Method for recovering and purifying argon gas from single-crystal-silicon production device, and device for recovering and purifying argon gas

The present invention is a method for recovering and purifying argon gas from a single-crystal-silicon production device and a device for recovering and purifying argon gas, the method for recovering and purifying argon gas comprising a step in which waste argon gas, from a single-crystal-silicon production device, containing nitrogen, oxygen, and carbon monoxide is introduced into a waste-argon gas storage tank, a step in which solid matter contained in the waste argon gas is removed with pretreatment equipment for removing the solid matter, a step in which by catalytic reactions, the oxygen and the carbon monoxide are converted into water and carbon dioxide, respectively, and a step in which the water, the carbon dioxide, and the nitrogen are removed to obtain a recovery gas, wherein the catalytic reactions are made to proceed only with compressive heat by placing a catalyst in a two-stage compressor and, in the step of obtaining a recovery gas, the water is removed beforehand with a drier and thereafter the nitrogen and the carbon dioxide are adsorptively removed in a normal-temperature adsorption tower. Due to the method for recovering and purifying argon gas, impurity gases contained in the argon gas discharged in a large amount from a single-crystal-silicon production device can be stably removed using simple and inexpensive equipment.