sulfamic acid

　Aminosulfonic acid: The molecular formula of aminosulfonic acid is NH2S03H. The commercially available product is a white powder; at room temperature, as long as it remains dry and does not come into contact with water, the solid sulfamic acid is non-hygroscopic and relatively stable. The aqueous solution of sulfamic acid has a strong acidity on par with that of hydrochloric acid and sulfuric acid; hence it is also known as solid sulfuric acid. It is non-volatile, odorless, and has extremely low toxicity to the human body. The aqueous solution of sulfamic acid acts more slowly on iron corrosion products; adding some sodium chloride can cause hydrochloric acid to be produced gradually, thereby effectively dissolving iron scale. An aqueous solution of sulfamic acid can remove scale and corrosion products from the surfaces of equipment made from materials such as iron, steel, copper, and stainless steel. Furthermore, it is the only acid that can be used for cleaning galvanized metal surfaces. When cleaning with an aqueous solution of sulfamic acid, the temperature is generally kept at no more than 66°C (to prevent the decomposition of sulfamic acid), and the concentration is kept at no more than 10%. 　　Ammonium sulfonate is an important fine chemical product that is widely used in various fields such as metal and ceramic manufacturing, industrial equipment, household cleaners, petroleum processing agents and cleaners, electroplating industry chemicals, electrochemical polishing agents, asphalt emulsifiers, etchants, sulfonating agents for the dye, pharmaceutical, and pigment industries, coloring agents, high-efficiency bleaching agents, flame retardants for fibers and paper, softeners, resin cross-linking accelerators, herbicides, desiccants, and as standard analytical reagents. 　　Aminosulfonic acid can be made into extremely pure crystals that remain stable at room temperature; its aqueous solution possesses the same high acidity as hydrochloric acid and sulfuric acid, and it is also known as solid sulfuric acid. It is non-volatile and non-hygroscopic, with extremely low toxicity to humans; however, the skin should not be in contact with sulfamic acid for long periods of time, and it must not come into contact with the eyes. The production process of sulfamic acid is simple, the reactions are easy to control, the raw materials and equipment are readily available, the wastewater is easy to treat, and the by-products can be effectively utilized. This product can replace sulfuric acid, and its packaging, storage, and transportation are all convenient. 　　Since the industrial production of sulfamic acid began, its production volume has increased accordingly as its applications have expanded. Japan’s annual production in 1965 was 14,000 tons, and in 1980 the price per kilogram was 140–160 yen. The Japanese manufacturer is Nissan Chemical Company of Fuji, with an annual production capacity of 7.2 thousand tons ； Daiki Industry in Osaka has an annual production capacity of 3,000 tons. The annual production in the United States is 50,000 tons, and in 1984 its price per 100 pounds was $38 to $41. In our country, the amino sulfonic acid production plants include the Wuxi Sulfuric Acid Plant, whose expanded production capacity is 600 tons per year, and the Shanghai Sulfuric Acid Plant, with an annual production capacity of 1,000 tons. The price is 2,800 to 3,000 yuan per ton. 　　Sulfamic acid 　　CAS No.: 5329-14-6 　　Properties of sulfamic acid 　　Physical properties of sulfamic acid 　　Molecular weight: 97.09 　　Melting point: 215–225°C (decomposition) 　　Water solubility: 146.8 g/L (20°C) 　　Appearance: White rhombic crystals of H2NSO2OH. It is tasteless and odorless, non-volatile, and non-hygroscopic. Density: 2.126. Melting point: 205°C (decomposition begins at 209°C; at 260°C, SO2, SO3, N2, water, and other trace substances are released during decomposition). Refractive index: 1.553 for type α, 1.563 for type β, and 1.568 for type γ. Refractive index range (25±3°C): 1.553–1.568. Dissociation constant: 1.10×10-2. Enthalpy of formation: 685.9 kJ/mol. Solubility: It is readily soluble in water and liquid ammonia; it exhibits moderate acidity in aqueous solutions. It is slightly soluble in methanol, but insoluble in ethanol and ether. 　　Taking advantage of the fact that sulfamic acid and its salts can form soluble salts with various metal compounds, which dissolve in water without forming precipitates and cause little corrosion to metals, they can be used as cleaning agents to remove rust and scale that form over time in machines and equipment made of iron, steel, copper, stainless steel, lead, ceramics, etc., during use. 　　Aminosulfonic acid, as a cleaning agent, is a solid that offers many advantages such as ease of storage and transportation as well as simplicity in preparation, making it particularly suitable for use over long distances. 　　Aminosulfonic acid cleaning agents have a wide range of applications and can be used to clean boilers, condensers, heat exchangers, jackets, and chemical pipelines. Use it in breweries to remove scale from glass-lined tanks, kettles, open beer coolers, and beer barrels ； Cleaning evaporators in enamel factories, as well as equipment in paper mills, etc ； In terms of air conditioning, it can remove rust and scale from the cooling system and evaporative condenser ； It is used on seagoing vessels to remove algae and scale from seawater evaporators (distillation equipment), heat exchangers, and brine heaters ； It can remove scale from copper kettles, radiators, tableware washing machines, silverware, toilets, tiles, as well as equipment used in food and cheese processing ； It can remove proteins deposited on cookers, as well as deposits from disinfectants used in meat, vegetable, and cheese processing plants. The U.S. Department of Agriculture permits the use of ammonium sulfite as an acidic cleaning agent in businesses that process fresh meat, poultry, rabbits, and eggs. 　　