阅读说明：本技术 制备高纯碳酸钙的装置及工艺 (Device and process for preparing high-purity calcium carbonate ) 是由 张旭 李传松 于 2019-10-08 设计创作，主要内容包括：本发明公布了一种制备高纯碳酸钙的装置,包括碳化反应槽、蒸馏水收集槽、碳酸钙过滤槽、浸出渣过滤槽、第一离心泵、第二离心泵、水喷射泵、二氧化碳接入口端；碳化反应槽、碳酸钙过滤槽、第一离心泵通过管道构成闭合回路,蒸馏水收集槽、第二离心泵、水喷射泵构成闭合回路,碳酸钙过滤槽、浸出渣过滤槽结构相同,均位于碳化反应槽正上方,均在上方并联连接第一离心泵出液口,均在上方并联连接第二离心泵出液口的一条支路,均在侧面并联连接水喷射泵的气体入口端,均在底部连接碳化反应槽,水喷射泵液体入口端连接第二离心泵出口端另一条支路,气液混合物出口端连接正下方的蒸馏水收集槽,二氧化碳接入口端连接在碳化反应槽上部。(The invention discloses a device for preparing high-purity calcium carbonate, which comprises a carbonization reaction tank, a distilled water collecting tank, a calcium carbonate filter tank, a leaching residue filter tank, a first centrifugal pump, a second centrifugal pump, a water jet pump and a carbon dioxide inlet end; the carbonization reaction tank, the calcium carbonate filter-tank, first centrifugal pump passes through the pipeline and constitutes closed circuit, the distilled water collecting vat, the second centrifugal pump, the water jet pump constitutes closed circuit, the calcium carbonate filter-tank, it is the same to leach the sediment filter-tank structure, all be located directly over the carbonization reaction tank, all at the first centrifugal pump liquid outlet of top parallel connection, all at a branch road of top parallel connection second centrifugal pump liquid outlet, all at the gas entry end of side parallel connection water jet pump, all connect the carbonization reaction tank in the bottom, another branch road of second centrifugal pump exit end is connected to water jet pump liquid entry end, the distilled water collecting vat under the gas-liquid mixture exit end connection, carbon dioxide access port end is connected on carbonization reaction tank upper portion.)

1. A device for preparing high-purity calcium carbonate is characterized by comprising the following structures: a carbonization reaction tank (1), a water collecting tank (2), a calcium carbonate filter tank (3), a leaching residue filter tank (4), a first centrifugal pump (5), a second centrifugal pump (6), a water injection pump (7) and a carbon dioxide inlet end (8); the carbonization reaction tank (1), the calcium carbonate filter tank (3) and the first centrifugal pump (5) form a closed loop through pipelines; the water collecting tank (2), the second centrifugal pump (6) and the water spraying pump (7) form a closed loop; the calcium carbonate filter tank (3) and the leaching residue filter tank (4) are identical in structure, are both positioned right above the carbonization reaction tank (1), are respectively connected with the liquid outlets of the first centrifugal pump (5) at the upper part, are respectively connected with a branch of the liquid outlet of the second centrifugal pump (6) at the upper part, are respectively connected with the gas inlet end of the water jet pump (7) at the side surface, and are respectively connected with the carbonization reaction tank (1) at the bottom; the liquid inlet end of the water jet pump (7) is connected with the other branch of the outlet end of the second centrifugal pump (6), and the outlet end of the gas-liquid mixture is connected with the water collecting tank (2) right below; the carbon dioxide inlet end (8) is connected to the upper part of the carbonization reaction tank; a valve (a) is arranged on a pipeline between the first centrifugal pump (5) and the calcium carbonate filter tank (3), and a valve (c) is arranged on a pipeline between the first centrifugal pump (5) and the leaching residue filter tank (4); a valve (b) is arranged on a pipeline between the second centrifugal pump (6) and the calcium carbonate filter tank (3), a valve (d) is arranged on a pipeline between the second centrifugal pump (6) and the leaching residue filter tank (4), and a valve (g) is arranged on a pipeline between the second centrifugal pump (6) and the water jet pump (7); a valve (e) is arranged on a pipeline between the water injection pump (7) and the calcium carbonate filter tank (3), and a valve (f) is arranged on a pipeline between the water injection pump (7) and the leaching residue filter tank (4).

