CN116040688A - Iron red product and its preparation method and application - Google Patents

Abstract

The invention provides an iron oxide red product, and a preparation method and application thereof. The method comprises the following steps: mixing and stirring the waste liquid or the waste liquid from which the solid impurities are removed with a calcareous raw material, and carrying out neutralization of waste acid and growth and conversion of a crystal form to obtain slurry; wherein the waste liquid is sulfuric acid waste liquid containing iron ions; separating liquid from the slurry, oxidizing the liquid, and then performing solid-liquid separation to obtain an iron oxide red precursor solid material; and scattering and calcining the iron oxide red precursor solid material to obtain the iron oxide red. The iron oxide red product comprises the iron oxide red precursor solid material and the iron oxide red prepared by the method. Such applications include use in the preparation of colorants, coatings, inks, cosmetics, foods, medical targeted therapeutic drugs, paints or combustion catalysts. The method can effectively separate the main valuable element iron in the sulfuric acid process titanium dioxide waste acid liquid, and produce high-value nanoscale iron oxide red, thereby being beneficial to realizing the conversion of a sulfuric acid process titanium dioxide enterprise from a pollution type enterprise to a clean production enterprise.

Description

Iron red product and its preparation method and application

technical field

The invention relates to the field of processing and utilization of industrial waste, in particular to an iron red product and its preparation method and application.

Background technique

At present, there are mainly two kinds of sulfuric acid method and chlorination method in the production of titanium dioxide. In the production process of sulfuric acid titanium dioxide, a large amount of titanium dioxide waste acid will be produced. For the treatment of titanium white waste acid by sulfuric acid method, at present, the waste acid is homogenized and then mixed with ordinary limestone to neutralize it. After solid-liquid separation, a part of primary titanium gypsum containing iron is produced, and the filtrate is aerated and oxidized and then added with milk of lime. Secondary neutralization and solid-liquid separation again produce secondary titanium gypsum with higher iron content. The traditional process of treating titanium white waste acid from the sulfuric acid method produces titanium gypsum because of its high iron content and red color. It is also called red gypsum, and its water content is as high as 40%-50%. Or Sinotrans centralized stacking. Titanium gypsum has a fine particle size and contains more weakly acidic free water. Long-term stockpiling not only occupies a large amount of land, but also requires high transportation and disposal costs. It also has potential risks of water pollution and dust pollution. It has become the main problem faced by sulfuric acid titanium dioxide production enterprises. question. For the treatment of high-acid wastewater, there are treatment methods such as concentration process or membrane filtration process to improve the concentration and quality of acid, but they have not been widely promoted due to high cost. Other comprehensive utilization technologies of sulfuric acid titanium dioxide waste acid have not been popularized and applied in actual production due to many reasons such as technical difficulty, complicated process or high cost. A large amount of stockpiling of titanium gypsum not only occupies land and pollutes the environment, but also causes a great economic burden on titanium dioxide enterprises. It is urgent to adopt new technological methods to treat the waste titanium dioxide acid from the sulfuric acid process, so as to realize the effective utilization of iron and sulfur in the waste acid. Separate and resource.

Contents of the invention

The object of the present invention is to solve at least one of the above-mentioned deficiencies in the prior art. One of the objects of the present invention is to provide a method that can utilize titanium white waste acid to produce iron oxide red and reduce environmental pollution.

In order to achieve the above object, the present invention provides a preparation method of iron red product.

The method comprises the following steps: mixing and stirring the waste liquid or the waste liquid from which solid impurities have been removed and the calcareous raw material, neutralizing the waste acid and transforming crystal growth to obtain a slurry; wherein, the waste liquid is sulfuric acid containing iron ions Waste liquid: separate the liquid from the slurry, oxidize the liquid, and then separate the solid and liquid to obtain the iron red precursor solid.

According to an exemplary embodiment of the present invention, the method may further include the step of breaking up and calcining the iron red precursor solid to obtain iron oxide red.

