 Of the 218 tonnes of platinum sold in 2014 , 98 tonnes were used for vehicle emissions control devices ( 45 % ) , 74 @.@ 7 tonnes for jewelry ( 34 % ) , 20 @.@ 0 tonnes for chemical production and petroleum refining ( 9 @.@ 2 % ) , and 5 @.@ 85 tonnes for electrical applications such as hard disk drives ( 2 @.@ 7 % ) . The remaining 28 @.@ 9 tonnes went to various other minor applications , such as medicine and biomedicine , glassmaking equipment , investment , electrodes , anticancer drugs , oxygen sensors , spark plugs and turbine engines . 
