Method for recovering sodium metaaluminate solution from raney nickel catalyst mother liquor to prepare sodium metaaluminate solution for water purification

Abstract

This invention belongs to the field of water purification agent technology, specifically relating to a method for preparing sodium aluminate solution for water purification by recovering sodium aluminate solution from Raney nickel catalyst mother liquor. The method includes the following steps: sedimentation: adding Raney nickel catalyst mother liquor into a container, adding a pretreatment composite agent, heating, and sedimentation; filtration: cooling to room temperature and filtering; and testing for Cr content. 2+ Fe 3+ The content and color of the solution are checked for compliance; concentration: the treated liquid is pumped into a reaction vessel, heated, and concentrated to obtain a semi-finished sodium aluminate liquid; filtration: a mixture of composite cellulose and calcined diatomaceous earth is added to the semi-finished sodium aluminate liquid and filtered to obtain a sodium aluminate solution; after modification, a sodium aluminate solution for water purification is obtained. This invention, through the addition of pretreatment composite agents and a mixture of composite cellulose and calcined diatomaceous earth, treats wastewater to reduce metal ions, thus meeting the requirements of a water purification agent.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water purifying agent, and particularly relates to a method for preparing water purifying sodium metaaluminate solution from sodium metaaluminate solution in Raney nickel catalyst mother liquor. BACKGROUND

[0002] In the process of producing catalyst, the Raney nickel catalyst manufacturer usually produces Raney nickel catalyst mother liquor containing sodium metaaluminate. The mother liquor contains metal ions and part of organic matter, so the color of the Raney nickel catalyst mother liquor is deep. Because the content of sodium metaaluminate is low and the impurities in water are too much, the Raney nickel catalyst mother liquor is difficult to purify to the extent that can be used as raw material, so most companies give up the recycling of the wastewater.

[0003] Sodium metaaluminate is usually used as a water purifying agent, which has high polymerization and condensation properties, and acts on the removal of suspended solids, colloidal substances and organic matter in water. The water purifying agent has two functions of flocculation and removal of specific ions. The flocculation efficiency of the conventional water purifying agent is poor, and the removal rate of ions is also low.

[0004] Patent CN104760978B discloses a deep purification process of high-concentration sodium aluminate solution. Industrial sodium aluminate solution is used as raw material, an electric field is introduced, and an oxidizing agent is added. The iron and other impurities form a difficult-to-dissolve precipitate and remove the organic matter. Then, lime is added to remove silicon, and the hydrated garnet is generated. The newly generated hydrated garnet adsorbs the above-mentioned impurities, a flocculating agent is added, and the iron, silicon and organic matter in the solution are further removed to obtain a first-stage purified solution. In the first-stage purified solution, a precipitating agent is added, and an adsorbent is added. After standing, filtration is performed to obtain a second-stage purified solution. The second-stage purified solution is subjected to deep filtration, and macroporous anion resin is filled in the filtration to obtain high-purity sodium aluminate solution. However, the patent itself is used for purifying high-concentration sodium aluminate solution, and the purification by using an electric field has high energy consumption and poor effect, so it is difficult to be truly applied in actual large-scale production. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a method for preparing water purifying sodium metaaluminate solution from sodium metaaluminate solution in Raney nickel catalyst mother liquor, which is reasonable in design and suitable for industrial production. The prepared water purifying sodium metaaluminate solution has high flocculation efficiency and ion removal rate.

[0006] The method for preparing water purifying sodium metaaluminate solution from sodium metaaluminate solution in Raney nickel catalyst mother liquor comprises the following steps:

[0007] sodium metaaluminate 25-30%;

[0008] water 60-70%;

[0009] Insoluble 5-10%;

[0010] Wherein:

[0011] Al2O3 mass fraction content of 10-13%, Na2O mass fraction content of 15-17%;

[0012] Water containing impurity ions Cr 2+ >300ppm, impurity ions Fe 3+ >50ppm;

[0013] The color of the Raney nickel catalyst mother liquor is 90-120 degrees; using platinum cobalt colorimeter test;

[0014] Including the following steps:

[0015] (1) sedimentation

[0016] The Raney nickel catalyst mother liquor is put into a container, a pretreatment composite reagent is added, heated, and settled;

[0017] (2) filtration

[0018] Cool to room temperature and filter;

[0019] (3) test index

[0020] Detect Cr 2+ , Fe 3+ Content and color, the qualified standard is: Cr 2+ <20ppm, Fe 3+ <10ppm, color <50 degrees; unqualified repeat step (1) and step (2), qualified then enter step (4);

[0021] (4) concentration

[0022] The treated liquid after passing the test is pumped into a reaction kettle, stirring is started, heating is started, and the temperature is raised to 105-110℃, after concentration, Al2O3 mass fraction content >16%, Na2O mass fraction content >17.5%, sodium metaaluminate liquid semi-finished product is obtained;

[0023] (5) filtration

[0024] A mixture of composite cellulose and calcined diatomite is added to the sodium metaaluminate liquid semi-finished product, so that Fe 3+ <8ppm; sedimentation and filtration, sodium metaaluminate solution is obtained;

[0025] (6) modification

[0026] The sodium metaaluminate solution after filtration in step (5) is cooled, a post-treatment modification reagent is added, and stirred until dissolved, to obtain a sodium metaaluminate solution for water purification.

