Development and use of iron oxide pigments
In all kinds of pigments, iron oxide pigment production second only to titanium dioxide, is an upscale compound dye, is the second large amount of inorganic pigments, is the first large colour pigments. Iron oxide pigment colors, wide color spectrum, high hiding power, stain, primary colors red, yellow and black three through leveling can also be orange, Brown, green and other composite pigment chromatography. Iron oxide pigments have very good resistance to light, weathering, acid, alkali and solvent resistance, but also has toxic characteristics, widely used in building materials, paint, ink, plastic, ceramics, paper, magnetic recording materials and other industries.
By by-product ferrous sulfate as raw materials, iron oxide can produce many kinds of products, the best way of dealing with ferrous sulfate.
Common iron oxide pigments
Method of calcined to produce iron oxide Red
United States market, brand iron oxide about 80, about 20 of which were burning method Copperas red Japan calcination yield the world's largest iron oxide, an annual output of about 200,000 tons, but the product is mainly used as a magnetic material. Mainly produced by calcination method, but its low quality, not widely used, quality and popular method of nitric acid iron as used relatively far away.
World of iron oxide pigments, 60% for building material, 30% for paint. The two uses of iron oxides are required to have a good sense of color and dispersion, ferric oxide is also used for building materials must have high colouring strength (low tinting strength can increase the pigment added, impact strength and other properties. )。 Calcination Copperas red iron oxide particles produced by large, dark in color and coloring
Production by liquid-phase oxidation of iron oxide and iron oxide yellow
With caustic soda (or ammonia) in the and ferrous sulfate generated hydrogen oxidation Asia iron, to air oxidation hydrogen oxidation Asia iron business Crystal species, in Crystal species exists Xia with air oxidation ferrous sulfate, reaction process in the continuous drops added ferrous sulfate and alkali (or ammonia), keep must of Asia iron concentration and PH value, through on shade progress of control can get from light to dark series hue of iron oxide. Differs from the process red iron oxide and iron oxide yellow Crystal preparation conditions, iron under acidic conditions Topaz species, tiehongjing species under alkaline conditions. Method of liquid-phase oxidation with air to produce 1 ton of iron oxide about FERROUS SULFATE HEPTAHYDRATE 3.5~4 ton, 30% of 3 tons of caustic soda or ammonia to 0.45 tons.