Refining & Grade Specs

Tungsten Refining Methods and Grade Specifications

The transformation of Tungsten concentrate into refined products suitable for industrial use requires specialized metallurgical and chemical processes. Tungsten is refined into 5 primary commercial forms, each serving specific end-use sectors.

Refining Processes

The primary refining and processing pathways for Tungsten include:

1. Gravity and magnetic separation
2. Alkaline pressure digestion
3. Ammonium paratungstate (APT) production
4. Hydrogen reduction to tungsten metal
5. Carburization to tungsten carbide

Product Forms and Grade Specifications

Refined Tungsten is available in the following commercial forms, each with specific purity requirements:

Quality Standards and Benchmarks

International standards for Tungsten products are established by organizations such as ASTM International and various national standards bodies. Pricing is referenced against Fastmarkets/Platts assessments. These standards define minimum purity levels, acceptable impurity limits, and testing methodologies that facilitate international trade.

Refining Capacity and Geography

Global refining capacity for Tungsten is concentrated in a limited number of countries. China controls approximately 82% of primary production and plays a significant role in downstream refining. Efforts to diversify refining capacity are a key priority for governments seeking to reduce supply chain dependencies, particularly in the cemented carbide cutting tools sector.