phosphuric acid

I made the acid using HCL acid and the local stone. the by products are phosphuric acid (needing to be purified) and calcium carbonate (I think, its sold as plaster of paris).

Are there anybodies here that know how I may purify the acid?

In the laboratory, the calcium carbonate would be removed by passing the suspension through a filter paper.

What happened to the -Cl in the hydrochloric acid, though?

I don't know...