CN114538396A - Process system and method for producing multi-quality yellow phosphorus and recovering fluorine resources thereof - Google Patents

Abstract

The invention belongs to the technical field of clean production of phosphorus chemical industry, and particularly relates to a process system and a method for producing multi-quality yellow phosphorus and recovering fluorine resources thereof. The invention carries out dust removal treatment on high-temperature furnace gas leaving a yellow phosphorus electric furnace in the yellow phosphorus production process, then carries out the steps of primary or secondary partition wall air cooling or water cooling, primary fluorine-containing saline water direct contact cooling, primary cold water washing and the like, collects yellow phosphorus crude products obtained by condensation in different temperature stages respectively, and then obtains yellow phosphorus with different qualities by conventional refining respectively. The fluorine-containing brine contacts furnace gas and SiF in the circulating process₄The fluosilicate precipitate is produced by reaction, and the fluosilicate resource is recycled, thereby eliminating the generation of phosphorus mud containing hydrated silica gel and process wastewater.

Description

A process system and method for the production of multi-quality yellow phosphorus and its fluorine resource recovery

technical field

The invention belongs to the technical field of clean production of phosphorus chemical industry, and in particular relates to a process system and method for the production of multi-quality yellow phosphorus and the recovery of fluorine resources.

Background technique

At present, industrial yellow phosphorus is produced at home and abroad by using phosphate rock, silica and coke to reduce phosphide in phosphate rock in a high-temperature yellow phosphorus electric furnace. The production process is that the apatite in the phosphate rock is reduced by coke under high temperature conditions to form a mixed gas such as phosphorus steam (P ₂ ) and CO (commonly known as yellow phosphorus furnace gas), which enters the series three-stage direct water washing through the gas guide. The cooling causes the elemental phosphorus vapor in the furnace gas to condense to become liquid yellow phosphorus (P ₄ ), which is mixed together to form crude industrial yellow phosphorus, and is conventionally refined to obtain industrial yellow phosphorus. At the same time, under the high temperature reducing atmosphere in the electric furnace, the arsenate in the phosphate rock is also reduced to elemental arsenic, and the fluoride such as fluorapatite in the phosphate rock reacts with silica to produce SiF gas _. . Under normal circumstances, the fluorine content in phosphate rock is in the range of 1-4%, and the gas phase escape rate of fluorine in the process of producing yellow phosphorus by electric furnace method is affected by the _acidity of the charge. , the gas phase escape rate of fluorine is relatively high. When the acidity index is conventional, the escape rate of fluorine is about 10%-90%, and the remaining part of fluorine is retained in the phosphorus slag. Obviously, the yellow phosphorus furnace gas entering the outlet pipe of the electric furnace contains not only phosphorus vapor and carbon monoxide, but also impurities such as silicon tetrafluoride gas, elemental arsenic and dust. The refining process of crude yellow phosphorus and the quality of yellow phosphorus have adverse effects. Due to the mixing of silica colloid and ash and yellow phosphorus produced by the hydrolysis of SiF ₄ in the furnace gas during the washing process, the existence of hydrated silica colloid has an adverse effect on yellow phosphorus. It is difficult to separate from ash, so the existing traditional yellow phosphorus process inevitably produces a large amount of phosphorus sludge containing high phosphorus content, which directly affects the yield of yellow phosphorus products, not only causes waste of resources, but also produces serious water pollution and pollution. Arsenic contamination of soils, etc.

The invention patent (CN 104276549 B) makes full use of the large difference between the condensation temperature and desublimation temperature of yellow phosphorus and arsenic vapor, and realizes the separation of arsenic and phosphorus based on this. Part of the dust in the furnace gas and the solid elemental arsenic precipitated by desublimation (or adsorbed on the dust) are then graded (sections) to directly wash and cool the furnace gas, and graded (sections) to collect the condensed and precipitated yellow phosphorus, and respectively. Different (arsenic-containing) quality yellow phosphorus products are obtained. _In addition, this invention also proposes to utilize SiF4 hydrolysis reaction temperature conditions below 120 ℃, through step-by-step dedusting and cooling of furnace gas, to partially avoid dust and _SiF4 hydrolysis generated silica colloidal particles and yellow phosphorus mixing, obviously, in When the furnace gas is in direct contact with water, it is difficult to completely eliminate the influence of the silica hydrocolloid produced by the hydrolysis of SiF ₄ in the furnace gas on the separation of yellow phosphorus and dust. It is difficult to control the industrial process, and a small amount of phosphorus sludge will also be produced. And the effect on the quality of yellow phosphorus. Moreover, the process method described in this patent cannot solve the problem of recovery of fluorine and silicon resources in the production process.

At present, the production capacity of existing domestic yellow phosphorus enterprises is relatively large. Although the production process of yellow phosphorus is simple, the content of impurities in the yellow phosphorus produced is relatively high, especially arsenic and silicon. The requirements for phosphorus, and a large amount of phosphorus sludge and process wastewater are generated, belong to the "two high" industries, and are in urgent need of industrial technology upgrading. At home and abroad, there are few studies on the preparation of yellow phosphorus of different quality based on the production process control of yellow phosphorus, and the use of different cooling methods in the production process of yellow phosphorus and the simple control of the transfer of impurities and fluorine and silicon to obtain yellow phosphorus of different quality There is no relevant report on the technology of recovering the fluorine resources therein. With the increasingly strict requirements for cleaner production, energy conservation and emission reduction in the chemical industry at home and abroad, coupled with the rise of the fluorine chemical industry in recent years, the domestic and international markets have strong demand for fluorine resources, and the phosphorus in major phosphate mining areas such as Yunnan, Guizhou, and Hubei has become more and more stringent. The fluorine content of ore is relatively high. Obviously, the technology of removing impurities from yellow phosphorus based on process control and recovering fluorine resources has gradually become an urgent technology for yellow phosphorus production enterprises.

SUMMARY OF THE INVENTION

The purpose of the present invention is to aim at the high impurity content in the yellow phosphorus produced by the current industrial process, and it is unavoidable to generate a large amount of production waste water and the phosphorus sludge containing hydrated silica gel and a large amount of fluorosilicon resources that cannot be effectively recovered, etc., to provide a beneficial It is a process method for controlling the production process of yellow phosphorus and facilitating the recovery of fluorine and silicon resources therein. The method is that the high-temperature furnace gas leaving the yellow phosphorus electric furnace (containing phosphorus steam, arsenic steam, SiF ₄ , dust and other gases) in the production process of yellow phosphorus is subjected to dust removal treatment, and then subjected to one-stage or two-stage partition wall air cooling. Or the steps of water cooling on the partition wall, direct contact cooling with primary fluorine-containing brine, and primary cold water washing, etc., and collect the yellow phosphorus crude products obtained by condensation at different temperature stages, and then obtain yellow phosphorus of different quality through conventional refining. The fluorine-containing brine reacts with SiF ₄ in the furnace gas during the cooling cycle to produce fluorosilicate precipitation, recover fluorine and silicon resources, and eliminate the production of hydrated silica-containing phosphorus sludge and process wastewater.

