High-salt organic waste liquid incineration fly ash treatment device

Abstract

The utility model discloses a high-salt organic waste liquid incineration fly ash treatment device which comprises a dissolving unit, a weight removal unit, a filtering unit, a resin unit, a freezing crystallization unit, an evaporation crystallization unit, a conversion unit and an incineration unit which are connected. When the device is used for treating the organic waste liquid incineration fly ash, sodium chloride and sodium carbonate in the incineration fly ash can be separated, sodium hydroxide in the incineration fly ash can be converted into sodium carbonate for further utilization, and the economic benefit of hazardous waste treatment can be improved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment, and in particular to a device for treating dust and ash from the incineration of high-salt organic waste liquid. Background Technology

[0002] Distillation residues from the chemical industry are characterized by high salt and high organic content, and are also known as high-salt organic waste liquid. When this waste liquid is incinerated, the resulting dust has a complex composition, mainly consisting of sodium chloride, sodium carbonate, sodium hydroxide, and heavy metals. Due to the presence of heavy metals in this dust, it is generally disposed of as hazardous waste in rigid landfills, resulting in high disposal costs. Summary of the Invention

[0003] In view of the above-mentioned technical problems existing in the prior art, the present invention provides a high-salt organic waste liquid incineration dust removal and treatment device, which includes the following units:

[0004] The dissolution unit is used to dissolve the incineration dust to obtain wastewater containing heavy metal ions, sodium carbonate, sodium chloride and sodium hydroxide.

[0005] The heavy metal removal unit is connected to the discharge port of the dissolution unit. It is used to initially remove heavy metal ions from the wastewater to obtain heavy metal removal wastewater.

[0006] The filter unit has its inlet connected to the outlet of the degravation unit. It is used to remove insoluble impurities from the degravation wastewater to obtain filtered water.

[0007] The resin unit has its inlet connected to the outlet of the filter unit. It is used to remove calcium and magnesium ions and residual heavy metal ions from the filtered water to obtain resin effluent.

[0008] The freeze crystallization unit has an inlet connected to the outlet of the resin unit, which is used to freeze crystallize the resin effluent to obtain freeze crystals and freeze mother liquor. The freeze crystals contain sodium carbonate decahydrate, and the freeze mother liquor contains sodium chloride.

[0009] An evaporation crystallization unit is connected to the inlet of the evaporation crystallization unit and the outlet of the freezing crystallization unit for discharging the freezing mother liquor. It is used to evaporate and crystallize the freezing mother liquor to obtain evaporated crystals and evaporated mother liquor. The evaporated crystals contain sodium chloride and the evaporated mother liquor contains sodium hydroxide.

[0010] The conversion unit has one inlet connected to the outlet of the evaporation crystallization unit for discharging the mother liquor, and is used to convert sodium hydroxide in the mother liquor into sodium carbonate through flue gas to obtain conversion mother liquor containing sodium carbonate; the outlet of the conversion unit is connected to the other inlet of the freeze crystallization unit, so that the conversion mother liquor enters the freeze crystallization unit to participate in freeze crystallization.

[0011] The incineration unit has its outlet connected to another inlet of the conversion unit to supply flue gas.

[0012] Preferably, the above-mentioned device further includes a purification unit, which is located between the conversion unit and the incineration unit, and is used to purify the flue gas generated in the incineration unit. The purified flue gas enters the conversion unit and converts the sodium hydroxide in the evaporation mother liquor into sodium carbonate.

[0013] Preferably, the above-mentioned apparatus further includes a recrystallization unit, the inlet of which is connected to the outlet of the freezing crystallization unit for discharging frozen crystals, for recrystallizing the frozen crystals to obtain sodium carbonate product.

[0014] Preferably, the sodium carbonate product meets at least the Class II indicators specified in GB / T210—2022 Industrial Sodium Carbonate. Specifically, the sodium carbonate product contains Na2CO3 content of 98.0 wt% or more, preferably 98.8 wt% or more, more preferably 99.2 wt% or more, and even more preferably 99.4 wt% or more.

[0015] Preferably, the above-mentioned device further includes a feeding unit, the outlet of which is connected to the inlet of the dissolving unit, for feeding incineration dust into the dissolving unit.

[0016] Preferably, the above-mentioned apparatus further includes a refining unit, the inlet of which is connected to the outlet of the evaporation and crystallization unit for discharging the evaporated crystals, for refining the evaporated crystals to obtain refined sodium chloride.

[0017] Preferably, the refined sodium chloride at least meets the secondary indicators for industrial wet salt specified in GB / T 5462-2015 Industrial Salt. Specifically, the NaCl content in the refined sodium chloride is above 93.3 wt%, preferably above 95.0 wt%, more preferably above 96.0 wt%, even more preferably above 97.5 wt%, further preferably above 98.5 wt%, and most preferably above 99.1 wt%.

