CN111056682A - Evaporative concentration and sectional crystallization method for RO concentrated solution of landfill leachate - Google Patents
Evaporative concentration and sectional crystallization method for RO concentrated solution of landfill leachate Download PDFInfo
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/14—Purification
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- C02F1/02—Treatment of water, waste water, or sewage by heating
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Abstract
The invention belongs to the technical field of landfill leachate treatment, and particularly relates to a method for evaporating, concentrating and crystallizing a landfill leachate RO concentrated solution in a sectional manner. And (3) evaporating and concentrating the RO concentrated solution subjected to deep softening and organic matter purification pretreatment through an MVR evaporator, then evaporating and crystallizing through a forced circulation MVR evaporator, washing and drying crystals to obtain industrial-grade sodium chloride, further cooling and crystallizing crystallized mother liquor, and washing and drying the obtained crystals to obtain industrial-grade potassium chloride. The method adopts an MVR evaporator, a forced circulation MVR evaporator and a cooling crystallizer to carry out evaporation concentration fractional crystallization and water washing purification on the pretreated RO concentrated solution, sodium chloride and potassium chloride industrial salt products are obtained by controlling the evaporation concentration fractional crystallization and other process conditions in a segmented manner, and condensed water is recycled as circulating cooling water, so that the full treatment and resource utilization of the RO concentrated solution are achieved. The method is effective, economical, simple, wide in adaptability and stable in operation.
Description
Technical Field
The invention belongs to the technical field of landfill leachate treatment, and particularly relates to a full-scale treatment and resource utilization method of a landfill leachate RO concentrated solution.
Background
MBR + NF is the mainstream technology of landfill leachate, often in order to reuse reclaimed water or guarantee that total nitrogen reaches the standard in engineering, further adopts the RO unit to handle the NF effluent that is rich in monovalent ion (NF can intercept most of organic matters and divalent ions in the MBR effluent), therefore has produced the RO concentrate that accounts for about 20% -30% of leachate stock solution. It can be seen that the RO concentrate mainly contains monovalent ion inorganic salts, such as Na+、K+And Cl-And small amounts of organic and divalent ions (Ca)2+、Mg2+And SO4 2-) Generally, TDS is 25000-65000 mg/L, conductivity is 35-110mS/cm, pH is 6.5-8, COD and TOC are 100-450 mg/L and 30-150 mg/L respectively, and Ca2+、Mg2+And SO4 2-The concentration is between 100 and 800mg/L, and in addition, the contents of nitrate nitrogen, ammonia nitrogen and the like are lower.
At present, leachate RO concentrated solution is treated by methods of back-spraying an incinerator or a garbage bin, fly ash solidification and humidification, slag cooling, lime slurry replenishing water prepared by flue gas cooling, submerged combustion evaporation and the like, but the methods have the problems of high operation cost, incomplete absorption, secondary pollution generation or no proper treatment method for evaporating miscellaneous salts, and essentially the treatment methods are all performed by taking the RO concentrated solution as a whole, so the treatment result still has pollution characteristics of mixed salts and the like, and the method is difficult to have sustainability. Because the RO concentrated solution mainly contains NaCl and KCl monovalent salt, and divalent ions and organic matters with very low concentration, the water quality is simpler and cleaner on the whole, therefore, the divalent ions and the organic matters can be further purified, and simultaneously, the pollution such as scaling and the like which are possibly formed in the subsequent process can be avoided, and according to the different saturation solubilities of the NaCl and the KCl at different temperatures, industrial-grade NaCl and KCl are obtained by adopting an evaporation concentration fractional crystallization method for resource utilization, and condensed water can be recycled as well as reclaimed water, and the technical idea can realize the sustainable treatment of the RO concentrated solution of the percolate. However, the process technology based on the idea is still rare, so that a method for full treatment and resource utilization of the percolate RO concentrated solution with simple process, reasonable economy and strong adaptability needs to be further developed according to the idea.
