Feed-Grade Bentonite Quality Requirements and Modification Processing Technology

Bentonite is rich in over 40 elements required for animal growth and development—such as calcium, iron, zinc, selenium, copper, magnesium, aluminum, silicon, sodium, sulfur, and chlorine. It not only supplements essential minerals but also activates enzymes in the body. Moreover, the elements in bentonite can help offset nutritional deficiencies caused by regional differences in feed ingredients. As a result, feed-grade bentonite plays a valuable role as a key component in complex premixed feed, mineral premixes, and compound additive products in China’s animal husbandry.

Bentonite exhibits excellent dispersibility and lubricity. When thoroughly stirred with feed additives, it ensures an even mix that can slow the passage of feed through the digestive tract. Its strong adsorption and expansion properties enhance nutrient absorption in the digestive system and effectively adsorb harmful substances—such as heavy metals (e.g., lead), bacterial toxins, and toxic gases. This, in turn, significantly improves the animal’s disease resistance, appetite, and digestive functions. Moreover, serving as a carrier for various enzyme additives, bentonite not only supplies essential minerals for growth and development but also has detoxification and immune-enhancing effects, making it a cost-effective and easily sourced natural mineral carrier.

1. Quality Requirements for Feed-Grade Bentonite
A review of extensive domestic and international literature shows that the levels of toxic and harmful substances in bentonite are very low, fully meeting the "Feed Hygiene Standards" (GB13078-2017) limits: Lead ≤15 mg/kg, Total Arsenic ≤10 mg/kg, Mercury ≤0.1 mg/kg, Cadmium ≤2 mg/kg, and Fluoride ≤400 mg/kg. These substances, once adsorbed by bentonite in the digestive tract, are excreted with feces, ensuring no toxic side effects. Therefore, using purified bentonite as a feed additive and diluent is safe for production animals. However, if the concentration of toxic substances exceeds a certain threshold, it may harm animal health, pollute the environment, and even damage production equipment due to the presence of metal fragments. Hence, it is necessary to establish quality standards for feed-grade bentonite—setting limits on additive dosages and specifying the content of key components such as montmorillonite (assessed by methylene blue adsorption), moisture and volatile substances, expansion index or water absorption, magnetic metal debris, particle passage rate, wet compressive strength, pH value, as well as the hygiene indicators outlined in the "Feed Hygiene Standards" (GB13078-2017). These standards can be tailored based on industry and company-specific requirements.

2. Modification Technology for Feed-Grade Bentonite
By using inorganic materials as carriers and incorporating antibacterial metal ions, inorganic antibacterial agents with a broad antibacterial spectrum, low potential for resistance, and long-term safety can be produced. The main components of feed-grade bentonite can serve as carriers for various inorganic antibacterial agents. For example, by loading antibacterial copper ions through physical adsorption and chemical ion-exchange reactions, a copper-loaded purified bentonite product is obtained. After copper ion loading, the bentonite surface retains a significant positive charge, thereby effectively enhancing its ability to adsorb negatively charged pathogenic bacteria. The gradual release of the antibacterial copper ions further bolsters both the adsorption and bactericidal properties of the bentonite. While bentonite is inherently hydrophilic—resulting in relatively weak adsorption for organic compounds—modifying natural bentonite with organic agents enables these modifiers to more effectively penetrate the interlayer structure. This rapid chelation alters both its surface properties and crystal structure, significantly enhancing its overall adsorption performance.

Note: The content in this article is sourced from the internet. Data may be delayed. It is shared for informational purposes only. Please notify for removal if any infringement is found!