Determination of metallic nickel in reducing products of nickel laterite ore by inductively coupled plasma atomic emission spectrometry after bromine-methanol extraction
LI Bo，WANG Hua*，WEI Yong-gang
Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction Ministry of Education，Kunming University of Science and Technology，Kunming 650093，China
Abstract：The metallic nickel in reducing products of nickel laterite ore was extracted by bromine-methanol. After filtering and separating the insoluble residue, the filtrate was evaporated to dryness. The residual was then dissolved in hydrochloric acid. The 231.604 nm was selected as analytical spectral line of nickel. The content of nickel in solution was determined by inductively coupled plasma atomic emission spectrometry under optimal instrumental conditions. Hence, the content of metallic nickel could be calculated. The influence of sample size, extraction time, bromine concentration, dosage of bromine-methanol and interference elements on determination results was studied. Moreover, the sample analysis and recovery test were performed. The results showed that, when the sample size was smaller than 0.1 mm, and the metallic nickel was extracted with 100 mL of 5 % (V/V) bromine-methanol for 90 min, the determination results were best. Under this condition, some other active metal elements such as magnesium, aluminum and iron could be also extracted. Since their spectral lines would be overlapped with that of nickel, the determination of nickel would be affected. However, the interference could be eliminated by background correction method. The proposed method was applied to the determination of metallic nickel in reducing products of nickel laterite ore. The relative standard deviations (RSD) of determination results were in the range of 0.96 %-5.9 %. The recoveries of standard addition were 97.8 %-103.8 %.
