Production device and production process for preparing high-purity humic acid by utilizing flocculation technology

Abstract

The invention relates to a production device and a production process for preparing high-purity humic acid by utilizing a flocculation technology. Comprising a raw material storage tank and a high-purity humic acid product storage tank, the raw material storage tank is connected with a high-concentration hard water flocculation reaction unit through a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected with the high-purity humic acid product storage tank through a sulfurous acid reduction reaction unit and a high-purity humic acid treatment unit in sequence; according to the present invention, the pH value does not need to be detected and regulated all the time during the production process so as to reduce the operation difficulty, the strong acid is not used so as to achieve the purpose of weak acidity of the product, and the harm to the equipment and the operator can be further avoided.

Description

Technical Field

[0001] The invention relates to the technical field of high-purity humic acid production, and in particular to a production device and a production process for preparing high-purity humic acid by utilizing flocculation technology. Background Art

[0002] At present, the commonly used production process of high-purity humic acid mainly adopts the alkali dissolution and acid precipitation method. For example, the Chinese patent announcement number is CN101033241B, and the patent name is: A method for preparing high-purity humic acid, which discloses the following steps for preparing high-purity humic acid, namely: (1) extracting humic acid from coal with an alkali solution, adding a coagulant, centrifuging and removing slag to obtain humic acid sodium salt; (2) adding a complexing agent under acidic conditions to remove high-valent cations; (3) removing inorganic salts and soluble complex ions in the colloidal system by electrodialysis after acidification; (4) obtaining humic acid powder with a purity of ≥95% after drying. In short, in traditional technology, high-purity humic acid is produced by the alkali dissolution and acid precipitation method. First, the raw coal is reacted with a caustic soda / potassium solution and then centrifuged to obtain a humic sodium / potassium solution. Then, a strong acid such as hydrochloric acid is used to adjust the pH to 1-3, and the humic acid insoluble in acid will precipitate. Subsequently, separation, water washing or electrodialysis, and drying are performed to obtain high-purity humic acid. The above method has the following defects: 1. Since high-purity humic acid is prepared under strong acid conditions, the product is highly acidic, and the general pH value is 1-3; it is not only harmful to crops, but also easy to accelerate soil acidification and salinization; 2. The entire preparation process is relatively cumbersome and complicated, especially the amount of acid used in acid precipitation is directly related to the amount of alkali used, the system pH needs to be paid attention to at all times, it is not easy to adjust, it is very easy to fluctuate, and the product quality is extremely difficult to stabilize; 3. The acid used in the production acid precipitation process is mostly hydrochloric acid, and the acid mist generated in the neutralization process is highly corrosive, which is extremely corrosive to metal equipment, and is also extremely harmful to operators. It is extremely difficult to handle, and the residual acid is not easy to handle, the environmental pollution is large, and the production risk is high. Summary of the invention

[0003] The purpose of the present invention is to provide a production device and a production process for preparing high-purity humic acid using flocculation technology to overcome the defects in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A production device for preparing high-purity humic acid using flocculation technology comprises a raw material storage tank and a high-purity humic acid product storage tank. The raw material storage tank is connected to a high-concentration hard water flocculation reaction unit via a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank via a sulfite reduction reaction unit and a high-purity humic acid processing unit.

[0006] The beneficial effects of the present invention are as follows: the present invention abandons the method of using acid to precipitate humic acid in the prior art, and utilizes the characteristics of humic acid colloid and complex divalent metal ion precipitation, and adopts flocculation technology, using high-concentration hard water to directly strip the humic acid flocculation from the system; further, utilizing the characteristic that sulfurous acid is stronger than humic acid, sulfurous acid is used when reducing humic acid, and excessive sulfur dioxide is added to generate soluble calcium / magnesium hydrogen sulfite, so that only humic acid precipitation remains in the system, and a high-purity humic acid product can be obtained after washing and purification; in the above process, there is no need to adjust the pH value to achieve the characteristic of reducing the difficulty of operation, and the sulfurous acid used is a weak acid, the pH value of the system is only between 3 and 5, and sulfur dioxide is gaseous and soluble in water, and will not remain in the humic acid product to achieve the purpose of making the product weakly acidic, and further, it can avoid the characteristic of harming equipment and operators.

[0007] Preferably, the humate refining unit comprises a raw material reactor, the inlet of which is respectively connected to a raw material storage tank, an alkali solution storage tank and a desalted water pipeline, the outlet of which is connected to a crude humate solution storage tank, and the crude humate solution storage tank is connected to a refined humate solution storage tank via a horizontal screw centrifuge.

[0008] Preferably, the outlet of the refined humate solution storage tank in the humate refining unit is connected to the middle inlet of the flocculation reaction tank, the top inlet of the flocculation reaction tank is connected to the high-concentration hard water storage tank, the bottom outlet of the high-concentration hard water storage tank is connected to the first plate and frame filter press, and the solid phase outlet of the first plate and frame filter press is connected to the calcium / magnesium humate temporary storage tank.

[0009] Preferably, the outlet of the calcium / magnesium humate temporary storage tank is connected to the sulfite solution storage tank in the sulfite reduction reaction unit, the gas phase inlet of the sulfite solution storage tank is connected to the sulfur dioxide gas tank, and the outlet of the sulfite solution storage tank is connected to the second plate and frame filter press.

[0010] Preferably, the liquid phase outlet of the first plate and frame filter press is connected to a high-concentration hard water storage tank through a filter.

[0011] Preferably, the outlet of the calcium / magnesium humate temporary storage tank is also connected to the calcium / magnesium humate product storage tank through a first dryer.

[0012] Preferably, the solid phase outlet of the second plate and frame filter press is connected to a high-purity humic acid product storage tank via a water washing device and a second dryer.

[0013] Preferably, the liquid phase outlet of the second plate and frame filter press and the liquid phase outlet of the water washing device are respectively connected to the calcium bisulfite / magnesium solution storage tank, the outlet of the calcium bisulfite / magnesium solution storage tank is connected to the dilute hydrochloric acid solution storage tank, the gas phase outlet of the dilute hydrochloric acid solution storage tank is connected to the inlet of the sulfur dioxide gas tank, and the liquid phase outlet of the dilute hydrochloric acid solution storage tank is connected to the high-concentration hard water storage tank through a filter.

