Basic Chromium Sulphate

Brief Overview
Basic chromium sulfate is an inorganic compound with the chemical formula Cr(OH)(SO₄). It is a green, odorless solid at room temperature. It is typically sold in powder form. Basic chromium sulfate has high tanning power and hence largely used in the tanning of leather. It is easily soluble in cold water and very soluble in hot water. Chromium, particularly in the hexavalent oxidation state, is toxic, hence basic chromium sulfate, which is comparatively less toxic, is preferred in the leather industry.

Manufacturing Process
Basic chromium sulphate is produced from the simple reduction of Cr (VI) to Cr (III) by the addition of an excess of sulphur dioxide. The reaction can be represented as:

Cr₂O3 + 3 H₂SO₄ → Cr₂(SO₄)₃ + 3 H₂O

Another reaction, based on the same mechanism as above, for the production of basic chromium sulphate industrially is:

Na₂Cr₂O₇ + 3SO₂ + H₂O → 2Cr(SO₄)(OH) + Na₂SO₄

The reaction is carried out in a steam-heated vessel. The excess sulphur dioxide formed during the reaction is removed in another reaction tower. The product obtained is in liquid state, it is spray dried to form a powder, which is later packed in bags and sold.

Brief Overview
Basic chromium sulfate is an inorganic compound with the chemical formula Cr(OH)(SO₄). It is a green, odorless solid at room temperature. It is typically sold in powder form. Basic chromium sulfate has high tanning power and hence largely used in the tanning of leather. It is easily soluble in cold water and very soluble in hot water. Chromium, particularly in the hexavalent oxidation state, is toxic, hence basic chromium sulfate, which is comparatively less toxic, is preferred in the leather industry.

Manufacturing Process
Basic chromium sulphate is produced from the simple reduction of Cr (VI) to Cr (III) by the addition of an excess of sulphur dioxide. The reaction can be represented as:

Cr₂O3 + 3 H₂SO₄ → Cr₂(SO₄)₃ + 3 H₂O

Another reaction, based on the same mechanism as above, for the production of basic chromium sulphate industrially is:

Na₂Cr₂O₇ + 3SO₂ + H₂O → 2Cr(SO₄)(OH) + Na₂SO₄

The reaction is carried out in a steam-heated vessel. The excess sulphur dioxide formed during the reaction is removed in another reaction tower. The product obtained is in liquid state, it is spray dried to form a powder, which is later packed in bags and sold.