Original: Sodium hydroxide ( lye ) is used in industry as a strong base , potassium hydroxide is used in agriculture , and iron hydroxide minerals such as goethite and limonite have been used as low grade brown iron ore .
Simplified: Sodium hydroxide is used in industry as a strong base , potassium hydroxide is used in agriculture , and iron hydroxide minerals such as goethite and limonite have been used as iron ore .