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Method for preparing hypophosphorous acid by using electrolytic method

A hypophosphorous acid and electrolysis technology, applied in the direction of electrolysis process, electrolysis components, etc., can solve the problems of large-scale industrial production restrictions, expensive precious metal electrodes, etc., and achieve the effects of easy large-scale industrial production, low price, and simple process.

Inactive Publication Date: 2002-03-27
NANKAI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In addition, noble metal electrodes are expensive, limiting large-scale industrial production

Method used

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  • Method for preparing hypophosphorous acid by using electrolytic method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The anode material is graphite, and the electrode area is 40cm 2 , The cathode is a stainless steel electrode. Anion and cation exchange membranes were purchased from Shanghai Chemical Plant, and the membrane area used in electrolysis was 48cm 2 . The solution volume of each chamber of the six-chamber electrodialysis cell is 500ml. The initial solution of the anode chamber before electrolysis is 10g / L sulfuric acid, the raw material chamber is 500g / L sodium hypophosphite, the cathode chamber and its adjacent buffer chamber are both 10g / L sodium hydroxide, and the product chamber and its adjacent buffer chamber are both 10g / L hypophosphorous acid.

[0019] Under the conditions of working voltage of 10-15V and holding current of 3.0A, after continuous electrolysis for 6 hours, the concentration of hypophosphorous acid in the product chamber is 69.3g / L, and the calculated current efficiency at this time is 80.9%.

[0020] After 6H electrolysis under different current c...

Embodiment 2

[0029] The initial working conditions of the six-chamber electrodialysis cell are the same as in Example 1.

[0030] When the working current is 3A, the electrolysis time is 30H, the concentration of hypophosphorous acid in the product chamber is 178.6g / L, and the current efficiency is 55.3%.

[0031] The concentrations of the hypophosphorous acid solution in the product chamber obtained under different electrolysis times are shown in Table 2.

[0032] Table 2 Product concentration and current efficiency under different electrolysis time

[0033] Electrolysis time (H) Hypophosphorous acid concentration (g / L) Current efficiency (%)

[0034] 6 69.3 80.9

[0035] 12 101.9 77.4

[0036] 18 136.1 68.3

[0037] 24 169.1 60.5

[0038] 30 178.6 55.3

Embodiment 3

[0040] The initial working conditions of the six-chamber electrodialysis cell are the same as in Example 1.

[0041] When the working current is 3A, the electrolysis time is 30H, and the contents of sodium ion and sulfate ion in the product chamber are 50ug / L and 0.80g / L respectively.

[0042] The contents of sodium ions and sulfate ions in the product compartment obtained under different electrolysis times are shown in Table 3.

[0043] Table 3 Changes of sodium ion and sulfate ion content in hypophosphorous acid products with time

[0044] Electrolysis time (H) Sodium ion content (ug / L) Sulfate content (g / L)

[0045] 6 5 0.11

[0046] 12 13 0.36

[0047] 18 25 0.48

[0048] 24 40 0.76

[0049] 30 50 0.80

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Abstract

The method for preparing hypophosphorous acid by using electrolysis method is characterized by that it uses the alkali metal hypophosphite as raw material, uses graphite as anode, uses stainless steel as cathode and uses the mehtod of electrolyzing water by utilizing electrolysis bath to make electrolysis, in which the raw material chamber possesses aqueous solution of sodium hypophosphite whose concentration is 300-500 g / L, the primary solution in anode chamber is sulfuric acid solution whose concentration is 5-15 g / L, the primary solution in the cathode chamber and its adjacent buffer chamber is an alkali solution whose concentration is 5-15 g / L, and the primary solution in the product chamber and its adjacent buffer chamber is the hypophosphorous acid solution whose concentration is 5-15 g / L. Said invention does not produce waste residue and waste liquid, and it is a clean production method.

Description

technical field [0001] The invention relates to the preparation of hypophosphorous acid, which is a method for preparing hypophosphorous acid by electrolysis. Background technique [0002] Hypophosphorous acid is one of the widely used phosphorus chemical products. The traditional preparation method is to react yellow phosphorus with barium hydroxide, and add sulfuric acid to remove barium. However, due to the low solubility of barium hypophosphite, the concentration of hypophosphorous acid produced is not high, and industrial products need to be recrystallized and purified many times, so that the application of this process is limited. In addition, an ion exchange resin method is used to prepare hypophosphorous acid, that is, sodium hypophosphite is used as a raw material, and a strong acid cation exchange resin is used to remove sodium to obtain a dilute acid solution [Arzoumanidis et al, US Patent, 4265866, 1981]. This kind of method is more l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25B1/22
Inventor 张宝贵张英喆程建忠万忠发万忠生
Owner NANKAI UNIV