Preparation of cerium oxalate from spent iron–potassium catalyst for dehydrogenation of isoamylenes into isoprene

The cerium recovery in the oxalate form from spent iron–potassium catalyst for dehydrogenation of isoamylenes into isoprene was studied. The optimum conditions allowing preparation of the pure product with high degree of recovery were found. It was proved by X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, and X-ray fluorescence analysis that the product obtained by the precipitation was cerium oxalate decahydrate containing no less than 98 wt % main substance.