Effect of hydration method on preparation of high-purity magnesium hydroxide from microcrystalline magnesite

Microcrystalline magnesite is a mineral resource rich in magnesium. Through a specific hydration process, high-purity magnesium hydroxide (Mg(OH)₂) can be prepared. Due to its excellent purity, whiteness and dispersibility, magnesium hydroxide has shown wide application potential in many fields such as flame retardants, medicine, food additives, cosmetics and environmentally friendly materials. This paper will explore the influence of different hydration methods on the preparation of high-purity magnesium hydroxide from microcrystalline magnesite, and provide theoretical support for optimizing the production process.

Classification of hydration methods and their influence

Dry steam hydration

The hydration reaction carried out in a dry environment usually presents a hexagonal sheet or granular structure. Under dry steam conditions, the reaction between magnesium ions and water molecules is relatively mild, and the crystal structure of the formed magnesium hydroxide is relatively dense. However, its crystallinity may not be as good as that of the wet steam hydration product.

Wet steam hydration

The hydration reaction carried out in an environment with high humidity usually has a better crystal morphology, which is hexagonal flakes. Under wet steam conditions, the reaction between magnesium ions and water molecules is more sufficient, which is conducive to the formation of a larger and regular crystal structure.

Effect of hydration conditions on products

Product morphology

Wet steam hydration is more conducive to the formation of hexagonal magnesium hydroxide crystals. This form of magnesium hydroxide has a larger specific surface area and better dispersibility, which is crucial to improving the application performance of the material.

Purity

Chemical analysis shows that whether it is dry steam or wet steam hydration, the MgO content after 2 hours of heat preservation at 500℃ to remove the loss of ignition can reach about 99%. This shows that microcrystalline magnesite is an ideal raw material for preparing high-purity magnesium hydroxide.

Crystallinity

Under wet steam hydration conditions, the crystallinity of magnesium hydroxide is high, which is closely related to the full contact and reaction between magnesium ions and water molecules during the reaction process.

The choice of hydration method has a significant effect on the product morphology, purity and crystallinity of high-purity magnesium hydroxide prepared from microcrystalline magnesite. Compared with dry steam hydration, wet steam hydration can produce magnesium hydroxide products with better crystallinity and better morphology. Therefore, in industrial production, it is crucial to choose a suitable hydration method according to the specific application requirements of magnesium hydroxide.

By studying the different hydration modes of microcrystalline magnesite, we can have a deeper understanding of the influence of hydration conditions on the performance of magnesium hydroxide products, thus providing a theoretical basis for optimizing production processes and improving product quality. In practical applications, by precisely controlling the hydration process, high-purity magnesium hydroxide products that meet specific needs can be prepared, promoting their widespread application in multiple industries.