In order to achieve the above purpose, the technical principle adopted in the present invention is: the principle of realizing the separation of arsenic and yellow phosphorus by making full use of the temperature difference existing in the saturated steam of yellow phosphorus and arsenic, after removing most of the arsenic-containing dust impurities by a dust collector. The yellow phosphorus furnace gas above 200 ℃ adopts the unit operation of one-stage or two-stage partition wall air-cooling or one-stage partition water-cooling heat exchange, so that the furnace gas temperature is reduced to 95-120 ℃. From the data related to the relationship between steam partial pressure and temperature, it can be calculated that about 90% of the phosphorus vapor is condensed and separated out and collected in the hot water tank in stages. After conventional refining, it can be a low-arsenic industrial yellow phosphorus product. Obviously, the cooling of the partition wall makes the _SiF in the furnace gas not in direct contact with the spray water, so as to avoid the influence of its hydrolysis on the refining and quality of the yellow phosphorus (the presence of the hydrated silica colloid produced by the hydrolysis causes the separation of the yellow phosphorus and the ash). difficult, so the existing traditional yellow phosphorus process inevitably produces a large amount of phosphorus sludge, which affects the yield of the yellow phosphorus product). In addition, the heated air in the air-cooling process is used to dry the ore raw materials entering the furnace, which is beneficial to increase the discharge temperature of the yellow phosphorus furnace gas and is beneficial to the previous dust removal operation. The furnace gas after cooling and heat exchange is passed through the fluorine brine washing tower, and the fluorine-containing brine containing a certain concentration of KF or NaF, NH ₄ F and HF and other fluorides is used as the cooling absorption liquid. These fluoride solutions can absorb the fluoride in the furnace gas. SiF ₄ can react with it to produce fluorosilicate or fluorosilicic acid, inhibit the hydrolysis of SiF ₄ , and eliminate its interference on the refining operation of yellow phosphorus. At the same time, it provides a way for the recovery of fluorine and silicon resources.

Taking the potassium fluoride aqueous solution as the cooling absorption liquid as an example, the specific reaction is as follows:

SiF ₄ +2KF=K ₂ SiF ₆ ↓ (1)

K ₂ SiF ₆ ↓+H ₂ O=4HF+H ₂ SiO ₃ +2KF (boiling water) (2)

K ₂ SiF ₆ +2K ₂ CO ₃ =6KF+SiO ₂ ↓+2CO ₂ ↑ (3)

2KF+Na ₂ CO ₃ =NaF↓+K ₂ CO ₃ (4)

_In order to prevent the hydrated silica colloid generated by the hydrolysis of SiF in the furnace gas from interfering with the separation of the ash and yellow phosphorus washed from the furnace gas, using the high solubility of KF in water, a higher concentration of KF aqueous solution can be prepared as The cooling absorption liquid absorbs SiF ₄ in the furnace gas and reacts to form K ₂ SiF ₆ precipitation, such as reaction (1), which can inhibit the influence of SiF ₄ hydrolysis on the refining and separation of yellow phosphorus. In addition, the condensed liquid yellow phosphorus is discharged together with the cooling absorption liquid, and the solid-liquid separation is carried out to obtain solid precipitated potassium fluorosilicate (or contains a small amount of ash), and the upper layer of the liquid is a dilute potassium fluoride solution, which is recycled. The lower layer is the crude yellow phosphorus product, which can be a higher-purity yellow phosphorus product after conventional refining treatment.

Regeneration cycle of cooling absorption liquid and recovery of fluorine and silicon resources. The solid potassium fluorosilicate separated by solid-liquid separation is easily hydrolyzed in water at about 100°C, such as reaction (2), and silicic acid is only soluble in hydrofluoric acid solution, and this feature can also be used to remove solid ash. Therefore, adding a certain amount of potassium carbonate or potassium bicarbonate and potassium hydroxide to the recovered potassium fluorosilicate hot solution, and reacting for a period of time at 95 to 110° C., the reaction is as in (3). Silica is obtained by filtration, washed and refined to produce white carbon black; the liquid is KF saturated solution, the potassium fluoride product is obtained by cooling and crystallization, part of the crystallization mother liquor is recycled and concentrated, and part is used as a coolant-fluorine-containing brine supplement.

If the economical problem of using potassium salt is considered, the characteristic of sodium fluoride being slightly soluble in water can be fully utilized, and sodium carbonate or sodium bicarbonate and sodium hydroxide are added to the above-mentioned KF saturated solution, a displacement reaction (4) occurs, and the solution is cooled to The sodium fluoride product is obtained by filtration at room temperature; the filtrate is potassium carbonate solution, which can be recycled as a raw material for processing potassium fluorosilicate.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is as follows: a process method for yellow phosphorus production and fluorine resource recovery thereof, when the temperature of the furnace gas outlet leaving the yellow phosphorus electric furnace in the yellow phosphorus production process is 220～300 ℃, First, the yellow phosphorus electric furnace gas is removed by a dust collector to remove about 90% of the dust impurities and arsenic dust from desublimation, and then enters the first or two-stage partition wall air cooling or partition wall water cooling, and the first-level fluorine-containing brine is directly contacted for cooling and washing. and first-level cold water washing and other steps, and collect the yellow phosphorus crude products obtained by condensation at different temperature stages, and then simply refine to obtain yellow phosphorus of different quality. The cooling fluorine brine is circulated and reacted with SiF ₄ in the furnace gas, and the fluorine and silicon resources in it are recovered. The details of the plan are as follows.

A process system for multi-quality yellow phosphorus production and its fluorine resource recovery, comprising:

a dust collector, which has a yellow phosphorus furnace gas inlet, a yellow phosphorus furnace gas outlet and an ash outlet arranged at the bottom, and the ash outlet communicates with the semi-sealed ash bin;

The partition cooling device has a high temperature material inlet arranged at the top, a cooling material outlet arranged at the lower part, a condensate outlet arranged at the bottom, a cooling medium inlet and a cooling medium outlet, and the yellow phosphorus furnace gas outlet is connected to the The high temperature material inlet, the cooling medium inlet is connected to the cooling medium conveying equipment and the cooling medium inlet pipe in turn, the condensate discharge port is connected to the water-sealed yellow phosphorus collection tank, and the water-sealed yellow phosphorus collection tank has an industrial yellow phosphorus collection port , the cooling medium outlet is also connected to the cooling medium conveying equipment, the cooling medium is normal temperature air or water, correspondingly, the partition cooling device is a partition air cooling device or a partition water cooling device, and the cooling medium conveying equipment is a blower or water pump;

The fluorine-containing salt water spray tower has a first air inlet, a first air outlet, a first shower head and a potassium fluoride solution collection port arranged at the bottom, and the cooling material outlet is connected to the first air inlet , the potassium fluoride solution collection port is connected to the fluorine-containing brine collection and precipitation tank, and the fluorine-containing brine collection and precipitation tank has a mixed solution collection port for yellow phosphorus, potassium fluorosilicate precipitation and potassium fluoride, and the fluorine-containing brine collects The sedimentation tank is also communicated with the first shower head through a fluorine-containing brine circulating pump;

And a cold water spray tower, which has a second air inlet, a yellow phosphorus tail gas outlet, a bottom discharge port and a second spray head, the first air outlet is connected to the second air inlet, and the bottom is discharged. The port is connected to a cold water collection and circulation tank, the cold water collection and circulation tank has a high-purity yellow phosphorus collection port, and is also connected to the second shower head through a cold water circulation pump.

