Production device of anhydrous magnesium chloride

Abstract

The utility model relates to a production device of anhydrous magnesium chloride, and belongs to the technical field of magnesium chloride industrial production. The production device comprises a fluidized bed, an HCl gas heating device and a tail gas treatment system, a feeding pipe is arranged on the bottom side of the feeding end of the fluidized bed, a material returning opening is formed in the top of the feeding end of the fluidized bed, a plurality of atomizing nozzles are arranged on the inner side section of the fluidized bed of the feeding pipe, the feeding end of the feeding pipe is connected with a high-concentration magnesium chloride solution input device, and the high-concentration magnesium chloride solution input device is connected with the tail gas treatment system. The HCl gas heating device pipeline is butted with an air inlet in the bottom side of the fluidized bed, and the tail gas treatment system pipeline is butted with an air outlet in the top of the fluidized bed. According to the anhydrous magnesium chloride production device designed by the utility model, anhydrous magnesium chloride can be directly produced from a magnesium chloride solution in one drying device, so that the process flow is shortened, and the energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial production of anhydrous magnesium chloride, in particular to a production device of anhydrous magnesium chloride. Background Art

[0002] Magnesium is a very important metal material in modern industry and is widely used in various fields. Anhydrous magnesium chloride is the main raw material for the electrolytic production of magnesium metal. At present, the mature magnesium chloride granulation process at home and abroad is mainly Hydro's rotary centrifugal basket granulation technology, but there are many restrictive problems in the actual operation of this process: such as the mesh is easy to clog and wear, the rotating parts are frequently damaged, and it is impossible to ensure long-term continuous operation. The equipment is large and expensive. Multi-step dehydration to prepare anhydrous magnesium chloride is also a widely used production process, but the multi-step dehydration process to prepare anhydrous magnesium chloride needs to be carried out in a multi-stage drying device (such as a fluidized bed). First, the granulation of magnesium chloride is completed by a granulation device to generate hexahydrate magnesium chloride from a magnesium chloride solution, and then the hexahydrate magnesium chloride is dehydrated to generate dihydrate magnesium chloride by a primary drying device, and finally the dihydrate magnesium chloride is used to generate anhydrous magnesium chloride by a secondary drying device. The whole production line has unfavorable factors such as high energy consumption and no energy saving. The overall process flow is long, and the cost of device investment, operation and maintenance is also very high. In addition, the long process flow and the errors in the engineering design of each process stage lead to unreasonable system matching and too high ineffective losses, resulting in the current high production cost of anhydrous magnesium chloride. Utility Model Content

[0003] In order to solve the problems in the prior art, the utility model patent designs a production device for anhydrous magnesium chloride, which integrates the complete dehydration and granulation of magnesium chloride and completes them at one time in one device, thereby reducing the investment in production equipment and the operating energy consumption, so as to solve the problems of large investment and high energy consumption of the existing anhydrous magnesium chloride production device.

[0004] The technical solution adopted by the utility model is as follows: the production device comprises a fluidized bed, an HCl gas heating device and an exhaust gas treatment system; a feed pipe is arranged at the bottom side of the feed end of the fluidized bed, a return port is arranged at the top, a plurality of atomizing nozzles are arranged on the feed pipe, the HCl gas heating device is connected to the air inlet at the bottom side of the fluidized bed, and the exhaust gas treatment system is connected to the exhaust port at the top of the fluidized bed.

[0005] Furthermore, the tail gas treatment system includes a quencher, a washing tower, a dehumidification device and a circulating fan which are sequentially connected by pipelines, the air inlet end of the quencher is connected to the exhaust port of the fluidized bed, and the air outlet end of the circulating fan is connected to the HCl gas heating device.

[0006] Furthermore, the feed pipe is a double-layer sleeve, the gas path and the liquid path inside the atomizing nozzle are respectively connected to the double-layer sleeve of the feed pipe, and the outer ends of the double-layer sleeve are respectively connected to the pressurized feed pipeline and the high-pressure gas source.

[0007] Furthermore, the washing tower is provided with a circulating spray device, which includes a circulating pump, a circulating pipeline and multiple spray heads. The liquid inlet end of the circulating pump is connected to the liquid inlet pipeline through a three-way valve, and the liquid outlet end of the circulating pump is connected to the external transmission pipeline through a three-way valve.

[0008] Furthermore, the dehumidification device includes a heat exchanger and a condenser connected in sequence, and the liquid outlet ends of the heat exchanger and the condenser are connected to a condensed water collection pipeline, and the condensed water collection pipeline is connected to a hydrochloric acid analysis device.

[0009] Furthermore, the heat exchange pipelines of the heat exchanger and the quench cooler are connected in series, and the coolant first flows through the heat exchanger and then through the quench cooler.

[0010] Furthermore, a sifter is connected to the discharge end of the fluidized bed, and unqualified materials from the sifter are connected to the return port of the fluidized bed through a return conveying mechanism.

[0011] Furthermore, the tail gas treatment system is further provided with an HCl preheater upstream of the circulating fan.

[0012] Furthermore, the HCl gas heating device is a gas-fired heating furnace, and the temperature of the HCl gas outlet of the gas-fired heating furnace is maintained at 300°C.

