A method for preparing zinc sulfide by water bath method

Abstract

The present application discloses a method for preparing zinc sulfide by a water bath method, comprising the following steps: S1, mixing a zinc source aqueous solution and a sulfur source aqueous solution to obtain a mixed solution; S2, subjecting the mixed solution to a water bath reaction to obtain a zinc sulfide precursor solution; S3, heating the zinc sulfide precursor solution to obtain a zinc sulfide solution; S4, filtering and washing the zinc sulfide solution, beating it with a chloride solution, then filtering, washing, and drying it; S5, calcining the dried product from step S4 in a protective atmosphere, placing the calcined product in dilute sulfuric acid and stirring it, then filtering, washing, and drying it to obtain zinc sulfide. The present application mixes a zinc source aqueous solution and a sulfur source aqueous solution, subjecting them to a water bath reaction to directly generate a zinc sulfide precursor solution, and then subjecting the zinc sulfide precursor solution to a heating reaction to obtain an aqueous solution containing zinc sulfide crystals. The preparation process is simple, the raw materials are cheap and readily available, and the production cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of zinc sulfide pigment preparation, and in particular to a method for preparing zinc sulfide by a water bath method. Background Art

[0002] Zinc sulfide is easily dispersed, resists agglomeration, and has a neutral white color. As a white pigment, it is widely used in plastics, coatings, and inks. There are various methods for synthesizing zinc sulfide, and numerous domestic reports on zinc sulfide, particularly nano-zinc sulfide, have been published. For example, patents with publication numbers CN 1821082A and CN 108383150A both disclose processes for preparing zinc sulfide.

[0003] Patent publication number CN 1821082A discloses that "an aqueous solution of zinc sulfate and sodium thiosulfate is first prepared and mixed to form a reaction mixture. A surfactant, polyethylene glycol or sodium lauryl sulfate, is then added to the mixture, followed by isopropyl alcohol as a free radical / OH scavenger. The mixture is irradiated with an electron beam generated by an electron accelerator, and after irradiation, the mixture is separated, washed, and dried to produce nano zinc sulfide powder." The use of an irradiation reaction increases production costs, and the addition of other additives, such as surfactants and free radical / OH scavengers, during the zinc sulfide production process is not environmentally friendly.

[0004] Patent publication number CN 108383150A discloses "mixing an aqueous solution of a zinc salt and an aqueous solution of a thiocyanate to prepare a zinc ion-thiocyanate precursor system, reacting the mixture with an aqueous solution of a sulfide at room temperature for 1 to 24 hours, filtering and washing, and then baking and drying the product to obtain a zinc sulfide nanomaterial." This patent does not directly generate the zinc sulfide precursor system, but requires first preparing the zinc ion-thiocyanate precursor system, which increases the preparation cost.

[0005] Therefore, there is an urgent need for a preparation process for zinc sulfide that is simple, low-cost, and environmentally friendly, and the zinc sulfide produced can better meet the use requirements of pigment grade. Summary of the Invention

[0006] In order to solve at least one of the above technical problems, a preparation process for zinc sulfide with simple process, low cost, environmental protection and pollution-free is developed, and the prepared zinc sulfide can better meet the use requirements of pigment grade. The present application provides a method for preparing zinc sulfide by water bath method.

[0007] The present application provides a method for preparing zinc sulfide by a water bath method, comprising the following steps:

[0008] S1, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1: (0.5-3) to prepare a mixed solution;

[0009] S2, reacting the mixed solution in a water bath, maintaining the pH at 3 to 7 during the reaction, to obtain a zinc sulfide precursor solution;

[0010] S3, heating the zinc sulfide precursor solution to obtain a zinc sulfide solution;

[0011] S4, filtering and washing the zinc sulfide solution, beating the solution with a chloride solution, and then filtering, washing, and drying the solution;

[0012] S5. In a protective atmosphere, calcining the product obtained after drying in step S4, placing the calcined product in dilute sulfuric acid and stirring it, and then filtering, washing, and drying it to obtain the zinc sulfide.

