CN110642270A - Method for refining and treating industrial waste salt - Google Patents
Method for refining and treating industrial waste salt Download PDFInfo
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- CN110642270A CN110642270A CN201910936254.7A CN201910936254A CN110642270A CN 110642270 A CN110642270 A CN 110642270A CN 201910936254 A CN201910936254 A CN 201910936254A CN 110642270 A CN110642270 A CN 110642270A
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Abstract
The invention relates to a method for refining and treating industrial waste salt, which comprises the following steps: firstly, mixing industrial waste salt and a salt washing agent, carrying out pretreatment, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; secondly, carrying out salt dissolving on the obtained pretreatment salt, and then carrying out oxidation treatment to obtain primary treatment liquid; finally, the obtained primary treatment liquid is subjected to adsorption operation and fine filtration operation, and then crystallization is carried out to obtain refined crystal salt. The method realizes effective separation of organic matters and salt in the waste salt, ensures effective separation and removal of the organic matters in the industrial waste salt, removes other impurities in the industrial waste salt through adsorption and fine filtration, realizes refining of high-quality crystallized salt, has the advantages of simple process, low energy consumption, low cost and mild conditions, does not generate industrial three wastes in the treatment process, and is an environment-friendly refined salt process.
Description
Technical Field
The invention relates to the technical field of industrial waste salt recovery, in particular to a refining treatment method of industrial waste salt.
Background
The waste salt mainly comes from the chemical industry, has the characteristics of various types, complex components, various sources, high content of toxic and harmful substances, high treatment cost, great environmental hazard and the like, and is widely concerned by the public and managers. Meanwhile, with the increasing desire of people for green environment, the industrial waste salt must be reasonably treated with the gradual improvement of environmental protection requirements, so that the environment is harmlessly protected, and the effective comprehensive recycling of waste resources is realized.
The industrial salt is an important chemical raw material and a strategic national resource, and the industrial byproduct waste salt is recycled as industrial raw material salt or used for other research and development purposes, so that the pollution of the industrial byproduct waste salt to the environment can be eliminated, the salt resource can be fully utilized, and the byproduct recycling and the circular economy can be realized. The key point of the resource treatment of the industrial waste salt is to remove COD, heavy metals and other impurities in the industrial waste salt.
At present, common treatment methods for reducing COD in industrial waste salt include incineration method, high-temperature pyrolysis method, landfill method and the like. In CN104344407A, organic matters in industrial waste salt slag are removed by adopting a high-temperature cracking method, but the problem that the by-product salt is formed into rings and blocks in thermal equipment at high temperature is difficult to solve, and the treatment cost is high. In CN103267296A, organic substances in the industrial waste salt residues are removed by a high-temperature pyrolysis method, so that toxic and harmful chemical substances in the industrial byproduct waste salt residues are decomposed into volatile gases and effectively separated from solid salt. However, the above methods have the problems of high energy consumption, complex process and the like. The methods for removing heavy metals and other trace elements in industrial waste salt are mainly an oxidation-reduction precipitation method, a living body purification method, an electrolysis method and an adsorption method. In CN109867296A, a chemical precipitation method is adopted to remove metal ion impurities in industrial waste salt slag. In CN109704369A, impurity components such as metal ions in the salt solution are removed by adopting purification and impurity removal treatment and adopting technologies such as chemical precipitation, filtration and the like, so as to obtain a sodium sulfate product with less metal elements. But still has the problems of poor universality, complex process, low product purity and the like.
In conclusion, an efficient waste salt treatment mode is urgently needed to be developed, so that multistage efficient resource development and utilization of waste salt are realized, resource utilization of waste salt is maximized, and the aims of enterprise health and sustainable development are fulfilled.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a method for refining and treating industrial waste salt, which has the characteristics of simple process, high universality, low energy consumption, less investment, environmental friendliness and the like, and also has better industrial application prospect.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method of industrial waste salt refining treatment, the method comprising the steps of:
(1) mixing industrial waste salt and a salt washing agent, carrying out pretreatment, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid;
(3) and (3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystalline salt.
According to the invention, the process realizes effective separation of organic matters and salt in the waste salt, simultaneously reduces the consumption of an oxidant in the oxidation process, ensures effective separation and removal of the organic matters in the industrial waste salt, removes other impurities in the industrial waste salt through adsorption and fine filtration, realizes refining of high-quality crystalline salt, and maximizes resource utilization of the waste salt. The method has the advantages of simple flow, low energy consumption, low cost and mild conditions, and industrial three wastes are not generated in the treatment process, so the method is an environment-friendly refined salt process.
As a preferable technical scheme of the invention, the industrial waste salt in the step (1) is an inorganic sodium salt.
Preferably, the inorganic sodium salt is a waste sodium chloride salt or a waste sodium sulfate salt.
Preferably, the salt content of the industrial waste salt in the step (1) is 50-97%, for example, 50%, 60%, 70%, 80%, 90% or 97%, etc., but not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferable technical scheme of the invention, the salt-washing agent is an organic solvent.
Preferably, the organic solvent is a low-toxicity organic solvent having a boiling point of not higher than 100 ℃.
Preferably, the organic solvent is any one or a combination of at least two of methanol, ethanol, n-propanol, diethyl ether, petroleum ether, ethyl acetate or methyl acetate, and may be, for example, a combination of methanol and ethanol, a combination of ethanol and n-propanol, a combination of n-propanol and diethyl ether, a combination of diethyl ether and petroleum ether, a combination of petroleum ether and ethyl acetate or a combination of ethyl acetate and methyl acetate, etc., but is not limited to the listed combinations, and other combinations not listed within the scope are also applicable, preferably ethanol and/or petroleum ether.