[0014] The present invention also provides a production process for preparing high-purity humic acid by using flocculation technology. The production process is as follows: raw coal in a raw material storage tank enters a humate refining unit, humic acid in the raw coal is extracted by alkali solution to obtain a humate solution, the property of humic acid complexing divalent metal ions to form a precipitate is utilized, and a high-concentration hard water flocculation reaction unit is used to flocculate the humate solution with high-concentration calcium and magnesium ions to obtain a humate calcium-magnesium intermediate product; the above-mentioned humate calcium-magnesium intermediate product enters a sulfite reduction reaction unit for reduction reaction to obtain a calcium-magnesium sulfite precipitate, and excess sulfur dioxide is used to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium hydrogen sulfite, and finally a high-purity humic acid product is obtained by water washing and drying in a high-purity humic acid treatment unit, and enters a high-purity humic acid product storage tank.

[0015] The present invention also provides a production process for preparing high-purity humic acid using flocculation technology, and the production process comprises the following steps:

[0016] Step 1: The raw coal in the raw material storage tank enters the raw material reactor, and the alkali liquid storage tank and the desalted water pipeline respectively add alkali liquid and desalted water into the raw material reactor, so that the mass ratio of the raw material coal, alkali and water is 8-10:1:30, and the raw material reactor is heated to 120-160°C and reacted for 2 hours;

[0017] Step 2: sending the reaction liquid after the reaction in the above raw material reactor to a crude humate solution storage tank for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank to a horizontal screw centrifuge for centrifugal treatment, and sending the centrifuged liquid to a refined humate solution storage tank for temporary storage;

[0018] Step 3: The centrifugal liquid in the refined humate solution storage tank enters the flocculation reaction tank, and at the same time, the high-concentration hard water with a hardness of 150 to 200 in the high-concentration hard water storage tank is sent to the flocculation reaction tank. The reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate and frame filter press for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 20 to 30:1;

[0019] Step 4: The filter cake after filtration by the first plate and frame filter press is calcium / magnesium humate, which is temporarily stored in a calcium / magnesium humate storage tank; and is sent to a calcium / magnesium humate product storage tank for sale as needed, or is sent to a sulfite reduction reaction unit for the preparation of a high-purity humic acid product; when it is necessary to send it to a calcium / magnesium humate product storage tank, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank enters the first dryer for drying, and after drying, is sent to a calcium / magnesium humate product storage tank for temporary storage and sale;

[0020] Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank enters the sulfurous acid solution storage tank, and sulfur dioxide gas is fed into the sulfurous acid solution storage tank through the sulfur dioxide gas tank;

[0021] The following reactions occur in the sulfurous acid solution storage tank:

[0022] HA-Ca / Mg+H 2 SO 3 →HA+Ca / Mg SO 3 (precipitation)

[0023] Ca / Mg SO 3 (precipitation)+SO 2 (Excess) → Ca / Mg(HSO 3 ) 2 (Solution)

[0024] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0025] Step 6: the reactants in the sulfurous acid solution storage tank enter the second plate-frame filter press for filtration, the filter cake is the humic acid product, the humic acid product is washed and desalted by the water washing device in the high-purity humic acid processing unit, and then dried by the second dryer and sent to the high-purity humic acid product storage tank; the washing liquid in the water washing device is a calcium / magnesium bisulfite solution;

[0026] Step 7: The washing liquid after washing by the washing device and the filtrate produced by the second plate and frame filter press are temporarily stored in the calcium bisulfite / magnesium solution storage tank, and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank for reaction, and the reaction is as follows:

[0027] Ca / Mg(HSO 3 ) 2 + HCl → SO 2 (Gas)+Ca / Mg(Cl) 2

[0028] The sulfur dioxide gas produced by the above reaction enters the sulfur dioxide gas tank for reuse;

[0029] Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate and frame filter press in step 3 enter the filter for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to a high-concentration hard water storage tank for reuse.

[0030] According to the above scheme, a production device and production process for preparing high-purity humic acid using flocculation technology are prepared. By setting a high-concentration hard water flocculation reaction unit, high-concentration hard water can directly strip the humic acid flocculation from the system, avoiding the defects of using strong acid to adjust the pH value and the subsequent need for precision filters (or semi-permeable dialysis membranes) to filter. Furthermore, it can not only avoid the strong acid to adjust the pH value, resulting in strong acidity of the humic acid product or high water washing intensity and a lot of wastewater, but also avoid the characteristics of equipment corrosion and harm to operators caused by strong acids; it has the characteristics of convenient production, high efficiency, easy control of the production process and stable products. The present invention also uses the characteristics that sulfurous acid is stronger than humic acid, uses sulfurous acid when reducing humic acid, and adds excessive sulfur dioxide. The calcium / magnesium sulfite precipitate is further converted into soluble calcium / magnesium bisulfite. The pH of the sulfite-bisulfite system is only 3-5, so that only weakly acidic humic acid precipitate remains in the system. Sulfur dioxide is gaseous and easily soluble in water. After simple water washing, weakly acidic high-purity humic acid can be obtained, thereby achieving the purpose of conveniently extracting humic acid products, that is, it can be obtained by pressure filtration, water washing and drying, and has the characteristics of being easy to separate and purify; further, the calcium / magnesium bisulfite generated in the production process can be further used with dilute hydrochloric acid, and the sulfur dioxide can be reduced and recycled by using the principle of strong acid to weak acid, and the generated calcium / magnesium chloride is recycled into a high-concentration hard water storage tank for repeated use, with material balance, no waste gas, waste liquid, and waste residue are discharged, and it is green and environmentally friendly with low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention.

