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

Abstract

The utility model relates to a production device 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 utility model relates to the technical field of high-purity humic acid production, in particular to a production device 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, China Patent Publication No.: CN101033241B, the patent name is: A method for preparing high-purity humic acid, which discloses the preparation of high-purity humic acid by the following steps, namely: (1) extracting humic acid from coal with an alkali solution, adding a coagulant, centrifuging and removing the residue to obtain humic acid sodium salt; (2) adding a complexing agent under slightly acidic conditions to remove high-valent cations; (3) after acidification, removing inorganic salts and soluble complex ions in the colloidal system by electrodialysis; (4) obtaining humic acid powder with a purity of ≥95% after drying. In short, in traditional technology, the preparation of high-purity humic acid is carried out by the alkali dissolution and acid precipitation method. First, the raw coal is reacted with caustic soda / potassium solution and then centrifuged to obtain humic sodium / potassium solution. Then, a strong acid such as hydrochloric acid is used to adjust the pH to 1-3. The humic acid insoluble in acid will precipitate, and then the high-purity humic acid is obtained by separation, water washing or electrodialysis, and drying. The above method has the following drawbacks: 1. Since high-purity humic acid is prepared under strong acid conditions, the product is highly acidic, generally with a pH value of 1 to 3; this is not only harmful to crops, but also easily accelerates soil acidification and salinization; 2. The entire preparation process is relatively cumbersome and complicated, especially the amount of acid used in acid precipitation, which is directly related to the amount of alkali used. The system pH needs to be monitored at all times, is difficult to control, and is very prone to fluctuations, making it extremely difficult to stabilize product quality; 3. The acid used in the acid precipitation process is mostly hydrochloric acid, and the acid mist generated during the neutralization process is highly corrosive, extremely corrosive to metal equipment, and extremely harmful to operators. It is extremely difficult to handle, and the residual acid is difficult to handle, resulting in severe environmental pollution and high production risks. Utility Model Content

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

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

[0005] A production device for preparing high-purity humic acid using flocculation technology includes 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 treatment unit.

[0006] The beneficial effects of the present invention are as follows: the present invention abandons the prior art method of using acid to precipitate humic acid, and the method of utilizing the colloid and complex divalent metal ion precipitation characteristics of humic acid, and adopts flocculation technology to use high-concentration hard water to directly separate 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 bisulfite, so that only humic acid precipitate remains in the system, and a high-purity humic acid product can be obtained after water washing and purification; the above process does not require pH control, thereby reducing the difficulty of operation; at the same time, the sulfurous acid used is a weak acid, and 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, thereby achieving the purpose of making the product weakly acidic, and further, it can avoid the characteristic of harm to equipment and operators.

[0007] Preferably, the humate refining unit includes a raw material reactor, the inlet of which is respectively connected to the raw material storage tank, the alkali solution storage tank and the desalted water pipeline, the outlet of the raw material reactor is connected to the crude humate solution storage tank, and the crude humate solution storage tank is connected to the refined humate solution storage tank through 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 the high-purity humic acid product storage tank through 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] According to the above scheme, a production device for preparing high-purity humic acid using flocculation technology is made. 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 characteristics of strong acid adjustment of the pH value, which leads to 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 acid; it has the characteristics of convenient production, high efficiency, easy control of the production process and stable products. The utility model also takes advantage of the fact that sulfurous acid is stronger than humic acid, uses sulfurous acid when reducing humic acid, and adds excess sulfur dioxide to The calcium / magnesium sulfite precipitate is converted into soluble calcium / magnesium bisulfite in one step. 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 in a gaseous state and easily soluble in water. After a simple water washing, weakly acidic high-purity humic acid can be obtained, thereby achieving the purpose of conveniently extracting the humic acid product. That is, it can be obtained by pressure filtration, water washing and drying, and has the characteristics of being easy to separate and purify. Furthermore, the calcium / magnesium bisulfite generated in the production process can be further reduced and recycled using dilute hydrochloric acid by utilizing 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. The material balance is achieved, and no waste gas, waste liquid or waste residue is discharged. The process is environmentally friendly and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the present utility model.