Preferably, the volume-to-mass ratio (m) of the salt washing agent in the step (1) to the industrial waste salt3The value of/t) is (1-10):1, and may be, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned value range are also applicable, and (3-8):1 is preferable.
The salt-washing solvent is an organic solvent, and the salt-washing solvent is selected to ensure that the salt-washing solvent and organic matters in industrial waste salt have universal solubility, and the salt is almost insoluble in the salt-washing solvent, so that the effective separation of the organic matters and the salt is ensured.
As a preferred technical scheme of the invention, the pretreatment in the step (1) is rinsing.
Preferably, the rinsing mode is one of agitation rinsing or suspension rinsing.
Preferably, the temperature of the pretreatment is 5 to 90 ℃, for example, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃ or 90 ℃ and the like, but not limited to the recited values, and other values not recited in the range of the values are also applicable, preferably 10 to 40 ℃.
Preferably, the pretreatment time is 0.5 to 12 hours, and for example, 0.5 hour, 1 hour, 1.5 hour, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours, 10.5 hours, 11 hours, 11.5 hours, or 12 hours, etc., are acceptable, but not limited to the enumerated values, and other values within the range are also acceptable, preferably 1 to 6 hours.
The pretreatment process realizes the separation of organic matters and salt, and the salt washing agent containing the organic matters can be purified by a mild separation method, so that the recycling of the salt washing agent is realized, and the cost is reduced.
The organic matters which are easy to treat and most of the organic matters which are difficult to treat in the industrial waste salt can be separated through salt washing pretreatment, a small amount of the organic matters which are difficult to treat are remained in the salt, and the salts which are difficult to treat need to be removed in an oxidation mode. The oxidizing agent selected for the oxidation reaction has high oxidation electrode potential and high oxidation efficiency, and does not generate other salt impurities to influence the purity of the refined crystal salt product. Therefore, the choice of the oxidizing agent is related to the type of the industrial waste salt, and particularly for the inorganic sodium salt with oxidizing property, the type of the anion in the inorganic sodium salt is the same as or similar to that of the anion in the industrial waste salt, and the oxidizing property is ensured.
In a preferred embodiment of the present invention, the salt solution after salt neutralization in step (2) has a mass concentration of 10 to 30 wt%, for example, 10 wt%, 12 wt%, 15 wt%, 17 wt%, 20 wt%, 25 wt%, or 30 wt%, but the present invention is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.
Preferably, the solvent for the salt is water.
As a preferable technical scheme of the invention, the oxidation treatment mode in the step (2) adopts step-by-step oxidation.
Preferably, the step-wise oxidation includes preliminary oxidation and deep oxidation.
Preferably, the oxidant used in the preliminary oxidation includes one of hydrogen peroxide, sodium peroxide, ozone, oxygen or peroxyacetic acid and/or a combination of at least two of them, such as a combination of hydrogen peroxide and sodium peroxide, a combination of sodium peroxide and ozone, a combination of ozone and oxygen or a combination of oxygen and peroxyacetic acid, etc., but not limited to the listed combinations, and other combinations not listed in the scope are equally applicable, preferably hydrogen peroxide and/or ozone.
Preferably, the oxidizing agent for deep oxidation includes an inorganic acid oxide having an oxidizing property.
Preferably, when the industrial waste salt in step (1) is a sodium chloride waste salt, the deep oxidizing agent is one or a combination of at least two of sodium hypochlorite, sodium perchlorate, sodium chlorate or chlorine dioxide, and examples thereof include, but are not limited to, a combination of sodium hypochlorite and sodium perchlorate, a combination of sodium perchlorate and sodium chlorate or a combination of sodium chlorate and chlorine dioxide, and other combinations not listed are also applicable within the scope, and preferably sodium hypochlorite and/or chlorine dioxide.
Preferably, when the industrial waste salt in the step (1) is a sodium sulfate waste salt, the deep oxidizing agent is sodium persulfate and/or sodium peroxymonosulfate.
Preferably, the amount of the oxidizing agent used for the preliminary oxidation is 1 to 10 times, for example, 1 time, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, or 10 times the theoretical amount of the oxidizing agent used for oxidizing the organic matter in the industrial waste salt, and the like, and is not limited to the recited values, and other values not recited in the range of the values are also applicable, and preferably 2 to 8 times.
Preferably, the amount of the oxidizing agent used for the deep oxidation is 1 to 10 times, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, the theoretical amount of the oxidizing agent used for oxidizing the organic matter in the industrial waste salt, and is not limited to the recited values, and other values not recited in the above range are also applicable, and preferably 2 to 5 times.
Preferably, the temperature of the primary oxidation is 5 to 80 ℃, for example, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃, but not limited to the recited values, and other unrecited values within the range of the values are equally applicable, preferably 10 to 60 ℃.
Preferably, the reaction time of the preliminary oxidation is 0.5 to 6 hours, for example, 0.5 hour, 1 hour, 1.5 hour, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours, etc., but is not limited to the recited values, and other values not recited in the numerical range are also applicable, preferably 1 to 5 hours.
Preferably, the deep oxidation temperature is 10-60 ℃, for example, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃ or 60 ℃, but not limited to the values listed, and other values not listed in the range of values are equally applicable, preferably 20-50 ℃.
Preferably, the reaction time of the deep oxidation is 0.5 to 6 hours, and for example, 0.5 hour, 1 hour, 1.5 hour, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours, etc., but is not limited to the recited values, and other values not recited in the numerical range are also applicable, and preferably 1 to 5 hours.
Preferably, the process pH of the deep oxidation is <7, preferably 1-5.
