For the high temperature melting and solidification mode of chromium slag mixed burned with coal in cyclone furnace of power stations

the X-ray diffractometer(XRD)

the X-ray fluorescence spectrometre(XRF)and the inductively coupled plasma-optical emission spectrometer(ICP-AES)were applied to detect the samples

to investigate the migration and evolution behaviors of the chromium minerals during the co-combustion of coal and chromium slag.The results show that

nine kinds of chrome minerals before combustion transferred to five kinds of other chrome minerals after high temperature melting

and finally became two kinds of chrome minerals

CrOCl and KCr3O8.The concentration of Cr~(6+)in the bottom slag decreased from 3 772μg/g to 4.60μg/g

which satisfies the criterion of ash/slag emission.In high temperature melting process

the chromium ion combined with the halogen elements Cl and F firstly

this may be because the halogenated compounds of chromium have lower boiling points.In order to increase the conversion of Cr~(6+)to Cr3+

the deoxidization and acid atmosphere should be kept in the combustion area to make the intermediate products Cr2O3 form as much as possible.