Experimental Study On Preparation Of Iron Oxide Red Pigment By Purification Of Fengning Specularite Ore

As one of the most important iron oxide pigments,iron oxide red has the most using and demand.Most iron oxide red is synthesized,which was complicated,difficult and costed.Specularite is cheap and stable,but it lacks high value products.Its crystal form isα-Fe₂O₃,as material processing into iron oxide red has more economic value,but also can expand the preparation process.The preparation and properties of iron oxide red was carried out.Since color and dispersion are two important indicators,the test focused on improving the color and dispersion of iron oxide red.The main results are as follows:According to the properties of ore,the process of separation-ultrafine grinding was carried out.The final iron oxide red product has 96.50%Fe₂O₃ content and a median diameter of 1.87μm.The properties of pigments are up to GB/T 1863-2008 standard,but the color is poor.Among them,Fe₂O₃ content,relative coloring power,volatiles and other indicators reach the level one standard.The prepared iron oxide red product was mixed with 60%sulfuric acid at a mass ratio of 2:6 and roasted at 800℃for 120min.The color was positive red.Meanwhile,the roasting process of iron oxide red was analyzed.The results showed that the flake iron oxide red dissolved and recrystallized into short rod shape in the roasting process of sulfuric acid.The change of particle morphology directly affected the absorption of visible wavelength light of the product,and the color was changed.In addition,the growth degree of the recrystallized iron oxide red also affects the color of the product.The surface modification of iron oxide red was carried out to improve its dispersibility.Under the optimum conditions of polyacrylic acid dosage,modification temperature and time,the settling time of iron oxide red in water reaches 32.52h,D50 is1.10μm,and the dispersion is more stable and uniform.The modification mechanism analysis shows that the absolute value of electric potential on the surface of iron oxide red particles increases by physical and chemical adsorption of polyacrylic acid,which increases the electrostatic repulsion between the particles and improves the dispersion.Figure 35;Table 19;Reference 53...