Preferably, the oxidation treatment is carried out under stirring or mixed suspension.
The organic matter removal rate of the industrial waste salt after the treatment by combining salt washing and oxidation is more than 99 percent. The distributed oxidation aims at realizing the thorough oxidation of organic matters and reducing the cost, the primary oxidation aims at a large amount of organic matters which are easy to oxidize, and the oxidant is low in selective price and high in oxidation activity; deep oxidation aims at a small amount of organic matters which are difficult to remove, and the oxidant is selected from the oxidant which has high oxidation efficiency and relatively high price. The method has universality and can realize the removal of organic matters in industrial waste salt obtained by any process in the field of chemical industry. The other impurities in the industrial waste salt, such as chromaticity, heavy metals, solid suspended matters and the like are removed by adopting adsorption and fine filtration. The requirements for the performance of the adsorbent in the invention are strong adsorption capacity, good adsorption selectivity, large adsorption capacity, low adsorption equilibrium concentration, high mechanical strength, stable chemical property, easy regeneration and reutilization, wide sources of raw materials for preparation and low price.
In a preferred embodiment of the present invention, the initial pH of the adsorption operation in step (3) is 5 to 9, and may be, for example, 5, 6, 7, 8 or 9, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.
Preferably, the adsorption operation in step (3) comprises color removal and heavy metal removal.
Preferably, the adsorbent in the color removal includes one or a combination of at least two of activated carbon, zeolite, and activated clay, and examples thereof include a combination of activated carbon and zeolite, a combination of zeolite and activated clay, or a combination of activated carbon and activated clay, but the adsorbent is not limited to the above-mentioned combinations.
Preferably, the adsorbent used in the heavy metal removal comprises an organic adsorbent or an inorganic adsorbent.
Preferably, the inorganic adsorbent includes one or a combination of at least two of diatomaceous earth, molecular sieve, kaolin or graphene, and may be, for example, a combination of diatomaceous earth and molecular sieve, a combination of molecular sieve and kaolin or a combination of kaolin and graphene, but is not limited to the listed combinations, and other combinations not listed in this range are also applicable, and are preferably molecular sieve and/or diatomaceous earth.
Preferably, the organic adsorbent includes one or a combination of at least two of a fibrous adsorbent, a resin adsorbent, and a chitosan adsorbent, and examples thereof include a combination of a fibrous adsorbent and a resin adsorbent, a combination of a resin adsorbent and a chitosan adsorbent, and a combination of a chitosan adsorbent and a fibrous adsorbent, but are not limited to the above-mentioned combinations, and other combinations not listed in this range are also applicable.
Preferably, the fibrous adsorbent includes one or a combination of at least two of an ion exchange fiber adsorbent, a chelate fiber adsorbent, or an activated carbon fiber adsorbent, and examples thereof include, but are not limited to, a combination of an ion exchange fiber adsorbent and a chelate fiber adsorbent, a combination of a chelate fiber adsorbent and an activated carbon fiber adsorbent, or a combination of an activated carbon fiber adsorbent and an ion exchange fiber adsorbent, and other combinations not listed are also applicable within the scope.
Preferably, the ion exchange fiber adsorbent may be one or a combination of at least two of LSI-106, D001, D113, D301, etc., but is not limited thereto, and the present invention is not exhaustive for reasons of space and simplicity.
Preferably, the chelating fiber adsorbent may be one or a combination of at least two of LSC-Hg, LSC-As or LX-106A, etc., but is not limited thereto, and the present invention is not exhaustive for reasons of space and brevity.
Preferably, the resin-based adsorbent includes one or a combination of at least two of an amino group-containing chelate resin, an amide group-containing chelate resin, a nitrogen-containing chelate resin, and a sulfur-containing chelate resin, and examples thereof include a combination of an amino group-containing chelate resin and an acyl group-containing chelate resin, a combination of an acyl group-containing chelate resin and a nitrogen-containing chelate resin, and a combination of a nitrogen-containing chelate resin and a sulfur-containing chelate resin, but are not limited to the above-mentioned combinations, and other combinations not listed are also applicable within the scope.
Preferably, the amino-containing chelating resin may be one or a combination of at least two of LSC-100, LSC-500, etc., but is not limited thereto, and the invention is not exhaustive for reasons of space and brevity.
Preferably, the amide group-containing chelating resin may be one or a combination of at least two of MTS9300 or MTS9301, etc., but is not limited thereto, and the present invention is not exhaustive for reasons of space and brevity.
Preferably, the nitrogen-containing chelating resin may be one or a combination of at least two of TMMA, CH-90 or TADC1-6, etc., but is not limited thereto, and the invention is not exhaustive for reasons of space and brevity.
Preferably, the chelating resin containing sulfur may be one or a combination of at least two of LSC-400 or LSC-200, etc., but is not limited thereto, and the invention is not exhaustive for reasons of space and simplicity.
Preferably, the adsorbent after adsorbing heavy metals in the adsorption operation in step (3) is solidified to prepare a mineral composite.
Preferably, the fine filtration operation of step (3) comprises microfiltration and/or ultrafiltration, preferably ultrafiltration.
Preferably, the pressure of the ultrafiltration is 0.1-0.5 MPa.
As a preferred technical scheme of the invention, the crystallization mode in the step (3) is multi-effect evaporation and/or MVR evaporation, and preferably MVR evaporation.
Preferably, the residue formed by crystallization in step (3) is solidified to prepare a mineral composite.
Preferably, the refined crystalline salt of step (3) is used as a refined salt product or as an industrial raw material.
Preferably, the industry comprises the caustic soda industry, the soda ash industry or the sodium sulfide industry.
