the preparation process of the tobermorite and sodium metaaluminate solution, the main chemical reactions are as follows:
3Al 2 O 3 ·2SiO 2 +CaO+NaOH→NaAlO 2 +Ca 5 Si 6 (OH) 18 ·5H 2 O，
SiO 2 +CaO+H 2 O→Ca 5 Si 6 (OH) 18 ·5H 2 O，
the main chemical side reactions that occur are:
2NaAlO 2 +2Na 2 SiO 3 +4H 2 O→Na 2 O·Al 2 O 3 ·2SiO 2 ·2H 2 O↓+4NaOH。
in the preparation of boehmite and calcium carbonate according to the invention, the main chemical reactions that occur are:
2NaAlO 2 +CO 2 +H 2 O→2AlOOH+Na 2 CO 3 ，2NaOH+CO 2 +H 2 O→Na 2 CO 3 +H 2 O
the main chemical side reactions that occur are:
Na 2 CO 3 +CO 2 +H 2 O→2NaHCO 3 。
the water glass is also called sodium silicate, is commonly called as water solution of water-soluble silicate, and is an ore binder. The chemical formula of the water glass is R 2 O·nSiO 2 Wherein R is 2 O is alkali metal oxide, n is the ratio of the mole number of silicon dioxide to the mole number of alkali metal oxide, and is called the modulus of water glass. The water glass has very wide application and almost extends to various fields of national economy. The water glass can be used for manufacturing various silicate products such as silica gel, white carbon black, zeolite molecular sieve, sodium metasilicate pentahydrate, silica sol, lamellar sodium silicate, instant powdery sodium silicate, potassium sodium silicate and the like, and is a basic raw material of silicon compounds.
Tobermorite is a hydrated calcium silicate mineral, is of a layered structure, has small density and light weight, contains adsorbed water and crystal water, and can be made into a microporous structure by adding fibers. The tobermorite has good heat insulation property and is mainly used for manufacturing heat insulation materials and adsorption materials. Tobermorite is widely applied to kiln, equipment and pipeline engineering in the industries of metallurgy, building materials, electric power, chemical industry and the like.
Pure boehmite is a white crystal with the formula gamma-AlOOH, but common boehmite often contains impurities and appears yellowish green or brownish red. When the temperature exceedsAt 400℃the boehmite is decomposed into gamma-Al 2 O 3 . Boehmite has the special properties of large specific surface area and porosity, good peptization property and dispersibility, high heat-resistant temperature, low hardness and the like, and is widely applied to the fields of flame retardance, surface coatings, catalysts and carriers, lithium battery diaphragms, ceramics, semiconductors and the like.
Compared with the prior art, the invention has the following beneficial effects:
(1) Researches show that by cooperatively controlling the concentration of reactants, the water-solid ratio and the pH value of the reaction liquid, the reaction temperature and the reaction time, the side reaction is basically eliminated, the problems of multiple side reactions and product impurities and the like caused by low-grade raw materials are solved, and the high-modulus sodium silicate, tobermorite type hydrated calcium silicate and boehmite with high crystal phase purity and special morphology are obtained;
(2) According to the invention, a cyclone separator is adopted to separate filter residues after multi-stage aluminum extraction, pure hydrated calcium silicate is separated by overflow, and the underflow further enriches Fe, mn and other metal elements in the fly ash, so that the possibility of further extracting other trace elements in the fly ash is provided;
(3) Compared with the method for directly using fly ash, quicklime and sodium hydroxide to carry out dynamic hydrothermal reaction, the method utilizes amorphous SiO in the fly ash 2 The high-modulus water glass is obtained by one-step reaction, the aluminum-silicon ratio in the fly ash is improved, meanwhile, the alumina extraction process is adopted by a multi-stage hydrothermal method, so that the extraction rate of alumina is greatly improved, and the extraction rate of alumina = boehmite is converted into the mole number of alumina/the mole number of alumina in the fly ash.
(4) The method for co-producing the water glass, the tobermorite, the boehmite and the calcium carbonate by using the fly ash has the advantages of low energy consumption, no generation of dissolved slag, low cost, higher extraction rate of silicon and aluminum elements and great improvement of the economic value and the social value of the fly ash.