According to an exemplary embodiment of the present invention, the concentration of H ₂ SO ₄ in the sulfuric acid waste liquid containing iron ions is below 10%.

According to an exemplary embodiment of _the present invention, the sulfuric acid waste liquid containing iron ions includes: waste acid directly produced by sulfuric acid production of titanium white, or waste acid produced by sulfuric acid production of titanium white and adjusted by _H2SO4 concentration. acid.

According to an exemplary embodiment of the present invention, the waste acid may include: waste liquid with a H ₂ SO ₄ concentration of 2-5% generated during the sulfuric acid titanium dioxide production process.

According to an exemplary embodiment _of the present invention, the waste acid _produced in the sulfuric acid titanium dioxide production process and adjusted by the concentration of _H2SO4 may include: the concentration of _H2SO4 produced in the sulfuric acid titanium dioxide production process is After homogenizing the 2-5% waste liquid and the waste liquid with a _H2SO4 concentration of 15-20% _, the waste liquid with _{a H2SO4} concentration of 3-10% is obtained.

According to an exemplary embodiment of the present invention, the sulfuric acid waste liquid containing iron ions may include waste acid liquid produced by ferrous sulfate lithium iron phosphate battery, waste acid liquid after extracting ferrous sulfate, or produced by hydrometallurgy of iron-containing waste acid.

According to _an exemplary embodiment of the present invention, the sulfuric acid waste liquid containing iron ions may include waste acid directly produced by sulfuric acid production of titanium white, waste acid produced by sulfuric acid production of titanium white and adjusted by _H2SO4 concentration, A mixture of at least two of the waste acid solution produced by ferrous sulfate lithium iron phosphate battery, the waste acid solution after extracting ferrous sulfate, and the iron-containing waste acid solution produced by hydrometallurgy.

According to an exemplary embodiment of the present invention, the method for removing solid impurities may include standing, and the standing time may be 3-6 hours.

According to an exemplary embodiment of the present invention, the method may further include a step of: adding a reducing agent during the standing process.

According to an exemplary embodiment of the present invention, the calcareous raw material includes one or more of limestone, calcium carbide, lime and milk of lime; and/or, the pH is controlled to be less than or equal to 5 during the conversion process.

According to an exemplary embodiment of the present invention, the oxidation includes: at least one of aeration oxidation and oxidation by adding an oxidizing agent; wherein, during the oxidation process, the pH of the control system is less than 7; the oxidizing agent includes hydrogen peroxide.

According to an exemplary embodiment of the present invention, the method may further include the step of: washing the solid remaining after the liquid is separated from the slurry, and combining the generated washing waste liquid with the slurry from the slurry The separated liquids are oxidized together.

According to an exemplary embodiment of the present invention, the method may further include the step of: adding a reducing agent and a pH regulator to all or part of the liquid obtained from the solid-liquid separation, and then using it to wash the obtained slurry The solid that remains after the liquid has been separated out.

In another aspect, the invention provides an iron red product.

The iron red product may include the iron red precursor solid material prepared by the above-mentioned method, and/or the iron oxide red prepared by the above-mentioned method.

In yet another aspect, the present invention provides an application of iron oxide red in the preparation of colorants, coatings, inks, cosmetics, food, medical targeted therapy drugs, coatings, electromagnetic wave absorbing materials or combustion catalysts.

Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

(1) The present invention can effectively separate the valuable element iron in the waste acid solution, especially the waste acid solution of titanium dioxide produced by the sulfuric acid process, and produce high-value nano-scale iron oxide red, so as to achieve the purpose of reusing waste resources.

(2) The production process of the present invention does not produce other solid waste and waste gas, and the waste water produced can be discharged up to the standard after being treated, which belongs to the clean production and environment-friendly technology.

(3) The iron red product prepared by the present invention has wide application in various fields, and can realize 100% consumption.

