Abstract:The metal fluoride was induced precipitated from the stainless steel pickling bath, which could be expected to recovery valuable metals and recycle acid pickle. Measures such as XRD, SEM and laser particle analyzer were used for detect the precipitant. The capacity of crystal seed, temperature and HF content of pickling bath were investigated to optimize the deposition conditions. The result show that the deposit was the mixture of FeF3·3H2O and CrF3·3H2O. There was no Ni sediment found during the test. The effects of temperature, HF concentration and seed capacity on metal deposit were studied. It was found that the quantity of metals precipitation was more with the condition of lower temperature, higher HF content, the seed capacity had no effect on it.