Name | sodium hypophosphite hydrate |
Synonyms | Hypophosphite sodium phosphinate hydrate sodium hypophosphite hydrate SODIUM HYPOPHOSPHITE 1HYD XTL SODIUM HYPOPHOSPHITE-1-HYDRATE SODIUM PHOSPHINATE MONOHYDRATE PRE-STAINED PROTEIN MARKER BROAD Phosphinic acid, sodium salt, monohydrate SODIUM HYPOPHOSPHITE, MONOHYDRATE, REAGENTSODIUM HYPOPHOSPHITE, MONOHYDRATE, REAGENTSODIUM HYPOPHOSPHITE, MONOHYDRATE, REAGENTSODIUM HYPOPHOSPHITE, MONOHYDRATE, REAGENT |
CAS | 10039-56-2 123333-67-5 |
EINECS | 600-090-7 |
InChI | InChI=1/Na.H3O2P.H2O/c;1-3-2;/h;3H2,(H,1,2);1H2/q+1;;/p-1 |
InChIKey | ACUGTEHQOFWBES-UHFFFAOYSA-M |
Molecular Formula | H4NaO3P |
Molar Mass | 105.99 |
Density | 0.8 |
Melting Point | 90°C |
Water Solubility | 1000 g/L (20 ºC) |
Solubility | 1000 g/L (20°C) |
Appearance | Solid |
Color | Colorless crystalline |
Odor | Odorless |
Merck | 14,8629 |
PH | 6-8 (20℃, 5%) |
Storage Condition | Room Temprature |
Sensitive | Hygroscopic |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. |
WGK Germany | 3 |
RTECS | SZ5640000 |
FLUKA BRAND F CODES | 3 |
TSCA | Yes |
HS Code | 28351000 |
A colorless monoclinic crystal or a pearl-luster crystal or a white crystalline powder. The relative density was 1. 388. Odorless and salty. Soluble in water, ethanol, glycerol; Slightly soluble in ammonia, ammonia; Insoluble in ether. The aqueous solution is neutral, and the solubility in water at 100 ° C. Is 667g/10g water. Deliquescence. It is relatively stable when stored in a dry state, and rapidly decomposes when heated at a temperature exceeding 200 ° C., and releases a toxic phosphine capable of spontaneous combustion. When exposed to strong heat will be explosive, mixed with potassium chlorate or other oxidants will be explosive. Sodium hypophosphite is a strong reducing agent that reduces salts of gold, silver, mercury, nickel, chromium, cobalt, and the like to the metal state. Under normal pressure, heating and evaporating the sodium hypophosphite solution will cause explosion, so the evaporation should be carried out under reduced pressure.
double decomposition method: the yellow phosphorus and slaked lime and water in the reactor, at a temperature of 98 deg C reaction to produce calcium hypophosphite, the reaction process in the formation of phosphine, need to pay attention to safety protection. The unreacted material was removed by filtration, and then carbon dioxide was introduced to further remove a small amount of calcium hydroxide. The metathesis reaction was carried out by adding sodium carbonate solution to the calcium hypophosphite solution to form sodium hypophosphite. Calcium carbonate was removed by filtration, and when the filtrate was concentrated to about 200be by vacuum evaporation, calcium carbonate was removed by filtration, and the filtrate was concentrated for the second time until the liquid surface exhibited a crystalline membrane, and crystallized by cooling, the mother liquor was removed by centrifugal separation to prepare a sodium hypophosphite product. The mother liquor can be recycled.
used as a reducing agent for electroless nickel plating, used as a reducing agent in chemical industry and pharmaceutical industry. Raw materials for the preparation of other hypophosphates.
domestic products are packed with plastic woven bags lined with polyethylene plastic bags, each with a net weight of 40kg; Export products are packed with iron barrels lined with polyethylene plastic bags, each with a net weight of 50kg. Should be stored in a cool, ventilated, dry, clean warehouse. The package is sealed, protected from moisture, and protected from chlorate and other oxidants. Stay away from heat sources and fire types. They shall not be co-stored and co-transported with toxic substances and contaminated substances. Transport should be protected from rain and sun exposure. During loading and unloading, care should be taken to prevent package breakage. In case of fire, it can be suppressed by water, sand and all kinds of fire extinguishing.