[0032] In the figure: 1. Raw material storage tank; 2. High-purity humic acid product storage tank; 3. Raw material reactor; 4. Alkali solution storage tank; 5. Desalted water pipeline; 6. Crude humate solution storage tank; 7. Horizontal screw centrifuge; 8. Refined humate solution storage tank; 9. Flocculation reaction tank; 10. High-concentration hard water storage tank; 11. First plate and frame filter press; 12. Humic acid calcium / magnesium temporary storage tank; 13. Sulfite solution storage tank; 14. Sulfur dioxide gas tank; 15. Second plate and frame filter press; 16. Filter; 17. First dryer; 18. Humic acid calcium / magnesium product storage tank; 19. Water washing device; 20. Second dryer; 21. Dilute hydrochloric acid solution storage tank; 22. Calcium / magnesium hydrogen sulfite solution storage tank. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] Reference Figure 1 As shown, the present invention is a production device for preparing high-purity humic acid by flocculation technology, comprising a raw material storage tank 1 and a high-purity humic acid product storage tank 2, wherein the raw material storage tank 1 is connected to a high-concentration hard water flocculation reaction unit through a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to a high-purity humic acid product storage tank 2 through a sulfite reduction reaction unit and a high-purity humic acid treatment unit in turn. The present invention abandons the traditional technical route, and uses a high-concentration hard water flocculation reaction unit to rapidly flocculate a humate solution with high-concentration calcium and magnesium ions to obtain a humic acid calcium and magnesium intermediate product; the above-mentioned humic acid calcium and magnesium intermediate product enters a sulfite reduction reaction unit for reduction reaction to obtain a calcium and magnesium sulfite precipitate, and uses excess sulfur dioxide to convert the calcium and magnesium sulfite precipitate into soluble calcium and magnesium bisulfite, and finally passes through high-purity humic acid. The above-mentioned technical route does not require pH adjustment, which greatly reduces the difficulty of operation; at the same time, it does not use strong acid to cause serious equipment corrosion and a short service life, and can also avoid the problem that acid mist affects the health of operators.

[0035] Furthermore, the humate refining unit comprises a raw material reactor 3, the inlet of the raw material reactor 3 is respectively connected to the raw material storage tank 1, the alkali solution storage tank 4 and the desalted water pipeline 5, the outlet of the raw material reactor 3 is connected to the crude humate solution storage tank 6, and the crude humate solution storage tank 6 is connected to the refined humate solution storage tank 8 through a horizontal screw centrifuge 7. The present invention specifically achieves the purpose of obtaining a refined humate solution by subjecting the raw material coal and the alkali solution to extraction reaction in the raw material reactor 3 and centrifugation treatment thereof through the horizontal screw centrifuge 7, thereby laying a foundation for the subsequent flocculation reaction.

[0036] Furthermore, the outlet of the refined humate solution storage tank 8 in the humate refining unit is connected to the middle inlet of the flocculation reaction tank 9, the top inlet of the flocculation reaction tank 9 is connected to the high-concentration hard water storage tank 10, the bottom outlet of the high-concentration hard water storage tank 10 is connected to the first plate-frame filter press 11, and the solid phase outlet of the first plate-frame filter press 11 is connected to the calcium / magnesium humate temporary storage tank 12. The above arrangement enables the refined humate solution and the high-concentration hard water to produce a flocculation reaction in the flocculation reaction tank 9, thereby obtaining the calcium-magnesium humate intermediate product without using concentrated acid and adjusting the pH value, thereby achieving the purification and separation of humic acid.

[0037] Furthermore, the outlet of the calcium / magnesium humate temporary storage tank 12 is connected to the sulfurous acid solution storage tank 13 in the sulfurous acid reduction reaction unit, the gas phase inlet of the sulfurous acid solution storage tank 13 is connected to the sulfur dioxide gas tank 14, and the outlet of the sulfurous acid solution storage tank 13 is connected to the second plate-frame filter press 15. The above arrangement enables the calcium / magnesium humate intermediate product to enter the sulfurous acid reduction reaction unit for reduction reaction to obtain calcium / magnesium sulfite precipitation, and utilizes excess sulfur dioxide to convert the calcium / magnesium sulfite precipitation into soluble calcium / magnesium hydrogen sulfite, and finally passes through high-purity humic acid; the above reaction process is carried out in the sulfurous acid solution storage tank 13, and the sulfurous acid solution is not a strong acid, which can achieve the characteristics of no acid mist generation and environmental protection without environmental pollution.

[0038] Furthermore, the liquid phase outlet of the first plate-frame filter press 11 is connected to the high-concentration hard water storage tank 10 through the filter 16. The liquid phase filtered by the first plate-frame filter press 11 can be recovered to achieve the characteristic of repeated reuse.

[0039] Furthermore, the outlet of the calcium / magnesium humate temporary storage tank 12 is also connected to the calcium / magnesium humate product storage tank 18 through the first dryer 17. Calcium / magnesium humate has a good improvement effect on acidic soil. Based on this, the present invention can flexibly adjust the product according to market conditions.

[0040] Further, the solid phase outlet of the second plate-frame filter press 15 is connected to the high-purity humic acid product storage tank 2 through a water washing device 19 and a second dryer 20. The water washing device 19 described in the present invention includes a desalted water tank, a belt conveyor and a fully automatic desalted washing machine, which can be directly purchased on the market, so the structure is not repeated. After water washing and desalination, the product is dried by the second dryer 20, and after drying, it enters the high-purity humic acid product storage tank 2 for sale. Further, the liquid phase outlet of the second plate-frame filter press 15 and the liquid phase outlet of the water washing device 19 are respectively connected to the calcium bisulfite / magnesium solution storage tank 22, the outlet of the calcium bisulfite / magnesium solution storage tank 22 is connected to the dilute hydrochloric acid solution storage tank 21, the gas phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the inlet of the sulfur dioxide gas tank 14, and the liquid phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the high-concentration hard water storage tank 10 through the filter 16. The present invention is also provided with a liquid phase recovery unit, through which sulfur dioxide gas and liquid phase can be recovered, which not only has the characteristics of reducing production costs, but also can achieve no waste gas and waste acid liquid discharge, meets environmental protection requirements and reduces production risks.

[0041] A production process for preparing high-purity humic acid by using flocculation technology, the production process is as follows: raw coal in a raw material storage tank 1 is fed into a humate refining unit, humic acid in the raw coal is extracted by alkaline solution to obtain a humate solution, the property of humic acid complexing divalent metal ions to form a precipitate is utilized, a high-concentration hard water flocculation reaction unit is used to combine high-concentration calcium and magnesium ions with humate to flocculate to obtain a humate calcium-magnesium intermediate product; the humate calcium-magnesium intermediate product is fed into a sulfite reduction reaction unit for reduction reaction to obtain a calcium-magnesium sulfite precipitate, and excess sulfur dioxide is used to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium hydrogen sulfite, and finally a high-purity humic acid product is obtained by water washing and drying in a high-purity humic acid treatment unit, and the high-purity humic acid product enters a high-purity humic acid product storage tank 2.

