Titanium Products Production Process

Stage 1: Ore Extraction and Concentration

Foundation of Titanium Production

Titanium is the fourth most abundant structural metal on Earth. Its primary ores are rutile (approximately 95% TiO₂) and ilmenite (FeTiO₃, containing 50-65% TiO₂). The initial step involves mining, typically open-pit, followed by gravity separation and other physical methods to concentrate the titanium minerals and remove waste materials.

Creating the Intermediate Compound

Before titanium metal can be produced, the concentrated titanium dioxide (TiO₂) must be converted into titanium tetrachloride (TiCl₄). This process, often referred to as carbo-chlorination, involves reacting the oxide ores with chlorine gas in a fluidized bed of petroleum coke at high temperatures (850-1000°C).

The raw TiCl₄ gas is then cooled, liquefied, and subjected to fractional distillation to remove impurities, ensuring a purity exceeding 99.9%.

Transforming TiCl₄ into Titanium Metal

The most widely adopted method for producing titanium metal from TiCl₄ is the Kroll Process. This batch process involves reducing purified TiCl₄ with molten magnesium (Mg) in an inert argon atmosphere at temperatures between 800-1000°C.

This reaction yields titanium in the form of a highly porous material known as titanium sponge. The magnesium chloride (MgCl₂) is recycled to recover magnesium and chlorine for reuse.

Creating High-Quality Titanium Ingots

• Vacuum Arc Remelting (VAR): The primary method for manufacturing titanium alloys. It involves melting a cylindrical electrode in a vacuum or inert argon environment within a water-cooled copper crucible.

• Electron Beam Cold Hearth Remelting (EBCHR): An advanced consolidation process that addresses limitations of VAR, particularly in removing high-density and low-density inclusions.

Shaping Titanium into Usable Forms

Forging: Involves applying thermal and mechanical energy to titanium billets or ingots to change their shape while in a solid state. Forging is crucial for developing the desired microstructure.

Casting: Involves heating titanium until it is molten and then pouring it into a mold. This method is generally less costly and can produce near-net-shape components.

Optimizing Mechanical Properties

• Annealing: Alters the chemical and physical properties to improve ductility, fracture toughness, and thermal stability.

• Stress Relieving: Reduces residual stresses that develop during fabrication processes like machining or welding.

• Solution Treating and Aging: Used to achieve the highest strength in titanium alloys through a sequence of heating, quenching, and aging.