2. The apparatus for preparing high-purity calcium carbonate according to claim 1, wherein: the carbon dioxide receiving end (8) is of a water injection pump structure, the liquid inlet end is connected with the outlet end of the first centrifugal pump (5), the gas inlet end is connected with a carbon dioxide gas source, and the gas-liquid outlet end is connected with the carbonization reaction tank (1).

3. The apparatus for preparing high-purity calcium carbonate according to claim 1 or 2, wherein: the calcium carbonate filter tank (3) and the leaching residue filter tank (4) both comprise the following structures: a filter cake cylinder (A1), a filtrate cylinder (A2), a vacuumizing gas outlet end (A), a washing water inlet end (B), a leached solid-liquid inlet end (C), a filtrate outlet end (D), a dried filter cake outlet end (E), a filter plate (F) and a stirring device (G); the filter cake cylinder (A1) is arranged right above the filtrate cylinder (A2) and is separated by a filter plate (F); the filter cake filtering device is characterized in that the outlet end (A) is positioned at the upper part of the side face of the filtrate cylinder (A2), the washing water inlet end (B) and the leaching solid-liquid inlet end (C) are positioned at the top of the filter cake cylinder (A1), the filtrate outlet end (D) is positioned at the bottom of the filtrate cylinder (A2), the outlet end (E) is positioned at the lower part of the side face of the filter cake cylinder (A1), and the stirring device (G) is positioned in the middle of the filter cake cylinder (A1).

4. The apparatus for preparing high-purity calcium carbonate according to claim 3, wherein: the calcium carbonate filter tank (3) and the leaching residue filter tank (4) also comprise a water bath heating structure (H1) at the position of the filter cake cylinder (A1) and are positioned at the periphery of the cylinder body.

5. The apparatus for preparing high-purity calcium carbonate according to claim 3, wherein: the calcium carbonate filter tank (3) and the leaching residue filter tank (4) also comprise a water bath heating structure (H2) at the position of the filtrate cylinder (A2) and are positioned at the periphery of the cylinder body.

6. The apparatus for preparing high-purity calcium carbonate according to claim 1, wherein: a water bath temperature control jacket is arranged at the periphery of the water collecting tank (2).

7. A method for preparing high-purity calcium carbonate by using the device of claims 1-6 comprises the following steps:

1) a preparation stage, in which distilled water is added into the water collecting tank (2) in advance;

2) in the leaching stage, ammonium salt solution is added into the carbonization reaction tank (1), and materials containing calcium hydroxide or calcium oxide are added into the carbonization reaction tank (1) and stirred to generate a solid-liquid mixture of soluble calcium salt, ammonia water and solid slag;

3) filtering leached residues, removing impurities, and leaching simultaneously, starting a first centrifugal pump (5), pumping the solid-liquid mixture obtained by leaching in the step 2) into a leached residue filter tank (4), starting a second centrifugal pump (6), vacuumizing the leached residue filter tank (4), performing suction filtration, adding an ammonium salt solution into a carbonization reaction tank (1), adding a material containing calcium hydroxide or calcium oxide into the carbonization reaction tank (1), and stirring to generate a solid-liquid mixture of soluble calcium salt, ammonia water and solid residues;

4) filtering leaching residues, removing impurities, carbonizing, and performing a stage simultaneously, starting a first centrifugal pump (5), pumping the solid-liquid mixture obtained by leaching in the step 3) into a leaching residue filtering tank (4), starting a second centrifugal pump (6), vacuumizing the leaching residue filtering tank (4), performing suction filtration, introducing the calcium salt in the step 3) into a carbonization reaction tank (1), and introducing carbon dioxide to react to obtain a solid-liquid mixture of calcium carbonate and ammonium salt solution;

5) performing calcium carbonate filtration-carbonization at the same time, starting a first centrifugal pump (5), pumping the calcium carbonate and ammonium salt solution obtained in the step 4) into a calcium carbonate filter tank (3), starting a second centrifugal pump (6), vacuumizing and filtering the calcium carbonate filter tank (3), introducing the calcium salt solution obtained in the leaching residue filter tank (4) obtained in the step 4) into a carbonization reaction tank (1), and introducing carbon dioxide for carbonization to obtain calcium carbonate and ammonium salt solution;

