What is gangue? Md. Saifur Rahman During metal extraction from ores, some other materials besides the ore are mixed with the ores which are known as metal impurities. You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?