Process flow for producing humic acid

Abstract

The invention provides a process flow for producing humic acid, which comprises the following steps: S1, providing raw material coal, and extracting the raw material coal to form a reaction material which is a humic acid extract; s2, carrying out solid-liquid separation on the reaction material through a horizontal screw centrifuge, so that the reaction material is divided into material slag and primary clarified liquor; s3, water is added into the material residues for washing, and a mixture of the material residues and the water is formed; and S4, separating the mixture through a horizontal screw centrifuge to form a crude material and a secondary clarified liquid. According to the technological process for producing the humic acid, by adding the horizontal screw centrifuge, efficient separation of solid material residues and clarified liquor in the humic acid extract is achieved, the yield and purity of the product are improved, and due to the fact that the material residues obtained after solid-liquid separation possibly contain residual solvents or impurities, the horizontal screw centrifuge is used for dehydration of the washed material residues, and the product yield is improved. The secondary clarified liquor capable of being prepared into a refined product is separated, and the quality and grade of the refined product are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of humic acid production, and particularly to a process flow for humic acid production. Background Art

[0002] Humic acid has a wide range of sources, including peat, lignite, weathered coal, etc. Its production process generally includes steps such as raw material collection, pretreatment, extraction, separation, purification, and drying. In the extraction process, common methods include alkali dissolution method, acid precipitation method, etc., to dissolve humic acid from the raw materials, and then through a series of separation and purification means to remove impurities and obtain high-purity humic acid products. The existing production process flow of sodium or potassium salts of humic acid can be referred to Figure 2 , extracting the raw coal in a reactor, putting the reaction materials into a sedimentation tank for primary precipitation, pumping the crude clarified liquid into a sedimentation centrifuge or inclined plate or inclined tube sedimentation device for solid-liquid separation, concentrating the clarified liquid in an evaporator and then sending it to a dryer to obtain a refined product. The residue separated by precipitation is put into a washing tank and washed with soft water multiple times. Raw coal with a humic acid content greater than 60% (dry basis) can also be used to produce crude products by dry or semi-dry methods, that is, directly drying without solid-liquid separation and concentration. The main process equipment for producing sodium (potassium) humate is a reactor with a heating jacket, a sedimentation centrifuge or inclined plate sedimentation device, an evaporator, a dryer, etc.

[0003] In the prior art, the process flow of humic acid production can be referred to Figure 3 , separating the reaction materials by traditional filtration and sedimentation methods. The production efficiency of sedimentation tanks and filter presses is low, resulting in unstable product quality, low grade of refined products, and the purity is usually about 80%.

[0004] Therefore, to solve the above problems, the present invention proposes a process flow for humic acid production that can improve the grade, purity, quality, and efficiency of refined products. Summary of the Invention

[0005] To solve the technical problems existing in the above-mentioned existing humic acid production process flow, the present invention provides a process flow for humic acid production.

[0006] According to an object of the present invention, the present invention provides a process flow for humic acid production, including the steps of:

[0007] S1. Providing raw coal, and forming reaction materials by extracting the raw coal. The reaction materials are humic acid extracts;

[0008] S2. Separating the solid and liquid of the reaction materials through a scroll centrifuge, so that the reaction materials are divided into slag and first-stage clarified liquid;

[0009] S3. Add the slag to water for washing to form a mixture of the slag and the water;

[0010] S4. Separate the mixture through a horizontal screw centrifuge to form a crude product and a secondary clarified liquid;

[0011] S5. Process the crude product to form a crude product; process the primary clarified liquid and the secondary clarified liquid to form a refined product.

[0012] Preferably, the step S1 includes:

[0013] S11. Provide raw coal, and mix the raw coal and water to form water coal;

[0014] S12. Add the water coal to a hydrocyclone for separation to form slag and an extract;

[0015] S13. Add the extract and an additive to a reaction kettle, the additive being KOH or NaOH, and the reaction kettle extracts the content at a preset temperature and for a preset time to form the reaction material.

[0016] Preferably, the additive is KOH, the preset temperature is 90 °C, and the preset time is 40 min.

[0017] Preferably, the insoluble matter index in the primary clarified liquid and the secondary clarified liquid is 3% - 5%.