Drawings
FIG. 1 is an XRD phase analysis of a sample of fly ash from a power plant used in the examples.
FIG. 2 is an SEM image of boehmite obtained in example 1.
Detailed Description
The invention will be further described with reference to the drawings and the specific examples.
The following examples used fly ash (from a power plant) and the main ingredients are shown in the following table:
component name Fly ash 2 #) Fly ash 4 #) Average of
CaO(wt％) 5.670 6.380 5.940
K 2 O(wt％) 1.050 1.600 1.240
Na 2 O(wt％) 0.380 0.560 0.438
Al 2 O 3 (wt％) 28.560 25.770 26.925
SiO 2 (wt％) 50.010 52.970 51.483
MgO(wt％) 0.560 0.750 0.625
TiO 2 (wt％) 1.870 1.830 1.815
Fe 2 O 3 (wt％) 7.870 6.020 7.728
P 2 O 5 (wt％) 0.250 0.310 0.238
SO 3 (wt％) 3.480 3.440 3.225
Others 0.320 0.39 0.350
Example 1
The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash comprises the following steps:
a. preparation of Water glass
(a1) 1000g of flyash No. 2 and 1000g of sodium hydroxide solution with the mass concentration of 20% are mixed, and the amorphous SiO in NaOH and flyash is controlled 2 The molar ratio of (2) is 0.774, the water-solid ratio of the reaction system is 0.67, the hydrothermal reaction is carried out for 2 hours at 135 ℃ under the reaction pressure of 0.3Mpa, then solid-liquid separation is carried out, 1315g of low modulus water glass solution with modulus of 2.4 and 689g of desilication fly ash filter residues are respectively obtained, and the desilication rate is 62.2%;
(a2) Mixing the low modulus water glass solution obtained in the step (a 1) with 1000g of fly ash 2# and controlling the water-solid ratio of a reaction system to be 0.46 again, carrying out hydrothermal reaction for 2 hours at 135 ℃ under the reaction pressure of 0.3Mpa, and then carrying out solid-liquid separation to respectively obtain 1525g of high modulus water glass solution with the modulus of 3.62 and 767g of desilication fly ash filter residues, wherein the desilication rate is 46.5%;
(a3) Adding 20g of impurity removing agent Na into the high-modulus water glass solution obtained in the step (a 2) 2 S and 50g of filter aid diatomite, standing and settling for 5 hours at 90 ℃, then filtering, and collecting 1500g of water glass filtrate with the modulus of 3.45, wherein the filter residue is 1456g of desilication fly ash;
b. preparation of tobermorite and sodium metaaluminate solutions
(b1) Adding 20000g of water, 340g of quicklime and 1400g of sodium hydroxide solution with the concentration of 20g/L into the desilication fly ash filter residue obtained in the step (a 3), mixing, controlling the water-solid ratio of a reaction system to be 9.47, wherein the total molar quantity of the added quicklime and CaO in the desilication fly ash is SiO in the desilication fly ash 2 Carrying out hydrothermal reaction for 2 hours at 180 ℃ under the reaction pressure of 1.0Mpa and 0.8 times of the molar weight, and then carrying out solid-liquid separation to obtain 16665g of sodium metaaluminate crude liquid and 6531g of desilication fly ash first-time dealumination filter residue;
(b2) 15500g of water and 1400g of sodium hydroxide with the concentration of 20g/L are added into the first dealumination filter residue of the desilication fly ash obtained in the step (b 1)Mixing the solutions, controlling the water-solid ratio of the reaction system to be 9.47 again, wherein the total molar quantity of the added quicklime and CaO in the desilication fly ash is SiO in the desilication fly ash 2 Carrying out hydrothermal reaction for 2h at 180 ℃ under the reaction pressure of 1.0Mpa and the molar weight of 0.7 times, and carrying out solid-liquid separation to obtain 16071g of sodium metaaluminate crude liquid and 7360g of desilication fly ash second dealumination filter residue;
(b3) Mixing the desilication fly ash obtained in the step (b 2) with water according to a mass ratio of 1:5, separating by a cyclone separator, overflowing to obtain tobermorite slurry, filtering the tobermorite slurry, and drying to obtain 1083g tobermorite powder; 284g of powder is obtained in the underflow after separation by a cyclone separator, wherein Fe 2 O 3 The content is 55.3%;