Disclosure of Invention
The invention aims to provide an evaporation concentration sectional crystallization method for a landfill leachate RO concentrated solution, which utilizes the saturation solubility difference of sodium chloride and potassium chloride at different temperatures to realize the total treatment of the RO concentrated solution, the sectional recovery of industrial sodium chloride and potassium chloride and the reclaimed water recycling of condensed water through the technological processes of MVR evaporation concentration, forced circulation MVR evaporation crystallization, cooling crystallization and crystal water washing purification. The method is effective and simple, has wide applicability, stable operation and good economical efficiency.
In order to achieve the purpose, the invention adopts the following technical scheme:
a landfill leachate RO concentrated solution evaporation concentration sectional crystallization method comprises the following steps:
1) pumping the RO concentrated solution subjected to deep softening and organic matter purification into an MVR evaporator for evaporation concentration to obtain condensed water and concentrated mother solution A, conveying the concentrated mother solution A to a forced circulation MVR evaporation crystallizer for evaporation crystallization to obtain condensed water, evaporated crystallization mother solution B and sodium chloride crystal salt slurry, pumping the sodium chloride crystal salt slurry into a centrifuge for solid-liquid separation to obtain centrifugal clear solution A and sodium chloride crystals, conveying the sodium chloride crystals to a water washing tank, washing and then performing centrifugal separation to obtain centrifugal clear solution B and purified sodium chloride crystals, and drying and packaging the purified sodium chloride crystals to obtain industrial-grade sodium chloride;
2) feeding the evaporative crystallization mother liquor B obtained in the step 1) into a cooling and cooling tank to be separated out to obtain a cooling crystallization mother liquor C and potassium chloride crystal salt slurry, pumping the potassium chloride crystal salt slurry into a centrifuge to perform solid-liquid separation to obtain a centrifugal clear liquid C and potassium chloride crystals, conveying the potassium chloride crystals to a water washing tank, performing centrifugal separation after water washing to obtain a centrifugal clear liquid D and purified potassium chloride crystals, and drying and packaging the purified potassium chloride crystals to obtain industrial-grade potassium chloride;
3) mixing the centrifugal clear liquid A and the centrifugal clear liquid B obtained in the step 1), pumping the mixture back to the forced circulation MVR evaporative crystallizer for evaporative crystallization again;
4) mixing the MVR evaporator condensed water obtained in the step 1) with forced circulation MVR evaporation crystallizer condensed water to be used as circulating cooling water for recycling;
5) mixing the centrifugal clear liquid C, the centrifugal clear liquid D and most of the cooling crystallization mother liquid C obtained in the step 2), pumping the mixture back to the MVR evaporator, and evaporating and concentrating the mixture again;
6) humidifying or back-spraying and burning or drying a small part of the cooled crystallization mother liquor C obtained in the step 2) as fly ash to be solidified as miscellaneous salt so as to ensure the quality of the obtained sodium chloride and potassium chloride crystal salt.
Further, after deep softening and organic matter purification in the step 1), concentrating the RO concentrated solution in an MVR evaporator to TDS of 200 g/L-210 g/L.
Further, the TDS of the crystallization mother liquor 2 in the forced circulation MVR evaporative crystallizer in the step 1) is 410-430 g/L.
Further, the water content of the sodium chloride crystals in the salt slurry of the sodium chloride crystals in the step 1) is 5-12% after solid-liquid separation by a centrifugal machine.
Further, in the step 1), condensed water or tap water in the evaporation concentration or crystallization process can be used as washing water in the sodium chloride crystal washing tank, the pH value of the washing tank is adjusted to be 4-6 by concentrated hydrochloric acid, and the water content of the sodium chloride crystal washing tank is controlled to be 40-60%.
Further, cooling the crystallization tank in the step 2) to a temperature of less than 30 ℃.
Further, after solid-liquid separation of the potassium chloride crystal salt slurry in the step 2) by a centrifugal machine, the water content of the potassium chloride crystal is 3% -10%.
Further, in the step 2), tap water is used as washing water in the potassium chloride crystal washing tank, concentrated hydrochloric acid is used for adjusting the pH value of the washing tank to be 4-6, and the water content of the potassium chloride crystal washing tank is controlled to be 35% -55%.
