1. a person or company that purifies raw materials, especially oil or metals, by removing impurities

Examples

• The oil refiner processes crude oil into gasoline and other products.
• Sugar refiners remove molasses and other impurities from raw sugar.
• The metal refiner uses heat to separate pure gold from ore.
• Large refiners operate complex facilities with multiple processing units.
• The petroleum refiner announced plans to expand its operations.
• Small-scale refiners often specialize in precious metals.