Basic zinc chloride particulate matter and preparation method therefor

Abstract

A basic zinc chloride particulate matter and a preparation method therefor. The basic zinc chloride particulate matter mainly consists of basic zinc chloride particles. In the basic zinc chloride particulate matter, D.sub.10>100 μm, and D.sub.95>450 μm. The basic zinc chloride particles do not contain adhesives. The basic zinc chloride particles contained in the basic zinc chloride particulate matter are approximately spherical, and the basic zinc chloride particles with the particle diameter>500 μm in the basic zinc chloride particulate matter accounts for 1% or less of the total mass of the basic zinc chloride particulate matter.

Claims

1. A basic zinc chloride particulate matter, wherein the basic zinc chloride particulate matter includes basic zinc chloride particles; the basic zinc chloride particulate matter has a D.sub.10 of more than 100 μm and a D.sub.95 of more than 450 μm; the basic zinc chloride particles are free of adhesives; most of the basic zinc chloride particles contained in the basic zinc chloride particulate matter have a sphere-like appearance, and the basic zinc chloride particles having a particle size of more than 500 μm in the basic zinc chloride particulate matter account for 1% or less of a total mass of the basic zinc chloride particulate matter.

2. The basic zinc chloride particulate matter according to claim 1, wherein the basic zinc chloride particulate matter has a particle size distribution range of 1 μm to 1000 μm.

3. The basic zinc chloride particulate matter according to claim 2, wherein the particles having the sphere-like appearance in the basic zinc chloride particulate matter account for 95% or more of the total mass of the particulate matter.

4. A feed additive, wherein the feed additive comprises the basic zinc chloride particulate matter according to claim 3.

5. A feed additive, wherein the feed additive comprises the basic zinc chloride particulate matter according to claim 2.

6. The basic zinc chloride particulate matter according to claim 1, wherein the particles having the sphere-like appearance in the basic zinc chloride particulate matter account for 95% or more of the total mass of the particulate matter.

7. A feed additive, wherein the feed additive comprises the basic zinc chloride particulate matter according to claim 6.

8. A feed additive, wherein the feed additive comprises the basic zinc chloride particulate matter according to claim 1.

9. A preparation method for the basic zinc chloride particulate matter according to claim 1, wherein the preparation method comprises the following steps: step S1, preparing a zinc chloride solution having a zinc concentration of 60 g/L to 150 g/L; step S2, preparing an ammonia solution having a pH of 10 or more, adding ammonium chloride as an inducer into the ammonia solution to prepare a mixed solution, with the ammonium chloride serving as a main source of chloride ions in the mixed solution, so that the mixed solution has an ammonia-nitrogen concentration of 140 g/L to 170 g/L and a chloride ion concentration of 80 g/L to 160 g/L; step S3, complexing and ammonia-leaching of a zinc-containing raw material by using a mixed solution obtained in step S2 to prepare a zinc-ammonia complex solution, with a zinc concentration in the zinc-ammonia complex solution being 60 g/L to 150 g/L; and step S4, adding water or a mother solution of the basic zinc chloride into a reaction vessel, heating to 70° C. to 90° C., and adding the zinc chloride solution in step S1 and the zinc-ammonia complex solution in step S3 simultaneously in a parallel feeding manner, maintaining a reaction pH value at 6.0 to 7.0, with a stirring speed of 1200 r/min to 1500 r/min, and reacting for 2 to 4 hours to obtain a precipitate and a zinc-containing mother solution, and washing and drying the precipitate to obtain the basic zinc chloride particulate matter.

10. The preparation method for the basic zinc chloride particulate matter according to claim 9, wherein the preparation method further comprises a step of sieving the dried precipitate after completing step S4 to remove the particles having relatively large particle size.

11. The preparation method for the basic zinc chloride particulate matter according to claim 10, wherein the zinc-containing mother solution in step S4 is subjected to alkali stripping and spraying absorption to recycle ammonia water.

12. The preparation method for the basic zinc chloride particulate matter according to claim 11, wherein after removing the ammonia-nitrogen by the alkali stripping, the zinc-containing mother solution in step S4 is subjected to depth removal of heavy metals, concentration and crystallization to recycle sodium chloride.

