TWI788026B - Environmental protection and energy saving recycling system from multiple acid solution and its method - Google Patents

Abstract

An environmental protection and energy saving recycling system from multiple acid solution and its method, the system generates a crystalline first product by inputting the multiple acid solution and a reaction agent into the first product generation section, and generates a precipitated second product by drying the filter fluid separated from the solid liquid of the first product, achieving the purpose of effectively processing and recycling the multiple acid solution containing hydrofluoric acid, the system sets an energy recovery section between the solid-liquid separation section, the first product processing section and the second product generation section, so as to recycle the high temperature steam condensate formed after drying the second product to recycle the filter liquid, and then recycle the cooling distilled water as the cleaning water of the first product crystal, effectively recycling thermal energy and water resources to achieve the purpose of environmental protection and energy saving.

Description

Environment-friendly and energy-saving recycling system and method for generating crystals from multiple acid solutions

The present invention relates to a crystallization process, in particular to an environment-friendly, energy-saving recovery system and method for generating crystals from multiple acid solutions.

High-concentration hydrofluoric acid (containing HF up to 49%) or hydrofluoric acid mixed acid is widely used in etching technology in semiconductor, liquid crystal display panel, solar cell and other technology industries, so the output concentration is as high as 49% or as low as 0.5%. Waste acid solutions containing hydrofluoric acid with various concentrations and large volumes require waste liquid treatment.

The current treatment method of hydrofluoric acid waste liquid is to add calcium-containing compounds such as CaO, Ca(OH) ₂ , CaCl ₂ to react with fluoride ions in waste liquid to form calcium fluoride (CaF ₂ ) sludge cake, or, as invented in Taiwan Patent No. I233428, chemical coagulation of fluoride ions in hydrofluoric acid waste liquid with specific agents is used to remove fluoride ions in waste liquid. However, among the above two methods, the former treatment method has the problems of difficult operation and high cost, and the calcium fluoride sludge cake is not only large in size, but the amount of calcium fluoride whose purity reaches the recovery standard is quite limited, which fails to produce economic benefits ; Although the latter patent can form sodium fluoroaluminate crystals (Na ₃ AlF ₆ , commonly known as cryolite) for recycling, however, the chlorine-containing compound PAC (Polyalumi-num Chloride; polyaluminum chloride) must be used in the chemical coagulation process As a coagulation aid, it further affects the crystallization purity of cryolite. In particular, the cryolite in the prior patent is not produced in a suitable crystallization degree and environment, and the purity is more difficult to meet the standard for recycling.

It is also worth noting that sodium fluoride (NaF) is an ionic compound, which is a colorless crystal or white solid at room temperature and has no odor; it is an important fluoride product, widely used in wood preservatives, wine sterilization Agents, electrolytic aluminum regulators, dental fluorides and other fields. At present, the hydrofluoric acid neutralization method is a commonly used and mature sodium fluoride production process. The hydrofluoric acid neutralization method is to neutralize hydrofluoric acid with sodium hydroxide to obtain sodium fluoride. The reaction formula is as follows: HF+NaOH→NaF+H ₂ O. The production process of conventional sodium fluoride comprises: adding the hydrofluoric acid of concentration 40wt% in the reaction kettle made of lead, then slowly adding sodium hydroxide to neutralize, until the reaction solution is neutral; finally through crystallization, centrifugal dehydration, Dry it to get the sodium fluoride product. This process has the advantages of simple process and stable product quality. However, this process has the problem of serious equipment corrosion, so the requirements for equipment materials are very high, and the neutralization method uses commercially available hydrofluoric acid as raw materials, etc., which lead to The production cost of sodium fluoride is relatively high, and it lacks market competitiveness at the present stage, and needs further improvement.

In view of the conventional technical problems, the first object of the present invention is to provide an environmental protection and energy-saving recovery system and method thereof for generating crystals from multiple acid solutions. The spent acid solution containing hydrofluoric acid is usually a multiple acid solution, that is, contains hydrofluoric acid A solution mixed with one to three acids, and one to two reactive agents are added together to form a crystal-like first product, and the filtrate after solid-liquid separation from the first product is subjected to a drying procedure to form a precipitate-like second product The product achieves the purpose of effectively treating and recycling multiple acid solutions containing hydrofluoric acid.

