A method for producing high-purity zirconia using zirconium-containing recycled material

Abstract

The present application relates to a kind of method for producing high-purity zirconia using zirconium-containing recycled material, comprising the following steps: S1 smelting: zirconium-containing recycled material is mixed with quartz sand or soda ash, the mixing ratio of quartz sand is 5-30%, the mixing ratio of soda ash is 10-40%, smelting is carried out under oxidizing atmosphere.The method for producing high-purity zirconia using zirconium-containing recycled material, the method for producing high-purity zirconia using zirconium-containing recycled material, uses zircon sand with impurity content meeting the requirements as raw material, adds smelting aid, smelting is carried out in electric arc furnace including but not limited to, is sprayed into ball, alkali solution decomposition, filter alkali, wash alkali, pickling, washing, filtration, finally through drying and is prepared ZrO2 Content≥99% zirconia powder, the present application provides a kind of green, simple, low-cost technical route for zirconium-containing recycled material, provides a kind of feasible solution for the recycling of zirconia material, with good economic benefit and social benefit.

Description

Technical Field

[0001] This invention relates to the field of high-purity zirconium oxide production technology, specifically a method for producing high-purity zirconium oxide using zirconium-containing recycled materials. Background Technology

[0002] Zirconia generally refers to zirconium dioxide, with the molecular formula ZrO2. Depending on the production process, it is divided into chemical zirconium oxide and fused zirconium oxide. The former has the advantages of low impurity content and high activity, but at the same time, the production process is complex, consumes a lot of water resources, has high overall production costs, and causes some pollution to the environment. The latter has a better overall cost advantage, but the fusion method can only reduce and separate SiO2 in zircon sand and cannot remove other impurities, so its application is limited.

[0003] Zirconia has a wide range of applications in industry, including ceramic glazes, advanced refractory materials, ceramic brake pad additives, synthetic diamonds, sponge zirconium, special ceramic products, and thermal barrier coatings. Both of the aforementioned production processes use imported high-grade zircon sand with a ZrO2 content of ≥66%. The supply chain for these processes is largely controlled by multinational corporations such as Rio Tinto, Tronox, and Eluka. Domestic companies mostly compete in the low-grade, low-value-added product market.

[0004] China is the world's largest producer and user of zirconium oxide, and also the largest exporter of zirconium materials. Every year, a large amount of zircon sand raw materials enter the country, while a significant amount of zirconium products are exported abroad, maintaining a healthy supply and demand relationship. In zirconium oxide applications, a large amount of zirconium-containing recyclables are generated annually, such as waste generated during ceramic production, abrasive materials from processing synthetic diamonds, dust generated during the production of high-grade refractory raw materials, and scrap materials generated after product application. The emergence of large quantities of zirconium-containing recyclables provides a new direction for zirconium raw materials. Against this backdrop, this invention develops a method for the valuable utilization of zirconium-containing recyclables. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for producing high-purity zirconium oxide using zirconium-containing recycled materials, which has advantages such as the ability to recover zirconium oxide with high purity.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for producing high-purity zirconium oxide using zirconium-containing recycled materials, comprising the following steps:

[0007] S1 Smelting: The zirconium-containing recycled material is mixed with quartz sand or soda ash, with the quartz sand mixing ratio being 5-30% and the soda ash mixing ratio being 10-40%. Smelting is carried out in an oxidizing atmosphere for 100-120 minutes. After smelting, the mixture is blown into balls using compressed air or a high-pressure blower.

[0008] S2 Alkali Dissolution: Spherical products are reacted with 10-30% alkali solution in a closed reaction vessel at a temperature of 100-130℃.

[0009] S3 Alkali Filtration: The above-mentioned alkali-dissolved solution is filtered by pressure filtration;

[0010] S4 Washing: The solid phase after filtration is washed with water 1-3 times to further remove dissolved impurities and alkali solution;

[0011] S5 pickling: Use dilute sulfuric acid or dilute hydrochloric acid to pickle the solid phase after the above-mentioned alkali washing.