[0042] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising the following steps:

[0043] Step 1: The raw coal in the raw material storage tank 1 enters the raw material reactor 3, and the alkali solution storage tank 4 and the desalted water pipeline 5 add alkali solution and desalted water into the raw material reactor 3 respectively, so that the mass ratio of the raw material coal, alkali and water is 8-10:10:20, and the raw material reactor 3 is stirred and heated to 120-160° C. and reacted for 2 hours;

[0044] Step 2: sending the reaction liquid after the reaction in the raw material reactor 3 to the crude humate solution storage tank 6 for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank 6 to a horizontal screw centrifuge 7 for centrifugation to remove insoluble matter, and sending the centrifuged liquid to the refined humate solution storage tank 8 for temporary storage;

[0045] Step 3: The centrifugal liquid in the refined humate solution storage tank 8 enters the flocculation reaction tank 9, and at the same time, the high-concentration hard water with a hardness of 150 to 200 in the high-concentration hard water storage tank 10 is sent to the flocculation reaction tank 9. The reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate-frame filter press 11 for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 20 to 30:1;

[0046] Step 4: The filter cake after filtration by the first plate-frame filter press 11 is a flocculated calcium / magnesium humate intermediate product, and the calcium / magnesium humate is sent to the calcium / magnesium humate temporary storage tank 12 for temporary storage; and sent to the calcium / magnesium humate product storage tank 18 for sale as needed, or sent to the sulfite reduction reaction unit for preparing a high-purity humic acid product; when it is necessary to send it to the calcium / magnesium humate product storage tank 18, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the first dryer 17 for drying, and after drying, it is sent to the calcium / magnesium humate product storage tank 18 for temporary storage and sale;

[0047] Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the sulfurous acid solution storage tank 13, and sulfur dioxide gas is fed into the sulfurous acid solution storage tank 13 through the sulfur dioxide gas tank 14;

[0048] The following reaction occurs in the sulfurous acid solution storage tank 13:

[0049] HA-Ca / Mg+H 2 SO 3 →HA+Ca / Mg SO 3 (precipitation)

[0050] Ca / Mg SO 3 (precipitation)+SO 2 (Excess) → Ca / Mg(HSO 3 ) 2 (Solution)

[0051] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0052] Step 6: The reactants in the sulfurous acid solution storage tank 13 enter the second plate-frame filter press 15 for filtration, and the filter cake is a humic acid product. The humic acid product is washed and desalted by the water washing device 19 in the high-purity humic acid processing unit, and then dried by the second dryer 20 and sent to the high-purity humic acid product storage tank 2; the washing liquid in the water washing device 19 is a calcium / magnesium bisulfite solution;

[0053] Step 7: The washing liquid after washing by the washing device 19 and the filtrate produced by the second plate and frame filter press 15 are temporarily stored in the calcium bisulfite / magnesium solution storage tank 22, and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank 21 for reaction, and the reaction is as follows:

[0054] Ca / Mg(HSO 3 ) 2 + HCl → SO 2 (Gas)+Ca / Mg(Cl) 2

[0055] The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank 14 for reuse;

[0056] Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate-frame filter press 11 in step 3 enter the filter 16 for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank 10 for reuse.

[0057] The present invention uses an alkali-dissolved, flocculated and then reduced method to extract humic acid in the raw coal by alkali solution to obtain a humate solution, and then no longer uses an acid solution to precipitate the humic acid. Instead, the humic acid is treated with high-concentration calcium and magnesium ions to quickly flocculate the humate solution to obtain a humic acid calcium-magnesium intermediate product by utilizing the property of humic acid complexing divalent metal ions to form a precipitate, and then the humic acid is replaced by sulfurous acid with a stronger acidity, and a calcium-magnesium sulfite precipitate is obtained at the same time. Excessive sulfur dioxide is introduced to convert the calcium-sulfite / magnesium precipitate into a soluble calcium-hydrogen sulfite / magnesium precipitate, which is then washed and removed to obtain a high-purity humic acid product, and then used Dilute hydrochloric acid reacts with calcium / magnesium hydrogen sulfite to displace sulfur dioxide for recycling, and the generated calcium chloride / magnesium solution is transferred to a high-concentration hard water storage tank for recycling after treatment; the above process is fully closed, no waste gas and waste acid liquid are discharged, the sulfurous acid used does not corrode equipment, and the price is also cheap, the production cost is greatly reduced, and it can meet environmental protection requirements and reduce production risks; in addition, the hard water used is non-toxic and very easy to obtain, the price is cheap, the production cost is greatly reduced, and no acid mist is generated in the closed pipeline, the whole process is environmentally friendly and has no environmental pollution, and the obtained humic acid product has undergone multi-stage separation, has few impurities and high purity.

[0058] In order to explain the present invention in more detail, the present invention is further described in conjunction with embodiments. The specific embodiments are as follows:

[0059] Example 1

[0060] A production device for preparing high-purity humic acid using flocculation technology comprises a raw material storage tank 1 and a high-purity humic acid product storage tank 2. The raw material storage tank 1 is connected to a high-concentration hard water flocculation reaction unit via a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank 2 via a sulfite reduction reaction unit and a high-purity humic acid treatment unit.

[0061] A production process for preparing high-purity humic acid by using flocculation technology, the production process is as follows: raw coal in a raw material storage tank 1 is fed into a humate refining unit, humic acid in the raw coal is extracted by alkaline solution to obtain a humate solution, the property of humic acid complexing divalent metal ions to form a precipitate is utilized, a high-concentration hard water flocculation reaction unit is used to combine high-concentration calcium and magnesium ions with humate to flocculate to obtain a humate calcium-magnesium intermediate product; the humate calcium-magnesium intermediate product is fed into a sulfite reduction reaction unit for reduction reaction to obtain a calcium-magnesium sulfite precipitate, and excess sulfur dioxide is used to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium hydrogen sulfite, and finally a high-purity humic acid product is obtained by water washing and drying in a high-purity humic acid treatment unit, and the high-purity humic acid product enters a high-purity humic acid product storage tank 2.

