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.