Disclosure of Invention
In view of this, the technical problem to be solved by the present invention is to provide a comprehensive utilization method of an atmosphere condensate, which solves the problem of difficult treatment of fluorine-containing waste residues generated in the dry-process aluminum fluoride preparation process, and realizes clean production of fluorine chemical industry and efficient utilization of fluorine resources.
The invention provides a comprehensive utilization method of a large gas condensate, which comprises the following steps:
a) Carrying out primary reaction on the atmospheric condensate and primary hydrochloric acid to obtain primary reaction liquid, and filtering to obtain primary filtrate and primary filter cake;
carrying out secondary reaction on the primary filter cake and secondary hydrochloric acid to obtain secondary reaction liquid, and filtering to obtain secondary filtrate and a secondary filter cake; the atmospheric condensate is formed in the production process of aluminum fluoride;
b) Washing, drying and calcining the secondary filter cake to obtain high-purity aluminum fluoride;
reacting the primary filtrate with alkali metal chloride and an auxiliary agent to remove impurities, filtering, neutralizing and filtering again to obtain filtrate and ointment; washing and drying the ointment to obtain aluminum hydroxide; the filtrate was concentrated to give ammonium chloride.
Preferably, the concentration of the primary hydrochloric acid is 100 g/L-300 g/L; the concentration of the secondary hydrochloric acid is 100 g/L-300 g/L; the hydrochloric acid can be an industrial byproduct or a commodity sold in the market.
Preferably, the reaction temperature of the first-stage reaction is 40-70 ℃; the reaction time is 0.5 to 1 hour; the temperature of the second-stage reaction is 40-70 ℃; the reaction time is 0.5-1 h.
Preferably, the Al content in the first-stage filtrate is (0.23-0.24) C HCl g/L, the first-stage filtrate is used for preparing the aluminum hydroxide by the reaction in the step B).
Preferably, the alkali metal chloride is one or more of calcium chloride, magnesium chloride or barium chloride, and the adding amount is excessive adding amount, and the judgment standard of the excessive adding amount is as follows: the method is based on that new precipitates are not generated when the catalyst is added; the precipitate is specifically the precipitate of calcium fluorosilicate, calcium sulfate and calcium phosphate. The auxiliary agent is polyacrylamide, and the dosage is 0.05-0.5mg/L. Preferably, the neutralization in the step B) is specifically performed by ammonia water/ammonia gas; wherein Al is 3+ And NH 3 The molar ratio is 1: (3-3.05).
Preferably, the reaction temperature of the step B) is 20-50 ℃; the reaction time is 0.5-2 h.
Preferably, the mass percentage of each component in the big gas condensate is as follows: 45-55% of fluorine, 28-31% of aluminum, 1-4% of silicon dioxide and 0.5-2.5% of sulfate radical.
Preferably, the mass concentration of the first-stage reaction liquid in the step A) is 20-50%; the mass concentration of the secondary reaction liquid is 20-50%.
Preferably, the calcining temperature in the step B) is 400-700 ℃; the calcination time is 1-3 h. Compared with the prior art, the invention provides a comprehensive utilization method of a large gas condensate, which comprises the following steps: a) Carrying out primary reaction on the atmospheric condensate and primary hydrochloric acid to obtain primary reaction liquid, and filtering to obtain primary filtrate and primary filter cake; the first-stage filter cake and second-stage hydrochloric acid are subjected to second-stage reaction to obtain second-stage reaction liquid, and second-stage filtrate and second-stage filter cake are obtained through filtration; the atmospheric condensate is formed in the production process of aluminum fluoride; b) The second mentionedWashing, drying and calcining the grade filter cake to obtain high-purity aluminum fluoride; reacting the primary filtrate with calcium chloride to remove impurities, filtering, neutralizing, and filtering again to obtain filtrate and ointment; washing and drying the ointment to obtain aluminum hydroxide; the filtrate was concentrated to give ammonium chloride. The invention makes the reaction more complete by the reaction of the primary hydrochloric acid and the secondary hydrochloric acid, and simultaneously adds the alkali metal chloride impurity removal process, thereby solving the problem of SiF6 2- 、PO4 3- And SO4 2- The problem is accumulated in the system, and the product quality is further improved. The products with different purities, such as high-purity aluminum fluoride, industrial-grade aluminum hydroxide, ammonium chloride and the like, can be applied to different fields, and the resource recycling value is improved.