[0013] Compared with the prior art, the advances of the anhydrous magnesium chloride production device designed by the utility model patent are:

[0014] First, the utility model adopts a high-concentration magnesium chloride solution (50% concentration) to be sprayed into the fluidized bed through an atomizing nozzle. The high-concentration magnesium chloride solution is quickly dehydrated under the action of high-temperature HCl hot air at about 300°C to become anhydrous magnesium chloride and coated on the surface of the seed crystal, omitting the step-by-step drying process of magnesium chloride hexahydrate, magnesium chloride tetrahydrate, and magnesium chloride dihydrate in the traditional preparation process, shortening the process flow, and completing the process of preparing anhydrous magnesium chloride in the entire production device in one device, realizing the integration of dehydration and granulation of magnesium chloride, reducing the equipment operation consumption in the intermediate process, and reducing energy loss. At the same time, the appearance of basic magnesium chloride in the drying process of magnesium chloride is effectively avoided, and the quality of the product is improved.

[0015] Second, the utility model realizes the recycling of HCl gas, avoids environmental pollution, and has good economic efficiency.

[0016] Third, the washing tower of the tail gas treatment system of the utility model washes and absorbs the magnesium chloride dust entrained in the tail gas, and the washing liquid with increased concentration after spraying is sent to the evaporation concentration device to prepare a high-concentration magnesium chloride solution, thereby realizing the simultaneous washing of tail gas and material recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a production device for anhydrous magnesium chloride.

[0018] In the figure, 1 is a fluidized bed, 2 is a high-concentration magnesium chloride solution storage tank and a pumping system, 3 is a quencher, 4 is a washing tower, 5 is a heat exchanger, 6 is a condenser, 7 is a preheater, 8 is a circulating fan, 9 is a gas heater, 10 is a screener, 11 is a feed pipe, 12 is an atomizing nozzle, 13 is a hydrochloric acid analysis device, 14 is a return material conveying mechanism, and 41 is a circulating spraying device. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the utility model are clearly and completely described, and the described embodiments are only embodiments of a part of the utility model patent, not all of them. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] like Figure 1 As shown, the utility model patent designs an embodiment of an anhydrous magnesium chloride production device, and the anhydrous magnesium chloride production device in this embodiment includes a fluidized bed 1, an HCl gas heater 9 and an exhaust gas treatment system. A feed pipe 11 is arranged at the bottom side of the feed end of the fluidized bed 1, and a return port and an exhaust port are arranged at the top. A plurality of atomizing nozzles 12 are arranged on the feed pipe. The feed pipe 11 is a double-layer sleeve, and the gas circuit and liquid circuit inside the nozzle are respectively connected to the double-layer pipeline of the feed pipe 11, and the outer ends of the double-layer pipeline are respectively connected to the pressurized feed pipeline and the high-pressure gas source, and the pressurized feed pipeline is connected to the high-concentration magnesium chloride solution storage tank and the pumping system 2 to transport a high-concentration magnesium chloride solution with a concentration of about 50% into the fluidized bed. The air outlet end of the gas heater 9 is connected to the air inlet at the bottom of the fluidized bed 1, and a gas heating furnace is used. The temperature of the HCl gas outlet end of the gas heating furnace is maintained at about 300°C.

[0021] The tail gas treatment system is connected to the exhaust port of the fluidized bed 1 for purifying and recovering the HCl tail gas. The discharge end of the fluidized bed 1 is connected to a sifter 10, and the small particles of unqualified materials sieved out by the sifter 10 are connected to the return port of the fluidized bed 1 through a return conveying mechanism 14.

[0022] The tail gas treatment system includes a quencher 3, a washing tower 4, a heat exchanger 5, a condenser 6, a preheater, and a circulating fan 8 which are connected in sequence by pipelines. The air inlet end of the quencher 3 is connected to the exhaust port of the fluidized bed 1, and the air outlet end of the circulating fan 8 is connected to the HCl gas heating device 9. The washing tower 4 is provided with a circulating spray device 41, which includes a circulating pump, a circulating pipeline and a plurality of spray heads. The liquid inlet end of the circulating pump is connected to the liquid inlet pipeline through a three-way valve to input washing liquid, and the liquid outlet end of the circulating pump is connected to an external transmission pipeline through a three-way valve, so that the spray washing liquid with increased concentration can be transported to the evaporation concentration device to produce a high-concentration magnesium chloride solution. The circulating pipeline is provided with a circulation pressure by the circulating pump, and the spray head is arranged on the upper side of the inside of the washing tower.

[0023] The heat exchange pipelines of the heat exchanger 5 and the quencher 3 are connected in series in sequence, and the coolant first flows through the heat exchanger 5 and then through the quencher 3. A low-concentration magnesium chloride solution is used as the coolant, and the waste heat of the tail gas is used to preheat the low-concentration magnesium chloride solution while cooling the tail gas. The liquid outlets of the heat exchanger 5 and the condenser 6 are connected to a condensed water collection pipeline, and the condensed water collection pipeline is connected to the hydrochloric acid analysis device 13. The heat exchanger 5 and the condenser 6 remove the water vapor entrained in the tail gas after spray washing by step cooling, and the water vapor is condensed and collected and input into the hydrochloric acid analysis device 13.

