Sulfamic acid

The molecular formula of sulfamic acid is NH2SO3H. The commercially available product is a white powder. At room temperature, as long as it is kept dry and not in contact with water, the solid sulfamic acid does not absorb moisture and is relatively stable. The aqueous solution of sulfamic acid has the same strong acidity as hydrochloric acid and sulfuric acid, so it is also called solid sulfuric acid. It has the characteristics of non-volatile, odorless and minimal toxicity to the human body. The sulfamic acid aqueous solution has a slower corrosive effect on iron and other metals. Some sodium chloride can be added to convert it into hydrochloric acid to effectively dissolve iron scale. The sulfamic acid aqueous solution can remove scale and corrosion products on the surface of equipment made of iron, steel, copper, stainless steel and other materials. In addition, it is also a single acid that can be used for cleaning galvanized metal surfaces. When the ratio is 1:4 with water. Can corrode eggshells (calcium carbonate and magnesium carbonate).

【Basic information】

【Properties and Stability】

1. In a dry environment at room temperature, sulfamic acid is relatively stable, as long as it does not contact with water, the solid does not absorb moisture. It decomposes at high temperature and emits toxic gases such as nitrogen and sulfur oxides. Sulfamic acid and its salts and various metal compounds can generate soluble salts. Decomposes at 260℃. Soluble in water, liquid ammonia, slightly soluble in methanol, insoluble in ethanol, ether organic solvents, carbon disulfide, and liquid sulfurous acid. The aqueous solution is highly ionized. strong acid. The reactivity to organic matter is weak, and its salts are easily soluble in water (except alkaline mercury salts). When its aqueous solution is boiled, it is hydrolyzed to ammonium sulfate. poisonous! It is not volatile nor hygroscopic, and is stable at room temperature. It is soluble in water, and the aqueous solution is acidic. Hydrolysis in boiling water generates NH+4 and HSO-4.

2. Sulfamic acid does not absorb moisture in the air and can be stored for a long time at room temperature and in a dry environment. The chemical properties are stable, and its aqueous solution has strong acidity, which is corrosive to metals.

3. Solubility: soluble in water and liquid ammonia, slightly soluble in ethanol and methanol, slightly soluble in acetone and insoluble in ether. Insoluble in organic solvents. Easily soluble in nitrogen-containing lye and liquid nitrogen; also soluble in nitrogen-containing organic reagents such as pyridine; hardly soluble in ethanol and methanol. It is moderately soluble in water and difficult to mix with common non-polar solvents such as THF or toluene.

4. Stability: stable

5. Incompatible materials: strong oxidant, strong alkali

6. Conditions to avoid contact: Heat

7. Polymerization hazards: no polymerization

8. Decomposition products: sulfur oxides, nitrogen oxides

[Overview of dangers]

Toxicity protection: The product is low in toxicity. It has a certain stimulating effect on eyes and eyes. Production equipment should be closed, and operators should wear protective gear

~: Dust or solution is irritating to eyes and ~, and can cause burns. The higher allowable concentration is 10mg/m3. Rinse with water when the eyes are irritated, and seek medical treatment for severe cases. ~ Wash with water when in contact, and then wash thoroughly with soap. At the entrance, you should rinse your mouth immediately and send #% for diagnosis and treatment. Packed in polyethylene plastic bags lined with 25kg net weight. Store in a cool, ventilated and dry place. The packaging should be sealed to prevent moisture. Protect from rain and sunlight during transportation. Wear gas masks and gloves when disposing of escaping materials, sweep them up with sand and soil or rinse them with water. In case of fire, water, sand and fire extinguishers can be used to put out the fire.

Hazard statement

Dangerous code: Xi

Danger level: R36/38- R52/53

~ Grade: S26- S28- S61

Regulatory information

It is an acid corrosive product in hazardous chemicals.

[Precautions for storage and transportation]

store

Keep sealed and dry. Airtightly package and store in a dry and ventilated place. It is stored and transported in equal parts with oxidants and alkalis. Pay attention to personal protection, and direct physical contact is strictly prohibited. If swallowed, rinse your mouth with water, drink milk or egg white.

