Specifications, Applications and Production of Sodium Aluminate

Hi Friends,

In present post, we will discuss the specifications, applications and production process route for Sodium aluminate as described in subsequent paragraphs. CAS number for Sodium aluminate product is 1302-42-7.

Specifications:

Sodium aluminate is marketed in liquid as well as solid powder forms as per specifications given below.

Specifications of Liquid Sodium Aluminate:-

Liquid Sodium aluminate is transparent viscous liquid having following compositions- 

Al2O3 : 24.5 to 26%,

Na2O : 20 to 21%,

Total solids: 45 to 46%.

Specifications of Solid Sodium aluminate:-

Solid sodium aluminate is a hygroscopic and powdery granular material readily soluble in water. Its aqueous solution on absorption of CO2 causes precipitation of aluminium hydroxide. 
Specifications of solid sodium aluminate are outlined below-

Al2O3 : 45 - 47%,

Na2O : 28 - 32%,

Fe2O3 : 0.005 %,

SiO2 : 0.010%,

Water insolubles: 0.50% max.

Main Applications:

• Water treatment,
• Preparation of water resistant concrete mixes,
• Production of synthetic zeolite,
• Manufacture of soap,
• Paper industries,
• Manufacture of titanium dioxide pigments.

Production process route:

Liquid sodium aluminate is generally produced by heating hydrated alumina with 48.5% caustic soda at about 105 degree centigrade.  The solution thus prepared is further boiled till formation of sodium aluminate pulp because of evaporation of water. The pulp is poured and cooled down  forming solid mass containing about 70% NaAlO2. This solid is crushed and dried producing the product with 90% NaAlO2, 1% moisture and 1% free NaOH. The capital investment for such project is very low but production cost is high because of higher input cost of hydrated alumina. For every tonne of 100% purity level sodium aluminate production, about one tonne of Hydrated alumina with physical moisture of 10% 0.50 tonne of NaOH are required. The plant also requires water evaporation of about o.50 tonne per tonne of the product. In spite of high cost of main raw material, the product has reasonably good profit margin. To start with, this route may be adopted but It is better to switch over to alternate process route based on bauxite as input material at the earliest with the funds generated from internal accruals. The capital investment for bauxite based sodium aluminate plant may be little higher because of requirement of additional equipment and facilities but the production cost will be very low. Thus the plant will be highly profitable with higher rate of return and low pay back period. The product is bagged in laminated HDPE bags for despatch to desired destinations.

Hope, the subject has been briefly covered in simple words for easy understanding. Please put your views / suggestions / remarks / comments, if any.

If you like this article, then please press your rating as  +1  .
Thanks and regards.

Kunwar Rajendra