6) performing calcium carbonate filtration-leaching simultaneously, starting a first centrifugal pump (5), pumping the calcium carbonate and ammonium salt solution obtained in the step 5) into a calcium carbonate filter tank (3), starting a second centrifugal pump (6), vacuumizing the calcium carbonate filter tank (3), performing suction filtration, introducing the ammonium salt solution obtained in the step 5) into a carbonization reaction tank (1), and adding calcium oxide or calcium hydroxide to obtain a calcium salt solution;

7) repeating the steps 3) -6), entering the next reaction period, and circularly producing calcium carbonate for multiple times;

8) washing and drying the calcium carbonate and the leaching slag and discharging the materials, opening a valve (b) and a valve (d), opening a second centrifugal pump (6), injecting distilled water into the calcium carbonate filter tank (3) and the leaching slag filter tank (4) for washing, closing the valve (b) and the valve (d), vacuumizing and drying the calcium carbonate filter tank (3) and the leaching slag filter tank (4), and discharging the materials.

8. The process for preparing high purity calcium carbonate according to claim 7, wherein the calcium hydroxide is derived from carbide slag.

Technical Field

The invention belongs to the field of chemical machinery, and particularly relates to a device for preparing high-purity calcium carbonate from calcium oxide or calcium hydroxide and a circular production method.

Background

The light calcium carbonate is used as high-quality pigment and filler, and has wide application in the fields of plastics, papermaking, rubber, coating, printing ink, daily chemicals and the like. The purity, whiteness and granularity are important indexes of the light calcium carbonate, and determine the performances such as dispersibility, oil absorption and the like and the application field of the light calcium carbonate, and the high-purity and fine-grained light calcium carbonate is the development trend of the industry.

The process for preparing light calcium carbonate is carried out by calcining limestone, calcite, etc. at high temperature to obtain calcium lime, adding water, digesting, charging carbon dioxide, carbonizing, filtering and drying to obtain target product.

On the other hand, the calcium carbide industry produces a large amount of calcium carbide slag in acetylene gas production, wherein the content of calcium hydroxide can reach 80-90%, and the annual output of the calcium carbide slag in China can reach more than 2000 million tons according to statistics. The carbide slag is strong in alkalinity and can be used for manufacturing cement, flue gas desulfurization and the like, but the utilization rate is still difficult to exceed 30 percent due to huge carbide slag capacity, and most of the carbide slag is buried after anti-seepage treatment, so that mineral resource waste and land resource waste are caused.

It is reported that calcined calcium oxide is used as a raw material, ammonium salt is used for leaching, insoluble impurities are removed by filtration, then carbonization is carried out to obtain calcium carbonate, and the ammonium salt is recycled (Chengming, a circulation method is used for preparing high-purity superfine calcium carbonate [ J ], comprehensive utilization of mineral products is 2004,2:15-17, and US 9725330). The method has high product purity, accords with the green production principle of raw material recycling, but is accompanied with ammonia water generation in the production process, and the ammonia water is easily volatilized and overflows in the processes of filtering, washing and drying calcium carbonate and leaching residue solids, so that adverse effects are generated on the production environment and the ecological environment, and meanwhile, an ammonia still and huge equipment for storing ammonia are required in the common production process, so that the investment is large and the occupied area is large.

Disclosure of Invention

Aiming at the technical defects and imperfections, the invention provides the device for preparing the calcium carbonate and the using method thereof, which can ensure ammonia sealing, prevent air pollution by volatilization, ensure the preparation of the calcium carbonate with fine grain diameter and high purity, and have wide application prospect.

The technical scheme adopted for realizing the purpose is as follows:

