No, there is no harmful gas produced, and it will not pollute the ground.
Refractory brick produce dust hazards if it is broken, It is also should be paid attention to that if is refractory brick containing chromium, which will easily produce Cr VI when met with water, Cr^6+ material produced by magnesia chrome bricks is difficult to be damaged in the environment, which in many cases will exist in nature for a long time, continue to endanger human health. Chromite, as the raw materials to make magnesia-chrome brick, often exists in the form of trivalence (Cr203), is not toxic, nor carcinogenic, but in the cement rotary kiln high temperature oxidation atmosphere, it reacts with alkali metal oxide in cement materials, will produce chromic acid and alkali acid which is harmful to people's health. There are MgOIn contained in broken magnesia-chrome bricks, whose water solution is weakly alkalinity and generally will not easily produce K2cr207. K2Cr04 is a kind of weak oxidaiblity chemical compound, which has high chemical stability. It is very difficult to be reverted to non-toxic trivalent chromium when it blends into the environment. In many cases, these chemical compounds containing Cr VIcompounds will exist in nature stably, causing long-term pollution to the environment. This kind of harm is sustainable. The second reason that is very serious is that the high grade chrome ore is less and less in the world, forcing refractory manufacturers to find and develop
