| China is a large industrial country in the world,and with the continuous development of industry,the particulate matter emitted during industrial production has caused serious damage to the ecological environment on which people depend,and has adversely affected human health and life,which has caused widespread concern from all walks of life.However,the rough development of China’s rare earth industry in the early stage has led to the defects of pollutant management in the process of rare earth production and the poor purification effect of waste gas.Especially,there are problems in the exhaust gas management of Pr-Nd metal blasting process such as difficulty in meeting the standard emission of particulate matter,flammable and explosive.Therefore,this study takes the Pr-Nd metal shot blasting process in rare earth industrial production process as the research object,analyzes its exhaust gas characteristics and current problems,and proposes corresponding optimization solutions.Since the existing tail gas treatment equipment is difficult to remove particulate matter efficiently,this study introduces Cloud-Air-Purifying technology,which is a new wet dust removal technology combining atomization saturation control,heterogeneous condensation and three-stage supergravity field,and has demonstrated its efficient removal capability for fine particulate matter and gaseous pollutants in previous studies.In this study,the Cloud-AirPurifying technology was applied to the treatment of tail gas of praseodymium blasting process in a rare earth company in Gansu Province to achieve efficient purification of particulate matter.Firstly,the collected particulate matter was analyzed in the experiment,such as physical phase composition and elemental composition,and it was found that the particulate matter contained Pr-Nd metal oxides and fluoride,which had certain toxicity and had adverse effects on the surrounding environment and human health.To address the problem of particulate matter fugitive and work environment pollution in the plant shop,simulation tests were conducted to analyze the flow field environment of the shot blasting machine exhaust collection device.Combined with the characteristics of particulate matter,the changes of the dust collection ducts on the particulate matter collection efficiency under different conditions of dust collection parameters were analyzed.Subsequently,for the problem that the particulate matter cannot reach the standard emission stably,combined with the environmental conditions of the plant site,analyzed and compared the advantages and disadvantages of the existing traditional dust removal technology solutions,and finally applied the Cloud-Air-Purifying technology to the treatment of Pr-Nd metal blasting exhaust gas,combined with the dust collection parameters obtained from numerical simulation,designed and arranged the Cloud-Air-Purifying system,and carried out the pilot texts.The results show that with the increase of pressure drop and atomization water volume,the dust removal efficiency of the Cloud-Air-Purifying system shows a trend of rising and then falling,and the optimal operating conditions of the system are 1.70 k Pa pressure drop,100 L/h atomization water volume and 99% particulate removal efficiency,and the outlet concentration is less than 10 mg/m~3.In addition,an experimental study was conducted on the treatment of wastewater generated during the dust removal process,and it was found that after reusing the wastewater,the particle removal efficiency of the Cloud-Air-Purifying system was basically unchanged,and the outlet particle concentration was stable below 10 mg/m~3.Finally,the Cloud-Air-Purifying system and the original bag type de-dusting system of Pr-Nd metal blasting process are compared and analyzed in terms of removal efficiency,economic efficiency and environmental efficiency,and it is concluded that the Cloud-AirPurifying system has obvious advantages and can replace the original bag type de-dusting system,and then the tail gas of Pr-Nd metal blasting process can be effectively treated. |
PDF Full Text Request