Decomposition of iron, cobalt, nickel, and copper formates

Conclusions

Investigations have shown that the decomposition of metallic formates is accompanied by a loosening of the structure of their crystals, the rate of the process depending on the nature of the metals. In the stages of decomposition the crystals acquire a porous, spongy structure and disintegrate under the action of gases being evolved and internal stresses being generated. Under these conditions the specific surfaces of specimens rapidly grow. The mean particle size of the end products of the reaction is 0.1–0.3μ, with a specific surface of about 60 m²/g. Exceptions are nickel and copper, whose particles have a strong tendency to sinter together, with the formation of agglomerates. X-ray studies have established that at various stages of the thermal decomposition process the intensities of reflections characterizing the starting salts change, and new reflections appear, indicating the formation of metallic phases in finely divided form. The method of thermal decomposition of metallic formates is suitable for the preparation of very fine powders of pure metals, from which various sintered materials can be produced.