Further, the system also includes:

Separation device, its feed port is connected to the conveying equipment pipeline of the mixed liquid collection port of the yellow phosphorus, potassium fluorosilicate precipitation and potassium fluoride, and its liquid outlet is connected to a gravity settling liquid separator, and the gravity settling liquid separator With low impurity yellow phosphorus collection port;

Reactor, one of its feed ports is respectively connected with the slag outlet of the separation device and the supernatant liquid outlet of the described gravity settling liquid separator, and its other feed port is the potassium carbonate solution feed port;

The filter, its feed port is communicated with the discharge port of the reactor, and its discharge port is communicated with the potassium fluoride saturated liquid collection port through a valve, and is also communicated with an evaporation concentration cooling crystallizer and a centrifuge in turn. The discharge port is communicated with the potassium fluoride solution reuse port, and is also communicated with the evaporation, concentration and cooling crystallizer through a valve, the filter has a by-product silica collection port, and the centrifuge has a by-product potassium fluoride crystal collection port. mouth.

The cooling medium is normal temperature air or water, and correspondingly, the partition cooling device is a partition air cooling device or a partition water cooling device. The cooling medium conveying equipment is a blower or a water pump. The separation device is a plate filter or a three-phase centrifugal separator.

Further, the system also includes:

Replacement reaction kettle, one of its feed ports is connected to the potassium fluoride saturated liquid collection port, the other of its feed ports is a sodium carbonate feed port, and its discharge port is communicated with a heat exchanger and a sodium fluoride filter in turn, so the The sodium fluoride filter has a potassium carbonate solution collection port and a by-product sodium fluoride crystal collection port.

The present invention also provides a process method for the production of multi-quality yellow phosphorus and its fluorine resource recovery, which can be produced by the above-mentioned system provided by the present invention, and specifically includes the following steps:

1) The yellow phosphorus electric furnace gas flowing out from the yellow phosphorus furnace gas inlet is above 230°C, and the dust is dedusted in the dust collector to separate the dust, and obtain a temperature above 200°C to remove the dust containing elemental arsenic Removal of impurities in the yellow phosphorus furnace gas; when the temperature of the yellow phosphorus furnace gas introduced from the yellow phosphorus furnace gas inlet is in the range of 140 to 180 °C, and part of the gaseous phosphorus is condensed and precipitated, and the dust removal operation cannot be performed, the yellow phosphorus The furnace gas is directly passed into the fluorine-containing salt water spray tower for step 3) and subsequent steps.

2) Passing the yellow phosphorus-removing furnace gas obtained in step 1) for removing dust impurities containing arsenic simple substance obtained in step 1) into the partition heat exchange device for cooling, and separating to obtain a condensed effluent and a temperature of 95 ℃. -120℃ containing _SiF4 furnace gas, collect and refine the condensed effluent to obtain low arsenic industrial yellow phosphorus;

₃ ) The SiF obtained in step 2) is passed into the fluorine-containing salt water spray tower for spraying, and the obtained condensed and separated liquid yellow phosphorus, potassium fluorosilicate precipitate and potassium fluoride The mixed liquid flows into the fluorine-containing brine collection and precipitation tank, and the mixture of liquid and precipitated crystal particles in the tank can be recycled to the first spray head for spraying through the fluorine-containing brine circulation pump, and at the same time, the removal of SiF ₄ The furnace gas, wherein, the spray liquid is 10-45% potassium fluoride solution, its temperature is 30-50 ℃, and the temperature of the furnace gas for removing SiF ₄ is 50-60 ℃;

4) The furnace gas obtained in step 3) for removing SiF ₄ is passed into the cold water spray tower for washing and cooling, and a small amount of gaseous yellow phosphorus remaining in the furnace gas is condensed into solid yellow phosphorus particles and dispersed in the In the cold water, the yellow phosphorus tail gas is discharged at the same time, and the cold water with dispersed yellow phosphorus particles is collected by precipitation to collect solid yellow phosphorus, and then it is heated and refined to obtain high-purity yellow phosphorus, and the supernatant liquid is precipitated—the cold water is then circulated through the cold water circulation pump. It is used for spraying to the second spray head, wherein the temperature of the yellow phosphorus tail gas is 10-35°C.

Further, the method also includes step 5):

5a) The mixed solution of liquid yellow phosphorus, potassium fluorosilicate precipitation, ash content and potassium fluoride obtained in step 3) is passed into the separation device and filtered, and the filtrate is kept at rest through the gravity settling separator again. Layering to obtain low-impurity yellow phosphorus, which can be refined to obtain high-purity yellow phosphorus; the yellow phosphorus furnace gas whose temperature is in the range of 140 to 180° C. in step 1) is obtained without dedusting and step 2) directly performing step 3) operation. The crude yellow phosphorus product is refined to obtain industrial yellow phosphorus;

5b) Put the potassium fluorosilicate crystal containing part of the ash separated by the separation device into the reaction kettle, and add the supernatant obtained by the gravity settling liquid separator, and heat it to 100 ° C to make it hydrolyzed into The solution is filtered to remove the ash, and then the replacement mother liquor (mainly containing potassium carbonate or potassium bicarbonate) of potassium carbonate or the subsequent obtained sodium fluoride is added to make high-concentration materials, and the reaction is carried out at 95 to 110 ° C. Silica is obtained by filtering with a filter, which can be washed and refined to produce white carbon black, and a nearly saturated potassium fluoride solution is obtained;

5c) the obtained nearly saturated potassium fluoride solution is cooled and crystallized to separate out potassium fluoride through the described evaporative concentration cooling crystallizer, the potassium fluoride crystal product is obtained through the dehydration of the centrifuge, and the remainder is that the mother liquor is rich in after crystallization. Potassium fluoride, a part of which is used as a supplement for the cooling absorption liquid potassium fluoride solution, and the other part is sent to the concentrated cooling crystallizer for use.

Further, the method also includes step 6): the hot near-saturated potassium fluoride solution obtained in the step 5b) is sent into the replacement reaction kettle, sodium carbonate is added to generate a replacement reaction, and then the heat exchange is carried out. The device is cooled to room temperature for crystallization, filtered through the sodium fluoride filter to obtain the sodium fluoride crystal product, and the filtrate can be used as the replacement mother liquor of the sodium fluoride (mainly containing potassium carbonate or potassium bicarbonate).

The specific principle of step 1) is: first pass the yellow phosphorus electric furnace gas through a dust collector (multi-tube cyclone dust collector or electrostatic precipitator, etc.) to remove about 90% of the dust impurities containing arsenic element. According to the partial pressure calculation, the dew point of phosphorus vapor precipitation is about 180 ℃. When the temperature of the furnace gas after purification by the dust collector is above 200 ℃, the collected dust does not contain elemental phosphorus, but contains elemental arsenic, which should be disposed of in a standardized manner.

The specific principle of step 2) is: the yellow phosphorus furnace gas after removing most of the arsenic-containing dust impurities by the dust collector is about 200 ℃ or more, and the cooling unit is operated by using a one-stage or two-stage partition wall air-cooled or water-cooled heat exchanger, so that the The furnace gas temperature drops to 95-120°C, and most of the phosphorus vapor is condensed and precipitated and collected in the hot water tank at the bottom of the air-cooled heat exchanger, and then conventionally refined into low-arsenic industrial yellow phosphorus. If two-stage air cooling is adopted, the yellow phosphorus condensate will be collected in the hot water tank and then be conventionally refined into general industrial yellow phosphorus and low impurity yellow phosphorus. In addition, in order to reduce the resistance loss of the furnace gas system and prevent blockage in the tube, the heat exchanger adopts a single-pass vertical large tube heat exchanger to control the height-diameter ratio; the cooling medium is air or water to go outside the tube (shell side), The blower or water pump is forced to convey and operate in countercurrent. The operation unit is also equipped with an outlet hot air or hot water return pipe with adjustable flow to increase the temperature of the mixed inlet and prevent the air or cold water from being supercooled in winter. Thermal effects even clog. The outlet air heated on the shell side of the heat exchanger is used to dry the ore raw materials entering the furnace, which is beneficial to increase the discharge temperature of the yellow phosphorus furnace gas. It is convenient for the dust collector to operate without the precipitation of elemental phosphorus.