Furthermore, the salt content in the part of the cooling crystallization mother liquor C which needs to be treated by humidifying or back-spraying incineration or drying for miscellaneous salt solidification and the like in the step 6) accounts for about 5wt% of the total salt content of the RO concentrated solution.
The invention has the following remarkable advantages:
(1) is effective, simple and economical. According to the method, an energy-saving MVR evaporator is used for evaporating and concentrating the RO concentrated solution, a forced circulation MVR evaporator capable of avoiding scaling is further adopted for sodium chloride crystallization at high temperature, potassium chloride crystals are separated out through cooling, mechanical stirring, washing and purification are respectively carried out on the sodium chloride crystals and the potassium chloride crystals separated through centrifugal solid-liquid separation, industrial-grade sodium chloride and potassium chloride are finally obtained, and condensed water also meets the water quality requirement of circulating cooling water. Therefore, the organic combination method can efficiently realize the full treatment and resource utilization of the RO concentrated solution and achieve near zero emission. Meanwhile, various main reactors used in the process flow are conventional, simple and economical.
(2) The process has wide applicability and stable operation. In the method, except that a small part of cooling crystallization mother liquor is treated by humidifying, back-spraying, burning or drying fly ash to solidify miscellaneous salt and the like, so as to lay the foundation that the obtained sodium chloride and potassium chloride crystals can meet the requirement of industrial salt purity, KCl in NaCl crystals formed by evaporation crystallization and NaCl and other main impurity components in KCl crystals formed by cooling crystallization are respectively washed off by a very simple water washing tank, and meanwhile, bicarbonate is converted into CO by adjusting pH to weak acidity2The bubbles overflow, the purity of the NaCl crystal and the KCl crystal is further effectively improved, so that the NaCl crystal and the KCl crystal which are washed by water and dried meet the standard requirements of the corresponding industrial salt purity and the like, the requirements on the process control conditions of evaporation and cooling fractional crystallization and the initially obtained crystal purity are not over strict, and the adaptability and the operation stability of the process are greatly enhanced.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
The process flow of the present invention is further described below with reference to FIG. 1.
The whole process comprises pretreatment, RO concentrated solution MVR evaporation concentration, concentrated mother solution forced circulation MVR evaporation crystallization, sodium chloride crystal salt slurry centrifugal separation, sodium chloride crystal washing, water washing mixed solution centrifugal separation, evaporation crystallization mother solution cooling crystallization, potassium chloride crystal salt slurry centrifugal separation, potassium chloride crystal washing, water washing mixed solution centrifugal separation and other treatment units.
The specific process is as follows:
(1) conveying RO concentrated solution which is obtained from a combined process of MBR + NF + RO of a percolate treatment plant and is subjected to deep softening and organic matter purification pretreatment to an MVR evaporator for evaporation concentration, and controlling TDS of concentrated mother liquor to reach 200 g/L-210 g/L to obtain condensed water and concentrated mother liquor; pumping the concentrated mother liquor into a forced circulation MVR evaporation crystallizer, controlling the TDS of the evaporation crystallization mother liquor to be 410-430 g/L, and obtaining sodium chloride crystal salt slurry, evaporation crystallization mother liquor and condensed water, wherein the condensed water can be used as circulating cooling water after being mixed with the condensed water generated by evaporation and concentration of an MVR evaporator; performing solid-liquid separation on the obtained sodium chloride crystal salt slurry