Name | Ammonium dimolybdate |
Synonyms | Ammonium dimolybdate AMMONIUM DIMOLYBDATE AMMONIUM MOLYBDATE TS Ammonium di-molybdate AMMONIUM MOLYBDATE (DI) AMMONIUM MOLYBDATE REAGENT Ammoniumdimolybdatewhitepowder AMMONIUM MOLYBDENUM OXIDE (DI) Ammonium molybdenum oxide ((NH4)2Mo2O7) |
CAS | 27546-07-2 |
EINECS | 248-517-2 |
InChI | InChI=1/2Mo.2H3N.7O/h;;2*1H3;;;;;;;/q2*-1;;;;;;;;;/p+2/rMo2O7.2H3N/c3-1(4,5)9-2(6,7)8;;/h;2*1H3/q-2;;/p+2 |
Molecular Formula | H6MoNO+ |
Molar Mass | 132 |
Density | 3.1 |
Melting Point | 300 °C |
Water Solubility | Soluble in water. |
Appearance | Powder |
Color | white |
Exposure Limit | ACGIH: TWA 0.5 mg/m3NIOSH: IDLH 1000 mg/m3 |
Storage Condition | Sealed in dry,Room Temperature |
MDL | MFCD00010882 |
Physical and Chemical Properties | White crystals |
Use | Raw materials for dyes, pigments, catalysts, fire retardants, trace element fertilizers, ceramic pigments and other compounds |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | 24/25 - Avoid contact with skin and eyes. |
TSCA | Yes |
HS Code | 28417010 |
Raw Materials | ammonium molybdate |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
overview | ammonium dimolybdate, commonly known as ADM, commonly known as (NH4)2Mo2O7, is a white powder crystal, the product has no visible inclusions, is soluble in alkali and water, and is insoluble in alcohol and acetone. It is mainly prepared by evaporation crystallization method. In addition to being suitable for roasting to produce pure molybdenum trioxide and reduced molybdenum powder, molybdenum tablets, molybdenum wires, molybdenum elements and ammonium dimolybdate; it is also widely used in the production of hydrogenation, desulfurization and other petroleum refining catalysts, fertilizer catalysts and dyes. |
application | 1. used to make catalysts, metal molybdenum, pigments, metal surface treatment, corrosion inhibitors, trace element fertilizers, etc. 2. the raw materials used for preparing molybdenum powder, ceramic pigments and other molybdenum compounds are roasting to produce pure molybdenum trioxide, reducing molybdenum powder, and manufacturing molybdenum flakes, molybdenum wires and molybdenum components. 3. It is used to produce petroleum refiners such as hydrogenation and desulfurization, fertilizer catalysts and dyes. |
use | ammonium dimolybdate can be used to prepare molybdenum trioxide and molybdenum powder, and then can be processed into molybdenum strips, molybdenum electrodes, molybdenum slabs, molybdenum wires, molybdenum foils and other molybdenum alloy products, which are widely used in steel, cermets, electric light sources, metallurgy, aerospace and military industries. Petroleum catalyst, a new type of molybdenum salt in powder metallurgy. The petrochemical industry is used as a catalyst, and the metallurgical industry is used to make molybdenum powder, molybdenum strips, molybdenum wires, molybdenum blanks, molybdenum tablets, etc., and can also be used as trace non-vegetarian fertilizers to make ceramic pigments, pigments and other molybdenum compounds Raw materials. Raw materials for dyes, pigments, catalysts, fire protection agents, trace element fertilizers, ceramic pigments and other compounds Raw materials mainly used for preparing molybdenum powder, making ceramic pigments and other molybdenum compounds |
synthesis method | a method for preparing ammonium dimolybdate from a molybdenum-containing solution includes the following steps:(1) normal temperature vulcanization process: stirring the molybdenum-containing solution, adding ammonium sulfide at the same time, adjusting the color of the solution from blue to colorless, standing for 24 hours, and then passing the supernatant through a cardboard filter, the filtrate is used as the raw material for the next acid precipitation process;(2) acid precipitation process: the filtrate obtained in the previous process is stirred with anchor blades, industrial concentrated sulfuric acid is added, the pH value of the filtrate is adjusted to 2.8, and the filtrate is adsorbed by ion exchange column after stirring for 30min, and the filter residue is rinsed with pure water to obtain crude ammonium tetramolybdate; in the process of adding industrial concentrated sulfuric acid, the adding speed should be controlled to control the temperature of the solution below 45 ℃; among them, the ion exchange column adopts D314 resin, 3-stage adsorption, 1-stage analytical four-stage series adsorption to remove impurities; the flow rate of the acid precipitation mother liquor is controlled at 2 times/hour adsorption; the analytical liquid adopts ammonia water with a concentration of 5N, The flow rate of 1 times/hour from top to bottom is analyzed; regeneration adopts a solution with 4-6% sulfuric acid content from top to bottom at a flow rate of 1 times/hour;(3) Re-dissolution evaporation crystallization process: heat pure water to boiling, then add crude ammonium tetramolybdate, then add ammonia water to adjust the pH value to 6.5~7.0, filter while hot, and the obtained filtrate is put into a crystallization kettle, and vacuum evaporation concentration is carried out at a vacuum degree of -0.05 ~-0.09Mpa and a temperature of 75 ℃. After 55% water is evaporated, filter, the mother liquor returns to step (2) to carry out acid precipitation again; The crystal is dried by microwave so that the water content of the crystal is lower than 0.5%, I .e. ammonium dimolybdate is obtained. |
preparation method | 1. ammonium dimolybdate is produced by resolution crystallization method. The production process is shown in Figure 1. Fig. 1 is a flow chart of the production process of resolution crystallization. the operation steps are as follows:(1) ammonium tetramolybdate dissolution: pure water is first added to the dissolution kettle according to a certain proportion, the pure water is heated to 70 ℃, and ammonium tetramolybdate and ammonia water are slowly added in the stirring state to control the concentration of ammonium molybdate to about MoO3 400g/ L and the pH value is 5.5~6.5. (2) filtration of ammonium molybdate solution: after ammonium tetramolybdate is dissolved, an appropriate amount of steam is introduced to raise the temperature of ammonium molybdate solution to 80~90 ℃, heat filter with a plate and frame filter, and the filtrate is put into a crystallization kettle. (3) Cooling crystallization: In the cooling crystallization kettle, in the stirring state, after the initial crystal nucleus that acts as a seed crystal is formed, cooling water is introduced to cool to room temperature, ammonium dimolybdate crystals are precipitated, the material is drained, and the centrifuge is dehydrated to separate the ammonium dimolybdate product. 2. Preparation by evaporation crystallization method. The specific process flow chart is shown in Figure 2. Fig. 2 is a flow chart of the production process by evaporation crystallization. the reaction equation is as follows:(NH4)2Mo4O13 3H2O 6NH3=4(NH4)2MoO42(NH4)2MoO4 =(NH4)2Mo2O7 H2O 2NH3 = H2O NH3 = NH4OH. the operation steps are: adding liquid ammonia in the reaction kettle with pure water, adjusting the pH value of the solution, adding ammonium tetramolybdate (AQM), adjusting the density and pH value of the solution, and heating. The feed liquid enters the evaporation crystallizer after being filtered, and the quantitative reagent A is added after the evaporation process is carried out for a certain period of time, and the evaporation process ends. The slurry is dehydrated by a centrifuge, the wet material is put into a far infrared dryer for drying at a certain temperature, and the dry material is filtered and mixed in the mixer to become the product. |
Production method | Ammonium dimolybdate can be obtained by crystallization in MoO3 solution containing excess NH3. |