China Nonferrous Metallurgy

Some batches of the incoming copper raw material of a smelter in Yunnan Province contain resin powder. As resin has good acid and alkali resistance, it barely reacts with any acid and alkali solvents, thus, when the acid dissolution iodometry is adopted to measure the Cu content in the resin-bearing copper raw material, such problems exist as incomplete dissolution of the sample, repeatability and accuracy of the analysis results unable to meet the requirement. In this paper, the sample is first subject to solidification at 200℃, carbonization at 500℃ and ashing at 900℃, followed by assay and analysis using the acid dissolution iodometry. The test results show that under strictly controlled ashing temperature and time, the resin structure in the sample is completely broken, effectively avoiding the incomplete dissolution of the sample; the relative standard deviation (RSD, n=5) of the measured result is 0.20%-0.41%, the relative error (RE) is 0.06%-0.27% and the standard recovery is 99.01%-101.16%, indicating that the method results in good precision and accuracy and high recovery, thus, it can be used to measure the Cu content in resin-bearing copper raw material.