Basic Chromium Sulfate CAS 39380-78-4

What Basic Chromium Sulfate Does

Basic chromium sulfate is the standard chrome tanning agent tanneries use to turn pickled hide into wet-blue leather. It arrives pre-basified, meaning the chromium complexes are already formed under factory control, so the tannery avoids the batch-to-batch variation of basifying raw chromium sulfate by hand in the drum. Tanned leather reaches a shrink temperature above 95 °C, stable enough for footwear, garment and upholstery work. The product is sold as dark green liquid or light green spray-dried powder.

Choosing the Right Basicity

Basicity is the one number to choose first. Low-basicity grades (25-30%) form smaller complexes that travel deeper into thick, heavy hides, so they suit sole and harness leather. The 33% grade is the industry workhorse for footwear uppers, garments and general wet-blue. High-basicity grades (38-42%) fix faster with tighter grain and shorter drum cycles, which suits thin upholstery and garment skins.

Main Tanning and Other Uses

• Main chrome tanning. Dosed straight into the drum with pickled cowhide, sheepskin, goatskin or pigskin; no separate dissolution or stepwise basification needed.
• Retanning. Builds chromium content, refines grain and evens out dye and fatliquor distribution; blends with vegetable and synthetic tannins for firmness and feel.
• Industrial uses. Mordant for acid dyes on wool and nylon; trivalent chromium passivation on steel and zinc; feedstock for catalysts and ceramic green pigments.

33% Basicity Liquid Grade Specifications

Packaging, Storage and Ordering

• Liquid: keep in sealed HDPE or corrosion-resistant containers at 5-35 °C and do not let it freeze; keep away from strong alkalis. Powder: keep sealed and dry so it does not cake.
• Both forms are corrosive to skin, eyes and airways. Wear gloves, face shield and protective clothing when charging drums. Classified as corrosive goods for transport, with full labeling and documents.
• Packaging: 25 kg bags (powder), 200 kg HDPE drums and 1000 kg IBC totes (liquid); COA, TDS and SDS with every order; samples available; quotes within one working day. Related tannery chemicals: Sodium Formate CAS 141-53-7 and Chrome-free Zeolite Tanning Agent CAS 68989-22-0.

FAQ

Q: What makes BCS better than basifying raw chromium sulfate on site?

A: Pre-basified for consistent batches; hand basifying risks pH drift and uneven tannage.

Q: How do I pick the right basicity grade?

A: 25-30% for thick hides, 33% general purpose, 38-42% for thin skins and fast cycles.

Q: What shrink temperature can I expect from standard BCS tannage?

A: Around 95-105 °C at standard dosage, enough for most footwear and upholstery grades.