Heavy metal in the industrial waste salt is removed through adsorption, the removed heavy metal still belongs to dangerous waste, the heavy metal and kettle residues generated in the evaporation process are subjected to high-temperature treatment and solidification in an immobilization and harmless mode, the removal of the heavy metal in the industrial waste salt is realized, secondary pollution is avoided, the obtained mineral state compound can be reused, and the efficient and multistage diversified utilization of various materials in the process is realized.
As a preferable technical scheme of the invention, the filtrate in the step (1) is used as a salt washing agent for multiple times of recycling.
Preferably, the end point of the multiple recycling of the filtrate is that the organic matter in the filtrate reaches the dissolution saturation.
Preferably, the organic matter in the filtrate can be used as fuel when the filtrate is saturated with the dissolved organic matter.
The salt washing solvent is used for dissolving and separating organic matters in the industrial waste salt, and after the salt washing solvent is recycled for many times, the salt washing solution contains a large amount of organic matters, has high heat value and can be used as fuel, so that the organic matters are thoroughly removed and the resource utilization of the organic matters is realized.
As a preferred technical scheme of the invention, the method comprises the following steps:
(1) mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 0.5-12h at 5-90 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is inorganic sodium salt; the inorganic sodium salt is waste sodium chloride salt or waste sodium sulfate salt; the content of salt in the industrial waste salt is 50-97%; the salt washing agent is an organic solvent; the organic solvent is a low-toxicity organic solvent with the boiling point not higher than 100 ℃; the organic solvent is any one or the combination of at least two of methanol, ethanol, n-propanol, diethyl ether, petroleum ether, ethyl acetate or methyl acetate; the volume mass ratio of the salt washing agent to the industrial waste salt is (1-10) to 1; the pretreatment is rinsing; the rinsing mode is one of stirring rinsing or suspension rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the solution value salt after salt dissolving is 10-30 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation comprises one of hydrogen peroxide, sodium peroxide, ozone, oxygen or peroxyacetic acid and/or the combination of at least two of the hydrogen peroxide, the sodium peroxide, the ozone and the peroxyacetic acid; the oxidant used for the deep oxidation comprises inorganic acid oxide with oxidizability; when the industrial waste salt in the step (1) is sodium chloride waste salt, the deep oxidant is one or the combination of at least two of sodium hypochlorite, sodium perchlorate, sodium chlorate or chlorine dioxide; when the industrial waste salt in the step (1) is sodium sulfate waste salt, the deep oxidizing agent is sodium persulfate and/or sodium peroxymonosulfate; the addition amount of the oxidant used for the primary oxidation is 1-10 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the addition amount of the oxidant used for deep oxidation is 1-10 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the temperature of the primary oxidation is 5-80 ℃; the reaction time of the primary oxidation is 0.5-6 h; the temperature of the deep oxidation is 10-60 ℃; the reaction time of the deep oxidation is 0.5-6 h; the process pH of the deep oxidation is < 7; the oxidation treatment is carried out under the condition of stirring or mixed suspension;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 5-9; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal comprises one or the combination of at least two of activated carbon, zeolite or activated clay; the adsorbent used in the heavy metal removal comprises an organic adsorbent or an inorganic adsorbent; the inorganic adsorbent comprises one or a combination of at least two of diatomite, molecular sieve, kaolin or graphene; the organic adsorption comprises one or the combination of at least two of fiber adsorbents, resin adsorbents or chitosan adsorbents; the fiber adsorbent comprises one or the combination of at least two of ion exchange fiber adsorbent, chelating fiber adsorbent or activated carbon fiber adsorbent; the resin adsorbent comprises one or a combination of at least two of amino-containing chelate resin, amido-containing chelate resin, nitrogen-containing chelate resin or sulfur-containing chelate resin; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation comprises microfiltration and/or ultrafiltration; the pressure of the ultrafiltration is 0.1-0.5 MPa; the crystallization mode is multi-effect evaporation and/or MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
Compared with the prior art, the invention at least has the following beneficial effects:
(1) the industrial waste salt treated by the method for washing salt and removing organic matters through oxidation avoids high energy consumption and pollution of incineration tail gas caused by adopting an incineration method;
(2) the temperature in the waste salt treatment process is lower than 100 ℃, and the control is easy;
(3) the salt washing agent is recycled, so that the resource utilization rate can be improved and the production cost can be reduced;
(4) adsorbing and fine filtering to remove other impurities of the industrial waste salt to obtain high-quality refined crystal salt;
(5) the salt-washing solvent containing organic matters is used as fuel and the immobilization operation of heavy metals and kettle residues, so that the thorough removal and resource utilization of impurities in the industrial waste salt are realized.
Drawings
FIG. 1 is a process flow diagram of the present invention.
The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
As shown in fig. 1, firstly, adding industrial waste salt into a salt washing agent, mixing, rinsing, and performing solid-liquid separation after rinsing to obtain pretreated salt and filtrate; wherein the filtrate can be returned as a salt washing agent; then mixing the pretreatment salt with water to carry out salt dissolving, adding an oxidant into the pretreated salt to carry out oxidation, and obtaining primary treatment liquid after the oxidation is finished; finally, carrying out adsorption operation on the primary pretreatment liquid by using an adsorbent, carrying out fine filtration operation after the adsorption operation is finished, and crystallizing the obtained feed liquid after the fine filtration operation is finished to obtain refined crystalline salt; wherein, when the organic matter in the filtrate reaches the dissolution saturation, the filtrate can be used as fuel; the adsorbed adsorbent and the kettle residue in the crystallization can be prepared into a mineral compound after solidification treatment.