13. The preparation method for the basic zinc chloride particulate matter according to claim 10, wherein the zinc chloride solution in step S1 is prepared by the following method: using a zinc-containing flue dust as a raw material, leaching with acid, and removing impurities to obtain the zinc chloride solution.

14. The preparation method for the basic zinc chloride particulate matter according to claim 10, wherein the zinc-containing raw material is a zinc-containing flue dust, and when using the zinc-containing flue dust as the raw material, the obtained zinc-ammonia complex solution is further subjected to a step of adding zinc powder for replacement and removal of impurities.

15. The preparation method for the basic zinc chloride particulate matter according to claim 9, wherein the zinc-containing mother solution in step S4 is subjected to alkali stripping and spraying absorption to recycle ammonia water.

16. The preparation method for the basic zinc chloride particulate matter according to claim 15, wherein after removing the ammonia-nitrogen by the alkali stripping, the zinc-containing mother solution in step S4 is subjected to depth removal of heavy metals, concentration and crystallization to recycle sodium chloride.

17. The preparation method for the basic zinc chloride particulate matter according to claim 9, wherein the zinc chloride solution in step S1 is prepared by the following method: using a zinc-containing flue dust as a raw material, leaching with acid, and removing impurities to obtain the zinc chloride solution.

18. The preparation method for the basic zinc chloride particulate matter according to claim 9, wherein the zinc-containing raw material is a zinc-containing flue dust, and when using the zinc-containing flue dust as the raw material, the obtained zinc-ammonia complex solution is further subjected to a step of adding zinc powder for replacement and removal of impurities.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a particle size distribution diagram of a basic zinc chloride particulate matter prepared in Embodiment 1.

(2) FIG. 2 is a SEM diagram of magnification of 300 times the basic zinc chloride particulate matter prepared in Embodiment 1.

(3) FIG. 3 is a SEM diagram of magnification of 100 times the basic zinc chloride particulate matter prepared in Embodiment 1.

(4) FIG. 4 is a SEM diagram of magnification of 50 times the basic zinc chloride particulate matter prepared in Embodiment 1.

(5) FIG. 5 is a SEM diagram of magnification of 30 times the basic zinc chloride particulate matter prepared in Embodiment 1.

(6) FIG. 6 is a particle size distribution diagram of a commercially available basic zinc chloride product.

(7) FIG. 7 is a SEM diagram of magnification of 300 times the commercially available basic zinc chloride product.

(8) FIG. 8 is a SEM diagram of magnification of 100 times the commercially available basic zinc chloride product.

(9) FIG. 9 is a SEM diagram of magnification of 50 times the commercially available basic zinc chloride product.

(10) FIG. 10 is a SEM diagram of magnification of 30 times the commercially available basic zinc chloride product.

DESCRIPTION OF THE EMBODIMENTS

(11) The present disclosure is further described below in combination with specific implementations, but the present disclosure is not limited by the embodiments in any ways. Unless otherwise, raw materials and reagents used in the embodiments of the present disclosure are conventional raw materials and reagents which are commercially available.

(12) Commercially available basic zinc chloride was purchased from the commercially available product which conforms to Chinese standard Feed Additive—Basic Zinc Chloride (GB/T 22546-2008).

(13) Test method of angle of repose was performed according to Surface active agents—Powders and granules—Measurement of the angle of repose (GB/T 11986-1898).

(14) Particle size distribution, D.sub.10 and D.sub.95 were determined by using GB/T19077-2016 Laser Diffraction Methods.

(15) Morphology of the basic zinc chloride was observed by a scanning electron microscope.

Embodiments

(16) A preparation method for the basic zinc chloride particulate matter, includes the following steps: Step S1, zinc oxide was dissolved in a hydrochloric acid solution to prepare a zinc chloride solution;

(17) Step S2, an ammonia solution having a pH of 10 or more was prepared, ammonium chloride was added as an inducer into the ammonia solution to prepare a mixed solution, the ammonium chloride served as a main source of chloride ions in the mixed solution so that the mixed solution had an ammonia-nitrogen concentration of 140 g/L to 170 g/L and a chloride ion concentration of 80 g/L to 160 g/L;

(18) Step S3, zinc oxide was subjected to complexing and ammonia-leaching by using a mixed solution obtained in step S2 to prepare a zinc-ammonia complex solution; and

(19) Step S4, water was added into a reaction vessel, followed by heating to 70° C. to 90° C., and the zinc chloride solution in step S1 and the zinc-ammonia complex solution in step S3 were simultaneously added in a parallel feeding manner, a reaction pH value was maintained at 6.0 to 7.0, and the reaction lasted for 2 to 4 hours to obtain a precipitate and a zinc-containing mother solution; and a basic zinc chloride particulate matter in beige or white was obtained by washing and drying the precipitate.