through a centrifugal machine, and controlling the water content of the sodium chloride crystal to be 5-12% to obtain a centrifugal clear liquid and a sodium chloride crystal; conveying the sodium chloride crystals into a washing tank, using condensed water or tap water in the evaporation concentration or crystallization process as washing water, controlling the water content of the sodium chloride crystals in the washing tank to be between 40 and 60 percent, and adjusting the pH value of the washing water in the washing tank to be between 4 and 6 by using concentrated hydrochloric acid; washing with water, performing centrifugal separation to obtain a centrifugal clear liquid and purified sodium chloride crystals, and drying and packaging the purified sodium chloride crystals to obtain industrial-grade sodium chloride; mixing two kinds of centrifugal clear liquid obtained by centrifugal separation of sodium chloride crystal salt slurry and centrifugal separation of a sodium chloride crystal rinsing pool, pumping the mixture back to the forced circulation MVR evaporation crystallizer for evaporation crystallization again;
(2) discharging evaporative crystallization mother liquor obtained by the forced circulation MVR evaporative crystallizer into a cooling crystallization tank, and controlling cooling to be below 30 ℃ to obtain cooling crystallization mother liquor and potassium chloride crystal salt slurry; pumping the potassium chloride crystal salt slurry into a centrifuge for solid-liquid separation, and controlling the water content of potassium chloride crystals to be 3-10% to obtain a centrifugal clear liquid and potassium chloride crystals; conveying the potassium chloride crystals to a washing tank, using tap water as washing water, controlling the water content of the potassium chloride crystals in the washing tank to be 35-55%, and adjusting the pH of the washing water to be 4-6 by using concentrated hydrochloric acid; washing with water, performing centrifugal separation to obtain a centrifugal clear liquid and purified potassium chloride crystals, and drying and packaging the potassium chloride crystals purified by the water washing pool to obtain industrial-grade potassium chloride; mixing two kinds of centrifugal clear liquid obtained by centrifugal separation of potassium chloride crystal salt slurry and centrifugal separation of a potassium chloride crystal washing pool with most of cooling crystallization mother liquid obtained by cooling a crystallization pool, pumping the mixture back to the MVR evaporator, and evaporating and concentrating again;
(3) the condensed water obtained by the MVR evaporator and the forced circulation MVR evaporation crystallizer is mixed and then is reused as circulating cooling water;
(4) and (3) cooling a small part of the cooled crystallization mother liquor which is obtained by cooling the crystallization tank and accounts for 5 percent of the total salt content of the RO concentrated solution, and carrying out treatments such as humidifying or back-spraying incineration of fly ash or drying to obtain miscellaneous salt solidification and the like so as to ensure the quality of the obtained sodium chloride and potassium chloride crystal salt.
Examples
The present invention will be further explained by taking the evaporation concentration and fractional crystallization of RO concentrated solution in leachate treatment engineering of a certain household garbage incineration power plant as an example.
The scale of the percolate treatment project of the household garbage incineration power plant is 500 tons/day, and a combined process flow of UASB + secondary A/O + UF (MBR) + NF + RO is adopted. The treatment process produces about 100 tons of RO concentrated solution per day, and the water quality is as follows: pH of 7.6-8.3, TOC of 45-94 mg/L, conductivity of 56.8-74.6 mS/cm, Ca2+And Mg2+The concentration ranges of (A) and (B) are respectively 103-394 mg/L and 90-396 mg/L. The RO concentrated solution is subjected to deep softening and organic matter oxidation pretreatment, and the main water quality is as follows: pH of 4-6, TOC of 13-18 mg/L, TDS of 34000-41000 mg/L, Na+Between 8000 and 10000mg/L, K+Between 6200 and 7200mg/L, Cl-Between 17000 and 21000mg/L of Ca2+<1mg/L，Mg2+<0.1mg/L，SO4 2-60-400 mg/L.
