Preparation method and process of iron oxide red

Transparent iron oxide pigment is an iron oxide pigment with a particle size less than 100nm, which is called transparent iron oxide because of its good transparency in transparent media. The added value of its products is much higher than that of ordinary iron oxide.

Because of its small primary particle size, the iron pigment has different optical effects and characteristics from ordinary iron oxide pigments, in addition, the iron pigment also has good weather resistance, light resistance, magnetism, and excellent absorption and shielding effect on ultraviolet rays.

At present, iron oxide pigments are most used in automotive paint and wood paint, but also in architectural coatings, industrial coatings, as well as plastics, nylon, rubber, printing ink, art coatings, powder coatings and other fields have been widely used.

Iron oxide red is the main color of iron oxide pigments with good pigment quality and a wide range of applications. There are two methods for producing iron oxide red: dry method and wet method. Today we will take a look at its preparation method and process.

(1) Preparation of ferric sulfate

It includes the reaction of red slag with sulfuric acid after making sulfuric acid from pyrite, and adding by-product ferrous sulfate titanium dioxide according to the iron content of red slag. The specific implementation steps are as follows: 1.2-1.6 tons of pyrite red slag and 1.4-1.8 tons of concentrated sulfuric acid with a mass concentration of 93% are put into the mixing tank to stir evenly, and then 0.8-1.2 cubic meters of prepared titanium dioxide by-product ferrous sulfate aqueous solution is slowly added to the mixing tank, so that the materials in the mixing tank are rapidly released and there is a slight feeling of shaking. After the reaction, the material is heated and dried in a belt fluidized bed. The temperature of the fluidized bed is controlled at 75-90 degrees, and the temperature of the hot air is controlled at 350-400 degrees. After 1-3 hours of heating, the material is sent to the calcining process.

(2) Calcination

That is, the iron oxide red material of the previous process is oxidized and roasted, and the kiln head temperature is required to be controlled at 400-550 degrees, the kiln tail temperature is controlled at 350-400 degrees, and the kiln speed is required to be 3-5 minutes per revolution. After roasting, the material is cooled to room temperature by the cooling roller and enters the next process. Ammonium sulfite byproduct is prepared after the calcined tail gas is absorbed by liquid ammonia.

(3) Particle crushing and soluble salt removal

That is, the iron oxide red material of the previous process is ground with pebble and water wet until the fineness reaches 325 mesh, the pass rate reaches more than 90%, and the slurry is obtained. Put the slurry into the settling bucket, settle naturally for 1 hour, and then pour the supernatant in the bucket into the plate frame for washing to remove the soluble salt. The electrical conductivity of the water to be washed can reach more than 5000s/cm, and the next step can be started. The large particles deposited at the bottom of the barrel are returned to the pebble grinding process for re-grinding to ensure that there are no large particles.

(4) Drying and crushing

The qualified iron oxide red material after cleaning is put into a rapid dryer for dehydration. The material is required to stay in the flash for 2-5 seconds, the temperature after the flash is 450-500 degrees, the material is crushed into the air flow grinder, the fineness is required to reach 325 mesh, the pass rate is above 99.7%, and the moisture is less than 0.3%.

The above is the preparation method and process of iron oxide red, we must be careful to pay attention to the operation to avoid mistakes.

Whether you are looking for a high quality pigment for your concrete coloring or need a reliable and durable material to meet your plastic or paint coating needs, our iron oxide range is the perfect choice for you.

We provide free samples, you can choose 300g or 500g, you can also choose a variety of colors, according to your needs to send samples！Contact us today to learn more about our products and how they can benefit your business！