c. preparation of boehmite and calcium carbonate
(c1) Mixing the crude sodium metaaluminate solution obtained in the step (b 1) and the step (b 2), keeping the system temperature at 85-95 ℃, adding 20g of quicklime milk, carrying out desilication reaction for 1h, and carrying out solid-liquid separation to obtain 32562g of sodium metaaluminate desilication solution and 174g of filter residues;
(c2) Mixing the sodium metaaluminate desilication solution obtained in the step (c 1) with filter residues, keeping the system temperature at 85-95 ℃, then adding 20g of lime milk again, carrying out secondary desilication, reacting for 1h, then adding 10g of oxalic acid, reacting for 0.5h, and carrying out solid-liquid separation to obtain 32517g of sodium metaaluminate desilication refined solution and 219g of filter residues containing calcium metasilicate;
(c3) Returning the filter residue obtained in the step (c 2) to the step (b 1), mixing with the desilication fly ash filter residue obtained in the step (a 3), adding water, quicklime and sodium hydroxide solution, uniformly mixing, and carrying out hydrothermal reaction;
introducing 40-80% CO by volume into the sodium metaaluminate desilication refined solution (the temperature is 85-95 ℃) obtained in the step (c 2) 2 Performing carbonization reaction at a flow rate of 2L/min, aging for 60min when the pH value of the reaction system is 8.8, and performing solid-liquid separation to obtain 31027g of sodium carbonate solution and 1490g of boehmite filter cake;
(c4) Adding 514g of lime milk into the sodium carbonate solution obtained in the step (c 3), carrying out causticization reaction for 1h, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain 813g of light calcium carbonate;
adding deionized water into the boehmite filter cake obtained in the step (c 3), regulating the pH value to 7 by using dilute hydrochloric acid, adding 50g of sodium removing agent ammonium bicarbonate, preserving heat and soaking for 5 hours, then carrying out solid-liquid separation, collecting solid, washing and drying the solid to obtain 447g of boehmite.
Through statistical analysis, the main material consumption of the embodiment is respectively as follows: 2000g of fly ash, 836g of quicklime, 358g of carbon dioxide gas, 190g of sodium hydroxide (most of which are recovered) and washing water can be recycled. The quality of the product obtained in this example is: 1500g of high modulus water glass, 1083g of tobermorite powder, 447g of boehmite and 813g of light calcium carbonate powder. The extraction yield of the alumina of this example was 66.5%. SEM images of boehmite obtained in this example are shown in fig. 2.
Example 2
The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash comprises the following steps:
a. preparation of Water glass
(a1) 1000g of flyash 4# and 1000g of sodium hydroxide solution with mass concentration of 30% and 300g of water are mixed, and amorphous SiO in NaOH and flyash is controlled 2 The molar ratio of (2) is 1.48, the water-solid ratio of the reaction system is 0.653, the hydrothermal reaction is carried out for 1h at 160 ℃ under the reaction pressure of 0.6Mpa, then solid-liquid separation is carried out, 1363g of low modulus water glass solution with modulus of 2.6 and 590g of desilication fly ash filter residue are respectively obtained, and the desilication rate is 77.4%;
(a2) Mixing the low modulus water glass solution obtained in the step (a 1) with 1000g of fly ash 4# and controlling the water-solid ratio of a reaction system to be 0.44, carrying out hydrothermal reaction for 1h at 160 ℃ under the reaction pressure of 0.6Mpa, and then carrying out solid-liquid separation to respectively obtain 1599g of high modulus water glass solution with the modulus of 4.1 and 763g of desilication fly ash filter residues, wherein the desilication rate is 44.7%;
(a3) Adding 20g of impurity removing agent Na into the high-modulus water glass solution obtained in the step (a 2) 2 S and 50g of filter aid diatomite, standing and settling for 5 hours at 90 ℃, then filtering, collecting 1550gWater glass filtrate with the modulus of 3.5 and filter residue of 1353g desilication fly ash;
b. preparation of tobermorite and sodium metaaluminate solutions
