Molecular formula: (NH₄)₂Mo₄O₁₃·2H₂O. White or light yellow powder, low-soluble in water and inorganic acid, soluble in alkali easily, insoluble in alcohol and acetone. It mainly apply to producing molybdenum powder, ertilizer containing trace elements, ceramic colours, and other molybdic chemical compounds. Packing: in fibre board drums or antirust iron drums lined with double-decker plastic bags.
Specifications：

Grade	MSA-1	MSA-2	MSA-3
Si	0.0006	0.0010	0.002
0Al	0.0006	0.0006	0.002
Fe	0.0006	0.0003	0.005
Cu	0.0003	0.0005	---
Mg	0.0006	0.0006	0.002
Ni	0.0003	0.0005	0.001
Mn	0.0003	0.0006	---
P	0.0005	0.0005	0.001
K	0.01	0.08	---
Na	0.001/div>	0.003	---
Ca	0.0003	0.001	---
Pb	0.0005	0.0005	0.0006
Bi	---	---	0.0006
Sn	0.0005	0.0005	0.0006
Sb	---	---	0.0006
Cd	---	---	0.0006