Cockburn Cement Pty, located near Perth, Western Australia, is a subsidiary of The Rugby Cement Group. After various expansions, it is now capable of producing 3000 tpd of Portland cement and 1500 tpd of quicklime. Because of the shortage and variable quality of onshore limestone, at an early stage in Company development it was thought prudent to augment the supply of limestone from the quarries surrounding the works. This was achieved by using sea-dredged shell sand from two sand banks just off-shore in the Indian Ocean. The blend of limestone and sea sand was used successfully in the cement raw mix and when it was decided to commence lime production in 1973, quicklime was made by feeding the shell sand directly to one of the long, wet cement kilns with modified feeding and product transport arrangements.