Sodium Molybdate (SMD) CAS 7631-95-0

About Sodium Molybdate

Sodium molybdate (Na2MoO4, CAS 7631-95-0) is the sodium salt of molybdic acid. It is produced by dissolving molybdenum trioxide (MoO3) in sodium hydroxide solution, followed by crystallization. The commercial product is commonly available as the dihydrate (Na2MoO4·2H2O), which loses water of crystallization above 100°C to form the anhydrous salt.

Sodium molybdate is highly soluble in water (approximately 84 g/100 mL at 20°C) and insoluble in most organic solvents. It serves as a readily bioavailable source of molybdenum, an essential trace element for plants, animals, and humans. In industrial applications, it functions as a catalyst precursor, corrosion inhibitor, and pigment intermediate.

Specifications

Applications

Agriculture & Animal Feed

Molybdenum source for foliar sprays, seed treatments, and soil fertilizers. Molybdenum is essential for nitrogenase and nitrate reductase enzymes in legumes and other crops. Typical application rates range from 50-200 g per hectare for field crops. Also used as a feed additive for cattle and sheep to prevent molybdenum deficiency and copper-related disorders.

Industrial Catalysts

Precursor for molybdenum-based catalysts used in petroleum refining, hydrodesulfurization (HDS), and selective oxidation reactions. Sodium molybdate is converted to molybdenum trioxide or ammonium molybdate before catalyst impregnation. Used in the production of acrylic acid, acrylonitrile, and formaldehyde catalysts.

Corrosion Inhibition

Anodic corrosion inhibitor for cooling water systems, boiler water treatment, and metalworking fluids. Sodium molybdate forms a protective passive film on ferrous metals. Typical dosage is 50-200 mg/L in open recirculating systems. Often used in combination with zinc salts or phosphonates for synergistic protection.

Pigments & Coatings

Raw material for molybdate-based pigments including molybdate orange and molybdate red. These pigments offer high opacity, heat stability, and corrosion resistance in industrial coatings, plastics, and printing inks. Also used in the production of specialty glass and ceramics.

Other Uses

Electroplating additives, flame retardant synergists, lubricant additives, and as a reagent in analytical chemistry. Used in the production of molybdenum metal powder and molybdenum disulfide (MoS2) lubricants.

Quality Control & Documentation

Each batch is tested before release:

1. Molybdenum content by gravimetric analysis or ICP-OES
2. Purity by acid-base titration
3. Water insolubles by filtration and weighing
4. Chloride and sulfate by ion chromatography
5. Heavy metal analysis by ICP-OES
6. Batch-specific COA accompanies every shipment

Available documentation includes COA, TDS, SDS/MSDS, fertilizer registration certificates, and REACH registration documents. SGS or BV pre-shipment inspection is available on request.

Storage & Handling

Store in a cool, dry, ventilated area in tightly sealed containers. Keep away from strong acids and reducing agents. The product is hygroscopic and should be protected from moisture. Use stainless steel or plastic equipment. Shelf life is 24 months under proper storage conditions.

Wear protective gloves, safety glasses, and dust mask when handling. Avoid inhalation of dust and prolonged skin contact. In case of eye contact, flush with water for 15 minutes and seek medical attention. Molybdenum compounds may cause gout-like symptoms with excessive occupational exposure.

Frequently Asked Questions

What is the difference between anhydrous and dihydrate sodium molybdate?

The dihydrate (Na2MoO4·2H2O) contains two water molecules per formula unit and has a lower molybdenum content (~36%). The anhydrous form (Na2MoO4) contains ~39% molybdenum. Both are chemically equivalent when dissolved in water. Specify the form based on your formulation and moisture requirements.

Can sodium molybdate be mixed with other fertilizers?

Sodium molybdate is compatible with most liquid fertilizers and micronutrient blends. Avoid mixing with high concentrations of copper, zinc, or iron salts, which may form insoluble molybdates. Conduct a jar test before large-scale mixing.

What is the minimum order quantity?

Standard packaging is 25 kg bags and 500 kg big bags. Full container loads (20-25 tons) are typical for bulk orders. Smaller quantities are available for sample and qualification testing.

Is sodium molybdate regulated for agricultural use?

Sodium molybdate is registered as a fertilizer ingredient in most jurisdictions. Agricultural-grade material meets specific heavy metal and impurity limits. Provide your destination country for applicable regulatory documentation.