The second object of the present invention is that the system of the present invention includes a first product generation section, a solid-liquid separation section, and a first product treatment section that generate the first product according to the process sequence, and is connected with the solid-liquid separation section to input the filtrate generation section. The second product generation section of the second product; the system of the present invention sets an energy recovery section between the solid-liquid separation section, the first product treatment section, and the second product generation section to recycle the second product formed after drying High-temperature steam, the thermal energy of the steam is recovered to preheat the filtrate, and the steam is condensed and heat-exchanged to cool down to form low-temperature distilled water, which is used as the cleaning water of the first product for primary recovery, and then formed after cleaning the first product. The filtrate is returned to the energy recovery section for secondary recovery and use; the system of the present invention can effectively recover heat energy and water resources in the process of producing the first product and the second product through the above-mentioned technical solution, and achieve the purpose of environmental protection and energy saving.

The reason is that, in order to achieve the above object, the present invention provides an environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions, which includes: a control processor; the first product generation section is electrically controlled by the control processor to input multiple The acid solution and the reaction agent react to the first product generation section to generate the first product and filtrate; the solid-liquid separation section is connected to the first product generation section and is electrically controlled by the control processor to receive and separate the The first product and the filtrate; the first product processing section, which is connected to the solid-liquid separation section to receive and clean the first product for output and storage; the second product generation section, including the drying equipment electrically controlled by the control processor , so that the filtrate is input into the drying equipment for drying and generates the second product and steam; the energy recovery section includes heat recovery equipment and distilled water collection tank, and the heat recovery equipment is respectively connected with the solid-liquid separation section, the first product treatment section and The drying equipment is connected; the heat recovery equipment is electrically controlled by the control processor to transport the filtrate from the solid-liquid separation section to the drying equipment; the distilled water collection tank is connected to the drying equipment to receive and condense the steam to form High-temperature distilled water; thereby, the high-temperature distilled water is recovered and output to the heat recovery equipment, and the filtrate and the high-temperature distilled water are heat-recovered and preheated in the heat recovery equipment, so that the filtrate is heated and output to the drying equipment, and the high-temperature distilled water is cooled to form Low-temperature distilled water, the low-temperature distilled water is recovered and output to the first product processing section to clean the first product.

The present invention also provides an environmental protection and energy-saving recovery method for crystals generated from multiple acid solutions, wherein the steps of the method include:

The first product generation step: input the multiple acid solution and the reaction agent into the first product generation section for crystallization reaction to generate the first product;

Solid-liquid separation step: obtain the first product and filtrate through solid-liquid separation; and output the first product to the first product processing section;

The second product generation step: make the filtrate flow through the heat recovery equipment and then output to the drying equipment, the filtrate is heated by the drying equipment to remove water and crystallize to obtain the second product output storage, and the removed water forms steam output;

Heat energy recovery and preheating step: cooling the steam to form high-temperature distilled water, which is recovered and output to the heat recovery equipment, and the filtrate and the high-temperature distilled water are heat-exchanged in the heat recovery equipment to recover heat energy and preheat the filtrate; High-temperature distilled water is cooled to form low-temperature distilled water;

The first product cleaning step: recovering the low-temperature distilled water as cleaning water to output and wash the first product, and output and store the first product after cleaning.

Regarding the technology, means and other effects adopted by the present invention to achieve the above-mentioned purpose, preferred feasible embodiments are given and described in detail in conjunction with the drawings as follows.

In order to facilitate the understanding of the present invention, the following description will be made in conjunction with FIG. 1 , FIG. 2 and the embodiments.

As shown in Figure 1, the environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions provided by the present invention is used to treat waste liquids containing hydrofluoric acid (HF) and 1 to 3 kinds of mixed acids. The waste liquid is mixed and reacted to achieve the purpose of removing hydrofluoric acid. In the embodiment of the present invention, the waste liquid is defined as multiple acid solution A, and the external agent is reaction agent B, wherein, the multiple acid solution A contains hydrofluoric acid (HF) and a combination of one to three acids selected from the following: nitric acid (HNO ₃ ), phosphoric acid (H ₃ PO ₄ ), hydrochloric acid (HCl) and sulfuric acid (H ₂ SO ₄ ), the reagent B is selected from the following combination of one or two compounds: calcium chloride (CaCl ₂ ), calcium oxide (CaO), calcium hydroxide (Ca(OH) ₂ ), calcium carbonate (CaCO ₃ ), calcium sulfate (CaSO ₄ ), sodium aluminate (NaAlO ₂ ), sodium silicate (Na ₂ SiO ₃ ) and sodium hydroxide (NaOH).