(20) Specific parameters of each embodiment are shown in Table 1.

(21) TABLE-US-00001 TABLE 1 S1, zinc S2, S3, zinc content ammonia- S2, content in in the nitrogen chloride the zinc content in content in zinc-ammonia chloride the final the final complex S4, stirring solution solution solution solution speed Reaction (g/L) (g/L) (g/L) (g/L) (r/min) duration Embodiment 1 60 140 80 60 1200 2 Embodiment 2 150 140 80 60 1200 2 Embodiment 3 60 170 80 110 1200 2 Embodiment 4 60 140 80 60 1500 2 Embodiment 5 110 155 80 110 1300 4 Embodiment 6 110 155 160 110 1300 4 Embodiment 7 110 155 120 110 1300 4

Embodiment 8

(22) Step S1, a zinc-containing flue dust was used as a raw material, by leaching with acid, and removing impurities, a zinc chloride solution was obtained; water was added to the solution to adjust a zinc concentration to 60 g/L, and a purified zinc chloride solution was obtained;

(23) Step S2, an ammonia solution having a pH of 10 or more was prepared, ammonium chloride was added as an inducer into the ammonia solution to prepare a mixed solution, the ammonium chloride served as a main source of chloride ions in the mixed solution so that the mixed solution had an ammonia-nitrogen concentration of 140 g/L to 170 g/L and a chloride ion concentration of 80 g/L to 160 g/L;

(24) Step S3, the zinc-containing flue dust was added to a mixed solution prepared in step S2 for complexing and ammonia-leaching, when a zinc concentration in the liquid phase reached to 60 g/L, filtering separation was performed, ammonia-leaching of the solid phase was continued, zinc powder was added to the liquid phase for replacement and removal of impurities, and a purified zinc-ammonia complex solution was obtained;

(25) Step S4, synthesis of basic zinc chloride

(26) water was added into a reaction vessel, followed by heating to 70° C., and the purified zinc chloride solution and the zinc-ammonia complex solution were simultaneously added in a parallel feeding manner, a reaction pH value was maintained at 6.0 to 7.0, and the reaction lasted for 2 hours to obtain a precipitate and a zinc-containing mother solution; and a basic zinc chloride particulate matter was obtained by washing and drying the precipitate; and

(27) Step S5, wastewater treatment

(28) sodium hydroxide was added to the zinc-containing mother solution for steam stripping, and gaseous phase was subjected to spraying absorption to recycle ammonia water which can be reused in the production or for sale; solid phase obtained by ammonia distillation of liquid phase was the zinc hydroxide solid which can be returned to the front end and dissolved in the hydrochloric acid to prepare the zinc chloride solution for reuse in the production; after the wastewater rid of ammonia-nitrogen was subjected to depth removal of heavy metals, sodium chloride can be recycled by MVR (mechanical vapor recompression) concentration and crystallization, and the evaporated moisture can be reused in production as recycled water after cooling, without discharge of wastewater.

Comparative Example 1

(29) Basically the same as the above-mentioned Embodiment 1, but a reaction pH value in the synthesis of the basic zinc chloride in step S4 was set as 5.

Comparative Example 2

(30) Basically the same as the above-mentioned Embodiment 1, but a reaction pH value in the synthesis of the basic zinc chloride in step S4 was set as 8.

Comparative Example 3

(31) Basically the same as the above-mentioned Embodiment 1, but a stirring speed in the synthesis of the basic zinc chloride in step S4 was set as 1600 r/min.

Comparative Example 4

(32) Basically the same as the above-mentioned Embodiment 1, but a stirring speed in the synthesis of the basic zinc chloride in step S4 was set as 1100 r/min.