To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows:
example 1
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 6 hours at 60 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium chloride waste salt; the content of salt in the industrial waste salt is 80 percent; the salt washing agent is ethanol; the volume-mass ratio of the salt washing agent to the industrial waste salt is 6: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after salt dissolving and neutralization is 20 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is sodium peroxide; the oxidant used for deep oxidation is sodium hypochlorite; the addition amount of the oxidant used for the primary oxidation is 5 times of the theoretical mass of the oxidant required by the oxidation of the organic matters in the industrial waste salt; the addition amount of the oxidant used for deep oxidation is 3 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt; the temperature of the primary oxidation is 30 ℃; the reaction time of the primary oxidation is 3 hours; the temperature of the deep oxidation is 30 ℃; the reaction time of the deep oxidation is 3 h; the pH value in the deep oxidation process is 3; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 5; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated carbon; the adsorbent adopted in the heavy metal removal is diatomite and a chelating fiber adsorbent LX-106A; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is microfiltration; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt in the embodiment comes from a chemical plant in Jiangsu, and the treated refined crystal salt meets the requirements of the edible salt standard (GB 2721-2003). Specific data of the obtained refined salt are shown in table 1.
Example 2
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 1h at 20 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium sulfate waste salt; the content of salt in the industrial waste salt is 97 percent; the salt washing agent is methanol; the volume-mass ratio of the salt washing agent to the industrial waste salt is 1: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after the salt dissolving and the salt neutralizing is 30 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is hydrogen peroxide and ozone; the oxidant used for deep oxidation is sodium persulfate; the addition amount of the oxidant used for the preliminary oxidation is 3 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the hydrogen peroxide is 2 times of the theoretical mass, and the ozone is 1 time of the theoretical mass; the addition amount of the oxidant used for deep oxidation is 3 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt; the temperature of the primary oxidation is 60 ℃; the reaction time of the primary oxidation is 2 hours; the temperature of the deep oxidation is 60 ℃; the reaction time of the deep oxidation is 2 hours; the pH value of the deep oxidation process is 4; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 6; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated carbon clay; the adsorbent used in the heavy metal removal is chitosan adsorbent; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is ultrafiltration; the pressure of the ultrafiltration is 0.2 MPa; the crystallization mode is multi-effect evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt in the embodiment comes from a chemical plant in Hebei, and the treated refined crystal salt meets the requirements of superior products in the anhydrous sodium sulfate standard (GB/T6009-2014). Specific data of the obtained refined salt are shown in table 1.
Example 3
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 12 hours at 10 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium chloride waste salt; the salt content in the industrial waste salt is 50 percent; the salt washing agent is petroleum ether; the volume-mass ratio of the salt washing agent to the industrial waste salt is 10: 1; the pretreatment is rinsing; the rinsing mode is one of suspension rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after salt dissolving and neutralization is 25 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is peroxyacetic acid and oxygen; the oxidant used for the deep oxidation is perchloric acid dioxide; the addition amount of the oxidant used for the primary oxidation is 10 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the peroxyacetic acid is 5 times of the theoretical mass, and the oxygen is 5 times of the theoretical mass; the addition amount of the oxidant used for deep oxidation is 10 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt; the temperature of the primary oxidation is 10 ℃; the reaction time of the primary oxidation is 6 hours; the temperature of the deep oxidation is 10 ℃; the reaction time of the deep oxidation is 4 h; the pH value in the deep oxidation process is 3; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 7; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated carbon and zeolite; the adsorbents adopted in the heavy metal removal are molecular sieves, kaolin and LSC-100; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is ultrafiltration; the pressure of the ultrafiltration is 0.5 MPa; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt is from a chemical plant in Shandong, and the treated refined crystal salt can be used as a raw material of refined salt in the soda industry. Specific data of the obtained refined salt are shown in table 1.
Example 4
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 0.5h at 5 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium chloride waste salt; the content of salt in the industrial waste salt is 90 percent; the salt washing agent is diethyl ether; the volume-mass ratio of the salt washing agent to the industrial waste salt is 3: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after salt dissolving and neutralization is 10 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is ozone; the oxidant used for the deep oxidation is sodium perchlorate; the addition amount of the oxidant used for the primary oxidation is 2 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the addition amount of the oxidant used for the deep oxidation is 1 time of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the temperature of the primary oxidation is 5 ℃; the reaction time of the primary oxidation is 4 hours; the temperature of the deep oxidation is 20 ℃; the reaction time of the deep oxidation is 0.5 h; the pH value in the deep oxidation process is 1; the oxidation treatment is carried out under the condition of mixed suspension;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 7; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is zeolite; the adsorbents adopted in the heavy metal removal are D301 and LSC-400; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is microfiltration; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt in the embodiment comes from a chemical plant in Henan, and the treated refined crystal salt meets the requirements of the edible salt standard (GB 2721-2003). Specific data of the obtained refined salt are shown in table 1.
Example 5
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 8 hours at 90 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium sulfate waste salt; the salt content in the industrial waste salt is 60 percent; the salt washing agent is n-propanol; the volume-mass ratio of the salt washing agent to the industrial waste salt is 8: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after salt dissolving and neutralization is 15 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is hydrogen peroxide and oxygen; the oxidant used for deep oxidation is sodium peroxymonosulfate; the addition amount of the oxidant used for the preliminary oxidation is 6 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the hydrogen peroxide is 3 times of the theoretical mass, and the oxygen is 3 times of the theoretical mass; the addition amount of the oxidant used for deep oxidation is 6 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt; the temperature of the primary oxidation is 40 ℃; the reaction time of the primary oxidation is 5 h; the temperature of the deep oxidation is 40 ℃; the reaction time of the deep oxidation is 5 h; the pH value of the deep oxidation process is 5; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 7; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated clay; the adsorbent used in the heavy metal removal is graphene and activated carbon fiber adsorbent; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is ultrafiltration; the pressure of the ultrafiltration is 0.1 MPa; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt is from a chemical plant in Hebei, and the treated refined crystal salt can be used as a raw material in the sodium sulfide industry. Specific data of the obtained refined salt are shown in table 1.
