Background and overview[1]
Magnesium pyrophosphate is also known as “magnesium diphosphate”. Magnesium pyrophosphate is a colorless flaky monoclinic crystal, insoluble in water and ethanol, easily soluble in inorganic acids, and also soluble in sulfurous acid or sodium pyrophosphate solution. Preparation method: The trihydrate is first prepared by the interaction between sodium pyrophosphate aqueous solution and magnesium chloride aqueous solution, and then heated and dehydrated at 100°C, or obtained by burning magnesium ammonium phosphate.
Acid hydrolysis research[2]
In view of the problem of magnesium pyrophosphate being generated during the pyrolysis of magnesium ammonium phosphate, Li Haibo and others conducted a study on the acidolysis of magnesium pyrophosphate in the pyrolysis product, and investigated the effects of pH value, temperature, reaction time, etc. on magnesium pyrophosphate acid. Through the influence of solution behavior, the transformation rules of pyrophosphate to orthophosphate were obtained. Studies have shown that acidolysis can effectively convert magnesium pyrophosphate that does not have the ability to precipitate ammonia nitrogen into magnesium phosphate that has an efficient precipitating effect on ammonia nitrogen, thereby realizing the recycling of magnesium ammonium phosphate. The study also examined the ammonia nitrogen precipitation performance of the acid hydrolysis product, including the effects of pH value, dosage, etc. on the ammonia nitrogen precipitation performance. The research results show that under appropriate pyrolysis and acidolysis conditions, magnesium ammonium phosphate can be recycled for 5 times and still have more than 90% ammonia nitrogen removal performance.
Apply[3]
CN201610630491.7 discloses an ultra-high vapor pressure aerated ceramsite concrete and its manufacturing process, which consists of the following components in proportion by weight: pure water, mortar, (copper sulfate-ferric nitrate-chloride Zinc-tin oxide) chelate, calcium sulfate (CaSO4), magnesium borate, fly ash, silica, quicklime, rubidium alcohol nanoparticles, citric acid, magnesium pyrophosphate, desulfurization Lead and zinc tailings powder, tris (2-toluene) phosphate, HBS lignin, ceramsite. The advantages of this invention are: it can digest tailings, reduce pollution, turn waste into treasure, and reduce the production cost of aerated concrete; it can take into account light weight and high strength, thermal insulation, impermeability and waterproofing, fire and flame retardancy, sound insulation and noise reduction, It is green, environmentally friendly, convenient to construct, durable, economical and practical; it has the advantages of fast construction speed, little restriction by climatic conditions, saving labor force, effectively shortening the construction period, saving construction costs, and improving construction quality.