The specific principle of step 3) is: the temperature of the furnace gas leaving the lower part of the air-cooled heat exchanger is about 110 ° C, entering the fluorine-containing salt water spray tower from the bottom, and directly contacting the fluorine-containing salt water sprayed from the top of the tower to cool down, containing The temperature of the fluoride brine is about 45°C. Control the spray amount of fluorine-containing brine so that the temperature of the furnace gas leaving the spray tower is about 50-55 °C, and the first product of liquid yellow phosphorus is condensed and precipitated from the bottom of the spray tower, together with the fluoride brine and the reaction precipitate fluorosilicate flows into the fluorine-containing salt. The brine collection and sedimentation tank, the mixture of liquid and crystal particles in the tank is recycled and sprayed for a period of time, the fluorosilicate crystal particles in the tank gradually grow up and accumulate with the condensed liquid yellow phosphorus to a certain amount and then discharge, and the filtration is relatively good. Large particles of solid fluorosilicate (potassium or sodium), the filtrate is kept at rest for stratification, and the bottom is crude yellow phosphorus, which can be obtained by conventional refining to obtain higher purity yellow phosphorus. The upper liquid is a fluorine-containing salt solution. A certain amount of fluoride salt is regularly added to the fluorine-containing brine circulation system to maintain the fluoride-containing salt concentration in the brine circulation spray system. In this step, the main reaction is the above-mentioned reaction (1).

The specific principle of step 4) is: the proportion of phosphorus vapor partial pressure in the furnace gas leaving the fluorine brine spray tower is very low, but the impurity content is also extremely low, and the furnace gas at about 50 to 60 ° C enters the cold water spray tower from the bottom. Clean water is used for washing and cooling for spraying, and the amount of clean water spraying is controlled so that the temperature of the exhaust gas of the furnace is about 20 °C; the yellow phosphorus obtained by condensation at this stage is very little and is in a solid and dispersed state, and the yellow phosphorus flows into the yellow phosphorus from the bottom of the tower with water. In the collection tank, solid yellow phosphorus is deposited at the bottom of the collection tank, discharged regularly, heated to a liquid state for refining, and extremely high-purity yellow phosphorus can be obtained. Finally, the remaining exhaust gas is sent to the gas cabinet through the centrifugal fan.

The specific principle of step 5) is: put the potassium fluorosilicate separated by filtration into the reaction kettle, add water or 3) step upper layer liquid (fluorinated brine) and heat it at about 100 ° C to make it hydrolyzed into a solution, and filter to remove the ash content. , then add a certain amount of potassium carbonate or potassium bicarbonate, potassium hydroxide (or the replacement mother liquor for the subsequent preparation of sodium fluoride) to make a higher concentration material, react for a period of time under 95 ~ 110 ℃ conditions, filter to obtain silica , washing and refining to produce white carbon black; the liquid is KF (close to saturation) solution, and the potassium fluoride product is precipitated by cooling and crystallization after cooling or concentrating, and the rest is the mother liquor after crystallization, which is still rich in potassium fluoride, and a part of it is used as the cooling absorption liquid. The supplementary solution can be recycled to the front end of the reaction for application. In this step, the main reactions are the above-mentioned reaction (2) and reaction (3).

The concrete principle of step 6) is: if sodium fluoride is used as the final product of the recovery process, the water-soluble potassium fluoride can be fully utilized, and the characteristic that sodium fluoride is slightly soluble in water, the hot KF saturated solution obtained by the above-mentioned filtration Sodium carbonate or sodium bicarbonate and sodium hydroxide are added to it, a displacement reaction occurs, and the sodium fluoride product is obtained by filtration at room temperature; It can be recycled as a reaction raw material for the treatment of potassium fluorosilicate. In this step, the main reaction is the above-mentioned reaction (4).

According to the above scheme, the conventional refining treatment of the yellow phosphorus is to go through separation processes such as water rinsing, gravity sedimentation or centrifugal sedimentation.

According to the above scheme, the fluorine-containing brine is a single-component aqueous solution or a mixed solution of two or more components containing a certain concentration of KF or NaF, NH ₄ F, HF and other fluorides, wherein the concentration of the KF aqueous solution is 3% ~45%, NaF aqueous solution concentration is 0% ~ 5%, NH ₄ F aqueous solution concentration is 0% ~ 15%, HF aqueous solution concentration is 0% ~ 15%.

According to the scheme, the mother liquor after the described crystallization is the filtrate-potassium fluoride solution obtained by the reaction of potassium fluorosilicate and potassium carbonate, and the remaining liquid of the potassium fluoride crystal is separated out through cooling or concentrating cooling, wherein still rich in a certain amount of concentration of potassium fluoride.

According to above-mentioned scheme, described replacement mother liquor is the filtrate that potassium fluoride and sodium carbonate solution take place replacement reaction, the filtrate produced after filtration at reduced temperature, wherein the main component is potassium carbonate, and contains a small amount of slightly soluble sodium fluoride and potassium fluoride There will be no negative impact on subsequent cycles.

Compared with the prior art, the beneficial effects of the present invention are:

1) The present invention directly adopts steps such as dedusting, one-level or two-level air cooling, one-level fluorine-containing salt water washing and one-level cold water washing and cooling steps for the furnace gas leaving the yellow phosphorus electric furnace in the yellow phosphorus production process, and collects different temperatures respectively. The crude liquid yellow phosphorus obtained by staged condensation is then conventionally refined to obtain different quality yellow phosphorus products, which avoids the influence of impurities such as arsenic and silicon in the furnace gas on the quality and yield of yellow phosphorus, and can meet the requirements of downstream industries. Different requirements for the quality of elemental phosphorus. At the same time, it also helps to solve the problems of arsenic pollution and water pollution that plague phosphorus chemical industry.

2) the present invention proposes to first adopt partition wall heat exchange to cool down and condense most of the yellow phosphorus steam to the yellow phosphorus furnace gas, which avoids the subsequent separation of yellow phosphorus and ash by the hydrated silica colloid produced by the hydrolysis of SiF due to the existing use of water washing and cooling _. The subsequent furnace gas is directly sprayed and cooled with fluorine-containing brine, which realizes the absorption reaction of SiF ₄ in the furnace gas, which not only eliminates the production of phosphorus sludge, but also improves the yield of yellow phosphorus products, and can recover fluorine in the phosphate rock. , silicon resources, and provide technical support for the transformation and upgrading of the phosphorus chemical industry.

3) The present invention is suitable for process design and technological upgrading and transformation of a single yellow phosphorus electric furnace with a production capacity of 5,000-30,000 tons/year, and the involved production process and operation are simple and meet actual production requirements.

Description of drawings

FIG. 1 is a schematic structural diagram of a system part used in the process method for the production of multi-quality yellow phosphorus and its fluorine resource recovery in Example 1 of the present invention.

FIG. 2 is a schematic structural diagram of the system part used in the fluorine resource recovery part involved in Example 1 of the present invention.

