There are two main types of food -grade magnesium carbonate:
- Precision method
The precipitation method is the most commonly used method for the production of magnesium carbonate. The basic principle is to use magnesium sulfate and sodium carbonate to generate a complex decomposition reaction in the aqueous solution to generate magnesium carbonate precipitation. This method is simple, easy to control, and low in cost, but the purity of magnesium carbonate is not high and requires further refining.
The specific process process of the precipitation method is as follows:
Heat the magnesium sulfate solution and sodium carbonate solution to 80-90 ° C, respectively;
Add the magnesium sulfate solution to the sodium carbonate solution and stir it while adding it to fully react;
Settle the precipitation, separate the magnesium carbonate sedimentation;
Wash the magnesium carbonate with distilled water and remove impurities;
Dry the magnesium carbonate and get food -grade magnesium carbonate.
- Burning method
Burning method is to use magnesium ore to decompose to generate magnesium oxide at high temperatures, and then dissolve magnesium oxide in water, and to pass the method of carbon dioxide gas to generate magnesium carbonate. The purity of magnesium carbonate generated by this method is higher, but the process is complicated and the cost is high.
The specific process process of the burning method is as follows:
Broken and grind the magnesium ore;
Burn the magnesium ore at high temperature to generate magnesium oxide;
Moisturize magnesium oxide in water to obtain magnesium hydroxide solution;
Tong the carbon dioxide gas to make magnesium hydroxide solution carbon and generate magnesium carbonate to precipitate;
Separate magnesium carbonate sedimentation and dry it to get food -grade magnesium carbonate.
Food -grade magnesium carbonate should meet the following quality standards:
Appearance: white or slightly yellow powder, no clump;
Content: ≥99.0%;
Heavy metal: ≤10mg/kg;
Arsenic: ≤2mg/kg;
Lead: ≤2mg/kg;
Mercury: ≤0.5mg/kg;
Volatile substance: ≤1.0%;
Water: ≤1.0%.
Food -grade magnesium carbonate can be used in the food, medicine, cosmetics and other industries.
In the food industry, food -grade magnesium carbonate can be used as flour improvement agents, puff agents, antidents, nutritional enhancers, etc.
In the pharmaceutical industry, magnesium carbonate can be used as gastric acid neutral agents, laxatives, magnesium supplements, etc.
In the cosmetics industry, food -grade magnesium carbonate can be used as skin care products, fillers, adsorption agents, etc.