The terms 'activated alumina' and 'gamma alumina' are often used interchangeably, but understanding their nuances is key to selecting the right material for specific industrial needs. Both are forms of aluminum oxide (Al2O3), but their preparation and resulting properties lead to distinct applications. NINGBO INNO PHARMCHEM CO.,LTD. clarifies these differences and their impact on performance.

Activated alumina is a general term referring to highly porous aluminum oxide that has been processed to maximize its surface area, making it an excellent adsorbent. It is typically produced by dehydrating aluminum hydroxide at controlled temperatures. The specific crystalline phase formed during this process significantly influences its properties.

Gamma alumina (γ-Al2O3) is one of the most common phases of activated alumina. It is formed when aluminum hydroxide is calcined at temperatures typically between 400°C and 800°C. This process results in a highly porous structure with a large specific surface area (often exceeding 200 m²/g) and a disordered, metastable crystalline form. These characteristics make gamma alumina exceptionally good at adsorption, making it ideal for applications such as drying, purification, and as a catalyst carrier.

In contrast, alpha alumina (α-Al2O3) is the thermodynamically stable form of aluminum oxide, typically formed at much higher calcination temperatures (above 1000°C). Alpha alumina has a denser, less porous structure and is known for its exceptional hardness, strength, and wear resistance. Due to these properties, alpha alumina is primarily used in applications like abrasives, cutting tools, ceramics, and refractory materials, rather than as an adsorbent or catalyst support.

Therefore, when discussing materials for adsorption, drying, or catalysis, 'gamma alumina' is often a more precise descriptor of the *type* of activated alumina being used. The high surface area and pore volume of gamma alumina are critical for its function as a desiccant, gas adsorbent, and support for catalytic materials. For instance, in water defluorination or the drying of industrial gases, the specific properties of gamma alumina are leveraged.

While 'activated alumina' is the broader category, 'gamma alumina' refers to a specific, highly functional phase within that category, particularly valued for its adsorptive and catalytic support capabilities. NINGBO INNO PHARMCHEM CO.,LTD. supplies high-quality gamma alumina powder, recognizing its critical role in a wide array of advanced industrial applications.