Preparation of nano-iron oxide red pigment powders by use of cyanided tailings.
On one hand, cyanided tailings are one kind of pollutants. On the other hand, they contain a lot of valuable elements. So utilization of them can bring social and environmental benefits. In this paper, cyanided tailings were used to prepare nano-iron oxide red pigment powders by an ammonia process with urea as precipitant. At first, cyanided tailings were oxidized by nitric acid. Then, the oxidizing mixture was separated into solid and liquid parts. The liquid mixture was reduced by scrap iron and the impurity of it was removed by use of NH3.H2O. Then, the seed crystal of gamma-FeOOH was obtained, when the pure liquid reacted with ammonia liquid at the selected experimental conditions. At last, nano-iron oxide red pigment powders were prepared. The structure, morphology and size distribution of seed crystal and iron oxide red were characterized systematically by means of X-ray diffraction (XRD), transmission electron microscope (TEM) and laser particle size analyzer (LPSA). The results revealed that typical iron oxide nanoparticles were alpha-Fe2O3 with particle size of 50-70 nm. Furthermore, the factors that affected the hue and quality of the seed crystal and iron oxide red pigment were also discussed.
Dengxin
Li
L
College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Songjiang District, Shanghai 201620, China. lidengxin@dhu.edu.cn
Guolong
Gao
G
Fanling
Meng
M
Chong
Ji
J
D000641:Ammonia / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D003486:Cyanides / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D053758:Nanoparticles / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry; D010084:Oxidation-Reduction; D011208:Powders; D013696:Temperature; D014508:Urea / Q000737:chemistry*
D004396:Coloring Agents; D003486:Cyanides; D005290:Ferric Compounds; D005296:Ferrous Compounds; D007220:Industrial Waste; D011208:Powders; C000499:ferric oxide; C020748:ferrous sulfate; D017942:Nitric Acid; D000641:Ammonia; D014508:Urea