[0027] The pre-treatment composite reagent in step (1) is a mixture of Na2S, H2O2 and CaCO3.

[0028] The pre-treatment composite reagent is a mixture of Na2S, H2O2 and CaCO3 in a mass ratio of 1:(1-3):(0.5-2).

[0029] The addition amount of the pre-treatment composite reagent in step (1) is 0.01-0.05% of the mass of the Raney nickel catalyst mother liquor.

[0030] The temperature in step (1) is raised to 60-70℃, and the settling time is 15-30 min.

[0031] The mixing mass ratio of the composite cellulose and calcined diatomite in step (5) is (1-3):(1-2).

[0032] The addition amount of the mixture of the composite cellulose and calcined diatomite in step (5) is 0.03-0.08% of the mass of the sodium metaaluminate liquid semi-finished product.

[0033] The cooling temperature in step (6) is 60-80℃.

[0034] The post-treatment modification reagent in step (6) is PAM.

[0035] The addition amount of the post-treatment modification reagent in step (6) is 1-3% of the mass of the sodium metaaluminate solution.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] (1) The present application can effectively reduce Cr 2+ >300ppm, impurity ions Fe 3+ >50ppm to Cr 2+ <20ppm, Fe 3+ <10ppm by adding the pre-treatment composite reagent in the pre-treatment step, which is conducive to the later treatment.

[0038] (2) The present application can increase the mass fraction of Al2O3 to more than 16% and the mass fraction of Na2O to more than 17.5% by the concentration process, so that the content of sodium metaaluminate in the later water purifying agent preparation process meets the standard.

[0039] (3) The present application can reduce the concentration of Fe 3+ to less than 8 ppm by using the mixture of composite cellulose and calcined diatomite to filter and adsorb Fe 3+ after concentration.

[0040] (4) The prepared water purifying agent has high flocculation efficiency and ion removal rate. DETAILED DESCRIPTION

[0041] The application will be further described in connection with the following examples, but the protection scope of the application is not limited to this.

[0042] All raw materials used in the examples are commercially available, except for special instructions.

[0043] Raw material name Factory Brand Na2S Aladdin S138149 H2O2 Lilang 3％ CaCO3 Jinhuitaiya Analytically pure Composite cellulose Lüjian Technology Calcined diatomite McMurry 200 mesh PAM Huahang Chemical 10 million of weight average molecular weight

[0044] Example 1

[0045] The method for preparing the sodium metaaluminate solution for water purification from the mother liquor of Raney nickel catalyst, the Raney nickel catalyst mother liquor is composed of the following mass fractions:

[0046] Sodium metaaluminate 28%;

[0047] Water 65%;

[0048] Insoluble matter 7%;

[0049] Among them:

[0050] The mass fraction content of Al2O3 is 12%, and the mass fraction content of Na2O is 16%;

[0051] The impurity ion Cr in the water is 450ppm, the impurity ion Fe is 153ppm; Cr 2+ : 450ppm, impurity ion Fe 3+ : 153ppm; Cr 2+ : 450ppm, impurity ion Fe 3+ HG-T4518-2013 standard is used for detection; Al2O3 and Na2O content are detected by HG-T4518-2013;

[0052] The colority of the Raney nickel catalyst mother liquor is 115 degrees; a platinum-cobalt colority tester is used for testing;

[0053] The method comprises the following steps:

[0054] (1) Sedimentation

[0055] The Raney nickel catalyst mother liquor is poured into a container, and a pretreatment composite reagent is added, which is a mixture of Na2S, H2O2 and CaCO3 with a mass ratio of 1:2:1, and the addition amount is 0.03% of the mass of the Raney nickel catalyst mother liquor, and the temperature is raised to 65℃, and the sedimentation is carried out for 20min;

[0056] (2) Filtration

[0057] Cooling to room temperature and filtering;

[0058] (3) Test index

[0059] Cr 2+ 16ppm, Fe 3+ 8ppm, color: 32 degrees;

[0060] (4) Concentration

[0061] The qualified treatment liquid is pumped into the reaction vessel, stirring and heating are started, and the temperature is raised to 108°C. After concentration, the Al2O3 mass fraction content is 16.5% and the Na2O mass fraction content is 19.9%, thus obtaining sodium aluminate liquid semi-finished product.

