CN109847768B

CN109847768B - Comprehensive utilization method of titanium slag

Info

Publication number: CN109847768B
Application number: CN201910140636.9A
Authority: CN
Inventors: 李杨; 陈旭芳; 张岩昊; 陈昌; 王宝; 张华�; 倪红卫; 周建安
Original assignee: Wuhan University of Science and Engineering WUSE
Current assignee: Wuhan University of Science and Engineering WUSE
Priority date: 2019-02-26
Filing date: 2019-02-26
Publication date: 2021-10-12
Anticipated expiration: 2039-02-26
Also published as: CN109847768A

Abstract

The invention discloses a comprehensive utilization method of titanium slag, which mainly uses titanium slag containing TiO₂Using 49-51% titanium-containing electric furnace molten slag as basic raw material, removing Al and Si by alkali fusion and water immersion treatment, then making metal compound in the filter slag be completely converted into metal ion by acidolysis, and utilizing Ti⁴⁺The characteristic of easy hydrolysis under heating condition, and Ti is obtained by regulating and controlling the temperature⁴⁺Hydrolyzing to form nano TiO₂(ii) a Then Mg in the solution is caused to react through coprecipitation²⁺、Fe³⁺And Ca²⁺Precipitating to obtain Mg_2‑xCa_xA FeCl-type layered double hydroxide; then adopting solid phase mixing method to realize nano TiO₂Effective compounding with LDH to prepare TiO₂/Mg_2‑xCa_xThe FeCl composite material does not need high temperature and high pressure, has simple process and low cost, and the process condition is easy to control and no secondary pollutant is generated.

Description

Comprehensive utilization method of titanium slag

Technical Field

The invention belongs to the field of comprehensive utilization of metallurgical resources and material preparation, and particularly relates to a comprehensive utilization method of titanium slag, which is used for preparing nano TiO by utilizing melting slag of a titanium-containing electric furnace₂/Mg_2-xCa_xA method of FeCl composite material.

Background

TiO₂As a catalyst material, can completely degrade organic matters in sewage into CO under the condition of illumination₂And H₂O, has the advantages of high catalytic activity, strong oxidizing power, long service life, good chemical stability and the like, so that the TiO₂Is the best semiconductor photocatalyst for the currently accepted photocatalytic reaction; but TiO 2₂The following problems exist during the use: (1) TiO 2₂Is a wide bandgap semiconductor (E)_g3.2eV), which is responsive only to ultraviolet rays of short wavelength; (2) TiO 2₂The adsorption capacity of the catalyst is poor, and the photoproduction electron-hole pairs are easy to recombine, so that the catalytic activity of the catalyst is reduced; (3) TiO 2₂Suspension is formed with sewage in the process of catalytic degradation of sewage, so that the recycling efficiency is low, the use cost is increased, and the large-scale application of the suspension is limited; if the raw materials with low price can be adopted to prepare TiO₂Photocatalyst, and mixing TiO₂Loaded on materials with special properties, not only can reduce TiO₂The production cost is increased, the recycling efficiency is improved, and the special performance of the carrier can be utilized to improve TiO₂Adsorption of (3), inhibiting TiO₂The photo-generated electron-hole pair is compounded, and the synergistic effect among the components of the composite material is utilized to achieve the purpose of advantage complementation, so that the photocatalytic activity of the composite material is further improved.

LDH is a layered compound with a two-dimensional template structure, which is typically represented by the general chemical formula: [ M ] A_1x ²⁺M_x ³⁺(OH)₂][A^n-]_x/n·yH₂O, hydrotalcite has properties such as wide chemical components, variable layer charge density, ion exchange performance, reaction interlayer space, memory effect, flame retardant performance, rheology, colloid performance and the like, has strong adsorption performance, but has low separation efficiency, and limits wide application in fields such as catalysis, adsorption, nano composite materials and the like; if LDH is used as TiO₂A support for a photocatalyst, TiO₂The powder is effectively loaded in the LDH structure, the electric difference between LDH layers can be utilized to inhibit the recombination of photo-generated electron-hole pairs and improve TiO₂The photocatalytic activity of the composite can also utilize the controllability and the exchangeability of LDH interlayer ions to adsorb various inorganic ions and charged organic matters in sewage to improve TiO₂Further improve the adsorption performance of TiO₂The photodegradation capability of the photocatalyst on organic matters; thus, realize the nano TiO₂Effectively compound with LDH, can fully exert TiO₂The photocatalyst and the LDH adsorbing material have a synergistic effect, so that the comprehensive treatment capacity of the composite material on organic and inorganic pollutants in sewage is improved; in addition, the nano TiO can be effectively recovered by LDH₂Can be repeatedly used, and the use cost is reduced.