Description of drawings

The above and other objects and features of the present invention will become clearer through the following description in conjunction with the accompanying drawings, wherein:

Fig. 1 shows the method flowchart of preparing iron oxide red from titanium dioxide waste acid of an exemplary embodiment of the present invention;

Fig. 2 shows the iron red precursor solid material product map that the embodiment of the present invention 1 prepares;

Fig. 3 shows the product picture of the iron oxide red powder that the embodiment of the present invention 1 prepares;

Fig. 4 shows a diffractogram of the iron oxide red powder that the embodiment of the present invention 1 prepares;

Fig. 5 shows a scanning electron micrograph of the iron oxide red powder that the embodiment of the present invention 1 prepares;

Fig. 6 shows the product figure of the iron oxide red powder that the embodiment of the present invention 2 prepares;

Fig. 7 shows a diffractogram of the iron oxide red powder that the embodiment of the present invention 2 prepares;

Fig. 8 shows a scanning electron micrograph of the iron oxide red powder that the embodiment of the present invention 2 prepares;

Fig. 9 shows another scanning electron micrograph of the iron oxide red powder prepared in Example 2 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention.

Exemplary Embodiment 1

This exemplary embodiment provides a method for preparing an iron red product, which is iron red precursor solid material. The method comprises the steps of:

S1. Removing solid impurities in titanium white waste acid from sulfuric acid process.

In this embodiment, the step of removing solid impurities may include: standing or filtering. Of course, the present invention is not limited thereto, and other methods capable of realizing solid-liquid separation can also be used to remove solid impurities.

In this embodiment, the concentration of H ₂ SO ₄ in the titanium white waste acid from the sulfuric acid process is below 10%. If the concentration of H ₂ SO ₄ is greater than 10%, the calcareous raw material (such as limestone) mixed in the subsequent step S2 will easily form a package, which will lead to uneven reaction, and the excessive concentration of H ₂ SO ₄ will also cause difficulty in stirring.

Further, the concentration of _H2SO4 in the waste acid can be 2% to 10%, such as 9.9%, 8%, 7.5%, 5.9%, 5%, 4.9%, 4%, 3%, 2.5%, 2.1%, _etc. . If the concentration is lower than the lower limit of 2%, it will result in low yield and thus high cost. Still further, the concentration of H ₂ SO ₄ in the titanium white waste acid from the sulfuric acid process is 2-6%. It should be noted that the concentration of H ₂ SO ₄ referred to in this patent refers to the mass fraction.

As an embodiment of the present invention, the waste acid of titanium white produced by sulfuric acid process may be the waste acid directly produced by sulfuric acid process of titanium white, for example, the waste acid with H ₂ SO ₄ concentration of 2-5%.

As another embodiment of the present invention, the waste acid of titanium white produced by sulfuric acid process may be the waste acid produced by sulfuric acid process of titanium white and adjusted by the concentration of H ₂ SO ₄ . Specifically _, the concentration of H ₂ SO ₄ is adjusted so that the concentration of _{H 2 SO 4} is 2-10%, such as 3-6%. For example, adding high-concentration _H2SO4 solution to sulfuric acid titanium dioxide waste acid whose _{H2SO4 concentration} is less than 2%, for example _, adding water to sulfuric acid titanium dioxide waste acid with _{H2SO4 concentration} greater than 10% Dilute, and for example _, mix the sulfuric acid titanium dioxide waste acid _with low _H2SO4 concentration and the sulfuric acid titanium dioxide waste acid with high _H2SO4 concentration for homogeneity.

As an example, in the production process of some sulfuric acid titanium dioxide enterprises, a large amount of dilute acid wastewater with a sulfuric acid content of 2-5% and a small amount of high-acid wastewater with a sulfuric acid content of 15-25% will be produced. The invention can directly utilize dilute acid wastewater with a sulfuric acid content of 2-5%. The present invention can also pre-homogenize 15-25% high-acid wastewater and 2-5% dilute acid wastewater into untreated waste acid solution with a concentration of less than 10% (for example, 3-6%) for subsequent production.