[0062] (5) Filtration

[0063] A mixture of composite cellulose and calcined diatomaceous earth in a mass ratio of 2:1 was added to the sodium aluminate liquid semi-finished product. The amount added was 0.05% of the mass of the sodium aluminate liquid semi-finished product, so that Fe 3+ 5 ppm; after sedimentation and filtration, sodium aluminate solution is obtained;

[0064] (6) Modification

[0065] Cool the filtered sodium aluminate solution from step (5) to 70°C, add PAM at 2% of the mass of the sodium aluminate solution, and stir until dissolved to obtain sodium aluminate solution for water purification.

[0066] Example 2

[0067] The method for preparing sodium aluminate solution for water purification by recovering sodium aluminate solution from Raney nickel catalyst mother liquor, wherein the Raney nickel catalyst mother liquor is composed of the following components by mass fraction:

[0068] Sodium aluminate 25%;

[0069] Water 65%;

[0070] Insoluble matter 10%;

[0071] in:

[0072] The mass fraction of Al2O3 is 10%, and the mass fraction of Na2O is 15%.

[0073] The water contains impurity ions Cr 2+ 434 ppm, impurity ion Fe 3+ 145ppm; Cr 2+ Fe was detected by ICP. 3+ The content of Al2O3 and Na2O was tested according to the HG-T4518-2013 standard.

[0074] The colority of the Raney nickel catalyst mother liquor is 108 degrees; a platinum-cobalt colorimeter is used for testing;

[0075] The method comprises the following steps:

[0076] (1) Sedimentation

[0077] The Raney nickel catalyst mother liquor is poured into a container, and a pretreatment composite reagent, a mixture of Na2S, H2O2 and CaCO3 in a mass ratio of 1:1:0.5, is added in an amount of 1 / 10,000 of the mass of the Raney nickel catalyst mother liquor. The temperature is raised to 60 DEG C, and the mixture is allowed to settle for 30 minutes.

[0078] (2) Filtration

[0079] The mixture is cooled to room temperature and filtered.

[0080] (3) Test index

[0081] Cr: 18 ppm, Fe: 9 ppm, colority: 35 degrees; 2+ 3+

[0082] (4) Concentration

[0083] The treated liquid that meets the requirements is pumped into a reaction kettle, and stirring and heating are started. The temperature is raised to 105 DEG C. After concentration, the mass fraction of Al2O3 is 16.3%, and the mass fraction of Na2O is 20.5%. Thus, a sodium metaaluminate liquid semi-product is obtained.

[0084] (5) Filtration

[0085] A mixture of composite cellulose and calcined diatomite in a mass ratio of 1:1 is added to the sodium metaaluminate liquid semi-product in an amount of 3 / 10,000 of the mass of the sodium metaaluminate liquid semi-product. Thus, Fe: 5 ppm; the mixture is allowed to settle and filter. Thus, a sodium metaaluminate solution is obtained. 3+

[0086] (6) Modification

[0087] The sodium metaaluminate solution obtained in step (5) is cooled to 60 DEG C, and PAM is added in an amount of 1% of the mass of the sodium metaaluminate solution. The mixture is stirred until the PAM is dissolved. Thus, a sodium metaaluminate solution for water purification is obtained.

[0088] Example 3

[0089] The method for preparing a sodium metaaluminate solution for water purification from a Raney nickel catalyst mother liquor, wherein the Raney nickel catalyst mother liquor comprises the following mass fractions:

[0090] Sodium metaaluminate 30%;

[0091] Water 65%; ​​​

[0092] Insoluble 5%;

[0093] Wherein:

[0094] Al2O3 mass fraction content of 13%, Na2O mass fraction content of 17%;

[0095] Impurity ions Cr in water 2+ >300ppm, impurity ions Fe 3+ >50ppm; Cr 2+ Fe by ICP detection 3+ HG-T4518-2013 standard is used for detection; Al2O3, Na2O content is detected by HG-T4518-2013;

[0096] The color of the Raney nickel catalyst mother liquor is 119 degrees; platinum-cobalt colorimeter is used for testing;

[0097] Including the following steps:

[0098] (1) Sedimentation

[0099] The Raney nickel catalyst mother liquor is put into a container, and a pretreatment composite reagent is added: a mixture of Na2S, H2O2 and CaCO3 with a mass ratio of 1:3:2, the addition amount is 0.05% of the mass of the Raney nickel catalyst mother liquor, and the temperature is raised to 70°C, and then settled for 15 minutes;

[0100] (2) Filtration

[0101] Cool to room temperature and filter;

[0102] (3) Test index

[0103] Cr 2+ : 19ppm, Fe 3+ : 9ppm, color: 36 degrees;