Fig. 3 is the structural representation of the system part adopted in the production of sodium fluoride involved in the embodiment of the present invention 2 and the reuse of its potassium salt.

In accompanying drawings 1, 2, and 3:

1. Dust collector, 2. Air-cooled heat exchanger, 3. Fluorinated brine spray tower, 4. Cold water spray tower, 5. Semi-sealed ash bin, 6. Water-sealed yellow phosphorus collection tank, 7. Fluorinated brine Collection and sedimentation tank, 8. Cold water collection and circulation tank, 9. Cooling medium conveying equipment, 10. Fluorinated brine circulation pump, 11. Cold water circulation pump, 12. Separation device, 13. Gravity sedimentation separator, 14. Reactor, 15. Filter, 16. Evaporative concentration cooling crystallizer, 17. Centrifuge, 18. Replacement reaction kettle, 19. Heat exchanger, 20. Sodium fluoride filter;

101, yellow phosphorus furnace gas inlet, 102, yellow phosphorus tail gas outlet, 103, cooling medium inlet pipe, 104, cooling medium outlet, 105, potassium carbonate solution feeding port, 106, silica collection port, 107, by-product fluorine Potassium chloride crystal collection port, 108, sodium carbonate feed port, 109, by-product sodium fluoride crystal collection port;

201, the potassium fluoride solution reuse port, 202, the mixed solution collection port of yellow phosphorus, potassium fluorosilicate precipitation and potassium fluoride, 203, the potassium fluoride saturated solution collection port;

301, industrial yellow phosphorus collection port, 302, low impurity yellow phosphorus collection port, 303, high purity yellow phosphorus collection port.

Detailed ways

The principles and features of the present invention are described below, and the examples are only used to explain the present invention, but not to limit the scope of the present invention.

Example 1

A process system and method for the production of multi-quality yellow phosphorus and its fluorine resource recovery, aiming at a production device (annual operating hours of 7200h) of a yellow phosphorus electric furnace (15000KVA) with an output of 7500 tons/year, wherein the phosphate rock entering the furnace contains pentoxide Diphosphorus is 30.5%, fluorine content is ² %, the gas phase escape rate of fluorine is 20%, the ratio of raw and auxiliary materials and other operating conditions are the same as those in conventional operation. ℃, using the process technology shown in Figure 1 and Figure 2 to control the subsequent production process of yellow phosphorus, the specific steps include:

1) The yellow phosphorus furnace gas leaving the yellow phosphorus electric furnace is removed by the multi-cyclone type dust collector 1 to remove solid dust (including the dust that adsorbs arsenic), in order to ensure that the dust collected in the dust hopper 1 has a certain fluidity, After the dust collector 1 is heat-insulated or the yellow phosphorus tail gas is burned to supplement heat energy, the temperature of the purified furnace gas leaving the dust collector 1 is above 220°C. The dust enters into the semi-closed ash bin 5 .

2) The yellow phosphorus furnace gas after removing most of the arsenic-containing dust impurities by the dust collector 1 is then used for the cooling unit operation by the air-cooled heat exchanger 2 of the first-stage partition type. The air-cooled heat exchanger 2 is a single-pass vertical type Large tube heat exchanger, the cooling medium is the air from the cooling medium inlet pipe 103 to go outside the pipe (shell side), the cooling medium conveying equipment 9 is a blower, forced air supply, countercurrent operation, so that the furnace gas temperature is reduced to 100~ 110°C. Most of the phosphorus vapor in the furnace gas is condensed and precipitated and collected in the water-sealed yellow phosphorus collection tank 6 at the bottom of the air-cooled heat exchanger. After being collected from the industrial yellow phosphorus collection port 301, it is conventionally refined into low-arsenic industrial yellow phosphorus. The air cooling system is equipped with an outlet hot air return pipe with adjustable flow to increase the mixed inlet air temperature and prevent the solidification of the yellow phosphorus in the local pipe caused by the supercooling of the air, which will affect the heat transfer effect or even block. In addition, the temperature of the heated outlet air discharged from the cooling medium outlet 104 can reach more than 110° C., which is used for drying the raw materials entering the furnace, so as to increase the discharge temperature of the yellow phosphorus furnace gas.

3) leave the furnace gas at the bottom of the air-cooled heat exchanger 2 and enter the fluorine-containing salt water spray tower 3 from the bottom of the spray tower, and directly contact and cool with the 14% potassium fluoride solution sprayed from the top of the tower, and the temperature of the potassium fluoride solution is About 45 ℃ or so. Control the spray amount of fluorine-containing brine so that the temperature of the furnace gas leaving the spray tower is about 55 ℃, and the liquid yellow phosphorus, fluorosilicate precipitation and the remaining potassium fluoride solution are condensed and precipitated into the fluorine-containing brine collection and sedimentation tank 7. The mixture of the inner liquid and the precipitated crystal particles is then circulated and sprayed by the fluorine-containing brine circulating pump 10 for use. After the potassium fluorosilicate crystal particles gradually grow up and accumulate to a certain amount with the condensed liquid yellow phosphorus, it is discharged, and the larger particles of solid potassium fluorosilicate are filtered by the separation device 12 of the plate filter, and the filtrate is then gravity filtered. The sedimentation separator 13 is kept at rest for stratification, and the bottom is the yellow phosphorus crude product, which is collected from the low-impurity yellow phosphorus collection port 302, and can obtain higher-purity yellow phosphorus through conventional refining. The upper liquid is a solution containing residual potassium fluoride, which is used as a hydrolysis solution of potassium fluorosilicate.

4) The furnace gas leaving the fluorine brine spray tower 3 enters the cold water spray tower 4 from the bottom to wash and cool down, use clean water for spraying, and control the amount of clean water sprayed, so that the temperature of the furnace gas tail gas is about 20 ° C; condensation obtains The yellow phosphorus is very little and is in a solid dispersed state, and flows into the cold water collection and circulation tank 8 with the water from the bottom of the tower. Refined to obtain extremely high-purity yellow phosphorus. Finally, the remaining tail gas is sent to the tail gas tank from the yellow phosphorus tail gas outlet 102 through the exhaust fan.

5) The potassium fluorosilicate crystal containing a small amount of ash separated by the plate filter is put into the reactor 14, and the supernatant (residual potassium fluoride solution) of the gravitational force sedimentation separator 13 is heated and hydrolyzed at 100° C. , add a certain amount of potassium carbonate (or the replacement mother liquor for the subsequent preparation of sodium fluoride) to make a higher concentration material, react for a period of time under the conditions of 95 ~ 110 ° C, after being filtered by the filter 15, in the silica collection port 106 Silica is obtained, washed and refined to produce white carbon black; the liquid is KF (close to saturation) solution, which is cooled and crystallized by evaporation, concentration and cooling crystallizer 16 to separate out potassium fluoride, dehydrated by centrifuge 17, and collected at the by-product potassium fluoride crystal collection port. 107 Collect potassium fluoride crystal product. The remainder is that the mother liquor after crystallization is rich in potassium fluoride, and a part can be obtained from the potassium fluoride solution reuse port as a supplementary liquid of the cooling absorption liquid potassium fluoride solution, and the other part is sent to the evaporative concentration cooling crystallizer 16 of the cooling for mechanical use. Among them, the cooling medium can also be air, the corresponding partition wall cooling device adopts the partition wall air cooling device, and the cooling medium conveying device is a blower.

