The method of disposal of gaseous waste and emissions containing benzpyrene
(57) Abstract:Formed during the smelting of ferrous and non-ferrous metals benzpyrene continuously oxidize refractory-lined pipe high temperature torch using a catalyst. The air supplied in excess in the ratio of benzpyrene : air 1: (28-30). The process of neutralization takes place at lower temperatures, continuously, safely. The invention relates to metallurgy, in particular for melting ferrous and non-ferrous alloys, and can be used for the disposal of gaseous waste and emissions, contaminated with organic substances, in particular benzpyrene.During the smelting of ferrous and non-ferrous alloys in the composition of the charge includes waste metal chips and scrap. The chips are always contaminated cutting fluid (coolant), and the scrap is found Nagar oil. When preparing the mixture to melting and smelting coolant and sludge oils are subjected to a heat treatment in the range of 300-800oC. this Temperature interval are the temperatures of the maxima of the output of benzpyrene - the most active of the known carcinogenic substances. The formation of benzpyrene contributes to the lack of oxygen, always having a place smelting.
20H12, crystalline substance capable of waggonette at 20oC, evaporates at a temperature of 179oC (Harmful substances in industry, edited by N. In.Lazareva, T. 1, 1976). The maximum allowable concentration of benzpyrene according to GOST 12.1.005-88 0,00015 mg/m3according to GOST 12.1.007-83 he belongs to the 1st class of hazard, extremely dangerous.Smelting contaminated with organic substances discharge of material concentration in the air of working zone often exceed the MAC several times. This raises the risk of disease working and, when released into the environment, to the disease population. In addition, benzpyrene in normal conditions persists and accumulates in the human body, plants, water and soil.The known method of thermal treatment of waste gases particulate production by burning axial flow of fuel with a part of the air (V1) with a flow of high temperature gases and feed tangential flow of the mixture of exhaust gases from the other part of the air (V2). Fuel burn when the ratio of air flow rate of 1.5-2.0, exhaust gases are mixed with the other part of the air at about 100-500oC (RF Patent N 2027107, CL F 23 G 7/06, publ. 20.01.95).However, in the known method and the amount of air insufficient for complete oxidation of benzpyrene, and low temperature air heating 100-500oC, it must be at least 800oC.The closest in technical essence is a way of burning resin refractory to neutralization of benzpyrene by heating them with subsequent oxidation released from the refractory gases in the afterburner. Heating of the resin refractories are gas-oxygen flame with a temperature of at least 2000oC until a temperature on the surface is not below 600oC, the walls of the afterburner is heated to temperatures above 1000oC, Inuktitut there oxygen stream released from the refractory gases and dorogaya their oxygen flame with a temperature not less than 1300oC (RF Patent N 2053451, CL F 23 G 7/06, publ. 27.01.96).The disadvantages of this method are the following: high temperature process, 2000oC requires more resistant high-temperature materials; post-combustion is in the cell in the presence of oxygen, which complicates the process and makes it more dangerous.The problem solved by the invention of owls is the Technical result is to simplify the method and to increase its security at the expense of continuity and use air instead of oxygen.This result is achieved in that in the known method of disposal of gaseous waste and emissions containing benzpyrene, by oxidation of high-temperature torch, oxidation produces a continuous lined pipe using a catalyst, while serving the air in excess of the ratio benzpyrene : air 1:(28-30).In the proposed process is a continuous oxidation of benzpyrene in lined pipe, through the air supply, according to the following reaction:
C20H12+ 23O2= 20CO2+ 6H2O
For this purpose, the air supplied in excess in the ratio of benzpyrene : air 1: (28-30). Does not require special technical means for supplying oxygen, which makes the process safer and easier. Due to the excess air and the catalyst is a more complete neutralization of benzpyrene.The method is as follows. Gaseous wastes and emissions from the smelting of ferrous and non-ferrous alloys are served in the lined pipe. Oxidation of waste, such as benzpyrene, produces a continuous high-temperature torch at a temperature of 800-1200oC. At this stage, benzpyrene, mixing with the air, will burn to carbon dioxide and water concentration of benzpyrene in the emission spectral-luminescent method with preliminary extraction and thin-layer chromatography (Manual on control of air pollution. RD 5204.18889). The rate of emissions is determined from experimental measurements in the lined pipe.Calculate the amount of benzpyrene, which is in gaseous waste by multiplying the concentration of benzpyrene on the ejection velocity.The amount of air for complete oxidation of benzpyrene is determined by multiplying the mass of benzpyrene by a factor of 28. This factor is determined by calculation.The oxidation reaction of benzpyrene:
C20H12+ 23O2= 20CO2+ 6H20
< / BR>From the reaction equations, it follows that for oxidation of 252 g/mol benzpyrene will need 736 g/mol oxygen. Since air contains 21% oxygen for complete oxidation of benzpyrene will need: g/mol air. Find the ratio of air to benzpyrene Considering the utilization of oxygen 50%, the need for air oxidation of benzpyrene will be twice, 142 = 28.Thus, air must be submitted in the ratio of benzpyrene : air 1: 28. With a smaller ratio will not happen complete combustion of benzpyrene, and higher ratios are not technologically feasible.Example.Gaseous waste drying aluminum shavings before vimperator 800-1200oC. In the lining of the pipes were built of bricks and MnO2alternating them. The presence of a catalyst speeds up the process.Benzpyrene in emissions determined spectral-luminescent method with preliminary extraction and thin-layer chromatography. The concentration of benzpyrene - 11610-5mg/m3. The ejection velocity is 10 m3/s determined by experimental measurement, thus the mass of benzpyrene in the gaseous waste amounted to: 11610-5103600 = 41,8 mg/hThe amount of air for complete oxidation of benzpyrene determined by multiplying the mass of benzpyrene by a factor of 28.41,828 = 1170 mg/hFor complete combustion of benzpyrene serves the air taken in the ratio 1: (28-30).Thus, the proposed method allows to exclude benzpyrene from continuous emissions by at a lower temperature and more secure process. The method of disposal of gaseous waste and emissions containing benzpyrene, by oxidation of high-temperature torch, characterized in that the oxidation produces a continuous lined pipe using a catalyst, while serving the air in excess of the ratio benzpyrene : air 1 : (28 - 30).
FIELD: metallurgy; metallurgy of light metals; production of aluminum.
SUBSTANCE: proposed method includes heat treatment of aluminum oxide with carbon, obtaining aluminum vaporous subhalogenide followed by its evacuation from reaction zone, cooling and separation of metallic aluminum. Heat treatment with carbon is performed in melt of aluminum oxide with salts of haloid acids in presence of trihalogenide in production of vaporous aluminum subhalogenide per operation cycle. Besides that, vaporous aluminum subhalogenide is obtained from foam-and-liquid phase at intensive mixing of melt in gas lift unit.
EFFECT: reduced temperature of process; enhanced economical efficiency due to reduced power requirements.
2 cl, 1 dwg, 1 ex