[0016] Figure 1: 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. Decanter 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 bisulfite solution storage tank. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0018] Reference Figure 1 As shown, the present invention is a production device for producing high-purity humic acid using flocculation technology, comprising 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, which is in turn 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. The present invention abandons the traditional technical route. By using a high-concentration hard water flocculation reaction unit, high-concentration calcium and magnesium ions are rapidly flocculated on the humate solution to produce a calcium-magnesium humate intermediate product. This calcium-magnesium humate intermediate product is then introduced into a sulfite reduction reaction unit for a reduction reaction to produce a calcium-magnesium sulfite precipitate. Excess sulfur dioxide is used to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium bisulfite, ultimately producing high-purity humic acid. This technical route does not require pH adjustment, significantly reducing operational complexity. Furthermore, the present invention avoids the drawbacks of using strong acids, which can cause severe equipment corrosion and shorten service life, and also avoids the problem of acid mist affecting the health of operators.

[0019] Furthermore, the humate refining unit includes a raw material reactor 3, the inlet of which is 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, which is connected to a refined humate solution storage tank 8 via a decanter centrifuge 7. Specifically, the present invention achieves the purpose of obtaining a refined humate solution by subjecting the raw coal and alkali solution to an extraction reaction in the raw material reactor 3 and centrifuging them through the decanter centrifuge 7, laying the foundation for the subsequent flocculation reaction.

[0020] 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-and-frame filter press 11, and the solid phase outlet of the first plate-and-frame filter press 11 is connected to the calcium / magnesium humate temporary storage tank 12. This 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 or adjusting the pH value, thereby achieving the purification and separation of humic acid.

[0021] 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. This arrangement allows the calcium / magnesium humate intermediate product to enter the sulfurous acid reduction reaction unit for a reduction reaction to obtain a calcium / magnesium sulfite precipitate, and utilizes excess sulfur dioxide to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium bisulfite, and finally to produce 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.

[0022] Furthermore, the liquid phase outlet of the first plate and 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 and frame filter press 11 can be recovered to achieve the feature of repeated reuse.

[0023] Furthermore, the outlet of the calcium / magnesium humate temporary storage tank 12 is connected to the calcium / magnesium humate product storage tank 18 via a 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.

[0024] Furthermore, 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. The water washing device 19 described in the present invention includes a desalted water tank, a belt conveyor, and a fully automatic desalted water washing machine, which can be purchased directly on the market, so the structure is not described in detail. After desalting by water washing, 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. Furthermore, 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 bisulfite / magnesium solution storage tank 22, the outlet of the calcium bisulfite / magnesium 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 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 via a filter 16. The utility model 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, meeting environmental protection requirements and reducing production risks.

[0025] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising: allowing raw coal in a raw material storage tank 1 to enter a humate refining unit, extracting humic acid from the raw coal using alkaline solution to obtain a humate solution, utilizing the property of humic acid complexing divalent metal ions to form a precipitate, using a high-concentration hard water flocculation reaction unit to combine high-concentration calcium and magnesium ions with humate to flocculate to obtain a calcium-magnesium humate intermediate product; allowing the above-mentioned calcium-magnesium humate intermediate product to enter a sulfite reduction reaction unit for a reduction reaction to obtain a calcium-magnesium sulfite precipitate, and using excess sulfur dioxide to convert the calcium / magnesium sulfite precipitate into soluble calcium / magnesium bisulfite, finally obtaining a high-purity humic acid product through water washing and drying in a high-purity humic acid treatment unit, and entering a high-purity humic acid product storage tank 2.

[0026] A production process for preparing high-purity humic acid using flocculation technology, the production process comprising the following steps:

[0027] 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 are respectively added to the raw material reactor 3 to make the mass ratio of raw coal, alkali and water into 8-10:10:20. The raw material reactor 3 is stirred and heated to 120-160°C and reacted for 2 hours;

[0028] Step 2: The reaction liquid after the reaction in the raw material reactor 3 is sent to the crude humate solution storage tank 6 for temporary storage. The crude humate solution temporarily stored in the crude humate solution storage tank 6 is sent to a horizontal screw centrifuge 7 for centrifugation to remove insoluble matter. The centrifuged liquid is sent to the refined humate solution storage tank 8 for temporary storage.