Example 6
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 7 hours at 40 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium sulfate waste salt; the salt content in the industrial waste salt is 93 percent; the salt-washing agent is ethyl acetate and methyl acetate which are mixed in equal volume; the volume-mass ratio of the salt washing agent to the industrial waste salt is 5: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after the salt dissolving and the salt neutralizing is 27 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is hydrogen peroxide; the oxidizing agents used for the deep oxidation are sodium peroxymonosulfate and sodium persulfate; the addition amount of the oxidant used for the primary oxidation is 1 time of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the addition amount of the oxidant used for deep oxidation is 5 times of the theoretical mass of the oxidant required by oxidation of organic matters in the industrial waste salt, wherein the theoretical mass of sodium peroxymonosulfate is 3 times, and the theoretical mass of sodium persulfate is 2 times; the temperature of the primary oxidation is 25 ℃; the reaction time of the primary oxidation is 3 hours; the temperature of the deep oxidation is 50 ℃; the reaction time of the deep oxidation is 6 h; the pH value of the deep oxidation process is 5; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 9; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated carbon; the adsorbent used in the heavy metal removal is a mixture containing TADC1 and LSC-200; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is microfiltration; the crystallization mode is multi-effect evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt in the embodiment comes from a chemical plant in Hebei, and the treated refined crystal salt meets the first-class requirement in the anhydrous sodium sulfate standard (GB/T6009-2014). Specific data of the obtained refined salt are shown in table 1.
Example 7
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 3 hours at 30 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium chloride waste salt; the salt content in the industrial waste salt is 70 percent; the salt-washing agent is ethanol and methyl acetate which are mixed in equal volume; the volume-mass ratio of the salt washing agent to the industrial waste salt is 40: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after the salt neutralization is 18 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation is ozone and oxygen; the oxidant used for the deep oxidation is sodium perchlorate; the addition amount of the oxidant used for the preliminary oxidation is 4 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the theoretical mass of ozone is 2 times, and the theoretical mass of oxygen is 2 times; the addition amount of the oxidant used for deep oxidation is 4 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt; the temperature of the primary oxidation is 80 ℃; the reaction time of the primary oxidation is 3 hours; the temperature of the deep oxidation is 25 ℃; the reaction time of the deep oxidation is 4 h; the pH value in the deep oxidation process is 3; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 8; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is activated carbon and activated clay; the adsorbent adopted in the heavy metal removal is MTS 9300; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is ultrafiltration; the pressure of the ultrafiltration is 0.3 MPa; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt is from a chemical plant in Shandong, and the treated refined crystal salt can be used as a raw material of refined salt in the caustic soda industry. Specific data of the obtained refined salt are shown in table 1.
Example 8
(1) Mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 5 hours at 25 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is sodium chloride waste salt; the salt content in the industrial waste salt is 85 percent; the salt washing agent is ethanol; the volume-mass ratio of the salt washing agent to the industrial waste salt is 3: 1; the pretreatment is rinsing; the rinsing mode is stirring rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of the salt solution after the salt neutralization is 23 wt%; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the preliminary oxidation is ozone, oxygen and hydrogen peroxide; the oxidant used for the deep oxidation is sodium perchlorate and sodium hypochlorite; the addition amount of the oxidant used for the preliminary oxidation is 8 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the theoretical mass of ozone is 3 times, the theoretical mass of oxygen is 3 times, and the theoretical mass of hydrogen peroxide is 2 times; the addition amount of the oxidant used for deep oxidation is 3 times of the theoretical mass of the oxidant required by the oxidation of organic matters in the industrial waste salt, wherein the theoretical mass of the sodium subrecord is 1.5 times, and the theoretical mass of the sodium perchlorate is 1.5 times; the temperature of the primary oxidation is 25 ℃; the reaction time of the primary oxidation is 0.5 h; the temperature of the deep oxidation is 25 ℃; the reaction time of the deep oxidation is 1.5 h; the pH value in the deep oxidation process is 3; the oxidation treatment is carried out under the condition of stirring;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 7; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal is zeolite; the adsorbent used in the heavy metal removal is diatomite, chitosan adsorbent and LX-106A; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation is microfiltration; the crystallization mode is MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
The waste salt in the embodiment comes from a chemical plant in Henan, and the treated refined crystal salt meets the requirements of the edible salt standard (GB 2721-2003). Specific data of the obtained refined salt are shown in table 1.
TABLE 1 chemical composition of refined salt obtained in example
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (10)
1. A method for refining and processing industrial waste salt is characterized by comprising the following steps:
(1) mixing industrial waste salt and a salt washing agent, carrying out pretreatment, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid;
(3) and (3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystalline salt.
2. The method of claim 1, wherein the industrial waste salt of step (1) is an inorganic sodium salt;
preferably, the inorganic sodium salt is waste sodium chloride salt or waste sodium sulfate salt;
preferably, the content of salt in the industrial waste salt in the step (1) is 50-97%.