pH indicator color change ph range | 6 - 8 at 50g/l at 25 c |
overview | sodium hypophosphite, also known as "sodium dihydrogen hypophosphite", "sodium hypophosphite", chemical formula NaH2PO2, colorless crystal or crystal or granular powder with pearl luster. Soluble in water, alcohol and glycerin, insoluble in ether. Easy deliquescence. It is relatively stable when stored in a dry state. When heated over 200°C, it will quickly decompose and release the spontaneous combustion toxic gas phosphine. When it encounters strong heat or mixed with oxidants such as potassium chlorate, it will cause an explosion. Sodium hypophosphite is an ideal reducing agent, mainly used in chemical plating, electroplating and organic synthesis industries. With the deepening of research and the large increase of its derivatives, its application field continues to expand and has become an important inorganic salt product. |
properties | sodium hypophosphite is colorless crystal or crystal or granular powder with pearl luster, odorless and salty taste; Specific gravity: 1.49; Relative density: 1.33; Melting point: 26.5 ℃; Soluble in water, ethanol, glycerin, slightly soluble in liquid ammonia and ammonia, insoluble in ether; In dry air, there is slight deliquescence in the wet air. Slowly decompose above 110 ℃, release phosphine and immediately catch fire in the air; decompose at 200 ℃ and lose crystal water; strong reducing agent can reduce the salts of gold, silver, platinum, mercury, nickel and other metals into a metal state; Strong heat or contact with potassium chlorate and other oxidants can cause explosion; toxicity is level 2, which is an actual non-toxic substance. |
Sodium hypophosphite | Sodium hypophosphite is also called "sodium dihydrogen hypophosphite" and "sodium hypophosphite". Chemical formula NaH2PO2 · H2O. Molecular weight 105.99. Colorless needle-like monoclinic crystal or white granular powder. It has a pearl luster. It tastes salty. Stroke in dry air and slight deliquescence in wet air. Soluble in water, ethanol, soluble in glycerin, slightly soluble in liquid ammonia, ammonia, insoluble in ether. Slowly decompose above 110 ℃ to precipitate phosphine PH3. Can burn spontaneously. Loss of crystal water at 200 ℃. Sodium hypophosphite is a strong reducing agent. Strong heat or contact with potassium chlorate and other oxidants can cause an explosion. Anhydrous is white crystalline powder, easy to deliquesce, soluble in glycerin and hot ethanol, soluble in water, cold ethanol, slightly soluble in absolute ethanol, insoluble in ether. The aqueous solution is neutral. Preparation method: Sodium hypophosphite can be obtained by the action of hypophosphorous acid and soda ash. Uses: used as gas analysis reagents, arsenic and iodate reagents, medical nerve supplements, etc. Anhydrous is a reagent for measuring arsenic and copper, and is used in medicine and electroless nickel plating. |
preparation method and characteristics | 1. one-step one-step method refers to the method of directly preparing sodium hypophosphite by reacting yellow phosphorus with one of the following reactants:(l)NaOH,(2) mixture of alkaline earth metal hydroxide and NaOH (mainly NaOH),(3) mixture of alkaline earth metal hydroxide and Na2CO3. For example, yellow phosphorus is heated and reacted with a mixture of lime milk and Na2CO3 solution in an inert atmosphere to release phosphine and hydrogen. After the reaction, the reactants are filtered and separated. The filtrate is sodium hypophosphite solution. The filter cake is composed of unreacted lime and calcium phosphite, calcium phosphate, etc. The filtrate is passed CO2 to remove the calcium hydroxide dissolved in it, filtered, and the filtrate is concentrated under reduced pressure, and finally NaH2PO2 · H2O is obtained. The one-step process is simpler, can produce a more concentrated solution, lower energy consumption, and higher product yield. One-step method has become the main method of industrial production of sodium hypophosphite. 2. Two-step method (metathesis method) The two-step method is to first use yellow phosphorus to react with alkaline earth metal hydroxides in an inert atmosphere, or react with a mixture of alkaline earth metal hydroxides and NaOH (mainly alkaline earth metal hydrides), To obtain alkaline earth metal hypophosphite, and then metathesis alkaline earth metal hypophosphite with sodium carbonate to obtain sodium hypophosphite. Nitrogen is commonly used as inert gas. The most commonly used alkaline earth metal hydroxide is Ca(OH)2. Barium hydroxide, magnesium hydroxide, etc. can also be used, but the raw material cost is higher. The two-step process has a long process, with one more filtration and washing process, and the solubility of calcium hypophosphite is lower than that of sodium hypophosphite. In order to reduce the amount of hypophosphite remaining in the filter cake, the amount of washing water must be increased, and the washing liquid must be combined with the filtrate. The solution thus obtained is very dilute and consumes a lot of energy for evaporation and concentration. 