CN109112561B - Method for prolonging shelf life of stannous sulfate - Google Patents
Method for prolonging shelf life of stannous sulfate Download PDFInfo
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Abstract
A method of extending the shelf life of stannous sulfate comprising the steps of: preparing an electrolytic acid solution: adding boric acid to the sulfuric acid solution; and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic bath to carry out electrolytic reaction with a refined tin polar plate; adding an antioxidant: sequentially adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished, and uniformly mixing; and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product. The invention avoids the risk of partial crystal oxidation when the crystal is broken, and also avoids the problem of oxidation resistance reduction of the surface coating falling product.
Description
Technical Field
The invention belongs to the field of stannous sulfate preparation, and particularly relates to a method for prolonging the quality guarantee period of stannous sulfate.
Background
The stannous sulfate is white or light yellow crystalline powder. Can be dissolved in water and dilute sulphuric acid, the water solution is rapidly decomposed, the water solution starts to be decomposed into basic salt at the temperature of more than 360 ℃, and the basic salt is slowly oxidized in the air and becomes yellowish. The method is mainly used for tin plating in the electroplating industry, oxidation coloring of the surface of aluminum alloy, mordant in the printing and dyeing industry, hydrogen peroxide remover and the like. And can be used for plating tin or chemical reagents, such as alloy, tinplate, cylinder piston, steel wire, etc. by acid electroplating, and for bright plating of electronic devices. In addition, the aluminum alloy surface treatment agent is also used for oxidation coloring of aluminum alloy product coatings, and is used as a mordant in printing and dyeing industry, a hydrogen peroxide remover in organic solution and the like.
At present, the method for producing stannous sulfate mainly comprises the following steps: the method comprises the following steps of electrolyzing a tin plate in a sulfuric acid solvent, or obtaining a stannous sulfate product by concentrating after directly reacting tin powder with sulfuric acid to obtain a stannous sulfate solution, wherein the problems in the prior art are as follows: when the stannous sulfate product crystals are stored in the air, bivalent tin in the stannous sulfate product crystals is easily oxidized into tetravalent tin, so that the turbidity of the product is increased, and the shelf life of the product is shortened.
Regarding the process for producing stannous sulfate, we have looked to the following relevant literature:
1. patent application No.: CN95205040, inventive name: the device for producing stannous sulfate by electrolysis comprises the following processes: the utility model relates to a device of electrolysis production stannous sulfate, it has an electrolysis trough, utilizes ion exchange membrane as the diaphragm in the electrolysis trough to adopt the multielectrode to make electrolysis trough form a plurality of anode compartments and cathode chamber, the anode plate is pure tin, and sulphuric acid solution generates stannous sulfate at the anode compartment after the electrolysis. Because the anion exchange membrane is utilized, the generation of sponge tin on the cathode is eliminated, and the quality and the quantity of products are improved. The current efficiency and the production benefit are improved, the cost is reduced, the management and the operation are easy, and the stability of the product quality is maintained. However, the disadvantage of this invention is that the resulting product crystals are subjected to air oxidation during drying and storage.
2. Preparing high-purity stannous sulfate by a Crqing ion diaphragm electrolysis method, university of Wuyi student newspaper: nature science edition 2000,14(1): 55-59; the method adopts an anion diaphragm electrolysis method to prepare stannous sulfate, effectively prevents the precipitation of cathode sponge tin, and greatly improves the current efficiency of the anode. The best condition of the process is found through experiments, so that Sn is obtained2+Oxidation to Sn4+The tendency of (c) is minimized and the possibility of anode oxygen evolution is prevented. The anode current density is l0mA cm-2The anodic sulfuric acid concentration is 1.0 mol. L-1The cathode sulfuric acid concentration is about 1.2 mol. L-1Anode region Sn2+The content is controlled to be lower than l00g & L-1The acidity of mother liquor during evaporation should be less than 8mol · L-1SnSO prepared by the process4The product has purity up to 99.9% after analysis, all indexes reach the analytical grade standard, and the efficiency is up to 99.5%. However, the stannous sulfate prepared by the method has high purity, but the oxidation condition of the stannous sulfate cannot be well protected in the process, and the shelf life of the product is short.
