Process for harmlessly producing iron oxide red pigments by alkaline circulation method

Abstract

The invention discloses a process for harmlessly producing iron oxide red pigments by an alkaline circulation method. The process includes the steps: 1 preparing ferrous sulfate solution; taking iron-containing minerals or iron-containing solid waste materials as raw materials; crushing the iron-containing minerals or the iron-containing solid waste materials to prepare iron-containing material powder, performing acid leaching on the obtained powder, mixing the acid leaching liquid and ammonia decomposition raffinate from iron oxide red mother liquor ammonia water recovery procedures in an acid leaching reactor according to the solid-liquid ratio of 1:(1-5), adding an appropriate amount of sulfuric acid for leaching, and transforming iron in the iron-containing minerals or the iron-containing solid waste materials into ferric sulfate and ferrous sulfate to enter a liquid phase. Acid leaching temperature is increased by the aid of reaction heat in the leaching process, steam flow for heating is omitted in the reaction process, and filtering and washing are performed after reaction. Production capacity is high, energy is saved, pollution is avoided, compared with a current iron oxidepigment industry, production efficiency and equipment production capacity are improved, production cost is correspondingly reduced, and the process has obvious technical progress and is effectively 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...

AI Technical Summary

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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