[0013] By adopting the above technical solution, the present application mixes a zinc source aqueous solution and a sulfur source aqueous solution, performs a water bath reaction, and directly generates a zinc sulfide precursor solution. The zinc sulfide precursor solution is then heated to react to produce an aqueous solution containing zinc sulfide crystals. Thereafter, the aqueous solution is washed and dried to produce pigment-grade zinc sulfide. The production process is environmentally friendly, the preparation process is simple, and the raw materials are cheap and readily available, thereby reducing production costs. The present application first performs a water bath treatment, so that the zinc source and the sulfur source react more fully, reducing the generation of impurities, thereby improving the purity of the zinc sulfide, so that the prepared zinc sulfide can better meet the use requirements of pigment grade.

[0014] Optionally, in step S1, the zinc source aqueous solution is prepared by dissolving zinc sulfate heptahydrate in secondary water to obtain the zinc source aqueous solution with a mass concentration of 50 to 300 g / L.

[0015] By adopting the above technical solution, zinc sulfate heptahydrate is cheap and easy to obtain, and can be fully dissolved in water.

[0016] Optionally, in step S1, the sulfur source aqueous solution is prepared by dissolving sodium sulfide nonahydrate in secondary water to obtain the sulfur source aqueous solution with a mass concentration of 50 to 300 g / L.

[0017] By adopting the above technical solution, sodium sulfide nonahydrate is cheap and easy to obtain, and can be fully dissolved in water.

[0018] Optionally, in step S2, the temperature of the water bath is 50-100° C., and the water bath time is 30-90 min.

[0019] By adopting the above technical solution, the mixed solution of the zinc source aqueous solution and the sulfur source aqueous solution is subjected to a water bath treatment, so that the zinc source and the sulfur source can react more fully, reducing the generation of impurities, thereby improving the purity of the zinc sulfide, so that the prepared zinc sulfide can better meet the use requirements of pigment grade.

[0020] Optionally, in step S3, the zinc sulfide precursor solution is heated in a reactor.

[0021] By adopting the above technical solution, the high temperature and high pressure conditions in the reactor can better promote the growth of zinc sulfide grains.

[0022] Optionally, in step S3, the temperature of the heating treatment is 110 to 180° C., and the time of the heating treatment is 0.5 to 7 hours.

[0023] Optionally, in step S4, the chloride salt solution is a sodium chloride solution, the mass concentration of the chloride salt is 50 to 300 g / L, and the beating time is 0.5 to 3 h.

[0024] Optionally, in step S4, the drying is vacuum drying, the drying temperature is 40-120° C., and the drying time is 1-3 hours.

[0025] Optionally, in step S5, the calcination temperature is 600-750° C., and the calcination time is 0.5-3 h.

[0026] By adopting the above technical solution, the crystal form of zinc sulfide is fully transformed.

[0027] Optionally, in step S5, the pH of the dilute sulfuric acid is 2 to 6, the stirring temperature is 70 to 100° C., and the stirring time is 0.5 to 3 hours.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects:

[0029] 1. The present application mixes a zinc source aqueous solution and a sulfur source aqueous solution, performs a water bath reaction, and directly generates a zinc sulfide precursor solution. The zinc sulfide precursor solution is then heated to react to obtain an aqueous solution containing zinc sulfide crystals. Thereafter, the aqueous solution is filtered, washed, and dried to obtain pigment-grade zinc sulfide. The production process is environmentally friendly, the preparation process is simple, and the raw materials are cheap and readily available, thereby reducing production costs.

[0030] 2. The present application first performs water bath treatment to allow the zinc source and the sulfur source to react more fully, reducing the generation of impurities, thereby improving the purity of the zinc sulfide and making the prepared zinc sulfide better meet the use requirements of pigment grade.

[0031] 3. The zinc sulfate heptahydrate and sodium sulfide nonahydrate of the present application are cheap and readily available, and no other additives are required in the crystallization process, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the X-ray diffraction (XRD) pattern of zinc sulfide prepared in Example 1;

[0033] Figure 2Schematic diagram of the particle size distribution of zinc sulfide prepared in Example 1;

[0034] Figure 3 Schematic diagram of the scanning electron microscope (SEM) of the zinc sulfide prepared in Example 1. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] The present application designs a method for preparing zinc sulfide using a water bath method.