a device for preparing high-purity calcium carbonate is characterized by comprising the following structures: the device comprises a carbonization reaction tank, a distilled water collecting tank, a calcium carbonate filter tank, a leaching residue filter tank, a first centrifugal pump, a second centrifugal pump, a water injection pump and a carbon dioxide inlet end; the carbonization reaction tank, the calcium carbonate filter tank and the first centrifugal pump form a closed loop through pipelines; the distilled water collecting tank, the second centrifugal pump and the water spraying pump form a closed loop; the calcium carbonate filter tank and the leaching residue filter tank are of the same structure, are both positioned right above the carbonization reaction tank, are respectively connected with a liquid outlet of a first centrifugal pump at the upper part, are respectively connected with a branch of a liquid outlet of a second centrifugal pump at the upper part, are respectively connected with a gas inlet end of a water injection pump at the side surface, and are respectively connected with the carbonization reaction tank at the bottom; the liquid inlet end of the water jet pump is connected with the other branch of the outlet end of the second centrifugal pump, and the outlet end of the gas-liquid mixture is connected with a distilled water collecting tank right below; the carbon dioxide inlet end is connected to the upper part of the carbonization reaction tank; a valve a is arranged on a pipeline between the first centrifugal pump and the calcium carbonate filter tank, and a valve c is arranged on a pipeline between the first centrifugal pump and the leaching residue filter tank; a valve b is arranged on a pipeline between the second centrifugal pump and the calcium carbonate filter tank, a valve d is arranged on a pipeline between the second centrifugal pump and the leaching residue filter tank, and a valve g is arranged on a pipeline between the second centrifugal pump and the water jet pump; and a valve e is arranged on a pipeline between the water injection pump and the calcium carbonate filter tank, and a valve f is arranged on a pipeline between the water injection pump and the leaching residue filter tank.

Preferably, the carbon dioxide receiving end is of a water jet pump structure, the liquid inlet end is connected with the outlet end of the first centrifugal pump, the gas inlet end is connected with a carbon dioxide gas source, and the gas-liquid outlet end is connected with the carbonization reaction tank, so that gas-liquid mixing can be promoted, and the carbon dioxide absorption efficiency is high.

In the technical scheme, the calcium carbonate filter tank and the leaching residue filter tank both comprise the following structures: a filter cake cylinder, a filtrate cylinder, a vacuum-pumping gas outlet end, a washing water inlet end, a leaching solid-liquid inlet end, a filtrate outlet end, a dried filter cake outlet end, a filter plate and a stirring device; the filter cake cylinder is arranged right above the filtrate cylinder and is separated by a filter plate; the outlet end is positioned at the upper part of the side surface of the filtrate cylinder, the washing water inlet end and the leaching solid-liquid inlet end are positioned at the top of the filter cake cylinder, the filtrate outlet end is positioned at the bottom of the filtrate cylinder, the outlet end is positioned at the lower part of the side surface of the filter cake cylinder, and the stirring device is positioned in the middle of the filter cake cylinder. The exit end is the material exit end after the drying, and the filter divides into two parts about the cartridge filter, and lower part is used for temporary storage filtrating, and the upper portion is used for filtering, washing, drying and temporary storage filter cake, and agitating unit is used for mixing the filter cake, promotes to filter, and dry and solid material discharge.

In the technical scheme, the calcium carbonate filter tank and the leaching residue filter tank also comprise a water bath heating structure at the position of the filtrate cylinder, and are positioned at the periphery of the cylinder body, and the water bath heating structure can promote the drying of calcium carbonate or leaching residue, thereby improving the production rate.

In the technical scheme, the calcium carbonate filter tank and the leaching residue filter tank further comprise a water bath heating structure at the position of the filtrate cylinder, the water bath heating structure is positioned at the periphery of the cylinder, and the water bath heating structure promotes the water in the filter tank to evaporate and enter the water collecting tank, so that the water balance of the water tank is ensured.

In the technical scheme, the periphery of the water collecting tank is also provided with a water bath temperature control jacket, so that the capacity of generating negative pressure by the water jet pump can be improved by heating or cooling, and the solubility of ammonia in the water tank can be reduced.

The method for preparing the high-purity calcium carbonate by adopting the device comprises the following steps:

1) a preparation stage, in which distilled water is added in advance into the water collecting tank 2;

2) in the leaching stage, ammonium salt solution is added into the carbonization reaction tank 1, and materials containing calcium hydroxide or calcium oxide are added into the carbonization reaction tank 1 and stirred to generate a solid-liquid mixture of soluble calcium salt, ammonia water and solid slag;

3) filtering leached residues, removing impurities, and leaching simultaneously, starting a first centrifugal pump 5, pumping the solid-liquid mixture obtained by leaching in the step 2) into a leached residue filter tank 4, starting a second centrifugal pump 6, vacuumizing and filtering the leached residue filter tank 4, adding an ammonium salt solution into a carbonization reaction tank 1, adding a material containing calcium hydroxide or calcium oxide into the carbonization reaction tank 1, and stirring to generate a solid-liquid mixture of soluble calcium salt, ammonia water and solid residues;