Inject an aminosulfonic acid solution into the carbonate rock oil reservoir. Since sulfamic acid readily reacts with the rocks in the oil layer, it prevents the deposition of salts resulting from such reactions. The treatment cost is slightly higher than that using hydrochloric acid, but oil production doubles. The United States uses 48.5% potassium hydroxyacetate and 3.4% sulfamic acid. A 0.1–3% aqueous solution of wetting agent is used to clean the gypsum scale in oil well casings; the treatment takes approximately 30 hours. For automobile bodies, tin-zinc alloy plating is applied first, followed by painting, which increases the adhesion of the paint film. 　　Aminosulfonic acid is commonly used in gilding or alloy plating; the plating solutions for gilding, silver plating, and gold-silver alloys contain 60–170 grams of aminosulfonic acid per liter of water. The typical plating solution for silver-plated women’s clothing pins is 125 grams of sulfamic acid per liter of water, which yields a highly shiny silver plating. In the new aqueous gold-plating electrolyte, alkali metal sulfonamides, ammonium sulfonates, or sulfonic acids can be used as compounds that provide conductivity and buffering effects. 　　When recovering from nickel-plating waste liquid, cation exchange resin is used for adsorption, and then the resin is washed with sulfamic acid to desorb what has been adsorbed, thereby regenerating the resin. For example, when treating electroplating wastewater containing 400 ppm of Ni, 50 ml of sulfamic acid at a concentration of 150 g/l is used, resulting in a recovery rate of 2112 g/l of (NH2SO3) and 148 g/l of NiSO4. When repairing nickel-plated parts, it is necessary to plate nickel on top of the existing nickel; for their anodic treatment, 100 grams per liter of sulfamic acid can be used. The surface to be nickel-plated should be cleaned with an 0.003–0.1 molar solution of sulfamic acid before nickel plating. 　　The content of sulfamic acid in the copper plating solution is 3 to 20 liters. Sulfamic acid serves to make the plating layer fine and ductile, as well as to confer high viscosity to it. 　　During iridium plating, when NH2SO3H/Ir ≥ 7, the resulting iridium coating is crack-free; the thickness of the iridium layer is 15 micrometers, and it exhibits strong adhesion. This product shows good performance in automatic anti-pollution devices. 　　When plating rhodium-rhene alloys on silverware and electrical components, the electroplating solution contains 100 grams per liter of sulfamic acid; when the coating thickness is ≤5 microns, it exhibits high hardness and strong corrosion resistance, in addition to being very bright and attractive in appearance. 　　The smooth and attractive rhodium-rhene electrodeposition layer on brass has high hardness and corrosion resistance. The plating solution contains 100 grams per liter of sulfamic acid, 50 grams per liter of concentrated sulfuric acid, 2 grams per liter of rhodium (in the form of sulfate), and 0.05 grams per liter of rhenium [in the form of K3N(RuCl4H2O2)2]. Under conditions of 65°C and 1–2 amperes per square decimeter, the deposition rate is 3–4 milligrams per ampere per square decimeter. 　　Italy has replaced fluorosilicic acid baths with lead amino sulfonate baths to reduce pollution. It has various applications in the anti-corrosion aluminum industry. The product has a good luster and excellent processability. 　　Packaging: Packed in 25kg plastic woven bags with plastic lining; store and transport in a way that protects them from sunlight and rain, do not store them together with sharp objects, and keep them in a clean, dry warehouse to avoid moisture. Packed in plastic woven bags of 250kg, 500kg, or 1000kg weight, with a plastic lining for protection; storage and transportation should be done in a way that protects them from sunlight and rain. Storage: Store in a clean and dry warehouse, away from sunlight, rain, and humidity; do not store them together with sharp objects. Packaged in plastic bags. Store in a cool, well-ventilated, and dry place, and handle it in accordance with the regulations for general chemicals. Toxicity protection: This product is low in toxicity. It can cause some irritation to the skin and eyes. Production equipment should be sealed, and operators must wear appropriate protective gear. Safety: Aminosulfonic acid products do not burn or explode on their own, but they release toxic gases such as SO2, SO3, NH3, etc. when exposed to fire. Its aqueous solution can burn the eyes and is irritating to the nose, throat, and skin; in case of contact, it should be rinsed thoroughly with water.

That expert could provide some practical advice, such as material ratios and equipment investment costs, of course, if it’s convenient for them. Thank you!

Item Consumption per ton of product Urea: 0.45 t Fuming sulfuric acid (20% free SO3): 3.1 t Water: 12 t Electricity: 320 kW·h Steam (low pressure): 1.8 t Packaging bags: 25 By-product: Sulfuric acid (70% concentration): 3.5 t (by-product) Subtotal Equipment depreciation Maintenance costs Labor costs Workshop expenses Workshop costs Factory management costs Total factory costs

1Kt/a Main equipment: 5000L sulfonation enamel reaction kettle, four units； Crystalline enamel reaction kettle, 3000L, three units ； One filter, one dryer

What is the heat dissipation efficiency of glass-lined tanks? I’m referring to situations where there is a high production capacity, and the volume of the crystallization tank reaches a certain level, such as 20 m3 per tank – which manufacturers offer such tanks?