Preparation method of zirconium oxychloride

Abstract

This invention belongs to the field of zirconium oxychloride preparation technology, specifically relating to a method for preparing zirconium oxychloride. The method comprises the following steps: (1) acid leaching of waste fused zirconium corundum brick powder; (2) alkali fusion roasting of filter residue; (3) hot water leaching and hydrochloric acid reflux; (4) purification treatment; and (5) post-treatment. The method for preparing zirconium oxychloride described in this invention uses waste fused zirconium corundum brick powder as raw material, solving the solid waste disposal problem of waste fused zirconium corundum bricks from decommissioned glass kilns, achieving efficient resource recycling, partially replacing non-renewable zircon sand raw materials, reducing production costs, and obtaining high-purity zirconium oxychloride through acid leaching, alkali fusion, hot water leaching and hydrochloric acid reflux conversion, purification, and post-treatment.

Description

Technical Field

[0001] This invention belongs to the field of zirconium oxychloride preparation technology, specifically relating to a method for preparing zirconium oxychloride. Background Technology

[0002] Zirconium oxychloride, industrially known as zirconium dichloride octahydrate (zirconium oxychloride), is also called zirconyl chloride, and commonly known as zirconium chloride. Zirconium oxychloride has a wide range of applications. Besides being used as a raw material for mordant dyes and as an additive in products such as color fixatives, deodorizers, and flame retardants, it can also be used as a stabilizer for soil in strata and as a coagulant for industrial wastewater treatment. The most important use of zirconium oxychloride is as an intermediate raw material for further processing. Direct calcination of zirconium oxychloride can produce stabilized and semi-stabilized zirconium oxide. Zirconium oxychloride can also be used to produce zirconium-containing chemicals such as zirconium carbonate, zirconium sulfate, and zirconium hydroxide, which have a wide range of applications.

[0003] The two-acid-two-alkali method involves decomposing zircon sand with alkali, washing it with water, leaching it with sulfuric acid, precipitating it with ammonia, washing away the sulfate ions, dissolving it with hydrochloric acid, and evaporating to crystallize, thus producing zirconium oxychloride. This process has two steps: sulfate washing and ammonia precipitation, making it lengthy and resulting in low recovery rates. The one-acid-one-alkali method first melts solid alkali in a cast iron pot. Once the temperature reaches 600-700℃, powdered zircon concentrate is added to the molten solid alkali to react and produce Na₂ZrO₃ and Na₄SiO₄. After separation and crystallization, zirconium oxychloride is obtained, and calcination yields zirconium oxide. This process is characterized by high energy consumption and heavy pollution, especially the crystallization process, which is carried out under high-concentration hydrochloric acid. Improper crystallization control may require multiple crystallizations, and subsequent washing is difficult, acid consumption is high, and acid mist treatment is challenging, increasing environmental impact. Furthermore, the waste acid from the mother liquor after crystallization contains a large amount of valuable elements such as zirconium and rare earth elements. During the neutralization process, a large amount of neutralization residue is formed, which, according to environmental protection requirements, needs to be stockpiled and disposed of, resulting in significant environmental pressure and resource waste. The main principle of the lime method is that at a temperature of 1400-1500℃, zircon and lime react rapidly to produce calcium zirconate and calcium silicate. Soluble impurities are washed out, and the resulting water is transferred to the raw material. The washed material is then acid-leached with hydrochloric acid, concentrated, crystallized, and recrystallized to obtain the finished product, zirconium oxychloride octahydrate. Because the purity of lime is not as high as that of solid alkali, and users have high requirements for product quality, this method is rarely used. Moreover, all the above methods use zircon sand as raw material, which is a non-renewable mineral resource and is relatively expensive.

[0004] Therefore, it is necessary to explore a novel method for preparing zirconium oxychloride. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing zirconium oxychloride, which yields zirconium oxychloride with high purity.

[0006] The method for preparing zirconium oxychloride according to the present invention comprises the following steps: (1) Add hydrochloric acid solution to waste fused zirconium corundum brick powder, stir and leach, filter, wash the resulting filter residue with deionized water until neutral, and then dry it; (2) Mix the dried filter residue, sodium carbonate and borax from step (1) and place them in a muffle furnace to calcine at 700°C for 35-40 min. Then take out the pre-calcined material and cool it to 140-150°C. Add solid sodium hydroxide and mix well. Then continue to place it in a muffle furnace to calcine at 700°C for 2.0-2.2 h. Finally, cool it to room temperature with the furnace and take out the calcined product. (3) The calcined product is added to hot water for leaching reaction, then filtered while hot, hydrochloric acid is added to the obtained filter residue for stirring and reflux reaction, and finally filtered again to prepare crude zirconium oxychloride solution. (4) The crude zirconium oxychloride solution obtained in step (3) is purified to prepare a high-purity zirconium oxychloride solution; (5) The high-purity zirconium oxychloride solution obtained in step (4) is subjected to vacuum distillation, crystallization, centrifugation and drying to prepare zirconium oxychloride.