Detailed Description
The invention provides a comprehensive utilization method of a large gas condensate, and a person skilled in the art can use the contents to reference the contents and appropriately improve the process parameters to realize the comprehensive utilization method. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope of the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.
The invention provides a comprehensive utilization method of a large gas condensate, which comprises the following steps:
a) Carrying out primary reaction on the atmospheric condensate and primary hydrochloric acid to obtain primary reaction liquid, and filtering to obtain primary filtrate and primary filter cake;
carrying out secondary reaction on the primary filter cake and secondary hydrochloric acid to obtain secondary reaction liquid, and filtering to obtain secondary filtrate and a secondary filter cake; the atmospheric condensate is formed in the production process of aluminum fluoride;
b) Washing, drying and calcining the secondary filter cake to obtain high-purity aluminum fluoride;
reacting the primary filtrate with alkali metal chloride and an auxiliary agent to remove impurities, filtering, neutralizing and filtering again to obtain filtrate and ointment; washing and drying the ointment to obtain aluminum hydroxide; the filtrate was concentrated to give ammonium chloride.
The dry aluminum fluoride process mainly takes unpurified hydrogen fluoride gas produced by fluorite as a raw material to directly enter a fluidized bed gas-solid reaction with aluminum hydroxide to produce an aluminum fluoride product, the tail gas produced in the production process is carried with aluminum fluoride and aluminum oxide materials, most of particles are removed by a cyclone dust collection device, the high-temperature tail gas enters an atmosphere condensation spray tower to be cooled and absorbed, a part of fine materials still exist in absorption liquid, and the fine materials are deposited to form an atmosphere condensation material. According to the statistics of industrialized production, about 10-15kg of atmosphere condensed material is generated by producing 1 ton of dry-method aluminum fluoride, wherein the fluorine content is 45-55%, the aluminum content is 28-31%, the silicon dioxide content is 1-4%, and the sulfate radical content is 0.5-2.5%.
The comprehensive utilization method of the atmospheric condensate provided by the invention firstly carries out primary reaction on the atmospheric condensate and primary hydrochloric acid to obtain primary reaction liquid.
The concentration of the primary hydrochloric acid is preferably 100 g/L-300 g/L; specifically, the concentration may be 100g/L, 200g/L or 300g/L.
The temperature of the first-order reaction is preferably 40-70 ℃; the reaction time is 0.5-1 h.
The mass concentration of the first-stage reaction liquid is preferably 20-50%.
Filtering the first-stage reaction liquid to obtain first-stage filtrate and first-stage filter cake. The present invention is not limited to the specific filtration method, and those skilled in the art will be familiar with the method.
The first-stage filtrate of the invention contains 0.23-0.24 percent of C HCl g/L, the first-stage filtrate is used for preparing the aluminum hydroxide by the reaction of the step B). Wherein C is HCl The concentration of hydrochloric acid is defined as above in the present invention.
Meanwhile, the first-stage filter cake continues to a second-stage hydrochloric acid device for second-stage reaction. At this time, new hydrochloric acid is injected into the primary hydrochloric acid apparatus. The new atmospheric condensate is preferentially reacted in the secondary hydrochloric acid so as to make the hydrochloric acid fully utilized, and the invention can make the primary filtrate and the secondary filtrate circularly treat the atmospheric condensate.
And carrying out secondary reaction on the primary filter cake and secondary hydrochloric acid to obtain secondary reaction liquid, and filtering to obtain secondary filtrate and a secondary filter cake.
The concentration of the secondary hydrochloric acid is preferably 100 g/L-300 g/L; specifically, the concentration may be 100g/L, 200g/L or 300g/L.
The reaction temperature of the secondary reaction is preferably 40-70 ℃; the reaction time is 0.5-1 h.
The mass concentration of the secondary reaction liquid is preferably 20-50%.
The secondary filter cake is washed, dried and calcined to obtain the high-purity aluminum fluoride.
Wherein the calcining temperature is 400-700 ℃; the calcination time is 1-3 h. (ii) a
The first-stage filtrate reacts with alkali metal chloride and an auxiliary agent to remove impurities.
The alkali metal chloride is one or more of calcium chloride, magnesium chloride or barium chloride, the adding amount is excessive, and the excessive judgment standard is as follows: the method is based on that new precipitates are not generated when the catalyst is added; the precipitate is specifically the precipitate of fluorosilicate, sulfate and phosphate. The auxiliary agent is polyacrylamide, and the dosage is 0.05-0.5mg/L.