The main product technical indicators of this method are:

Yellow phosphorus product technical indicators: the yield of each quality yellow phosphorus product accounts for 99% of the total phosphorus in the furnace gas leaving the yellow phosphorus electric furnace. Among them, the yield of general industrial yellow phosphorus is 90% (accounting for the mass fraction of the total phosphorus product obtained), the arsenic content is 64 mg/kg, and does not contain silicon impurities; the yield of higher-purity yellow phosphorus is 9% (accounting for the total phosphorus obtained). product mass fraction), the arsenic content is 8.3mg/kg; the yield of high-purity yellow phosphorus is 1.0% (accounting for the obtained total phosphorus product mass fraction), the arsenic content is below 1.4mg/kg, and does not contain silicon impurities.

Fluorine resource recovery index: The recovery rate of fluorine resources accounts for 90% of the total gas phase escape from the yellow phosphorus electric furnace; the by-product potassium fluoride product per ton of yellow phosphorus produced is about 99.1 kg.

Example 2

A process system and method for multi-quality yellow phosphorus production and its fluorine resource recovery, aiming at a yellow phosphorus electric furnace production device with an output of 10,000 tons/year (annual operating hours of 7200h), wherein the phosphate rock entering the furnace contains phosphorus pentoxide (P ₂ O ₅ ) was 29.8%, the fluorine content was 3%, the gas phase escape rate of fluorine was 15%, and the ratio of raw and auxiliary materials and other operating conditions were the same as those of conventional operations. The yellow phosphorus electric furnace has a gas volume of about 14000 m ³ /h and a temperature of about 260 ° C. The process technology shown in Figure 1, Figure 2 and Figure 3 is used to control the subsequent yellow phosphorus production process and fluorine resource recovery. The specific steps include:

1) The dehydration leaving the yellow phosphorus electric furnace removes solid dust through electrostatic precipitator 1, and controls the temperature of the purified furnace gas leaving the precipitator 1 to be above 220°C. The dust enters into the semi-closed ash bin 5 .

2) The first-stage partition-type water cooling heat exchanger 2 is used for the cooling unit operation for the yellow phosphorus furnace gas. The water cooling heat exchanger 2 is a single-pass vertical large tube heat exchanger, and the cooling medium is transported The equipment 9 is a water pump, which feeds the normal temperature water into the shell side of the heat exchanger, operates in countercurrent, and controls the amount of water to reduce the temperature of the furnace gas to 110-120°C. The phosphorus vapor is condensed and precipitated in the tube side and collected in the hot water tank 6 at the bottom of the water-cooled heat exchanger 2, and then conventionally refined into low-arsenic industrial yellow phosphorus 301. The heated outlet hot water can be used for other purposes or cooled and circulated through the cooling water system.

3) leave the furnace gas at the bottom of the water-cooled heat exchanger 2 and enter the fluorine-containing salt water spray tower 3 from the bottom of the spray tower, and directly contact and cool with the 12% potassium fluoride and 1% sodium fluoride mixed solution sprayed from the top of the tower, The spray amount of potassium fluoride solution is controlled so that the temperature of the furnace gas leaving the spray tower is about 50°C, and the liquid yellow phosphorus, fluorosilicate precipitation and the remaining potassium fluoride solution are condensed and separated into the fluorine-containing brine collection and sedimentation tank 7 together, The mixture of liquid and precipitated crystal particles in the tank is then circulated and sprayed by the fluorine-containing brine circulating pump 10 for use. After the fluorosilicate crystal particles gradually grow up and accumulate to a certain amount with the condensed liquid yellow phosphorus, they are discharged, and the larger particles of solid potassium fluorosilicate (containing a small amount of fluorosilicate) are filtered by the separation device 12 of the plate filter. Sodium), the filtrate is then kept for stratification by the gravity sedimentation separator 13, and the bottom is the yellow phosphorus crude product, which is collected from the low impurity yellow phosphorus collection port 302, and can obtain higher purity yellow phosphorus through conventional refining. The upper liquid is a solution containing residual potassium fluoride (and sodium fluoride), which is used as a hydrolysis solution of potassium fluorosilicate.

4) The furnace gas leaving the fluorine brine spray tower 3 enters the cold water spray tower 4 from the bottom to wash and cool down, use clean water for spraying, and control the amount of clean water sprayed, so that the temperature of the furnace gas tail gas is about 20 ° C; condensation obtains The yellow phosphorus is very little and is in a solid dispersed state, and flows into the cold water collection circulation tank 8 with the water from the bottom of the tower. The solid yellow phosphorus is deposited at the bottom of the cold water collection water circulation tank 8, and is regularly discharged from the high-purity yellow phosphorus collection port 303, heated to a liquid state. Refined to obtain extremely high-purity yellow phosphorus. Finally, the remaining tail gas is sent to the tail gas tank from the yellow phosphorus tail gas outlet 102 through the exhaust fan.

5) The potassium fluorosilicate (sodium) crystal separated by the plate filter is dropped into the reactor 14, and the supernatant (residual potassium fluoride and a small amount of sodium fluoride solution) of the gravity precipitation separator 13 is heated and added. A certain amount of the replacement mother liquor for the subsequent preparation of sodium fluoride) is made into a higher concentration material, reacted for a period of time under the condition of 95～110 ℃, after being filtered by the filter 15, silica is obtained at the silica collection port 106, washed Refined to produce white carbon black; the liquid is potassium fluoride solution (containing a small amount of sodium fluoride).

6) As shown in Figure 3, the hot potassium fluoride solution (containing a small amount of sodium fluoride) filtered by the above-mentioned step filter 15 is sent into the replacement reaction kettle 18 from the potassium fluoride saturated liquid collection port 203, and is fed from sodium carbonate. The metering sodium carbonate that replaces reaction (4) with the potassium fluoride in the kettle is added in the feed port, and then the heat exchanger 19 is cooled to normal temperature for further crystallization, and the sodium fluoride is filtered through the filter 20 to obtain the sodium fluoride crystal product The by-product sodium fluoride crystals are collected at the collection port 109; the filtrate is the replacement mother liquor, which mainly contains potassium carbonate, which can be recycled at the potassium carbonate solution feed port 105 as a reaction raw material for treating potassium fluorosilicate. Other conditions are the same as in Example 1. Wherein, the cooling medium can also be water, the corresponding partition cooling device adopts the partition water cooling device, and the cooling medium conveying equipment is a water pump.

The main product technical indicators of this method are:

Yellow phosphorus product technical indicators: the yield of each quality yellow phosphorus product accounts for 99% of the total phosphorus in the furnace gas leaving the yellow phosphorus electric furnace. Among them, the yield of general industrial yellow phosphorus is 85% (accounting for the mass fraction of the total phosphorus product obtained), the arsenic content is 86 mg/kg, and does not contain silicon impurities; the yield of higher-purity yellow phosphorus is 14% (accounting for the total phosphorus obtained). product mass fraction), the arsenic content is 13mg/kg; the yield of high-purity yellow phosphorus is 1.0% (accounting for the obtained total phosphorus product mass fraction), the arsenic content is below 1.5mg/kg, and does not contain silicon impurities.

Fluorine resources recovery index: The recovery rate of fluorine resources accounts for 90% of the total gas phase escape from the yellow phosphorus electric furnace; the by-product sodium fluoride is about 89.5 kg per ton of yellow phosphorus products produced.

