White Phosphorus

1.Chemical and Physical Properties

1.1 Chemical Identity

• Chemical Name: White Phosphorus (also known as Yellow Phosphorus)
• Molecular Formula: P₄
• Molecular Weight: 123.895 g/mol
• CAS Number: 7723-14-0
• Structure: Tetrahedral arrangement of four phosphorus atoms with significant ring strain, making it highly unstable and reactive

1.2 Physical Properties

• Appearance: Translucent, waxy solid ranging from white to pale yellow in color
• Odor: Distinctive garlic-like or acrid smell
• Melting Point: 44.15°C (111.47°F)
• Boiling Point: 280.5°C (536.9°F)
• Density: 1.823 g/cm³ at 20°C
• Solubility:
  • Insoluble in water
  • Soluble in carbon disulfide, benzene, and other non-polar organic solvents
• Vapor Pressure: 0.0254 mmHg at 25°C

1.3 Unique Chemical Properties

• Pyrophoricity:
  • Spontaneously ignites in air at temperatures above 30°C (86°F)
• Chemiluminescence:
  • Emits a faint greenish-white glow in the dark due to slow oxidation
• High Reactivity:
  • Reacts violently with oxidizing agents and halogens
• Allotropism:
  • Can transform into more stable red phosphorus at elevated temperatures

2.Production Technology

2.1 Electric Furnace Process

• Raw Materials:
  • Phosphate rock (fluorapatite: Ca₅(PO₄)₃F)
  • Coke or petroleum coke (carbon source)
  • Silica sand (SiO₂)
• Process Steps:
  • Feeding: Raw materials are continuously fed into an electric arc furnace
  • Heating: The mixture is heated to 1200-1500°C using electric arc heating
  • Reduction: Carbon reduces phosphate to elemental phosphorus
  • Slag Formation: Silica combines with calcium to form calcium silicate slag
  • Vapor Collection: Phosphorus vapor is collected and condensed under water
• Chemical Reactions:
  • Primary: 2Ca₃(PO₄)₂ + 6SiO₂ + 10C → P₄ + 6CaSiO₃ + 10CO
  • Secondary: Ca₅(PO₄)₃F + 9SiO₂ + 15C → 3P₄ + 9CaSiO₃ + CaF₂ + 15CO

2.2 Alternative Production Methods

• Wet Process:
  • Historical method using sulfuric acid treatment of phosphate rock
• Blast Furnace:
  • Less common method using coke-fired blast furnaces
• Microwave-Assisted:
  • Emerging technology for small-scale production

3.Applications and Uses

3.1 Industrial Applications

• Phosphoric Acid Production: Primary use for manufacturing high-purity thermal phosphoric acid
  • Food-grade applications (soft drinks, processed foods)
  • Pharmaceutical intermediates
  • Electronic-grade chemicals
• Chemical Intermediates:
  • Phosphorus trichloride (PCl₃) for pesticide production
  • Phosphorus pentachloride (PCl₅) for pharmaceutical synthesis
  • Phosphorus pentasulfide (P₂S₅) for lubricant additives
• Specialty Chemicals:
  • Flame retardants
  • Plasticizers
  • Metal treatment chemicals

3.2 Military Application

• Smoke Generation:
  • Primary military use for creating obscuring smoke screens
• Incendiary Effects:
  • Used in shells and grenades for igniting targets
• Marking and Illumination:
  • Tracer rounds and battlefield illumination
• Anti-Material:
  • Destruction of equipment and ammunition

4.Market Analysis

4.1 Market Dynamics

• Demand Drivers:
  • Growing food industry requiring phosphoric acid
  • Expanding pharmaceutical sector
  • Agricultural chemical production
• Supply Constraints:
  • High energy costs for electric furnace operations
  • Environmental regulations
  • Safety and handling requirements
• Price Trends:
  • Volatile due to energy costs and regulatory changes