Research On Producing Poly Aluminum-Ferric Chloride With Red Mud

Red mud is the waste in the process of producing alumina, the metal resource of which is rich, such as ferric oxide and alumina etc. Red mud occupies much ground and pollutes environment, so how to make use of ferric oxide and alumina in red mud are especially important nowadays when resource is going short. Poly aluminum-ferric chloride (PAFC) is an excellent purifing agent which fetures in little dosage, strong absorb ability, big floccule, fast sedimentation rate and so on. Therefore, porducing PAFC with red mud has expansive market foreground and environmental benefit.In this essay, PAFC with different degree of polymerization was synthesised by the method that hydrochloric acid directly immersed red mud through varying condition of acid soaking and pH value in usual pressure. The effects of concentration of hydrochloric acid, mol ration of hydrogen chloride of hydrochloric acid vs ferric oxide and alumina, acid soaking time, acid soaking temperature on leaching efficiency of ferric oxide and alumina were investigated in this experiment, and the effects of pH value on basicity of products were done. The products were tested by scanning electron microscope, X-ray diffraction and infrared spectrometer. In addition, the purifying performence of the production was researched respectively by treating kaolin waste water and dye waste water, and the effects of the dosage and basicity of flocculant, pH value, concentration and temperature of waste water on efficiency of confusion were detected.It is concluded from the study that the favor process condition of acid soaking is that the concentration of hydrochloric acid is 6mol/L, mol ration of hydrogen chloride in hydrochloric acid vs ferric oxide and alumina is 6.5:1, acid soaking temperature is 109℃, acid soaking time is 60 minutes. The basicity of the production is 85.03%. The best pH value of polymerization is 3.5. The ideal condition of treating kaolin waste water is that the concentration of PAFC is 0.060-0.095g/L, pH value is 6.9-9.0, the concentration of waste water is 100mg/L, waste water temperature is 25℃, the basicity of production is 75% to 90%, and the removal efficiency of turbidity can be up to 97%; The ideal condition of treating dye waste water is that the concentration of PAFC is 0.175-0.344g/L, pH value is 6.8-7.8, the concentration of waste water is 50mg/L, waste water temperature is 25℃, the basicity of production is 65% to 90%, and the decolouration efficiency can be up to 98%.