You need to reduce AgCl into Ag. On small scale (20-30g) I did it with Zn and diluted HCl: Add HCl and water into AgCl. Drop Zn wire or small pieces. Zn produces H2, which reduces AgCl. Precipitate turns from white into grey. It takes several days. It probably will not work for large scale reactor. Glucose and other reducing agents may do the job (sometimes in ammonia/alkaline solution).