Iron and boron removal device in magnesium chloride production

Abstract

The utility model belongs to the technical field of chemical equipment, and discloses an iron and boron removal device in magnesium chloride production, which comprises a dissolving kettle, an impurity removal kettle, a heat preservation sedimentation kettle, a first filtering device, an acid adjusting kettle, an iron and boron removal kettle, a second filtering device, a concentration kettle, a crystallization kettle, a centrifugal machine, a drying machine and a packaging machine which are sequentially communicated through pipelines, adjusting valves and pumps, the dissolving kettle is provided with a magnesium chloride crude product feeding hole and a water feeding hole; a liquid material outlet of the first filtering device is communicated to a feeding hole of the acid adjusting kettle, the iron and boron removing kettle is provided with a hydrogen peroxide feeding hole and a ferric hydroxide feeding hole, and a liquid material outlet of the second filtering device is communicated to a feeding hole of the concentration kettle; and a liquid material outlet of the centrifugal machine is communicated with a water feeding hole of the dissolving kettle through a pipeline. According to the device, iron and boron elements in the magnesium chloride crude product are removed, the treatment effect is good, the purity of the obtained product is high, and the application range is wide.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment, and particularly relates to a device for removing iron and boron in the production of magnesium chloride. Background Art

[0002] The chemical formula of magnesium chloride is MgCl₂, which is a colorless and deliquescent crystal, usually with 6 molecules of crystal water. Magnesium chloride in China has the characteristics of large reserves, high grade, complete types, relatively concentrated distribution, good resource combination, etc., and has broad development prospects; the developed magnesium chloride can be widely used in the fields of agriculture, industry and medicine. However, except for some magnesium chloride products with low quality requirements for agricultural and industrial needs, the quality requirements for magnesium chloride products in other fields are relatively high. For example, in the electrolytic magnesium industry and medicinal magnesium chloride products, there are certain requirements for purity. For example, in the electrolytic magnesium industry, the requirements for iron ions and boron compounds must be lower than a certain content; in the preparation process of medicinal magnesium chloride, because the pH value needs to be controlled, hydrochloric acid is used for adjustment in the production process. The long-term contact between acidic substances and metal reaction kettles and pipelines will form iron ions and enter the product. Although there is a second filtration process later, ferrous ions are in a soluble state and cannot be removed by filtration. In addition, some other elements, such as boron compounds, also exist in trace amounts, and these all need to be further removed to improve the product purity and ensure that the product quality meets the standards required by customers. Summary of the Invention

[0003] The technical problem to be solved by the utility model is to provide a device for removing iron and boron in the production of magnesium chloride, which overcomes the defects of the prior art, removes iron and boron elements in the crude magnesium chloride product, has good treatment effect, and the obtained product has high purity and wide application range.

[0004] To solve the above technical problem, the technical solution of the utility model is as follows:

[0005] A device for removing iron and boron in the production of magnesium chloride includes a dissolution kettle, an impurity removal kettle, a heat preservation settling kettle, a first filtration device, an acid adjustment kettle, an iron and boron removal kettle, a second filtration device, a concentration kettle, a crystallization kettle, a centrifuge, a dryer and a packaging machine, which are connected in sequence through pipelines, regulating valves and pumps; the dissolution kettle is provided with a crude magnesium chloride feed inlet and a water feed inlet; the liquid material outlet of the first filtration device is connected to the feed inlet of the acid adjustment kettle, the iron and boron removal kettle is provided with a hydrogen peroxide feed inlet and a ferric hydroxide feed inlet, and the liquid material outlet of the second filtration device is connected to the feed inlet of the concentration kettle; the liquid material outlet of the centrifuge is connected to the water feed inlet of the dissolution kettle through a pipeline.

[0006] Preferably, the crude magnesium chloride feed inlet of the dissolution kettle is connected to a crude magnesium chloride storage tank through a pipeline, and the water feed inlet is connected to a water storage tank and the liquid material outlet of the centrifuge through pipelines, regulating valves and pumps respectively.

[0007] Preferably, the acid - adjusting kettle is provided with a hydrochloric acid inlet, and the hydrochloric acid inlet is connected to a hydrochloric acid storage tank through a pipeline, a regulating valve and a pump.

[0008] Preferably, the hydrogen peroxide inlet of the iron - and - boron - removing kettle is connected to a hydrogen peroxide storage tank through a pipeline, a regulating valve and a pump, and the ferric hydroxide inlet is connected to a ferric hydroxide storage tank through a pipeline.

[0009] Preferably, both the first filtering device and the second filtering device are GLT solution filters.

[0010] Due to the adoption of the above - mentioned technical solution, the beneficial effects of the present utility model are as follows:

[0011] By adding an iron - and - boron - removing kettle between the acid - adjusting kettle and the second filtering device, the present utility model conducts a second elimination of iron and boron elements that are not completely eliminated after the first filtration and iron ions generated by the erosion of the acid solution on the reaction kettle wall and pipeline during acid adjustment. In the elimination process, hydrogen peroxide is used to form ferric hydroxide flocculants with divalent iron ions in the material. At the same time, by adding ferric hydroxide additionally, the formed flocculants adsorb boron compounds and then settle together. Finally, through filtration and separation, the effect of eliminating iron and boron elements in the material is achieved. After the above treatment, the iron content can be reduced to less than 20 ppm and the boron content can be reduced to less than 10 ppm.

