A method for preparing anhydrous nickel fluoride

Abstract

The present invention belongs to the technical field of hydrometallurgical generation of anhydrous nickel fluoride, and specifically relates to a method for preparing anhydrous nickel fluoride, wherein the preparation method uses nickel salt and ammonium hydrogen fluoride as raw materials, and obtains anhydrous nickel fluoride through four steps of liquid phase synthesis, filtration and washing, drying and grinding, and high temperature de-crystallization water. Compared with the prior art, the method for preparing anhydrous nickel fluoride provided by the present invention has the advantages of high safety, low equipment requirements, low production energy consumption, simple operation, good product batch stability, high purity, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgical generation of anhydrous nickel fluoride, and specifically relates to a preparation method of anhydrous nickel fluoride. Background Art

[0002] At present, the synthesis process of anhydrous nickel fluoride commonly used in industry mainly includes pyrolysis and wet process. The pyrolysis mainly uses nickel chloride to react with hydrogen fluoride or fluorine gas at high temperature for preparation. The reaction uses hydrogen fluoride and fluorine gas, which are highly toxic gases, and the sealing performance of the equipment is very high. The wet process mainly uses nickel carbonate or nickel hydroxide to react with hydrofluoric acid to first prepare nickel fluoride tetrahydrate, and then further removes crystal water for preparation. The hydrofluoric acid used in the reaction is extremely corrosive and can strongly corrode metals, glass and silicon-containing objects. At the same time, the volatilized hydrogen fluoride gas is highly toxic, such as inhaling steam or contacting the skin, which will cause difficult-to-heal burns. Chinese invention patent CN104326512B discloses a method for preparing nickel fluoride, using nickel carbonate and ammonium fluoride as raw materials, soluble carbonate as auxiliary raw materials, and nickel fluoride is obtained by nickel carbonate slurry, synthesis preparation, purification and impurity removal and washing, filtering and drying steps, but the method has the need to add soluble carbonate as auxiliary raw materials, resulting in increased production costs and increased difficulty in impurity removal.

[0003] Therefore, it is necessary to develop a method for preparing anhydrous nickel fluoride with high product purity and simple operation. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for preparing anhydrous nickel fluoride. The method can obtain anhydrous nickel fluoride with high product purity, good batch stability and extremely low impurity metal content through a simple preparation process without adding additional auxiliary raw materials.

[0005] Specifically, this method provides a method for preparing anhydrous nickel fluoride, using nickel salt and ammonium hydrogen fluoride as raw materials, and obtaining anhydrous nickel fluoride through four steps of liquid phase synthesis, filtration and washing, drying and grinding, and high temperature de-crystallization water. The specific steps are as follows:

[0006] S1. Liquid phase synthesis: Heat the dispersed nickel salt suspension to 70-90°C, slowly add ammonium bifluoride solution while stirring, and react at 70-90°C for 2-3h.

[0007] S2, Filtration and washing: The synthesized solution is filtered under reduced pressure, and the filtrate is returned to the preparation of the next ammonium bifluoride solution. The filter cake is washed 2 to 3 times with deionized water.

[0008] S3. Drying and grinding: The filter cake is placed in a constant temperature oven for drying, and after being taken out, a crusher is used to produce fine powder to obtain nickel fluoride tetrahydrate.

[0009] S4. High temperature de-crystallization water: The nickel fluoride tetrahydrate is placed in a muffle furnace and baked to obtain anhydrous nickel fluoride product.

[0010] According to one technical solution of the preparation method technical solution of the present invention, at least the following beneficial effects are achieved:

[0011] The preparation process of the present invention does not use highly corrosive and toxic substances such as fluorine gas and hydrofluoric acid, and does not require the addition of additional auxiliary raw materials. Compared with the prior art, the present invention has the advantages of high safety, low equipment requirements, low production energy consumption, simple operation, good product batch stability, and high purity.

[0012] According to some embodiments of the present invention, the nickel salt is one or more of anhydrous nickel carbonate, nickel carbonate hexahydrate, basic nickel carbonate, and nickel hydroxide.

[0013] According to some embodiments of the present invention, the mass ratio of deionized water to nickel salt in the nickel salt suspension in step S1 is 3-5:1.

[0014] According to some embodiments of the present invention, the mass ratio of water to ammonium bifluoride in the ammonium bifluoride solution in step S1 is 4-6:1.

[0015] According to some embodiments of the present invention, in step S1, the ratio of the amount of fluorine atoms in the ammonium bifluoride solution to the amount of nickel atoms in the nickel salt is 3-4:1.

[0016] According to some embodiments of the present invention, the stirring condition during the liquid phase synthesis in step S1 is a rotation speed of 500-700 r / min.

[0017] According to some embodiments of the present invention, the drying temperature of the constant temperature oven in step S3 is 85-95° C., and the drying time is 16-20 hours.

[0018] According to some embodiments of the present invention, the baking temperature during baking in the muffle furnace is 280-320° C., and the baking time is 5-7 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent from the description of the embodiments in conjunction with the following drawings.

[0020] Obvious and easy to understand, where:

[0021] Figure 1 The figure is the XRD spectrum of anhydrous nickel fluoride prepared in the embodiment of the present invention. Implementation

[0022] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments.

[0023] Fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0024] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0025] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0026] The specific embodiments of the present invention are described in detail below. Example 1

[0027] a: Liquid phase synthesis: Use 384g of deionized water and 96g of anhydrous nickel carbonate to prepare a suspension, heat to 70°C, adjust the speed to 600r / min, slowly add ammonium bifluoride solution prepared by using 440g of deionized water and 88g of ammonium bifluoride, and keep the reaction at 70°C for 3h.