[0012] S6 water wash: Removes soluble metal ions;

[0013] S7 Drying: Remove moisture from the solid phase to obtain zirconium oxide powder with ZrO2 content ≥99%;

[0014] The zirconium-containing recycled materials include defective or scrap zirconium oxide ceramic products, abrasive materials generated during the processing of zirconium oxide synthetic diamonds, and dust generated during the production of zirconium oxide material raw materials.

[0015] Furthermore, the aforementioned alkaline solution is an aqueous solution of NaOH or KOH.

[0016] Furthermore, the smelting equipment is a three-phase or DC electric arc furnace with a power of 800-4000W.

[0017] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0018] 1. This method for producing high-purity zirconium oxide using zirconium-containing recycled materials involves using zirconium-containing recycled materials or zircon sand with impurity content meeting requirements as raw materials, adding smelting aids, and smelting in an electric arc furnace, including but not limited to, blowing into pellets, alkali dissolution and decomposition, alkali filtration, alkali washing, acid washing, water washing, filtration, and finally drying to obtain zirconium oxide powder with a ZrO2 content ≥99%. This invention provides a green, simple, and low-cost technical route for zirconium-containing recycled materials, and provides a feasible solution for the recycling of zirconium oxide materials, with good economic and social benefits.

[0019] 2. The method for producing high-purity zirconium oxide using zirconium-containing recycled materials involves using zirconium-containing recycled materials or zircon sand with impurity content meeting the requirements as raw materials, adding smelting aids, smelting in an electric arc furnace, including but not limited to, blowing into pellets, alkali dissolution and decomposition, alkali filtration, alkali washing, acid washing, water washing, filtration, and finally drying to obtain zirconium oxide powder with ZrO2 content ≥99%. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention for producing high-purity zirconium oxide using zirconium-containing recycled materials. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1. A method for producing high-purity zirconium oxide using zirconium-containing recycled materials in this example includes the following steps:

[0023] S1 Smelting: The zirconium-containing recycled material is mixed with quartz sand or soda ash, with the quartz sand mixing ratio being 5-30% and the soda ash mixing ratio being 10-40%. Smelting is carried out in an oxidizing atmosphere for 100-120 minutes. After smelting, the mixture is blown into balls using compressed air or a high-pressure blower.

[0024] S2 Alkali Dissolution: The above-mentioned spherical product is reacted with an alkaline solution of 10-30% in a closed reaction vessel at a temperature of 100-130℃.

[0025] S3 Alkali Filtration: The above-mentioned alkali-dissolved solution is filtered by pressure filtration, and the main impurities are present in the liquid phase;

[0026] S4 Washing: The solid phase after filtration is washed with water 1-3 times to further remove dissolved impurities and alkali solution;

[0027] S5 pickling: Use dilute sulfuric acid or dilute hydrochloric acid to pickle the solid phase after the above-mentioned alkali washing.

[0028] S6 water wash: Removes soluble metal ions;

[0029] S7 Drying: Remove moisture from the solid phase to obtain zirconium oxide powder with a ZrO2 content ≥99%.

[0030] In step S1, SiO2 and ZrO2 are eutecticly melted and then rapidly cooled, resulting in SiO2 and ZrO2 intertwined and co-formed. Meanwhile, Na2CO3 at high temperatures can form corresponding salts with various zirconium oxides such as ZrO2 and SiO2, which helps with alkaline dissolution and acid washing to remove impurities.

[0031] In step S2, its main function is to remove major impurities from the material, such as SiO2, Al2O3, TiO2, etc., and the specific reactions involved are as follows:

[0032] SiO2 + OH- → SiO32- + H2O;

[0033] Al₂O₃ + OH⁻ → AlO₂⁻ + H₂O;

[0034] TiO2 + OH- → TiO32- + H2O;

[0035] Furthermore, the aforementioned alkaline solution can be an aqueous solution of NaOH or KOH.

[0036] In step S3, the main component of the solid phase is ZrO2, with a small amount of alkali-insoluble substances such as CaO and Y2O3, as well as a small amount of dissolved impurities and alkali solution.