[0037] The present invention provides a method for preparing zinc sulfide by a water bath method, comprising the following steps:

[0038] S1, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1: (0.5-3) to prepare a mixed solution;

[0039] S2, reacting the mixed solution in a water bath, maintaining the pH at 3 to 7 during the reaction, to obtain a zinc sulfide precursor solution;

[0040] S3, heating the zinc sulfide precursor solution to obtain a zinc sulfide solution;

[0041] S4, filtering and washing the zinc sulfide solution, beating the solution with a chloride solution, and then filtering, washing, and drying the solution;

[0042] S5. In a protective atmosphere, calcining the product obtained after drying in step S4, placing the calcined product in dilute sulfuric acid and stirring it, and then filtering, washing, and drying it to obtain the zinc sulfide.

[0043] The present invention involves mixing a zinc source aqueous solution and a sulfur source aqueous solution, performing a water bath reaction, and directly generating a zinc sulfide precursor solution. The zinc sulfide precursor solution is then heated to react to produce an aqueous solution containing zinc sulfide crystals. The aqueous solution is then washed and dried to produce pigment-grade zinc sulfide. The production process is environmentally friendly, the preparation process is simple, and the raw materials are inexpensive and readily available, thereby reducing production costs. The present invention first performs a water bath treatment to allow the zinc source and the sulfur source to react more fully, reducing the generation of impurities, thereby improving the purity of the zinc sulfide and ensuring that the prepared zinc sulfide better meets the requirements for pigment-grade use. Specific embodiments

[0045] Zinc sulfate heptahydrate is industrial grade with a purity of more than 99.5%; sodium sulfide nonahydrate is industrial grade with a purity of more than 99.5%; sodium chloride is analytical grade with a purity of more than 99.5%; secondary water refers to water that has been distilled twice.

[0046] Example 1

[0047] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0048] S1, dissolving zinc sulfate heptahydrate in secondary water to obtain a zinc source aqueous solution with a mass concentration of 100g / L, which is set aside; dissolving sodium sulfide nonahydrate in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 100g / L, which is set aside;

[0049] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:1 to prepare a mixed solution;

[0050] S3, reacting the mixed solution in a water bath, maintaining the pH at 4 during the reaction, the water bath temperature at 60° C., and the water bath time at 50 min to obtain a zinc sulfide precursor solution;

[0051] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 130° C. for 3 h to obtain a zinc sulfide solution;

[0052] S5, the zinc sulfide solution is filtered and washed, and then beaten with a sodium chloride aqueous solution for 1 hour, the mass concentration of sodium chloride is 100g / L, after which it is filtered, washed, and dried, and the drying is vacuum drying at a drying temperature of 80°C and a drying time of 1 hour;

[0053] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 600° C. for 3 h. The calcined product is stirred in dilute sulfuric acid with a pH of 3 at a temperature of 70° C. for 1 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0054] The X-ray diffraction (XRD) pattern of zinc sulfide is as follows Figure 1 As shown; the particle size distribution of zinc sulfide is as follows Figure 2 As shown; the scanning electron microscope (SEM) image of zinc sulfide is as follows Figure 3 shown.

[0055] Example 2

[0056] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0057] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 50g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 70g / L, and the solution was set aside;

[0058] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:0.5 to prepare a mixed solution;

[0059] S3, reacting the mixed solution in a water bath, maintaining the pH at 3, the water bath temperature at 60° C., and the water bath time at 90 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0060] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 110° C. for 7 hours to obtain a zinc sulfide solution;

[0061] S5, the zinc sulfide solution was filtered and washed, and then beaten with a sodium chloride aqueous solution for 0.5h, the mass concentration of sodium chloride was 50g / L, and then filtered, washed, and dried. The drying was vacuum drying at a drying temperature of 40°C and a drying time of 3h;

[0062] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 700° C. for 2 h. The calcined product is placed in dilute sulfuric acid with a pH of 4.5 and stirred at a temperature of 90° C. for 0.5 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0063] Example 3

[0064] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0065] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 80g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 50g / L, and the solution was set aside;

