Complex sentence: Kal'makyr represents one of the largest copper reserve in Uzbekistan and in the world having estimated reserves of 2.5 billion tonnes of ore grading 0.38% copper and 40 million oz of gold.
Split into simpler sentences: Kal'makyr represents one of the largest copper reserves in Uzbekistan and the world. It has estimated reserves of 2.5 billion tonnes of ore grading 0.38% copper and 40 million oz of gold.