About 50 kinds of tin minerals are known by human. Tin ore mainly exists as cassiterite, other commonly-seen tin minerals includes stannite, franckeite, herzenbergite, incaite, cylindrite, nordenskildine and thoreaulite, etc. The average tin ore grade is less than 1%, alluvial tin grading 0.01%-0.1%. However, the tin concentrate grade of 40% is required, meaning the enrichment of hundreds or thousands times. Targeting at the refractory tin ore, low grade tin concentrate is obtained and it has to be further extracted by special metallurgy process.

Reduction smelting is the dominant process to extract tin metal from tin concentrate. Metalcess suggest electrical furnace for tin smelting because of its relatively low cost, short process and smart recycling of iron.