[0028] b: Filtration and washing: The synthesized solution is filtered under reduced pressure, and the filtrate is returned to the preparation of the next ammonium bifluoride solution. The filter cake is washed twice with deionized water.

[0029] c: Drying and grinding: The filter cake was placed in a constant temperature oven at 90°C and baked for 18 hours. After being taken out, it was crushed into fine powder using a crusher to obtain light green nickel fluoride tetrahydrate.

[0030] d: High temperature de-crystallization water: The light green nickel fluoride tetrahydrate was placed in a muffle furnace at 300°C and baked for 6 hours to obtain a yellow-green anhydrous nickel fluoride product.

[0031] The composition of the synthesized anhydrous nickel fluoride was analyzed, and the results are shown in Table 1.

[0032] Element Name Ni Co Cu Fe Zn Pb Ca Mg Na content(%) 59.1 0.0004 0.0005 0.0089 0.0005 0.0004 0.10 0.015 0.0078 Example 2

[0033] a: Liquid phase synthesis: Use 427.5g of deionized water, 29.5g of nickel carbonate hexahydrate and 113g of basic nickel carbonate to prepare a suspension, heat to 80°C, adjust the speed to 500r / min, slowly add ammonium bifluoride solution prepared by using 352g of deionized water and 88g of ammonium bifluoride, and keep the reaction at 80°C for 2.5h.

[0034] b: Filtration and washing: The synthesized solution is filtered under reduced pressure, and the filtrate is returned to the preparation of the next ammonium bifluoride solution. The filter cake is washed twice with deionized water.

[0035] c: Drying and grinding: The filter cake was placed in a constant temperature oven at 85°C and baked for 20 hours. After being taken out, it was crushed into fine powder using a crusher to obtain light green nickel fluoride tetrahydrate.

[0036] d: High temperature de-crystallization water: The light green nickel fluoride tetrahydrate is placed in a muffle furnace at 280°C and baked for 7 hours to obtain a yellow-green anhydrous nickel fluoride product.

[0037] The composition of the synthesized anhydrous nickel fluoride was analyzed and the results are shown in Table 2.

[0038] Element Name Ni Co Cu Fe Zn Pb Ca Mg Na content(%) 59.3 0.0005 0.0005 0.0095 0.0006 0.0005 0.11 0.014 0.0091 Example 3

[0039] a: Liquid phase synthesis: Use 680g of deionized water, 36g of anhydrous nickel carbonate, 75g of basic nickel carbonate, and 25g of nickel hydroxide to prepare a suspension, heat to 90°C, adjust the speed to 700r / min, slowly add ammonium bifluoride solution prepared with 528g of deionized water and 88g of ammonium bifluoride, and keep the reaction at 90°C for 2h.

[0040] b: Filtration and washing: The synthesized solution is filtered under reduced pressure, and the filtrate is returned to the preparation of the next ammonium bifluoride solution. The filter cake is washed three times with deionized water.

[0041] c: Drying and grinding: The filter cake was placed in a constant temperature oven at 95°C and baked for 16 hours. After being taken out, it was crushed into fine powder using a crusher to obtain light green nickel fluoride tetrahydrate.

[0042] d: High temperature de-crystallization water: The light green nickel fluoride tetrahydrate was placed in a muffle furnace at 320°C and baked for 5 hours to obtain a yellow-green anhydrous nickel fluoride product.

[0043] The composition of the synthesized anhydrous nickel fluoride was analyzed and the results are shown in Table 3.

[0044] Element Name Ni Co Cu Fe Zn Pb Ca Mg Na content(%) 59.4 0.0004 0.0006 0.0085 0.0005 0.0004 0.13 0.011 0.0082

[0045] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. It should be pointed out that for ordinary technicians in this field, any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing anhydrous nickel fluoride, characterized in that: Using nickel salt and ammonium bifluoride as raw materials, anhydrous nickel fluoride is obtained through four steps of liquid phase synthesis, filtration and washing, drying and grinding, and high-temperature de-crystallization water. The specific steps are as follows: S1, liquid phase synthesis: the dispersed nickel salt suspension is heated to 70-90°C, and the ammonium bifluoride solution is slowly added while stirring, and the reaction is carried out at 70-90°C for 2-3 hours; S2, filtration and washing: the synthesized solution is filtered under reduced pressure, and the filtrate is returned to the preparation of the next ammonium bifluoride solution, and the filter cake is washed with deionized water for 2-3 times; S3, drying and grinding: the filter cake is placed in a constant temperature oven for drying, and after being taken out, it is crushed into fine powder using a crusher to obtain nickel fluoride tetrahydrate; S4, high-temperature de-crystallization water: the light green nickel fluoride tetrahydrate is placed in a muffle furnace for baking to obtain anhydrous nickel fluoride product; The nickel salt is one or more of anhydrous nickel carbonate, nickel carbonate hexahydrate, and basic nickel carbonate; The mass ratio of deionized water to nickel salt in the nickel salt suspension in step S1 is 3-5:1; The mass ratio of water to ammonium bifluoride in the ammonium bifluoride solution in step S1 is 4-6:1; In step S1, the ratio of the amount of fluorine atoms in the ammonium hydrogen fluoride solution to the amount of nickel atoms in the nickel salt is 3-4:1; The stirring speed in step S1 is 500-700 r / min; The drying temperature of the constant temperature oven in step S3 is 85-95°C, and the drying time is 16-20h; The baking temperature of the muffle furnace in step S4 is 280-320° C., and the baking time is 5-7 hours.

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