Context: Zinc metal is produced using extractive metallurgy. After grinding the ore, froth flotation, which selectively separates minerals from gangue by taking advantage of differences in their hydrophobicity, is used to get an ore concentrate. This concentrate consists of about 50% zinc with the rest being sulfur (32%), iron (13%), and SiO
2 (5%). The composition of this is normally zinc sulfide (80% to 85%), iron sulfide (7.0% to 12%), lead sulfide (3.0% to 5.0%) silica (2.5% to 3.5%), and cadmium sulfide (0.35% to 0.41%).

Question: What is used to produce the metal zinc?
Answer: extractive metallurgy.

Question: What is froth flotation used for?
Answer: get an ore concentrate

Question: What is the first step in zinc metal production?
Answer: grinding the ore

Question: What percentage of the ore concentrate is zinc?
Answer: 50%

Question: What is used to eliminate the metal zinc?
Answer: Unanswerable

Question: What is froth flotation no longer used for?
Answer: Unanswerable

Question: What is the only step in zinc metal production?
Answer: Unanswerable

Question: What percentage of the s'more concentrate is zinc?
Answer: Unanswerable