What is the development potential of magnesium hydroxide, an additive-type inorganic flame retardant?

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Those familiar with flame retardants know that magnesium hydroxide is an inorganic flame retardant that is added to materials; compared to other inorganic flame retardants of the same type, it offers a better and more effective smoke suppression effect. It is understood that 80% of those who die in fires do so as a result of smoke asphyxiation; therefore, experts developing flame retardants must pay special attention to the fact that \"smoke suppression\" is far more important than \"flame retention\". This is because magnesium hydroxide begins to decompose when heated between 340°C and 490°C, thereby serving to absorb the heat from the surface of burning materials and prevent combustion. At the same time, it releases a large amount of moisture, thereby diluting the oxygen on the surface of the combustible material. The active magnesium oxide produced as a result adheres to the surface of the combustible material, further preventing the progress of combustion. Secondly, magnesium hydroxide does not produce any harmful substances throughout the flame-retardant process; moreover, the products resulting from its decomposition not only provide flame-retardant effects but also can absorb large amounts of the smoke and harmful gases generated by the combustion of plastics, rubbers, and other polymers. Active magnesium oxide can continuously absorb the unburned molten residues, thereby rapidly stopping the combustion, eliminating smoke, and preventing droplets from forming. It is an emerging environmentally friendly inorganic flame retardant. Based on their chemical composition, flame retardants can be divided into two main categories: organic flame retardants and inorganic flame retardants. Organic flame retardants are further divided into two categories: halogen-based and phosphorus-based. Due to drawbacks such as heavy smoke generation and high toxicity of decomposition products, organic flame retardants are gradually being replaced by inorganic flame retardants. Magnesium hydroxide does not emit any harmful substances during its production, use, and disposal, and it can also neutralize the acidic and corrosive gases generated during combustion; it is therefore an environmentally friendly green flame retardant. Magnesium hydroxide has a high thermal decomposition temperature, 140°C higher than that of aluminum hydroxide, which is currently used as an inorganic flame retardant. This allows synthetic materials containing magnesium hydroxide to withstand higher processing temperatures, thereby speeding up the extrusion process and reducing molding time. It also helps to improve the flame retardancy efficiency. Magnesium hydroxide has a fine particle size, which results in less wear on equipment and helps to extend the service life of processing equipment. Additionally, it is readily available as a raw material, leading to low production costs; it can therefore be widely used in fields such as polypropylene, polyethylene, polyvinyl chloride, high-impact polystyrene, and ABS. Currently, in foreign countries, there are over 20 companies in nearly 10** regions that produce more than 20 different types of products, with an overall annual production capacity of around 170,000 tons. Many new magnesium hydroxide plants are **currently under construction or planned for construction. According to relevant reports, the total annual production capacity of magnesium hydroxide plants to be built in recent years is approximately 140,000 tons. China’s current annual production capacity for magnesium hydroxide flame retardants is approximately 13,000 tons. Due to an increasing awareness of environmental protection, inorganic flame retardants are widely used abroad; in the United States, Japan, and Western Europe, the consumption of inorganic flame retardants accounts for 60%, 64%, and 50% of the total flame retardant consumption respectively. Among them, inorganic flame retardants are mainly aluminum hydroxide and magnesium hydroxide. Due to the many advantages of magnesium hydroxide over aluminum hydroxide, its proportion is increasing. According to foreign statistics, in Western developed countries, the consumption of magnesium hydroxide as a flame retardant accounts for over 30% of the total consumption of inorganic flame retardants. The current annual consumption in the United States, Western Europe, and Japan is approximately 50,000 tons, 80,000 tons, and 30,000 tons respectively. It is estimated that over the next 5 years, the average annual growth rates of consumption in the United States, Western Europe, and Japan will be 12%, 8%, and 7%, respectively. Based on the above analysis, the development prospects for magnesium hydroxide flame retardants worldwide are bright.