Zone refining has enabled the production of semiconductors with impurity levels low enough to revolutionize microelectronics.

She stirred refiner's syrup into the batter until it gave the cake a warm, caramel color.

They re-refined the used engine oil to restore its quality.

Each time new impurities are discovered, the chemist re-refines the sample to ensure its purity.

The plant is re-refining used motor oil to meet new environmental standards.

After testing revealed impurities, the engineers decided to re-refine the alloy before production.

The new grain refiners at the mill improved flour quality within weeks.

The metallurgist added a grain refiner to the molten aluminum to ensure a fine, uniform cast microstructure.

Advances in catalysis have significantly improved efficiency and reduced emissions in oil refining plants worldwide.

The designer presented an ultra-refined collection that blurred the line between art and fashion.