3. The patent No. Z L201410846701.7 discloses a method for prolonging the shelf life of a stannous sulfate product, which comprises the following steps of (1) washing, namely, after concentrating and crystallizing a stannous sulfate solution and carrying out solid-liquid separation, washing stannous sulfate crystals for 5-10 min by using an ethanol solution, then carrying out centrifugal separation and drying, (2) coating, namely, after drying is stopped, uniformly spraying a hydroquinone solution with the mass content of 0.1-0.3% onto the stannous sulfate crystals, stirring for 10-20 min, then uniformly spraying a β -naphthol solution with the mass content of 0.1-0.3%, stirring for 5-8 min, finally uniformly spraying a benzotriazole solution with the mass content of 0.05-0.1%, and fully stirring for 10-20 min.
Disclosure of Invention
The invention aims to solve the technical problems and provide a method for prolonging the quality guarantee period of a stannous sulfate product, which can avoid the condition that an envelope falls off and does not influence the purity of the product.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a method of extending the shelf life of stannous sulfate comprising the steps of:
(1) preparing an electrolytic acid solution: adding boric acid to the sulfuric acid solution;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic bath to carry out electrolytic reaction with a refined tin polar plate;
(3) adding an antioxidant: sequentially adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished, and uniformly mixing;
(4) and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product.
As a further technical scheme, the concentration of the sulfuric acid solution is 15-25 g/L.
As a further technical proposal, the concentration of the boric acid after being added is 1 to 3 g/L.
According to a further technical scheme, the pyrogallic acid is added at a concentration of 0.1-0.2 g/L, the hydroquinone is added at a concentration of 0.05-0.08 g/L, and the ascorbic acid is added at a concentration of 0.02-0.05 g/L.
As a further technical scheme, the voltage of the electrolytic bath is 1.8V-2.2V, and the electrolytic reaction time is 18-20 h.
As a further technical scheme, the drying temperature is 60-90 ℃, and the drying is carried out until the fluidity of the product reaches the first-class standard.
The electrolytic reaction in the invention adopts the ion membrane electrolysis method commonly used in the field, and the mentioned sedimentation, concentration crystallization, solid-liquid separation and drying are also conventional means in the field, so detailed description is not given.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention uses sulfuric acid and refined tin as raw materials, adopts an ion-exchange membrane electrolysis process, and reduces Sn generated in the electrolysis process by adding boric acid before the reaction4+(ii) a The antioxidant is added into the stannous sulfate solution after reaction immediately, and then the mixture is subjected to precipitation and concentration crystallization, so that the antioxidant is not only on the surface but also uniformly mixed in the stannous sulfate crystal, thereby avoiding the risk of oxidation of local crystals when the crystal is broken, and simultaneously avoiding the problem of oxidation resistance reduction of surface coating falling products.
2. The invention does not affect the purity of the product. According to the concentration of 4m of solution in each tank3According to the method, the quality of the product is 450kg, the input amount of the antioxidant is 0.6-1.32 kg, the antioxidant accounts for less than 0.3% of the content of the product, the purity of the obtained stannous sulfate finished product is over 99.2%, other indexes meet the national standard of stannous sulfate, the quality of the product is not affected, the purpose of prolonging the quality guarantee period of the product is achieved, and the quality guarantee period of the product is 9-10.5 months.
Detailed Description
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited to the scope of the examples.
The materials involved in the examples are all commercially available.
Example 1:
a method of extending the shelf life of stannous sulfate comprising the steps of:
(1) preparing an electrolytic acid solution, namely adding boric acid into a sulfuric acid solution, wherein the concentration of the sulfuric acid solution is 15 g/L, and the concentration of the added boric acid is 1 g/L;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic cell to carry out electrolytic reaction with the refined tin polar plate, wherein the voltage of the electrolytic cell is 1.8V, and the electrolytic reaction time is 20 h;
(3) adding an antioxidant, namely adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished in sequence, and uniformly mixing, wherein the concentration of the pyrogallic acid after the addition is 0.1 g/L, the concentration of the hydroquinone after the addition is 0.05 g/L, and the concentration of the ascorbic acid after the addition is 0.02 g/L;
(4) and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product.
