Experiment Research On The Biomass Pyrolysis And The Reduction Of Copper Slag By Biomass

In face of the exhausted resources and increasing environmental problems,our country is challenged both by the resources and the environment.As an important part of non-ferrous metallurgy industry,copper smelting is an industry of intensive energy and resource.The sources of energy and resource waste seriously and the the problems of environment is especially serious.Aiming at the problems of low efficiency of waste heat recovery and the high energy consumption of the iron in copper slag recycle process,based on metallurgical slag granulating technology,a kind of biomass reduction-slag granulating-copper slag waste heat recovery technology is put forward in the paper.Based on the biomass reduction process,biomass pyrolysis characteristics and fixed carbon reduction characteristics of copper slag are researched in this paper,the results are as follows:?1?The process of Biomass pyrolysis and the reduction of copper slag were analyzed.The main chemical reactions of slag reaction system were calculated.Based on the coexistence of slag structure theory,the calculating model of mass action concentrations for CaO-FeO-Fe₂O₃-SiO₂ slag system was established in this paper.Through the calculating model,the study found that the addition of CaO can change the balance of copper slag system and CaO can promote the separation of iron and silicon.?2?By the thermogravimetric experiment,we found that:with the increase of heating rate,the rate of weight loss increased gradually;biomass particle size have little impact on the biomass pyrolysis process;the temperature range of biomass pyrolysis related to the biomass components;when the content of lignin is high,the range of pyrolysis temperature will increase;copper slag has little influence on the process of biomass pyrolysis.?3?Through the experiments of biomass pyrolysis,we found that:the main components of biomass pyrolysis gas are CO,CO₂,CH₄,and H₂;copper slag can promote the reaction of pyrolusis the cracking reaction of alkanes/alkene in pyrolysis gas;and thus copper slag can enhance the production of the pyrolysis gas and promote the percentage of H₂ in the gas;the catalytic effect of copper slag on different kind of biomass is different and the catalytic effect on corncob is most significantly,the H₂ yield can increasing from 15%to 40%;under different ratio of copper slag,the effects of copper on pyrolysis is different;when the proportion of copper slag and biomass is 1:1,the catalytic effect is the most remarkable.?4?Wilh Coats-Redfern and Malek method,the dynamic model of un-reacted core?A2?of three kind of biomass is selected in this paper.According to the model the kinetic equations with its kinetic parameters are determined.The activation energy of pyrolysis process were analyzed by using the distributed activation energy model at the same time,the shape of activation energy distribution curve is different for biomasses studied in this paper.The activation energy distribution curve of corn cob is in the shape of "W",however the cure of pine sawdust and straw are in the shape of "U".?5?Experiment on the reduction of copper slag by fixed carbon produced from biomass pyrolysis is conducted.We found that:the effects of the reduction by three kind of biomass are different.The reduction efficiencies of copper slag are in an order from high to low,pine sawdust,corn cob,straw;with the increase of the addition of biomass,the reduction efficiency of copper slag is higher;besides,CaO can promote the reduction efficiency of copper slag;in the experiments,the effect of reduction efficiency is best in a ratio of 1:0.3 for CaO addition;the reaction of copper slag reduction follows the nuclear reaction model,and the kinetic equations with its kinetic parameters are determined according to the calculations experiment results.