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X. Li et al.
purification and removal of fluorine and sulfur in electrolytic aluminum flue gas can
effectively solve the technical problems of aluminum electrolysis flue gas purification, and provide technical support for the realization of ultra-low emission in the
Chinese aluminum electrolysis industry [1].
At present, there are mainly limestone/lime gypsum washing method, sodium
alkali method, and ammonia method. In the limestone/lime gypsum washing method,
the pipeline is easy to scale and block, the wastewater is difficult to be treated, and
the gypsum quality is low. The sodium alkali washing method has high removal costs
and is difficult to be widely used. While the ammonia method has a wide application range, high desulfurization and defluorination rate, no secondary pollution,
and certain removal capacity for nitrogen oxides, which can realize the integrated
purification of fluorine and sulfur [2–4]. Xiang Gao [5] et al. studied the absorption
of SO 2 by ammonium sulfite in the ammonia-based process in power plants, and
studied the absorption reaction between sulfur dioxide and ammonium sulfite solution in a stirred tank reactor. Wang [6] et al. used ANSYS CFX software to conduct a
comprehensive gas–liquid two-phase flow field simulation study on a sintering flue
gas desulfurization tower, and established a detailed model to simulate the gas–
solid two-phase flow field in a large-scale ammonia WFGD tower. Dong Chengyong
[7] described the treatment of aluminum electrolysis flue gas by a company used
the limestone-gypsum wet method. The limestone slurry absorbed and reacted with
acid gases such as fluoride and sulfur dioxide to obtain a calcium salt mixture. At
present, there are still few studies on the synergistic removal of fluorine and sulfur
in the aluminum electrolysis flue gas . This article focuses on the problems of short
gas–liquid contact time, small mass transfer driving force, and low gas–liquid mass
transfer efficiency in the aluminum electrolysis flue gas. The physical simulation
was used to study the influence law of mass transfer coefficient in the chemical
reaction process of defluorination and sulfur removal from ammonia water. The
operation parameters and equipment parameters of different axial position, gas flow
rate, liquid flow rate, filler types, and sizes in the filled tower were studied, so as to
strengthen gas–liquid mass transfer and increase the gas–liquid reaction rate.
Experimental Equipment and Experimental Methods
Experimental Equipment
The physical simulation [8–10] was based on the similarity criterion and the establishment of the physical model based on the criterion that the modified Froude number
was equal. In this experiment, in the process of studying ammonia defluorination
and desulfurization, the physical model used a filled tower made of plexiglass, and
the system of NaOH-CO 2 was used to simulate the ammonia desulfurization system.
This experiment was based on the industrial data [11] of Yunnan Asia Pacific Environmental Design and economy Company with an annual flue gas treatment capacity
X. Li et al.
purification and removal of fluorine and sulfur in electrolytic aluminum flue gas can
effectively solve the technical problems of aluminum electrolysis flue gas purification, and provide technical support for the realization of ultra-low emission in the
Chinese aluminum electrolysis industry [1].
At present, there are mainly limestone/lime gypsum washing method, sodium
alkali method, and ammonia method. In the limestone/lime gypsum washing method,
the pipeline is easy to scale and block, the wastewater is difficult to be treated, and
the gypsum quality is low. The sodium alkali washing method has high removal costs
and is difficult to be widely used. While the ammonia method has a wide application range, high desulfurization and defluorination rate, no secondary pollution,
and certain removal capacity for nitrogen oxides, which can realize the integrated
purification of fluorine and sulfur [2–4]. Xiang Gao [5] et al. studied the absorption
of SO 2 by ammonium sulfite in the ammonia-based process in power plants, and
studied the absorption reaction between sulfur dioxide and ammonium sulfite solution in a stirred tank reactor. Wang [6] et al. used ANSYS CFX software to conduct a
comprehensive gas–liquid two-phase flow field simulation study on a sintering flue
gas desulfurization tower, and established a detailed model to simulate the gas–
solid two-phase flow field in a large-scale ammonia WFGD tower. Dong Chengyong
[7] described the treatment of aluminum electrolysis flue gas by a company used
the limestone-gypsum wet method. The limestone slurry absorbed and reacted with
acid gases such as fluoride and sulfur dioxide to obtain a calcium salt mixture. At
present, there are still few studies on the synergistic removal of fluorine and sulfur
in the aluminum electrolysis flue gas . This article focuses on the problems of short
gas–liquid contact time, small mass transfer driving force, and low gas–liquid mass
transfer efficiency in the aluminum electrolysis flue gas. The physical simulation
was used to study the influence law of mass transfer coefficient in the chemical
reaction process of defluorination and sulfur removal from ammonia water. The
operation parameters and equipment parameters of different axial position, gas flow
rate, liquid flow rate, filler types, and sizes in the filled tower were studied, so as to
strengthen gas–liquid mass transfer and increase the gas–liquid reaction rate.
Experimental Equipment and Experimental Methods
Experimental Equipment
The physical simulation [8–10] was based on the similarity criterion and the establishment of the physical model based on the criterion that the modified Froude number
was equal. In this experiment, in the process of studying ammonia defluorination
and desulfurization, the physical model used a filled tower made of plexiglass, and
the system of NaOH-CO 2 was used to simulate the ammonia desulfurization system.
This experiment was based on the industrial data [11] of Yunnan Asia Pacific Environmental Design and economy Company with an annual flue gas treatment capacity