Aluminum Sulfate Al₂(SO₄)₃ - Water Treatment Coagulant, Paper Sizing Agent, and

Product Specification

Product Title

Aluminum Sulfate Al₂(SO₄)₃ - Water Treatment Coagulant, Paper Sizing Agent, Soil pH Adjuster

English Description

Aluminum sulfate, with the chemical formula Al₂(SO₄)₃, commonly exists in hydrated forms (e.g., octadecahydrate). This product is a white or slightly grayish crystalline, flake, or lump solid. As one of the oldest and most widely used inorganic coagulants, aluminum sulfate continues to play a fundamental and crucial role in both traditional and modern industries—including water treatment, papermaking, firefighting, chemicals, and soil amendment—relying on its reliable capabilities in charge neutralization, adsorption bridging, and sweep coagulation.

In-Depth Analysis of Core Applications:

1. The Classic Cornerstone of Water Treatment: Aluminum sulfate is the most commonly used coagulant in waterworks and wastewater treatment plants. Upon addition to water, it rapidly hydrolyzes, generating positively charged aluminum hydroxide colloids. These efficiently adsorb and agglomerate negatively charged suspended particles, colloidal impurities, some dissolved organic matter, and microorganisms, forming large, settleable or filterable flocs. This significantly reduces water turbidity, color, and COD. With stable performance suitable for various raw water conditions, and some effectiveness even with cold, low-turbidity water, it remains a classic choice for ensuring safe drinking water and compliant wastewater discharge.

2. The Traditional Fixative in Paper Industry: In papermaking processes, aluminum sulfate (alum) was long employed as the fixative for acidic sizing. It promotes the precipitation and fixation of rosin size onto fibers, enhancing the paper's water resistance (sizing degree). Although its usage has declined with the widespread adoption of neutral/alkaline papermaking systems, it still finds important applications in the production of certain specialty papers (e.g., banknote paper, archival paper) and in acidic system papermaking. Concurrently, it is a common coagulant for treating paper mill effluent.

3. The Multi-Functional Assistant in Soil Management and Firefighting:

   • Soil pH Adjuster: The hydrolysis of aluminum sulfate produces acidity, making it useful for amending alkaline soils by lowering soil pH, thereby creating a suitable growing environment for acid-loving plants (e.g., azaleas, camellias, blueberries).

   • Raw Material for Firefighting Foam: It is an important chemical raw material for producing protein-based and some synthetic firefighting foams.

   • Other Uses: Applications also include fat and oil clarification (as a decolorizing/purifying agent), catalyst support manufacturing, pigment precipitation, and tanning.

4. Specific Roles in Modern Applications: Although partially replaced by more efficient products like Polyaluminum Chloride (PAC) in some areas, aluminum sulfate maintains an irreplaceable position due to its extremely low cost, simple production process, and no risk of residual toxicity. This is evident in budget-sensitive water treatment projects, processes with specific requirements for aluminum species, and as a raw material for producing other aluminum salts (e.g., PAC, potassium alum).

This product is graded based on Al₂O₃ content (e.g., Industrial Grade, Water Treatment Grade). Our supplied aluminum sulfate features good solubility, low impurity content, and stable coagulation performance. It is available in lump, flake, and powder forms to facilitate storage, transportation, and dosing under different conditions. We provide reliable, highly cost-competitive products to waterworks, paper mills, soil amendment companies, and chemical plants. We also offer technical consultation based on customer needs to help achieve optimal application results and cost control.