Method and device for preparing high-purity antimony trioxide

Abstract

The invention discloses a method and device for preparing high-purity antimony trioxide, according to the preparation method of the high-purity antimony trioxide, a micro-nano bubble multi-blowing method is combined with a graded filtration method, the arsenic content can be reduced to 0.1 ppm or below through treatment of conventional reagents such as hydrogen sulfide and ammonia water, and the method has extremely high impurity removal and purification efficiency; the high-purity antimony trioxide can be efficiently obtained, and a new choice is provided for industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of chemical purification, in particular to a method and a device for preparing high-purity antimony trioxide. Background Art

[0002] Antimony trioxide is an inorganic compound with the chemical formula Sb2O3. The natural product is called antimony flower, commonly known as antimony white, which is a white crystalline powder with a melting point of 655℃ and a boiling point of 1550℃. It is soluble in concentrated hydrochloric acid, sulfuric acid, alkaline solution and hot tartaric acid solution, and slightly soluble in water, dilute nitric acid and dilute sulfuric acid. High-purity antimony trioxide has unique physical and chemical properties and is widely used in many fields, such as being used as a catalyst with high surface activity, a clarifier for television glass and refined engineering materials. It can also be used as a raw material to prepare high-purity metal ladders, and has become an indispensable new material in the field of high technology.

[0003] As and Sb both belong to the VA group and have similar physical and chemical properties. They are difficult to separate, which leads to a high arsenic content in antimony trioxide products, which is not conducive to further improving its purity and limits its scope of application. Therefore, it is necessary to develop a technology to remove the key impurity arsenic in antimony trioxide. The highest purity of antimony trioxide in the current industry standard is 99.9%, and its arsenic content still contains 40ppm, which is extremely unfavorable for the subsequent use of distillation, zone melting and other processes to prepare antimony-related ultra-high purity products, and must be removed and controlled. The conventional acid method, alkali method, chlorination method, distillation method and other arsenic removal processes currently used in antimony-related products mainly focus on the removal of constant arsenic impurities, and generally remove them to the order of tens to hundreds of ppm, and it is difficult to remove trace arsenic impurities of the order of tens of ppm.

[0004] Therefore, it is necessary to propose a method and device for preparing high-purity antimony trioxide, efficiently remove trace impurities including arsenic, and improve the quality of the product to meet industrial needs. Summary of the invention

[0005] The present invention provides a method and device for preparing high-purity antimony trioxide, so as to achieve efficient removal of trace impurities including arsenic, improve product quality and meet industrial requirements.

[0006] In view of this, the scheme of the present invention is:

[0007] A method for preparing high-purity antimony trioxide, comprising the steps of:

[0008] a) adding hydrochloric acid to 1 kg of 3N antimony oxide to dissolve it, and filtering to obtain filtrate 1;

[0009] b) slowly introducing micro-nano bubbles 1 into filtrate 1 from bottom to top, and filtering to obtain filtrate 2;

[0010] c) slowly introducing micro-nano bubbles 2 into the filtrate 2 from bottom to top, and filtering to obtain a filtrate 3;

[0011] d) adding ammonia water to the filtrate 3 to precipitate antimony, filtering to obtain wet antimony trioxide, washing the precipitate with ammonia water and deionized water in sequence, and drying to obtain high-purity antimony trioxide;

[0012] The introduction time of the micro-nano bubble 1 and the micro-nano bubble 2 is 3-60 minutes, and contains inert gas and 0.5-10L of hydrogen sulfide.

[0013] Furthermore, the size of the micro-nano bubble 1 and / or the micro-nano bubble 2 is 100 nm to 100 μm.

[0014] Furthermore, the flow rate of the micro-nano bubble 1 and / or micro-nano bubble 2 is 0.1-5 L / min.

[0015] Furthermore, the volume proportion of the inert gas in the micro-nano bubble 1 is 10-50%; and / or the volume proportion of the inert gas in the micro-nano bubble 2 is 10-30%.

[0016] Furthermore, in step a), the hydrochloric acid concentration is 3-12 mol / L and the volume is 3-9 L.

[0017] Furthermore, in step d), the concentration of ammonia water used in the antimony precipitation process is 25-28%, and the amount used is 6 times the volume of hydrochloric acid in step a).

[0018] Furthermore, in step d), the drying temperature is 70-200° C. and the drying time is 2-20 h.

[0019] Furthermore, in steps a) to d), the filtration process uses filter media with filter diameters of 1 μm, 0.5 μm, 0.2 μm and 0.1 μm respectively.

