NaOH 50% -- Technical Specifications, Applications & Price List (CAS 1310-73-2)

NaOH 50% (CAS 1310-73-2) is a commercial concentrated sodium hydroxide solution, specific gravity 1.52 g/mL, NaOH content 50% nominal (actual value per batch COA). 6 industry applications: wastewater treatment, paper production, textile dyeing, soap manufacturing, food processing, oil & gas. Loc Thien supplies by tanker truck 5–30 tons, IBC 1000L, COA per batch — Tax ID 0313650856 — Hotline 0979 891 929.

What Is NaOH 50%? — COA Parameters and Basic Properties

NaOH 50% (sodium hydroxide 50%, liquid caustic soda 50%) is a strong alkali solution produced by ion-exchange membrane electrolysis technology. Below are typical COA parameters from Hoa Chat Loc Thien.

Typical COA — NaOH 50%

NaOH 50% vs. 32% vs. 45%

All three concentrations are liquid NaOH solutions. The key differences lie in active ingredient content and freezing point.

NaOH 50% offers the lowest transport cost per kg of active ingredient — approximately 36% less solution mass (~43% less volume) than 32%. The freezing point of +12°C requires heat tracing and insulation during winter.

6 Main Industrial Applications

Wastewater Treatment — pH Neutralization and Heavy Metal Precipitation

NaOH 50% is used to neutralize acidic waste streams (pH < 6) to 6.5–8.5 before discharge. Reference dosage: 0.1–0.5 kg NaOH 50%/m³ of wastewater depending on influent acid load.

For heavy metal treatment, NaOH 50% precipitates metal ions as hydroxides: Cu²⁺ + 2OH⁻ → Cu(OH)₂↓; Zn²⁺ + 2OH⁻ → Zn(OH)₂↓; Cr³⁺ + 3OH⁻ → Cr(OH)₃↓. Removal efficiency exceeds 99% when maintaining pH 8.5–9.5.

Paper Production (Kraft Pulping) — Lignin Removal, Pulp Bleaching

In the Kraft process, NaOH 50% together with Na₂S forms white liquor to break lignin-cellulose bonds. Typical consumption: 150–200 kg NaOH 100%/ton of pulp. NaOH 50% is preferred because higher concentration reduces water volume entering the digester, increasing digester productivity.

Textile Dyeing — Mercerizing, Bleaching, pH Adjustment

NaOH 50% is used in the mercerizing process — treating cotton fabric with concentrated alkali (20–28°Be) to increase luster, color fastness, and dye uptake. Dosage: 30–80 kg NaOH/ton fabric depending on mercerizing machine type. Requires high-purity NaOH with low NaCl and Na₂CO₃. A low NaCl level, as stated on the batch COA, helps avoid undesirable white spots on fabric surfaces.

Soap and Detergent Production — Saponification

Reaction: triglyceride + NaOH → glycerol + fatty acid salt (soap). Dosage: 130–140 kg NaOH 100%/ton of oil/fat depending on SAP value (≈ 260–280 kg NaOH 50%). NaOH 50% is preferred in industrial soap production due to its smaller volume compared to 32%, reducing delivery frequency and storage tank capacity.

Food Processing — Fruit Peeling, CIP, Sugar Production

In CIP (Clean-in-Place) processes, NaOH 50% is diluted to 0.5–2%, circulated at 60–80°C for 10–30 minutes to clean tanks and pipes. AISI 304/316 stainless steel is fully compatible at this concentration. Other applications: fruit peeling (soaking in 1–3% NaOH), ion exchange resin regeneration in sugar production.

Oil & Gas Industry — Acid Neutralization, Sulfur Purification

NaOH 50% neutralizes H₂S and acidic compounds in natural gas and crude oil. The Claus sulfur treatment process requires NaOH to absorb and neutralize residual H₂S.

Dilution and Dosage Calculation Guide

Basic formula: m₁ × C₁ = m₂ × C₂, where m₁ = mass of NaOH 50% needed (kg), C₁ = NaOH 50% concentration (50%), m₂ = mass of solution to prepare (kg), C₂ = desired concentration (%).

Example: CIP process needs 500 kg of 5% NaOH solution → m₁ = 500 × 5 ÷ 50 = 50 kg NaOH 50%.

Safe dilution: Always add NaOH slowly to water (never reverse). Diluting NaOH 50% generates significant heat — requires continuous stirring and slow addition to prevent overheating (thermal shock can crack plastic tanks).

