A kind of harmless production process of iron oxide red pigment by alkali cycle method

Abstract

The invention discloses a process for harmlessly producing iron oxide red pigment by alkali circulation method, which comprises the following steps: Step 1: preparation of ferrous sulfate solution; using iron-containing minerals or iron-containing solid waste as raw materials; ferrous ore Iron-containing material powder is obtained by pulverizing iron-containing material or iron-containing solid waste, and then the gained powder is subjected to acid leaching, and in the acid-leaching reactor, the ammonium solution raffinate from iron oxide red mother liquor reclaiming ammonia water operation is by solid-to-liquid ratio 1: 1~5 are mixed, and an appropriate amount of sulfuric acid is added for leaching, so that the iron in iron-containing minerals or iron-containing solid waste is converted into ferric sulfate and ferrous sulfate and enters the liquid phase. The leaching process uses the reaction heat to increase the acid leaching temperature. The reaction process There is no need to heat through steam, and filter and wash after the reaction. The invention has large production capacity, energy saving and no pollution. Compared with the current iron oxide pigment industry, it not only improves the production efficiency and equipment production capacity, but also reduces the production cost correspondingly, and has obvious technical progress, which is well popularized.

Description

technical field [0001] The invention belongs to the technical field of inorganic pigment production equipment, and relates to a process for harmlessly producing iron oxide red pigment by alkali circulation method. Background technique [0002] Iron oxide red pigment is a very important inorganic color pigment with good pigment quality and wide application fields. The methods of producing iron oxide red are divided into dry method and wet method. The dry method mainly includes green vitriol (ie ferrous sulfate heptahydrate) calcining method, iron yellow calcining method, iron black calcining method, and hematite Mineral ore as raw material of natural iron oxide mineral ultra-fine crushing method, etc. Wet process mainly includes sulfate (i.e. ferrous sulfate or solution containing ferrous sulfate) method, nitrate (i.e. ferric nitrate, ferrous nitrate or solution containing ferric nitrate salt) method, mixed acid method; Different neutralizers used in the oxidation process c...

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Problems solved by technology

However, there is a problem that the concentration of ferrous sulfate in the oxidation process is high, which will affect the reaction rate.

At the same time, the reaction time is as long as 40~130 hours, which does not meet the process characteristics of ammonia neutralization method

Moreover, due to the high concentration of ferrous sulfate and long reaction time, the viscosity of the slurry system will increase in the middle and late stages of the oxidation reaction, which will affect the dispersion state of air in the system and promote the formation of black phases that affect product quality, making it difficult to manufacture Obtain high-quality iron oxide red products

The mother liquor is treated by evaporating and concentrating to obtain ammonium sulfate, which consumes a lot of energy and costs, and seriously affects economic benefits

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