Comparative Example 5

(33) Basically the same as the above-mentioned Embodiment 6, but a chloride ion concentration in the mixed solution obtained in step S2 was 70 g/L.

Comparative Example 6

(34) Basically the same as the above-mentioned Embodiment 6, but a chloride ion concentration in the mixed solution obtained in step S2 was 170 g/L.

(35) The basic zinc chloride particulate matters prepared by each of the embodiments and comparative examples were subjected to the particle size distribution test and flowability test, and the results are as shown in Table 2.

(36) TABLE-US-00002 TABLE 2 Angle of Particle repose of basic size range zinc chloride Basic zinc of basic zinc particulate chloride content chloride D.sub.10 D.sub.95 matter in particulate (μm) (μm) (μm) (degree) Morphology matter (%) Embodiment 1  4~900 106 518 30 Sphere-like 98.5 white particles Embodiment 2 10~880 115 530 32 Sphere-like 98.6 white particles Embodiment 3  8~850 112 550 35 Sphere-like 98.6 white particles Embodiment 4  5~890 118 515 33 Sphere-like 98.6 white particles Embodiment 5 10~810 115 540 35 Sphere-like 98.7 white particles Embodiment 6 15~750 120 579 35 Sphere-like 98.8 white particles Embodiment 7 15~690 118 575 35 Sphere-like 98.8 white particles Embodiment 8  6~800 108 560 31 Sphere-like 98.7 white particles Comparative 1~80 45 78 58 White 96.7 Example 1 powder Comparative 1~90 55 85 65 White 97.5 Example 2 powder Comparative  1~105 62 100 55 White 96.1 Example 3 powder Comparative  1~300 83 288 48 White solid 97.5 Example 4 Comparative  1~120 44 115 52 White 96.2 Example 5 powder Comparative  1~180 52 160 50 White 97.1 Example 6 powder Commercially  1~110 20 100 55~60 Beige 98.1 available basic powder zinc chloride particulate matter

(37) It can be seen from the data of the above-mentioned embodiments and comparative examples that the pH value, the chloride ion content in the ammonia solution and the stirring speed exert a significant effect on the prepared basic zinc chloride particles. The basic zinc chloride particles prepared within the pH value range of the present disclosure have a sphere-like shape, an angle of repose of 30° to 35°, and excellent flowability, which are conducive to storage and uniform mixing of the premix. The basic zinc chloride particles have a D.sub.10 of more than 100 μm and a D.sub.95 of more than 450 μm, indicating that most of them are particles with relatively large particle size, and the particle size is uniform. They are more convenient in use, compared with the commercially available basic zinc chloride product of which the particle size is too small and uneven. It can be seen from the comparative examples that particles with large particle size may also be obtained (for example, Comparative Example 4) even though the preparation process is out of the scope of the present disclosure, but such product still has bad flowability performance and is difficult to be dispersed.

(38) The basic zinc chloride particulate matters prepared by Embodiments 1 to 8 were sieved through a 35-mesh sieve, particles which can pass through the 35-mesh sieve were collected, and D.sub.10 and D.sub.95 thereof were measured. Results are as shown in Table 3.

(39) TABLE-US-00003 TABLE 3 Particle size Angle of range of repose of Basic zinc basic zinc basic zinc chloride Mass Mass chloride chloride content in before after after particulate particulate sieving sieving sieving D.sub.10 D.sub.95 matter matter (g) (g) (μm) (μm) (μm) (degree) Morphology (%) Embodiment 1 200 198.9  4~450 115 488 30 Sphere-like 98.8 white particles Embodiment 2 200 199.3 10~450 115 510 30 Sphere-like 98.6 white particles Embodiment 3 200 199.4  8~450 110 550 35 Sphere-like 98.6 white particles Embodiment 4 200 199.1  5~450 120 485 30 Sphere-like 98.6 white particles Embodiment 5 200 198.4 10~450 125 510 35 Sphere-like 98.7 white particles Embodiment 6 200 198.8 15~450 110 479 35 Sphere-like 98.1 white particles Embodiment 7 200 198.7 15~450 108 475 35 Sphere-like 98.2 white particles Embodiment 8 200 198.5  6~450 117 480 35 Sphere-like 98.7 white particles