Filtering after removing impurities, and then neutralizing. The temperature of the neutralization reaction is preferably 20-50 ℃; the reaction time is 1-2 h.
The invention preferably adopts ammonia water/ammonia gas for neutralization; wherein Al is 3+ And NH 3 The molar ratio is 1: (3-3.05).
Neutralizing, and filtering again to obtain filtrate and ointment; the present invention is not limited to the specific filtration method, and those skilled in the art will be familiar with the method.
Wherein, the ointment is washed and dried to obtain the aluminum hydroxide.
The present invention is not limited to the specific washing and drying operations, and those skilled in the art will be familiar with the present invention.
The filtrate was concentrated to give ammonium chloride. Can be sold directly. The present invention is not limited to the specific procedure for the concentration, and those skilled in the art will be familiar with the present invention. Can be concentrated under reduced pressure.
The invention can also adopt fluorine chemical by-product fluorine-containing hydrochloric acid to react with the atmospheric condensate, and the reaction effect is the same.
The chemical reaction equation related by the invention mainly comprises:
Al 2 O 3 +6HCl→2AlCl 3 +3H 2 O
SiF 6 2- +2PO 4 3- +SO 4 2- +5Ca 2+ →CaSiF 6 ↓+Ca 3 (PO 4 ) 2 ↓+CaSO 4 ↓
AlCl 3 +3NH 3 .H 2 O→Al(OH) 3 ↓+3NH 4 Cl
according to the invention, by utilizing the property that aluminum fluoride is difficult to dissolve in an acidic solution and the solubility of impurities such as silicon, phosphorus, sulfate radicals and the like is increased in a strong acidic solution, the content of each impurity is effectively removed, and the superfine high-purity aluminum fluoride is prepared and used in high-end fields such as optical coating materials, ternary lithium battery material coating and the like. The method adopts alkali chloride to remove impurities such as silicon, phosphorus, sulfate radical and the like in the mother liquor, the prepared aluminum hydroxide has high purity and low impurity content, meets the production requirement of dry aluminum fluoride, and solves the problem of SiF6 2- 、PO4 3- And SO4 2- Problems that accumulate in the system. The method has the advantages of simple process, environmental protection, no secondary pollution, realization of high-efficiency and high-value comprehensive utilization of resources and creation of maximum value of resources.
The invention provides a comprehensive utilization method of a large gas condensate, which comprises the following steps: a) Carrying out primary reaction on the atmospheric condensate and primary hydrochloric acid to obtain primary reaction liquid, and filtering to obtain primary filtrate and primary filter cake; the first-stage filter cake and second-stage hydrochloric acid are subjected to second-stage reaction to obtain second-stage reaction liquid, and second-stage filtrate and second-stage filter cake are obtained through filtration; the atmospheric condensate is formed in the production process of aluminum fluoride; b) Washing, drying and calcining the secondary filter cake to obtain high-purity aluminum fluoride; reacting the primary filtrate with alkali metal chloride to remove impurities, filtering, neutralizing, and filtering again to obtain filtrate and ointment; washing and drying the ointment to obtain the aluminum hydroxide(ii) a The filtrate was concentrated to give ammonium chloride. The invention makes the reaction more complete by the reaction of the primary hydrochloric acid and the secondary hydrochloric acid, and simultaneously adds the alkali metal chloride impurity removal process, thereby solving the problem of SiF6 2- 、PO4 3- And SO4 2- The problem is accumulated in the system, and the product quality is further improved. The products with different purities, such as high-purity aluminum fluoride, industrial-grade aluminum hydroxide, ammonium chloride and the like, can be applied to different fields, and the resource recycling value is improved.
In order to further illustrate the present invention, the comprehensive utilization method of the atmospheric condensate provided by the present invention is described in detail with reference to the following examples.
Example 1
The method comprises the following steps: preparation of aluminium fluoride
100g of atmospheric condensate (F53.7%, al 29.22%, siO2 3.72%, SO 4) 2- 1.42%) into 100g/L primary hydrochloric acid solution, preparing slurry with mass concentration of 20%, and reacting at 70 deg.C for 0.5h; and after filtering, adding the primary filter cake into a 100g/L secondary hydrochloric acid solution, preparing slurry with the mass concentration of 20%, reacting for 0.5h at 70 ℃, filtering the reacted slurry, and washing, drying and calcining the obtained secondary filter cake to obtain 78.3g of high-purity aluminum fluoride.
