CN112390232B - Method for recovering zinc selenite - Google Patents
Method for recovering zinc selenite Download PDFInfo
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- CN112390232B CN112390232B CN202011363788.4A CN202011363788A CN112390232B CN 112390232 B CN112390232 B CN 112390232B CN 202011363788 A CN202011363788 A CN 202011363788A CN 112390232 B CN112390232 B CN 112390232B
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B19/00—Selenium; Tellurium; Compounds thereof
- C01B19/004—Oxides; Hydroxides
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G9/00—Compounds of zinc
- C01G9/06—Sulfates
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
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Abstract
The present disclosure provides a method for recovering zinc selenite, which comprises the steps of: the method comprises the following steps: uniformly stirring and mixing the zinc selenite defective products, water and sulfuric acid to form a mixture containing selenious acid; step two: loading the mixture containing selenious acid into a selenium dioxide calcining furnace; step three: closing the selenium dioxide calcining furnace, heating the selenium dioxide calcining furnace to 300-450 ℃, introducing air, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air; step four: the selenium dioxide calcining furnace is heated to 460 ℃ to 670 ℃ again for calcining; step five: after the reaction is finished, cooling the selenium dioxide calcining furnace to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in the selenium dioxide calcining furnace. In the method, selenium and zinc in the zinc selenite defective products are recovered in the forms of selenium dioxide and zinc sulfate, so that comprehensive utilization of resources is facilitated, production cost is reduced, and environmental pollution is prevented and treated.
Description
Technical Field
The disclosure relates to the field of metallurgy and chemistry, in particular to a method for recovering zinc selenite.
Background
Zinc selenite is widely used as a decoloring agent and a coloring agent in the fields of glass, ceramics and the like. A certain amount of inferior products are generated during the process. The recovery of selenium and zinc in the zinc selenite substandard product has very important significance for comprehensive utilization of resources, reduction of production cost and prevention and treatment of environmental pollution.
Disclosure of Invention
In view of the problems in the prior art, the present disclosure aims to provide a method for recovering zinc selenite, which can recover selenium and zinc from inferior zinc selenite products, thereby facilitating comprehensive utilization of resources, reducing production cost and preventing and treating environmental pollution.
In order to achieve the above object, the present disclosure provides a method for recovering zinc selenite, comprising the steps of: the method comprises the following steps: stirring and mixing the zinc selenite defective products, water and sulfuric acid uniformly, and reacting to form a mixture containing selenious acid; step two: loading the mixture containing selenious acid into a selenium dioxide calcining furnace; step three: closing the selenium dioxide furnace, heating the selenium dioxide calcining furnace to 300-450 ℃, introducing air, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air; step four: the selenium dioxide calcinator is heated to 460-670 ℃ again for calcinations; step five: after the reaction is finished, cooling the selenium dioxide calcining furnace to be below 100 ℃, stopping introducing air, collecting the selenium dioxide in a product tank, and collecting zinc sulfate in the selenium dioxide calcining furnace.
In some embodiments, in the first step, the sulfuric acid is 95% -98% sulfuric acid, and the defective zinc selenite is sulfuric acid with water 1 (0.6-0.65) and water (0.15-0.2) by weight.
In some embodiments, in step three, the selenium dioxide calciner is warmed to 320 ℃ to 400 ℃.
In some embodiments, in the third step, the flow rate of the introduced air is 80L/min to 160L/min.
In some embodiments, in step four, the selenium dioxide calciner is again warmed to 500 ℃ to 670 ℃.
In some embodiments, in step four, the calcination time is from 20h to 48 h.
In some embodiments, in step five, after the reaction is completed, the selenium dioxide furnace temperature is set to 0 ℃ to 20 ℃.
In some embodiments, the mixture containing selenious acid is in the form of a mud.
The beneficial effects of this disclosure are as follows: the method recovers selenium and zinc in the zinc selenite defective products in the forms of selenium dioxide and zinc sulfate, thereby being beneficial to comprehensive utilization of resources, reducing production cost and preventing and controlling environmental pollution.
Detailed Description
The method for recovering zinc selenite according to the present disclosure is explained in detail as follows.
The recovery method of zinc selenite according to the present disclosure comprises the steps of: the method comprises the following steps: stirring and mixing the zinc selenite defective products, water and sulfuric acid uniformly, and reacting to form a mixture containing selenious acid; step two: loading the mixture containing selenious acid into a selenium dioxide calcining furnace; step three: closing the selenium dioxide calcining furnace, heating the selenium dioxide calcining furnace to 300-450 ℃, introducing air, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air; step four: the selenium dioxide calcining furnace is heated to 460 ℃ to 670 ℃ again for calcining; step five: after the reaction is finished, cooling the selenium dioxide calcining furnace to be below 100 ℃, stopping introducing air, collecting the selenium dioxide in a product tank, and collecting zinc sulfate in the selenium dioxide calcining furnace.