Another concern is that the titanium resource in China is very abundant, but the titanium resource is mostly in the form of low-grade vanadium titano-magnetite; for a long time, vanadium-titanium magnetite only utilizes iron and vanadium resources in the vanadium-titanium magnetite to generate a large amount of titanium-containing slag to be accumulated like a mountain, a better way for treatment is not found at present, particularly, research is carried out on titanium-containing electric furnace molten slag obtained by electric furnace molten separation after direct reduction, the titanium-containing electric furnace molten slag is directly accumulated in open air, not only a large amount of land is occupied, but also serious pollution is caused, and how to comprehensively utilize the titanium-containing electric furnace molten slag is always a concern of metallurgy and environmental workers.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a comprehensive utilization method of titanium slag, which is used for preparing nano TiO by utilizing melting slag of a titanium-containing electric furnace₂/Mg_2-xCa_xMethod for producing FeCl composite material by utilizing its componentsTi in molten slag of titanium electric furnace⁴⁺、Mg²⁺、Fe³⁺And Ca²⁺The active ingredients are equal, and the nano TiO is synthesized₂And Mg_2-xCa_xFeCl LDH with Mg_2-xCa_xFeCl LDH as TiO₂A support for a photocatalyst, TiO₂The powder is effectively loaded into an LDH structure to realize the nano TiO₂Effectively compounds with LDH, and realizes the comprehensive utilization of titanium slag.

In order to achieve the purpose, the invention adopts the technical scheme that:

a comprehensive utilization method of titanium slag comprises the following steps:

(1) mixing the titanium-containing electric furnace molten slag with solid sodium hydroxide, and carrying out alkali fusion roasting;

(2) levigating the roasted sample, performing stirring water leaching operation, and performing solid-liquid separation after stirring to obtain water leaching residue;

(3) mixing the water leaching residue and hydrochloric acid, stirring, performing acid leaching, and performing solid-liquid separation to obtain the product mainly containing Mg²⁺、Fe³⁺And Ca²⁺The metal salt filtrate and the filter residue;

(4) drying and grinding the filter residue, and calcining to prepare nano titanium dioxide;

(5) detecting Mg in the filtrate²⁺、Fe³⁺And Ca²⁺Is supplemented with MgCl₂，FeCl₃And CaCl₂Making Mg/Ca in the mixed system 1: 3-3: 1, [ Ca + Mg [ ]]Adjusting the pH value of the solution to 2:1, crystallizing the mixed solution at constant temperature, centrifuging and drying to obtain Mg_2-xCa_xA FeCl-type layered double hydroxide;

(6) TiO prepared in the step (4)₂With the Mg obtained in step (5)_2-xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1: 1-10, is uniformly mixed, and is ground and calcined to prepare TiO₂/Mg_2-xCa_xA FeCl composite material.

Preferably, the mass ratio of the molten slag powder of the titanium-containing electric furnace to the solid sodium hydroxide in the step (1) is 1: 1-1.5.

Preferably, the roasting condition in the step (1) is 500-700 ℃ for 1-3 h.

Preferably, the powder ground in the step (2) is more than 100 meshes, and the solid-liquid mass ratio is 1:10 to 100.

Preferably, the concentration of the hydrochloric acid in the step (3) is 0.3-1.5 mol/L, and the liquid-solid mass ratio is 30-60: 1, stirring for 4-8 h at the leaching temperature of 40-60 ℃.

Preferably, the calcination condition in the step (4) is 450 ℃ for 1 h.

Preferably, in the step (5), the crystallization is carried out at a constant temperature of 60-80 ℃ for 4-8 hours.

Preferably, the pH of the solution is adjusted in step (5) to a pH using NaOH solution or NH 3. H₂And adjusting the pH value to 9.0-11 by using O.

Preferably, the grinding speed in the step (6) is 300-500 rpm, and the grinding time is 2-4 h.