(b1) Adding 20000g of water, 270g of quicklime and 1200g of sodium hydroxide solution with the concentration of 20g/L into the desilication fly ash filter residue obtained in the step (a 3), mixing, controlling the water-solid ratio of a reaction system to be 10.5, wherein the total molar quantity of the added quicklime and CaO in the desilication fly ash is SiO in the desilication fly ash 2 Carrying out hydrothermal reaction for 1h at 200 ℃ under the reaction pressure of 1.55Mpa and 0.7 time of the molar weight, and then carrying out solid-liquid separation to obtain 5923g of sodium metaaluminate crude liquid and 16700g of desilication fly ash first-time dealumination filter residue;
(b2) Adding 16100g of water and 1200g of sodium hydroxide solution with the concentration of 20g/L into the first dealuminated filter residue of the desilication fly ash obtained in the step (b 1), mixing, and controlling the water-solid ratio of the reaction system to be 10.5 again, wherein the total molar quantity of the added quicklime and CaO in the desilication fly ash is SiO in the desilication fly ash 2 Carrying out hydrothermal reaction for 2h at 180 ℃ under the reaction pressure of 1.0Mpa and the molar weight of 0.7 times, and carrying out solid-liquid separation to obtain 16776g of sodium metaaluminate crude liquid and 6457g of desilication fly ash second dealumination filter residue;
(b3) Mixing the desilication fly ash obtained in the step (b 2) with water according to a mass ratio of 1:5, separating by a cyclone separator, overflowing to obtain tobermorite slurry, filtering the tobermorite slurry, and drying to obtain 859g tobermorite powder; 357g of powder is obtained in the underflow after separation by a cyclone separator, wherein Fe 2 O 3 The content is 33.6%;
c. preparation of boehmite and calcium carbonate
(c1) Mixing the crude sodium metaaluminate solution obtained in the step (b 1) and the step (b 2), keeping the system temperature at 85-95 ℃, adding 20g of quicklime milk, carrying out desilication reaction for 1h, and carrying out solid-liquid separation to obtain 33492g of sodium metaaluminate desilication solution and 174g of filter residues;
(c2) Mixing the sodium metaaluminate desilication solution obtained in the step (c 1) with filter residues, keeping the system temperature at 85-95 ℃, then adding 20g of lime milk again, carrying out secondary desilication, reacting for 1h, then adding 10g of oxalic acid, reacting for 0.5h, and carrying out solid-liquid separation to obtain 3347g of sodium metaaluminate desilication refined solution and 219g of calcium aluminate filter residues;
(c3) Returning the filter residue obtained in the step (c 2) to the step (b 1), mixing with the desilication fly ash filter residue obtained in the step (a 3), adding water, quicklime and sodium hydroxide solution, uniformly mixing, and carrying out hydrothermal reaction;
introducing 40-80% CO by volume into the sodium metaaluminate desilication refined solution (the temperature is 85-95 ℃) obtained in the step (c 2) 2 Performing carbonization reaction at a flow rate of 2L/min, aging for 60min when the pH value of the reaction system is 8.8, and performing solid-liquid separation to obtain 32045g of sodium carbonate solution and 1403g of boehmite filter cake;
(c4) Adding 469g of lime milk into the sodium carbonate solution obtained in the step (c 3), carrying out causticization reaction for 1h, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain 837g of light calcium carbonate;
adding deionized water into the boehmite filter cake obtained in the step (c 3), regulating the pH value to 7.5 by using dilute hydrochloric acid, adding 45g of sodium removing agent ammonium bicarbonate, preserving heat and soaking for 5 hours, then carrying out solid-liquid separation, collecting solid, washing and drying the solid, thus obtaining 421g of boehmite.
Through statistical analysis, the main material consumption of the embodiment is respectively as follows: 2000g of fly ash, 778g of quicklime, 368g of carbon dioxide gas, 51g of sodium hydroxide (most of which is recovered) and the washing water can be recycled. The quality of the product obtained in this example is: 1550g of high-modulus water glass, 829g of tobermorite powder, 421g of boehmite and 837g of light calcium carbonate powder. The extraction yield of the alumina of this example was 69.38%.