3. The method of claim 1 or 2, wherein the salt-washing agent of step (1) is an organic solvent;
preferably, the organic solvent is a low-toxicity organic solvent with a boiling point not higher than 100 ℃;
preferably, the organic solvent is any one or a combination of at least two of methanol, ethanol, n-propanol, diethyl ether, petroleum ether, ethyl acetate or methyl acetate, preferably ethanol and/or petroleum ether;
preferably, the volume mass ratio of the salt washing agent to the industrial waste salt in the step (1) is (1-10):1, preferably (3-8): 1.
4. The method of any one of claims 1 to 3, wherein the pretreatment of step (1) is rinsing;
preferably, the rinsing mode is one of stirring rinsing or suspension rinsing;
preferably, the temperature of the pretreatment is 5-90 ℃, preferably 10-40 ℃;
preferably, the time of the pretreatment is 0.5 to 12 hours, preferably 1 to 6 hours.
5. The method according to any one of claims 1 to 4, wherein the mass concentration of the salt in the solution after the salt dissolution in the step (2) is 10 to 30 wt%;
preferably, the solvent for the salt is water.
6. The method according to any one of claims 1 to 5, wherein the oxidation treatment in step (2) is stepwise oxidation;
preferably, the step-wise oxidation comprises preliminary oxidation and deep oxidation;
preferably, the oxidant used for the primary oxidation comprises one of hydrogen peroxide, sodium peroxide, ozone, oxygen or peroxyacetic acid and/or a combination of at least two of the hydrogen peroxide, the sodium peroxide, the ozone, the oxygen or the peroxyacetic acid, and is preferably hydrogen peroxide and/or ozone;
preferably, the oxidizing agent for deep oxidation comprises inorganic acid oxide with oxidizing property;
preferably, when the industrial waste salt in the step (1) is a sodium chloride waste salt, the deep oxidizing agent is one or a combination of at least two of sodium hypochlorite, sodium perchlorate, sodium chlorate or chlorine dioxide, preferably sodium hypochlorite and/or chlorine dioxide;
preferably, when the industrial waste salt in the step (1) is a sodium sulfate waste salt, the deep oxidizing agent is sodium persulfate and/or sodium peroxymonosulfate;
preferably, the addition amount of the oxidant used for the primary oxidation is 1-10 times, preferably 2-8 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt;
preferably, the adding amount of the oxidant used for deep oxidation is 1-10 times, preferably 2-5 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt;
preferably, the temperature of the primary oxidation is 5-80 ℃, preferably 10-60 ℃;
preferably, the reaction time of the primary oxidation is 0.5-6h, preferably 1-5 h;
preferably, the temperature of the deep oxidation is 10-60 ℃, preferably 20-50 ℃;
preferably, the reaction time of the deep oxidation is 0.5-6h, preferably 1-5 h;
preferably, the process pH of the deep oxidation is <7, preferably 1-5;
preferably, the oxidation treatment is carried out under stirring or mixed suspension.
7. The method according to any one of claims 1 to 6, wherein the adsorption operation of step (3) has an initial pH of 5 to 9;
preferably, the adsorption operation in the step (3) comprises color removal and heavy metal removal;
preferably, the adsorbent in the color removal comprises one or a combination of at least two of activated carbon, zeolite or activated clay, preferably activated carbon and/or activated clay;
preferably, the adsorbent used in the heavy metal removal comprises an organic adsorbent or an inorganic adsorbent;
preferably, the inorganic adsorbent comprises one or a combination of at least two of diatomaceous earth, molecular sieve, kaolin or graphene, preferably molecular sieve and/or diatomaceous earth;
preferably, the organic adsorption comprises one or a combination of at least two of a fiber adsorbent, a resin adsorbent or a chitosan adsorbent;
preferably, the fiber adsorbent comprises one or a combination of at least two of ion exchange fiber adsorbent, chelating fiber adsorbent or activated carbon fiber adsorbent;
preferably, the resin-based adsorbent comprises one or a combination of at least two of amino-containing chelate resin, amide-containing chelate resin, nitrogen-containing chelate resin or sulfur-containing chelate resin;
preferably, the adsorbent after adsorbing heavy metals in the adsorption operation in the step (3) is solidified to prepare a mineral state compound;
preferably, the fine filtration operation of step (3) comprises microfiltration and/or ultrafiltration, preferably ultrafiltration;
preferably, the pressure of the ultrafiltration is 0.1-0.5 MPa.
8. The process according to any one of claims 1 to 7, wherein the crystallization in step (3) is a multiple effect evaporation and/or MVR evaporation, preferably MVR evaporation;
preferably, the residue formed in the crystallization in step (3) is solidified to prepare a mineral state composite;
preferably, the refined crystalline salt in step (3) can be used as a refined salt product or as an industrial raw material;
preferably, the industry comprises the caustic soda industry, the soda ash industry or the sodium sulfide industry.
9. The method according to any one of claims 1 to 9, wherein the filtrate of step (1) is recycled as a salt-washing agent for a plurality of times;
preferably, the end point of the multiple recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation;
preferably, the organic matter in the filtrate can be used as fuel when the filtrate is saturated with the dissolved organic matter.