[0020] Another object of the present invention is to provide a device used in the above-mentioned method for preparing high-purity antimony trioxide, the device comprising a tank body, the tank body is divided by four partitions to form a dissolution zone, a first impurity removal zone, a second impurity removal zone, a precipitation water washing zone and a waste liquid zone arranged adjacent to each other on the left and right; each of the partitions is arranged to be liftable, and a filter plate is arranged on the right side of each partition;

[0021] An air inlet pipe 1 and an air inlet pipe 2 are respectively provided at the bottom of the impurity removal area 1 and the impurity removal area 2, and both are connected to the micro-nano bubble generator.

[0022] Furthermore, an exhaust pipe is provided at the top of at least one of the dissolution zone, the impurity removal zone 1, the impurity removal zone 2, and the precipitation water washing zone;

[0023] And / or, a stirrer is provided in the dissolution zone and the precipitation water washing zone;

[0024] And / or, a waste water pipe is provided at the bottom of the waste liquid area.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The method for preparing high-purity antimony trioxide of the present invention uses a micro-nano bubble multiple blowing method combined with a graded filtration method, and can reduce the arsenic content to below 0.1 ppm by treating with conventional reagents such as hydrogen sulfide and ammonia water. It has extremely high impurity removal and purification efficiency, can efficiently obtain high-purity antimony trioxide, and provides a new option for industrial application.

[0027] The high-purity antimony trioxide preparation device of the present invention has a simple structure and strong operability; the partition is used to separate multiple functional areas, and the lifting and lowering of the partition combined with multiple filter plates realizes the flow of materials in adjacent functional areas, thereby realizing continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the device for preparing high-purity antimony trioxide according to the present invention.

[0029] Figure 1 The reference numerals in the drawings are:

[0030] 1. Dissolution zone; 2. Impurity removal zone 1; 3. Impurity removal zone 2; 4. Sedimentation water washing zone; 5. Waste liquid zone; 11. Filter plate 1; 21. Filter plate 2; 31. Filter plate 3; 41. Filter plate 4; 100. Tank body; 200. Partition plate; L1. Liquid inlet pipe; L2. Air inlet pipe 1; L3. Air inlet pipe 2; L4. Exhaust pipe; L5. Waste liquid pipe; M1. Agitator. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with the preferred embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the first embodiment, if Figure 1 As shown, a preparation device of high-purity antimony trioxide is provided, comprising a tank body 100, wherein the tank body 100 is divided by four partitions 200 to form a dissolution zone 1, a first impurity removal zone 2, a second impurity removal zone 3, a precipitation water washing zone 4 and a waste liquid zone 5 which are arranged adjacent to each other on the left and right; each of the partitions 100 is arranged to be liftable, and a filter plate is arranged on the right side of each partition 100; wherein:

[0033] The upper part of the dissolution zone 1 is connected with a liquid inlet pipe L1 for feeding hydrochloric acid solution; the bottoms of the impurity removal zone 1 2 and the impurity removal zone 2 3 are respectively provided with an air inlet pipe 1 L2 and an air inlet pipe 2 L3, both of which are connected to the micro-nano bubble generator; the dissolution zone 1, the impurity removal zone 1 2, the impurity removal zone 2 3, and the precipitation water washing zone 4 are respectively provided with a filter plate 1 11, a filter plate 2 21, a filter plate 3 31 and a filter plate 4 41 located on the right side of the corresponding partition 100; the bottom of the waste liquid zone 5 is provided with a waste liquid pipe L5.

[0034] In the above embodiment, when preparing high-purity antimony trioxide, a measured amount of 3N antimony trioxide is added to the dissolution zone 1, and a hydrochloric acid solution is added from the liquid inlet pipe L1 to dissolve the antimony trioxide to obtain an antimony chloride solution. After sufficient dissolution, the partition 200 on the right side of the dissolution zone 1 is lifted, and the antimony chloride solution enters the impurity removal zone 2 through the filter plate 11. In the impurity removal zone 2, a mixed gas micro-nano bubble 1 containing an inert gas and hydrogen sulfide gas is introduced from the bottom along the inlet pipe 1 L2, and a bubble layer is formed in the antimony chloride solution from bottom to top to remove impurities in the antimony chloride; similarly, after the mixed gas micro-nano bubble is introduced, the partition 200 on the right side is started, and the antimony chloride solution enters the impurity removal zone 2 3 through the filter plate 2 21. In the same manner as the impurity removal zone 1 2, in the impurity removal zone 2 3, a mixed gas micro-nano bubble 2 containing an inert gas and hydrogen sulfide gas is introduced from the bottom along the inlet pipe 2 L3, and a bubble layer is formed in the solution from bottom to top to further remove impurities in the antimony chloride. After the mixed gas micro-nano bubble is introduced, the partition 200 on the right is started, and the antimony chloride solution enters the precipitation adsorption zone 4 through the filter plate 3 31. At this time, ammonia water is continuously added to the precipitation adsorption zone 4 to precipitate antimony. When no more precipitation is precipitated, the addition of ammonia water is stopped, and the partition 200 on the right side of the precipitation adsorption zone 4 is lifted. The precipitate is filtered and intercepted by the filter plate 4 41 and is placed in the precipitation adsorption zone 4. The precipitate is washed with ammonia water and deionized water respectively. Finally, the precipitate is taken out and dried to obtain high-purity antimony trioxide.