In some embodiments, the mixture containing selenious acid is in the form of a mud.
In the first step, the zinc selenite defective products, water and sulfuric acid are stirred and mixed uniformly and react to form a mixture containing selenic acid, and the reaction principle is as follows:
ZnSeO3+H2SO4→H2SeO3+ZnSO4
in the first step, because the decomposition temperature of the zinc selenite is very high, the efficiency is low by adopting a direct calcining mode, sufficient sulfuric acid is firstly added and fully mixed with the zinc selenite, and then the mixture is converted into the selenite with lower decomposition temperature, thereby being beneficial to reducing the temperature in the selenium dioxide calcining furnace in the later stage.
In some embodiments, in the first step, the sulfuric acid is 95% -98% sulfuric acid, and the defective zinc selenite is sulfuric acid with water 1 (0.6-0.65) and water (0.15-0.2) by weight. When the weight of the sulfuric acid is less than 0.6 time of that of the zinc selenite, the zinc selenite cannot be completely converted into the selenite, and the recovery rate of the selenium dioxide is reduced; when the amount of sulfuric acid is too much, the sulfuric acid is wasted. The amount of water is in the range, which is beneficial to uniformly mixing the zinc selenite and the sulfuric acid. Under the condition of the same amount of sulfuric acid, when the concentration of the sulfuric acid is lower than 95%, the sulfuric acid and the zinc selenite defective products do not completely react, and the recovery rate of selenium is reduced.
In the third step, the selenium dioxide calcining furnace is heated to the set temperature of 300-450 ℃, and the selenious acid is decomposed at the temperature to generate selenium dioxide and water.
The reaction principle involved in step three:
H2SeO3→SeO2↑+2H2O
in the third step, when the set temperature is 300-450 ℃, a valve of the selenium dioxide calcining furnace is opened to introduce air, the generated selenium dioxide is brought into a product tank communicated with the selenium dioxide calcining furnace by the air, and the selenium dioxide generated by reaction is introduced into the air to accelerate the rate of the selenium dioxide entering the product tank.
In some embodiments, in step three, the selenium dioxide calciner is heated to the set temperature of 320 ℃ to 400 ℃. The temperature in the range can better perform the reaction of converting selenious acid into selenium dioxide and reacting with water.
In some embodiments, in step three, the flow rate of the introduced air is 80L/min to 160L/min. The air flow is in the range, the speed of the selenium dioxide entering the product tank can be accelerated, the pressure of the selenium dioxide calcining furnace is reduced, and the recovery rate of the selenium dioxide is ensured.
In the fourth step, the selenium dioxide calcining furnace is heated to the set temperature of 460 ℃ to 670 ℃ again for calcining. H2SeO3→SeO2↑+2H2O is an endothermic reaction, increasing the temperature reaction equilibrium moves to the right, so increasing the temperature at this point can shift the reaction equilibrium to the right, enhancing the reaction to take place.
In some embodiments, in step four, the selenium dioxide calciner is again warmed to the set temperature of 500 ℃ to 670 ℃. Within the temperature range, the reaction is carried out more thoroughly, i.e. the yield of the selenium dioxide can be improved.
In some embodiments, in step four, the calcination time is from 20h to 48 h.
In some embodiments, in step five, after the reaction is completed, the selenium dioxide calciner temperature is set to 0 ℃ to 20 ℃. Based on setting the temperature to be far below 100 ℃, the selenium dioxide furnace can be cooled to below 100 ℃ at this moment, when waiting that the selenium dioxide furnace falls to below 100 ℃, collect the product, if the temperature is too high, can have certain potential safety hazard to the personnel of collecting the product. The selenium dioxide furnace can adopt the structure of Chinese patent application publication No. CN101112976A published in 2008, 1, 30.
In the recovery method of the zinc selenite, the selenium and the zinc in the inferior zinc selenite are recovered in the forms of the selenium dioxide and the zinc sulfate, which has very important significance for comprehensive utilization of resources, reduction of production cost and prevention and control of environmental pollution, in particular, the selenium dioxide is a catalyst for producing electrolytic manganese and is a production raw material for producing selenium compounds, the selenium compounds are widely used as decolorants, colorants, feed additives and the like of glass, the zinc sulfate is a main raw material for producing lithopone and zinc salts, can also be used as a printing and dyeing mordant, a preservative of wood and leather, and is also an important auxiliary raw material for producing viscose fibers and vinylon fibers, and in addition, the zinc dioxide also has application in the electroplating and electrolysis industries and can also be used for producing cables. In addition, in the recovery method of zinc selenite disclosed by the invention, no harmful gas is generated.
