METHOD OF SEPARATING PLATINUM AND RHODIUM IN HYDROCHLORIC ACID SOLUTIONS Russian patent published in 2001 - IPC

FIELD: precious metal technologies. SUBSTANCE: separation is accomplished with assistance of high-basic anionites as sorbents. Before sorption, hydrochloric acid solution is treated with ammonium chloride solution to partially precipitate platinum compounds. Sorption is carried out by filtration through sorbent layer until anionite is saturated with platinum ions. Sorbent is then washed with 5-7 M hydrochloric acid solution. Triply washed sorbent is regenerated with hydrazine hydrate solution, after which kept for 2-2.5 h at 350-400 C in reductive atmosphere and then burned at 950-1000 C. Ammonium chloride solution is used in amounts high enough to maintain platinum-rhodium ratio in solution equal to 1:2. EFFECT: enabled recovery of high-purity rhodium compounds and precipitate metal, reduced platinum loss and consumption of sorbent, simplified procedure. 2 cl, 1 tbl