Specifically, the system of the present invention includes a control processor 60 and a first product generation section 10, a solid-liquid separation section 20, a first product processing section 30, a second product generation section 40 and an energy source controlled by the control processor 60 and set according to the process. Recovery section 50, wherein the solid-liquid separation section 20 is connected between the first product generation section 10 and the first product treatment section 30 to filter out the first product P1, and the solid-liquid separation section 20 further passes through the The energy recovery section 50 is connected with the second product generation section 40 , and the energy recovery section 50 is connected with the first product treatment section 30 , forming a heat energy and water resource recovery path. In this way, the multiple acid solution A and the reaction agent B are controlled by the control processor 60 to be input into the first product generation section 10 for reaction to generate the first product P1 and the remaining reaction solution, and the first product P1 and the remaining reaction solution pass through the The solid-liquid separation section 20 separates and forms the crystallized first product P1 and filtrate FL and transports them to the first product processing section 30 and the second product generation section 40 respectively; Use the low-temperature distilled water LDW recovered by the energy recovery section 50 to clean; the filtrate FL first flows through the energy recovery section 50 to be preheated by the recovered high-temperature distilled water HDW, and then enters the second product generation section 40 for drying to generate a second product P2, so as to realize the effect of effectively treating and recycling the multiple acid solution A containing hydrofluoric acid, and at the same time, effectively recover heat energy and water resources in the waste liquid treatment process to achieve the effect of environmental protection and energy saving.

In the system embodiment of the present invention, the first product generation section 10 is used to input the multiple acid solution A and the reaction agent B to the first product generation section 10; the solid-liquid separation section 20 is used to receive and separate the first The product P1 and the filtrate FL; the first product processing section 30 is used to receive and clean the first product P1 for output and storage; the second product generation section 40 includes a drying device 41 electrically controlled by the control processor 60, To make the filtrate FL input to the drying equipment 41 for drying and generate the second product P2 and steam VP; the energy recovery section 50 includes a heat recovery equipment 51 and a distilled water collection tank 52, and the heat recovery equipment 51 is connected with the solid-liquid separation section respectively 20. The first product processing section 30 is connected to the drying equipment 41; the heat recovery equipment 51 is electrically controlled by the control processor 60 to transport the filtrate FL from the solid-liquid separation section 20 to the drying equipment 41; the The distilled water collection tank 52 is connected with the drying device 41 to receive and condense the steam VP to form high-temperature distilled water HDW; thereby, the high-temperature distilled water HDW is recovered and output to the heat recovery device 51, and the filtrate FL and the high-temperature distilled water HDW are combined in the heat The recovery device 51 performs heat exchange, so that the filtrate FL is output to the drying device 41 after being preheated by the high-temperature distilled water HDW, and the high-temperature distilled water HDW is cooled to form a low-temperature distilled water LDW, which is recovered and output to the second A product treatment section 30 cleans the first product P1.

In the embodiment of the present invention, the heat recovery device 51 is a heat exchanger, and the structure can be a double-tube heat exchanger, a shell-and-tube heat exchanger, a coil heat exchanger or a plate heat exchanger.

In the embodiment of the present invention, a condenser (not shown) is provided between the drying equipment 41 and the distilled water collection tank 52 to condense the high-temperature steam VP generated after the drying equipment 41 is heated to form high-temperature distilled water HDW.

Specifically, as shown in Figure 1, the first product generation section 10 is provided with a multiple acid collection tank 11 and a dosing reaction tank 12, and the multiple acid solution A is input to the multiple acid collection tank 11 to concentrate and then output to the dosing reaction tank 12. The reaction reagent B is input into the dosing reaction tank 12 to react with the multiple acid solution A to generate the first product P1.

Specifically, as shown in Figure 1, the first product generation section 10 is also provided with a buffer tank 13, which is connected between the dosing reaction tank 12 and the solid-liquid separation section 20, so that the multiple acid solution A and The reaction agent B is transported into the buffer tank 13 and fully mixed to react to generate the first product P1.

Specifically, as shown in Figure 1, the solid-liquid separation section 20 is provided with a first dehydration device 21 and a filtrate collection tank 22; the multiple acid solution A reacts with the reaction agent B to generate the first product P1 and the initial filtrate FL1; A dehydration device 21 is connected with the first product generation section 10 to receive and separately transport the first product P1 to the first product treatment section 30 , and separately transport the primary filtrate FL1 to the filtrate collection tank 22 .