[0018] Preferably, the step S3 includes:

[0019] S31. Add the slag and water in step S2 to a washing tank for washing to form a mixture of the slag and the water and washing water;

[0020] S32. Add the washing water to the reaction material in step S1.

[0021] Preferably, in the step S5, the step of processing the primary clarified liquid and the secondary clarified liquid to form a refined product includes:

[0022] S51. Add the primary clarified liquid and the secondary clarified liquid to a triple-effect evaporation system for concentration;

[0023] S52. Feed the concentrated primary clarified liquid and secondary clarified liquid into a high-pressure reaction kettle through a vacuum pump to finally form a refined product.

[0024] Preferably, in the step S5, granulate the crude product by drying and crushing to form a crude product.

[0025] Preferably, the process flow of humic acid production further includes the step:

[0026] S6. Pack the crude product and the refined product to make commercial ore-source potassium humate.

[0027] Preferably, the crude product and the refined product are packed by an automatic packing machine.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] In the production process of this humic acid, by adding a scroll centrifuge and using the scroll centrifuge for solid-liquid separation of the humic acid extract, the scroll centrifuge can quickly separate the undissolved solid impurities, macromolecular polymers, etc. from the humic acid extract, providing a relatively pure feed liquid for the subsequent purification step, realizing the efficient separation of the solid slag and the clarified liquid in the humic acid extract, improving the yield and purity of the product. Since the slag obtained after solid-liquid separation may still contain residual solvents or impurities, further, the scroll centrifuge is used for dewatering the slag after washing to separate the secondary clarified liquid that can be made into a refined product, improving the quality and grade of the refined product.

[0030] The present invention will be further described below in conjunction with the drawings and embodiments. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the overall process flow of the production process of a humic acid according to the present invention;

[0032] Figure 2 It is a schematic diagram of one of the process flows of humic acid production in the prior art;

[0033] Figure 3 It is a schematic diagram of another process flow of humic acid production in the prior art. Detailed Embodiments

[0034] The following description is used to explain the present invention in detail so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variants, improvements, equivalent solutions, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0035] The present invention provides a technical solution: a production process of humic acid, including the steps:

[0036] S1. Provide raw coal, and form a reaction material by extracting the raw coal. The reaction material is a humic acid extract;

[0037] S2. Separate the reaction materials by a horizontal scroll centrifuge to divide the reaction materials into slag and primary clarified liquid;

[0038] S3. Add water to the slag for washing to form a mixture of the slag and the water;

[0039] S4. Separate the mixture by a horizontal scroll centrifuge to form crude material and secondary clarified liquid;

[0040] S5. Process the crude material to form a crude product; process the primary clarified liquid and the secondary clarified liquid to form a refined product.

[0041] By adding a horizontal scroll centrifuge and using it for solid-liquid separation of humic acid extract, the horizontal scroll centrifuge can quickly separate undissolved solid impurities, macromolecular polymers, etc. from the humic acid extract, providing a relatively pure feed liquid for subsequent purification steps, achieving efficient separation of solid slag and clarified liquid in the humic acid extract, improving the product yield and purity. Since the slag obtained after solid-liquid separation may still contain residual solvents or impurities, further, use the horizontal scroll centrifuge for dehydration of the washed slag to separate the secondary clarified liquid that can be made into a refined product, improving the quality and grade of the refined product.

[0042] As a key equipment in the technological process of humic acid production, the horizontal scroll centrifuge has the following characteristics: 1. Large processing capacity, capable of continuous operation, high production efficiency, and low production cost; 2. Good separation effect, can effectively separate fine solid particles, and high product quality; 3. Strong adaptability, capable of handling fluctuations in the properties of raw materials and extraction liquids, meeting the requirements of different production processes; 4. Compact structure, stable operation, high degree of automation, and easy to operate.

[0043] The insoluble matter index in the primary clarified liquid and the secondary clarified liquid is 3% - 5%. That is, for the primary clarified liquid separated by the horizontal scroll centrifuge in step S2 and the primary clarified liquid separated by the horizontal scroll centrifuge in step S4, their insoluble matter index is 3% - 5%.