[0062] Example 2

[0063] A production device for preparing high-purity humic acid using flocculation technology, comprising a raw material storage tank 1 and a high-purity humic acid product storage tank 2, wherein the raw material storage tank 1 is connected to a high-concentration hard water flocculation reaction unit through a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank 2 through a sulfite reduction reaction unit and a high-purity humic acid treatment unit in turn. The humate refining unit comprises a raw material reactor 3, the inlet of which is respectively connected to the raw material storage tank 1, an alkali solution storage tank 4 and a desalted water pipeline 5, the outlet of which is connected to a crude humate solution storage tank 6, and the crude humate solution storage tank 6 is connected to a refined humate solution storage tank 8 through a horizontal screw centrifuge 7. The outlet of the refined humate solution storage tank 8 in the humate refining unit is connected to the middle inlet of the flocculation reaction tank 9, the top inlet of the flocculation reaction tank 9 is connected to the high-concentration hard water storage tank 10, the bottom outlet of the high-concentration hard water storage tank 10 is connected to the first plate-frame filter press 11, and the solid phase outlet of the first plate-frame filter press 11 is connected to the calcium / magnesium humate temporary storage tank 12. The outlet of the calcium / magnesium humate temporary storage tank 12 is connected to the sulfurous acid solution storage tank 13 in the sulfurous acid reduction reaction unit, the gas phase inlet of the sulfurous acid solution storage tank 13 is connected to the sulfur dioxide gas tank 14, and the outlet of the sulfurous acid solution storage tank 13 is connected to the second plate-frame filter press 15. The liquid phase outlet of the first plate-frame filter press 11 is connected to the high-concentration hard water storage tank 10 through the filter 16. The outlet of the calcium / magnesium humate temporary storage tank 12 is also connected to the calcium / magnesium humate product storage tank 18 through the first dryer 17. The solid phase outlet of the second plate-frame filter press 15 is connected to the high-purity humic acid product storage tank 2 through the water washing device 19 and the second dryer 20. The liquid phase outlet of the second plate-frame filter press 15 and the liquid phase outlet of the water washing device 19 are respectively connected to the calcium / magnesium bisulfite solution storage tank 22, the outlet of the calcium / magnesium bisulfite solution storage tank 22 is connected to the dilute hydrochloric acid solution storage tank 21, the gas phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the inlet of the sulfur dioxide gas tank 14, and the liquid phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the high-concentration hard water storage tank 10 through the filter 16.

[0064] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising the following steps:

[0065] Step 1: The raw coal in the raw material storage tank 1 enters the raw material reactor 3, and the alkali solution storage tank 4 and the desalted water pipeline 5 add alkali solution and desalted water into the raw material reactor 3 respectively, so that the mass ratio of the raw material coal, alkali and water is 8:10:20, and the raw material reactor 3 is stirred and heated, and the temperature is raised to 120°C and then reacted for 2 hours;

[0066] Step 2: sending the reaction liquid after the reaction in the raw material reactor 3 to the crude humate solution storage tank 6 for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank 6 to a horizontal screw centrifuge 7 for centrifugation to remove insoluble matter, and sending the centrifuged liquid to the refined humate solution storage tank 8 for temporary storage;

[0067] Step 3: The centrifugal liquid in the refined humate solution storage tank 8 enters the flocculation reaction tank 9, and at the same time, the high-concentration hard water with a hardness of 150 in the high-concentration hard water storage tank 10 is sent to the flocculation reaction tank 9. The reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate-frame filter press 11 for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 20:1;

[0068] Step 4: The filter cake after filtration by the first plate and frame filter press 11 is a calcium / magnesium humate intermediate product, and the calcium / magnesium humate is sent to the calcium / magnesium humate temporary storage tank 12 for temporary storage; and sent to the calcium / magnesium humate product storage tank 18 for sale as needed, or sent to the sulfite reduction reaction unit for preparing a high-purity humic acid product; when it is necessary to send it to the calcium / magnesium humate product storage tank 18, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the first dryer 17 for drying, and after drying, it is sent to the calcium / magnesium humate product storage tank 18 for temporary storage and sale;

[0069] Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the sulfurous acid solution storage tank 13, and sulfur dioxide gas is fed into the sulfurous acid solution storage tank 13 through the sulfur dioxide gas tank 14;

[0070] The following reaction occurs in the sulfurous acid solution storage tank 13:

[0071] HA-Ca / Mg+H 2 SO 3 →HA+Ca / Mg SO 3 (precipitation)

[0072] Ca / Mg SO 3 (precipitation)+SO 2 (Excess) → Ca / Mg(HSO 3 ) 2 (Solution)

[0073] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0074] Step 6: The reactants in the sulfurous acid solution storage tank 13 enter the second plate-frame filter press 15 for filtration, and the filter cake is a humic acid product. The humic acid product is washed and desalted by the water washing device 19 in the high-purity humic acid processing unit, and then dried by the second dryer 20 and sent to the high-purity humic acid product storage tank 2; the washing liquid in the water washing device 19 is a calcium / magnesium bisulfite solution;

[0075] Step 7: The washing liquid after washing by the washing device 19 and the filtrate produced by the second plate and frame filter press 15 are temporarily stored in the calcium bisulfite / magnesium solution storage tank 22, and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank 21 for reaction, and the reaction is as follows:

[0076] Ca / Mg(HSO 3 ) 2 + HCl → SO 2 (Gas)+Ca / Mg(Cl) 2

[0077] The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank 14 for reuse;

[0078] Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate-frame filter press 11 in step 3 enter the filter 16 for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank 10 for reuse.