In this embodiment, when the spent acid contains ferric ions, the method can also add a reducing agent to the spent acid or the spent acid that is removing solid impurities, so that the ferric ions can be reduced to ferrous ions, improve the recovery rate of iron. For example, in the case of choosing standing to remove solid impurities, a reducing agent is added during the standing process, and the reducing agent may include at least one of oxalic acid and iron powder.

It should be noted that step S1 in this application is an unnecessary link, and this link can also be omitted, and the subsequent steps can be performed directly.

S2. Mixing and stirring the acidic waste liquid after removal of solid impurities and the calcareous raw material to perform crystal growth transformation to obtain a slurry.

In this embodiment, the calcareous raw material includes one or more of limestone, calcium carbide, lime and lime milk, and limestone is selected in this embodiment.

In this embodiment, the waste acid solution after standing still is sent to the crystal growth converter, and limestone is added to stir and transform at the same time. Monitor pH or acidity changes during crystal growth and conversion, and control pH ≤ 5, for example, control pH to 1, 2, 3, 4, 4.5, etc. If the pH is greater than 5, iron precipitation will occur, which will affect the iron production rate.

S3. Separating the liquid from the slurry, aerating and oxidizing the liquid and controlling the pH of the system to be less than 7, and then performing solid-liquid separation to obtain the iron red precursor solid material.

In this embodiment, the slurry after crystal growth and conversion is placed in a solid-liquid separation device for solid-liquid separation, and the filtrate is collected in an aeration device for aeration and oxidation.

In this embodiment, the purpose of aeration is to oxidize ferrous ions to ferric ions, so as to increase the recovery rate of iron. During the aeration process, an oxidizing agent can be added to speed up the oxidation rate; wherein, the oxidizing agent includes hydrogen peroxide, which will not introduce other impurity ions to cause water pollution.

In this embodiment, during the aeration process, an appropriate amount of pH regulator is added to control the pH to be less than 7, for example, to control the pH to 1, 2, 3, 4, 5, 6; to produce a solid iron red precursor, which is separated by solid-liquid separation Finally, the iron red precursor solid material is obtained, and Fig. 2 shows the iron red precursor solid material prepared by the present invention.

In this embodiment, during the process of aeration, the alkaline pH regulator can be slowly and continuously added to make the oxidation process continue. The adding amount of alkaline pH regulator should ensure that the reaction process is carried out continuously. If no alkaline pH regulator is added, the oxidation reaction will be interrupted and the quality of the product will be affected. The alkaline pH adjuster may include at least one of soda ash, soda lye, caustic soda and caustic lye.

It should be noted that, in addition to aerated oxidation, the present application can also directly choose to add an oxidizing agent to achieve oxidation, and the oxidizing agent may include hydrogen peroxide. During the oxidation process, the alkaline pH regulator can also be added slowly and continuously, so that the oxidation process can be carried out continuously.

S4. Wash the solids remaining after the liquid is separated from the slurry, and aerate the resulting washing waste liquid together with the liquid separated from the slurry.

S5. Adding a reducing agent and a pH regulator to all or part of the liquid obtained by solid-liquid separation, and then washing the solid remaining after the liquid is separated from the slurry. The remaining liquid is discharged up to standard after water treatment, realizing the closure of the entire process flow.

Exemplary embodiment 2

This exemplary embodiment provides an iron red precursor solid material. The iron red precursor solid material includes the iron red precursor solid material prepared by the method for preparing iron red precursor solid material from titanium white waste acid in exemplary embodiment 1.

Exemplary embodiment 3

This exemplary embodiment provides a method for preparing an iron red product, which is iron oxide red. The method can obtain iron oxide red by breaking up and calcining the iron red precursor solid obtained in Exemplary Example 1. The method may include the steps of:

A1. Stand still the acidic waste liquid with the concentration of H ₂ SO ₄ below 10%. This step may be the same as S1 in Exemplary Embodiment 1. Likewise, this step can also be omitted, and the subsequent steps can be directly performed.