[0066] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:2 to prepare a mixed solution;

[0067] S3, reacting the mixed solution in a water bath, maintaining the pH at 7, the water bath temperature at 60° C., and the water bath time at 70 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0068] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 120° C. for 6 h to obtain a zinc sulfide solution;

[0069] S5, the zinc sulfide solution was filtered and washed, and then beaten with a sodium chloride aqueous solution for 1 hour, the mass concentration of sodium chloride was 70g / L, and then filtered, washed, and dried. The drying was vacuum drying at a drying temperature of 80°C and a drying time of 1 hour;

[0070] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 was calcined at a temperature of 650° C. for 1.5 h. The calcined product was placed in dilute sulfuric acid with a pH of 6 and stirred at 90° C. for 1.5 h. After stirring, the product was filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0071] Example 4

[0072] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0073] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 160g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 130g / L, and the solution was set aside;

[0074] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:3 to prepare a mixed solution;

[0075] S3, reacting the mixed solution in a water bath, maintaining the pH at 6 during the reaction, the water bath temperature at 100° C., and the water bath time at 30 min to obtain a zinc sulfide precursor solution;

[0076] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 150° C. for 4.5 hours to obtain a zinc sulfide solution;

[0077] S5. After filtering and washing the zinc sulfide solution, slurrying with a sodium chloride aqueous solution for 3 hours, the mass concentration of sodium chloride is 300 g / L, and then filtering, washing, and drying. The drying is vacuum drying, the drying temperature is 120°C, and the drying time is 1.5 hours; S6. In a nitrogen atmosphere, the product dried in step S5 is calcined at a calcination temperature of 700°C and a calcination time of 2 hours. The calcined product is placed in dilute sulfuric acid with a pH of 5.5 and stirred at a stirring temperature of 75°C and a stirring time of 2.5 hours. After stirring, filtering, washing, and drying are the same as those in step S5 to obtain zinc sulfide.

[0078] Example 5

[0079] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0080] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 190g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 210g / L, and the solution was set aside;

[0081] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:0.6 to prepare a mixed solution;

[0082] S3, reacting the mixed solution in a water bath, maintaining the pH at 6.5, the water bath temperature at 50° C., and the water bath time at 60 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0083] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 180° C. for 0.5 h to obtain a zinc sulfide solution;

[0084] S5, the zinc sulfide solution was filtered and washed, and then beaten with sodium chloride aqueous solution for 2.5h, the mass concentration of sodium chloride was 85g / L, after which it was filtered, washed, and dried. The drying was vacuum drying at a drying temperature of 110°C and a drying time of 1.5h;

[0085] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 750° C. for 0.5 h. The calcined product is placed in dilute sulfuric acid with a pH of 4 and stirred at a temperature of 80° C. for 3 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0086] Example 6

[0087] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0088] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 300g / L, which was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 300g / L, which was set aside;

[0089] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:1.2 to prepare a mixed solution;

[0090] S3, reacting the mixed solution in a water bath, maintaining the pH at 4.5, the water bath temperature at 90° C., and the water bath time at 35 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0091] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 160° C. for 2 h to obtain a zinc sulfide solution;

[0092] S5, the zinc sulfide solution was filtered and washed, and then beaten with a sodium chloride aqueous solution for 1 hour, the mass concentration of sodium chloride was 150g / L, after which it was filtered, washed, and dried, and the drying was vacuum drying at a drying temperature of 120°C and a drying time of 1 hour;

[0093] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 650° C. for 1 h. The calcined product is placed in dilute sulfuric acid with a pH of 2 and stirred at a temperature of 80° C. for 1.5 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0094] Example 7

[0095] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0096] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 270g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 280g / L, and the solution was set aside;

[0097] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:0.7 to prepare a mixed solution;

[0098] S3, reacting the mixed solution in a water bath, maintaining the pH at 5, the water bath temperature at 70° C., and the water bath time at 45 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0099] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 110° C. for 6.5 h to obtain a zinc sulfide solution;