[0079] Example 3

[0080] A production device for preparing high-purity humic acid using flocculation technology, comprising a raw material storage tank 1 and a high-purity humic acid product storage tank 2, wherein the raw material storage tank 1 is connected to a high-concentration hard water flocculation reaction unit through a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank 2 through a sulfite reduction reaction unit and a high-purity humic acid treatment unit in turn. The humate refining unit comprises a raw material reactor 3, the inlet of which is respectively connected to the raw material storage tank 1, an alkali solution storage tank 4 and a desalted water pipeline 5, the outlet of which is connected to a crude humate solution storage tank 6, and the crude humate solution storage tank 6 is connected to a refined humate solution storage tank 8 through a horizontal screw centrifuge 7. The outlet of the refined humate solution storage tank 8 in the humate refining unit is connected to the middle inlet of the flocculation reaction tank 9, the top inlet of the flocculation reaction tank 9 is connected to the high-concentration hard water storage tank 10, the bottom outlet of the high-concentration hard water storage tank 10 is connected to the first plate-frame filter press 11, and the solid phase outlet of the first plate-frame filter press 11 is connected to the calcium / magnesium humate temporary storage tank 12. The outlet of the calcium / magnesium humate temporary storage tank 12 is connected to the sulfurous acid solution storage tank 13 in the sulfurous acid reduction reaction unit, the gas phase inlet of the sulfurous acid solution storage tank 13 is connected to the sulfur dioxide gas tank 14, and the outlet of the sulfurous acid solution storage tank 13 is connected to the second plate-frame filter press 15. The liquid phase outlet of the first plate-frame filter press 11 is connected to the high-concentration hard water storage tank 10 through the filter 16. The outlet of the calcium / magnesium humate temporary storage tank 12 is also connected to the calcium / magnesium humate product storage tank 18 through the first dryer 17. The solid phase outlet of the second plate-frame filter press 15 is connected to the high-purity humic acid product storage tank 2 through the water washing device 19 and the second dryer 20. The liquid phase outlet of the second plate-frame filter press 15 and the liquid phase outlet of the water washing device 19 are respectively connected to the calcium / magnesium bisulfite solution storage tank 22, the outlet of the calcium / magnesium bisulfite solution storage tank 22 is connected to the dilute hydrochloric acid solution storage tank 21, the gas phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the inlet of the sulfur dioxide gas tank 14, and the liquid phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the high-concentration hard water storage tank 10 through the filter 16.

[0081] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising the following steps:

[0082] Step 1: The raw coal in the raw material storage tank 1 enters the raw material reactor 3, and the alkali solution storage tank 4 and the desalted water pipeline 5 add alkali solution and desalted water into the raw material reactor 3 respectively, so that the mass ratio of the raw material coal, alkali and water is 10:10:20, and the raw material reactor 3 is stirred and heated to 160°C and reacted for 2 hours;

[0083] Step 2: sending the reaction liquid after the reaction in the raw material reactor 3 to the crude humate solution storage tank 6 for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank 6 to a horizontal screw centrifuge 7 for centrifugation to remove insoluble matter, and sending the centrifuged liquid to the refined humate solution storage tank 8 for temporary storage;

[0084] Step 3: The centrifugal liquid in the refined humate solution storage tank 8 enters the flocculation reaction tank 9, and at the same time, the high-concentration hard water with a degree of hardness of 200 in the high-concentration hard water storage tank 10 is sent to the flocculation reaction tank 9. The reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate-frame filter press 11 for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 30:1;

[0085] Step 4: The filter cake after filtration by the first plate and frame filter press 11 is a calcium / magnesium humate intermediate product, and the calcium / magnesium humate is sent to the calcium / magnesium humate temporary storage tank 12 for temporary storage; and sent to the calcium / magnesium humate product storage tank 18 for sale as needed, or sent to the sulfite reduction reaction unit for preparing a high-purity humic acid product; when it is necessary to send it to the calcium / magnesium humate product storage tank 18, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the first dryer 17 for drying, and after drying, it is sent to the calcium / magnesium humate product storage tank 18 for temporary storage and sale;

[0086] Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the sulfurous acid solution storage tank 13, and sulfur dioxide gas is fed into the sulfurous acid solution storage tank 13 through the sulfur dioxide gas tank 14;

[0087] The following reaction occurs in the sulfurous acid solution storage tank 13:

[0088] HA-Ca / Mg+H 2 SO 3 →HA+Ca / Mg SO 3 (precipitation)

[0089] Ca / Mg SO 3 (precipitation)+SO 2 (Excess) → Ca / Mg(HSO 3 ) 2 (Solution)

[0090] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0091] Step 6: The reactants in the sulfurous acid solution storage tank 13 enter the second plate-frame filter press 15 for filtration, and the filter cake is a humic acid product. The humic acid product is washed and desalted by the water washing device 19 in the high-purity humic acid processing unit, and then dried by the second dryer 20 and sent to the high-purity humic acid product storage tank 2; the washing liquid in the water washing device 19 is a calcium / magnesium bisulfite solution;

[0092] Step 7: The washing liquid after washing by the washing device 19 and the filtrate produced by the second plate and frame filter press 15 are temporarily stored in the calcium bisulfite / magnesium solution storage tank 22, and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank 21 for reaction, and the reaction is as follows:

[0093] Ca / Mg(HSO 3 ) 2 + HCl → SO 2 (Gas)+Ca / Mg(Cl) 2

[0094] The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank 14 for reuse;

[0095] Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate-frame filter press 11 in step 3 enter the filter 16 for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank 10 for reuse.