10. The method according to any one of claims 1 to 9, characterized in that it comprises the steps of:
(1) mixing industrial waste salt and a salt washing agent, carrying out pretreatment for 0.5-12h at 5-90 ℃, and then carrying out solid-liquid separation to obtain pretreated salt and filtrate; the industrial waste salt is inorganic sodium salt; the inorganic sodium salt is waste sodium chloride salt or waste sodium sulfate salt; the content of salt in the industrial waste salt is 50-97%; the salt washing agent is an organic solvent; the organic solvent is a low-toxicity organic solvent with the boiling point not higher than 100 ℃; the organic solvent is any one or the combination of at least two of methanol, ethanol, n-propanol, diethyl ether, petroleum ether, ethyl acetate or methyl acetate; the volume mass ratio of the salt washing agent to the industrial waste salt is (1-10) to 1; the pretreatment is rinsing; the rinsing mode is one of stirring rinsing or suspension rinsing;
(2) carrying out salt dissolving on the pretreatment salt obtained in the step (1), and then carrying out oxidation treatment to obtain primary treatment liquid; the mass concentration of salt in the solution after salt dissolving is 10-30 wt%; the solvent of the salt is water; the oxidation treatment mode adopts step-by-step oxidation; the step-by-step oxidation comprises primary oxidation and deep oxidation; the oxidant used for the primary oxidation comprises one of hydrogen peroxide, sodium peroxide, ozone, oxygen or peroxyacetic acid and/or the combination of at least two of the hydrogen peroxide, the sodium peroxide, the ozone and the peroxyacetic acid; the oxidant used for the deep oxidation comprises inorganic acid oxide with oxidizability; when the industrial waste salt in the step (1) is sodium chloride waste salt, the deep oxidant is one or the combination of at least two of sodium hypochlorite, sodium perchlorate, sodium chlorate or chlorine dioxide; when the industrial waste salt in the step (1) is sodium sulfate waste salt, the deep oxidizing agent is sodium persulfate and/or sodium peroxymonosulfate; the addition amount of the oxidant used for the primary oxidation is 1-10 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the addition amount of the oxidant used for deep oxidation is 1-10 times of the theoretical mass of the oxidant used for oxidizing the organic matters in the industrial waste salt; the temperature of the primary oxidation is 5-80 ℃; the reaction time of the primary oxidation is 0.5-6 h; the temperature of the deep oxidation is 10-60 ℃; the reaction time of the deep oxidation is 0.5-6 h; the pH value in the deep oxidation process is less than 7; the oxidation treatment is carried out under the condition of stirring or mixed suspension;
(3) sequentially carrying out adsorption operation and fine filtration operation on the primary treatment liquid obtained in the step (2), and then crystallizing to obtain refined crystal salt; the initial pH value of the adsorption operation is 5-9; the adsorption operation comprises chroma removal and heavy metal removal; the adsorbent in the chromaticity removal comprises one or the combination of at least two of activated carbon, zeolite or activated clay; the adsorbent used in the heavy metal removal comprises an organic adsorbent or an inorganic adsorbent; the inorganic adsorbent comprises one or a combination of at least two of diatomite, molecular sieve, kaolin or graphene; the organic adsorption comprises one or the combination of at least two of fiber adsorbents, resin adsorbents or chitosan adsorbents; the fiber adsorbent comprises one or the combination of at least two of ion exchange fiber adsorbent, chelating fiber adsorbent or activated carbon fiber adsorbent; the resin adsorbent comprises one or a combination of at least two of amino-containing chelate resin, amido-containing chelate resin, nitrogen-containing chelate resin or sulfur-containing chelate resin; preparing a mineral compound by solidifying the adsorbent which adsorbs the heavy metal in the adsorption operation; the fine filtration operation comprises microfiltration and/or ultrafiltration; the pressure of the ultrafiltration is 0.1-0.5 MPa; the crystallization mode is multi-effect evaporation and/or MVR evaporation; preparing a mineral state compound by solidifying kettle residues formed in the crystallization; the refined crystal salt can be used as a refined salt product or an industrial raw material; the industry comprises the caustic soda industry, the soda industry or the sodium sulfide industry;
wherein the filtrate is used as a salt washing agent for multiple recycling; the end point of the repeated recycling of the filtrate is that the organic matters in the filtrate reach dissolution saturation; and when the organic matters in the filtrate reach the dissolution saturation, the filtrate can be used as fuel.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113751469A (en) * | 2021-09-14 | 2021-12-07 | 浙江海禹环保科技有限公司 | Resource treatment method and device for industrial waste salt |
| CN114314615A (en) * | 2021-12-31 | 2022-04-12 | 浙江工业大学 | Resource treatment method of industrial waste salt containing organic matters |
| CN114436295A (en) * | 2022-01-07 | 2022-05-06 | 上海市机电设计研究院有限公司 | Purification and reuse method of industrial sodium sulfate waste salt |
| CN114558272A (en) * | 2022-01-11 | 2022-05-31 | 曹建岩 | Process for separating salt and harmful waste in waste salt |
| CN114590822A (en) * | 2022-03-11 | 2022-06-07 | 华之源(苏州)化工科技有限公司 | Method for refining waste salt containing organic matters |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113751469A (en) * | 2021-09-14 | 2021-12-07 | 浙江海禹环保科技有限公司 | Resource treatment method and device for industrial waste salt |
| CN113751469B (en) * | 2021-09-14 | 2022-06-03 | 浙江海禹环保科技有限公司 | Resource treatment method and device for industrial waste salt |
| CN114314615A (en) * | 2021-12-31 | 2022-04-12 | 浙江工业大学 | Resource treatment method of industrial waste salt containing organic matters |
| CN114436295A (en) * | 2022-01-07 | 2022-05-06 | 上海市机电设计研究院有限公司 | Purification and reuse method of industrial sodium sulfate waste salt |
| CN114436295B (en) * | 2022-01-07 | 2024-04-16 | 上海市机电设计研究院有限公司 | Purification and reuse method of industrial sodium sulfate waste salt |
| CN114558272A (en) * | 2022-01-11 | 2022-05-31 | 曹建岩 | Process for separating salt and harmful waste in waste salt |
| CN114590822A (en) * | 2022-03-11 | 2022-06-07 | 华之源(苏州)化工科技有限公司 | Method for refining waste salt containing organic matters |
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