Non-Chloride Cement Accelerators

Electric arc furnace dust is a byproduct of the electric steelmaking industry and is produced in large quantities arormd the world (17). The safe disposal of such a byproduct is expensive and continues to be a serious concern in many countries throughout the world. A cement composition has been disclosed comprising (17,18)  

Exemplary non-chloride accelerators have been described. These are calcium nitrite and calcium formate (17). Calcium nitrite and calcium formate appear to provide additional sources of Ca and may thus reduce the time required to achieve supersaturation of the solution with respect to Ca(OH)2. Calcium nitrite can decompose into calcium oxide and a mixture of nitrogen dioxides according to following equation (17)  

The cement compositions containing electric arc furnace dust are capable of exhibiting an improved early compressive strength and workability (17). 

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E.M. Al-Mutlaq, Use of non-chloride cement accelerator and electric arc furnace dust in cement, US Patent 9278888, assigned to Saudi Basic Industries Corporation (Riyadh, SA), March 8,2016. 

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