[0096] Example 4

[0097] A production device for preparing high-purity humic acid using flocculation technology, comprising a raw material storage tank 1 and a high-purity humic acid product storage tank 2, wherein the raw material storage tank 1 is connected to a high-concentration hard water flocculation reaction unit through a humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank 2 through a sulfite reduction reaction unit and a high-purity humic acid treatment unit in turn. The humate refining unit comprises a raw material reactor 3, the inlet of which is respectively connected to the raw material storage tank 1, an alkali solution storage tank 4 and a desalted water pipeline 5, the outlet of which is connected to a crude humate solution storage tank 6, and the crude humate solution storage tank 6 is connected to a refined humate solution storage tank 8 through a horizontal screw centrifuge 7. The outlet of the refined humate solution storage tank 8 in the humate refining unit is connected to the middle inlet of the flocculation reaction tank 9, the top inlet of the flocculation reaction tank 9 is connected to the high-concentration hard water storage tank 10, the bottom outlet of the high-concentration hard water storage tank 10 is connected to the first plate-frame filter press 11, and the solid phase outlet of the first plate-frame filter press 11 is connected to the calcium / magnesium humate temporary storage tank 12. The outlet of the calcium / magnesium humate temporary storage tank 12 is connected to the sulfurous acid solution storage tank 13 in the sulfurous acid reduction reaction unit, the gas phase inlet of the sulfurous acid solution storage tank 13 is connected to the sulfur dioxide gas tank 14, and the outlet of the sulfurous acid solution storage tank 13 is connected to the second plate-frame filter press 15. The liquid phase outlet of the first plate-frame filter press 11 is connected to the high-concentration hard water storage tank 10 through the filter 16. The outlet of the calcium / magnesium humate temporary storage tank 12 is also connected to the calcium / magnesium humate product storage tank 18 through the first dryer 17. The solid phase outlet of the second plate-frame filter press 15 is connected to the high-purity humic acid product storage tank 2 through the water washing device 19 and the second dryer 20. The liquid phase outlet of the second plate-frame filter press 15 and the liquid phase outlet of the water washing device 19 are respectively connected to the calcium / magnesium bisulfite solution storage tank 22, the outlet of the calcium / magnesium bisulfite solution storage tank 22 is connected to the dilute hydrochloric acid solution storage tank 21, the gas phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the inlet of the sulfur dioxide gas tank 14, and the liquid phase outlet of the dilute hydrochloric acid solution storage tank 21 is connected to the high-concentration hard water storage tank 10 through the filter 16.

[0098] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising the following steps:

[0099] Step 1: The raw coal in the raw material storage tank 1 enters the raw material reactor 3, and the alkali solution storage tank 4 and the desalted water pipeline 5 add alkali solution and desalted water into the raw material reactor 3 respectively, so that the mass ratio of the raw material coal, alkali and water is 9:10:20, and the raw material reactor 3 is stirred and heated to 140°C and reacted for 2 hours;

[0100] Step 2: sending the reaction liquid after the reaction in the raw material reactor 3 to the crude humate solution storage tank 6 for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank 6 to a horizontal screw centrifuge 7 for centrifugation to remove insoluble matter, and sending the centrifuged liquid to the refined humate solution storage tank 8 for temporary storage;

[0101] Step 3: The centrifugal liquid in the refined humate solution storage tank 8 enters the flocculation reaction tank 9, and at the same time, the high-concentration hard water with a hardness of 180 in the high-concentration hard water storage tank 10 is sent to the flocculation reaction tank 9. The reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate-frame filter press 11 for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 25:1;

[0102] Step 4: The filter cake after filtration by the first plate and frame filter press 11 is a calcium / magnesium humate intermediate product, and the calcium / magnesium humate is sent to the calcium / magnesium humate temporary storage tank 12 for temporary storage; and sent to the calcium / magnesium humate product storage tank 18 for sale as needed, or sent to the sulfite reduction reaction unit for preparing a high-purity humic acid product; when it is necessary to send it to the calcium / magnesium humate product storage tank 18, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the first dryer 17 for drying, and after drying, it is sent to the calcium / magnesium humate product storage tank 18 for temporary storage and sale;

[0103] Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank 12 enters the sulfurous acid solution storage tank 13, and sulfur dioxide gas is fed into the sulfurous acid solution storage tank 13 through the sulfur dioxide gas tank 14;

[0104] The following reaction occurs in the sulfurous acid solution storage tank 13:

[0105] HA-Ca / Mg+H 2 SO 3 →HA+Ca / Mg SO 3 (precipitation)

[0106] Ca / Mg SO 3 (precipitation)+SO 2 (Excess) → Ca / Mg(HSO 3 ) 2 (Solution)

[0107] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0108] Step 6: The reactants in the sulfurous acid solution storage tank 13 enter the second plate-frame filter press 15 for filtration, and the filter cake is a humic acid product. The humic acid product is washed and desalted by the water washing device 19 in the high-purity humic acid processing unit, and then dried by the second dryer 20 and sent to the high-purity humic acid product storage tank 2; the washing liquid in the water washing device 19 is a calcium / magnesium bisulfite solution;

[0109] Step 7: The washing liquid after washing by the washing device 19 and the filtrate produced by the second plate and frame filter press 15 are temporarily stored in the calcium bisulfite / magnesium solution storage tank 22, and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank 21 for reaction, and the reaction is as follows:

[0110] Ca / Mg(HSO 3 ) 2 + HCl → SO 2 (Gas)+Ca / Mg(Cl) 2

[0111] The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank 14 for reuse;

[0112] Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate-frame filter press 11 in step 3 enter the filter 16 for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank 10 for reuse.

[0113] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A production device for preparing high-purity humic acid using flocculation technology, comprising a raw material storage tank (1) and a high-purity humic acid product storage tank (2), characterized in that: The raw material storage tank (1) is connected to the high-concentration hard water flocculation reaction unit via the humate solution refining unit, and the high-concentration hard water flocculation reaction unit is connected to the high-purity humic acid product storage tank (2) via the sulfite reduction reaction unit and the high-purity humic acid treatment unit in turn.

2. The production device for preparing high-purity humic acid using flocculation technology according to claim 1, characterized in that: The humate refining unit comprises a raw material reactor (3), the inlet of the raw material reactor (3) is respectively connected to a raw material storage tank (1), an alkali solution storage tank (4) and a desalted water pipeline (5), the outlet of the raw material reactor (3) is connected to a crude humate solution storage tank (6), and the crude humate solution storage tank (6) is connected to a refined humate solution storage tank (8) via a horizontal screw centrifuge (7).

3. The production device for preparing high-purity humic acid using flocculation technology according to claim 2, characterized in that: The outlet of the refined humate solution storage tank (8) in the humate refining unit is connected to the middle inlet of the flocculation reaction tank (9), the top inlet of the flocculation reaction tank (9) is connected to the high-concentration hard water storage tank (10), the bottom outlet of the high-concentration hard water storage tank (10) is connected to the first plate-frame filter press (11), and the solid phase outlet of the first plate-frame filter press (11) is connected to the calcium / magnesium humate temporary storage tank (12).

4. The production device for preparing high-purity humic acid using flocculation technology according to claim 3, characterized in that: The outlet of the calcium / magnesium humate temporary storage tank (12) is connected to the sulfurous acid solution storage tank (13) in the sulfurous acid reduction reaction unit, the gas phase inlet of the sulfurous acid solution storage tank (13) is connected to the sulfur dioxide gas tank (14), and the outlet of the sulfurous acid solution storage tank (13) is connected to the second plate and frame filter press (15).

