Hebei Messi Biology Co., Ltd. states that in industries such as mining, ports, building materials, and logistics, rubber conveyor belts are essential equipment for continuous transport. Key to ensuring the durability, heat resistance, flame retardancy, and stable operation of these conveyor belts is a functional inorganic material—magnesium oxide. Through its multiple roles in vulcanization activation, acid absorption stabilization, heat-resistant reinforcement, and flame retardancy and smoke suppression, it serves as an important additive in high-end conveyor belt formulations. Operating as a multifunctional inorganic additive, magnesium oxide supports the safety and efficiency of industrial conveyor belts, acting as an essential material behind modern logistics equipment.
The primary value of magnesium oxide in conveyor belts lies in its role as a key component of the vulcanization system. Specialty rubber compounds such as chloroprene rubber (CR), chlorinated polyethylene (CPE), and chlorosulfonated polyethylene (CSM) are the primary materials for high-temperature and oil-resistant conveyor belts, which release acidic byproducts like hydrogen chloride during vulcanization. Being weakly alkaline, magnesium oxide can rapidly neutralize these acidic substances to prevent compound scorching, cross-linking failure, and equipment corrosion. Meanwhile, it works synergistically with vulcanizing agents and accelerators to increase cross-linking density and vulcanization efficiency, transforming soft, sticky raw rubber into a tough elastomer. Data show that with the addition of appropriate magnesium oxide, vulcanization time can be reduced by 10% to 30%, while tensile strength and elasticity are noticeably improved.
Secondly, magnesium oxide acts as a heat-resistant and anti-aging stabilizer. Conveyor belts are subjected to prolonged friction, heavy loads, and high-temperature materials, making the rubber susceptible to thermal-oxidative aging and cracking. Magnesium oxide particles form a heat-resistant barrier within the compound, blocking free radical attacks on the molecular chains. This increases the strength retention rate after aging at 150°C from 60% to over 80%, nearly doubling the service life. In high-temperature conveying scenarios such as metallurgy and coking, this property directly determines whether the equipment can operate stably.
In environments with strict safety requirements, such as coal mines, underground facilities, and chemical plants, the flame-retardant and smoke-suppression functions of magnesium oxide are vital. When heated, it decomposes endothermically, releasing water vapor to dilute flammable gases. The resulting dense layer of magnesium oxide acts as a barrier to flame propagation. Additionally, it is halogen-free, low in toxicity, and provides effective smoke suppression, aligning with eco-friendly halogen-free flame retardancy regulations. This helps PVC solid-woven flame-retardant belts and rubber flame-retardant belts meet mining safety standards. Magnesium oxide also serves reinforcing and filling roles. High-activity, light magnesium oxide has a large specific surface area, offering good compatibility and uniform dispersion in rubber. It can enhance hardness, wear resistance, and dimensional stability while managing costs without significantly increasing the specific gravity of the belt, balancing performance and economic efficiency.
Magnesium oxide for conveyor belts is not a generic industrial-grade product but a specialized, customized material. The industry generally prefers high-activity grades with a purity of ≥95%, an iodine absorption value of ≥80 mg/g, a particle size of 3–10 μm, good dispersibility, and no agglomeration. The typical dosage is 2% to 5% of the rubber compound’s mass, adjusted according to the rubber type and performance targets. Using low-purity or low-activity magnesium oxide can easily lead to uneven dispersion, under-vulcanization, and decreased heat resistance, directly affecting the lifespan and safety of the conveyor belt.
From raw materials to finished products, specialized magnesium oxide is involved throughout the compounding, vulcanizing, and molding processes, contributing to the strength, heat resistance, flame retardancy, and weather resistance of the conveyor belt. As high-end development, green initiatives, and extended lifespans become key industry trends, high-activity, nano-modified, and low-impurity specialized magnesium oxide will continue to provide reliable support for intelligent logistics and green industrial conveying.