In the embodiment of the present invention, the first product generation section 10 is also provided with a buffer water tank 13, which is connected between the dosing reaction tank 12 and the first dehydration device 21, so that the multiple acid solution A and The reaction agent B is transported into the buffer tank 13 and fully mixed to react to generate the first product P1.

Specifically, as shown in Figure 1, the first product processing section 30 includes a first product collection tank 31, a first product cleaning tank 32 and a first product storage tank 33; the first product collection tank 31 and the first dehydration device 21 Connect to concentrate the first product P1 and output it to the first product cleaning tank 32; the first product cleaning tank 32 is connected to the heat recovery device 51, and the low-temperature distilled water LDW produced by the heat recovery device 51 is recovered and output to the second product cleaning tank 32. A product cleaning tank 32 is used as cleaning water to wash the first product P1; the first product P1 is output to the first product storage tank 33 after being cleaned in the first product cleaning tank 32 for storage; thereby, the system of the present invention forms the The low-temperature distilled water LDW is used as the primary recycling path of cleaning water: heat recovery equipment 51 → low-temperature distilled water LDW → first product cleaning tank 32 .

Specifically, as shown in Fig. 1, the first product cleaning tank 32 is connected to the filtrate collection tank 22, and the low-temperature distilled water LDW forms the secondary filtrate FL2 after cleaning the first product P1 in the first product cleaning tank 32, and is recovered and exported to the first product cleaning tank 32. Filtrate collection tank 22 , the secondary filtrate FL2 is mixed with the primary filtrate FL1 to form the filtrate FL, which is then output to the heat recovery device 51 . In this way, the system of the present invention forms a secondary recovery and use path after the low-temperature distilled water LDW forms the secondary filtrate FL2: first product cleaning tank 32→secondary filtrate FL2→filtrate collection tank 22.

Specifically, as shown in FIG. 1 , the energy recovery section 50 also includes a discharge tank 53 connected to the distilled water collection tank 52 for centralized discharge of the high-temperature distilled water HDW.

Specifically, as shown in FIG. 1 , the second product generation section 40 further includes a second product storage tank 42 connected to the drying device 41 to centrally store the second product P2.

In addition, as shown in FIG. 2 , it shows a schematic diagram of another process architecture implementation of the environmental protection and energy saving recovery system for generating crystals from multiple acid solutions according to the present invention. The difference between the system process architecture of Fig. 2 and Fig. 1 is that a second dehydration device 321 is added between the first product cleaning tank 32, the first product storage tank 33 and the filtrate collection tank 22, specifically, the first product processing section 30 also includes a second dehydration device 321 connected between the first product collection tank 32 and the filtrate collection tank 22 and the first product storage tank 33, so that the first product cleaning tank 32 outputs the secondary filtrate FL2 and cleans After the first product P1 to the second dehydration device 321, the second dehydration device 321 separates and transports the cleaned first product P1 to the first product storage tank 33, and separates and transports the secondary filtrate FL2 to the filtrate The collecting tank 22, thereby, achieves solid-liquid separation of the first product P1 and the secondary filtrate FL2.

The above describes the specific implementation of the environmental protection and energy saving recovery system of the present invention for generating crystals from multiple acid solutions. Please refer to Figure 1 and Figure 2 below to illustrate the environmental protection and energy saving recovery method of the present invention for generating crystals from multiple acid solutions.

The steps of the environmental protection and energy-saving recovery method of generating crystals from multiple acid solutions of the present invention include:

The first product generation step: input the multiple acid solution A and the reaction reagent B into the first product generation section 10 for crystallization reaction to generate the first product P1;

Solid-liquid separation step: obtain the first product P1 and filtrate FL through solid-liquid separation; and output the first product P1 to the first product processing section 30;

The second product generation step: make the filtrate FL flow through the heat recovery equipment 51 and then output to the drying equipment 41, the filtrate FL is heated by the drying equipment 41 to remove water and crystallize to obtain the second product P2 output storage, and the removed moisture forms steam VP output;

Heat recovery and preheating step: cooling the steam VP to form high-temperature distilled water HDW, which is recovered and output to the heat recovery device 51, and the filtrate FL and the high-temperature distilled water HDW are exchanged in the heat recovery device 51 to recover heat energy And preheat the filtrate FL; the high-temperature distilled water HDW is cooled to form low-temperature distilled water LDW;

The first product cleaning step: recovering the low-temperature distilled water LDW as cleaning water to output and wash the first product P1, and the first product P1 is output and stored after cleaning.

