Research On Ventilation And Dust Reduction Technology Of Deep Open Pit Mine By Airflow Simulation

The dust problem in the open pit mine has long been in domestic and abroad.The dust generation and its dispersion has been the major concern in ambient air quality of deep cavities such as open cast mine.Uncontrolled fugitive dust emissions can present serious environmental,health,safety and operational issues impacting both site personal and wider community.Open pit mining operations have been identified as a major source of particulate pollution.Inhalation of particulate matter in respirable size(PM₁₀)generated during mining result of several diseases like black lung,asthma,cardiovascular diseases and lung cancer.The deep open pit mine is more difficult to solve dust problem.The controlling source of dust generation is an effective way,but it is relatively difficult.It is possible to study the distribution of dust and its elimination methods of technology and practice.The ventilation is a very effective means.The ventilation is divided into natural ventilation and mechanical ventilation.The natural ventilation have certain limitations of deep open pit mine.Therefore,mechanical ventilation is a possible solution to ensure safe operation and personnel health by the natural ventilation plus mechanical ventilation to solve the dust problem in the deep open pit mine.The main ventilation problems of case study BEIYA Gold Open Pit Mine as follows;this open pit mine is relatively deep,it is difficult to reduce the dust by relying on natural ventilation.There are many equipments used in the mine,resulting in more generating dust mining.BEIYA Gold Open Pit Mine has paid attention to the research of dust removal methods of many years,but the results are not good.BEIYA Gold Open Pit Mine blasted twice a day,causing a large amount of blasting dust.And the difficulty of land acquisition in BEIYA Gold Open Pit Mine,the mining realm cannot be in place at one time.And open-pit mining has a divestiture debt that caused the current operation of open pit mining that it is difficult to reduce dust in the mine pit.In order to study and solve the hazards of deep open pit mine dust,it is necessary to study the airflow patterns of natural and mechanical conditions.And suggestion the feasibility and measures for the natural and mechanical ventilation for apply to solve dust hazards in open-pit mine.The first step of research method is measurement of the natural ventilation condition of the BEIYA gold open pit mine.And the second step to design the BEIYA gold open pit mine 3D in the Gambit software and then simulation operation.This research was used CFD software to simulation the airflow patterns.The research studies as follows;the effects of different inlet air velocity factor to deep open pit mine condition.The effects of open pit ground temperature and inlet air temperature factors to deep open pit mine condition.The natural ventilation condition of BEIYA gold open pit mine.The effects of deep open pit mine size expanding on characteristics of airflow patterns of the deep open pit.The inputting one inlet air velocity tunnel at the middle bottom of open pit area for studies mechanical ventilation characteristics that maybe can apply to solving air and dust pollution in deep open pit mine.And adding the number of inlet air velocity tunnel at the bottom of open pit area,for studies the results of increasing number of wind velocities inlets to airflow patterns of deep open pit mine.The result of this research showed that;the increasing inlet air velocity into the pit will affect the depth levels of the wind into the pit,air velocity magnitude inside open pit and the air recirculation boundary that became larger and deeper.The air temperature into the pit was changed that will affect the temperature boundary of the air and the ground temperature in the pit.The natural ventilation condition of BEIYA gold open pit mine;in the morning period,the natural wind into the pit had the depth levels,air circulation and air velocity magnitude were lower than other periods.However,the characteristic of airflow patterns of all timed periods were found air recirculation turbulent inside the pit.The pit is larger and deeper that causes of dust ventilation out of the pit even worse.And the mechanical ventilation condition can result in reducing the air recirculation inside the pit that resulting in reducing dust accumulation within the pit but air velocity is relatively large and difficult to applying for actual situations.Therefore,this research is necessary to study the relationship between the increasing the number of inlet air velocity tunnel with air velocity that can be implementing and applying to practical situations.And the increasing number of inlet air velocity tunnels studies result showed that it can also reduce air velocity that inputting to open pit,which can reduce the inlet air velocity from 60 m/s down to the 10.7 m/s and still have effective reduces air recirculation within the pit.