Study On The Prevention And Control Of High Sulfur Coal Pile Spontaneous Combustion By Aciditithiobacillus Ferrooxidans Desulfurization

The sulfur content in coal is an important internal factor that leads to spontaneous combustion accidents in the process of coal storage and transportation.Spontaneous combustion of coal will not only cause waste of resources and threaten the safety production of coal enterprises,but also produce a large amount of toxic smoke,release CO,SO₂,H₂S,nitrides and other harmful substances to pollute the environment and seriously harm people’s health.This paper takes spontaneous combustion of coal pile as the research background,takes solid-liquid-gas-bacteria interaction as the theoretical basis,and aims to improve the desulfurization rate of coal,and carries out relevant research on the prevention and control of spontaneous combustion of coal pile by microbial desulfurization.The main research results are as follows.The mine water was collected as microbial stock solution,which was enriched,purified and cultured,and high purity strains were obtained for desulfurization experiment.Microbial acclimation experiment was carried out,and strains with good desulfurization effect and strong tolerance were cultivated.The effects of different initial Fe²⁺concentration,p H value,temperature and other factors on microbial growth were investigated by shaking experiments,and the optimal growth conditions were determined.Based on the conversion rate of Fe²⁺,the growth kinetics of microorganisms was analyzed.The Plackett-Burman（PB）experimental design method was used to carry out the shaking experiments of microbial desulfurization under different combination conditions,and the important factors affecting microbial desulfurization were obtained.Based on the steepest climb test and response surface analysis,the optimal experimental conditions for microbial desulfurization in the shaking experiment were determined.The research and development of microbial cultivation and microbial desulfurization continuous operation in one of the experimental equipment,breaking through the previous experimental equipment of microbial cultivation and desulfurization experiment can not be carried out at the same time,the continuous growth and propagation of microbial culture and microbial desulfurization operation together,shorten the experiment period,save the cost of the experiment.Combined with the orthogonal experimental design,the effects of different coal particle size,distribution strength,solution p H value and other factors on the removal of sulfur in coal blocks were investigated,and the optimal experimental parameters of microbial removal of sulfur in coal blocks were determined.X-ray diffraction and Fourier infrared spectroscopy were used to obtain the surface chemical components of coal samples before and after microbial desulfurization,revealing the influence of microorganisms on the chemical properties of coal samples.The surface morphology of coal before and after desulfurization was obtained by electron microscope scanning technology,and the intervention mechanism of microorganisms on the evolution of coal surface fine characteristics was clarified.The spontaneous combustion point,calorific value and activation energy of coal before and after desulphurization were obtained by thermogravimetric experiment of coal sample,and the influence rule of microorganisms on the change of thermal and physical properties of coal sample was determined.The interaction between microorganisms and gas phase was analyzed,and the electron transfer path and the formation process of micro-energy in microbial desulfurization process were clarified.The contact-reaction pathway between microorganisms and solid phase was analyzed,and the interaction mechanism between microorganisms and coal was determined.The process of redox reaction between microorganism and coal was analyzed and the mechanism of ion concentration variation in solution of microbial desulfurization system was obtained.The change of microbial concentration and kinetics of desulfurization were analyzed,the control model of microbial desulfurization was obtained,and the main factors restricting the desulfurization rate were determined.Numerical simulation software was used to analyze the desulfurization effect of microbial spray coal pile,and the influence law of microbial solution on inorganic sulfur content of coal pile was explored.The distribution law of temperature field inside coal pile before and after microbial solution spraying was obtained,and the response mechanism of spontaneous combustion characteristics of coal pile to microbial desulfurization was determined.It provides a theoretical basis for using microbial desulfurization technology to prevent spontaneous combustion of coal pile.The paper has 77 figures,34 tables,and 217 references.