| A novel process for the treatment of hazardous waste chromium slag(CS), based on self propagating reaction, was proposed in this paper.Based on the basic characteristics analyse of CS, the effectiveness of non-hazardous process under thermit recation and magnesium thermit recation were investigated; and the immobilization mechanisms of chromium were studied, the properties of the combustion wave under magnesium thermit recation were also explored. The results were significant in scientific and practial value, and the following creative results have been achieved:(1) CS is a hazardous waste whose toxic leaching concentration are far higher than the domestic environmental standards limit.So CS must be disposed.(2) CS become non-hazardous after SHS reaction. The final products can be entered into the indust rial solid waste landfill site or the domestic garbage landfill site under appropriate material ratio.(3) The detoxification rate of hexavalent chromium was found as high as 99.61%. Hexavalent chromium was reduced to lower valent state chromium during the SHS reaction, then encapsulated in the self propagating production by chemical and physical immobilization.(4) The maximum combustion temperature and combustion wave velocity decreased with the increase in CS amount and has a good linear relationship, the R-square of fitting curve is more than 0.91. The research work of this paper has guiding an d reference function for the disposal of chromium slag. The research results are of strong advance and practicability, which will create economic performance and social benefits as well as potential application value. |
PDF Full Text Request