Preparation method of light spherical calcium carbonate

Abstract

The invention discloses a preparation method of light spherical calcium carbonate, which comprises the following steps: 1, adding boric acid into water for dissolving, and uniformly stirring on a stirrer to obtain a boric acid solution as a crystal form control agent; 2, calcium chloride is added into water to be dissolved, and a calcium chloride solution is obtained; 3, sodium carbonate is added into water to be dissolved, and a sodium carbonate solution is obtained; 4, adding the boric acid solution into the calcium chloride solution, and uniformly stirring on a stirrer to obtain a mixed solution; 5, dropwise adding the sodium carbonate solution into the mixed solution, controlling the solution to be under an alkaline condition, and reacting sodium carbonate with calcium chloride to obtain a calcite type spherical calcium carbonate crystal solution; and 6, aging the calcite type spherical calcium carbonate crystal solution to obtain a calcite type spherical calcium carbonate crystal precipitate. In the presence of the boric acid control agent, reactants are subjected to liquid-phase ion exchange precipitation reaction to prepare the light spherical calcium carbonate with stable form and uniform particle size.

Description

Technical Field

[0001] The present invention relates to the technical field of light spherical calcium carbonate production, and particularly relates to a preparation method of light spherical calcium carbonate. Background Art

[0002] Light spherical calcium carbonate has the advantages of large specific surface area, good dispersion, fluidity and solubility, and has important applications in the fields of papermaking, plastics, electronics, ink and ceramics. Currently, the commonly used preparation methods of spherical calcium carbonate include carbonization method, microemulsion method, simulated biomineralization method and double decomposition method, which have the deficiencies of difficult reaction condition control, low yield and high cost. Among them, the carbonization method needs to control a series of influencing factors such as the gas ratio and the gas addition method during the reaction process, and the operation is complex and difficult to control. The microemulsion method needs to prepare microemulsion and makes the crystallization reaction of calcium carbonate proceed inside the microemulsion droplets, which is not suitable for large-scale industrial production. Therefore, in order to avoid the disadvantages existing in the prior art, it is necessary to improve the prior art. Summary of the Invention

[0003] The purpose of the present invention is to overcome the disadvantages and deficiencies in the prior art, and provide a preparation method of light spherical calcium carbonate with easy reaction condition control and high yield.

[0004] The present invention is realized by the following technical solutions:

[0005] A preparation method of light spherical calcium carbonate, comprising the following steps,

[0006] Step 1: Add boric acid to water and dissolve it, stir evenly on a stirrer to obtain a boric acid solution as a crystal form control agent;

[0007] Step 2: Add calcium chloride to water and dissolve it, stir evenly on a stirrer to obtain a calcium chloride solution;

[0008] Step 3: Add sodium carbonate to water and dissolve it, stir evenly on a stirrer to obtain a sodium carbonate solution;

[0009] Step 4: Add the boric acid solution to the calcium chloride solution, stir evenly on a stirrer to obtain a mixed solution;

[0010] Step 5: Drop the sodium carbonate solution into the mixed solution, control the solution under alkaline conditions, and react sodium carbonate with calcium chloride to obtain a calcite-type spherical calcium carbonate crystal solution;

[0011] Step 6: Age the calcite-type spherical calcium carbonate crystal solution to obtain a calcite-type spherical calcium carbonate crystal precipitate;

[0012] Step 7: Evaporate the calcite-type spherical calcium carbonate crystal solution to remove water, screen the calcite-type spherical calcium carbonate crystal precipitate, and then obtain light spherical calcium carbonate through drying, pulverization, and screening.

[0013] Further, in the said Step 1, the pH value of the boric acid solution is 5.5 - 6.

[0014] Further, in the said Step 5, the concentration of boric acid is 0.3 mol / L - 0.5 mol / L.

[0015] Further, in the said Step 5, the sodium carbonate solution is a saturated sodium carbonate solution, and the dropping rate of the sodium carbonate solution is 4.7 mL / min - 5.1 mL / min.

[0016] Further, in the said Step 5, the concentrations of both the calcium chloride solution and the sodium carbonate solution are 0.08 mol / L - 0.12 mol / L.

[0017] Further, in the said Step 5, the reaction time is 50 min - 70 min.

[0018] Further, in the said Step 6, the aging time is 50 min - 70 min.

[0019] Further, in the said Step 5, the reaction temperature is 40°C - 60°C.

[0020] Further, in the said Step 5, the molar ratio of calcium chloride to sodium carbonate is 1:1.

[0021] Further, in the said Step 5, the temperature of the sodium carbonate solution is 15°C - 25°C.

[0022] Compared with the prior art, the present invention uses boric acid as a crystal form control agent, calcium chloride and sodium carbonate as raw materials, draws on the control effect of crystal form and morphology in the biomineralization method, and adopts a liquid-phase ion exchange reaction to prepare calcite-type spherical calcium carbonate crystals. In the presence of the boric acid control agent, the reactants are subjected to a liquid-phase ion exchange precipitation reaction to prepare light spherical calcium carbonate with stable morphology and uniform particle size. It has the advantages of easy control of reaction conditions, high yield, and low cost, and has great significance in reducing the cost of preparing light calcium carbonate and maintaining industrial advantages, and is suitable for industrial production. Specific Embodiments

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] A preparation method of light spherical calcium carbonate, comprising the following steps,

[0025] Step 1: Add boric acid to water and dissolve it, stir evenly on a stirrer to obtain a boric acid solution as a crystal form control agent;

[0026] Step 2: Add calcium chloride to water and dissolve it, stir evenly on a stirrer to obtain a calcium chloride solution;

[0027] Step 3: Add sodium carbonate to water and dissolve it, stir evenly on a stirrer to obtain a sodium carbonate solution;

[0028] Step 4: Add the boric acid solution to the calcium chloride solution, stir evenly on a stirrer to obtain a mixed solution;

[0029] Step 5: Drop the sodium carbonate solution into the mixed solution, control the solution under alkaline conditions, and react sodium carbonate with calcium chloride to obtain a calcite-type spherical calcium carbonate crystal solution;

[0030] Step 6: Age the calcite-type spherical calcium carbonate crystal solution to obtain a calcite-type spherical calcium carbonate crystal precipitate;

[0031] Step 7: Evaporate and remove the water from the calcite-type spherical calcium carbonate crystal solution, sieve the calcite-type spherical calcium carbonate crystal precipitate, and then obtain light spherical calcium carbonate through drying, pulverizing, and sieving.