[0012] In summary, the present utility model removes iron and boron elements in the crude magnesium chloride product, has a good treatment effect, and the obtained product has high purity and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present utility model will be further described below with reference to the drawings and embodiments.

[0014] Figure 1 is a schematic flow chart of an embodiment of the present utility model; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present utility model will be further elaborated below with reference to the drawings and embodiments.

[0016] As Figure 1 shown, the present utility model is an iron - and - boron - removing device in magnesium chloride production, including a dissolution kettle, an impurity - removing kettle, a heat - preservation sedimentation kettle, a first filtering device, an acid - adjusting kettle, an iron - and - boron - removing kettle, a second filtering device, a concentration kettle, a crystallization kettle, a centrifuge, a dryer and a packaging machine that are connected in sequence through pipelines, regulating valves and pumps; the dissolution kettle is provided with a crude magnesium chloride feed inlet and a water feed inlet; the liquid material outlet of the first filtering device is connected to the feed inlet of the acid - adjusting kettle, the iron - and - boron - removing kettle is provided with a hydrogen peroxide inlet and a ferric hydroxide inlet, the liquid material outlet of the second filtering device is connected to the feed inlet of the concentration kettle; the liquid material outlet of the centrifuge is connected to the water feed inlet of the dissolution kettle through a pipeline.

[0017] In actual production, the crude magnesium chloride obtained from the previous process is first dissolved in water, and then the dissolved crude magnesium chloride is transported to an impurity removal kettle for impurity removal. After the material after impurity removal is settled in a heat preservation settling kettle, most of the impurities are settled and separated, and then it enters a first filtering device for filtration to further remove impurities. Then the filtered clear liquid is transported to an acid adjustment kettle to add hydrochloric acid to adjust the pH value. During this process, due to the action of hydrochloric acid, the iron ion content in the material increases. Coupled with the iron ions and other compounds (such as boron) that were not removed during the previous impurity removal process, the purity of magnesium chloride in the material is still relatively low and cannot meet the requirements of high-purity products. Therefore, further removal is needed. The material after acid adjustment is transported to an iron and boron removal kettle, and a certain amount of hydrogen peroxide is added according to the detected impurity content results to oxidize the iron ions to obtain iron hydroxide flocculates. At the same time, additional external iron hydroxide is added to make the iron hydroxide content in the material reach a certain level, and the formed flocculates can adsorb impurities in the material, such as boron compounds. After the reaction is completed, the material is transported to a second filtering device for filtration to filter out impurities such as iron hydroxide flocculates and the adsorbed boron compounds, and the clear liquid is transported to a concentration kettle for concentration, crystallization, separation, and drying to obtain high-purity magnesium chloride products.

[0018] It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. An iron and boron removal device in magnesium chloride production, characterized in that: It includes a dissolving kettle, an impurity-removing kettle, a heat-preserving sedimentation kettle, a first filtering device, an acid-adjusting kettle, an iron-boron removing kettle, a second filtering device, a concentrating kettle, a crystallization kettle, a centrifuge, a dryer and a packaging machine which are connected in sequence through pipelines, regulating valves and pumps; the dissolving kettle is provided with a crude magnesium chloride feed inlet and a water feed inlet; the liquid material outlet of the first filtering device is connected to the feed inlet of the acid-adjusting kettle, the iron-boron removing kettle is provided with a hydrogen peroxide feed inlet and a ferric hydroxide feed inlet, and the liquid material outlet of the second filtering device is connected to the feed inlet of the concentrating kettle; the liquid material outlet of the centrifuge is connected to the water feed inlet of the dissolving kettle through a pipeline.

2. The iron and boron removal device in the production of magnesium chloride according to claim 1, characterized in that: The crude magnesium chloride feed inlet of the dissolving kettle is connected to a crude magnesium chloride storage tank through a pipeline, and the water feed inlet is connected to a water storage tank and the liquid material outlet of the centrifuge respectively through pipelines, regulating valves and pumps.

3. The iron and boron removal device in the production of magnesium chloride according to claim 1, characterized in that: The acid-adjusting kettle is provided with a hydrochloric acid feed inlet, and the hydrochloric acid feed inlet is connected to a hydrochloric acid storage tank through pipelines, regulating valves and pumps.

4. The iron and boron removal device in magnesium chloride production according to claim 1, characterized in that: The hydrogen peroxide feed inlet of the iron-boron removing kettle is connected to a hydrogen peroxide storage tank through pipelines, regulating valves and pumps, and the ferric hydroxide feed inlet is connected to a ferric hydroxide storage tank through a pipeline.

5. The iron and boron removal device in the production of magnesium chloride according to claim 1, characterized in that: Both the first filtering device and the second filtering device are GLT solution filters.

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