[0104] (4) Concentration

[0105] The treated liquid after passing the test is pumped into a reaction kettle, stirring is started, heating is started, and the temperature is raised to 110°C, after concentration, the mass fraction content of Al2O3 is 16.2%, the mass fraction content of Na2O is 18.7%, and the sodium metaaluminate liquid semi-product is obtained;

[0106] (5) Filtration

[0107] A mixture of composite cellulose and calcined diatomite with a mass ratio of 3:2 is added to the sodium metaaluminate liquid semi-product, the addition amount is 0.08% of the mass of the sodium metaaluminate liquid semi-product, so that Fe 3+ : 5ppm; sedimentation and filtration, and the sodium metaaluminate solution is obtained;

[0108] (6) modification

[0109] The filtered sodium metaaluminate solution of step (5) was cooled to 80°C, and PAM was added in an amount of 3% of the mass of the sodium metaaluminate solution, and stirred until dissolved, to obtain a purified water sodium metaaluminate solution.

[0110] Comparative Example 1

[0111] The same as Example 1, except that step (6) was omitted.

[0112] The products obtained in Examples 1-3 and Comparative Example 1 were subjected to performance testing of water purification effect, and the dosage was 3 parts per thousand of the mass of the wastewater, and the test results are shown in Tables 1-3.

[0113] Table 1 Performance testing results of water purification effect of coal chemical industry wastewater treated by Examples 1-3 and Comparative Example 1

[0114]

[0115] Table 2 Performance testing results of water purification effect of coal mining industry wastewater treated by Examples 1-3 and Comparative Example 1

[0116]

[0117] Table 3 Performance testing results of water purification effect of chemical industry fluorine wastewater treated by Examples 1-3 and Comparative Example 1

[0118]

Claims

1. A method for preparing sodium aluminate solution for water purification by recovering sodium aluminate solution from Raney nickel catalyst mother liquor, characterized in that, The Raney nickel catalyst mother liquor is composed of the following components by mass fraction: Sodium aluminate 25-30%; Water content 60-70%; Insoluble matter 5-10%; in: The mass fraction of Al2O3 is 10-13%, and the mass fraction of Na2O is 15-17%. The water contains impurity ions Cr 2+ >300ppm, impurity ion Fe 3+ >50ppm; The color of the Raney nickel catalyst mother liquor is 90-120 degrees; Includes the following steps: (1) Settlement The Raney nickel catalyst mother liquor was put into a container, pretreatment composite reagent was added, the temperature was raised, and sedimentation was carried out. (2) Filtration Cool to room temperature and filter; (3) Test indicators Detection of Cr 2+ Fe 3+ Whether the content and color are qualified, the qualification standard is: Cr 2+ <20ppm, Fe 3+ <10ppm, color <50 degrees; if unqualified, repeat steps (1) and (2); if qualified, proceed to step (4); (4) Concentration The qualified treatment liquid is pumped into the reaction vessel, stirring and heating are started, and the temperature is raised to 105-110℃. After concentration, the Al2O3 mass fraction content is >16% and the Na2O mass fraction content is >17.5%, thus obtaining sodium aluminate liquid semi-finished product. (5) Filtration Adding a mixture of composite cellulose and calcined diatomaceous earth to a liquid semi-finished product of sodium aluminate makes Fe... 3+ <8ppm; after sedimentation and filtration, sodium aluminate solution is obtained; (6) Modification Cool the sodium aluminate solution filtered in step (5), add the post-treatment modifier, and stir until dissolved to obtain sodium aluminate solution for water purification. The pretreatment compound agent mentioned in step (1) is a mixture of Na2S, H2O2, and CaCO3; The pretreatment composite agent is a mixture of Na2S, H2O2, and CaCO3 in a mass ratio of 1:(1-3):(0.5-2); The mass ratio of the composite cellulose and calcined diatomaceous earth in step (5) is (1-3):(1-2); The amount of the mixture of composite cellulose and calcined diatomaceous earth added in step (5) is three to eight ten-thousandths of the mass of sodium aluminate liquid semi-finished product. The cooling temperature described in step (6) is 60-80℃; The post-treatment modifying agent mentioned in step (6) is PAM.

2. The method for preparing sodium aluminate solution for water purification from Raney nickel catalyst mother liquor according to claim 1, characterized in that, The amount of the pretreatment composite agent added in step (1) is one to five ten-thousandths of the mass of the Raney nickel catalyst mother liquor.

3. The method for preparing sodium aluminate solution for water purification from Raney nickel catalyst mother liquor according to claim 1, characterized in that, The heating in step (1) is to raise the temperature to 60-70℃ and the settling time is 15-30 minutes.

4. The method for preparing sodium aluminate solution for water purification from Raney nickel catalyst mother liquor according to claim 1, characterized in that, The amount of post-treatment modifying agent added in step (6) is 1-3% of the mass of sodium aluminate solution.

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