[0032] By using boric acid as a crystal form control agent, calcium chloride and sodium carbonate as raw materials, drawing on the control effect of crystal form and morphology in the biomineralization method, and adopting a liquid-phase ion exchange reaction, calcite-type spherical calcium carbonate crystals are prepared. In the presence of a boric acid control agent, a liquid-phase ion exchange precipitation reaction is carried out on the reactants to prepare light spherical calcium carbonate with stable morphology and uniform particle size. The reaction conditions are easy to control, the yield is high, and the cost is low. It has great significance in reducing the cost of preparing light calcium carbonate and maintaining industrial advantages, and is suitable for industrial production.

[0033] In Step 1, the pH value of the boric acid solution is 5.5 - 6, and the boric acid solution is controlled to be close to or in a saturated state, which is conducive to the subsequent neutralization reaction with the sodium carbonate solution and controls the reaction of sodium carbonate with calcium chloride under alkaline conditions.

[0034] In Step 5, the concentration of boric acid is 0.3 mol / L - 0.5 mol / L, which is more conducive to maintaining a stable neutralization reaction with the sodium carbonate solution and ensuring the stability of the reaction between sodium carbonate and calcium chloride.

[0035] In Step 5, the sodium carbonate solution is a saturated sodium carbonate solution, and the dropping rate of the sodium carbonate solution is 4.7 mL / min - 5.1 mL / min, which is more conducive to controlling the stability of the reaction between sodium carbonate and calcium chloride.

[0036] In Step 5, the concentrations of both the calcium chloride solution and the sodium carbonate solution are 0.08 mol / L to 0.12 mol / L to ensure the sufficiency of the reaction between sodium carbonate and calcium chloride.

[0037] In Step 5, the reaction time is 50 min to 70 min to ensure the sufficiency of the reaction between sodium carbonate and calcium chloride.

[0038] In Step 6, the aging time is 50 min to 70 min to ensure the sufficient aging of the calcite-type spherical calcium carbonate crystal precipitate and improve the stability after formation.

[0039] In Step 5, the reaction temperature is 40°C to 60°C to ensure the rapid reaction between sodium carbonate and calcium chloride and improve the productivity.

[0040] In Step 5, the molar ratio of calcium chloride to sodium carbonate is 1:1 to improve the utilization rate of raw materials, reduce production costs, and at the same time ensure the sufficient reaction between sodium carbonate and calcium chloride.

[0041] In Step 5, the temperature of the sodium carbonate solution is 15°C to 25°C to ensure that the sodium carbonate solution is in a saturated state under natural conditions.

[0042] The results show that when the concentration of boric acid is 0.4 mol / L, the dropping rate of the saturated sodium carbonate solution at 20°C is 4.9 mL / min, the concentration of the reactants is 0.1 mol / L, the reaction time and the aging time are both 60 min, the reaction temperature is 50°C, and the ratio of the reactants is 1:1, the obtained spherical calcium carbonate particles are of uniform size, the particle size is the smallest, and the average particle size is 1.57 μm.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of light spherical calcium carbonate, characterized in that: It includes the following steps: Step 1: Add boric acid to water and dissolve it, stir evenly on a stirrer to obtain a boric acid solution, which serves as a crystal form control agent; Step 2: Add calcium chloride to water and dissolve it, stir evenly on a stirrer to obtain a calcium chloride solution; Step 3: Add sodium carbonate to water and dissolve it, stir evenly on a stirrer to obtain a sodium carbonate solution; Step 4: Add the boric acid solution to the calcium chloride solution and stir evenly on a stirrer to obtain a mixed solution; Step 5: Drop the sodium carbonate solution into the mixed solution, control the solution under alkaline conditions, and react sodium carbonate with calcium chloride to obtain a calcite-type spherical calcium carbonate crystal solution; Step 6: Age the calcite-type spherical calcium carbonate crystal solution to obtain a calcite-type spherical calcium carbonate crystal precipitate; Step 7: Evaporate and remove the water from the calcite-type spherical calcium carbonate crystal solution, screen the calcite-type spherical calcium carbonate crystal precipitate, and then obtain light spherical calcium carbonate through drying, pulverizing, and screening.

2. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 1, the pH value of the boric acid solution is 5.5 - 6.

3. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the concentration of boric acid is 0.3mol / L - 0.5mol / L.

4. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the sodium carbonate solution is a saturated sodium carbonate solution, and the dropping rate of the sodium carbonate solution is 4.7mL / min - 5.1mL / min.

5. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the concentrations of both the calcium chloride solution and the sodium carbonate solution are 0.08mol / L - 0.12mol / L.

6. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the reaction time is 50min - 70min.

7. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 6, the aging time is 50min - 70min.

8. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the reaction temperature is 40°C - 60°C.

9. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the molar ratio of calcium chloride to sodium carbonate is 1:

1.

10. The preparation method of the light spherical calcium carbonate according to claim 1, characterized in that: In the said Step 5, the temperature of the sodium carbonate solution is 15°C - 25°C.