[0100] S5, the zinc sulfide solution was filtered and washed, and then beaten with sodium chloride aqueous solution for 1.5 hours, the mass concentration of sodium chloride was 210g / L, after which it was filtered, washed, and dried, and the drying was vacuum drying at a drying temperature of 90°C and a drying time of 3 hours;

[0101] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 700° C. for 3 h. The calcined product is placed in dilute sulfuric acid with a pH of 5 and stirred at 95° C. for 2 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0102] Example 8

[0103] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0104] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 210g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 190g / L, and the solution was set aside;

[0105] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:2.5 to prepare a mixed solution;

[0106] S3, reacting the mixed solution in a water bath, maintaining the pH at 5.5, the water bath temperature at 50° C., and the water bath time at 75 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0107] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 170° C. for 1.5 h to obtain a zinc sulfide solution;

[0108] S5, the zinc sulfide solution was filtered and washed, and then beaten with sodium chloride aqueous solution for 2h, the mass concentration of sodium chloride was 120g / L, after which it was filtered, washed, and dried, and the drying was vacuum drying at a drying temperature of 100°C and a drying time of 2h;

[0109] S6. In a nitrogen atmosphere, the product obtained after drying in step S5 is calcined at a temperature of 750° C. for 1 h. The calcined product is placed in dilute sulfuric acid with a pH of 2.5 and stirred at a temperature of 85° C. for 1 h. After stirring, the product is filtered, washed, and dried under the same conditions as those in step S5 to obtain zinc sulfide.

[0110] Example 9

[0111] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0112] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 230g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 230g / L, and the solution was set aside;

[0113] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:2.3 to prepare a mixed solution;

[0114] S3, reacting the mixed solution in a water bath, maintaining the pH at 4 during the reaction, the water bath temperature at 80° C., and the water bath time at 55 min to obtain a zinc sulfide precursor solution;

[0115] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 140° C. for 5 hours to obtain a zinc sulfide solution;

[0116] S5. After filtering and washing the zinc sulfide solution, slurrying with a sodium chloride aqueous solution for 2 hours, the mass concentration of sodium chloride is 260 g / L, and then filtering, washing, and drying. The drying is vacuum drying at a drying temperature of 110° C. and a drying time of 2.5 hours. S6. In a nitrogen atmosphere, calcining the product after drying in step S5 at a calcination temperature of 750° C. and a calcination time of 1 hour. The calcined product is placed in dilute sulfuric acid with a pH of 5 and stirred at a stirring temperature of 95° C. and a stirring time of 2 hours. After stirring, filtering, washing, and drying are carried out. The drying conditions are the same as those in step S5 to obtain zinc sulfide.

[0117] Example 10

[0118] A method for preparing zinc sulfide by a water bath method comprises the following steps:

[0119] S1, zinc sulfate heptahydrate was dissolved in secondary water to obtain a zinc source aqueous solution with a mass concentration of 130g / L, and the solution was set aside; sodium sulfide nonahydrate was dissolved in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 150g / L, and the solution was set aside;

[0120] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:1.5 to prepare a mixed solution;

[0121] S3, reacting the mixed solution in a water bath, maintaining the pH at 5, the water bath temperature at 85° C., and the water bath time at 65 min during the reaction process, to obtain a zinc sulfide precursor solution;

[0122] S4, placing the zinc sulfide precursor solution into a reactor and heating it at a temperature of 170° C. for 1 h to obtain a zinc sulfide solution;

[0123] S5, the zinc sulfide solution was filtered and washed, and then beaten with sodium chloride aqueous solution for 1 hour, the mass concentration of sodium chloride was 175g / L, after which it was filtered, washed, and dried, and the drying was vacuum drying at a drying temperature of 60°C and a drying time of 3 hours;

[0124] S6. In a nitrogen atmosphere, the product dried in step S5 was calcined at a temperature of 700° C. for 2.5 h. The calcined product was placed in dilute sulfuric acid with a pH of 3.5 and stirred at a temperature of 100° C. for 1 h. After stirring, the product was filtered, washed, and dried under the same drying conditions as in step S5 to obtain zinc sulfide.