In the method embodiment of the present invention, the first product cleaning step further includes, the low-temperature distilled water LDW washes the first product P1 to form a secondary filtrate FL2, and the secondary filtrate FL2 recovers the filtrate produced in the solid-liquid separation step FL is mixed to be output to the heat recovery device 51 for reuse.

Please refer to Table 1 below to illustrate the embodiment 1 to embodiment 6 in which the system of the present invention inputs a solution containing hydrofluoric acid mixed with one to three acids (multiple acid solution A) and adds one to two kinds of reagent B for reaction.

It should be understood that, among the compositions of multiple acid solutions A listed in Examples 1 to 6 of the present invention, hydrofluoric acid (HF) is the main treatment target, and other mixed acids (for example: HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ) is a small amount of acid mixed in the multiple acid solution A, and when specifically applied to the system and method of the present invention, the multiple acid solution A can be a mixed solution of two acids (hydrofluoric acid (HF) mixed with another acid ), or a mixed solution of three to four acids (hydrofluoric acid (HF) mixed with another two to three acids).

Table 1: Example Multiple Acid Solution A Reactant B First product P1 Second product P2 1 HF CaCl ₂ NaOH CaF ₂ Ca(NO ₃ ) ₂ CaSO ₄ Ca ₂ (PO ₄ ) ₂ NaCl HNO _{3 H2SO4 _} H ₃ PO ₄ 2 HF Ca(OH) ₂ CaF ₂ Ca(NO ₃ ) ₂ CaSO ₄ Ca ₂ (PO ₄ ) ₂ HNO _{3 H2SO4 _} H ₃ PO ₄ 3 HF CaCO ₃ NaOH CaF ₂ Ca(NO ₃ ) ₂ CaSO ₄ Ca ₂ (PO ₄ ) ₂ Na ₂ CO ₃ HNO _{3 H2SO4 _} H ₃ PO ₄ 4 HF NaAlO ₂ NaOH Na ₃ AlF ₆ NaNO ₃ Na ₂ SO ₄ Na ₃ PO ₄ HNO _{3 H2SO4 _} H ₃ PO ₄ 5 HF Na ₂ SiO ₃ NaOH Na ₂ SiF ₆ NaNO ₃ Na ₂ SO ₄ Na ₃ PO ₄ HNO _{3 H2SO4 _} H ₃ PO ₄ 6 HF NaOH NaF NaNO ₃ Na ₂ SO ₄ Na ₃ PO ₄ HNO _{3 H2SO4 _} H ₃ PO ₄

Example 1:

In Example 1, the multiple acid solution A contains HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B contains CaCl ₂ , NaOH. The chemical reaction formula of multiple acid solution A and reagent B is as follows: CaCl ₂ + 2HF → CaF ₂ + 2HCl; HCl + NaOH → NaCl + H ₂ O; CaCl ₂ + 2HNO ₃ → Ca(NO ₃ ) ₂ + 2HCl; HCl + NaOH → NaCl + H ₂ O; CaCl ₂ + H ₂ SO ₄ → CaSO ₄ + 2HCl; HCl + NaOH → NaCl + H ₂ O; 3CaCl ₂ + 2H ₃ PO ₄ → Ca ₂ (PO ₄ ) ₂ + 6HCl; HCl + NaOH → NaCl + _H2O .

In this embodiment, the constituent acids (HF and other mixed acids) of the multiple acid solution _A react with CaCl in the reagent B to form calcium-containing salts and HCl, and HCl reacts with NaOH in the reagent B to form NaCl and water to finally obtain the first product P1: CaF ₂ crystals, and the second product P2: precipitates including Ca(NO ₃ ) ₂ , CaSO ₄ , Ca ₂ (PO ₄ ) ₂ , and NaCl.

Example 2:

In Example 2, the multiple acid solution A contains HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B contains Ca(OH) ₂ . The chemical reaction formula of multiple acid solution A and reagent B is as follows: Ca(OH) ₂ + HF → CaF ₂ + 2H ₂ O ; Ca(OH) ₂ + HNO ₃ → Ca(NO ₃ ) ₂ + 2H ₂ O ; (OH) ₂ + H ₂ SO ₄ → CaSO ₄ + 2H ₂ O ; 3Ca(OH) ₂ + 2H ₃ PO ₄ → Ca ₂ (PO ₄ ) ₂ + 6H ₂ O .

