Sodium aluminate

Sodium aluminate

File:Unit cell of NaAlO2.png

Unit cell of NaAlO₂

Sodium aluminate is a chemical compound with the formula NaAlO₂. It is a white crystalline solid that is soluble in water and is used in various industrial and chemical applications. Sodium aluminate is primarily used in water treatment, as a source of alumina in the paper industry, and as an intermediate in the production of other chemicals.

Structure

Sodium aluminate is composed of sodium (Na), aluminum (Al), and oxygen (O) atoms. The compound forms a crystalline structure, as depicted in the unit cell image. The structure consists of a network of AlO₄ tetrahedra linked by shared oxygen atoms, with sodium ions balancing the charge.

Production

Sodium aluminate is typically produced by dissolving aluminum hydroxide in a sodium hydroxide solution. The reaction can be represented as follows:

Al(OH)₃ + NaOH _ NaAlO₂ + 2 H₂O

This process results in the formation of sodium aluminate and water. The product can be isolated by evaporating the water and allowing the sodium aluminate to crystallize.

Applications

Water Treatment

Sodium aluminate is widely used in water treatment processes. It acts as a coagulant, helping to remove impurities and suspended solids from water. The compound is effective in adjusting the pH of water and enhancing the removal of phosphates, which can contribute to eutrophication in water bodies.

Paper Industry

In the paper industry, sodium aluminate is used as a source of alumina. It is added to paper pulp to improve the paper's strength and opacity. The compound also aids in the retention of fillers and fine particles during the paper-making process.

Chemical Intermediate

Sodium aluminate serves as an intermediate in the production of various chemicals. It is used in the synthesis of zeolites, which are important in catalysis and ion-exchange applications. Additionally, sodium aluminate is involved in the production of alumina-based materials and ceramics.

Safety and Handling

Sodium aluminate should be handled with care, as it is a caustic substance. Protective equipment, such as gloves and goggles, should be worn to prevent skin and eye contact. In case of exposure, affected areas should be rinsed thoroughly with water.

Related pages

• Sodium hydroxide
• Aluminum hydroxide
• Zeolite
• Water treatment