Transportation considerations

Railway transportation shall be carried out in strict accordance with the dangerous goods distribution table in the "Dangerous Goods Transportation Regulations" of the Ministry of Railways. The packaging should be complete when shipping, and the loading should be secure. During transportation, ensure that the container does not leak, collapse, fall, or be damaged. Mixed shipment and transportation with oxidants, alkalis, edible chemicals, etc. is strictly prohibited. Transportation vehicles should be equipped with leakage emergency treatment equipment during transportation. Avoid exposure to the sun, rain, and high temperature during transportation.

【Main effect】

Aminosulfonic acid is used as a cleaning agent, because it is a solid, has many advantages such as convenient storage, transportation, and easy preparation, and is especially suitable for long-distance use.

The sulfamic acid cleaning agent has a wide range of applications, and can be used to clean boilers, condensers, heat exchangers, jackets and chemical pipelines. It is used in breweries ~ glass-lined storage tanks, pots, open beer coolers, scale layers on beer barrels; cleaning evaporators in enamel plants, and equipment in paper mills; in air conditioning, cooling systems and evaporative condensers can be removed Rust and scale; seawater evaporator (distillation equipment), heat exchanger and salt water heater with seaweed and scale; it can clean copper pots, radiators, tableware washing mechanism, silverware, toilets, tiles, The scale of food and milk processing equipment; the protein deposited on the cooker and the deposits used in the processing plants of fresh meat, vegetables and cheese. The U.S. Department of Agriculture allows sulfamic acid to be used as an acid cleaning agent in fresh meat, poultry, rabbit, and egg processing enterprises.

The sulfamic acid solution is injected into the carbonate reservoir. Because sulfamic acid easily reacts with oil layer rocks, it can avoid the deposition of salt generated by the reaction, and the processing cost is slightly higher than that of hydrochloric acid, but the oil output doubles. The United States uses 48.5% potassium glycolate and 3.4% sulfamic acid. 0.1-3% aqueous solution of wetting agent cleans gypsum scale layer in oil well casing, treatment time is about 30 hours

The car shell is first electroplated with tin-zinc alloy and then painted, the adhesion of the paint film will increase.

Sulfamic acid is commonly used for gold or alloy plating. The electroplating solution for gold, silver, and gold-silver alloys contains 60 to 170 grams of sulfamic acid per liter of water. The typical electroplating solution for silver-plated women's clothing needles contains 125 grams of sulfamic acid per liter of water to obtain very bright silver plating. In the new aqueous gold plating bath, alkali metal sulfamate, ammonium sulfamate or sulfamate can be used as conductive and buffering compounds.

When recovering from the nickel plating waste liquid, it is treated with cation exchange resin adsorption and then washed with sulfamic acid to desorb the adsorbed resin and the resin is regenerated. For example, to process 400ppm Ni electroplating waste liquid, use 150 g/L sulfamic acid 50 ml, and recover (NH2SO3) 2112 g/L and NiSO4148 g/L. When repairing nickel-plated parts, it is necessary to plate nickel on nickel, which can be treated with 100 g/L sulfamic acid during anodizing. Before nickel plating, the nickel-plated surface should be cleaned with 0.003-0.1 mol sulfamic acid solution.

The content of sulfamic acid in the copper plating solution is 3-20 liters. The function of sulfamic acid is to make the plating layer dense and ductile, and its viscosity is high.

When iridium plating is NH2SO3H/Ir≥7, the obtained iridium coating has no cracks, the thickness of the iridium layer is 15 microns, and the adhesion is large. The product has good activity in automatic anti-pollution equipment.

When rhodium-rhenium alloy is plated on silverware and electrical components, the electro-fluid contains sulfamic acid at 100 g/l. When the thickness of the plating layer is ≤ 5 microns, it will have high hardness and strong corrosion resistance, and The plating layer is very bright and beautiful.

The bright and beautiful rhodium-rhenium electroplating layer on brass has high hardness and corrosion resistance. The electroplating solution contains sulfamic acid 100 g/l, concentrated sulfuric acid 50 g/l, rhodium (such as sulfate) 2 g/l, rhenium [ For example, K3N (RuCl4H2O2)2] 0.05 g/L, at 65°C and 1 to 2 A/dm2, the deposition rate is 3 to 4 mg/A min.

Italy has used lead sulfamate bath instead of fluorosilicic acid bath, which can reduce pollution. There are many uses in the anti-corrosion aluminum industry. The product has good gloss and excellent processing performance.

Amino sulfonic acid is a solid acid that is cheap and easy to obtain and has good stability. It has a good catalytic effect on the esterification reaction of organic acids and does not corrode equipment.