[0007] In step (1), the glass material adhering to the surface of the waste electrofused zirconia-corundum bricks in the glass furnace is removed, and the bricks are cracked by quenching. Then, they are crushed, ground, and sieved to obtain powder with a particle size of <0.088mm. The chemical composition of the waste electrofused zirconia-corundum brick powder is as follows: Al2O3 39.98-41.09%, ZrO2 40.66-41.75%, SiO2 14.61-15.07%, MgO 0.89-1.02%, Fe2O3 0.79-0.83%, CaO 0.32-0.48%, Na2O 1.01-1.21%.

[0008] In step (1), the mass concentration of hydrochloric acid is 15-17%, and the mass-volume ratio of waste fused zirconia corundum brick powder to hydrochloric acid is 1:2.7, with units of g / mL.

[0009] In step (1), the stirring and leaching temperature is 60℃, the stirring and leaching time is 1-1.2h, and the stirring speed is 200r / min.

[0010] In step (1), the drying temperature is 70-75℃, the drying time is 3.5h, and the drying vacuum degree is -0.08MPa.

[0011] In step (2), the mass ratio of sodium hydroxide solid to sodium carbonate is 2-2.1:1.

[0012] The mass ratio of sodium carbonate and sodium hydroxide solids in step (2) to the mass ratio of the dried filter residue in step (1) is 1:1.0-1.1.

[0013] In step (2), the mass of borax accounts for 5% of the total mass of sodium carbonate, sodium hydroxide solid, and the filter residue dried in step (1).

[0014] In step (2), a mixture of sodium carbonate solid and sodium hydroxide solid is selected as the composite alkali. Sodium carbonate plays a certain role in reducing the melting temperature of the system. At the same time, sodium carbonate has higher reactivity with alumina and silicon dioxide than zirconium oxide, which can reduce the side reaction between zirconium oxide and excess alkali, thereby reducing the loss of zirconium.

[0015] In step (3), the mass-volume ratio of the roasted product to the hot water is 1:5.5, with the unit being g / mL. The temperature of the hot water is 80℃. The hot water is cooled to 80℃ after boiling before use. The leaching reaction temperature is 80℃, and the leaching reaction time is 2-2.2h.

[0016] In step (3), the filtration equipment is preheated with hot water at 85°C for 5 minutes before use.

[0017] In step (3), the mass-volume ratio of filter residue to hydrochloric acid is 1:4.0, with units of g / mL, and the mass concentration of hydrochloric acid is 32%.

[0018] In step (3), the temperature of the stirring and reflux reaction is 90℃, and the stirring and reflux reaction time is 3h.

[0019] The purification process described in step (4) consists of the following steps: ① Sodium fluorosilicate is first added to the crude zirconium oxychloride solution prepared in step (3) and stirred at room temperature, then filtered; ② Add a 10% sodium carbonate solution to the obtained filtrate to adjust the pH of the system to 3.8, then add solid sodium fluoride, stir the reaction at room temperature, and filter. ③ Add hydrochloric acid to the filtrate obtained from ② filtration to adjust the pH of the system to 1.5, add the extractant to extract, and collect the organic phase by separation; ④ Add hydrochloric acid to the organic phase for back-extraction, and the aqueous phase obtained by separation is a high-purity zirconium oxychloride solution.

[0020] In step (4) ①, the mass-to-volume ratio of sodium fluorosilicate to crude zirconium oxychloride solution is 0.02-0.03 g / L, the stirring reaction time is 30-35 min, and the stirring speed is 250 r / min.

[0021] In step (4) ②, the mass-to-volume ratio of sodium fluoride to the resulting filtrate is 0.7-0.9 g / L, the stirring reaction temperature is room temperature, the stirring reaction time is 30-35 min, and the stirring speed is 250 r / min.

[0022] In step (4) ②, solid sodium fluoride is added in three parts, each time by 1 / 3 of the total mass of solid sodium fluoride, with a 5-minute interval between each addition.

[0023] In step (4) ③, the mass concentration of hydrochloric acid is 10%, and the extractant is obtained by mixing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and kerosene at a volume ratio of 1:5.

[0024] In step (4) ③, the volume ratio of the extractant to the filtrate with the pH adjusted to 1.5 is 1:1.

[0025] The extraction temperature described in step (4) ③ is room temperature. First, stir for 20 minutes, then let stand for 30 minutes before separating the liquid.