[0125] Comparative Example 1

[0126] The preparation method of zinc sulfide comprises the following steps:

[0127] S1, dissolving zinc sulfate heptahydrate in secondary water to obtain a zinc source aqueous solution with a mass concentration of 100g / L, which is set aside; dissolving sodium sulfide nonahydrate in secondary water to obtain a sulfur source aqueous solution with a mass concentration of 100g / L, which is set aside;

[0128] S2, mixing the zinc source aqueous solution and the sulfur source aqueous solution in a mass ratio of 1:1 to prepare a mixed solution;

[0129] S3, placing the mixed solution into a reactor and heating it at a temperature of 130° C. for 3 h;

[0130] S4, the product after heating in step S3 is filtered and washed, and then beaten with a sodium chloride aqueous solution for 1 hour, the mass concentration of sodium chloride is 100g / L, and then filtered, washed, and dried. The drying is vacuum drying at a drying temperature of 80°C and a drying time of 1 hour;

[0131] S5. In a nitrogen atmosphere, the product dried in step S5 is calcined at a temperature of 600° C. for 3 h. The calcined product is placed in dilute sulfuric acid with a pH of 3 and stirred at 70° C. for 1 h. After stirring, the product is filtered, washed, and dried under the same drying conditions as in step S4 to obtain zinc sulfide.

[0132] The difference between Comparative Example 1 and Example 1 is that there is no water bath heating step in Comparative Example 1.

[0133] Performance Testing

[0134] The zinc sulfide products prepared in Examples 1 to 10 and Comparative Example 1 were tested for ZnS content and particle size (D50) of the zinc sulfide products according to the test method in GB / T 31194-2014. The test results are shown in Table 1 below.

[0135] Table 1

[0136]

[0137] From the test results in Table 1, it can be seen that the purity of the zinc sulfide products obtained in Examples 1 to 10 is not less than 99%. However, in Comparative Example 1, since there is no water bath step and the mixed solution of the zinc source aqueous solution and the sulfur source aqueous solution is directly heated, impurities are generated during the reaction, resulting in the purity of the obtained zinc sulfide product not exceeding 97.5%.

[0138] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing zinc sulfide by a water bath method, characterized in that: The steps include: S1. Mixing a zinc source aqueous solution and a sulfur source aqueous solution in a mass ratio of 1:(0.5-3) to prepare a mixed solution; S2, reacting the mixed solution in a water bath at a temperature of 50 to 100° C. for 30 to 90 minutes, maintaining the pH at 3 to 7 during the reaction, to obtain a zinc sulfide precursor solution; S3, adding the zinc sulfide precursor solution into a reactor, and heating it under high temperature and high pressure conditions to obtain a zinc sulfide solution, wherein the heating temperature is 110 to 180° C. and the heating time is 0.5 to 7 hours; S4, filtering and washing the zinc sulfide solution, beating with a chloride solution, then filtering, washing, and drying, wherein the chloride solution is a sodium chloride solution, the mass concentration of the chloride is 50 to 300 g / L, and the beating time is 0.5 to 3 h; S5. In a protective atmosphere, calcining the dried product of step S4, placing the calcined product in dilute sulfuric acid and stirring it, then filtering, washing, and drying it to obtain the zinc sulfide, the calcination temperature is 600-750° C., and the calcination time is 0.5-3 h.

2. The method for preparing zinc sulfide by water bath method according to claim 1, wherein In step S1, the zinc source aqueous solution is prepared by dissolving zinc sulfate heptahydrate in secondary water to obtain the zinc source aqueous solution with a mass concentration of 50 to 300 g / L.

3. The method for preparing zinc sulfide by water bath method according to claim 1, characterized in that, In step S1, the sulfur source aqueous solution is prepared by dissolving sodium sulfide nonahydrate in secondary water to obtain the sulfur source aqueous solution with a mass concentration of 50 to 300 g / L.

4. The method for preparing zinc sulfide by water bath method according to claim 1, wherein In step S4, the drying is vacuum drying, the drying temperature is 40-120° C., and the drying time is 1-3 hours.

5. The method for preparing zinc sulfide by water bath method according to claim 1, characterized in that, In step S5, the pH of the dilute sulfuric acid is 2-6, the stirring temperature is 70-100° C., and the stirring time is 0.5-3 h.

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