Comprehensive utilization method of silicate minerals

Abstract

The invention discloses a comprehensive utilization method of silicate minerals. The method comprises the following steps: firstly decomposing silicate minerals by using sulfuric acid as a decomposing agent, and carrying out acid leaching of residues for preparation of white carbon black; sending an acidolysis solution into a magnesium sulfate heptahydrate crystallizer to prepare a magnesium sulfate heptahydrate product and an acidolysis solution obtained after separation of magnesium sulfate; mixing magnesium sulfate heptahydrate and water, adding an oxidizing agent, a pH regulator and an adsorbent to convert iron in the solution to a ferric hydroxide precipitate, filtering to obtain a pure magnesium sulfate solution, sending the magnesium sulfate solution into a magnesium sulfate monohydrate powder dedicated preparation system to prepare a feed-grade magnesium sulfate monohydrate product; separating an iron precipitate from the acidolysis solution by an oxidation-precipitation process, carrying out oxidation, carrying out a polymerization reaction, and solidifying to prepare a solid polymeric ferric sulfate product; and sending the acidolysis solution after separation of the iron precipitate to a follow-up process to prepare a magnesium compound. According to the invention, insufficiencies such as high energy consumption during present technical process of production, low product purity and the like are overcome; and there is no emission of ''three wastes (waste gas, waste water and industrial residue) '' during the production process, so as to minimize the influence on the environment.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of non-metallic ores and hydrometallurgy, and in particular relates to a comprehensive utilization method of silicate minerals (any one of serpentine ore, asbestos tailings and forsterite ore). Background technique [0002] Silicate minerals (any one of serpentine ore, asbestos tailings, and forsterite ore) are a kind of minerals whose main chemical composition is silicon and magnesium, accompanied by iron, aluminum, nickel, cobalt and other elements. non-metallic minerals. Among them, the grades of magnesium oxide and iron oxide are respectively between 34-45% and 4-10%. Magnesium compounds such as magnesium carbonate, magnesium hydroxide, magnesium oxide, and magnesium silicate can be prepared by using magnesium in silicate minerals, and iron compounds such as ferrous oxalate, high-purity iron oxide, and iron-based industrial pigments can be prepared by using iron in them . ...

AI Technical Summary

Problems solved by technology

However, the shortcomings of these processes are: low product purity, which cannot meet the quality requirements of feed additives, such as the direct method of sulfuric acid, etc.; poor product solubility, such as high-temperature dehydration; high energy consumption, such as bittern evaporation; operation With harsh equipment conditions, such as high temperature and high pressure method

Therefore, the description of the preparation process of crude magnesium sulfate monohydrate in this method does not meet the most basic characteristics of the spray drying method.

[0009] (3) The crude magnesium sulfate monohydrate produced in the drying tower needs to be further sent to the cooling tower for cooling and crystallization, which is not only complicated in process, but also does not meet the characteristics of spray drying

[0010] (4), the production method of magnesium sulfate monohydrate described in this method lacks the refining means of magnesium sulfate, so the magnesium sulfate monohydrate product of feed grade cannot be prepared

[0011] (5), due to the many process procedures and long drying time of this method, there are still shortcomings such as high energy consumption

[0018] The disadvantage of this process is that when preparing solid polymeric ferric sulfate powder, liquid polymeric ferric sulfate needs to be concentrated at 90-150°C. From the physical characteristics of polymeric ferric sulfate, it can be synthesized at a temperature greater than 50°C or Drying will have a significant impact on the basicity of polyferric sulfate. The higher the temperature, the lower the basicity or even lose it; secondly, this method does not propose a stable method for the basicity of polyferric sulfate; meanwhile, polyferric sulfate is a Heat-sensitive products are very sensitive to temperature conditions. Although this method proposes the idea of ​​preparing solid polyferric sulfate by spray drying, it does not provide the process conditions for preparing solid polyferric sulfate by spray drying, such as air inlet temperature, mixing temperature and outlet temperature. wind temperature etc.

The present invention proposes the method for preparing iron oxide red from serpentine and tailings thereof, and the defect that exists is: the serpentine acid hydrolysis solution is a multi-component system composed of metal sulfates such as magnesium, nickel, iron, aluminum, etc. Simply add lye directly to it to adjust the pH value to 3.0-4.0. Although the iron in it can be separated theoretically, the purity of the prepared iron oxide red precursor is not high due to the following reasons. One is the precipitation of Fe3+ The pH value of Al3+ precipitation is close to the pH value of Al3+ precipitation, and the iron precipitation process will cause aluminum co-precipitation; the second is affected by the concentration of lye, stirring speed, and lye drop speed, which will cause uneven dispersion of lye in the reaction system or The dispersion speed is slow, which leads to the local alkalinity of the reaction system is too strong, causing co-precipitation of magnesium and nickel. Once the precipitation of magnesium and nickel is formed, it is difficult to dissolve back into the system, thus entering the iron oxide red precursor; The prepared iron oxide red precursor has high chemical activity, and has strong adsorption to metal ions such as magnesium and nickel, so as to affect the purity of the iron oxide red precursor. Therefore, the method proposed in this invention is affected by the iron oxide red precursor. Due to the limitation of body purity, it is impossible to prepare high-purity iron oxide red products that can meet the needs of high-end fields such as electronics

[0032] In summary, the published patents cannot prepare iron oxide red industrial pigments that meet industrial requirements from silicate minerals

Images