Preferably, the calcination condition in the step (6) is 300 ℃ for 1-3 h.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention takes the molten slag of a titanium-containing electric furnace as a raw material, removes Al and Si by alkali fusion and water immersion treatment, then completely converts metal compounds in the filter residue into metal ions by acidolysis, and then utilizes ICP-AES to test Ti in the solution⁴⁺、Mg² ⁺、Fe³⁺And Ca²⁺Concentration of metal ions, using Ti⁴⁺The characteristic of easy hydrolysis under heating condition, and Ti is obtained by regulating and controlling different temperatures⁴⁺Hydrolyzing to form nano TiO₂。

(2) With addition of MgCl₂，FeCl₃And CaCl₂The method regulates and controls the proportion of ions with different valence states, so that Mg/Ca is 1: 3-3: 1, [ Ca + Mg ]]2:1 of Fe, then using NaOH solution or NH with certain concentration₃·H₂Adjusting pH value with O, stirring to obtain Mg in the solution²⁺、Fe³⁺And Ca²⁺Coprecipitation is carried out to separate out, crystallization reaction is carried out for a period of time under the condition of certain temperature, suspension is centrifugally separated after complete reaction, and Mg is obtained after obtained precipitate is dried_2-xCa_xFeCl-type Layered Double Hydroxide (LDH).

(3) Adopting a solid phase mixing method to hydrolyze and separate out hydrated TiO₂Uniformly mixing with LDH prepared by coprecipitation in ethanol according to a certain proportion, grinding until the ethanol is completely evaporated, and controlling the grinding rate and grinding time to hydrate TiO₂The water molecules in the LDH are inserted into the interlayer gaps of the LDH, and the memory effect of the LDH layered structure and the controllability of the interlayer structure are utilized to realize TiO₂Effective load among LDH laminated structures, and finally removing hydrated TiO through calcination₂The bound water in (1) can be used for preparing TiO₂a/LDH composite material.

(4) The invention has simple process flow and less equipment investment; the main raw materials have wide sources and low price; synthesizing TiO by using molten slag of titanium-containing electric furnace as raw material₂the/LDH composite material can simultaneously solve the difficult problems of stacking of the titaniferous electric furnace molten slag and environmental hazard; the obtained product TiO₂the/LDH composite material can be used as a catalyst and a catalyst carrier in the fields of chemistry and chemical engineering; in the field of functional materials, as infrared and ultraviolet absorbing and blocking materials; in the plastic industry, can be used as an antibacterial additive, a flame retardant and a PVC stabilizer; in the field of environmental protection, the compounds have strong adsorption effect on a plurality of toxic and harmful ions, so the compounds can be used for water quality purification, sewage treatment, pollution prevention and environmental remediation and have wide application prospect.

Drawings

FIG. 1 is a process flow diagram of the present invention.

FIG. 2 is an XRD pattern of nano titanium dioxide obtained from a titaniferous electric furnace molten slag of example 1.

FIG. 3 (a) and (b) are SEM images of nano titania obtained from a titanium-containing electric furnace slag in example 1.

FIG. 4 shows Mg obtained from the slag of a titaniferous electric furnace in example 1_2-xCa_xXRD pattern of layered double hydroxide of FeCl.

FIG. 5 shows Mg obtained from the slag of a titaniferous electric furnace in example 1_2-xCa_xSEM image of layered double hydroxide of FeCl type.

FIG. 6(a) and (b) show melting from a titanium-containing electric furnace in example 1TiO obtained from slag separation₂/Mg_2-xCa_xAnd the absorbance change graph and the photodegradation efficiency change graph of the FeCl composite material to the rhodamine B solution.

FIG. 7 shows TiO samples obtained from slag of a titaniferous electric furnace in example 1₂/Mg_2-xCa_xGraph showing the change of the adsorption efficiency of FeCl composite material to sodium Triphosphate (TPP).

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, the present invention is further described in detail with reference to the following embodiments; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

The invention provides a method for preparing TiO₂/Mg_2-xCa_xThe method of FeCl composite material is to use the slag of titanium-containing electric furnace as metal element Ti⁴⁺、Mg²⁺、Fe³⁺And Ca²⁺Through chemical reaction, crystallization and calcining treatment to synthesize TiO₂/Mg_2- _xCa_xA FeCl composite material; the titanium-containing electric furnace molten slag has loose structure and strong chemical activity, wherein metal elements such as Al, Si and the like are easily dissolved and removed by strong alkali such as sodium hydroxide and the like, the purpose of alkali fusion calcination is to convert divalent and trivalent element oxides (hydroxides) in the mixture into solid solution, the calcined product is a bimetallic oxide, and the product can be directly put on the market as a product and can also be used for further synthesizing nano TiO₂And hydrotalcite as a raw material.