[0037] In step S5, the main function is to neutralize excess alkali solution and remove remaining alkali-insoluble impurities. The specific reactions involved are as follows:

[0038] OH- + H+ → H2O;

[0039] CaO + H+ → Ca2++H2O;

[0040] Y₂O₃ + H⁺ → Y₃++H₂O.

[0041] The zirconium-containing recycled materials include defective or scrap zirconium oxide ceramic products, abrasive materials generated from processing zirconium oxide synthetic diamonds, dust and iron filings generated during the production of zirconium oxide raw materials, and other recycled materials that meet the above-mentioned impurity composition requirements. Some low-grade zircon sand is also applicable.

[0042] The smelting equipment is a three-phase or DC electric arc furnace with a power of 800-4000KW.

[0043] The smelting aids are quartz sand (SiO2) with a SiO2 content ≥98% and an optimal particle size of 0-1mm; and soda ash (Na2CO3).

[0044] Example 2.

[0045] The main oxide components of cutting sludge (recycled material) generated from the processing of synthetic gemstones are as follows:

[0046] SiO2: ≤0.1%, Al2O3: ≤0.8%, Fe2O3: ≤0.8%, ZrO2: 78-84%, Y2O3: 15-20%.

[0047] The amount of quartz sand used is 20% of the amount of recycled material used;

[0048] The melting was carried out using a 3200KW three-phase AC electric arc furnace with the following electrical parameters: voltage 190V, current 15000A; melting time 110-120 minutes; and compressed air was used to blow the mixture into balls.

[0049] Prepare a 25% NaOH solution, using the hollow spheres and alkali solution in a 1:2 ratio (by weight); react in a reactor at approximately 150°C for 3 hours.

[0050] After the above reaction, the alkali is filtered and washed three times. Then, an appropriate amount of 5% dilute sulfuric acid is added, and after reacting for 30 minutes, the acid is filtered and washed three times.

[0051] The filter cake after acid washing and dehydration was dried using a flash dryer to obtain high-purity zirconia powder with a particle size D50 of 3-6 μm. The main components are as follows: SiO2: 0.24%, Al2O3: 0.05%, Fe2O3: 0.08%, TiO2: 0.03%, Y2O3: 0.5%, ZrO2(+HfO2): 99.2%.

[0052] Example 3.

[0053] The main oxide composition of the zirconia ceramic structural components used, either substandard or recycled, is as follows:

[0054] SiO2: ≤0.05%, Al2O3: ≤0.4%, Fe2O3: ≤0.05%, ZrO2: 93-95%; Y2O3: 4-6%.

[0055] The amount of quartz sand used is 10% of the amount of recycled material used, and the amount of Na2CO3 used is 15% of the amount of recycled material used;

[0056] The melting was carried out using a 3200KW three-phase AC electric arc furnace. The melting electrical parameters were: voltage 210V, current 13000A; melting time 110-120 minutes; and compressed air was used to blow the mixture into balls.

[0057] Prepare a 20% NaOH solution, using the hollow spheres and alkali solution in a weight ratio of 1:2; react in a reactor at approximately 150°C for 5 hours.

[0058] After the above reaction, the alkali is filtered and washed three times. Then, an appropriate amount of 3% dilute sulfuric acid is added, and after reacting for 30 minutes, the acid is filtered and washed three times.

[0059] The filter cake after acid washing and dehydration was dried using a flash dryer to obtain high-purity zirconia powder with a particle size D50 of 5-8 μm. The main components are as follows: SiO2: 0.03%, Al2O3: 0.03%, Fe2O3: 0.03%, TiO2: 0.01%, Y2O3: 0.1%, ZrO2(+HfO2): 99.8%.

[0060] Example 4.

[0061] The main oxide components of waste zirconia foam ceramic filter sheets or similar recycled materials are as follows:

[0062] SiO2: ≤0.3%, Al2O3: ≤0.5%, Fe2O3: ≤0.08%, ZrO2: 94-96%; MgO:

[0063] 3-4%; CaO: ≤0.2%.

[0064] The amount of quartz sand used is 25% of the amount of recycled material used.

