Phosphoric Acid 30% - The Ultimate Rust Remover Solution

Product Overview

Phosphoric Acid 30% is a high-purity, clear orthophosphoric acid solution formulated for industrial metal treatment and rust removal. This reagent grade material (CAS 7664-38-2) maintains a strict assay of 29–31% w/w, ensuring consistent etching rates and pH control in manufacturing environments. With a density of 1.07 g/mL and low specific gravity variance (1.12–1.14), it is optimized for precise dosing in metering systems.

As a potent rust converter and scale remover, this 30% solution effectively prepares steel surfaces by converting iron oxide into a stable protective phosphate layer, significantly enhancing primer and coating adhesion. The manufacturing process ensures minimal impurity loads, with strict limits on chlorides, sulfates, and heavy metals, preventing contamination in sensitive downstream applications. Also known as Orthophosphoric Acid, this solution is water-soluble with a viscosity of 1.5 cP, allowing for excellent surface wetting on corroded substrates.

Key Properties

• Chemical Name: Phosphoric Acid 30% (Orthophosphoric Acid)
• CAS Number: 7664-38-2
• Grade: Reagent
• Appearance: Clear, colorless liquid
• Formula: H₃PO₄
• Specific Gravity (20°C): 1.12 – 1.14
• Chloride (Cl⁻): Max 50 ppm
• Sulfate (SO₄²⁻): Max 100 ppm
• Iron (Fe): Max 1 ppm
• Heavy Metals (as Pb): Max 0.5 ppm
• Solubility: Completely soluble in water

Common Applications

• Rust Removal & Metal Treatment: Primary agent for dissolving rust (iron oxide) and etching metal surfaces prior to painting or powder coating. Creates a phosphate conversion coating that improves corrosion resistance.
• pH Adjustment: Used in industrial water treatment facilities to lower pH levels and control alkalinity, stabilizing process water chemistry.
• Laboratory & Research: Utilized as a reagent in chemical analysis and formulation development due to its high purity and low heavy metal content.
• Industrial Cleaning: Effective ingredient in acid cleaners for removing mineral deposits, scale, and hard water buildup from industrial equipment.
• Fertilizer Manufacturing: Acts as a phosphorus source in the production of specialized liquid fertilizers for agricultural applications.

Safety & Handling

Classification: Corrosive (Class 8). Causes severe skin burns and eye damage. May be corrosive to metals.

Handle with appropriate Personal Protective Equipment (PPE), including chemical-resistant gloves, splash goggles, and face shields. Ensure adequate ventilation to avoid inhaling mists. Store in high-density polyethylene (HDPE) or glass containers, separated from strong alkalis and oxidizing agents. In case of spill, neutralize with soda ash or lime before disposal in accordance with local regulations.

Shipping Information: UN 1805, Phosphoric Acid Solution, Class 8, PG III.

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