Extraction of magnesium hydroxide from boron sludge by alkali fusion and ammonia leaching: process optimization and application

As an innovative extraction technology, the combined alkali fusion and ammonia leaching method effectively improves the efficiency and purity of magnesium hydroxide extracted from boron mud, and provides a new way for resource recycling and the development of environmentally friendly materials.

Overview of Boron Mud

Source: solid waste in the production process of borates.

Ingredients: Contains elements such as magnesium, silicon, aluminum, and iron.

Extraction Method

Alkali fusion pretreatment: mixed with alkaline substances, treated at high temperature to destroy the mineral structure.

Ammonia leaching: mixed with ammonia solution, magnesium ions react with hydroxide ions to form magnesium hydroxide precipitate.

Filtration and washing: solid-liquid separation, multiple washing to remove impurities.

Drying and calcination: drying to constant weight, optional calcination to obtain magnesium oxide.

Key parameters

Alkali fusion conditions: temperature, alkaline-earth ratio, melting time.

Ammonia leaching conditions: ammonia concentration, time, temperature.

Advantages

Improve the extraction rate: alkali fusion treatment increases the solubility of magnesium ions.

Improve purity: magnesium hydroxide precipitate is easy to separate and improve purity.

Application

Magnesium hydroxide is used as a raw material in flame retardants, environmentally friendly materials and other fields.

Experimental results

The magnesium hydroxide product obtained under the optimized conditions has a high purity.

The combined alkali fusion and ammonia leaching method effectively improves the efficiency and quality of extracting magnesium hydroxide from boron mud, and is a sustainable method for effective resource utilization.