Example 2:
a method of extending the shelf life of stannous sulfate comprising the steps of:
(1) preparing an electrolytic acid solution, namely adding boric acid into a sulfuric acid solution, wherein the concentration of the sulfuric acid solution is 18 g/L, and the concentration of the added boric acid is 1.5 g/L;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic cell to carry out electrolytic reaction with the refined tin polar plate, wherein the voltage of the electrolytic cell is 1.9V, and the electrolytic reaction time is 20 h;
(3) adding an antioxidant, namely sequentially adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished, and uniformly mixing, wherein the concentration of the pyrogallic acid after the addition is 0.1 g/L, the concentration of the hydroquinone after the addition is 0.06 g/L, and the concentration of the ascorbic acid after the addition is 0.03 g/L;
(4) and (3) carrying out sedimentation, concentration and crystallization, solid-liquid separation and drying on the uniformly mixed reaction solution as in example 1 to obtain a stannous sulfate product.
Example 3:
a method of extending the shelf life of stannous sulfate comprising the steps of:
(1) preparing an electrolytic acid solution, namely adding boric acid into a sulfuric acid solution, wherein the concentration of the sulfuric acid solution is 20 g/L, and the concentration of the added boric acid is 2 g/L;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic cell to carry out electrolytic reaction with the refined tin polar plate, wherein the voltage of the electrolytic cell is 2.0V, and the electrolytic reaction time is 19 h;
(3) adding an antioxidant, namely sequentially adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished, and uniformly mixing, wherein the concentration of the pyrogallic acid after the addition is 0.2 g/L, the concentration of the hydroquinone after the addition is 0.07 g/L, and the concentration of the ascorbic acid after the addition is 0.04 g/L;
(4) and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product.
Example 4:
a method of extending the shelf life of stannous sulfate comprising the steps of:
(1) preparing an electrolytic acid solution, namely adding boric acid into a sulfuric acid solution, wherein the concentration of the sulfuric acid solution is 25 g/L, and the concentration of the added boric acid is 3 g/L;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic cell to carry out electrolytic reaction with the refined tin polar plate, wherein the voltage of the electrolytic cell is 2.2V, and the electrolytic reaction time is 18 h;
(3) adding an antioxidant, namely adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished in sequence, and uniformly mixing, wherein the concentration of the pyrogallic acid after the addition is 0.2 g/L, the concentration of the hydroquinone after the addition is 0.08 g/L, and the concentration of the ascorbic acid after the addition is 0.05 g/L;
(4) and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product.
The product specifications for examples 1-4 are shown in Table 1:
TABLE 1
As can be seen from Table 1, the quality of the stannous sulfate product is not affected by the method for prolonging the shelf life of the product, and the quality reaches the national standard (GB/T23839-2009). And the shelf life exceeds the 5-month maximum shelf life before adding.
Single factor contrast experiment
The other steps were carried out as in example 3 by adding the following antioxidants to step (3):
(A) no antioxidant was added;
(B) 0.31 g/L g of pyrogallic acid is added;
(C) adding 0.31 g/L of hydroquinone;
(D) adding 0.31 g/L of ascorbic acid;
(E) β -naphthol 0.31 g/L was added;
(F) adding 0.31 g/L of benzotriazole;
(G) adding 0.31 g/L of hydrazine hydrate;
(H) adding 0.31 g/L of catechol;
(I) 0.15 g/L g of pyrogallic acid and 0.16 g/L g of hydroquinone are added;
(J) 0.15 g/L g of pyrogallic acid and 0.16 g/L g of ascorbic acid are added;
(K) adding 0.16 g/L g of hydroquinone and 0.15 g/L g of ascorbic acid;
(L) adding hydrazine hydrate 0.15 g/L and catechol 0.16 g/L;
(M) adding 0.07 g/L g of hydroquinone, 0.2 g/L g of β -naphthol and 0.04 g/L g of benzotriazole;
(N) 0.2 g/L g of pyrogallic acid, 0.07 g/L g of hydroquinone and 0.04 g/L g of ascorbic acid are added.