Finally, a test process is given.
Example 1
The method comprises the following steps: mixing and stirring evenly 50kg of zinc selenite defective products containing 41.05% of selenium and 34% of zinc, 10kg of water and 30kg of 98% of sulfuric acid, and reacting to form mixed mud containing selenious acid;
step two: loading the mixed mud containing selenious acid into a selenium dioxide calcining furnace;
step three: closing the selenium dioxide furnace, heating the selenium dioxide calcining furnace to 300 ℃, introducing air at the flow rate of 80L/min, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air;
step four: the selenium dioxide calcining furnace is heated to 500 ℃ again and is calcined for 20 hours;
step five: after the reaction is finished, setting the temperature to be 0 ℃, naturally cooling to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in a selenium dioxide calcining furnace, wherein the weight of the material in the selenium dioxide calcining furnace is 42kg, the weight of selenium accounts for 0.8101% of the weight of the residual material after calcining, the weight of zinc accounts for 40.3% of the weight of the residual material after calcining, the selenium recovery rate is 98.3%, and the zinc recovery rate is 99.6%. (selenium recovery rate 1-the amount of selenium remaining in the calciner/the amount of selenium in the raw material; zinc recovery rate 1-the amount of zinc remaining in the calciner/the amount of zinc in the raw material).
Example 2
The method comprises the following steps: mixing and stirring evenly 50kg of zinc selenite defective products containing selenium 41.05% and zinc 34%, 8.5kg of water and 31kg of 98% sulfuric acid, and reacting to form mixed mud containing selenious acid;
step two: loading the mixed mud containing selenious acid into a selenium dioxide calcining furnace;
step three: closing the selenium dioxide furnace, heating the selenium dioxide calcining furnace to 350 ℃, introducing air at the flow rate of 120L/min, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air;
step four: the selenium dioxide calcining furnace is heated to 600 ℃ again and calcined for 35 hours;
step five: after the reaction is finished, setting the temperature to be 0 ℃, naturally cooling to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in a selenium dioxide calcining furnace, wherein the weight of the material in the selenium dioxide calcining furnace is 42.1kg, the weight of selenium accounts for 0.7649% of the weight of the residual material after calcining, the weight of zinc accounts for 40.2% of the weight of the residual material after calcining, the selenium recovery rate is 98.4%, and the zinc recovery rate is 99.6%.
Example 3
The method comprises the following steps: mixing and stirring evenly 50kg of defective zinc selenite containing 41.05% of selenium and 34% of zinc, 7.5kg of water and 32.5kg of 98% sulfuric acid, and reacting to form mixed mud containing selenious acid;
step two: loading the mixed mud containing selenious acid into a selenium dioxide calcining furnace;
step three: closing the selenium dioxide furnace, heating the selenium dioxide calcining furnace to 350 ℃, introducing air at the flow rate of 160L/min, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air;
step four: the selenium dioxide calcining furnace is heated to 670 ℃ again and is calcined for 48 hours;
step five: after the reaction is finished, setting the temperature to be 0 ℃, naturally cooling to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in a selenium dioxide calcining furnace, wherein the weight of the materials in the selenium dioxide calcining furnace is 41.9kg, the weight of selenium accounts for 0.5651% of the weight of the residual materials after calcining, the weight of zinc accounts for 40.4% of the weight of the residual materials after calcining, the selenium recovery rate is 98.8%, and the zinc recovery rate is 99.6%.
Comparative example 1
The method comprises the following steps: mixing and stirring evenly 50kg of zinc selenite defective products containing selenium 41.05% and zinc 34%, 15kg of water and 25kg of 98% sulfuric acid, and reacting to form mixed mud containing selenious acid;
step two: loading the mixed mud containing selenious acid into a selenium dioxide calcining furnace;
step three: closing the selenium dioxide furnace, heating the selenium dioxide calcining furnace to 350 ℃, introducing air at the flow rate of 160L/min, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air;
step four: the selenium dioxide calcining furnace is heated to 670 ℃ again and is calcined for 48 hours;
step five: after the reaction is finished, setting the temperature to be 0 ℃, naturally cooling to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in a selenium dioxide calcining furnace, wherein the weight of the materials in the selenium dioxide calcining furnace is 44.5kg, the weight of selenium accounts for 4.8% of the weight of the residual materials after calcining, the weight of zinc accounts for 38.0% of the weight of the residual materials after calcining, the selenium recovery rate is 89.6%, and the zinc recovery rate is 99.5%.