4) filtering leached residues, removing impurities, carbonizing and simultaneously carrying out a stage, starting a first centrifugal pump 5, pumping the solid-liquid mixture obtained by leaching in the step 3) into a leached residue filter tank 4, starting a second centrifugal pump 6, vacuumizing the leached residue filter tank 4, carrying out suction filtration, introducing the calcium salt in the step 3) into a carbonization reaction tank 1, and introducing carbon dioxide to react to obtain a solid-liquid mixture of calcium carbonate and ammonium salt solution;

5) performing calcium carbonate filtration-carbonization at the same time, starting a first centrifugal pump 5, pumping the calcium carbonate and ammonium salt solution obtained in the step 4) into a calcium carbonate filter tank 3, starting a second centrifugal pump 6, vacuumizing and filtering the calcium carbonate filter tank 3, introducing the calcium salt solution obtained in the leaching residue filter tank 4 in the step 4) into a carbonization reaction tank 1, and introducing carbon dioxide for carbonization to obtain calcium carbonate and ammonium salt solution;

6) performing calcium carbonate filtration-leaching simultaneously, starting a first centrifugal pump 5, pumping the calcium carbonate and ammonium salt solution obtained in the step 5) into a calcium carbonate filter tank 3, starting a second centrifugal pump 6, vacuumizing and filtering the calcium carbonate filter tank 3, introducing the ammonium salt solution obtained in the step 5) into a carbonization reaction tank 1, and adding calcium oxide or calcium hydroxide to obtain a calcium salt solution;

7) repeating the steps 3) -6), entering the next reaction period, and circularly producing calcium carbonate for multiple times;

8) washing and drying the calcium carbonate and the leaching slag and discharging the materials, opening a valve b and a valve d, opening a second centrifugal pump 6, injecting distilled water into a calcium carbonate filter tank 3 and a leaching slag filter tank 4 for washing, closing the valve b and the valve d, vacuumizing and drying the calcium carbonate filter tank 3 and the leaching slag filter tank 4, and discharging the materials.

In the scheme, the calcium hydroxide can be the carbide slag with wide sources, and the carbide slag waste is recycled to produce the calcium carbonate, so that the method has considerable environmental protection benefits and economic benefits.

The principle of the invention comprises:

calcium hydroxide is obtained by reacting calcium oxide with water or is directly reacted with ammonium salt by taking the calcium hydroxide as a raw material:

Ca(OH)₂+2NH₄ ⁺＝Ca²⁺+2NH₃·H₂O

after calcium ions are selectively leached, the aim of removing impurities is achieved by filtering.

And (3) reacting the calcium salt solution after impurity removal with ammonia water and carbon dioxide to obtain calcium carbonate:

Ca²⁺+2NH₃·H₂O+CO₂＝CaCO₃↓+2NH₄ ⁺+2H₂O

filtering, washing and drying in the device to obtain the product with high purity and fine particle size.

Therefore, the device has the functions of impurity removal, reaction, filtration, washing and drying, does not depend on additional washing water, can prevent ammonia from overflowing, and is convenient and clean to produce.

The invention has the beneficial effects that: 1) ammonia and ammonium salt are recycled in the process, actual consumption is avoided, and cost is reduced; 2) the calcium carbonate product has high purity, fine particle size and wide application potential; 3) the operation under the sealing condition prevents ammonia gas from overflowing and protects the environment; 4) the reaction, the filtration, the washing and the drying can be carried out in the same device, so that the reaction, the filtration, the washing and the drying are convenient and fast, and the product transfer pollution is avoided; 5) the device has high utilization rate, and in the cycle operation, the ammonium salt leaching, the leaching residue filtering, the calcium salt carbonization and the calcium carbonate filtering are alternately carried out, the device is not stopped, and the yield can be maximized.

Drawings

FIG. 1 is a diagram of an apparatus for producing calcium carbonate according to the present invention.

FIG. 2 is a view showing the calcium carbonate filter tank or the leaching residue filter tank according to the present invention.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.