How To Make Sinker Molds Safe Physics Help?

Physics help? - how to make sinker molds safe

I had many problems with this issue of physics. I think this is the latent heat. Can someone tell me how can I do? I'm so confused!

The problem:
How much energy required to melt a 225 kg of lead, so he used a lead weight for fishing? The sample has an initial temperature of 27.3 degrees Celsius. and poured directly into the mold after it has melted.

I'm not sure if this has anything to do with the problem, but if it helps me to know that flying the specific performance of the head 1.28X10 2 ^ J / kg (degCelcius). I'm really confused, any help is appreciated!