[0035] In the above embodiment, the arsenic content can be reduced to below 0.1 ppm by multiple micro-nano bubble injection combined with graded filtration using conventional reagents such as hydrogen sulfide and ammonia water. This has extremely high impurity removal and purification efficiency, and can efficiently obtain high-purity antimony trioxide, providing a new option for industrial applications.

[0036] In a preferred embodiment, the micro-nano bubble generator uses a common cyclonic gas-liquid mixing type micro-nano bubble generator, and its principle is: hydrogen sulfide is liquefied into a liquid state under a certain pressure and then mixed with an inert gas, and the gas-liquid mixed fluid entering the generator rotates at a high speed under pressure, and forms a negative pressure shaft in the middle of the generator, and the suction of the negative pressure shaft can be used to concentrate the inert gas mixed in the liquid hydrogen sulfide on the negative pressure shaft, and when the high-speed rotating liquid and gas are ejected from the ejection port under appropriate pressure, a large number of micron and nanometer bubbles are generated. The size of the ejected bubble can be adjusted according to the pressure parameters of the generator.

[0037] In a preferred embodiment, the partition 200 can be made of acid and alkali resistant materials to prevent corrosion and impurities from being introduced during the impurity removal process, preferably a high molecular polymer such as PP material. The filter plate 1 11, filter plate 2 21, filter plate 3 31 and filter plate 4 41 are all ceramic microporous filter elements, and the filter diameters are 1 μm, 0.5 μm, 0.2 μm and 0.1 μm respectively, which are used to better filter out impurities and improve purity.

[0038] In a preferred embodiment, the upper parts of the dissolution zone 1, impurity removal zone 1 2, impurity removal zone 2 3 and sedimentation water washing zone 4 are all provided with an exhaust pipe L4 for balancing the pressure and collecting tail gas; the dissolution zone 1 and the sedimentation water washing zone 4 are provided with an agitator M1, which is respectively used for full dissolution and precipitation; the bottom of the waste liquid zone 5 is provided with a wastewater pipe L5 for discharging filtered wastewater and washing wastewater to the outside.

[0039] In the above embodiment, the liquid flow of the dissolution zone 1, impurity removal zone 1 2, impurity removal zone 2 3, sedimentation water washing zone 4 and waste liquid zone 5 arranged on the same plane can be achieved by fixing the tank body 100 as a whole on the operating platform, and by raising the left side (one end of the dissolution zone) so that the liquid of the upper stage flows into the next stage by gravity, thereby realizing the complete transfer of the liquid in the operating area after completing a unit operation.

[0040] In a second embodiment, a method for preparing high-purity antimony trioxide according to the first embodiment is proposed, the steps are:

[0041] 1) Add hydrochloric acid to 1 kg of 3N antimony oxide to dissolve, and filter to obtain filtrate 1;

[0042] 2) Slowly introducing micro-nano bubbles 1 into filtrate 1 from bottom to top, and filtering to obtain filtrate 2;

[0043] 3) slowly introducing micro-nano bubbles 2 into filtrate 2 from bottom to top, and filtering to obtain filtrate 3;

[0044] 4) adding ammonia water to the filtrate 3 to precipitate antimony, filtering to obtain wet antimony trioxide, washing the precipitate with ammonia water and deionized water in turn, and drying to obtain high-purity antimony trioxide;

[0045] The introduction time of the micro-nano bubble 1 and the micro-nano bubble 2 is 3-60 minutes, and they contain inert gas and 0.5-10L of hydrogen sulfide respectively.

[0046] In a preferred embodiment, the size of the micro-nano bubble 1 and / or the micro-nano bubble 2 is 100 nm to 100 μm, and the flow rate of the micro-nano bubble 1 and / or the micro-nano bubble 2 is 0.1-5 L / min.

[0047] In a preferred embodiment, the volume proportion of the inert gas in the micro-nano bubble 1 is 10-50%; and / or the volume proportion of the inert gas in the micro-nano bubble 2 is 10-30%.

