MMD Mining Machinery, based in Derbyshire, makes machines that crush and grind rocks for mining companies. It manufactures equipment in South Africa and China as well as at its Derbyshire headquarters. The company has 14 service centres worldwide, which provide on-site servicing and advice to its clients. In the past two years growth has come from the expanding China office and foreign exchange gains related to doing business in Chinese yuan. International sales have risen 52% a year, from £15.3m in 2007 to £35.4m in 2009.