[0026] In step (4) ④, the concentration of dilute hydrochloric acid is 2 mol / L, and the volume ratio of dilute hydrochloric acid to organic phase is 0.5:1. First, stir for 20 min, then let stand for 30 min before separating the liquid.

[0027] In step (5), the temperature of vacuum distillation is 80-83℃, the vacuum degree is -0.08MPa, and the vacuum distillation time is 2h.

[0028] In step (5), after vacuum distillation, the mixture is stirred continuously for 30 minutes at a stirring speed of 100 r / min, and then crystallization is carried out at a crystallization temperature of 25℃ and a crystallization time of 12 h.

[0029] In step (5), the centrifugation speed is 3500 r / min and the time is 12 min.

[0030] In step (5), the drying temperature is 60-63℃, the drying time is 4h, and the drying pressure is -0.08MPa.

[0031] Compared with the prior art, the present invention has the following advantages: (1) The method for preparing zirconium oxychloride described in this invention uses waste fused zirconium corundum brick powder as raw material to solve the solid waste disposal problem of waste fused zirconium corundum bricks from decommissioned glass kilns, realize efficient recycling of resources, partially replace non-renewable zircon sand raw material, reduce production costs, and obtain high-purity zirconium oxychloride through acid leaching, alkali fusion, hot water leaching and hydrochloric acid reflux conversion, purification and post-treatment.

[0032] (2) The method for preparing zirconium oxychloride described in this invention first involves a stirring leaching reaction with hydrochloric acid solution to remove soluble impurities such as Fe2O3, MgO, CaO, and Na2O from waste fused zirconium corundum brick powder; then the filter residue is melt-calcined together with sodium carbonate and sodium hydroxide solid alkali to generate water-insoluble Na2ZrO3 and water-soluble NaAlO2 and Na2SiO3, which facilitates subsequent separation; subsequently, hot water leaching is used to completely dissolve water-soluble impurities such as NaAlO2 and Na2SiO3 into the aqueous phase, while the water-insoluble Na2ZrO3 in the calcination product remains in the filter residue, achieving efficient separation of Zr from Al and Si; 32% hydrochloric acid is used to react with Na2ZrO3 in the filter residue to undergo a metathesis reaction, converting Zr from the solid phase (Na2ZrO3) into the liquid phase (ZrOCl2), forming a crude zirconium oxychloride solution; finally, after purification and post-treatment steps, high-purity zirconium oxychloride is obtained.

[0033] (3) The method for preparing zirconium oxychloride according to the present invention is carried out in four sub-steps in the purification process of step (4). First, sodium fluorosilicate is added to remove trace amounts of silicate ions that remain in the crude zirconium oxychloride solution; then sodium fluoride is added to further remove Ca. 2+ Mg 2+ Next, the pH was adjusted to 1.5, and Zr was selectively extracted using an extraction process. 4+ This achieves separation from impurity ions; finally, Zr is back-extracted using 2 mol / L hydrochloric acid to achieve separation. 4+ The solution was then transferred back into the aqueous phase to obtain a high-purity zirconium oxychloride solution. Detailed Implementation

[0034] Example 1 The method for preparing zirconium oxychloride described in Example 1 consists of the following steps: (1) Add hydrochloric acid solution to waste fused zirconium corundum brick powder, stir and leach, filter, wash the resulting filter residue with deionized water until neutral, and then dry it; (2) Mix the dried filter residue, sodium carbonate and borax from step (1), place them in a muffle furnace and calcine at 700°C for 38 min. Then take out the pre-calcined material and cool it to 145°C. Add sodium hydroxide solid and mix it. Then continue to place it in a muffle furnace and calcine at 700°C for 2.1 h. Finally, cool it to room temperature with the furnace and take out the calcined product. (3) The calcined product is added to hot water for leaching reaction, then filtered while hot, hydrochloric acid is added to the obtained filter residue for stirring and reflux reaction, and finally filtered again to prepare crude zirconium oxychloride solution. (4) The crude zirconium oxychloride solution obtained in step (3) is purified to prepare a high-purity zirconium oxychloride solution; (5) The high-purity zirconium oxychloride solution obtained in step (4) is subjected to vacuum distillation, crystallization, centrifugation and drying to prepare zirconium oxychloride.

[0035] In step (1), the glass material attached to the surface of the waste fused zirconia-corundum bricks in the glass furnace is removed, and the bricks are cracked by quenching. Then, they are crushed, ground, and sieved to obtain powder with a particle size of <0.088mm. The chemical composition of the waste fused zirconia-corundum brick powder is: Al2O3 41.07%, ZrO2 40.66%, SiO2 15.07%, MgO 0.89%, Fe2O3 0.81%, CaO 0.40%, Na2O 1.10%.

[0036] In step (1), the mass concentration of hydrochloric acid is 16%, and the mass-volume ratio of waste fused zirconia corundum brick powder to hydrochloric acid is 1:2.7, with units of g / mL.