[0048] In a preferred embodiment, in step a), the hydrochloric acid concentration is 3-12 mol / L and the volume is 3-9 L, so that antimony dioxide is fully dissolved. In step d), the ammonia water concentration used in the antimony precipitation process is 25-28%, and the amount used is 6 times the volume of the hydrochloric acid in step a), so that it is fully precipitated.

[0049] In a preferred embodiment, in step d), the drying temperature is 70-200° C. and the drying time is 2-20 h.

[0050] The following are preferred implementation examples of the present invention. Unless otherwise specified, the raw materials and reagents involved are all commercially available standard products, and the experiments or testing methods are all known methods commonly used by people in the field.

[0051] Example 1

[0052] A method for preparing high-purity antimony trioxide, comprising the steps of:

[0053] 1) Add 7 L of 3 mol / L hydrochloric acid to 1 kg of 3N antimony oxide to dissolve it, and filter it at a diameter of 1 μm to obtain filtrate 1;

[0054] 2) Adding mixed micro-nano bubbles of hydrogen sulfide and nitrogen from bottom to top into the filtrate 1 for 5 minutes, with a bubble flow rate of 3 L / min and a volume proportion of hydrogen sulfide of 50%; filtering at a diameter of 0.5 μm to obtain filtrate 2;

[0055] 3) Adding mixed micro-nano bubbles of hydrogen sulfide and nitrogen from bottom to top into the filtrate 2 for 8 minutes, with a gas flow rate of 2 L / min and a hydrogen sulfide gas volume of 30%; filtering at a diameter of 0.2 μm to obtain a filtrate 3;

[0056] 4) Continuously adding 28% ammonia water to the filtrate 3 to precipitate antimony. Stop adding ammonia water when no more precipitate is formed. Filter the precipitate, wash it with ammonia water and deionized water respectively, and then dry it at 150° C. for 8 h to obtain high-purity antimony trioxide.

[0057] Example 2

[0058] A method for preparing high-purity antimony trioxide, comprising the steps of:

[0059] 1) Add 4 L of 5 mol / L hydrochloric acid to 1 kg of 3N antimony oxide to dissolve it, and filter it at a diameter of 1 μm to obtain filtrate 1;

[0060] 2) Adding mixed micro-nano bubbles of hydrogen sulfide and nitrogen from bottom to top into the filtrate 1 for 12 minutes, with a bubble flow rate of 2 L / min and a volume proportion of hydrogen sulfide of 20%; filtering at a diameter of 0.5 μm to obtain filtrate 2;

[0061] 3) Adding mixed micro-nano bubbles of hydrogen sulfide and nitrogen from bottom to top into the filtrate 2 for 15 minutes, with a gas flow rate of 1 L / min and a hydrogen sulfide gas volume of 25%; filtering at a diameter of 0.2 μm to obtain filtrate 3;

[0062] 4) Continuously adding 28% ammonia water to the filtrate 3 to precipitate antimony. Stop adding ammonia water when no more precipitate is formed. Filter the precipitate, wash it with ammonia water and deionized water respectively, and then dry it at 200° C. for 4 h to obtain high-purity antimony trioxide.

[0063] Example 3

[0064] A method for preparing high-purity antimony trioxide, comprising the steps of:

[0065] 1) Add 5 L of 4 mol / L hydrochloric acid to 1 kg of 3N antimony oxide to dissolve it, and filter it at a diameter of 1 μm to obtain filtrate 1;

[0066] 2) Adding mixed micro-nano bubbles of hydrogen sulfide and nitrogen from bottom to top into the filtrate 1 for 30 minutes, with a bubble flow rate of 0.5 L / min and a volume proportion of hydrogen sulfide of 20%; filtering at a diameter of 0.5 μm to obtain filtrate 2;

[0067] 3) Introduce a mixture of hydrogen sulfide and nitrogen micro-nano bubbles from bottom to top into the filtrate 2 for 40 minutes, with a gas flow rate of 0.8 L / min and a hydrogen sulfide gas volume of 10%; filter at a diameter of 0.2 μm to obtain a filtrate 3;

[0068] 4) Continuously adding 28% ammonia water to the filtrate 3 to precipitate antimony. Stop adding ammonia water when no more precipitate is formed. Filter the precipitate, wash it with ammonia water and deionized water respectively, and then dry it at 100° C. for 12 h to obtain high-purity antimony trioxide.

[0069] Comparative Example 1

[0070] The method for preparing antimony trioxide has the same steps as those in Example 3, except that in step 2) and step 3), a mixed gas of hydrogen sulfide and nitrogen is introduced instead of micro-nano bubbles.