Circularly treating the atmospheric condensate by the primary filtrate and the secondary filtrate until the Al content in the primary filtrate is as follows: 23.65g/L, and then entering the second step to prepare the aluminum hydroxide.
Step two: preparation of aluminium hydroxide
And (3) adding the primary filtrate generated in the first step into a synthesis kettle, adding polyacrylamide and excessive calcium chloride under stirring for reaction, and filtering to remove fluorine silicate, phosphate radical and sulfate radical. Adding ammonia water or ammonia gas and Al into the obtained mother liquor 3+ And NH 3 The molar ratio is 1: stirring and reacting at 3,20 ℃ for 2h, filtering to obtain ointment, washing and drying to obtain 26.80g of aluminum hydroxide. The obtained filtrate is concentrated to obtain ammonium chloride which can be directly sold for external use.
Example 2
The method comprises the following steps: preparation of aluminium fluoride
200g of atmospheric condensate is added into 200g/L of primary hydrochloric acid solution, slurry with the mass concentration of 35% is prepared, and the reaction is carried out for 0.5h at the temperature of 55 ℃; and after filtering, adding the primary filter cake into 200g/L of secondary hydrochloric acid solution, preparing slurry with the mass concentration of 35%, reacting for 0.5h at 55 ℃, filtering the reacted slurry, and washing, drying and calcining the obtained secondary filter cake to obtain 156.5g of high-purity aluminum fluoride.
Circularly treating the atmospheric condensate by the primary filtrate and the secondary filtrate until the Al content in the primary filtrate is as follows: 48.00g/L, and then the step II is carried out to prepare the aluminum hydroxide.
Step two: preparation of aluminium hydroxide
And (3) adding the primary filtrate generated in the first step into a synthesis kettle, adding polyacrylamide and excessive magnesium chloride under stirring for reaction, and filtering to remove fluorine silicate, phosphate radical and sulfate radical. Adding ammonia water or ammonia gas and Al into the obtained mother liquor 3+ And NH 3 The molar ratio is 1:3.05 Stirring and reacting for 1h at 35 ℃, filtering to obtain ointment, washing and drying to obtain 50.8g of aluminum hydroxide. The obtained filtrate is concentrated to obtain ammonium chloride which can be directly sold.
Example 3
The method comprises the following steps: preparation of aluminium fluoride
Adding 150g of atmospheric condensate into 300g/L of primary hydrochloric acid solution, preparing slurry with the mass concentration of 50%, and reacting for 1h at 40 ℃; and after filtering, adding the primary filter cake into 300g/L of secondary hydrochloric acid solution, preparing slurry with the mass concentration of 50%, reacting for 1h at 40 ℃, filtering the reacted slurry, and washing, drying and calcining the obtained secondary filter cake to obtain 117.4g of high-purity aluminum fluoride.
Circularly treating the atmospheric condensate by using the obtained primary filtrate and secondary filtrate until the Al content in the primary filtrate is as follows: 69.00g/L, and then entering the second step to prepare the aluminum hydroxide.
Step two: preparation of aluminium hydroxide
And (3) adding the primary filtrate generated in the step one into a synthesis kettle, adding polyacrylamide and excess barium chloride under stirring for reaction, and filtering to remove fluorine silicate, phosphate radical and sulfate radical. Adding ammonia water or ammonia gas into the obtained mother liquor,Al 3+ And NH 3 The molar ratio is 1:3.05 Stirring and reacting at 50 ℃ for 0.5h, filtering to obtain ointment, washing and drying to obtain 29.4g of aluminum hydroxide. The obtained filtrate is concentrated to obtain ammonium chloride which can be directly sold for external use.
Examples of the experiments
The high-purity aluminum fluoride and industrial aluminum hydroxide products prepared in the patent examples 1-3 are respectively detected, and the detection results are shown in tables 1-2.
TABLE 1 detection results of high-purity aluminum fluoride products obtained in examples 1 to 3
TABLE 2 detection results of the industrial aluminum hydroxide products obtained in examples 1 to 3
As can be seen from the data in tables 1-2, the aluminum fluoride product obtained by the invention has high purity and low impurity content, and the index meets the national standard requirement; the industrial aluminum hydroxide index meets the preparation requirement of dry-method aluminum fluoride.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.