During the water immersion and stirring process, the water adding amount can be adjusted, so that the stirred product is a viscous and flowable suspension liquid; the water consumption is too low, and the raw materials are difficult to stir uniformly; the water consumption is too high, so that the energy consumption of the subsequent process and the equipment abrasion are greatly increased; the solid-liquid mass ratio of the slag to the water is preferably 1:10 to 100.

The ratio of divalent metal elements to trivalent metal elements in the raw materials has a certain influence on the properties of the final product, generally speakingWhen the dosage of the former is higher, the crystal structure of the product is more stable; when the latter is high in dosage, the adsorption performance of the product is better; the method adopts ICP-AES to test Mg in the solution²⁺、Fe³⁺And Ca²⁺Plasma concentration of metal ions and by adding MgCl₂，FeCl₃And CaCl₂The molar ratio of metal ions in the solution is adjusted, preferably, the molar ratio of the metal elements in the mixed system is controlled to be Mg/Ca of 1:3 to 3:1, [ Ca + Mg [ ]]2:1, Mg synthesized by the invention due to the existence of ferric iron_2-xCa_xFeCl hydrotalcite is reddish.

NaOH solution or NH for metal ion precursor mixed solution₃·H₂And (3) strongly stirring when the pH value of the solution is regulated to ensure uniform mixing, crystallizing the mixed solution at a constant temperature of 60-80 ℃ for 4-8 hours under the optimal condition of crystallization treatment, dehydrating the crystallized suspension by adopting filtration, filter pressing or centrifugation and the like, and drying naturally as far as possible or drying at a temperature of not more than 90 ℃ or spray drying.

Example 1

The embodiment provides a comprehensive utilization method of titanium slag, which comprises the following steps:

(1) taking 10g of ground titanium-containing electric furnace molten slag, uniformly mixing the ground titanium-containing electric furnace molten slag with 12g of solid sodium hydroxide in a graphite crucible, then putting the graphite crucible into a muffle furnace, heating the graphite crucible to 600 ℃ along with the furnace, preserving the temperature for 2 hours, taking out the graphite crucible, cooling, and rapidly crushing and grinding the co-molten slag in a dry environment to 120 meshes;

(2) putting 3g of ground eutectic slag into a beaker, adding 150ml of distilled water, electromagnetically stirring for 1 hour, filtering, drying the water leaching slag, and grinding to 100 meshes;

(3) putting 4g of dried water leaching residue into a triangular flask, adding 200ml of 0.6mol/L diluted hydrochloric acid, performing ultrasonic treatment for 15min, heating the solution to 60 ℃, condensing and refluxing for 6h, and filtering after stirring to obtain the product mainly containing Mg²⁺、Fe³⁺And Ca²⁺The metal salt filtrate and the filter residue;

(4) drying the filter residue, grinding the filter residue to 100 meshes, and then putting the filter residue into a muffle furnace at 450 ℃ to calcine for 1h to obtain the nano titanium dioxide;

(5) detection ofMeasuring Mg in the filtrate²⁺、Fe³⁺And Ca²⁺Is supplemented with MgCl₂，FeCl₃And CaCl₂Making Mg/Ca 2:1, [ Ca + Mg ] in the mixed system]Adjusting the pH of the solution to 10.0 by using 1mol/L NaOH solution, crystallizing the mixed solution at the constant temperature of 70 ℃ for 6 hours, centrifuging and drying to obtain Mg_2-xCa_xA FeCl-type Layered Double Hydroxide (LDH);

(6) TiO prepared in the step (4)₂With the Mg obtained in step (5)_2-xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1:5 and uniformly mixed, and then the mixture is ground at 400rpm for 3h and then calcined at 300 ℃ for 2h to prepare TiO₂/Mg_2-xCa_xA FeCl composite material.

