Tungsten extraction rate for the world and Verhulst function fits to the data.
L. David Roper
http://arts.bev.net/RoperLDavid/
21 December 2007
Tungsten is used to make high-strength steel alloys. The graph below shows the tin extraction data for the world and two Verhulst function fits to the data in order to extrapolate into the future.
Tungsten extraction rate for the world and Verhulst function fits to the data.
The red curve is a fit with total amount to be extracted of 9x106 tonnes and the blue curve is for a fit with twice that amount.