3. Electrochemical method uses the anode part of the diaphragm electrolytic cell to electrochemically oxidize phosphorus in alkali metal hydroxide to obtain alkali metal hypophosphite. Under the current intensity of 2~3 A, electrochemical oxidation is carried out to reduce the amount of toxic PH3 generated, thus improving the working conditions. 4. The one-step continuous method controlled by the electronic computer will carry out one-step continuous production of elemental phosphorus, sodium hydroxide or calcium hydroxide. The pure sodium hypophosphite solution is sent to the continuous crystallizer. The steam in each process can be recycled to save energy. All waste water is recycled, and the gas phosphine and hydrogen are converted into phosphoric acid in a continuous combustion chamber, and calcium phosphite is filtered to remove. The whole process is controlled by an electronic computer. In case of danger, the computer can close the relevant process and eliminate the operator's wrong instructions. Due to the computer control, the produced sodium hypophosphite is of good quality and the purity exceeds 99%. 5. Hydrolysis of phosphorus trihalide hydrolyzes phosphorus trihalide to generate hypophosphorous acid, which reacts with sodium hydroxide to generate sodium hypophosphite. This method is more expensive to produce raw materials, and waste (such as hydrogen halide gas) is more troublesome to deal with if it is not used properly. However, the production process of this method is simple, and the trace element impurities in the product are less, which can meet the requirements of some special industries for high-quality sodium hypophosphite. Therefore, it also has certain industrial application value. 6. Preparation of sodium hypophosphite by high-temperature reaction of phosphorus. Phosphorus directly reacts with oxygen at high temperature to generate phosphorous or hypophosphite anhydride, and hydrolyzes to obtain corresponding acids. After separation, it reacts with sodium hydroxide to generate sodium hypophosphite and sodium phosphite. The method has high production efficiency and high total phosphorus yield. However, what is obtained is a mixture, and the separation process is more complicated, so it is generally less used. 7. Using PH3 to prepare sodium hypophosphite two-step method and one-step method to produce PH3 waste gas. The gas is toxic and burns when it encounters air, which is very dangerous. The usual treatment method is to absorb water after combustion to make dilute phosphoric acid. A better method is to react PH3 with peroxide (such as H2O2), NaClO, or halogen (such as I2, Br2, etc.), strictly control the reaction process to oxidize it to hypophosphoric acid, and then react with alkali to form Sodium hypophosphite. This method has two major advantages: one is waste utilization, and the other is high product quality, which basically does not contain trace element impurities, which can meet the special needs of some high-tech industries. As a one-step comprehensive utilization, it is valued by manufacturers. |
product standard | my country has a long history of producing sodium hypophosphite, but it has been an enterprise standard that has been implemented for a long time. In recent years, special standard ZBG1218-89 has been formulated, but it is still used as an industrial product standard and only stipulates six indicators. Eleven indicators are specified for foreign-specific indicators. Table 1 is the domestic and foreign product standards of sodium hypophosphite Table 2 is the comparison of sodium hypophosphite standards. From the table, it can be seen that foreign countries have strict requirements on impurity indicators due to different application fields. Therefore, domestic enterprises must also comply with market requirements and make great efforts to improve product quality to meet the needs of different purposes. The following is a brief description of the main impurity treatment process. (1)HPO32-removal ① Select appropriate reaction catalyst and side reaction inhibitor to reduce the occurrence of side reactions as much as possible, thereby reducing the total amount of HPO32-in the system and reducing the difficulty of phosphite removal. (2) Use calcium compounds and phosphite to form calcium phosphite precipitation and remove phosphite. Using this method, attention should be paid to the selection of calcium compounds and the addition amount should be strictly controlled to prevent the formation of new pollution. (3) Select complexes or chelates that can enrich phosphite or can co-precipitate with phosphite to remove phosphite. Pay attention to the selection of complexes or chelates that do not produce secondary contamination. ④ Using the different