Example 2

(1) taking 10g of ground titanium-containing electric furnace molten slag, uniformly mixing the ground titanium-containing electric furnace molten slag with 15g of solid sodium hydroxide in a graphite crucible, then putting the graphite crucible into a muffle furnace, heating the graphite crucible to 500 ℃ along with the furnace, keeping the temperature for 1 hour, taking out the graphite crucible, cooling, and rapidly crushing and grinding the co-molten slag in a dry environment to 120 meshes;

(2) 3g of ground eutectic slag is put into a beaker, 300ml of distilled water is added into the beaker, the mixture is electromagnetically stirred for 1 hour and then filtered, and the water leaching slag is ground into 100 meshes after being dried;

(3) placing 4g of dried water leaching residue into a triangular flask, adding 120ml of 0.6mol/L dilute hydrochloric acid, performing ultrasonic treatment for 15min, heating the solution to 40 ℃, condensing and refluxing for 8h, stirring, and filtering to obtain the product mainly containing Mg²⁺、Fe³⁺And Ca²⁺The metal salt filtrate and the filter residue;

(5) detecting Mg in the filtrate²⁺、Fe³⁺And Ca²⁺Is supplemented with MgCl₂，FeCl₃And CaCl₂Making Mg/Ca in the mixed system 1:3, [ Ca + Mg]Adjusting the pH of the solution to 9.0 with 1mol/L NaOH solution, crystallizing the mixed solution at the constant temperature of 60 ℃ for 4 hours, centrifuging the solution,Drying to obtain Mg_2-xCa_xA FeCl-type Layered Double Hydroxide (LDH);

(6) TiO prepared in the step (4)₂With the Mg obtained in step (5)_2-xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1:1 and uniformly mixed, and then the mixture is ground at 300rpm for 2h and then calcined at 300 ℃ for 1h to prepare TiO₂/Mg_2-xCa_xA FeCl composite material.

FIG. 2 is an XRD (X-ray diffraction) pattern of nano titanium dioxide obtained from the slag of the titaniferous electric furnace in the embodiment, and no other diffraction peaks are found in the XRD pattern, which shows that the rutile type titanium dioxide prepared by the invention has high purity.

FIG. 3 is an SEM image of nano-titania obtained from the slag of the titanium-containing electric furnace in this example, and it is clear from the results in the figure that all the obtained nano-titania are needle-like agglomerated rutile-type titania.

FIG. 4 shows Mg obtained from the slag of the titaniferous electric furnace in the present example_2-xCa_xThe XRD pattern of FeCl-type Layered Double Hydroxide (LDH) shows that characteristic diffraction peaks of LDHs at diffraction angles 2 theta of 11.6 degrees, 23.1 degrees, 29.5 degrees and 38.6 degrees respectively correspond to (003), (006), (009) and (015) crystal planes of LDH, and therefore Mg is successfully synthesized_2-xCa_xFeCl-type layered double hydroxide hydrotalcite.

FIG. 5 shows Mg obtained from the slag of the titaniferous electric furnace in the present example_2-xCa_xThe SEM image of FeCl-type layered double hydroxide can show that the sample has a flaky structure, good dispersion, no agglomeration and wide particle size distribution.

Example 3

(1) taking 10g of ground titanium-containing electric furnace molten slag, uniformly mixing the ground titanium-containing electric furnace molten slag with 10g of solid sodium hydroxide in a graphite crucible, then putting the graphite crucible into a muffle furnace, heating the graphite crucible to 500 ℃ along with the furnace, keeping the temperature for 1 hour, taking out the graphite crucible, cooling, and rapidly crushing and grinding the co-molten slag in a dry environment to 120 meshes;

(2) 3g of ground eutectic slag is put into a beaker, 30ml of distilled water is added, the mixture is electromagnetically stirred for 1 hour and then filtered, and the water leaching slag is ground to 100 meshes after being dried;

(3) placing 4g of dried water leaching residue into a triangular flask, adding 240ml of 0.6mol/L dilute hydrochloric acid, performing ultrasonic treatment for 15min, heating the solution to 60 ℃, condensing and refluxing for 4h, stirring, and filtering to obtain the product mainly containing Mg²⁺、Fe³⁺And Ca²⁺The metal salt filtrate and the filter residue;

(5) detecting Mg in the filtrate²⁺、Fe³⁺And Ca²⁺Is supplemented with MgCl₂，FeCl₃And CaCl₂Making Mg/Ca in the mixed system equal to 3:1, [ Ca + Mg]Adjusting the pH of the solution to 11.0 by using 30% dilute ammonia water, crystallizing the mixed solution at the constant temperature of 80 ℃ for 8 hours, centrifuging and drying to obtain Mg_2-xCa_xA FeCl-type Layered Double Hydroxide (LDH);

(6) TiO prepared in the step (4)₂With the Mg obtained in step (5)_2-xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1:10 and uniformly mixed, and then the mixture is ground at 500rpm for 4 hours and then calcined at 300 ℃ for 3 hours to prepare TiO₂/Mg_2-xCa_xA FeCl composite material.