Operating Considerations

Freezing Point +12°C — Risks and Solutions

NaOH 50% begins to crystallize at approximately +12°C — clearly higher than 32% (about +5°C; a 31–33% batch can start anywhere from about 2 to 8°C) and 45% (about +6–7°C). Crystals may not appear right away even below the crystallization point, and outdoor pipes, valves and pump heads crystallize first. Reference figures follow the NaOH–H₂O phase diagram and technical literature from caustic soda producers; the actual crystallization point depends on each batch’s concentration per its COA/TDS. In northern Vietnam, winter temperatures can drop below 10°C. Solution: heat tracing with heating tape or steam, insulation of storage tanks and piping with fiberglass or polyurethane. When NaOH 50% has solidified, never heat directly with flame or immersion heaters — use indirect heating with steam jacket or hot water.

Compatible Storage Tank Materials

Case Study — Cost Savings from Switching from NaOH 32% to 50%

A paper mill at Nhon Trach Industrial Park consuming 80 tons NaOH 100%/month had used NaOH 32% for 10 years. The mill switched to NaOH 50% to reduce logistics costs and free up warehouse space.

Actual data:

Results after 6 months: Transport cost reduced 36%/month, tank reduced from 50m³ to 30m³ freeing 20m³ for other chemicals, reduced 1 staff for receiving and pumping, no change in pulp quality.

ROI and Payback Period

Investment: new tank + heat tracing + valve and pump modifications — equivalent to roughly 4 months of logistics savings (36% lower per month), so the payback period is ~4 months.

Latest 2026 Pricing

Why there is no fixed price list

NaOH 50% is supplied in bulk lots to factories, industrial parks and wastewater plants. The actual unit price depends on volume, delivery region, packaging and contract terms, and source prices and exchange rates also change over time. A single published number would not reflect your real cost — so Loc Thien issues a written quotation for each request, with a stated validity period.

5 factors that determine the NaOH 50% unit price

What a Loc Thien NaOH 50% quotation includes

• Unit price per kg or per ton of solution, with the concentration stated
• Price with or without VAT — full VAT invoice (Tax ID 0313650856)
• Freight to your plant, or ex-warehouse price
• Payment terms and quotation validity
• Estimated delivery: HCMC inner city 4 hours; Southern and Mekong industrial parks 24–48 hours; North and Central 2–3 days
• Batch COA and MSDS

Real Cost Comparison Between Suppliers

Comparing price per kg of solution is not enough — convert to cost per kg of NaOH 100%.

Formula: Cost/kg NaOH 100% = Price/kg solution ÷ Concentration (as a decimal)

Example: you receive quotes of P₃₂ for 32% caustic and P₅₀ for 50% caustic (VND/kg solution). Compare P₃₂ ÷ 0.32 with P₅₀ ÷ 0.50 — 50% is cheaper per kg of active NaOH whenever P₅₀ < 1.5625 × P₃₂. Freight is charged on solution weight, which tips the balance further toward 50% (about 36% less mass to haul).

Get a quote within 15 minutes: send concentration, volume, delivery location, packaging and COA requirements via 0979 891 929, [email protected] or the quote request form.

Frequently Asked Questions

Does NaOH 50% corrode stainless steel?

NaOH 50% does not corrode AISI 304/316 stainless steel at temperatures below 80°C. This material is recommended for storage tanks. Do not use aluminum, zinc, copper, or galvanized tanks.

At what temperature does NaOH 50% solidify?

NaOH 50% begins solidifying at approximately +12°C. Below 12°C, NaOH·nH₂O crystals form, clogging valves and pipes. Heat tracing and insulation are required in winter.

Where can I buy large quantities of NaOH 50%?

Hoa Chat Loc Thien supplies NaOH 50% in 5–30 ton tank trucks and 1000L IBCs nationwide — 6 warehouses, a fleet of tank trucks. Delivery within 4 hours in inner HCMC. Hotline 0979 891 929.

What is the difference between NaOH 50% and NaOH 32%?

NaOH 50% has higher specific gravity (1.52 vs 1.348), higher freezing point (about +12°C vs about +5°C), but transport cost per kg NaOH 100% is ~36% lower. NaOH 50% suits large-scale plants with heat tracing; NaOH 32% suits small plants in hot climates.

How to check NaOH 50% quality at the warehouse?

Measure specific gravity with hydrometer at 20°C — NaOH 50% has SG 1.52 g/mL. Titrate with 1N HCl using phenolphthalein indicator for precise NaOH content determination.

Is a special permit needed to transport NaOH 50%?

NaOH 50% is classified as UN 1824, Class 8 — tank trucks must be registered for dangerous goods. Loc Thien has a fleet of dedicated tank trucks with full dangerous goods registration and certified drivers.