Study On The Removal Of Chromate From Aluminum Residue Containing Chromate

Adopting calcium free roasting produces chromate process byproduct aluminiummud which contents high aluminium. Because of it contains a amount of soluble and nonsoluble Cr, seriously affecting its subsequent utilization.With the country’s increasinglystringent environmental requirements, the deepening of enterprise circular economy andthe improvement of resource utilization, aluminum residue containing Cr purification andutilization has become a trend.In this article, based on the analysis of physical and chemical properties of aluminumsludge, characterized by the presence of Al and Cr in the form of aluminum residuecontaining chromate. From nine kinds of glue solution(numbers were1#,2#,3#,4#,5#,6#,7#,8#and9#) selected five glue solution, studied in detail of the solid-liquid ratio,glue solution dosage, mixing time, temperature and pressure,frequency on the Cr removesfrom aluminium chromium mud effects, the main research results are as follows.(1) After washing experiments and XRD, XRF, FT-IR characterization analysisshowed that mostly Cr in the form of soluble adsorption CrO42-on aluminum sludgesurface, while a small portion is wrapped in aluminum mesh mud structure.(2) Solid-liquid ratio, dosage and stirring time are not the main factors influencingthe separation of aluminium sludge. Glue solution of1#,2#and6#should choosesolid-liquid ratio at1:5and7#at1:15. The dosage of1#and2#should choose25g/kg,while6#and7#should choose50g/kg. The stirring time of1#and6#should beone hour,while2#and7#should be two hours.(3) Raising the temperature and increasing the number of plastic solutions areconducive to the separation of chromium. After analysis, the1#and2#should choose120℃,while6#and7#should choose130℃.With3#glue solution after four peptizationCr residue is less than0.05mg/g.(4) After XRD analysis, through1#,2#,6#,7#solution of the glue, aluminum mudtranslate clay colloid into pseudo boehmite γ-AlOOH.After3#solution of the glue, plasticaluminum is converted to aluminum phosphate.On the basis of experimental studies, combined with the actual production, puts forward the process about the removal of Cr from aluminum residue containing chromateand the process parameters of the process.