Quality First, Precise Manufacturing. Our leading products have crushing equipment, sand making equipment, mobile crusher, etc., Each type of product is with complete specifications. All products have passed ISO9001, CE and GOST international quality system certification. Inquiry Online For More. Message Online Chat. Gold mining in South Africa. South Africa is a world leader in the gold mining industry. We have been doing gold mining for more than a century and our mines are the deepest in the world. Until 2010 we were the leading producer of gold in the world. Gold is a lustrous, precious metal which has a very high conductivity. QUESTIONS Rock Crushers. The size requirement of the primary rock crusher is a function of grizzly openings, ore chute configuration, required throughput, ore moisture, and other factors. Usually, primary crushers are sized by the ability to accept the largest expected ore fragment.