[0018] Preferably, the conversion unit is a carbon dioxide absorption tower.

[0019] The device of this invention treats organic waste liquid incineration dust by separating sodium chloride and sodium carbonate from the incineration dust and converting sodium hydroxide in the incineration dust into sodium carbonate for further utilization, thereby improving the economic efficiency of hazardous waste treatment. Furthermore, the device generates waste salt during operation, but the amount of waste salt is less than 5 wt% of the incineration dust, meaning that virtually no hazardous waste is generated during the entire treatment process, and the components in the dust can be fully recovered and utilized. Attached Figure Description

[0020] Figure 1 This diagram shows the connection of the incineration dust removal and ash treatment device in this utility model.

[0021] Reference numerals in the attached figures: 1-De-weighting unit; 2-Filtration unit; 3-Resin unit; 4-Freeze crystallization unit; 5-Evaporation crystallization unit; 6-Conversion unit; 7-Incineration unit. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0023] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0026] The incineration dust treated by this utility model device is a byproduct obtained after incinerating saline wastewater generated during the production of chemical catalysts in an incinerator. The main components of the dust are sodium chloride, sodium carbonate, and sodium hydroxide, with sodium chloride content ranging from 20% to 50%, sodium carbonate content ranging from 40% to 75%, and sodium hydroxide content ranging from 5% to 10%. It also contains small amounts of insoluble matter and heavy metals, mainly nickel, chromium, and copper.

[0027] Figure 1 This is a schematic diagram showing the connection of the incineration dust removal and ash treatment device in this embodiment. (Reference) Figure 1 Incineration dust is fed into a dissolution unit (not shown) through a feeding unit (not shown), where it is dissolved to obtain wastewater containing heavy metal ions, sodium carbonate, sodium chloride, and sodium hydroxide. Ni in the wastewater... 2+ The mass concentration was 1.285 mg / L, Cr 3+ The mass concentration of Cu is 0.383 mg / L. 2+ The mass concentration was 0.083 mg / L, Ca 2+ The mass concentration is 10600 mg / L. The solvent is pure water, which can be recycled water obtained from other production systems.

[0028] The dissolved wastewater enters the heavy metal removal unit 1. In this embodiment, sodium hydroxide is added to the heavy metal removal unit, and under alkaline conditions of pH = 11.4, heavy metal precipitates are separated, initially removing heavy metal ions from the wastewater to obtain de-precipitated wastewater. Of course, in other embodiments of wastewater treatment using the device of this invention, quicklime or similar materials can be added to the heavy metal removal unit. The pH adjustment method can be other processes commonly used in the prior art. The pH of the adjusted wastewater is preferably between 8 and 12. In this embodiment, the filtered heavy metal precipitate is outsourced for processing. Of course, the heavy metal precipitate can also be utilized as needed.

[0029] The wastewater containing heavy metals enters the filtration unit 2, where insoluble impurities, such as insoluble suspended solids, are removed to obtain filtered water.

[0030] The filtered water enters resin unit 3 to remove calcium and magnesium ions and residual heavy metal ions, yielding resin effluent. The ion concentration in the resin effluent is detected using ICP-MS, with a detection limit of 1 μg / kg. Ni in the resin effluent... 2+ Cr 3+ Cu 2+ Ca 2+ Mg 2+ None of the ions were detected, meaning their concentrations were all below 1 μg / kg. The above unit can effectively remove impurity ions from wastewater.

[0031] The resin effluent enters the freeze crystallization unit 4 for freeze crystallization. The freeze crystallization unit 4 operates at a temperature of -5 to 10°C, where frozen crystals and a mother liquor are obtained. The frozen crystals contain sodium carbonate decahydrate, and the mother liquor contains sodium chloride. In this embodiment, the sodium carbonate decahydrate content in the frozen crystals is above 99 wt%. The mother liquor then enters the evaporation crystallization unit 5 for evaporation crystallization. In this embodiment, the evaporation crystallization unit 5 operates at a temperature between 80 and 120°C, where evaporated crystals and an evaporation mother liquor are obtained. The evaporated crystals contain sodium chloride, and the evaporation mother liquor contains sodium chloride, sodium carbonate, and sodium hydroxide. In this embodiment, the sodium chloride content in the evaporation mother liquor at the evaporation endpoint is controlled to be 15 wt% to 20 wt%, and the sodium carbonate content is controlled to be 10 wt% to 15 wt%. The evaporation mother liquor enters the conversion unit 6, where the sodium hydroxide in the evaporation mother liquor is converted into sodium carbonate through purified flue gas, yielding a conversion mother liquor containing sodium carbonate. In this embodiment, the conversion unit 6 is a carbon dioxide absorption tower. The conversion mother liquor is sprayed downwards from the top of the tower. Carbon dioxide in the flue gas rises and neutralizes the sodium hydroxide in the mother liquor, yielding sodium carbonate. The purified flue gas is obtained by purifying the flue gas produced in incineration unit 7 through a purification unit (not shown). The conversion mother liquor flows back into the freeze crystallization unit 4 to participate in freeze crystallization, continuing to utilize the sodium carbonate within it.