Example 3

A process system and method for multi-quality yellow phosphorus production and its fluorine resource recovery, aiming at a yellow phosphorus electric furnace production device with an output of 10,000 tons/year (annual operating hours of 7200h), wherein the phosphate rock entering the furnace contains phosphorus pentoxide (P ₂ O ₅ ) was 29.8%, the fluorine content was 3%, the gas phase escape rate of fluorine was 15%, and the ratio of raw and auxiliary materials and other operating conditions were the same as those of conventional operations. The yellow phosphorus electric furnace has a gas volume of about 14,000 m ³ /h and a temperature of about 150 °C. The process technology shown in Figure 1, Figure 2 and Figure 3 is used to control the subsequent yellow phosphorus production process and fluorine resource recovery. The specific steps include:

1) The furnace gas at 150°C enters the fluorine-containing salt water spray tower 3 from the bottom from the yellow phosphorus furnace gas inlet 101, and is directly contacted and cooled with the 18% potassium fluoride sprayed from the top of the tower to control the spray amount of potassium fluoride solution. The temperature of the furnace gas leaving the spray tower is about 60 ℃, and the liquid yellow phosphorus, fluorosilicate precipitation, ash and the remaining potassium fluoride solution are condensed and precipitated into the fluorine-containing brine to collect the sedimentation tank 7. The liquid in the tank and the precipitated crystals The particulate mixture is then circulated and sprayed by the fluorine-containing brine circulating pump 10 for use. After the fluorosilicate crystal particles gradually accumulate and grow up and accumulate to a certain amount with the condensed liquid yellow phosphorus and ash, they are discharged, and the solid potassium fluorosilicate (containing a certain amount of fluorosilicate) is separated through the separation device 12 of a three-phase centrifugal separator. The large particle ash content), the liquid is then kept warm and stratified by the gravity sedimentation separator 13, and the bottom is the yellow phosphorus crude product, which is collected from the impurity yellow phosphorus collection port 302, and general industrial yellow phosphorus can be obtained by conventional refining. The upper liquid is a solution containing residual potassium fluoride, which is used as a hydrolysis solution of potassium fluorosilicate.

2) The furnace gas leaving the fluorine brine spray tower 3 enters the cold water spray tower 4 from the bottom to wash and cool down, use clean water for spraying, and control the amount of clean water sprayed, so that the temperature of the furnace gas tail gas is about 20 ℃; condensation obtains The yellow phosphorus is very little and is in a solid dispersed state, and flows into the cold water collection circulation tank 8 with the water from the bottom of the tower. The solid yellow phosphorus is deposited at the bottom of the cold water collection water circulation tank 8, and is regularly discharged from the high-purity yellow phosphorus collection port 303, heated to a liquid state. After refining, high-purity yellow phosphorus can be obtained. Finally, the remaining tail gas is sent to the tail gas tank from the yellow phosphorus tail gas outlet 102 through the exhaust fan.

3) The potassium fluorosilicate crystal separated by the three-phase centrifugal separator is dropped into the reactor 14, the supernatant (residual potassium fluoride and a small amount of sodium fluoride solution) of the gravity precipitation separator 13 is heated, and a certain Amount of subsequent preparation of sodium fluoride replacement mother liquor) is made into a higher concentration material, reacted for a period of time under the condition of 95～110 ℃, after being filtered by the filter 15, silica is obtained at the silica collection port 106, washed and refined Production of white carbon black; the liquid is potassium fluoride solution (containing a small amount of sodium fluoride).

4) as shown in Figure 3, the hot potassium fluoride solution (containing a small amount of sodium fluoride) filtered by the above-mentioned step filter 15 is sent into the replacement reactor 18 from the potassium fluoride saturated liquid collection port 203, The metering sodium carbonate that replaces reaction (4) with the potassium fluoride in the kettle is added in the feed port, and then the heat exchanger 19 is cooled to normal temperature for further crystallization, and the sodium fluoride is filtered through the filter 20 to obtain the sodium fluoride crystal product The by-product sodium fluoride crystals are collected at the collection port 109; the filtrate is the replacement mother liquor, which mainly contains potassium carbonate, which can be recycled at the potassium carbonate solution feed port 105 as a reaction raw material for treating potassium fluorosilicate. The remaining conditions are the same as those in Example 1 and Example 2.

The main product technical indicators of this method are:

Yellow phosphorus product technical indicators: the yield of each quality yellow phosphorus product accounts for 97% of the total phosphorus in the furnace gas leaving the yellow phosphorus electric furnace. Among them, the yield of general industrial yellow phosphorus is 98.5% (accounting for the mass fraction of the total phosphorus product obtained), the arsenic content is 295 mg/kg, and does not contain silicon impurities; the yield of high-purity yellow phosphorus is 1.50% (accounting for the total phosphorus product obtained). mass fraction), arsenic content of 12.5 mg/kg or less, and no silicon impurities.

Fluorine resources recovery index: The recovery rate of fluorine resources accounts for 89% of the total gas phase escape from the yellow phosphorus electric furnace; the by-product sodium fluoride is about 88 kilograms per ton of yellow phosphorus products produced.

The above are only 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 in the protection of the present invention. within the range.

Claims (8)

1. A multi-quality yellow phosphorus production and fluorine resource recovery process system is characterized by comprising the following steps:

the dust remover (1) is provided with a yellow phosphorus furnace gas inlet (101), a yellow phosphorus furnace gas outlet and an ash outlet arranged at the bottom, and the ash outlet is communicated with the semi-sealed ash bin (5);

the dividing wall cooling device is provided with a high-temperature material inlet arranged at the top, a cooling material outlet arranged at the lower part, a condensate discharge port arranged at the bottom, a cooling medium inlet and a cooling medium outlet (104), the yellow phosphorus furnace gas outlet is communicated with the high-temperature material inlet, the cooling medium inlet is sequentially communicated with a cooling medium conveying device (9) and a cooling medium inlet pipe (103), the condensate discharge port is communicated with a water-sealed yellow phosphorus collecting tank (6), the water-sealed yellow phosphorus collecting tank (6) is provided with an industrial yellow phosphorus collecting port (301), and the cooling medium outlet (104) is also communicated with the cooling medium conveying device (9);

the fluorine-containing brine spray tower (3) is provided with a first air inlet, a first air outlet, a first spray head and a potassium fluoride solution collecting port (201) arranged at the bottom, the cooling material outlet is communicated with the first air inlet, the potassium fluoride solution collecting port (201) is communicated with a fluorine-containing brine collecting and precipitating tank (7), the fluorine-containing brine collecting and precipitating tank (7) is provided with a mixed solution collecting port (202) for yellow phosphorus, potassium fluosilicate precipitate and potassium fluoride, and the fluorine-containing brine collecting and precipitating tank (7) is also communicated with the first spray head through a fluorine-containing brine circulating pump (10);

and the cold water spray tower (4) is provided with a second air inlet, a yellow phosphorus tail gas outlet (102), a bottom feed opening and a second spray head, the first air outlet is communicated with the second air inlet, the bottom feed opening is communicated with the cold water collecting and circulating groove (8), the cold water collecting and circulating groove (8) is provided with a high-purity yellow phosphorus collecting opening (303), and is also communicated with the second spray head through a cold water circulating pump (11).