[0065] The melting was carried out using a 3200KW three-phase AC electric arc furnace. The melting parameters were: voltage 170V, current 16000A; melting time 110-120 minutes; and high-pressure air generated by a blower was used to blow the balls into pellets.

[0066] Prepare a 30% NaOH solution, using the hollow spheres and alkali solution in a 1:2 ratio (by weight); react in a reactor at approximately 150°C for 2 hours.

[0067] After the above reaction, the alkali is filtered and washed three times. Then, an appropriate amount of 3% dilute sulfuric acid is added, and after reacting for 30 minutes, the acid is filtered and washed three times.

[0068] The filter cake after acid washing and dehydration was dried using a flash dryer to obtain high-purity zirconia powder with a particle size D50 of 3-6 μm. The main components are as follows: SiO2: 0.16%, Al2O3: 0.04%, Fe2O3: 0.07%, TiO2: 0.18%, Y2O3: 0.25%, ZrO2(+HfO2): 99.7%; MgO: 0.05%.

[0069] Example 5.

[0070] Low-grade zircon sand is used as raw material, and its main components are as follows:

[0071] SiO2: 31-33%, Al2O3: ≤3%, Fe2O3: ≤0.2%, TiO2: ≤0.5%, ZrO2: 61-63%;

[0072] CaO: ≤0.5%, Y2O3: ≤0.5%.

[0073] The amount of quartz sand used is 5% of the amount of recycled material used, and the amount of Na2CO3 used is 20% of the amount of recycled material used;

[0074] The melting was carried out using a 3200KW three-phase AC electric arc furnace with the following electrical parameters: voltage 170V, current 16000A; melting time 110-120 minutes; and compressed air was used to blow the mixture into balls.

[0075] Prepare a 25% NaOH solution, using the hollow spheres and alkali solution in a 1:2 ratio (by weight); react in a reactor at approximately 150°C for 3 hours.

[0076] After the above reaction, the alkali is filtered and washed three times. Then, an appropriate amount of 5% dilute sulfuric acid is added, and after reacting for 30 minutes, the acid is filtered and washed three times.

[0077] The filter cake after acid washing and dehydration was dried using a flash dryer to obtain high-purity zirconia powder with a particle size D50 of 1-3 μm. The main components are as follows: SiO2: 0.25%, Al2O3: 0.06%, Fe2O3: 0.09%, TiO2: 0.25%, Y2O3: 0.25%, ZrO2(+HfO2): 99.0%; CaO: 0.01%.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing high-purity zirconium oxide using zirconium-containing recycled materials, characterized in that: Includes the following steps: S1 Smelting: The zirconium-containing recycled material is mixed with quartz sand or soda ash, with the quartz sand mixing ratio being 5-30% and the soda ash mixing ratio being 10-40%. Smelting is carried out in an oxidizing atmosphere for 100-120 minutes. After smelting, the mixture is blown into balls using compressed air or a high-pressure blower. S2 Alkali Dissolution: Spherical products are reacted with 10-30% alkali solution in a closed reaction vessel at a temperature of 100-130℃. S3 Alkali Filtration: The above-mentioned alkali-dissolved solution is filtered by pressure filtration; S4 Washing: The solid phase after filtration is washed with water 1-3 times to further remove dissolved impurities and alkali solution; S5 pickling: Use dilute sulfuric acid or dilute hydrochloric acid to pickle the solid phase after the above-mentioned alkali washing. S6 water wash: Removes soluble metal ions; S7 Drying: Remove moisture from the solid phase to obtain zirconium oxide powder with ZrO2 content ≥99%; The zirconium-containing recycled materials include defective or scrap zirconium oxide ceramic products, abrasive materials generated during the processing of zirconium oxide synthetic diamonds, and dust generated during the production of zirconium oxide material raw materials.

2. The method for producing high-purity zirconium oxide using zirconium-containing recycled material according to claim 1, characterized in that: The above-mentioned alkaline solution is an aqueous solution of NaOH or KOH.

3. The method for producing high-purity zirconium oxide using zirconium-containing recycled material according to claim 1, characterized in that: The smelting equipment is a three-phase or DC electric arc furnace with a power of 800-4000W.

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