Zirconium metallurgy waste alkali liquor recycling treatment method

Abstract

The invention relates to the technical field of mineral separation, in particular to a zirconium metallurgy waste alkali liquor recycling treatment method. The method comprises the following steps: chemically analyzing the contents of OH <->, Na2O and SiO2 in the zirconium metallurgy waste alkali liquid; calculating the addition amount of the white carbon black according to the reaction equations (4) and (5) of the main components in the zirconium metallurgy waste alkali liquid and the white carbon black and the modulus of the water glass to be prepared; 2 NaOH + m SiO2 > Na2O.m SiO2 + H2O (4); (5) Na2SiO3 + mSiO2-> Na2O. (m + 1) SiO2; the method comprises the following steps: adding white carbon black into zirconium metallurgy waste alkali liquor under closed and stirring conditions, and reacting to obtain water glass; according to the method, the zirconium metallurgy waste alkali liquor is turned into wealth through the method of generating the water glass, and the purpose of recycling the zirconium metallurgy waste alkali liquor can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, and in particular to a method for resource disposal of zirconium metallurgical waste alkali liquor. Background Art

[0002] Zirconium is a high melting point metal. It is easy to form an oxide film on the surface of zirconium, which is shiny, so its appearance is similar to steel. Zirconium belongs to the titanium subgroup of transition metals. Due to its special position in the periodic table, zirconium and its compounds have many unique properties. For example, zirconium atoms have a strong affinity for oxygen, zirconium compounds are highly active in aqueous solutions, colorless and non-toxic final products, and metal zirconium has a very low thermal neutron absorption cross section and other excellent nuclear properties. Zirconium is widely used in many fields of the industrial sector, including not only the ceramic industry, textile industry, paper industry, electronics industry and refractory industry that are closely related to people's lives, but also in many cutting-edge fields such as rockets and missiles, atomic energy industry, magnetohydrodynamic power generation and optical fiber communications.

[0003] The production of zirconium oxychloride (ZrOCl2·8H2O) is a very important part in the production process of metallic zirconium. Zirconium oxychloride has good solubility and is easy to purify and convert. It can be used as a raw material for the production of various products such as zirconium oxide, zirconium carbonate, zirconium sulfate, fused zirconium and metallic zirconium. It can also be directly used to make mordants, color fixers, adhesives, deodorants, flame retardants, etc. It is the zirconium compound product with the largest output and is also an important basic material for metallurgy and chemical industry.

[0004] The zircon ore commonly used in the industrial production of zirconium oxychloride is zircon (ZrSiO4), which is an orthosilicate of zirconium and has high chemical stability. It does not react with other inorganic acids except hydrofluoric acid. The decomposition methods currently used in industry include chlorination, potassium fluorosilicate sintering and alkali decomposition. The alkali decomposition method is further divided into sodium hydroxide fusion method and sodium carbonate sintering method. The sodium hydroxide fusion method has the advantages of low decomposition temperature, easy control of process conditions, large-scale production, stable product quality, high zircon decomposition rate and low cost. At present, most zirconium oxychloride manufacturers use sodium hydroxide alkali fusion zircon process to produce zirconium oxychloride.

[0005] Sodium hydroxide and zircon mainly have the following reactions:

[0006] ZrSiO4+2NaOH→Na2ZrSiO5+H2O (1)

[0007] ZrSiO4+4NaOH→Na2ZrO3+Na2SiO3+2H2O (2)

[0008] ZrSiO4+6NaOH→Na2ZrO3+Na4SiO4+3H2O (3)

[0009] Thermodynamically, all of these reactions are possible, but which reaction dominates depends on the reaction ratio, temperature and other conditions. When the molar ratio of zircon to NaOH is 1:2, the reaction mainly proceeds according to equation (1), and the product is mainly sodium zirconate; when the molar ratio is 1:4, reaction (2) is dominant, and the products are mainly sodium zirconate and sodium metasilicate. In order to create favorable conditions for leaching, it is usually necessary to allow the reaction to proceed as much as possible according to equation (2), so that its products are mainly sodium zirconate and sodium metasilicate. In this way, silicon can be removed as much as possible in the next step of water washing.