Comparative example 1

This comparative example provides a method of comprehensively utilizing titanium slag, which is different from example 1 in that Mg/Ca is 4:1 and [ Ca + Mg ]/Fe is 2:1 in step (5).

Comparative example 2

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that the temperature of 90 ℃ is kept constant for crystallization for 6 hours in the step (5).

Comparative example 3

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that in the step (5), 1mol/L NaOH solution is used for adjusting the pH value to 11.5.

Comparative example 4

The comparative example provides a comprehensive utilization method of titanium slag and implementationExample 1 differs from this in that step (6) is: TiO prepared in the step (4)₂With the Mg obtained in step (5)_2-xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1:0.5 and uniformly mixed, and then the mixture is ground at 400rpm for 3h and then calcined at 300 ℃ for 2h to prepare TiO₂/Mg_2-xCa_xA FeCl composite material.

Comparative example 5

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that the calcining condition in the step (6) is 400 ℃ for 2 h.

Comparative example 6

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that the grinding speed in the step (6) is 600rpm, and the grinding time is 3 h.

Comparative example 7

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that the calcining condition in the step (4) is calcining for 1h at 500 ℃.

Comparative example 8

The comparison example provides a comprehensive utilization method of titanium slag, and compared with the example 1, the difference is that the step (1) is as follows: the roasting condition is that the roasting is carried out for 2 hours at 450 ℃.

Test examples

Organic matters in sewage are simulated by rhodamine B, inorganic matters in water are simulated by sodium Triphosphate (TPP), and TiO prepared by the methods of examples 1 to 3 and comparative examples 1 to 8 of the invention₂/Mg_2-xCa_xFeCl degrades rhodamine B in water and adsorbs sodium Triphosphate (TPP) in water under the condition of natural illumination.

TiO₂/Mg_2-xCa_xThe experimental method for degrading rhodamine B by using the FeCl composite material comprises the following steps: 200mL of 5mg/L rhodamine B solution is put into a photoreactor, and then 0.1g of TiO is added₂/Mg_2-xCa_xAnd electromagnetically stirring the FeCl composite material for 20min under a dark state, then turning on a xenon lamp for illumination, sampling every 15min and testing the absorbance of the FeCl composite material.

TiO₂/Mg_2-xCa_xThe experimental method for the adsorption of the FeCl composite material to the sodium Triphosphate (TPP) comprises the following steps: 200mL of 200mg/L sodium Triphosphate (TPP) solution was placed in a photoreactor, followed by the addition of 0.1g TiO₂/Mg_2-xCa_xPerforming oscillation adsorption reaction on FeCl composite material in a water bath constant temperature oscillator at 25 ℃, taking supernatant after 90min, measuring the concentration of sodium Triphosphate (TPP) in the supernatant, and calculating TiO when the adsorption reaction is performed for 90min₂/Mg_2-xCa_xAdsorption rate of FeCl composite to sodium Triphosphate (TPP).

TiO prepared in example 1₂/Mg_2-xCa_xThe result of degrading rhodamine B in water by FeCl under the natural illumination condition is shown in FIG. 6(a), and the result in FIG. 6(a) shows that the absorbance is reduced along with the extension of the illumination time; FIG. 6(b) is TiO₂/Mg_2- _xCa_xThe graph shows that the light degradation efficiency of the FeCl composite material to the rhodamine B solution changes, and the result shows that TiO reacts for 90min₂/Mg_2-xCa_xThe degradation rate of the FeCl composite material to rhodamine B reaches 80 percent.

