Active Zinc Oxide or Zinc Oxide Active is a specialized chemical which is used to accelerate the
vulcanization of rubber. These are very small particles and transparent in appearance but are one of
the most important activators. These chemicals scale low in impurity levels but contributes more as
an activator even with less dosage. It helps in increasing the quality of rubber and also improves the
Advantages of Active Zinc Oxide:
1. It has a much lower content of heavy metals.
2. It is very suitable for transparent or translucent rubber products and those with a low zinc
3. The super-fine particles of the product will disperse easily in the rubber. The
dosage is smaller than ordinary (French process) zinc oxide powders.
4. A large dosage of the product can serve as the anti-softening agent, preventing rubber
materials from being transformed easily. It also can be used as the filler for light-colored
5. The tear resistance, tensile coefficient, and wear resistance of rubber products are all higher.
6. The range of vulcanization is larger, greatly reducing the danger of insufficient or excessive
7. Its content of heavy metals meets the strict standards of fodder additives, and the quality is
excellent (refer to the attached table).
8. Strict quality control allows the zinc oxide content of the finished product to reach the upper
limit in that activity level (higher than the products of the same level available on the
market), leading to the best condition of vulcanization, and offering the user the highest
economic efficiency and quality.
9. The features of active zinc oxide include smaller particle size than ordinary zinc oxide , lower
content of impurities, and larger relative surface area.
10. It can be applied as the rubber activators, EVA and mineral additive of feed.
For industrial use, ZnO is produced at levels of 105 tons per year by three main processes:
Indirect process: In the indirect or French process, metallic zinc is melted in a graphite crucible and vaporized at temperatures above 907 °C (typically around 1000 °C). Zinc vapor reacts with the oxygen in the air to give ZnO, accompanied by a drop in its temperature and bright luminescence. Zinc oxide particles are transported into a cooling duct and collected in a bag house. This indirect method was popularized by LeClaire (France) in 1844 and therefore is commonly known as the French process. Its product normally consists of agglomerated zinc oxide particles with an average size of 0.1 to a few micrometers. By weight, most of the world's zinc oxide is manufactured via French process.
Direct process: The direct or American process starts with diverse contaminated zinc composites, such as zinc ores or smelter by-products. The zinc precursors are reduced (carbothermal reduction) by heating with a source of carbon such as anthracite to produce zinc vapor, which is then oxidized as in the indirect process. Because of the lower purity of the source material, the final product is also of lower quality in the direct process as compared to the indirect one.
Wet chemical process: A small amount of industrial production involves wet chemical processes, which start with aqueous solutions of zinc salts, from which zinc carbonate or zinc hydroxide is precipitated. The solid precipitate is then calcined at temperatures around 800 °C.