In this embodiment, the constituent acids (HF and other mixed acids) of the multiple acid solution _A respectively react with Ca(OH) in the reagent B to form calcium-containing salts and water, and finally obtain the first product P1: CaF ₂ crystals, and the second product P2: precipitates including Ca(NO ₃ ) ₂ , CaSO ₄ , Ca ₂ (PO ₄ ) ₂ .

Example 3:

In Example 3, the multiple acid solution A contains HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B contains CaCO ₃ , NaOH. The chemical reaction formula of multiple acid solution A and reagent B is as follows: CaCO ₃ + 2HF → CaF ₂ + H ₂ CO ₃ ; H ₂ CO ₃ + 2NaOH → Na ₂ CO ₃ + 2H ₂ O; CaCO ₃ + 2HNO ₃ → Ca (NO ₃ ) ₂ + H ₂ CO ₃ ; H ₂ CO ₃ + 2NaOH → Na ₂ CO ₃ + 2H ₂ O; CaCO ₃ + H ₂ SO ₄ → CaSO ₄ + HCO ₃ ; H ₂ CO ₃ + 2NaOH → Na ₂ CO ₃ + 2H ₂ O; 3CaCO ₃ + 2H ₃ PO ₄ → Ca ₂ (PO ₄ ) ₂ + 3HCO ₃ ; H ₂ CO ₃ + 2NaOH → Na ₂ CO ₃ + 2H ₂ O.

In this embodiment, the constituent acids (HF and other mixed acids) of the multiple acid solution A react with CaCO ₃ in the reagent B to form calcium-containing salts and HCO ₃ , and HCO ₃ reacts with NaOH in the reagent B The reaction forms Na ₂ CO ₃ and water, and finally obtains the first product P1: CaF ₂ crystals, and the second product P2: including Ca(NO ₃ ) ₂ , CaSO ₄ , Ca ₂ (PO ₄ ) ₂ , Na ₂ CO ₃ Precipitate.

Example 4:

In Example 4, the multiple acid solution A includes HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B includes NaAlO ₂ , NaOH. The chemical reaction formula of multiple acid solution A and reagent B is as follows: n Na ₂ O‧Al ₂ O ₃ + 2(n+3)HF → 2(n NaF‧AlF ₃ ) + (n+3)H ₂ O ; NaOH + HNO ₃ → NaNO ₃ + H ₂ O ; 2NaOH + H ₂ SO ₄ → Na ₂ SO ₄ + 2H ₂ O ; 3NaOH + 2H ₃ PO ₄ → Na ₃ PO ₄ + 3H ₂ O .

In this embodiment, the HF in the multiple acid solution A reacts with the NaAlO ₂ in the reagent B to form Na ₃ AlF ₆ and water, and the HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ in the multiple acid solution A react with the reagent B NaOH in B reacts to form sodium-containing salts and water, and finally obtains the first product P1: Na ₃ AlF ₆ (cryolite) crystals, and the second product P2: NaNO ₃ , Na ₂ SO ₄ , Na ₃ PO ₄ Precipitate.

Example 5:

In Example 5, the multiple acid solution A includes HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B includes Na ₂ SiO ₃ , NaOH. The chemical reaction formula of multiple acid solution A and reagent B is as follows: Na ₂ SiO ₃ + HF → Na ₂ SiF ₆ + H ₂ SiF ₆ + H ₂ O; H ₂ SiF ₆ + 2NaOH → Na ₂ SiF ₆ + 2H ₂ O ; NaOH + HNO ₃ → NaNO ₃ + H ₂ O; 2NaOH + H ₂ SO ₄ → Na ₂ SO ₄ + 2H ₂ O ; 3NaOH + 2H ₃ PO ₄ → Na ₃ PO ₄ + 3H ₂ O.

In this embodiment, the HF in the multiple acid solution A reacts with the Na ₂ SiO ₃ in the reagent B to form Na ₂ SiF ₆ and water, and the HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ in the multiple acid solution A and The NaOH in the reaction agent B reacts to form sodium-containing salts and water, and finally obtains the first product P1: Na ₂ SiF ₆ crystals, and the second product P2: precipitates including NaNO ₃ , Na ₂ SO ₄ , and Na ₃ PO ₄ .