[0010] When zirconium oxychloride is produced industrially, excess NaOH is usually added to roast and melt zircon, and then the alkali melt is washed with water to remove soluble silicon and excess alkali. The washed slag is then leached with hydrochloric acid, and the zirconium enters the leachate. Finally, the low solubility of zirconium oxychloride in concentrated hydrochloric acid is used to evaporate and concentrate the leachate, and then cool and crystallize to produce zirconium oxychloride. The washing process of zirconium oxychloride production will produce alkaline waste liquid. The main components of the alkaline waste liquid are the excess NaOH added in the alkali calcination process and the Na2SiO3 formed by the reaction. The general washing process adopts a countercurrent washing process to reduce the direct water consumption and thus reduce the output of alkaline wastewater, while increasing the concentration of waste alkali liquid. At present, in the production of zirconium oxychloride, about 5m3 of zirconium oxychloride is used for every ton of zirconium oxychloride produced. 3 Waste alkali liquid is generated. A large amount of waste alkali liquid is difficult to treat and has high operating costs. If it is not managed and comprehensively utilized, it will cause environmental pollution and waste of resources. At present, no relevant reports on the resource utilization of waste alkali liquid from zirconium concentrate metallurgical washing have been found in the literature. Summary of the invention

[0011] Based on the above content, the present invention provides a method for resource disposal of zirconium metallurgical waste alkali liquor. By adding white carbon black to the zirconium metallurgical waste alkali liquor, it reacts with the residual NaOH in the waste alkali liquor to generate water glass, and the newly generated water glass can be used for mineral flotation, construction or other industries, so that the zirconium metallurgical waste alkali liquor can be turned into treasure, achieving the purpose of resource disposal of zirconium metallurgical waste alkali liquor.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] The present invention provides a method for resource disposal of zirconium metallurgical waste alkali liquor, comprising the following steps:

[0014] Step 1: OH in zirconium metallurgical waste alkali liquor - , Na2O and SiO2 contents were chemically analyzed;

[0015] Step 2, calculating the amount of white carbon black added according to the reaction equations (4) and (5) of the main components in the zirconium metallurgical waste alkali solution and white carbon black and the modulus of the water glass to be prepared;

[0016] 2NaOH+mSiO2→Na2O·mSiO2+H2O (4)

[0017] Na2SiO3+mSiO2→Na2O·(m+1)SiO2 (5)

[0018] In reaction equations (4) and (5), m and m+1 are the moduli of water glass;

[0019] Step 3, adding white carbon black to the zirconium metallurgical waste alkali solution under closed and stirring conditions to react and obtain water glass.

[0020] In a preferred embodiment of the present invention, in step 3, the reaction temperature is 15-90°C.

[0021] In a preferred embodiment of the present invention, in step 3, the reaction time is 10 minutes to 10 hours.

[0022] In a preferred embodiment of the present invention, in step 3, the stirring speed is 50-5000 r / min.

[0023] In a preferred embodiment of the present invention, in step 3, the modulus of the water glass is 1.5-3.6.

[0024] In a preferred embodiment of the present invention, step 3 further includes a step of using the prepared water glass to flotate rare earth minerals.

[0025] In a preferred embodiment of the present invention, when flotation of rare earth minerals is performed, the amount of water glass added is 2 kg / t of rare earth minerals.

[0026] The present invention discloses the following technical effects:

[0027] The present invention provides a resource disposal method suitable for alkali treatment of zirconium concentrate washing liquid, which reduces secondary environmental pollution, has a simple process, is easy to operate, and has an excellent waste utilization effect. By generating water glass, the zirconium metallurgical waste alkali liquid is turned into treasure, thereby achieving the purpose of resource disposal of zirconium metallurgical waste alkali liquid. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] At present, the large amount of waste alkali liquid generated in the production of zirconium oxychloride has the problems of difficult treatment, high operating costs, environmental pollution and waste of resources. At present, no relevant reports on effective resource utilization have been found. In view of the shortcomings of the prior art, the present invention creates a resource disposal method for zirconium metallurgical waste alkali liquid, by adding white carbon black to the zirconium metallurgical waste alkali liquid, reacting with the residual NaOH in the waste alkali liquid to generate water glass, and the amount of white carbon black added can be adjusted as needed, so that the newly generated water glass can be used for different purposes. High modulus water glass can be used for mineral flotation, and low modulus water glass can be used in the construction industry or other industries.