[0029] Step 3: The centrifuge liquid in the refined humate solution storage tank 8 enters the flocculation reaction tank 9, and simultaneously the high-concentration hard water with a hardness of 150-200 in the high-concentration hard water storage tank 10 is fed into the flocculation reaction tank 9. The reaction liquid of the above two is stirred and reacted for 3 hours and then fed into the first plate and frame filter press 11 for pressure filtration; the mass ratio of the high-concentration hard water to the centrifuge liquid is 20-30:1;

[0030] Step 4: The filter cake after filtration through the first plate and frame filter press 11 is a flocculated calcium / magnesium humate intermediate product. The calcium / magnesium humate is temporarily stored in the calcium / magnesium humate temporary storage tank 12; and is sent to the calcium / magnesium humate product storage tank 18 for sale as needed, or sent to the sulfite reduction reaction unit for preparation of 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, is sent to the calcium / magnesium humate product storage tank 18 for temporary storage and sale;

[0031] 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;

[0032] The following reaction occurs in the sulfurous acid solution storage tank 13:

[0033] HA-Ca / Mg+H2SO3→HA+Ca / MgSO3(precipitation)

[0034] Ca / Mg SO3(precipitate)+SO2(excess)→Ca / Mg(HSO3)2(solution)

[0035] The insoluble humic acid obtained by the above reaction is separated by precipitation;

[0036] Step 6: The reactants in the sulfurous acid solution storage tank 13 enter the second plate-and-frame filter press 15 for filtration. The filter cake is the humic acid product. The humic acid product passes through the water washing device 19 in the high-purity humic acid processing unit for water washing and desalination, and then passes through the second dryer 20 for drying before being 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.

[0037] Step 7: The washing liquid after washing in 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. The temporarily stored calcium bisulfite / magnesium solution is sent to the dilute hydrochloric acid solution storage tank 21 for reaction. The reaction is as follows:

[0038] Ca / Mg(HSO3)2+HCl→SO2(gas)+Ca / Mg(Cl)2

[0039] The sulfur dioxide gas generated by the above reaction enters the sulfur dioxide gas tank 14 for reuse;

[0040] 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. The liquid phase after filtration and impurity removal is sent to the high-concentration hard water storage tank 10 for reuse.

[0041] The utility model adopts a method for flocculating and reducing raw coal after alkali dissolution. After humic acid in the raw coal is extracted by alkali solution to obtain a humate solution, an acid solution is no longer used to precipitate the humic acid. Instead, the property of humic acid complexing divalent metal ions to form a precipitate is utilized. High-concentration calcium and magnesium ions are used to treat the humate solution for rapid flocculation to obtain a humate calcium-magnesium intermediate product. Then, more acidic sulfurous acid is used to displace the humic acid, 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 soluble calcium-hydrogen sulfite / magnesium. After washing and removing, a high-purity humic acid product is obtained. Dilute hydrochloric acid is reacted with calcium / magnesium bisulfite to displace sulfur dioxide for recycling, and the resulting calcium chloride / magnesium solution is transferred to a high-concentration hard water storage tank for recycling after treatment. The above process is completely closed, and no waste gas or waste acid liquid is discharged. The sulfurous acid used does not corrode equipment and is also inexpensive, which significantly reduces production costs while meeting environmental protection requirements and reducing production risks. In addition, the hard water used is non-toxic, easily available, and inexpensive, which significantly reduces production costs. No acid mist is generated in the closed pipeline, making the entire process environmentally friendly and pollution-free. Moreover, the humic acid product obtained undergoes multi-stage separation and has low impurities and high purity.

[0042] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and 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.

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) through the 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 bisulfite / magnesium solution storage tank (22), the outlet of the calcium bisulfite / magnesium 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) through a filter (16).

Images