A2. Mix and stir the acidic waste liquid after standing with the calcareous raw material to carry out crystal growth transformation to obtain a slurry. This step may be the same as S2 in Exemplary Embodiment 1.

A3. Separating the liquid from the slurry, aerating the liquid and controlling the pH of the system to be less than 7, and then performing solid-liquid separation to obtain the iron red precursor solid material. This step may be the same as S3 in Exemplary Embodiment 1.

A4. Dispersing and calcining the iron red precursor solid material to obtain iron oxide red.

In this embodiment, the method may further include steps S4 and S5 in Exemplary Embodiment 1.

Exemplary Embodiment 4

This exemplary embodiment provides a method for preparing an iron red product. Fig. 1 has shown the method flowchart of this exemplary embodiment, and described method comprises the following steps:

High-concentration waste acid (concentration 15-25%) and low-concentration waste acid (concentration 2-5%) produced by titanium dioxide sulfate production enterprises are pre-homogenized into untreated waste acid liquid with a concentration of 3-6%.

The homogeneous waste acid solution or a separate low-concentration waste acid solution is placed in an acid-resistant container for static treatment.

After standing still, the waste acid solution is sent to the crystal growth converter, and at the same time, limestone is added to stir and transform. Monitor pH or acidity changes during crystal growth and conversion, and control pH to be less than or equal to 5. The slurry after crystal growth and transformation is sent to solid-liquid separation equipment for solid-liquid separation.

The filtrate from solid-liquid separation is collected into the aeration device for aeration, and an oxidant can be added to speed up the oxidation rate; at the same time, an appropriate amount of pH regulator is added to control the pH to be less than 7, and a solid iron red precursor is produced. After solid-liquid separation, the obtained Iron red precursor solid material. The iron red precursor solid material is broken up and calcined to produce nano-scale iron oxide red powder.

Part of the liquid produced by separating the iron red precursor solid can be used as a washing solution after adding a reducing agent and a pH regulator. The remaining liquid is discharged up to standard after water treatment, realizing the closure of the entire process flow.

Exemplary Embodiment 5

This exemplary embodiment provides an iron oxide red product, which includes the iron oxide red prepared by the iron red product preparation method described in exemplary embodiment 3 or 4.

In this embodiment, the iron oxide red iron grade is ≥ 56%; the iron oxide red can be nano-scale, with a particle size of 20-800nm, such as 30, 40, 50, 100, 300, 400, 500, 600 , 700, 790nm, etc., the shape is spherical. Of course, the present invention can also prepare non-nano-scale iron oxide red, such as micron-scale.

In order to better understand the exemplary embodiments of the present invention, it will be further described below in conjunction with specific embodiments.

Example 1

A sulfuric acid titanium dioxide production enterprise used the patented technology of this invention to treat low-concentration waste acid, with a treatment capacity of 5-6m ³ /h. The content of H ₂ SO ₄ in the homogeneous waste acid liquid adjusted by the concentration of H ₂ SO ₄ is detected to be 3-4%, and the content of TFe is 5-6g/L. Put the homogeneous waste acid solution adjusted by _H2SO4 concentration into an acid-resistant container with a volume of 20 cubic meters and let it stand for 3 hours, during which time _1-2 % oxalic acid is added to the stand solution. The reduced waste acid solution is metered into multiple crystal growth converters with a volume of 3 cubic meters, and limestone is added to stir at the same time to make the crystal growth and transformation. The pH and acidity changes are monitored throughout the process, and the pH is controlled at 3-4. The slurry after crystal growth and transformation is sent to a centrifugal filter for solid-liquid separation.

