Can you use trisodium phosphate (TSP) to kill weeds?

Somehow I wound up with a bag of trisodium phosphate, and I’m wondering how I might put it to use. Can I spread it like salt on weeds, or will it in fact make them grow even faster because the phosphorus is one of the basic plant nutrients (NPK, or nitrogen-phosphorus-potassium)?

If not to kill weeds, what’s a good use for TSP?