Preparation Of Ammonium Iron Blue From Titanium White By-product FeSO₄ And Ammonia Method Iron Oxide Pigments Waste Liquid

Every year titanium dioxide manufacturing industry produces a variety of by-product Fe SO4·7H2O. Producing 1t titanium dioxide will emit 3.5~4t Fe SO4·7H2O. If they cannot be made full use of, a large number of resources will be wasted. Using ammonia method to prepare iron series pigments is one of the ways to the ferrous sulfate utilization. There have been many relevant researches. But the process can produce a large amount of ammonium sulfate waste liquid, which limits its widely application in industry. Ammonium iron blue is a kind of traditional blue paint based on cyano complex. Its stable chemical properties make it widely used in coatings and inks industry. Raw material for the preparation of ammonium iron blue is iron salt, ammonium salt, and cyanide. Visibly, the preparation of ammonium iron blue provides the reference data and theoretical guidance for utilization of Fe SO4 and(NH4)2SO4. The main contents and results of the research are as follows:(1)Used the Fe SO4 by-product of producing titanium dioxide and ammonium sulfate waste liquid from the production of iron oxide yellow or iron oxide red to prepare ammonium iron blue. The NH4+ content of ammonium iron blue is higher, its color is brighter, so this paper explored the factors of Fe SO4 concentration,(NH4)2SO4 concentration, p H of(NH4)2SO4 and Fe SO4 mixture, reaction temperature, boiled time in acid, oxidizing time and oxidant content on the influence of the NH4+ content of ammonium iron blue. The results showed that while the concentration of(NH4)2SO4, Fe SO4 and Na4Fe(CN)6 were 0.2 mol/L, adjusted the p H of mix solution of(NH4)2SO4 and Fe SO4 to 3, kept the reaction temperature at 70℃ and the boiling temperature at 90℃, boiled 2 hours in sulfuric acid, and the oxidation temperature was 60℃, the NH4+ content of the ammonium iron blue could reach 3.11%. Moreover,its color was bright; particle size was average,within 50 ~ 100 nm. The quality was beyond the industry standard HG/T 3001-1999.The dispersion of the ammonium iron blue prepared in above method was poorer. Modified the ammonium iron blue through adding sodium hexametaphosphate, sodium silicate and sodium dodecyl sulfate. We found that sodium hexameta- phosphate′s effect was the best.(2)The ferric sulfate and sulfate ammonium emitted in the process of ammonia method iron oxide yellow or red to produce ammonium iron blue were studied. By adjusting the reaction temperature, concentration of Fe2(SO4)3,(NH4)2SO4 concentration, p H of(NH4)2SO4 and Fe2(SO4)3 mixture, reaction time, investigate the influence of the NH4+ content on ammonium iron blue properties. Ammonium iron blue prepared in different time was characterized by XRD and SEM. The results showed that when the concentration of Na4Fe(CN)6,(NH4)2SO4 and Fe2(SO4)3 were respectively 0.4 and 0.2mol/L, p H of(NH4)2SO4 and Fe2(SO4)3 mixture was 1.7, reaction time was 40 min, the NH4+ content on ammonium iron blue ccould reach 2.89%.In addition, under the same conditions,compared with the use of K4Fe(CN)6 and Na4Fe(CN)6 in the same concentration to prepare ammonium iron blue. The results showed the NH4+ content of the ammonium iron blue prepared with Na4Fe(CN)6 was higher. And its color was brighter.(3)Compared to the two ammonium iron blue prepared by the above two methods. Through characterization of XRD, SEM and FTIR, we can see the composition of the two ammonium iron blue was the same, but the morphology, color and particle size were different.