1. Hydrothermal synthesis method in the closed reactor, the 4∶1(molar ratio) molybdic acid and laurel gum reaction to molybdic acid molecules on the technology of amine, reaction temperature is 150℃, time is 1 day, at this time the light yellow molybdic amine compound turned white, cold to room temperature, aging 48h after the release of products, and then with 33% nitric acid aqueous solution, at room temperature 48h, remove the amine combination The pure nanometer molybdenum trioxide fiber was obtained. The overall hydrothermal and synthetic process is as follows:
MoO3 • 2 h2o – > [C12H26N] 0.5 MoO3.25-2 MoO3 • 2 h2o – MoO32
2. Sublimation method The production of nano molybdenum trioxide by sublimation method is an improvement on the production of pure molybdenum trioxide by traditional method. The method is to sublimate molybdenum trioxide in a closed electric furnace to produce pure molybdenum trioxide. The average particle size of pure molybdenum trioxide is in the micron level. For preparing nanometer molybdenum trioxide sublimation of molybdenum trioxide gas must be rapid cooling to prevent molybdenum oxide particle coagulation or reunion, especially soft reunion. For this purpose, a nitrogen quench system was designed, in which liquid nitrogen was introduced into an induction furnace to rapidly cool the sublimated molybdenum trioxide.
The production process of nanometer molybdenum trioxide includes: 24 ~ 260μm industrial molybdenum oxide powder is fed into electric sublimation furnace by screw conveyor. The processing capacity of electric furnace is 284kg/h. Electric furnace heating to 1093 ~ 1266℃, at this temperature, molybdenum trioxide sublimation, sublimed molybdenum trioxide is quenched by liquid nitrogen.
The liquid nitrogen cooling system is composed of liquid nitrogen storage tank ①, upper and lower valves ②, total temperature and pressure control room ③, thermocouple ④, liquid nitrogen outlet pipe ⑤ and so on. The temperature of liquid nitrogen quenching is 37 ~ 54℃, the best is 48℃, and the inlet pressure of liquid nitrogen is 260 ~ 660Pa. Nano molybdenum trioxide product collection system by collecting funnel ⑥, filter ⑦ and pump ⑨. The collecting funnel is made of SAE316 stainless steel, it is connected with filter ⑦, the pump capacity is 8500L/min, its power depends on the nanometer molybdenum trioxide output. The sublimation furnace was operated for 480min, and 29kg nanometer molybdenum trioxide was produced. The particle size was about 30nm(diameter), the length was about 80-90nm, and the BET was 20-60m2 /g.