Embodiment 6:

In Example 5, the multiple acid solution A contains HF, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ ; the reagent B contains NaOH. The chemical reaction formula of multiple acid solution A and reagent B is as follows: NaOH + HF → NaF + H ₂ O ; NaOH + HNO ₃ → NaNO ₃ + H ₂ O ; 2NaOH + H ₂ SO ₄ → Na ₂ SO ₄ + 2H ₂ O ; 3NaOH + 2H ₃ PO ₄ → Na ₃ PO ₄ + 3H ₂ O .

In this embodiment, the constituent acids (HF and other mixed acids) of the multiple acid solution A react with NaOH in the reagent B to form sodium-containing salts and water, and finally obtain the first product P1: NaF crystals, and the second product P2: Precipitates including NaNO ₃ , Na ₂ SO ₄ , Na ₃ PO ₄ .

A: Multiple acid solution B: Reactive Potion 10: The first product generation segment 11: Multiple acid collection tank 12: Dosing reaction tank 13: buffer tank FL: filtrate FL1: primary filtrate P1: first product 20: Solid-liquid separation section 21: The first dehydration equipment 22: Filtrate collection tank 30: The first product processing section 31: The first product collection tank 32: The first product cleaning tank 321: The second dehydration equipment 33: First product storage tank 40: The second product generation segment 41: Drying equipment 42: Second product storage tank VP: Steam P2: Second product 50: Energy recovery section 51:Heat recovery equipment 52: Distilled water collection tank 53: Release sink DW: distilled water DW HDW: high temperature distilled water LDW: low temperature distilled water FL2: secondary filtrate 60: Control Processor

Fig. 1 is the schematic diagram of the process structure of the environmental protection and energy saving recycling system of the present invention to generate crystals from multiple acid solutions; FIG. 2 is a schematic diagram of another implementation of the process architecture of the system of the present invention.

A: Multiple acid solution

B: Reactive Potion

10: The first product generation segment

11: Multiple acid collection tank

12: Dosing reaction tank

13: buffer tank

FL: filtrate

FL1: primary filtrate

P1: first product

20: Solid-liquid separation section

21: The first dehydration equipment

22: Filtrate collection tank

30: The first product processing section

31: The first product collection tank

32: The first product cleaning tank

33: First product storage tank

40: The second product generation segment

41: Drying equipment

42: Second product storage tank

VP: Steam

P2: Second product

50: Energy recovery section

51:Heat recovery equipment

52: Distilled water collection tank

53: Release sink

DW: distilled water DW

HDW: high temperature distilled water

LDW: low temperature distilled water

FL2: secondary filtrate

60: Control Processor

Claims (11)