2. The process system for producing high-quality yellow phosphorus and recovering fluorine resources thereof according to claim 1, wherein the system further comprises:

a feed inlet of the separation device (12) is communicated with a mixed liquid collecting port (202) of the yellow phosphorus, the potassium fluosilicate precipitate and the potassium fluoride, a liquid outlet of the separation device is communicated with a gravity settling knockout (13), and the gravity settling knockout (13) is provided with a low-impurity yellow phosphorus collecting port (302);

one feed inlet of the reaction kettle (14) is respectively communicated with a slag outlet of the separation device (12) and a supernatant outlet of the gravity settling liquid separator (13), and the other feed inlet of the reaction kettle is a potassium carbonate solution feed inlet (105);

filter (15), its feed inlet intercommunication the discharge gate of reation kettle (14), its discharge gate passes through valve intercommunication potassium fluoride saturated liquid and collects mouth (203) to still communicate evaporative concentration cooling crystallizer (16) and centrifuge (17) in proper order, the discharge gate intercommunication potassium fluoride solution retrieval and utilization mouth (201) of centrifuge (17) is and still communicates through the valve evaporative concentration cooling crystallizer (16), filter (15) have by-product silicon dioxide and collect mouth (106), centrifuge (17) have by-product potassium fluoride crystal and collect mouth (107).

3. The process system for producing high-quality yellow phosphorus and recovering fluorine resources thereof according to claim 2, wherein the system further comprises:

and one feed inlet of the displacement reaction kettle (18) is communicated with the potassium fluoride saturated liquid collecting port (203), the other feed inlet of the displacement reaction kettle is a sodium carbonate feed inlet (108), the discharge outlet of the displacement reaction kettle is sequentially communicated with a heat exchanger (19) and a sodium fluoride filter (20), and the sodium fluoride filter (20) is provided with a potassium carbonate solution collecting port (105) and a byproduct sodium fluoride crystal collecting port (109).

4. The process system for producing high-quality yellow phosphorus and recovering fluorine resources thereof according to any one of claims 1 to 3, wherein: the cooling medium is normal temperature air or water, correspondingly, the dividing wall cooling device is a dividing wall air cooling device or a dividing wall water cooling device, and the cooling medium conveying equipment (9) is a blower or a water pump; the separation device (12) is a plate filter or a three-phase centrifugal separator.

5. A process method for producing multi-quality yellow phosphorus and recovering fluorine resources thereof is characterized in that the system of any one of claims 1 to 4 is adopted for production, and the process method specifically comprises the following steps:

1) introducing yellow phosphorus electric furnace gas from the yellow phosphorus furnace gas inlet (101) at the temperature of more than 230 ℃, removing dust in the dust remover (1), separating dust, and obtaining yellow phosphorus-removed furnace gas with the temperature of more than 200 ℃ and without dust impurities containing arsenic simple substances; when the temperature of the yellow phosphorus furnace gas introduced from the yellow phosphorus furnace gas inlet (101) is 140-180 ℃, directly introducing the yellow phosphorus furnace gas into the fluorine-containing saline water spray tower (3) to carry out the step 3) and the subsequent steps;

2) introducing the yellow phosphorus-removing furnace gas which is obtained in the step 1) and is used for removing the dust impurities containing the arsenic simple substance and has the temperature of more than 200 ℃ into the partition wall cooling device for air cooling or water cooling, and separating to obtain condensed discharge liquid and SiF containing the arsenic simple substance and having the temperature of 95-120 DEG C₄Furnace gas, collecting and refining the condensation effluent to obtain low-arsenic industrial yellow phosphorus;

3) the SiF-containing material obtained in the step 2)₄Furnace gas is introduced into the fluorine-containing brine spray tower (3) for spraying, the obtained mixed liquid of liquid yellow phosphorus precipitated by condensation, potassium fluosilicate precipitate and potassium fluoride flows into the fluorine-containing brine collection and precipitation tank (7), the mixture of liquid in the tank and precipitated crystal particles can be circulated to the first spray header for spraying through the fluorine-containing brine circulating pump (10), and simultaneously SiF is removed₄Wherein the spray liquid is 3-45% potassium fluoride solution, the temperature is 30-50 ℃, and SiF is removed₄The temperature of furnace gas is 50-60 ℃;

4) will step withThe SiF removal obtained in step 3)₄The furnace gas is introduced into the cold water spray tower (4) for washing and cooling, the cold water mixed liquid dispersed with solid yellow phosphorus is obtained by condensation, meanwhile, yellow phosphorus tail gas is discharged, the water mixed liquid dispersed with the solid yellow phosphorus is precipitated and separated to obtain the solid yellow phosphorus, the yellow phosphorus is refined to obtain high-purity yellow phosphorus, and the supernatant fluid of the precipitate is circulated to a second spray head for spraying by the cold water circulating pump (11), wherein the temperature of the yellow phosphorus tail gas is 10-35 ℃.

6. The process for producing high-quality yellow phosphorus and recovering fluorine resources thereof according to claim 5, further comprising the step 5):

5a) introducing the mixed liquid of the liquid yellow phosphorus, the potassium fluosilicate precipitate, the ash and the potassium fluoride obtained in the step 3) into the separation device (12) for separation, and then carrying out heat preservation, standing and layering on the liquid by the gravity settling knockout (13) to obtain low-impurity yellow phosphorus which can be refined to obtain high-purity yellow phosphorus; in the step 1), the yellow phosphorus furnace gas with the temperature of 140-180 ℃ is not subjected to dust removal, and in the step 2), the obtained yellow phosphorus crude product operated in the step 3) is directly refined to obtain industrial yellow phosphorus;

5b) putting the potassium fluosilicate crystal containing part of ash separated by the separation device (12) into the reaction kettle (14), adding a supernatant obtained by the gravity settling liquid separator (13), heating to 100 ℃ to hydrolyze the potassium fluosilicate crystal into a solution, filtering to remove the ash, adding a replacement mother liquor of potassium carbonate or sodium fluoride to prepare a high-concentration material, reacting at 95-110 ℃, filtering by the filter (15) to obtain silicon dioxide, washing and refining to produce white carbon black, and obtaining a nearly saturated potassium fluoride solution;

5c) and (3) cooling and crystallizing the obtained nearly saturated potassium fluoride solution through the concentration cooling crystallizer (16) to separate out potassium fluoride, dehydrating the solution through the centrifugal machine (17) to obtain a potassium fluoride crystal product, wherein the rest is crystallized mother solution rich in potassium fluoride, one part is used as a supplement solution of a cooling absorption solution potassium fluoride solution, and the other part is sent to the evaporation concentration cooling crystallizer (16) for reuse.

7. The process for producing high-quality yellow phosphorus and recovering fluorine resources thereof according to claim 6, further comprising the step 6): feeding the hot nearly saturated potassium fluoride solution obtained in the step 5b) into the replacement reaction kettle (18), adding sodium carbonate, sodium bicarbonate or sodium hydroxide to perform replacement reaction, cooling to normal temperature through the heat exchanger (19) for crystallization, filtering through the sodium fluoride filter (20) to obtain a sodium fluoride crystal product, wherein the filtrate can be used as the replacement mother liquor of the sodium fluoride.

8. The process for the production of high-quality yellow phosphorus and the recovery of fluorine resources thereof according to any one of claims 5 to 7, wherein: the fluorine salt in the fluorine-containing brine is selected from KF, NaF and NH₄F or HF, fluoride-containing brine, the concentration of KF is 3-45%, the concentration of NaF is 0-5%, and NH₄The concentration of F is 0-15%, and the concentration of HF is 0-15%.

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