[0034] The reaction between the main components in zirconium metallurgical waste alkali liquor and white carbon black has the following equation:

[0035] 2NaOH+mSiO2→Na2O·mSiO2+H2O (4)

[0036] Na2SiO3+mSiO2→Na2O·(m+1)SiO2 (5)

[0037] The m in the reaction equation (4) and the m+1 in the equation (5) are called moduli and can be non-integers.

[0038] The present invention provides a method for resource disposal of zirconium metallurgical waste alkali liquor, and the specific operation is as follows:

[0039] Step 1: Chemical analysis of the main components in zirconium metallurgical waste lye

[0040] Sampling is performed to conduct chemical analysis on the main components in zirconium metallurgical waste alkali liquor to provide a basis for theoretical calculation of the amount of white carbon black added. The main contents of OH-, Na2O and SiO2 are analyzed, and the analysis report is mass / volume concentration in g / L.

[0041] Step 2: Calculate the amount of white carbon black added

[0042] The chemical analysis results of the contents of the main components of the zirconium metallurgical waste alkali solution in step 1, OH-, Na2O and SiO2, are converted into molar concentrations in mol / L, and the amount of white carbon black added is calculated based on the reaction equations (4) and (5) and the modulus of the desired product (water glass). If the reaction product is used for mineral processing, a higher modulus (2.5 to 3.5) is usually required; other industries have different requirements for modulus, and the amount of white carbon black added can be flexibly adjusted according to the requirements of different industries for modulus.

[0043] Step 3: Add zirconium metallurgical waste alkali liquor into a stirred reaction vessel

[0044] According to the volume of the reaction container, add an appropriate amount of zirconium metallurgical alkaline waste liquid into the stirring reaction container, start stirring, heat and keep it sealed to prevent carbon dioxide in the air from participating in the reaction.

[0045] Step 4: Add white carbon black for reaction

[0046] Add white carbon black at a certain temperature. The amount of white carbon black added can be calculated according to step 2. Add white carbon black gradually in appropriate amounts to prevent the solution from being too viscous and affecting the stirring effect, and to ensure sufficient contact and fluidity of the reactants. Stir for a certain period of time under closed conditions to allow the reaction to proceed completely.

[0047] Step 5: Release the complete reaction product

[0048] After the reaction is complete, turn off the heating device, lower the reaction temperature, and after cooling to room temperature, release and can the complete reaction product (i.e., water glass).

[0049] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0050] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0051] A mine in Inner Mongolia Autonomous Region is a polymetallic ore containing rare earth, niobium, zirconium and other useful elements. A high-grade zirconium concentrate can be obtained through ore dressing. The rare earth minerals in the ore are mainly recovered by strong magnetic flotation. Water glass needs to be added during the flotation process to inhibit other gangue minerals. The decomposition process of the zirconium concentrate will produce zirconium metallurgical waste alkali liquid. The water glass produced by the resource disposal of the zirconium metallurgical waste alkali liquid of the present invention is used for the flotation recovery of rare earth minerals in the ore. Other conditions are fixed unchanged, and only the water glass modulus is changed. Better flotation technical indicators can be obtained under a higher water glass modulus. It not only saves the purchase and transportation costs of water glass, but also disposes of zirconium metallurgical waste liquid, achieving the effect of killing two birds with one stone.

[0052] Chemical analysis results of zirconium metallurgical waste alkali solution used in the embodiment of the present invention: Na2O 2.1mol / L, SiO20.15 mol / L, OH-3.5mol / L, CO3 2- 0.20mol / L.

[0053] Example 1

[0054] Take 120mL of zirconium metallurgical waste alkali liquid, add 30g of white carbon black under stirring temperature of 27℃ and stirring speed of 500r / min, stir for 10 hours, and the modulus of the generated water glass is 1.97 after chemical analysis. The generated water glass is used for rare earth mineral flotation. Under the condition of 2kg / t, the flotation concentrate yield is 36.8%, the rare earth grade of concentrate REO is 5.02%, and the operation recovery rate is 74.64%.

