The strength of castable containing MA spinel was better than that of the one contaning chrome ore.

And the test shows that the using condition of modified zirconium spinel brick is more bad than direct-bonded magnesia brick but as for chrome periclase-spinel compound brick (LYC) it is better.

These chrome free bricks include dolomite bricks, magnesia spinel bricks and magnesia calcium zirconate bricks.