Firstly, lifting the RO concentrated solution subjected to deep softening and organic matter oxidation pretreatment into an MVR evaporator through a pump for evaporation concentration, wherein the boiling temperature of the feed liquid is gradually increased due to the gradual increase of the salt content in the feed liquid along with the increase of the concentration multiple, when the TDS of the feed liquid reaches 200-210 g/L, the boiling temperature reaches 110-112 ℃, and the evaporation concentration stage is completed to generate evaporation mother liquor. Then, conveying the concentrated mother liquor into a forced circulation MVR evaporator for evaporation crystallization, controlling the TDS of the evaporated mother liquor to be about 420g/L in order to avoid potassium chloride in a crystallizer from being separated out, wherein the content of potassium chloride is about the solubility (211 g/L) of the potassium chloride at 80 ℃ under an RO concentrated liquor mixed salt system, so as to obtain sodium chloride crystal salt slurry, the evaporated crystallization mother liquor and condensed water, mixing the evaporated crystallization condensed water with the condensed water generated by evaporation concentration of the MVR evaporator, then keeping the TOC between 3 and 5mg/L, and enabling the conductivity to be 25 to 40 mu S/cm, so that the concentrated mother liquor can be reused as circulating cooling water; pumping the obtained sodium chloride crystal salt slurry into a double-material-pushing centrifuge for solid-liquid separation to obtain a centrifugal clear liquid and sodium chloride crystals, wherein the water content of the sodium chloride crystals is about 8 percent, and the purity of the sodium chloride crystals is about 93 percent; conveying the sodium chloride crystals into a washing tank for purification, using condensed water in the evaporation concentration or crystallization process as washing water, controlling the water content of the sodium chloride crystals in the washing tank to be about 50%, and adjusting the pH value of the washing water to be 4-5 by using concentrated hydrochloric acid; the water washing pool is mechanically stirred and fully mixed, then the mixture is pumped into a double-pusher centrifuge for solid-liquid separation to obtain a centrifugal clear liquid and purified sodium chloride crystals, the purity of the purified sodium chloride crystals after being dried is 97.8 percent, the requirement of a secondary project of refined industrial salt on the purity of sodium chloride crystals which is more than 97.5 percent in the GB/T5462-2015 industrial salt standard is met, meanwhile, heavy metal, water insoluble substances, organic matters, other impurities and the like in the crystallized salt meet the requirement, and the crystallized salt can be used as an industrial sodium chloride resource after being packaged; mixing two kinds of centrifugal clear liquid obtained by centrifugal separation of the obtained sodium chloride crystal salt slurry and centrifugal separation of a sodium chloride crystal rinsing pool, pumping the mixture back to the forced circulation MVR evaporator for evaporation and crystallization again; finally, discharging the evaporative crystallization mother liquor obtained by the forced circulation MVR evaporative crystallizer into a cooling crystallization tank, and controlling cooling to a temperature lower than 30 ℃ to obtain the cooled crystallization mother liquor and potassium chloride crystal salt slurry; pumping the potassium chloride crystal salt slurry into a double-pusher centrifuge for solid-liquid separation to obtain a centrifugal clear liquid and potassium chloride crystals, wherein the water content of the potassium chloride crystals is about 6 percent, and the purity of the potassium chloride crystals is about 94.6 percent; conveying the potassium chloride crystals into a washing tank for purification, using tap water as washing water, controlling the water content of the potassium chloride crystals in the washing tank to be about 45%, and adjusting the pH value of the washing water to be 4-5 by using concentrated hydrochloric acid; washing with water, performing centrifugal separation to obtain a centrifugal clear liquid and purified potassium chloride crystals, drying the purified potassium chloride crystals to ensure that the purity of the purified potassium chloride crystals reaches 97.3 percent, and packaging the crystals to be used as industrial potassium chloride resources, wherein the quality of the purified potassium chloride crystals meets the high-grade product standard of GB/T7118-2008 industrial potassium chloride; mixing two kinds of centrifugal clear liquid obtained by centrifugal separation of potassium chloride crystal salt slurry and centrifugal separation of a potassium chloride crystal washing pool with most of cooling crystallization mother liquid obtained by cooling a crystallization pool, pumping the mixture back to the MVR evaporator, and evaporating and concentrating again; in addition, in order to ensure the quality of the sodium chloride and potassium chloride crystallized salt, a small part of the cooled crystallized mother liquor which is about 5 percent of the total salt content of the RO concentrated solution and is obtained from the cooling crystallization tank is sent to a fly ash humidifying and solidifying workshop for disposal by a residual liquid pump.
The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.
