The hardness of activated carbon is usually tested by the following methods:

The hardness of activated carbon is one of the key indicators for assessing its physical properties and service life, especially in application scenarios requiring repeated treatments, such as the water treatment and the gold recovery. High hardness activated carbon not only reduces calcification and breakage during transport and treatment, but also maintains its adsorption capacity and efficiency.

The hardness of activated carbon is affected by many factors:

• Raw materialsThe raw material of the activated carbon affects its hardness, for example, activated carbon made from coconut shell has a higher hardness than activated carbon made from other raw materials.
• Activation methodActivated carbon hardness is also affected by its activation method. Different activation methods result in activated carbon with different pore structures and surface properties, which affects its hardness.
• Pore size and distributionPore size and pore distribution also affect the hardness of the activated carbon. In general, the more developed the pore structure, the lower the hardness of the activated carbon.

The hardness of the activated carbon also affects its adsorption performance:

• Activated carbons with higher hardness tend to have greater structural stability, which helps to maintain their adsorption performance.
• Activated carbons with lower hardness may be more susceptible to fragmentation during the adsorption process, which affects their long-term performance.

Different applications require different hardnesses of activated carbon:

• Water treatmentIn water treatment, activated carbon needs to have a high hardness to resist scour and water flow pressure, reduce abrasion and fragmentation to maintain its adsorption performance and prolong its service life.
• Air purificationActivated carbon used for air purification, especially in industrial gas purification and automotive exhaust gas treatment systems, requires high hardness to withstand gas flow and possible physical impacts to ensure effective adsorption performance over the long term.
• Food and beverage industryIn the food and beverage industry, activated carbon is used for decolorization, refining and removal of impurities, and requires moderate hardness to ensure that product quality is not compromised by excessive fragmentation during processing.
• Mining industryIn the mining industry, especially for the extraction of precious metals such as gold, activated carbon is often required to have a high hardness to resist abrasion during ore processing and to ensure extraction efficiency.

Choosing the right hardness of activated carbon is critical to ensure its performance and longevity in a given application. Understanding the relationship between hardness and adsorption performance can help users select the right activated carbon product for their specific needs.