An environment-friendly and energy-saving recovery system for generating crystals from multiple acid solutions, including: a control processor; a first product generation section, electrically controlled by the control processor, to input multiple acid solutions and reactants to the first product generation section for processing React and generate the first product and filtrate; wherein, the multiple acid solution comprises hydrofluoric acid and a combination of one to three acids selected from the following: nitric acid, phosphoric acid, hydrochloric acid and sulfuric acid; wherein the reactant is selected from the following one to two compounds Combination: calcium chloride, calcium oxide, calcium hydroxide, calcium carbonate, calcium sulfate, sodium aluminate, sodium silicate and sodium hydroxide; solid-liquid separation section, connected with the first product generation section and controlled by the processor Electrically controlled to receive and separate the first product and the filtrate; the first product processing section is connected to the solid-liquid separation section to receive and clean the first product and output it for storage; the second product generation section includes the The drying equipment electrically controlled by the control processor, so that the filtrate is input into the drying equipment for drying and generating the second product and steam; the energy recovery section includes heat recovery equipment and distilled water collection tank, and the heat recovery equipment is separated from the solid-liquid Section, the first product processing section and the drying equipment are connected; the heat recovery equipment is electrically controlled by the control processor to transport the filtrate from the solid-liquid separation section to the drying equipment; the distilled water collection tank is connected to the drying equipment Connect to receive and condense the steam to form high-temperature distilled water; thereby, the high-temperature distilled water is recovered and output to the heat recovery equipment, and the filtrate and the high-temperature distilled water are heat recovered and preheated in the heat recovery equipment, so that the filtrate is heated and output to the heat recovery equipment Drying equipment, the high-temperature distilled water is cooled to form low-temperature distilled water, and the low-temperature distilled water is recovered and output to the first product processing section to clean the first product. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 1, wherein the first product generation section is provided with multiple acid collection tanks and dosing reaction tanks, and the multiple acid solutions are input into the multiple acid collection tanks After being concentrated, it is output to the dosing reaction tank, and the reagent is output into the dosing reaction tank to react with the multiple acid solution to generate the first product. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 2, wherein the first product generation section is also provided with a buffer water tank, and the buffer water tank is connected between the dosing reaction tank and the solid-liquid separation section During this time, the multiple acid solution and the reaction agent are transported into the buffer water tank and fully mixed to react to form the first product. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 1, wherein the solid-liquid separation section is provided with a first dehydration device and a filtrate collection tank; the multiple acid solution reacts with the reactant to generate the first product and primary filtrate; the first dehydration equipment is connected to the first product generation section to receive and separately transport the first product to the first product treatment section, and separately transport the primary filtrate to the filtrate collection tank. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 4, wherein the first product processing section includes a first product collection tank, a first product cleaning tank and a first product storage tank; the first product The collection tank is connected to the dehydration equipment to concentrate the first product and then output to the first product cleaning tank; the first product cleaning tank is connected to the heat recovery equipment, and the low-temperature distilled water produced by the heat recovery equipment is recycled and output to the first product cleaning tank. A product cleaning tank is used as cleaning water to wash the first product; the first product is output to the first product storage tank for storage after being cleaned in the first product cleaning tank. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 5, wherein the first product cleaning tank is connected to the filtrate collection tank, and the low-temperature distilled water is used in the first product After cleaning the first product in the product cleaning tank, the secondary filtrate is recovered and output to the filtrate collection tank, and the secondary filtrate is mixed with the primary filtrate to form the filtrate, which is then output to the heat recovery device. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 6, wherein the first product processing section also includes a second dehydration device connected to the first product collection tank and the filtrate collection tank and the first Between the product storage tanks, the first product cleaning tank outputs the secondary filtrate and the cleaned first product to the second dehydration equipment, and the second dehydration equipment separates and transports the cleaned first product to the first product storage tank, and separate and transport the secondary filtrate to the filtrate collection tank. The environmental protection and energy-saving recovery system for generating crystals from multiple acid solutions as described in claim 1, wherein the energy recovery section further includes a discharge water tank connected to the distilled water collection tank for centralized discharge of the high-temperature distilled water. The environment-friendly and energy-saving recycling system for generating crystals from multiple acid solutions as described in Claim 1, wherein the second product generation section further includes a second product storage tank connected to the drying equipment for centralized storage of the second product. An environmentally friendly and energy-saving recovery method for crystals generated from multiple acid solutions, the steps of the method include: first product generation step: input multiple acid solutions and reaction agents into the first product generation section for crystallization reaction to generate the first product; wherein, the The multiple acid solution contains hydrofluoric acid and a combination of one to three acids selected from the following: nitric acid, phosphoric acid, hydrochloric acid and sulfuric acid; wherein, the reactant is selected from the combination of one to two compounds below: calcium chloride, calcium oxide, calcium hydroxide , calcium carbonate, calcium sulfate, sodium aluminate, sodium silicate and sodium hydroxide; solid-liquid separation step: obtain the first product and filtrate through solid-liquid separation; and output the first product to the first product processing section; The second product generation step: let the filtrate flow through the heat recovery equipment and then output to the drying equipment, the filtrate is heated by the drying equipment to remove water and crystallize to obtain the second product output storage, and the removed water forms steam output; heat energy recovery preheating Steps: cooling the steam to form high-temperature distilled water, recovering and outputting the high-temperature distilled water to the heat recovery equipment, exchanging heat between the filtrate and the high-temperature distilled water in the heat recovery equipment to recover heat energy and preheating the filtrate; cooling down the high-temperature distilled water Low-temperature distilled water is formed; the first product cleaning step: the low-temperature distilled water is recovered as cleaning water to output and wash the first product, and the first product is output and stored after cleaning. The environmental protection and energy-saving recovery method for crystals generated from multiple acid solutions as described in claim 10, wherein, in the first product cleaning step, the low-temperature distilled water washes the first product to form a secondary filtrate, and the secondary filtrate recovery is related to the The filtrate produced in the solid-liquid separation step is mixed to be output to the heat recovery device for reuse.

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