[0037] In step (1), the stirring and leaching temperature is 60℃, the stirring and leaching time is 1.1h, and the stirring speed is 200r / min.

[0038] In step (1), the drying temperature is 73℃, the drying time is 3.5h, and the drying vacuum degree is -0.08MPa.

[0039] In step (2), the mass ratio of sodium hydroxide solid to sodium carbonate is 2.05:1.

[0040] The mass ratio of sodium carbonate and sodium hydroxide solids in step (2) to the mass ratio of the dried filter residue in step (1) is 1:1.05.

[0041] In step (2), the mass of borax accounts for 5% of the total mass of sodium carbonate, sodium hydroxide solid, and the filter residue dried in step (1).

[0042] In step (2), a mixture of sodium carbonate solid and sodium hydroxide solid is selected as the composite alkali. Sodium carbonate plays a certain role in fluxing and reducing the melting temperature of the system. At the same time, sodium carbonate has a higher reactivity with alumina and silicon dioxide than zirconium oxide, which can reduce the side reaction between zirconium oxide and excess alkali, thereby reducing the loss of zirconium.

[0043] In step (3), the mass-volume ratio of the roasted product to the hot water is 1:5.5, with units of g / mL. The temperature of the hot water is 80℃. The hot water is cooled to 80℃ after boiling before use. The leaching reaction temperature is 80℃, and the leaching reaction time is 2.1h.

[0044] In step (3), the filtration equipment is preheated with hot water at 85°C for 5 minutes before use.

[0045] In step (3), the mass-volume ratio of filter residue to hydrochloric acid is 1:4.0, with units of g / mL, and the mass concentration of hydrochloric acid is 32%.

[0046] In step (3), the temperature of the stirring and reflux reaction is 90℃, and the stirring and reflux reaction time is 3h.

[0047] The purification process described in step (4) consists of the following steps: ① Sodium fluorosilicate is first added to the crude zirconium oxychloride solution prepared in step (3) and stirred at room temperature, then filtered; ② Add a 10% sodium carbonate solution to the obtained filtrate to adjust the pH of the system to 3.8, then add solid sodium fluoride, stir the reaction at room temperature, and filter. ③ Add hydrochloric acid to the filtrate obtained from ② filtration to adjust the pH of the system to 1.5, add the extractant to extract, and collect the organic phase by separation; ④ Add hydrochloric acid to the organic phase for back-extraction, and the aqueous phase obtained by separation is a high-purity zirconium oxychloride solution.

[0048] In step (4) ①, the mass-to-volume ratio of sodium fluorosilicate to crude zirconium oxychloride solution is 0.025 g / L, the stirring reaction time is 33 min, and the stirring speed is 250 r / min.

[0049] In step (4) ②, the mass-to-volume ratio of sodium fluoride to the obtained filtrate is 0.7 g / L, the stirring reaction temperature is room temperature, the stirring reaction time is 33 min, and the stirring speed is 250 r / min.

[0050] In step (4) ②, solid sodium fluoride is added in three parts, each time by 1 / 3 of the total mass of solid sodium fluoride, with a 5-minute interval between each addition.

[0051] In step (4) ③, the mass concentration of hydrochloric acid is 10%, and the extractant is obtained by mixing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and kerosene at a volume ratio of 1:5.

[0052] In step (4) ③, the volume ratio of the extractant to the filtrate with the pH adjusted to 1.5 is 1:1.

[0053] The extraction temperature described in step (4) ③ is room temperature. First, stir for 20 minutes, then let stand for 30 minutes before separating the liquid.

[0054] In step (4) ④, the concentration of dilute hydrochloric acid is 2 mol / L, and the volume ratio of dilute hydrochloric acid to organic phase is 0.5:1. First, stir for 20 min, then let stand for 30 min before separating the liquid.

[0055] In step (5), the temperature of vacuum distillation is 81℃, the vacuum degree is -0.08MPa, and the vacuum distillation time is 2h.

[0056] In step (5), after vacuum distillation, the mixture is stirred continuously for 30 minutes at a stirring speed of 100 r / min, and then crystallization is carried out at a crystallization temperature of 25℃ and a crystallization time of 12 h.

[0057] In step (5), the centrifugation speed is 3500 r / min and the time is 12 min.

[0058] In step (5), the drying temperature is 61℃, the drying time is 4h, and the drying pressure is -0.08MPa.

[0059] According to the test, the zirconium content in the high-purity zirconium oxychloride prepared in Example 1 was 99.92 wt%, calculated as ZrO2.