[0055] Embodiment 2,

[0056] Take 120mL of zirconium metallurgical waste alkali liquid, add 40g of white carbon black under stirring temperature of 70℃ and speed of 500r / min, stir for 1 hour, and the generated water glass has a modulus of 2.20 after chemical analysis. The generated water glass is used for rare earth mineral flotation. Under the condition of 2kg / t, the obtained flotation concentrate yield is 25.65%, the concentrate rare earth grade REO is 6.63%, and the operation recovery rate is 68.72%.

[0057] Embodiment 3,

[0058] Take 120mL of zirconium metallurgical waste alkali liquid, add 50g of white carbon black under stirring temperature of 70℃ and speed of 500r / min, stir for 1 hour, and the modulus of the generated water glass is 3.03 after chemical analysis. The generated water glass is used for rare earth mineral flotation. Under the condition of 2kg / t, the obtained flotation concentrate yield is 9.29%, the concentrate rare earth grade REO is 9.29%, and the operation recovery rate is 53.02%.

[0059] Embodiment 4,

[0060] Take 120mL of zirconium metallurgical waste alkali liquid, add 55g of white carbon black under stirring temperature of 70℃ and speed of 500r / min, stir for 1 hour, and the modulus of the generated water glass is 3.54 after chemical analysis. The generated water glass is used for rare earth mineral flotation. Under the condition of 2kg / t, the flotation concentrate yield is 9.62%, the rare earth grade of concentrate REO is 11.56%, and the operation recovery rate is 44.91%.

[0061] Comparing the result data of Examples 1-4, it can be seen that water glass with a large modulus is beneficial to the improvement of the grade of rare earth flotation concentrate. The main function of water glass is to inhibit other gangue minerals in the process of flotation of rare earth minerals. The results of Examples 1-4 show that water glass with a high modulus has a stronger inhibitory effect. The yield of rare earth flotation concentrate decreases with the increase of modulus, indicating that most minerals are inhibited, thereby improving the grade of rare earth concentrate.

[0062] Embodiment 5,

[0063] The modulus of commercial water glass is 3.57. When commercial water glass is used for rare earth mineral flotation, the flotation concentrate yield is 9.58%, the rare earth grade REO of the concentrate is 11.44%, and the operation recovery rate is 44.28% under the condition of 2kg / t.

[0064] By comparing the results of Examples 4 and 5, it can be seen that the water glass prepared by the method of the present invention has the same function and effect as commercially available water glass in the flotation of rare earth minerals, and the rare earth flotation technical indicators obtained are similar.

[0065] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for recycling waste alkali liquor from zirconium metallurgy, characterized in that: The following steps are involved: Step 1: OH in zirconium metallurgical waste alkali liquor - , Na2O and SiO2 contents were chemically analyzed; Step 2, calculating the amount of white carbon black added according to the reaction equations (4) and (5) of the main components in the zirconium metallurgical waste alkali solution and white carbon black and the modulus of the water glass to be prepared; 2NaOH+mSiO2→Na2O·mSiO2+H2O (4); Na2SiO3+mSiO2→Na2O·(m+1)SiO2 (5); In reaction equations (4) and (5), m and m+1 are the moduli of water glass; Step 3, adding white carbon black to the zirconium metallurgical waste alkali solution under closed and stirring conditions to react and obtain water glass.

2. The method for recycling zirconium metallurgical waste alkali liquor according to claim 1, characterized in that: In step 3, the reaction temperature is 15-90°C.

3. The method for recycling zirconium metallurgical waste alkali liquor according to claim 1, characterized in that: In step 3, the reaction time is 10 minutes to 10 hours.

4. The method for recycling zirconium metallurgical waste alkali liquor according to claim 1, characterized in that: In step 3, the stirring speed is 50-5000r / min.

5. The method for recycling zirconium metallurgical waste alkali liquor according to claim 1, characterized in that: In step 3, the modulus of the water glass is 1.5-3.

6.

6. The method for recycling zirconium metallurgical waste alkali liquor according to claim 1, characterized in that: After step 3, the method further includes the step of using the prepared water glass to carry out floatation of rare earth minerals.

7. The method for recycling zirconium metallurgical waste alkali liquor according to claim 6, characterized in that: When rare earth minerals are flotated, the amount of water glass added is 2 kg / t of rare earth minerals.