The filtrate from solid-liquid separation and the liquid produced by washing and separating the solids are collected into the aeration device for aeration, and hydrogen peroxide is added during the aeration process to speed up the oxidation speed; continuously add soda ash to adjust the pH to about 6, and the aeration tank The solid iron red precursor is gradually produced, and the iron red precursor solid material shown in Figure 2 is obtained through solid-liquid separation. It should be noted that Figure 2 is a grayscale image, and the iron red precursor solid itself is yellowish brown. The solid material of the iron red precursor is broken up and calcined to produce red iron oxide powder as shown in Figure 3. It should be noted that Figure 3 is a grayscale image, and the red iron oxide powder itself is reddish brown. The phase analysis of the red iron oxide powder is shown in Figure 4. It is obvious that the main phase is Fe ₂ O ₃ . The composition _of iron oxide red powder is tested, and the test results are shown in Table 1. The mass ratio of _Fe2O3 in iron oxide red powder is 95.6%, which is 66.92% when converted into iron grade; the iron oxide red powder is scanned by electron microscope, The results are shown in Figure 5. It can be seen from the figure that the particle size of the iron oxide red powder is between 30-50nm, such as 32.49nm, 34.05nm and 36.65nm shown in Figure 5; the morphology is spherical.

Table 1

Element <![CDATA[Fe₂O₃]]> CaO MgO <![CDATA[SiO₂]]> <![CDATA[Al₂O₃]]> <![CDATA[TiO₂]]> other total Contentwt% 95.6 0.15 0.065 0.81 0.55 0.032 2.793 100.00

Example 2

A sulfuric acid titanium dioxide production enterprise uses the patented technology of this invention to treat low-concentration waste acid solution, with a treatment capacity of 80-100m ³ /h. The _H2SO4 content of _the waste acid solution is 2-3%, and the TFe content is 3-4g/L. Put the waste acid liquid into two acid-resistant containers with a volume of 200 cubic meters and let it stand for 5 hours, then meter it into multiple crystal growth converters with a volume of 10 cubic meters, add limestone and stir to make the crystal growth and transformation, the whole process Monitor the pH and acidity changes, and control the pH to 2.5-3.5. The slurry after crystal growth and conversion is sent to a filter press for solid-liquid separation.

The filtrate from solid-liquid separation is collected into the aeration device for aeration. During the aeration process, hydrogen peroxide is added to speed up the oxidation rate; soda lye is added to adjust the pH to 5.5, and the solid iron red precursor is gradually produced in the aeration tank, which is obtained by solid-liquid separation. Iron red precursor solid material. The iron red precursor solid material is dispersed and calcined to produce red iron oxide powder as shown in Figure 6. It should be noted that Figure 6 is a grayscale image, and the red iron oxide powder itself is reddish brown. The phase analysis of the red iron oxide powder is shown in Figure 7. It is obvious that the main phase is Fe ₂ O ₃ . The iron oxide red powder was tested for components, and the test results are shown in Table 2. The mass ratio of Fe ₂ O ₃ in the iron oxide red powder was 89.13%, which was 62.39% when converted to iron grade. The iron oxide red powder is scanned by electron microscope, and the results are shown in Figure 8 and Figure 9. It can be seen from the figure that the particle size of the iron oxide red powder is between 300-800nm, such as 567nm and 754nm shown in Figure 8, and its appearance is spherical .

Table 2

Element <![CDATA[Fe₂O₃]]> CaO MgO <![CDATA[SiO₂]]> <![CDATA[Al₂O₃]]> <![CDATA[TiO₂]]> other total Contentwt% 89.13 3.36 0.082 2.46 1.16 0.068 3.74 100.00

Certainly, the method for preparing the iron red product of the present invention is not only limited to the treatment of the waste acid solution of sulfuric acid process titanium white, the present invention can also be used for the waste acid solution produced by ferrous sulfate lithium iron phosphate battery, the waste acid solution after extracting ferrous sulfate Acid solution, iron-containing waste acid solution produced by hydrometallurgy, etc. are processed to obtain iron red products.

Exemplary Embodiment 6

This exemplary embodiment provides an application of iron oxide red.