[0060] Example 2 The method for preparing zirconium oxychloride described in Example 2 consists of the following steps: (1) Add hydrochloric acid solution to waste fused zirconium corundum brick powder, stir and leach, filter, wash the resulting filter residue with deionized water until neutral, and then dry it; (2) Mix the dried filter residue, sodium carbonate and borax from step (1), place them in a muffle furnace and calcine at 700°C for 35 min. Then take out the pre-calcined material and cool it to 140°C. Add sodium hydroxide solid and mix it. Then continue to place it in a muffle furnace and calcine at 700°C for 2.2 h. Finally, cool it to room temperature with the furnace and take out the calcined product. (3) The calcined product is added to hot water for leaching reaction, then filtered while hot, hydrochloric acid is added to the obtained filter residue for stirring and reflux reaction, and finally filtered again to prepare crude zirconium oxychloride solution. (4) The crude zirconium oxychloride solution obtained in step (3) is purified to prepare a high-purity zirconium oxychloride solution; (5) The high-purity zirconium oxychloride solution obtained in step (4) is subjected to vacuum distillation, crystallization, centrifugation and drying to prepare zirconium oxychloride.

[0061] In step (1), the glass material attached to the surface of the waste electrofused zirconia-corundum bricks in the glass furnace is removed, and the bricks are cracked by quenching. Then, they are crushed, ground, and sieved to obtain powder with a particle size of <0.088mm. The chemical composition of the waste electrofused zirconia-corundum brick powder is: Al2O3 39.98%, ZrO2 41.75%, SiO2 14.89%, MgO 1.02%, Fe2O3 0.83%, CaO 0.32%, Na2O 1.21%.

[0062] In step (1), the mass concentration of hydrochloric acid is 15%, and the mass-volume ratio of waste fused zirconia corundum brick powder to hydrochloric acid is 1:2.7, with units of g / mL.

[0063] In step (1), the stirring and leaching temperature is 60℃, the stirring and leaching time is 1.2h, and the stirring speed is 200r / min.

[0064] In step (1), the drying temperature is 70℃, the drying time is 3.5h, and the drying vacuum degree is -0.08MPa.

[0065] In step (2), the mass ratio of sodium hydroxide solid to sodium carbonate is 2.1:1.

[0066] The mass ratio of sodium carbonate and sodium hydroxide solids in step (2) to the mass ratio of the dried filter residue in step (1) is 1:1.0.

[0067] In step (2), the mass of borax accounts for 5% of the total mass of sodium carbonate, sodium hydroxide solid, and the filter residue dried in step (1).

[0068] In step (2), a mixture of sodium carbonate solid and sodium hydroxide solid is selected as the composite alkali. Sodium carbonate plays a certain role in fluxing and reducing the melting temperature of the system. At the same time, sodium carbonate has a higher reactivity with alumina and silicon dioxide than zirconium oxide, which can reduce the side reaction between zirconium oxide and excess alkali, thereby reducing the loss of zirconium.

[0069] In step (3), the mass-volume ratio of the roasted product to the hot water is 1:5.5, with units of g / mL. The temperature of the hot water is 80℃. The hot water is cooled to 80℃ after boiling before use. The leaching reaction temperature is 80℃, and the leaching reaction time is 2.2h.

[0070] In step (3), the filtration equipment is preheated with hot water at 85°C for 5 minutes before use.

[0071] In step (3), the mass-volume ratio of filter residue to hydrochloric acid is 1:4.0, with units of g / mL, and the mass concentration of hydrochloric acid is 32%.

[0072] In step (3), the temperature of the stirring and reflux reaction is 90℃, and the stirring and reflux reaction time is 3h.

[0073] The purification process described in step (4) consists of the following steps: ① Sodium fluorosilicate is first added to the crude zirconium oxychloride solution prepared in step (3) and stirred at room temperature, then filtered; ② Add a 10% sodium carbonate solution to the obtained filtrate to adjust the pH of the system to 3.8, then add solid sodium fluoride, stir the reaction at room temperature, and filter. ③ Add hydrochloric acid to the filtrate obtained from ② filtration to adjust the pH of the system to 1.5, add the extractant to extract, and collect the organic phase by separation; ④ Add hydrochloric acid to the organic phase for back-extraction, and the aqueous phase obtained by separation is a high-purity zirconium oxychloride solution.

[0074] In step (4) ①, the mass-to-volume ratio of sodium fluorosilicate to crude zirconium oxychloride solution is 0.03 g / L, the stirring reaction time is 30 min, and the stirring speed is 250 r / min.

[0075] In step (4) ②, the mass-to-volume ratio of sodium fluoride to the obtained filtrate is 0.8 g / L, the stirring reaction temperature is room temperature, the stirring reaction time is 30 min, and the stirring speed is 250 r / min.

[0076] In step (4) ②, solid sodium fluoride is added in three parts, each time by 1 / 3 of the total mass of solid sodium fluoride, with a 5-minute interval between each addition.

