Burning Municipal Waste Cement Kiln Lining, Cement Performance And The Impact Of Heavy Metals Leaching

There is a new trend around the world to dispose urban waste by means of cement rotary kiln. However, mentioned to the imperfect technology and high cost of matched equipment, what's more, problems also exist in the performence of cement,production process,twice pollution when urban waste are utilized, the technology has not been widely used. This article takes sorted urban waste into research, analyzes the feasibility of disposing urban waste by means of rotary kiln, researches the influence of calcining urban waste to kiln lining refractories,cement strength and calcining act,heavy metal lixiviation in clinker and hydrated product, conclusions from the experience results are as follows:(1) By throwing the sorted urban waste into calciner directly, calciner lining refractories, generally high-alumina brick, osculated the mixture of waste and material at high temperature, after keeping it at 1300°C for 5 hours, we haven't observed corrosion for material mixed with less than 20% waste. Meanwhile, pure waste can corrode the brick a little, with little new phase appearring and corroded layer depth 0.5mm～1mm. It is better to insure the waste ratio less than 20%.(2) Never unfavorable influence to clinker calcining by disposing urban waste, on the contrary, it can help to improve the burnability of material appropriately.(3) Contrasted to cement by pure raw material, it have higher strength than it by mixture, especially earlier strength. It has no unfavorable influence to cement strength by disposing urban waste.(4) The hydrated product from disposing urban waste have nice growth and natural development, which has compact hydrated structure.(5) From the experiment results, sorted urban waste has lower lixiviating quantity than others dangerous waste. After clinker calcined and cement hydrated, from the 20% waste cement 28d hydrated product, there is no Cd,Co,Ni,Pb lixiviated, meanwhile As,Cr,Cu,Zn little lixiviated, with the lixiviating quantity As: 0.0092mg/L, Cr: 0.0095mg/L, Cu: 0.0080mg/L, Zn: 0.0095mg/L, which is under the standard a lot and safe to environment.