NOVELTY - Firewood, grass and straw are processed to obtain mixed gas. Tail gas is passed through processing systems (A) and (B), and then to processing kettles. The tail gas in blast furnace is recycled and passed to processing system (C). Gas in processing kettles (A), (B) and (C) is pressurized, and activated by adding to activating kettle. Resultant product is pressurized to obtain liquefied gas, and obtained liquefied gas is packed. Gas which cannot be liquefied, is recycled and contamination-free gas is discharged. Thus, carbon dioxide in blast furnace tail gas is processed.    USE - Method for processing carbon dioxide in blast furnace tail gas.    ADVANTAGE - The method efficiently and economically processes carbon dioxide in blast furnace tail gas with reduced consumption of energy without affecting the environment.    DETAILED DESCRIPTION - Firewood, grass and straw are added to a three-component converting furnace and processed to obtain mixed fuel gas. The obtained mixed fuel gas is added to a system (A), extracted and heavy tar oil, electrical tar oil, water/oil mixed solution and light oil are separated by heavy tar oil extractor, electric tar precipitator, water/oil separator and light oil separator. The obtained tail gas is added to an oxygen removing system for removing oxygen and added to processing kettle (A). The obtained high-temperature cracked gas is added to a processing system (B), extracted and heavy tar oil, electrical tar oil, water/oil mixed solution and light oil are separated. The tail gas is added to oxygen removing system for removing oxygen and added to processing kettle (B) after processing. The tail gas of blast furnace is recycled by thermal insulating pipe, and added to a processing system (C). The resultant product is extracted and heavy tar oil, electrical tar oil, water/oil mixed solution and light oil are separated. The mixed gas in processing kettles (A), (B) and (C) are processed by compressors, and passed to an activating kettle. The mixed flammable gas is activated and pressurized in middle-pressure compressor. The obtained gas is added to a liquefying separation kettle to obtain flammable liquefied gas of high purity in the lower portion of the liquefying separation kettle. The obtained flammable liquefied gas is passed to a liquefied gas storage kettle, and gas which cannot be liquefied is recycled. The liquefied gas is passed to trucks or bottles, and the gas which cannot be liquefied is passed to a purifier. Calcium hydroxide solution in the purifier is filtered, such that carbon dioxide and sulfur dioxide are reduced to retained solid calcium carbonate and calcium sulfite. Tail gas containing nitrogen and nitric oxide, is released to the atmosphere. The solid mixture is separated from the purifier, and heated to decompose calcium carbonate into solid calcium oxide and carbon dioxide. The converted solid calcium oxide and calcium sulfite are added to a water tank, such that calcium oxide is converted into calcium hydroxide solution, and calcium sulfite is precipitated in the bottom of the tank. Calcium sulfite in the bottom of the tank is recycled, and calcium hydroxide solution is added to the purifier. Portion(s) of tail gas and solid substance solution are added to a detecting chamber. The tart oil extracted by heavy tar oil extractor and electric tar precipitator in the systems (A), (B) and (C), is added to a tar oil processing tank. Light oil separated by light oil separator, is added to light oil processing tank. Water/oil mixed solution which is separated by water/oil separator, is added to systems (A), (B) and (C). Light oil is added to light oil processing tank, and water is added to water dephenolizing tank. The dephenolized water is added to water storage tank and stored. The tar oil from tar oil processing tank, is added to a coke furnace to obtain high-temperature cracked gas at 280-470 degrees C. The obtained high-temperature cracked gas is passed to fractionating tower, and mixed anthracene oil, mixed naphthalene oil and light oil are recycled at 300 degrees C, 170 degrees C and 25-35 degrees C, respectively. High carbon compound cracked at high temperature, is added to a primary tar tank, and carbon dioxide emission is prevented. Gasoline and diesel oil from light oil are continuously processed and extracted using mixed anthracene oil, mixed naphthalene oil and light oil. Steam obtained from steam portion of three-component converting furnace, is passed to steam portion for redistribution, and one portion is added to high-temperature zone (A), (B) and (C). Another portion is added to high-temperature cracking furnace of three-component converting furnace for decomposing. High carbon compound in the primary tar tank, is processed continuously using raw material of carbon fiber or synthetic fiber. Silicon carbide substance is formed in the three-component converting furnace, after closing an upper air outlet on high-temperature cracking furnace and opening a lower outlet. The formed silicon carbide substance is extruded under steam pressure of 0.2 MPa, conveyed to a silicon carbide processing tank, cooled and recycled. After finishing the process, the lower outlet and upper outlet are closed, and high-temperature cracking process of firewood, grass and straw is performed. The lower section of the burning furnace of three-component converting furnace produces plant ash after specified period, and resultant plant ash does not contain contaminant. The liquefied gas is decompressed, purified and stored in liquefied gas storage kettle to obtain ground natural gas with methane content of more than 99%. The ground natural gas is converted into compressed ground natural gas, and supplied to chemical industries, fertilizer plants and residents through pipe. The ratio of mixture of firewood, grass and straw dosage with respect to carbon dioxide processing amount is 1:1-1.5. Thus, carbon dioxide in the blast furnace tail gas is processed.