Use of by-Pass Cement on the Production of Sodium Chromate from Pellets Containing Chromite Ore Concentrate and Soda Ash

Y.M.Z. Ahmed*, F.M. Mohamed, N.A. El-Husseiny and M.E.H. Shalabi

Central Metallurgical Research and Development Institute, P.O. Box: 87, Cairo, Egypt

Received 25 December 2002; accepted 12 May 2003


The amount of by-pass cement produced from Egyptian Cement Companies is more than 10% of the total cement production. This dust is harmful on the health of human beings especially for those living near the company. It is known that the preparation and crushing of the raw materials for cement production is a highly expensive step. Accordingly, decreasing the amount of dust reduces the production cost of cement per ton. Many investigations were carried out to solve this problem by recycling this dust in alternative processes (e.g. use it in the production of cement, clay bricks, or as a fertilizer by mixing it with sewage water). Recycling it with raw materials can only be carried out in the wet process of cement production. Unfortunately, up till now these solutions has not yet been sufficient. In this investigation, a trial is made to use such dust as catalytic material in the production of sodium chromate. In this investigation, two feed materials consist of the chromite ore concentrate and soda ash with and without cement dust addition was firstly pelletized and the properties of the produced pellets were examined. The suitable pellets (from its mechanical properties point of view) were subjected to firing process at different temperatures, then the roasted pellets were dissolved in hot water and the sodium chromate was extracted from it. Also this paper studied the kinetics of formation of sodium chromate for both pellet types.

Keywords: Cement; Pellet; Chromite; Soda ash

* Corresponding author
   E-mail : ahmedymz@hotmail.com