Preparation of nano-sized flaky magnesium hydroxide from magnesite tailings: process optimization and application prospects

Under the dual demands of comprehensive utilization of industrial by-products and environmental protection, the high-value utilization of magnesite tailings has become a research hotspot. As a material with wide application potential, the optimization of its preparation method is of great significance to improve the utilization value of magnesite tailings. This paper will explore how to prepare nano-scale flaky magnesium hydroxide from magnesite tailings by optimizing the process and analyze its application prospects.

Optimized preparation process

Raw material preparation:

Magnesite tailings: ｓｅｌｅｃｔ magnesium-rich magnesite tailings as the main raw material to ensure its purity and activity.

Process flow:

Calcination: Calcine magnesite tailings at high temperature to remove volatile impurities and activate the material.

Acidification: The calcined material is reacted with sulfuric acid to prepare a magnesium sulfate solution.

Precipitation: By controlling the pH value, magnesium ions react with hydroxide ions to form magnesium hydroxide precipitates.

Filtration and washing: Vacuum filtration technology is used to improve filtration efficiency and product purity.

Drying: Low-temperature drying technology is used to avoid the decomposition of magnesium hydroxide and obtain nano-scale flaky magnesium hydroxide powder.

Control of key factors

Reaction conditions:

pH value: The pH value of the reaction system is precisely controlled at 5-6 to promote the precipitation of magnesium hydroxide.

Temperature: The reaction temperature is controlled at about 80°C to accelerate the reaction rate.

Raw material quality:

Tailing purity: High-purity magnesite tailings are conducive to improving the quality of the final product.

Post-treatment process:

Filtration efficiency: Ensure that the precipitate is filtered and washed thoroughly to remove residual sulfate and other soluble impurities.

Drying technology: Low-temperature drying technology is used to maintain the nano-scale flaky structure of magnesium hydroxide.

Application of characterization technology

Morphology analysis:

SEM: Observe the morphology and particle size distribution of magnesium hydroxide powder to evaluate its dispersibility and morphology.

TEM: Analyze the microstructure of magnesium hydroxide powder to ensure its nano-scale flaky characteristics.

Composition analysis:

XRD: Analyze the crystal structure of magnesium hydroxide powder to confirm its purity and phase composition.

Specific surface area analysis:

BET: Determine the specific surface area of magnesium hydroxide powder to evaluate its adsorption performance.

Nano-scale flaky magnesium hydroxide has a wide range of application prospects in flame retardants, catalysts, adsorbents, etc. due to its unique physical and chemical properties. By using magnesite tailings to prepare this material, it can not only improve the efficiency of resource utilization, but also reduce environmental pollution, achieving a win-win situation in economic and environmental benefits.