The iron oxide red product of the invention has excellent performance and has wide application fields. For example, it has good temperature resistance and can be applied to coloring various plastics, rubber, ceramics, and asbestos products. The iron oxide red product of the present invention can also be applied to antirust paints, middle and low grade paints, cement products, tile coloring, etc., and can also be used in fiber coloring pastes, anti-counterfeiting coatings, electrostatic copying, inks, etc. In addition, the nano-iron oxide of the present invention has non-toxicity and super ultraviolet absorption, and is suitable for cosmetic industry and powder coating. The nano-iron oxide product of the present invention can also be added to coatings, and has fine particle size, good absorption and attenuation of electromagnetic waves and sound waves, and strong absorption, dissipation and shielding effects on mid-infrared bands. In addition, the nano-iron oxide product of the present invention can also be used as a solid propellant made of a combustion catalyst, and its burning speed is about 10 times higher than that of a common propellant. The nano iron oxide of the present invention can also be used in food. It can also be used as a traction agent for medical targeted therapy drugs.

Although the present invention has been described above in conjunction with the exemplary embodiments, it should be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined in the claims. Change.

Claims (10)

1. A method for producing an iron oxide red product, comprising the steps of:

mixing and stirring the waste liquid or the waste liquid from which the solid impurities are removed with a calcareous raw material, and carrying out neutralization of waste acid and growth and conversion of a crystal form to obtain slurry; wherein the waste liquid is sulfuric acid waste liquid containing iron ions;

separating liquid from the slurry, oxidizing the liquid, and then performing solid-liquid separation to obtain the iron oxide red precursor solid material.

2. The method for producing an iron oxide red product according to claim 1, further comprising the steps of: and scattering and calcining the iron oxide red precursor solid material to obtain iron oxide red.

3. The method for producing iron oxide red according to claim 1 or 2, wherein H in the sulfuric acid waste liquid containing iron ions ₂ SO ₄ The concentration is below 10%, and comprises: waste acid directly produced by preparing titanium white by sulfuric acid method, produced by preparing titanium white by sulfuric acid method and H-phase ₂ SO ₄ At least one of waste acid with adjusted concentration, waste acid liquid generated by lithium iron phosphate battery made of ferrous sulfate, waste acid liquid after extracting ferrous sulfate and waste acid liquid containing iron generated by hydrometallurgy.

4. The method for producing an iron oxide red product according to claim 1 or 2, wherein in case the waste liquid contains ferric ions, the method further comprises the steps of: and adding a reducing agent into the waste liquid before the step of uniformly mixing the waste liquid with the calcareous raw material so as to reduce ferric ions into ferrous ions.

5. The method of producing an iron oxide red product according to claim 1 or 2, wherein the calcareous raw material comprises one or more of limestone, carbide, lime and lime milk;

and/or the number of the groups of groups,

the pH value is controlled to be less than or equal to 5 in the conversion process.

6. The method of producing an iron oxide red product according to claim 1 or 2, wherein the oxidizing comprises: at least one of aeration oxidation and additive oxidant oxidation;

wherein during the oxidation, controlling the pH of the system to be less than 7;

the oxidizing agent includes hydrogen peroxide.

7. The method for producing an iron oxide red product according to claim 1 or 2, characterized in that an alkaline pH adjuster is added during the oxidation process.

8. The method for producing an iron oxide red product according to claim 1 or 2, characterized in that the method further comprises the steps of: washing the solid remaining after the liquid is separated from the slurry, and oxidizing the generated washing waste liquid together with the liquid separated from the slurry.

9. An iron oxide red product, characterized in that the iron oxide red product comprises:

the iron oxide red precursor solid material prepared by the method according to any one of claims 1 and 3 to 8,

and/or the number of the groups of groups,

iron oxide red produced by the method of any one of claims 2-8.

10. Use of the iron oxide red according to claim 9 for the preparation of colorants, coatings, inks, cosmetics, food products, medical targeted therapeutic drugs, paints, electromagnetic wave absorbing materials or combustion catalysts.

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