[0077] In step (4) ③, the mass concentration of hydrochloric acid is 10%, and the extractant is obtained by mixing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and kerosene at a volume ratio of 1:5.

[0078] In step (4) ③, the volume ratio of the extractant to the filtrate with the pH adjusted to 1.5 is 1:1.

[0079] The extraction temperature described in step (4) ③ is room temperature. First, stir for 20 minutes, then let stand for 30 minutes before separating the liquid.

[0080] In step (4) ④, the concentration of dilute hydrochloric acid is 2 mol / L, and the volume ratio of dilute hydrochloric acid to organic phase is 0.5:1. First, stir for 20 min, then let stand for 30 min before separating the liquid.

[0081] In step (5), the temperature of vacuum distillation is 83℃, the vacuum degree is -0.08MPa, and the vacuum distillation time is 2h.

[0082] In step (5), after vacuum distillation, the mixture is stirred continuously for 30 minutes at a stirring speed of 100 r / min, and then crystallization is carried out at a crystallization temperature of 25℃ and a crystallization time of 12 h.

[0083] In step (5), the centrifugation speed is 3500 r / min and the time is 12 min.

[0084] In step (5), the drying temperature is 63℃, the drying time is 4h, and the drying pressure is -0.08MPa.

[0085] According to the test, the zirconium content in the high-purity zirconium oxychloride prepared in Example 2 was 99.95 wt%, calculated as ZrO2.

[0086] Example 3 The method for preparing zirconium oxychloride described in Example 3 consists of the following steps: (1) Add hydrochloric acid solution to waste fused zirconium corundum brick powder, stir and leach, filter, wash the resulting filter residue with deionized water until neutral, and then dry it; (2) Mix the dried filter residue, sodium carbonate and borax from step (1), place them in a muffle furnace and calcine at 700°C for 40 min. Then take out the pre-calcined material and cool it to 150°C. Add sodium hydroxide solid and mix it. Then continue to place it in a muffle furnace and calcine at 700°C for 2.0 h. Finally, cool it to room temperature with the furnace and take out the calcined product. (3) The calcined product is added to hot water for leaching reaction, then filtered while hot, hydrochloric acid is added to the obtained filter residue for stirring and reflux reaction, and finally filtered again to prepare crude zirconium oxychloride solution. (4) The crude zirconium oxychloride solution obtained in step (3) is purified to prepare a high-purity zirconium oxychloride solution; (5) The high-purity zirconium oxychloride solution obtained in step (4) is subjected to vacuum distillation, crystallization, centrifugation and drying to prepare zirconium oxychloride.

[0087] In step (1), the glass material attached to the surface of the waste electrofused zirconia-corundum bricks in the glass furnace is removed, and the bricks are cracked by quenching. Then, they are crushed, ground, and sieved to obtain powder with a particle size of <0.088mm. The chemical composition of the waste electrofused zirconia-corundum brick powder is: Al2O3 41.09%, ZrO2 41.03%, SiO2 14.61%, MgO 0.99%, Fe2O3 0.79%, CaO 0.48%, Na2O 1.01%.

[0088] In step (1), the mass concentration of hydrochloric acid is 17%, and the mass-volume ratio of waste fused zirconia corundum brick powder to hydrochloric acid is 1:2.7, with units of g / mL.

[0089] In step (1), the stirring and leaching temperature is 60℃, the stirring and leaching time is 1h, and the stirring speed is 200r / min.

[0090] In step (1), the drying temperature is 75℃, the drying time is 3.5h, and the drying vacuum degree is -0.08MPa.

[0091] In step (2), the mass ratio of sodium hydroxide solid to sodium carbonate is 2.0:1.

[0092] The mass ratio of sodium carbonate and sodium hydroxide solids in step (2) to the mass ratio of the dried filter residue in step (1) is 1:1.1.

[0093] In step (2), the mass of borax accounts for 5% of the total mass of sodium carbonate, sodium hydroxide solid, and the filter residue dried in step (1).

[0094] In step (2), a mixture of sodium carbonate solid and sodium hydroxide solid is selected as the composite alkali. Sodium carbonate plays a certain role in fluxing and reducing the melting temperature of the system. At the same time, sodium carbonate has a higher reactivity with alumina and silicon dioxide than zirconium oxide, which can reduce the side reaction between zirconium oxide and excess alkali, thereby reducing the loss of zirconium.

[0095] In step (3), the mass-volume ratio of the roasted product to the hot water is 1:5.5, with units of g / mL. The temperature of the hot water is 80℃. The hot water is cooled to 80℃ after boiling before use. The leaching reaction temperature is 80℃, and the leaching reaction time is 2h.