The stannous sulfate crystals treated by the steps are detected, and the experimental results are shown in table 2:
TABLE 2
| Comparative experiment | Shelf life |
| A | 4 months old |
| B | 7 months old |
| C | 6 months old |
| D | 6.5 months |
| E | 5.5 months |
| F | 6 months old |
| G | For 5 months |
| H | 6 months old |
| I | 7.5 months |
| J | 7.2 months |
| K | 7.2 months |
| L | 6 months old |
| M | 7.5 months |
| N | 10.5 months |
As can be seen from Table 2:
(1) the antioxidant of the present invention extended the shelf life of the product by 6.5 months compared to a product without added antioxidant.
(2) Compared with a single antioxidant, the compound antioxidant provided by the invention has a longer shelf life.
(3) Compared with other compound antioxidants, the compound antioxidant disclosed by the invention has the advantage that the shelf life of the product is longer.
The above-described embodiments are only specific examples for further explaining the object, technical solution and advantageous effects of the present invention in detail, and the present invention is not limited thereto. Any modification, equivalent replacement, improvement and the like made within the scope of the present disclosure are included in the protection scope of the present invention.
Claims (4)
1. A method for prolonging the shelf life of stannous sulfate is characterized in that: the method comprises the following steps:
(1) preparing an electrolytic acid solution: adding boric acid to the sulfuric acid solution;
(2) and (3) electrolytic reaction: putting the prepared electrolytic acid solution into an electrolytic bath to carry out electrolytic reaction with a refined tin polar plate;
(3) adding an antioxidant, namely sequentially adding pyrogallic acid, hydroquinone and ascorbic acid into the solution after the reaction is finished, and uniformly mixing, wherein the concentration of the pyrogallic acid after the addition is 0.1-0.2 g/L, the concentration of the hydroquinone after the addition is 0.05-0.08 g/L, and the concentration of the ascorbic acid after the addition is 0.02-0.05 g/L;
(4) and settling, concentrating and crystallizing the uniformly mixed reaction liquid, carrying out solid-liquid separation, and drying to obtain a stannous sulfate product.
2. The method for prolonging the shelf life of stannous sulfate according to claim 1, wherein the concentration of the sulfuric acid solution is 15-25 g/L.
3. The method for prolonging the shelf life of stannous sulfate according to claim 1, wherein the concentration of the added boric acid is 1-3 g/L.
4. The method of claim 1, wherein the shelf life of the stannous sulfate is extended by: the voltage of the electrolytic bath is 1.8V-2.2V, and the electrolytic reaction time is 18-20 h.
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| CN112941574A (en) * | 2021-01-27 | 2021-06-11 | 许继电源有限公司 | Method for tin plating of external welding grounding copper conductor of cabinet |
| CN113880129A (en) * | 2021-11-17 | 2022-01-04 | 云南锡业锡化工材料有限责任公司 | Method for preparing large-particle low-dissolution-turbidity stannous sulfate |
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- 2018-09-25 CN CN201811115352.6A patent/CN109112561B/en active Active
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| JPS57200221A (en) * | 1981-06-05 | 1982-12-08 | Mitsubishi Metal Corp | Method for preventing hydrolysis of tin salt in acidic solution of tin salt |
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| CN104591266A (en) * | 2014-12-31 | 2015-05-06 | 柳州华锡铟锡材料有限公司 | Method for prolonging expiration date of stannous sulfate product |
| CN207276733U (en) * | 2017-10-19 | 2018-04-27 | 精细化学品集团有限公司 | It is used to prepare the ion-exchange membrane electrolyzer of stannous sulfate |
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