Polyaluminum Chloride (PAC) is a highly effective inorganic polymer coagulant widely employed in water treatment processes worldwide. While its primary function is to aggregate suspended particles, its performance is significantly influenced by various chemical properties, with basicity being one of the most critical. Understanding PAC basicity is key for procurement managers and R&D scientists to select the optimal product for their applications. As a leading manufacturer and supplier, we aim to clarify this important aspect of PAC selection.

What is Polyaluminum Chloride Basicity?

Basicity in PAC refers to the molar ratio of hydroxyl groups (OH-) to aluminum ions (Al3+) within the polymer structure. It's often expressed as a percentage. For instance, a basicity of 45-55% indicates that for every three moles of hydroxyls, there are approximately 1.5 to 2.2 moles of them present relative to aluminum. This polymerization process is what gives PAC its superior coagulating abilities compared to simpler aluminum salts like aluminum sulfate.

The basicity of PAC directly impacts its performance in several ways:

• Polymerization Degree: Higher basicity generally signifies a higher degree of polymerization, meaning the aluminum ions are linked by hydroxyl bridges into larger, more complex polymeric structures.
• Charge Neutralization Efficiency: These larger polymers carry a higher positive charge density, allowing them to more effectively neutralize the negative charges on colloidal particles in water.
• Floc Formation: Higher basicity PACs tend to form larger, denser, and faster-settling flocs, leading to improved sedimentation and filtration efficiency.
• Dosage Requirements: Products with optimal basicity often require lower dosages to achieve the same level of water clarification, offering cost benefits.

The Relationship Between Basicity, Color, and Application

Generally, PAC products with higher basicity (e.g., above 70-80%) are often yellow or pale yellow, often produced through spray-drying processes that yield higher aluminum oxide content. These are typically used for industrial wastewater treatment where their robust performance is highly valued. On the other hand, white PAC products, often with basicity in the range of 45-55%, are usually produced with even greater purity and are preferred for drinking water treatment. This distinction allows users to choose PAC based on both performance needs and purity requirements.

Selecting the Right PAC: What to Look For

When you are looking to buy Polyaluminum Chloride, consider these factors related to basicity:

• Application Specifics: For drinking water, a lower basicity (white PAC) is often preferred for its higher purity. For industrial wastewater, higher basicity (yellow PAC) can offer superior performance and cost-effectiveness.
• Water Characteristics: The turbidity, pH, and temperature of the water to be treated will influence the optimal basicity and dosage.
• Supplier Expertise: Partner with a knowledgeable manufacturer and supplier that can provide technical data sheets and guidance on PAC basicity and its implications for your specific water treatment challenges.

As a leading supplier of Polyaluminum Chloride in China, we offer a range of PAC products with varying basicity levels to suit diverse needs. We encourage our clients to perform jar tests to identify the ideal basicity and dosage for their unique water sources. If you need to purchase PAC and want to ensure you are selecting the product with the most appropriate basicity for your application, please contact us. We are committed to providing high-quality chemicals and expert support to achieve optimal water treatment results.