[0096] In step (3), the filtration equipment is preheated with hot water at 85°C for 5 minutes before use.

[0097] In step (3), the mass-volume ratio of filter residue to hydrochloric acid is 1:4.0, with units of g / mL, and the mass concentration of hydrochloric acid is 32%.

[0098] In step (3), the temperature of the stirring and reflux reaction is 90℃, and the stirring and reflux reaction time is 3h.

[0099] The purification process described in step (4) consists of the following steps: ① Sodium fluorosilicate is first added to the crude zirconium oxychloride solution prepared in step (3) and stirred at room temperature, then filtered; ② Add a 10% sodium carbonate solution to the obtained filtrate to adjust the pH of the system to 3.8, then add solid sodium fluoride, stir the reaction at room temperature, and filter. ③ Add hydrochloric acid to the filtrate obtained from ② filtration to adjust the pH of the system to 1.5, add the extractant to extract, and collect the organic phase by separation; ④ Add hydrochloric acid to the organic phase for back-extraction, and the aqueous phase obtained by separation is a high-purity zirconium oxychloride solution.

[0100] In step (4) ①, the mass-to-volume ratio of sodium fluorosilicate to crude zirconium oxychloride solution is 0.02 g / L, the stirring reaction time is 35 min, and the stirring speed is 250 r / min.

[0101] In step (4) ②, the mass-to-volume ratio of sodium fluoride to the obtained filtrate is 0.9 g / L, the stirring reaction temperature is room temperature, the stirring reaction time is 35 min, and the stirring speed is 250 r / min.

[0102] In step (4) ②, solid sodium fluoride is added in three parts, each time by 1 / 3 of the total mass of solid sodium fluoride, with a 5-minute interval between each addition.

[0103] In step (4) ③, the mass concentration of hydrochloric acid is 10%, and the extractant is obtained by mixing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and kerosene at a volume ratio of 1:5.

[0104] In step (4) ③, the volume ratio of the extractant to the filtrate with the pH adjusted to 1.5 is 1:1.

[0105] The extraction temperature described in step (4) ③ is room temperature. First, stir for 20 minutes, then let stand for 30 minutes before separating the liquid.

[0106] In step (4) ④, the concentration of dilute hydrochloric acid is 2 mol / L, and the volume ratio of dilute hydrochloric acid to organic phase is 0.5:1. First, stir for 20 min, then let stand for 30 min before separating the liquid.

[0107] In step (5), the temperature of vacuum distillation is 80℃, the vacuum degree is -0.08MPa, and the vacuum distillation time is 2h.

[0108] In step (5), after vacuum distillation, the mixture is stirred continuously for 30 minutes at a stirring speed of 100 r / min, and then crystallization is carried out at a crystallization temperature of 25℃ and a crystallization time of 12 h.

[0109] In step (5), the centrifugation speed is 3500 r / min and the time is 12 min.

[0110] In step (5), the drying temperature is 60℃, the drying time is 4h, and the drying pressure is -0.08MPa.

[0111] According to the test, the zirconium content in the high-purity zirconium oxychloride prepared in Example 3 was 99.94 wt% (calculated as ZrO2).

[0112] Comparative Example 1 The preparation method of zirconium oxychloride described in Comparative Example 1 is the same as that in Example 1, except that the purification step (4) is omitted. The zirconium content in the high-purity zirconium oxychloride prepared in Comparative Example 1 is 99.45 wt%, calculated as ZrO2.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing zirconium oxychloride, characterized in that: It consists of the following steps: (1) Add hydrochloric acid solution to waste fused zirconium corundum brick powder, stir and leach, filter, wash the resulting filter residue with deionized water until neutral, and then dry it; (2) Mix the dried filter residue, sodium carbonate and borax from step (1) and place them in a muffle furnace to calcine at 700°C for 35-40 min. Then take out the pre-calcined material and cool it to 140-150°C. Add solid sodium hydroxide and mix well. Then continue to place it in a muffle furnace to calcine at 700°C for 2.0-2.2 h. Finally, cool it to room temperature with the furnace and take out the calcined product. (3) The calcined product is added to hot water for leaching reaction, then filtered while hot, hydrochloric acid is added to the obtained filter residue for stirring and reflux reaction, and finally filtered again to prepare crude zirconium oxychloride solution. (4) The crude zirconium oxychloride solution obtained in step (3) is purified to prepare a high-purity zirconium oxychloride solution; (5) The high-purity zirconium oxychloride solution obtained in step (4) is subjected to vacuum distillation, crystallization, centrifugation and drying to prepare zirconium oxychloride; in: In step (1), the glassy material adhering to the surface of the waste fused zirconia-corundum bricks in the glass furnace is removed. The bricks are then cracked by quenching, crushed, ground, and sieved to obtain powder with a particle size <0.088mm. The chemical composition of the waste fused zirconia-corundum brick powder is as follows: Al2O3 39.98-41.09%, ZrO2 40.66-41.75%, SiO2 14.61-15.07%, MgO 0.89-1.02%, Fe2O3 0.79-0.83%, CaO 0.32-0.48%, Na2O 1.01-1.21%. In step (1), the mass concentration of hydrochloric acid is 15-17%, and the mass-volume ratio of waste fused zirconia corundum brick powder to hydrochloric acid is 1:2.7, with units of g / mL. In step (1), the stirring and leaching temperature is 60℃, the stirring and leaching time is 1-1.2h, and the stirring speed is 200r / min; In step (1), the drying temperature is 70-75℃, the drying time is 3.5h, and the drying vacuum degree is -0.08MPa; The purification process described in step (4) consists of the following steps: ① First, add sodium fluorosilicate to the crude zirconium oxychloride solution prepared in step (3) and stir at room temperature, then filter. ② Add a 10% sodium carbonate solution to the obtained filtrate to adjust the pH of the system to 3.8, then add solid sodium fluoride, stir the reaction at room temperature, and filter. ③ Add hydrochloric acid to the filtrate obtained from ② filtration to adjust the pH of the system to 1.5, add the extractant for extraction, and collect the organic phase by separation; ④ Add hydrochloric acid to the organic phase for back-extraction, and the aqueous phase obtained by separation is a high-purity zirconium oxychloride solution.