Claims (30)

1. The method for co-producing the water glass, tobermorite, boehmite and calcium carbonate by utilizing the fly ash is characterized by comprising the following steps of:
a. preparation of Water glass
(a1) Mixing the fly ash with 10-30% sodium hydroxide solution, and controlling amorphous SiO in NaOH and fly ash 2 The molar ratio of the water to the reaction system is 0.4-1.6:1The solid ratio is 1: 1.0-5.0, carrying out hydrothermal reaction for 0.4-5.0 h at 95-180 ℃ under the reaction pressure of 0.2-1.0 mpa, and then carrying out solid-liquid separation to respectively obtain a low-modulus sodium silicate solution and desilication fly ash filter residues;
(a2) Uniformly mixing the low-modulus water glass solution obtained in the step (a 1), 10-30% sodium hydroxide solution and fly ash, and controlling amorphous SiO in NaOH and fly ash 2 The molar ratio of (2) is 0.4-1.0:1, and the water-solid ratio of the reaction system is controlled to be 1: 1.0-5.0, carrying out hydrothermal reaction for 0.4-5.0 h at 95-180 ℃ under the reaction pressure of 0.2-1.0 mpa, and then carrying out solid-liquid separation to respectively obtain a high-modulus water glass solution and desilication fly ash filter residues;
(a3) Adding a impurity removing agent and a filter aid into the high modulus water glass solution obtained in the step (a 2) to react, filtering, and collecting filtrate, namely water glass, wherein filter residues are desilication fly ash;
b. preparation of tobermorite and sodium metaaluminate solutions
(b1) Adding water, quicklime and 5-25 g/L sodium hydroxide solution into the desilication fly ash filter residue obtained in the step (a 3), mixing, and controlling the water-solid ratio of a reaction system to be 5-20: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 Performing hydrothermal reaction for 0.4-4.0 h at 160-240 ℃ under the reaction pressure of 0.6-2.5 mpa by 0.5-1.0 time of the molar weight, and then performing solid-liquid separation to obtain sodium metaaluminate crude liquid and desilication fly ash first-time dealumination filter residues;
(b2) Adding water and sodium hydroxide solution with the concentration of 5-25 g/L into the first dealumination filter residue of the desilication fly ash obtained in the step (b 1), uniformly mixing, and controlling the water-solid ratio of the reaction system to be 5-20 again: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 Performing hydrothermal reaction for 0.4-4.0 h at 160-240 ℃ under the reaction pressure of 0.6-2.5 mpa by 0.5-1.0 time of the molar weight, and performing solid-liquid separation to obtain sodium metaaluminate crude liquid and desilication fly ash secondary dealumination filter residues;
(b3) Mixing the desilication fly ash obtained in the step (b 2) with water, separating by a cyclone separator, overflowing to obtain tobermorite slurry, filtering the tobermorite slurry, and drying to obtain tobermorite;
c. preparation of boehmite and calcium carbonate
(c1) Mixing the crude sodium metaaluminate solution obtained in the steps (b 1) and (b 2), adding quicklime milk, carrying out desilication reaction, and carrying out solid-liquid separation to obtain a sodium metaaluminate desilication solution and filter residues;
(c2) Mixing the sodium metaaluminate desilication solution obtained in the step (c 1) with filter residues, then adding lime milk again for secondary desilication, then adding oxalic acid, and performing solid-liquid separation to obtain sodium metaaluminate desilication refined solution and filter residues containing calcium aluminate;
(c3) Returning the filter residue obtained in the step (c 2) to the step (b 1), mixing with the desilication fly ash filter residue obtained in the step (a 3), adding water, quicklime and sodium hydroxide solution, uniformly mixing, and carrying out hydrothermal reaction;
introducing CO into the desilication refined solution of the sodium metaaluminate obtained in the step (c 2) 2 Performing carbonization reaction on the gas at the temperature of 85-95 ℃, aging for 10-90 min when the pH value of the reaction system is 8.0-10.5, and performing solid-liquid separation to obtain sodium carbonate solution and boehmite filter cakes;
(c4) Adding lime milk into the sodium carbonate solution obtained in the step (c 3), carrying out causticization reaction, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain calcium carbonate;
adding deionized water into the boehmite filter cake obtained in the step (c 3), soaking with a sodium removing agent, then carrying out solid-liquid separation, collecting solids, washing the solids, and drying to obtain boehmite.
2. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 1, wherein in the step (a 1), the mass concentration of the sodium hydroxide solution is 15-20%; amorphous SiO in NaOH and fly ash 2 The molar ratio of (2) is 0.6-1.0:1; the water-solid ratio is 1: 1.2-3.0; the temperature of the hydrothermal reaction is 135-160 ℃,the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.
3. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 1 or 2, wherein in the step (a 2), the mass concentration of the sodium hydroxide solution is 15-20%; amorphous SiO in NaOH and fly ash 2 The molar ratio of (2) is 0.6-1.0:1; the water-solid ratio is 1: 1.2-3.0; the temperature of the hydrothermal reaction is 135-160 ℃, the reaction pressure is 0.3-0.5 MPa, and the reaction time is 1-2 h.
4. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 1 or 2, wherein in step (a 3), the impurity removing agent is Na 2 S, S; the filter aid is diatomite; the reaction temperature is 65-90 ℃, and the reaction time is 0.5-2.0 h.
5. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 3, wherein in step (a 3), the impurity removing agent is Na 2 S, S; the filter aid is diatomite; the reaction temperature is 65-90 ℃, and the reaction time is 0.5-2.0 h.
6. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 1 or 2, wherein in the step (b 1) and the step (b 2), the water-solid ratio is 8-15: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 0.7 to 0.8 times of the molar weight; the pressure of the reaction is 1.0-2.0 mpa, the reaction temperature is 180-220 ℃, and the reaction time is 1.0-2.0 h.
7. The method for co-production of water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 3, wherein the steps (b 1) and (b 1)(b2) Wherein the water-solid ratio is 8-15: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 0.7 to 0.8 times of the molar weight; the pressure of the reaction is 1.0-2.0 mpa, the reaction temperature is 180-220 ℃, and the reaction time is 1.0-2.0 h.
8. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 4, wherein in the step (b 1) and the step (b 2), the water-solid ratio is 8-15: 1, the total mol weight of CaO in the added quicklime and the desilication fly ash is SiO in the desilication fly ash 2 0.7 to 0.8 times of the molar weight; the pressure of the reaction is 1.0-2.0 mpa, the reaction temperature is 180-220 ℃, and the reaction time is 1.0-2.0 h.
9. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 1 or 2, wherein in the step (c 2), the dosage of the lime milk is 1-5 g/liter of sodium metaaluminate desilication solution; the temperature of the second desilication reaction is 85-95 ℃; the second desilication reaction time is 0.5-1 h; the adding amount of oxalic acid is 1-5 g/L sodium metaaluminate desilication solution.
10. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 3, wherein in the step (c 2), the amount of lime milk is 1-5 g/liter of sodium metaaluminate desilication solution; the temperature of the second desilication reaction is 85-95 ℃; the second desilication reaction time is 0.5-1 h; the adding amount of oxalic acid is 1-5 g/L sodium metaaluminate desilication solution.
11. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 4, wherein in the step (c 2), the dosage of the lime milk is 1-5 g/liter of sodium metaaluminate desilication solution; the temperature of the second desilication reaction is 85-95 ℃; the second desilication reaction time is 0.5-1 h; the adding amount of oxalic acid is 1-5 g/L sodium metaaluminate desilication solution.
12. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 6, wherein in the step (c 2), the dosage of the lime milk is 1-5 g/liter of sodium metaaluminate desilication solution; the temperature of the second desilication reaction is 85-95 ℃; the second desilication reaction time is 0.5-1 h; the adding amount of oxalic acid is 1-5 g/L sodium metaaluminate desilication solution.
13. The method for CO-production of water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 1 or 2, wherein in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; aging time is 30-60 min.
14. The method for CO-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 3, wherein in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; aging time is 30-60 min.
15. The method for CO-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 4, wherein in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; aging time is 30-60 min.
16. The method for co-production of water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 6, wherein,in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; aging time is 30-60 min.
17. The method for CO-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 9, wherein in step (c 3), the CO 2 The volume percentage of the gas is 50-100%, and the CO is 2 The flow rate of the gas is 0.5L/min-20L/min; the pH value is 8.8-9.0; aging time is 30-60 min.
18. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 1 or 2, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
19. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 3, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
20. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 4, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
21. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 6, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
22. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 9, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
23. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by utilizing fly ash according to claim 13, wherein in the step (c 4), deionized water is added into a boehmite filter cake obtained in the step (c 3), dilute hydrochloric acid is added into the filter cake, the pH value of the mixed solution is adjusted to 6-8, and then a sodium removing agent is added into the mixed solution for treatment.
24. The method for co-production of water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 1 or 2, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
25. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash according to claim 3, wherein in the step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
26. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 4, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
27. The method for co-producing water glass, tobermorite, boehmite and calcium carbonate using fly ash according to claim 6, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
28. The method for co-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 9, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
29. The method for co-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 13, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
30. The method for co-production of water glass, tobermorite, boehmite, and calcium carbonate using fly ash according to claim 18, wherein in step (c 4), the sodium removing agent is an organic ammonium salt or an inorganic ammonium salt; the soaking temperature is 60-90 ℃; the soaking time is 1-10 h.
CN202110645309.6A 2021-06-09 2021-06-09 Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash Active CN113213499B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110645309.6A CN113213499B (en) 2021-06-09 2021-06-09 Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110645309.6A CN113213499B (en) 2021-06-09 2021-06-09 Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash

