The wet process uses ferrous sulfate or ferrous nitrate, ferric sulfate, and ferric nitrate as raw materials, and adopts a red iron oxide production method of first preparing crystal seeds and then oxidizing to prepare iron red. The raw materials used can be either ferrous sulfate, ferrous nitrate solid raw materials, or an aqueous solution containing ferrous sulfate, ferrous nitrate, ferric sulfate, and ferric nitrate. The neutralizing agent used can be either iron sheet, iron filings, or alkali or ammonia.
In recent years, based on the comprehensive utilization of industrial waste, a method of preparing iron oxide red industrial pigments with titanium dioxide by-product ferrous sulfate or ferric sulfate solution, and using steel mill pickling waste acid or waste water as raw materials, has been developed. All belong to the category of wet process. The neutralizing agent used is still iron sheet, iron filings, alkali or ammonia.
The advantage of the wet process is that the obtained product has excellent quality and performance, and different types of serialized iron oxide red products can be prepared. The disadvantage is that the process flow is long, the energy consumption of the production process is high, a large amount of acidic wastewater is produced, and there is currently no effective comprehensive utilization of acidic wastewater.