2. The method for preparing zirconium oxychloride according to claim 1, characterized in that: In step (2), the mass ratio of solid sodium hydroxide to sodium carbonate is 2-2.1:1; The mass ratio of sodium carbonate and sodium hydroxide solids in step (2) to the mass ratio of the dried filter residue in step (1) is 1:1.0-1.1; In step (2), the mass of borax accounts for 5% of the total mass of sodium carbonate, sodium hydroxide solid, and the filter residue dried in step (1).

3. The method for preparing zirconium oxychloride according to claim 1, characterized in that: In step (3), the mass-volume ratio of the roasted product to the hot water is 1:5.5, with the unit being g / mL. The temperature of the hot water is 80℃. The hot water is cooled to 80℃ after boiling before use. The leaching reaction temperature is 80℃, and the leaching reaction time is 2-2.2h. In step (3), the mass-to-volume ratio of filter residue to hydrochloric acid is 1:4.0, with units of g / mL, and the mass concentration of hydrochloric acid is 32%. In step (3), the temperature of the stirring and reflux reaction is 90℃, and the stirring and reflux reaction time is 3h.

4. The method for preparing zirconium oxychloride according to claim 1, characterized in that: [the following is a description of the method, not a direct translation] In step (4) ①, the mass-to-volume ratio of sodium fluorosilicate to crude zirconium oxychloride solution is 0.02-0.03 g / L, the stirring reaction time is 30-35 min, and the stirring speed is 250 r / min; In step (4) ②, the mass-to-volume ratio of sodium fluoride to the obtained filtrate is 0.7-0.9 g / L, the stirring reaction temperature is room temperature, the stirring reaction time is 30-35 min, and the stirring speed is 250 r / min; In step (4) ②, solid sodium fluoride is added in three parts, each time by 1 / 3 of the total mass of solid sodium fluoride, with a 5-minute interval between each addition.

5. The method for preparing zirconium oxychloride according to claim 1, characterized in that: In step (4) ③, the mass concentration of hydrochloric acid is 10%, and the extractant is obtained by mixing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and kerosene at a volume ratio of 1:

5. In step (4) ③, the volume ratio of the extractant to the filtrate with the pH adjusted to 1.5 is 1:1; The extraction temperature described in step (4) ③ is room temperature. First, stir for 20 minutes, then let stand for 30 minutes before separating the liquids. In step (4) ④, the concentration of dilute hydrochloric acid is 2 mol / L, and the volume ratio of dilute hydrochloric acid to organic phase is 0.5:

1. First, stir for 20 min, then let stand for 30 min before separating the liquid.

6. The method for preparing zirconium oxychloride according to claim 1, characterized in that: In step (5), the temperature for vacuum distillation is 80-83℃, the vacuum degree is -0.08MPa, and the vacuum distillation time is 2h. In step (5), after vacuum distillation, the mixture is stirred continuously for 30 minutes at a stirring speed of 100 r / min, and then crystallization is carried out at a crystallization temperature of 25℃ and a crystallization time of 12 h.

7. The method for preparing zirconium oxychloride according to claim 1, characterized in that: In step (5), the centrifugation speed is 3500 r / min and the time is 12 min; In step (5), the drying temperature is 60-63℃, the drying time is 4h, and the drying pressure is -0.08MPa.