[0024] The specific process of the preparation method of the above-mentioned one-step preparation device of anhydrous magnesium chloride disclosed in this utility model patent is as follows:

[0025] The unqualified small particles of anhydrous magnesium chloride are returned as seeds and put into the fluidized bed. High-temperature HCl hot air heated to about 300°C is introduced into the bottom of the fluidized bed to form fluidizing air, which blows up the anhydrous magnesium chloride seeds to form a bed layer of a certain height.

[0026] High-concentration magnesium chloride solution (about 50% concentration) is pumped to the nozzle and driven by the high-pressure airflow to spray upward. The atomized droplets are quickly dehydrated under the action of high-temperature HCl hot air and coated on the surface of anhydrous magnesium chloride seed crystals in the bed until they gradually grow to form anhydrous magnesium chloride particles and are discharged from the discharge end of the fluidized bed.

[0027] After the discharged anhydrous magnesium chloride particles are screened by the screener, qualified products are transported to the next process, and the fine unqualified anhydrous magnesium chloride particles are sent back to the return port of the fluidized bed through the return material conveying mechanism and re-introduced into the fluidized bed as return material.

[0028] The wet tail gas produced by the fluidized bed enters the quencher through the top exhaust port under the action of the circulating fan, and is sent to the scrubber after cooling. The scrubber is sprayed and scrubbed to remove the magnesium chloride dust entrained in the tail gas. The washed tail gas passes through the heat exchanger and condenser in turn to remove the water vapor entrained in the tail gas. After being preheated in the preheater, it is sent to the HCl gas heater, heated to high-temperature HCl hot air and sent to the fluidized bed again. The condensed water discharged from the heat exchanger and condenser will be partially dissolved in the hydrogen chloride, which needs to be collected and transported to the hydrochloric acid analysis system for recycling.

[0029] The above contents are only preferred embodiments of the present invention and cannot be used to limit the scope of implementation of the present invention. That is, all simple equivalent changes and modifications made according to the claims and description of the present invention are still within the scope of the present invention.

Claims

1. A production device for anhydrous magnesium chloride, characterized in that, The production device comprises a fluidized bed, an HCl gas heating device and an exhaust gas treatment system. A feed pipe is arranged at the bottom side of the feed end of the fluidized bed, and a return port is arranged at the top. A plurality of atomizing nozzles are arranged on the inner section of the fluidized bed of the feed pipe. The feed end of the feed pipe is connected to a high-concentration magnesium chloride solution input device. The pipeline of the HCl gas heating device is connected to the air inlet at the bottom side of the fluidized bed. The pipeline of the exhaust gas treatment system is connected to the exhaust port at the top of the fluidized bed.

2. A production device for anhydrous magnesium chloride according to claim 1, characterized in that, The tail gas treatment system comprises a quencher, a washing tower, a dehumidification device and a circulating fan which are sequentially connected by pipelines, the air inlet end of the quencher is connected to the exhaust port of the fluidized bed, and the air outlet end of the circulating fan is connected to the HCl gas heating device.

3. A production device for anhydrous magnesium chloride according to claim 2, characterized in that, The feed pipe is a double-layer sleeve, the gas path and the liquid path inside the atomizing nozzle are respectively connected to the double-layer sleeve of the feed pipe, and the outer ends of the double-layer sleeve are respectively connected to the pressurized feed pipeline and the high-pressure gas source.

4. A production device for anhydrous magnesium chloride according to claim 3, characterized in that, The washing tower is provided with a circulating spray device, which includes a circulating pump, a circulating pipeline and a plurality of spray heads. The liquid inlet end of the circulating pump is connected to the liquid inlet pipeline through a three-way valve, and the liquid outlet end of the circulating pump is connected to the external transmission pipeline through a three-way valve.

5. A production device for anhydrous magnesium chloride according to claim 4, characterized in that, The dehumidification device comprises a heat exchanger and a condenser connected in sequence, the liquid outlet ends of the heat exchanger and the condenser are connected with a condensed water collection pipeline, and the condensed water collection pipeline is connected to a hydrochloric acid analysis device.

6. A production device for anhydrous magnesium chloride according to claim 5, characterized in that, The heat exchange pipelines of the heat exchanger and the quench cooler are connected in series, and the coolant first flows through the heat exchanger and then through the quench cooler.

7. A production device for anhydrous magnesium chloride according to claim 6, characterized in that, The discharge end of the fluidized bed is connected with a sifter, and unqualified materials of the sifter are connected to the return port of the fluidized bed through a return conveying mechanism.

8. A production device for anhydrous magnesium chloride according to claim 7, characterized in that, The tail gas treatment system is further provided with an HCl preheater upstream of the circulating fan.

9. A production device for anhydrous magnesium chloride according to claim 1, characterized in that, The HCl gas heating device is a gas-fired heating furnace, and the temperature of the HCl gas outlet of the gas-fired heating furnace is maintained at 300°C.

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