[0071] Comparative Example 2

[0072] The method for preparing antimony trioxide has the same steps as in Example 3, except that step 3) is omitted and filtrate 2 is directly used to precipitate antimony.

[0073] Comparative Example 3

[0074] The method for preparing antimony trioxide has the same steps as in Example 3, except that the time for adding the mixed micro-nano bubbles in step 2) is 1 hour.

[0075] The ICP test results of the final antimony trioxide products of the above Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0076] Table 1:

[0077]

[0078] It is not difficult to see from Table 1 that the purity of antimony trioxide obtained by the preparation method described in Examples 1-3 is more than 5N, which can meet the purity requirements of high-purity or even electronic-grade antimony trioxide. When the impurity removal process in Comparative Example 1 is not respectively using micro-nano mixed bubbles, the impurity content is high. The possible reason is that the micro-nano bubbles can promote the violent flow of the solution system during the rising process, and then promote the combination with impurities such as arsenic, copper, bismuth, and cadmium with the gasification of hydrogen sulfide to generate insolubles, thereby improving the impurity removal efficiency. Reducing the impurity removal process once in Comparative Example 2 leads to a decrease in purity, indicating the necessity of using secondary stock bubble impurity removal. The possible reason is that the above-mentioned precipitation may be dissociated at low temperatures, resulting in incomplete precipitation of impurities. However, the bubbling time extension in Comparative Example 3 is not conducive to the precipitation of impurities. The possible reason is that the violent impact and excessive hydrogen sulfide cause the pH value to decrease, causing the sulfide precipitate to partially dissolve.

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

Claims

1. A method for preparing high-purity antimony trioxide, characterized in that the steps include: a) adding hydrochloric acid to 1 kg of 3N antimony oxide to dissolve it, and filtering to obtain filtrate 1; b) slowly introducing micro-nano bubbles 1 into filtrate 1 from bottom to top, and filtering to obtain filtrate 2; c) slowly introducing micro-nano bubbles 2 into the filtrate 2 from bottom to top, and filtering to obtain a filtrate 3; d) adding ammonia water to the filtrate 3 to precipitate antimony, filtering to obtain wet antimony trioxide, washing the precipitate with ammonia water and deionized water in sequence, and drying to obtain high-purity antimony trioxide; The introduction time of the micro-nano bubble 1 and the micro-nano bubble 2 is 3-60 minutes, and contains inert gas and 0.5-10L of hydrogen sulfide.

2. The method according to claim 1, characterized in that The size of the micro-nano bubble 1 and / or micro-nano bubble 2 is 100 nm to 100 μm.

3. The method according to claim 1, characterized in that The flow rate of the micro-nano bubble 1 and / or micro-nano bubble 2 is 0.1-5 L / min.

4. The method according to claim 1, characterized in that The volume proportion of the inert gas in the first micro-nano bubble is 10-50%; and / or the volume proportion of the inert gas in the second micro-nano bubble is 10-30%.

5. The method according to claim 1, characterized in that In step a), the hydrochloric acid concentration is 3-12 mol / L, and the usage volume is 3-9 L.

6. The method according to claim 1, characterized in that In step d), the concentration of ammonia water used in the antimony precipitation process is 25-28%, and the amount used is 6 times the volume of hydrochloric acid in step a).

7. The method according to claim 1, characterized in that In step d), the drying temperature is 70-200° C. and the drying time is 2-20 h.

8. The method according to claim 1, characterized in that In steps a) to d), the filtering process uses filter media with filter diameters of 1 μm, 0.5 μm, 0.2 μm and 0.1 μm respectively.

9. The device used in the method for preparing high-purity antimony trioxide according to claim 1 is characterized in that: The tank body (100) is divided by four partitions (200) to form a dissolution zone (1), a first impurity removal zone (2), a second impurity removal zone (3), a precipitation water washing zone (4) and a waste liquid zone (5) which are arranged adjacent to each other on the left and right; each of the partitions (100) is movably arranged, and a filter plate is arranged on the right side of each partition (100); The bottoms of the impurity removal zone 1 (2) and the impurity removal zone 2 (3) are respectively provided with an air inlet pipe 1 (L2) and an air inlet pipe 2 (L3), both of which are connected to the micro-nano bubble generator.

10. The device according to claim 9, characterized in that An exhaust pipe (L4) is provided at the top of at least one of the dissolution zone (1), impurity removal zone 1 (2), impurity removal zone 2 (3), and precipitation water washing zone (4); and / or, a stirrer (M1) is provided in the dissolution zone (1) and the precipitation water washing zone (4); And / or, a waste water pipe (L5) is provided at the bottom of the waste liquid area (5).

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