characteristics of sodium hypophosphite and phosphite crystallization, as well as the difference in solubility of sodium hypophosphite and phosphite in water, comprehensive regulation in different processes such as crystallization, centrifugation, and drying can make the product The content of phosphate is less than 0.1%. This method does not need to add treatment agent, but it requires high system operation and control, which is difficult for general factories to achieve. (5) Use reaction by-products (which contain excess calcium ions) to treat sodium hypophosphite solution to remove phosphite. Waste to remove impurities, does not increase the burden of the system, there is no danger of secondary pollution. (2)Ca2 + removal ① adjust the pH value of sodium hypophosphite solution with H3PO4 to generate calcium phosphate precipitation with calcium ions. This method can achieve ideal results, the removal rate of calcium ions can reach 99.6%, and the calcium content in the solution is 0.01g/L. (2) Using ion exchange resin to treat calcium ions in the solution, a solution with a calcium content of 0.0055% can be obtained. This method of equipment investment is larger, resin regeneration is also more troublesome. (3) to the sodium hypophosphite solution into the carbon dioxide gas, so that and calcium ions to form calcium carbonate precipitation. This method is simple, effective and does not cause secondary pollution to calcium ions in the form of Ca(OH)2. However, if the calcium ions in the system exist in the form of Ca(H2PO2)2, CaHPO3, etc., they cannot be removed. (4) Use H3PO3 to adjust the pH value of sodium hypophosphite solution, so that calcium ions and H3PO3 generate CaHPO3 precipitation and remove. ⑤ H3PO3 combined with ion exchange resin. First use H3PO3 to remove most calcium ions and then use ion exchange resin to remove trace calcium ions. (3)SO42-removal of SO42-is brought into the system from the reaction raw materials. Therefore, selecting the appropriate raw materials is the simplest method. Once SO42-occurs in the system, the usual method is to add barium salt to make it precipitate with SO42-to generate barium sulfate and remove it. (4)Cl-removal Since the Cl-content in sodium hypophosphite solution is between 0.01% and 1%, ion exchange resin method is usually used to remove Cl. (5)Fe removal of the original Fe is brought into the system by the reaction raw materials. In the strong alkaline medium, most Fe will become Fe(OH)3 and be removed by precipitation. A simple way to remove Fe is to increase the pH value of sodium hypophosphite solution, and then enter the next process after Fe precipitation is complete. (6) Na2S, H2S or polysulfone compounds and As, Pb are used for removal of A s, Pb and heavy metals to form insoluble salts, or appropriate complexes and chelates are selected to form complex precipitates with As, Pb, etc. |
Use | 1. In the production of electronic computer hard disks, it is used for the treatment of electromagnetic shielding; 2. As a reducing agent for the surface metallization of metal and non-metal materials, Used for chemical plating, such as chemical nickel plating; 3. Engineering plastic stabilizer, such as polyvinyl chloride light and color stabilizer, engineering plastic polycarbonate heat stabilizer, polyvinyl butyl ether stabilizer; 4. Food additives, used to make bacon and cured meat; 5. Nutrition enhancer; 6. Stabilize and bleach fatty acids; 7. Improve the yield and quality of sulfate pulp; 8. Dearsenic removal from acidic wastewater; 9. Plant Fungicide for whole plant or local use; 10. Used as the main raw material for stainless steel of ordinary steel; 11. Organic synthetic reducing agent, such as the reduction of some nitro compounds. Used as an analytical reagent and also used in clinical testing Reducing agent, activator, molecular weight regulator and heat stabilizer; arsenic and iodate reagent |
precautions | it is relatively stable when stored in a dry state. it will explode when exposed to strong heat, and it will explode when mixed with oxidant. when heated over 200 ℃, it will quickly decompose and release spontaneous and toxic phosphine. sodium hypophosphite solution can decompose and release hydrogen in the presence of some metal powder. Heating and evaporation under normal pressure will explode. In the production process of sodium hypophosphite, from raw materials to intermediate products and by-products are toxic and dangerous to varying degrees. Yellow phosphorus spontaneously ignites, steam is toxic, and the intermediate product phosphine is flammable, explosive, and highly toxic gas. Raw caustic soda is corrosive, so it requires closed and pipeline production. The rotating shaft part should have a good seal. The by-products of sodium hypophosphite production are mainly calcium phosphite and dilute phosphoric acid, which are relatively less toxic, but still need to pay attention to recovery. |