Nitric Acid 68%

Nitric Acid is a highly reactive and powerful acid, essential across a wide range of industries. Known for its oxidising properties, it is a key ingredient in manufacturing and industrial applications, offering unparalleled efficiency in complex chemical reactions. Whether you’re involved in the production of fertilisers, or metal treatments, our high-purity nitric acid ensures top-level performance and reliability, enabling precision and safety in every process.

Top 5 Common Uses for Nitric Acid:

1. Fertiliser Manufacturing: Used to produce ammonium nitrate, a key ingredient in nitrogen-based fertilisers.
2. Polymer Production: Essential in the creation of nylon and other synthetic fibre.
3. Metal Etching & Processing: Used for cleaning and etching metals, particularly in the electronics and aerospace industries.
4. Chemical Synthesis: Vital for producing various organic and inorganic compounds, including dyes and plastics.
5. Water Treatment: Helps in neutralising water contaminants and pH adjustment in wastewater treatment plants.

Nitric acid’s versatility and reliability make it indispensable for industries requiring precise chemical processes. When you need a solution you can trust for consistent results, choose our high-quality nitric acid.

Technical Reference

Technical Specifications

Applications & Use Cases

• Metal Passivation and Pickling: Passivation of stainless steel (typically used in blends with phosphoric or hydrofluoric acid); removal of scale, oxides, and heat tint from steel and aluminium surfaces in fabrication workshops.
• Electronics and Printed Circuit Board (PCB) Manufacture: Etching and cleaning of copper, nickel, and other conductive metals during PCB fabrication and microelectronics production.
• Gold and Precious Metal Refining: Used in aqua regia formulations (3:1 HCl:HNO₃ v/v) for dissolution and refining of gold, platinum group metals, and other noble metals in Australian assay and refining operations.
• Nitration Reactions: Production of nitroaromatic compounds, including intermediates for dyes, pharmaceuticals, and speciality chemicals.
• Analytical and Laboratory Chemistry: Sample digestion and acid dissolution of inorganic matrices for ICP-MS, ICP-OES, and AAS analysis; preparation of standard solutions and reagents.
• Water Treatment — pH Correction: Controlled acidification of cooling tower water, process water, and irrigation water (fertigation) to manage pH and improve nutrient availability in hydroponic and agricultural systems.
• Polymer and Synthetic Fibre Production: Nitration of aromatic compounds in the manufacture of nylon intermediates (e.g., adipic acid pathway), polyurethanes, and other synthetic polymers.
• Surface Preparation and Cleaning: Cleaning of dairy and food processing equipment (combined CIP formulations), stainless steel vessels, and heat exchangers to remove mineral scale and biofilm residues.
• Semiconductor Manufacturing: Cleaning and etching silicon wafers and semiconductor substrates as part of wet chemical processing sequences.
• pH Reduction in Hydroponics and Fertigation: Dilute nitric acid solutions are used to lower irrigation water pH (target 5.5–6.5) while simultaneously supplying nitrogen nutrition in closed and open hydroponic systems.

Dosing Rates & Guidelines

Important: All dosing rates listed are indicative only and based on standard Australian industry practice. Actual dose requirements will vary depending on water chemistry, substrate condition, temperature, system volume, and target outcome. Conduct jar testing or pilot-scale trials before full-scale application. Consult a qualified process chemist where required.

Dilution Instructions

General Principles

• Always add acid to water — never add water to concentrated acid. Adding water to concentrated nitric acid causes violent exothermic reactions, spattering, and the release of nitrogen dioxide (NO₂) fumes. This is a critical safety rule with no exceptions.
• Use only acid-resistant equipment: polyethylene (HDPE or LDPE), polypropylene (PP), or PVDF containers and transfer equipment. Do not use stainless steel, galvanised steel, copper, or mild steel vessels.
• Always work in a well-ventilated area, outdoors, or under local exhaust ventilation. Nitric acid fumes are acutely toxic.
• Have a running water supply immediately accessible for emergency dilution and first aid.

Step-by-Step Dilution Procedure

• Step 1 — Don PPE: Before handling, put on chemical-resistant gloves (neoprene or nitrile, minimum 0.3 mm thick), chemical splash goggles (not safety glasses), PVC or chemical-resistant apron, and chemical-resistant footwear. If working with large volumes or in enclosed spaces, wear a full-face respirator fitted with combination acid gas / P2 particulate cartridges (AS/NZS 1716 compliant).
• Step 2 — Prepare receiving vessel: Fill the HDPE or PP vessel with the required volume of clean, cold water first. Cold water reduces the heat of dilution. For large-volume dilutions (>10 L final volume), pre-fill with at least 75% of the total final water volume before any acid addition.
• Step 3 — Calculate volumes: Determine the volume of 68% acid required to achieve the target concentration. Example: to prepare 100 L of a 10% v/v working solution, add approximately 14.7 L of 68% acid (adjusting for density; 10% v/v of 68% acid in 100 L final volume). Always verify calculations independently before proceeding.
• Step 4 — Slow acid addition: Slowly pour or pump the concentrated 68% nitric acid into the water with continuous stirring. Add in small increments. Never pour rapidly. Maintain awareness of temperature — if the solution becomes hot to the touch through the vessel wall, pause addition and allow to cool before continuing.
• Step 5 — Mix thoroughly: Use a chemically resistant stirrer (HDPE or PTFE paddle). Ensure homogeneous mixing before sampling or use.
• Step 6 — Label immediately: Label the working solution container with chemical name, concentration, date of preparation, preparer name, and hazard information in accordance with the GHS/SDS labelling requirements under the WHS Regulations.
• Step 7 — Dispose of packaging safely: Rinse empty acid containers three times with water (adding rinsate to the dilution vessel if appropriate) before disposal. Follow local council and state EPA requirements for chemical waste disposal.

Chemical Compatibility

Compatible Materials (for storage and handling equipment)

• High-density polyethylene (HDPE) — preferred for storage and transfer
• Polypropylene (PP)
• Polyvinylidene fluoride (PVDF / Kynar)
• Polytetrafluoroethylene (PTFE / Teflon) — for fittings, gaskets, and seals
• Borosilicate glass (laboratory use; not suitable for large-volume industrial storage)
• Certain grades of high-alloy austenitic stainless steel (e.g., 304, 316) in dilute concentrations only and with caution — verify with corrosion data tables before use

Incompatible Materials — Do NOT Use

• Mild steel and carbon steel — rapid corrosion and hydrogen gas generation
• Galvanised steel — rapid attack
• Copper and copper alloys (brass, bronze) — vigorous dissolution and NO₂ gas evolution
• Aluminium — reacts under certain concentration and temperature conditions
• Natural rubber and most elastomers — rapid degradation
• Zinc and zinc alloys — vigorous reaction

Incompatible Chemicals — Do NOT Mix

• Organic materials and solvents (acetone, alcohols, ethers, hydrocarbons): Nitric acid is a powerful oxidising agent. Contact with organic compounds can cause violent reactions, ignition, or explosion. Never mix with any organic solvent.
• Concentrated sulphuric acid: Can generate nitronium ions; extremely reactive mixed acid with severe exotherm and explosion risk if in contact with organics.
• Acetic acid or acetic anhydride: Formation of acetyl nitrate — potential explosive.
• Ammonia and ammonium compounds: Exothermic reaction;