TiO prepared in example 1₂/Mg_2-xCa_xThe results of the experiment of adsorbing sodium Triphosphate (TPP) by FeCl composite material are shown in FIG. 7, and it can be seen from the results in the figure that TiO reacts for 90min₂/Mg_2-xCa_xThe adsorption rate of the FeCl composite material to sodium Triphosphate (TPP) reaches 98.9%.

TiO prepared in examples 1 to 3 and comparative examples 1 to 8₂/Mg_2-xCa_xThe test results of degrading rhodamine B in water and adsorbing sodium Triphosphate (TPP) in water by FeCl under natural illumination conditions are shown in the following table.

Examples	Photodegradation efficiency (%)	Adsorption efficiency (%)
			Example 1	80	98.9
Example 2	78	98.5
			Example 3	79	98.2
Comparative example 1	45	60.5
			Comparative example 2	52	68.2
Comparative example 3	46	58.7
			Comparative example 4	40	59.8
Comparative example 5	58	62.6
			Comparative example 6	60	70.5
Comparative example 7	55	61.9
			Comparative example 8	42	52.6

From the above table results, it can be seen that: TiO obtained under the conditions of example 1₂/Mg_2-xCa_xThe FeCl composite material has the best effect of degrading rhodamine B in water and adsorbing sodium Triphosphate (TPP) under the natural illumination condition, and the inventor finds that the TiO can be adsorbed by changing any condition in the method through a large amount of experiments₂/Mg_2-xCa_xThe degradation and adsorption properties of the FeCl composite material are affected.

While the invention has been described with respect to specific embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention; those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention; meanwhile, any equivalent changes, modifications and alterations of the above embodiments according to the spirit and techniques of the present invention are also within the scope of the present invention.

Claims

1. The comprehensive utilization method of the titanium slag is characterized by comprising the following steps:

(3) will be provided withMixing the water leaching residue and hydrochloric acid, stirring, performing acid leaching, and performing solid-liquid separation to obtain the product mainly containing Mg²⁺、Fe³⁺And Ca²⁺The metal salt filtrate and the filter residue;

(5) detecting Mg in the filtrate²⁺、Fe³⁺And Ca²⁺Is supplemented with MgCl₂，FeCl₃And CaCl₂Making Mg/Ca = 1: 3-3: 1, [ Ca + Mg ] in the mixed system]Fe = 2:1, adjusting the pH value of the solution, crystallizing the mixed solution at constant temperature, centrifuging and drying to obtain Mg_2−xCa_xA FeCl-type layered double hydroxide;

(6) TiO prepared in the step (4)₂With the Mg obtained in step (5)_2−xCa_xFeCl is dispersed in ethanol according to the mass ratio of 1: 1-10, is uniformly mixed, and is ground and calcined to prepare TiO₂/Mg_2−xCa_xA FeCl composite material.

2. The comprehensive utilization method of titanium slag according to claim 1, wherein the mass ratio of the molten slag of the titanium-containing electric furnace to the solid sodium hydroxide in the step (1) is 1: 1-1.5.

3. The comprehensive utilization method of titanium slag according to claim 1, wherein the roasting condition in step (1) is 500-700 ℃ for 1-3 h.

4. The comprehensive utilization method of titanium slag according to claim 1, wherein in the step (2), the titanium slag is ground to more than 100 meshes, and the solid-liquid mass ratio is 1:10 to 100.

5. The comprehensive utilization method of titanium slag according to claim 1, wherein the concentration of hydrochloric acid in step (3) is 0.3-1.5 mol/L, and the liquid-solid mass ratio is 30-60: 1, stirring for 4-8 h at the leaching temperature of 40-60 ℃.

6. The comprehensive utilization method of titanium slag according to claim 1, wherein the calcination condition in step (4) is 450 ℃ for 1 hour.

7. The comprehensive utilization method of titanium slag according to claim 1, characterized in that in step (5), crystallization is carried out at a constant temperature of 60-80 ℃ for 4-8 hours.

8. The method for comprehensively utilizing titanium slag according to claim 1, wherein the pH of the solution in the step (5) is adjusted to be NaOH solution or NH solution₃·H₂And adjusting the pH value to 9.0-11 by using O.

9. The comprehensive utilization method of titanium slag according to claim 1, wherein the grinding speed in step (6) is 300-500 rpm, and the grinding time is 2-4 h.

10. The comprehensive utilization method of titanium slag according to claim 1, wherein the calcination condition in step (6) is 300 ℃ for 1-3 h.