5. The production device for preparing high-purity humic acid using flocculation technology according to claim 3, characterized in that: The liquid phase outlet of the first plate-and-frame filter press (11) is connected to the high-concentration hard water storage tank (10) via a filter (16).

6. The production device for preparing high-purity humic acid using flocculation technology according to claim 3, characterized in that: The outlet of the calcium / magnesium humate temporary storage tank (12) is also connected to the calcium / magnesium humate product storage tank (18) via a first dryer (17).

7. The production device for preparing high-purity humic acid using flocculation technology according to claim 4, characterized in that: The solid phase outlet of the second plate-and-frame filter press (15) is connected to the high-purity humic acid product storage tank (2) via a water washing device (19) and a second dryer (20).

8. The production device for preparing high-purity humic acid using flocculation technology according to claim 7, characterized in that: The liquid phase outlet of the second plate-and-frame filter press (15) and the liquid phase outlet of the water washing device (19) are respectively connected to a calcium / magnesium bisulfite solution storage tank (22), the outlet of the calcium / magnesium bisulfite solution storage tank (22) is connected to a dilute hydrochloric acid solution storage tank (21), the gas phase outlet of the dilute hydrochloric acid solution storage tank (21) is connected to an inlet of a sulfur dioxide gas tank (14), and the liquid phase outlet of the dilute hydrochloric acid solution storage tank (21) is connected to a high-concentration hard water storage tank (10) via a filter (16).

9. A production process for preparing high-purity humic acid using flocculation technology, characterized in that: The production process comprises the following steps: the raw coal in the raw material storage tank (1) is fed into a humate refining unit, humic acid in the raw coal is extracted by alkaline solution to obtain a humate solution, the property of humic acid complexing divalent metal ions to form a precipitate is utilized, a high-concentration hard water flocculation reaction unit is used to combine high-concentration calcium and magnesium ions with humate to flocculate to obtain a humate calcium and magnesium intermediate product; the humate calcium and magnesium intermediate product is fed into a sulfite reduction reaction unit to undergo a reduction reaction to obtain a calcium and magnesium sulfite precipitate, and excess sulfur dioxide is used to convert the calcium and magnesium sulfite precipitate into soluble calcium and magnesium hydrogen sulfite, and finally a high-purity humic acid product is obtained by water washing and drying in a high-purity humic acid treatment unit, and the high-purity humic acid product is fed into a high-purity humic acid product storage tank (2).

10. The production process for preparing high-purity humic acid using flocculation technology according to claim 9, characterized in that: The production process includes the following steps: Step 1: The raw coal in the raw material storage tank (1) enters the raw material reaction kettle (3), and the alkali solution storage tank (4) and the desalted water pipeline (5) respectively add alkali solution and desalted water into the raw material reaction kettle (3) to make the mass ratio of the raw material coal, alkali and water be 8 to 10:10:20, and the raw material reaction kettle (3) is stirred and heated to 120 to 160° C. and reacted for 2 hours; Step 2: sending the reaction liquid after the reaction in the raw material reactor (3) to a crude humate solution storage tank (6) for temporary storage, sending the crude humate solution temporarily stored in the crude humate solution storage tank (6) to a horizontal screw centrifuge (7) for centrifugation to remove insoluble matter, and sending the centrifuged liquid to a refined humate solution storage tank (8) for temporary storage; Step 3: the centrifugal liquid in the refined humate solution storage tank (8) enters the flocculation reaction tank (9), and at the same time, the high-concentration hard water with a hardness of 150 to 200 in the high-concentration hard water storage tank (10) is sent to the flocculation reaction tank (9), and the reaction liquid of the above two after stirring and reacting for 3 hours is sent to the first plate and frame filter press (11) for pressure filtration; the mass ratio of the high-concentration hard water to the centrifugal liquid is 20 to 30:1; Step 4: The filter cake after filtration by the first plate and frame filter press (11) is a calcium / magnesium humate intermediate product, and the calcium / magnesium humate is sent to the calcium / magnesium humate temporary storage tank (12) for temporary storage; and sent to the calcium / magnesium humate product storage tank (18) for external sale as needed, or sent to the sulfite reduction reaction unit for preparing a high-purity humic acid product; when it is necessary to send it to the calcium / magnesium humate product storage tank (18), the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank (12) enters the first dryer (17) for drying, and after drying, it is sent to the calcium / magnesium humate product storage tank (18) for temporary storage for external sale; Step 5: When a high-purity humic acid product needs to be prepared, the calcium / magnesium humate in the calcium / magnesium humate temporary storage tank (12) enters the sulfurous acid solution storage tank (13), and sulfur dioxide gas is fed into the sulfurous acid solution storage tank (13) through the sulfur dioxide gas tank (14); The following reaction occurs in the sulfurous acid solution storage tank (13): HA-Ca / Mg+H2SO3→HA+Ca / Mg SO3(precipitation) Ca / Mg SO3(precipitate)+SO2(excess)→Ca / Mg(HSO3)2(solution) The insoluble humic acid obtained by the above reaction is separated by precipitation; Step 6: the reactants in the sulfurous acid solution storage tank (13) enter the second plate-frame filter press (15) for filter pressing, and the filter cake is the humic acid product. The humic acid product is washed and desalted by the water washing device (19) in the high-purity humic acid processing unit, and then dried by the second dryer (20) and then sent to the high-purity humic acid product storage tank (2); the washing liquid in the water washing device (19) is a calcium / magnesium bisulfite solution; Step 7: The washing liquid after washing by the washing device (19) and the filtrate produced by the second plate and frame filter press (15) are temporarily stored in the calcium bisulfite / magnesium solution storage tank (22), and the temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank (21) for reaction, and the reaction is as follows: Ca / Mg(HSO3)2+HCl→SO2(gas)+Ca / Mg(Cl)2 The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank (14) for reuse; Step 8: The calcium chloride / magnesium solution produced in step 7 and the filtrate produced by the first plate and frame filter press (11) in step 3 enter the filter (16) for filtration and impurity removal, and the liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank (10) for reuse.

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