[0032] This embodiment further refines the obtained frozen crystals and evaporated crystals separately. The frozen crystals are refined by recrystallization. Using a recrystallization unit (not shown) connected to the frozen crystallization unit 4, the frozen crystals are recrystallized to obtain sodium carbonate product. In this embodiment, the Na₂CO₃ content in the sodium carbonate product is 99.2 wt% or more, meeting the Class II superior grade indicators specified in GB / T210-2022 Industrial Sodium Carbonate. Furthermore, using a refining unit (not shown) connected to the evaporation crystallization unit 5, the evaporated crystals are further purified to obtain refined sodium chloride. In the refined sodium chloride, the NaCl content is 99.1 wt% or more, meeting the superior grade indicators for industrial dry salt specified in GB / T 5462-2015 Industrial Salt.

[0033] The device of this invention treats organic waste liquid incineration dust by separating sodium chloride and sodium carbonate from the incineration dust, and converting sodium hydroxide in the incineration dust into sodium carbonate for further utilization, thus improving the economic efficiency of hazardous waste treatment. Furthermore, virtually no hazardous waste is generated during the entire treatment process, making it an environmentally friendly incineration dust treatment solution.

[0034] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A device for treating dust and ash from the incineration of high-salt organic waste liquid, characterized in that, The device includes the following units: A dissolution unit is used to dissolve the incineration dust to obtain wastewater containing heavy metal ions, sodium carbonate, sodium chloride and sodium hydroxide; The heavy metal removal unit has its inlet connected to the outlet of the dissolving unit and is used to initially remove heavy metal ions from the wastewater to obtain heavy metal removal wastewater. A filtration unit, the inlet of which is connected to the outlet of the degravimetric unit, is used to remove insoluble impurities from the degravimetric wastewater to obtain filtered effluent. A resin unit, the inlet of which is connected to the outlet of the filter unit, is used to remove calcium and magnesium ions and residual heavy metal ions from the filtered water to obtain resin effluent. A freeze crystallization unit, wherein one inlet of the freeze crystallization unit is connected to the outlet of the resin unit, is used to freeze crystallize the resin effluent to obtain freeze crystals and freeze mother liquor, wherein the freeze crystals contain sodium carbonate decahydrate and the freeze mother liquor contains sodium chloride; An evaporation crystallization unit is provided, wherein the inlet of the evaporation crystallization unit is connected to the outlet of the freezing crystallization unit for discharging the freezing mother liquor, and is used to evaporate and crystallize the freezing mother liquor to obtain evaporation crystals and evaporation mother liquor, wherein the evaporation crystals contain sodium chloride and the evaporation mother liquor contains sodium hydroxide. The conversion unit has one inlet connected to the outlet of the evaporation crystallization unit for discharging the evaporation mother liquor, and is used to convert sodium hydroxide in the evaporation mother liquor into sodium carbonate through flue gas to obtain conversion mother liquor containing sodium carbonate; the outlet of the conversion unit is connected to the other inlet of the freeze crystallization unit, so that the conversion mother liquor enters the freeze crystallization unit to participate in freeze crystallization. The incineration unit has its outlet connected to another inlet of the conversion unit to supply the flue gas.

2. The apparatus as claimed in claim 1, characterized in that, The device also includes a purification unit located between the conversion unit and the incineration unit. The purification unit is used to purify the flue gas generated in the incineration unit. The purified flue gas enters the conversion unit and converts the sodium hydroxide in the evaporation mother liquor into sodium carbonate.

3. The apparatus as described in claim 1, characterized in that, The apparatus further includes a recrystallization unit, the inlet of which is connected to the outlet of the freezing crystallization unit for discharging frozen crystals, for recrystallizing the frozen crystals to obtain sodium carbonate product.

4. The apparatus as described in claim 3, characterized in that, The sodium carbonate product must at least meet the Class II indicators specified in GB / T210—2022 Industrial Sodium Carbonate.

5. The apparatus as claimed in claim 1, characterized in that, The device also includes a feeding unit, the outlet of which is connected to the inlet of the dissolving unit, for feeding the incineration dust into the dissolving unit.

6. The apparatus as claimed in claim 1, characterized in that, The apparatus further includes a refining unit, the inlet of which is connected to the outlet of the evaporation and crystallization unit for discharging the evaporated crystals, for refining the evaporated crystals to obtain refined sodium chloride.

7. The apparatus as claimed in claim 6, characterized in that, The refined sodium chloride must at least meet the secondary indicators for industrial wet salt specified in GB / T 5462-2015 Industrial Salt.

8. The apparatus as claimed in claim 1, characterized in that, The conversion unit is a carbon dioxide absorption tower.

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