Claims (9)
1. A landfill leachate RO concentrated solution evaporation concentration sectional crystallization method is characterized by comprising the following steps:
1) pumping the RO concentrated solution subjected to deep softening and organic matter purification into an MVR evaporator for evaporation concentration to obtain condensed water and concentrated mother solution A, conveying the concentrated mother solution A to a forced circulation MVR evaporation crystallizer for evaporation crystallization to obtain condensed water, evaporated crystallization mother solution B and sodium chloride crystal salt slurry, pumping the sodium chloride crystal salt slurry into a centrifuge for solid-liquid separation to obtain centrifugal clear solution A and sodium chloride crystals, conveying the sodium chloride crystals to a water washing tank, washing and then performing centrifugal separation to obtain centrifugal clear solution B and purified sodium chloride crystals, and drying and packaging the purified sodium chloride crystals to obtain industrial-grade sodium chloride;
2) feeding the evaporative crystallization mother liquor B obtained in the step 1) into a cooling and cooling tank to be separated out to obtain a cooling crystallization mother liquor C and potassium chloride crystal salt slurry, pumping the potassium chloride crystal salt slurry into a centrifuge to perform solid-liquid separation to obtain a centrifugal clear liquid C and potassium chloride crystals, conveying the potassium chloride crystals to a water washing tank, performing centrifugal separation after water washing to obtain a centrifugal clear liquid D and purified potassium chloride crystals, and drying and packaging the purified potassium chloride crystals to obtain industrial-grade potassium chloride;
3) mixing the centrifugal clear liquid A and the centrifugal clear liquid B obtained in the step 1), pumping the mixture back to the forced circulation MVR evaporative crystallizer for evaporative crystallization again;
4) mixing the MVR evaporator condensed water obtained in the step 1) with forced circulation MVR evaporation crystallizer condensed water to be used as circulating cooling water for recycling;
5) mixing the centrifugal clear liquid C, the centrifugal clear liquid D and most of the cooling crystallization mother liquid C obtained in the step 2), pumping the mixture back to the MVR evaporator, and evaporating and concentrating the mixture again;
6) humidifying or back-spraying and burning or drying a small part of the cooled crystallization mother liquor C obtained in the step 2) as fly ash to be solidified as miscellaneous salt so as to ensure the quality of the obtained sodium chloride and potassium chloride crystal salt.
2. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: after deep softening and organic matter purification in the step 1), concentrating RO concentrated solution in an MVR evaporator to TDS of 200 g/L-210 g/L.
3. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: the TDS of the crystallization mother liquor 2 in the forced circulation MVR evaporative crystallizer in the step 1) is 410-430 g/L.
4. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: in the step 1), the water content of the sodium chloride crystals is 5-12% after the sodium chloride crystal salt slurry is subjected to solid-liquid separation by a centrifugal machine.
5. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: in the step 1), condensed water or tap water in the evaporation concentration or crystallization process is used as washing water in the sodium chloride crystal washing tank, concentrated hydrochloric acid is used for adjusting the pH value of the washing tank to be 4-6, and the water content of the sodium chloride crystal washing tank is controlled to be 40-60%.
6. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: cooling the crystallization tank in the step 2) to a temperature of less than 30 ℃.
7. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: and (3) performing solid-liquid separation on the potassium chloride crystal salt slurry in the step 2) by using a centrifugal machine, wherein the water content of the potassium chloride crystal is 3-10%.
8. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: in the step 2), tap water is used as washing water in the potassium chloride crystal washing tank, concentrated hydrochloric acid is used for adjusting the pH value of the washing tank to be 4-6, and the water content of the potassium chloride crystal washing tank is controlled to be 35-55%.
9. The evaporative concentration sectional crystallization method for the landfill leachate RO concentrated solution of claim 1, characterized in that: in the step 6), the salt content of a small part of the cooling crystallization mother liquor C which needs to be humidified or sprayed back for incineration or drying as the solidification treatment of the miscellaneous salt accounts for 5wt% of the total salt content of the RO concentrated solution.
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| CN111072433A (en) * | 2020-01-22 | 2020-04-28 | 福州大学 | Method for purifying sodium chloride in humic acid liquid fertilizer |
| CN111661979A (en) * | 2020-06-08 | 2020-09-15 | 厦门嘉戎技术股份有限公司 | Leachate recycling method and device |
| CN111661979B (en) * | 2020-06-08 | 2022-05-13 | 厦门嘉戎技术股份有限公司 | Leachate recycling method and device |
| CN113149353A (en) * | 2021-04-20 | 2021-07-23 | 中山市天乙能源有限公司 | Leachate treatment process and system |
| CN115650256A (en) * | 2021-09-26 | 2023-01-31 | 华融化学股份有限公司 | Industrial potassium chloride purification process and production system |
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