[0044] In this embodiment, step S1 includes:

[0045] S11. Provide raw coal, and mix the raw coal and water to form water coal;

[0046] S12. Add the water coal to a hydrocyclone for separation to form slag and extraction liquid;

[0047] S13. Add the extraction solution and the additive into the reaction kettle. The additive is KOH or NaOH. The reaction kettle extracts the content at a preset temperature and for a preset time to form the reaction material. Preferably, the additive is KOH, the preset temperature is about 90°C, and the preset time is about 40 min.

[0048] Step S3 includes:

[0049] S31. Add the slag and water in Step S2 into the washing tank for washing to form a mixture of the slag and water and washing water;

[0050] S32. Add the washing water into the reaction material in Step S1, which can realize the reuse of the washing water and avoid waste of raw materials.

[0051] In Step S5, the primary clarified liquid and the secondary clarified liquid are processed to form a refined product. The steps include:

[0052] S51. Add the primary clarified liquid and the secondary clarified liquid into a triple-effect evaporation system for concentration;

[0053] S52. Feed the concentrated primary clarified liquid and secondary clarified liquid into a high-pressure reaction kettle through a vacuum pump to finally form a refined product.

[0054] In Step S5, the crude material is granulated by drying and crushing to form a crude product.

[0055] The process flow of humic acid production further includes the step:

[0056] S6. Pack the crude product and the refined product to make commercial ore-source potassium humate. Preferably, the crude product and the refined product are packed by an automatic packing machine.

[0057] In summary, the optimization of the process flow of humic acid production greatly improves the production efficiency through the primary clarified liquid and secondary clarified liquid obtained by a horizontal screw centrifuge. The product purity can be increased from 80% to over 95%. Recycling the washing water to the reaction material reduces the labor cost and raw material consumption, achieving remarkable economic and social benefits.

[0058] The above embodiments are only used to illustrate the technical ideas and characteristics of the present invention. The purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of the patent adoption of the present invention cannot be limited only by this embodiment. That is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the scope of the patent of the present invention.

Claims

1. A process flow for producing humic acid, characterized in that: Includes steps: S1. Providing raw coal, extracting the raw coal to form a reaction material, wherein the reaction material is a humic acid extract; S2. The reaction mass is separated into solid and liquid by a decanter centrifuge, so that the reaction mass is divided into a slag and a primary clarified liquid; S3. The slag is added to water for washing to form a mixture of the slag and water; S4. The mixture is separated by a decanter centrifuge to form a crude material and a secondary clarified liquid; S5. Processing the crude material to form a crude product; processing the primary clarified liquid and the secondary clarified liquid to form a refined product.

2. A process flow for producing humic acid according to claim 1, characterized in that: The step S1 comprises: S11. Providing raw coal, mixing the raw coal and water to form water coal; S12. The water coal is added to a cyclone to separate the slag and the extract; S13. Add the extract and additive into a reactor, wherein the additive is KOH or NaOH, and extract the contents of the reactor at a preset temperature and a preset time to form the reaction material.

3. A process flow for producing humic acid according to claim 2, characterized in that: The additive is KOH, the preset temperature is 90° C., and the preset time is 40 minutes.

4. A process flow for producing humic acid according to claim 1, characterized in that: The insoluble matter index in the primary clarified liquid and the secondary clarified liquid is 3% to 5%.

5. A process flow for producing humic acid according to claim 1, characterized in that: The step S3 comprises: S31. adding the residue and water in step S2 into a washing tank for washing to form a mixture of the residue and the water and washing water; S32. Add the washing water into the reaction material in step S1.

6. A process flow for producing humic acid according to claim 1, characterized in that: In step S5, the first clarified liquid and the second clarified liquid are processed to form a refined product, and the steps include: S51. The primary clarified liquid and the secondary clarified liquid are added to a triple-effect evaporation system for concentration; S52. The concentrated primary clarified liquid and the secondary clarified liquid are sent to a high-pressure reactor through a vacuum pump to finally form a refined product.

7. A process flow for producing humic acid according to claim 1, characterized in that: In the step S5, the crude material is granulated by drying and crushing to form a crude product.

8. A process flow for producing humic acid according to claim 1, characterized in that: The process flow of humic acid production also includes the following steps: S6. Packing the crude product and the refined product to produce commercial mineral-source potassium humate.

9. A process flow for producing humic acid according to claim 8, characterized in that: The crude product and the refined product are packaged by an automatic packaging machine.

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