Publications (2)

Publication Number Publication Date
CN113213499A CN113213499A (en) 2021-08-06
CN113213499B true CN113213499B (en) 2024-01-26

Family

ID=77083443

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110645309.6A Active CN113213499B (en) 2021-06-09 2021-06-09 Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash

Country Status (1)

Country Link
CN (1) CN113213499B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101284668A (en) * 2007-04-12 2008-10-15 清华大学 Process for abstracting earth silicon, oxide of alumina and gallium oxide from high-alumina flying ash
CN103303952A (en) * 2012-03-06 2013-09-18 中国科学院过程工程研究所 Method for linked preparation of sodium aluminate and production of silica-based material by means of high-alumina fly ash low-temperature liquid-phase alkali dissolving
CN106542551A (en) * 2016-11-24 2017-03-29 中南大学 A kind of method of coproduction dawsonite and hydrated calcium silicate from flyash

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101284668A (en) * 2007-04-12 2008-10-15 清华大学 Process for abstracting earth silicon, oxide of alumina and gallium oxide from high-alumina flying ash
CN103303952A (en) * 2012-03-06 2013-09-18 中国科学院过程工程研究所 Method for linked preparation of sodium aluminate and production of silica-based material by means of high-alumina fly ash low-temperature liquid-phase alkali dissolving
CN106542551A (en) * 2016-11-24 2017-03-29 中南大学 A kind of method of coproduction dawsonite and hydrated calcium silicate from flyash

Also Published As

Publication number Publication date
CN113213499A (en) 2021-08-06

Similar Documents

Publication Publication Date Title
CN100542961C (en) A kind of technology of processing bauxite to produce hydroted alumina with sodium hydroxide molten salt growth method
US7871583B2 (en) Process for recovery of silica followed by alumina from coal fly ash
CN109516484B (en) Method for producing alumina by sintering carbide slurry fly ash and coal gangue
CN102583477B (en) Comprehensive utilization method of high-ferrum and low-grade bauxite
WO2012151767A1 (en) Method for preparing alumina from high alumina fly ash and co-producing active calcium silicate
CN106542551B (en) A kind of method of coproduction dawsonite and hydrated calcium silicate from flyash
WO2018233688A1 (en) Method for preparing aluminum hydroxide by treating medium- and low-grade bauxite by using one-step alkali heat process of andradite
WO2013143335A1 (en) Method for extracting aluminium oxide in fly ash by alkaline process
CN102838147B (en) Method for preparing mixed solution of sodium aluminate and potassium aluminate from alkaline syenite
CN102502733A (en) Method for treating gibbsite by using high-concentration alkali liquor under normal pressure
CN108892146B (en) Desiliconization method of silicon-aluminum-containing material
CN103121700A (en) Method for preparing ultrafine alumina and coproducing and white carbon black by utilizing coal series kaolin
CN103130254A (en) Method for producing aluminum oxide by using alkaline method
CN101746795A (en) Method for producing alumina from bauxite
CN1766128A (en) Iron and alumnium extraction method from high iron bauxite
CN108658092B (en) Method for preparing P-type molecular sieve and high-silicon mordenite from aluminum residue extracted by fly ash acid method and utilization method of fly ash
CN103421960A (en) Method for efficiently recycling ferro-aluminium from bauxite tailings and synchronously preparing high siliceous residues
CN104445310A (en) Novel process for treating middle-low bauxite in complete wet method alkali system
CN100363262C (en) Method for producing alumina
CN113213499B (en) Method for co-producing water glass, tobermorite, boehmite and calcium carbonate by using fly ash
WO2019019844A1 (en) Process for producing 4a zeolite by treating bayer process red mud with andradite one-step alkali heat method
CN100593018C (en) Technological process method of producing aluminium oxide using high aluminium slag
CN103771471B (en) Method for preparing aluminum oxide through coal ash
CN115072749B (en) Method for extracting lithium from spodumene without slag
CN111268686A (en) Method for preparing water glass from silicate minerals and water glass

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
GR01 Patent grant
GR01 Patent grant