Comparative example 2
The procedure of comparative example 1 was repeated except that the sulfuric acid used in step one was 94% sulfuric acid.
The weight of the materials in the selenium dioxide calcining furnace is 45.2kg, the weight of selenium accounts for 5.8 percent of the weight of the residual materials after calcining, the weight of zinc accounts for 37.4 percent of the weight of the residual materials after calcining, the recovery rate of selenium is 87.2 percent, and the recovery rate of zinc is 99.4 percent.
As can be seen from examples 1-3 and comparative example 1: when the addition amount of the sulfuric acid is insufficient, the selenium recovery rate is low, and the zinc sulfate content is impure; as can be seen from comparative examples 1-2: when the concentration of sulfuric acid is reduced, the selenium recovery rate is further lower and the zinc sulfate content is less pure.
The above-disclosed features are not intended to limit the scope of practice of the present disclosure, and therefore, all equivalent variations that are described in the claims of the present disclosure are intended to be included within the scope of the claims of the present disclosure.
Claims (7)
1. A method for recovering zinc selenite is characterized by comprising the following steps:
the method comprises the following steps: stirring and mixing the zinc selenite defective products, water and sulfuric acid uniformly and reacting to form a mixture containing selenic acid;
step two: loading the mixture containing selenious acid into a selenium dioxide calcining furnace;
step three: closing the selenium dioxide calcining furnace, heating the selenium dioxide calcining furnace to 300-450 ℃, introducing air, and bringing the generated selenium dioxide into a product tank communicated with the selenium dioxide calcining furnace by the air;
step four: the selenium dioxide calcining furnace is heated to 460 ℃ to 670 ℃ again for calcining;
step five: after the reaction is finished, cooling the selenium dioxide calcining furnace to be below 100 ℃, stopping introducing air, collecting selenium dioxide in a product tank, and collecting zinc sulfate in the selenium dioxide calcining furnace;
in the first step, the sulfuric acid is 95-98% sulfuric acid, and the defective zinc selenite is sulfuric acid, namely water =1 (0.6-0.65) and (0.15-0.2) by weight.
2. The method for recovering zinc selenite as set forth in claim 1, wherein the temperature of the selenium dioxide calcining furnace is raised to 320-400 ℃ in the third step.
3. The method for recovering zinc selenite according to claim 1, wherein the flow rate of the air introduced in the third step is 80 to 160L/min.
4. The method for recovering zinc selenite as set forth in claim 1, wherein the calcinator for selenium dioxide is further heated to 500-670 ℃ in the fourth step.
5. The method for recovering zinc selenite according to claim 1, wherein the calcination time in step four is 20 to 48 hours.
6. The method for recovering zinc selenite as claimed in claim 1, wherein in the fifth step, after the reaction is completed, the temperature of the selenium dioxide furnace is set to 0-20 ℃.
7. The method for recovering zinc selenite as claimed in claim 1, wherein the mixture containing selenite is in the form of a sludge.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011363788.4A CN112390232B (en) | 2020-11-27 | 2020-11-27 | Method for recovering zinc selenite |
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| CN202011363788.4A CN112390232B (en) | 2020-11-27 | 2020-11-27 | Method for recovering zinc selenite |
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| CN112390232B true CN112390232B (en) | 2022-06-17 |
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Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB808637A (en) * | 1955-08-09 | 1959-02-11 | Diamond Alkali Co | Improvements in or relating to the recovery of selenium |
| GB919872A (en) * | 1960-09-08 | 1963-02-27 | Asahi Chemical Ind | A method for recovery of selenium from a selenium or its compounds-enriched solution |
| CN101112976B (en) * | 2007-06-29 | 2010-12-01 | 清远先导稀有材料有限公司 | Process and equipment for producing selenium dioxide |
| CN102491287B (en) * | 2011-12-11 | 2014-03-26 | 郴州市金贵银业股份有限公司 | Process for separating and recovering selenium from selenium-containing material |
| CN105543485B (en) * | 2016-03-07 | 2017-09-29 | 曹明华 | A kind of method that valuable metal is separated and recovered from copper anode mud |
| CN106379870A (en) * | 2016-08-25 | 2017-02-08 | 浙江亚栋实业有限公司 | Method for recovery of selenium from copper anode mud |
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