JPH042374A - Treatment of organic chlorine compound solvent - Google Patents

Abstract

PURPOSE:To prevent poisonous substance to be discharged by introducing organic chlorine compound solvent into a converter with a hot metal or a molten steel stored in, via bottom blow tuyeres or the like, and by blowing oxygen gas into the converter to burn the organic chlorine compound solvent at a specific temperature. CONSTITUTION:In a converter 1 with a hot metal 4 stored in, the organic chlorine compound solvent 6 of trichloroethylene or the like is blown together with N2 gas for example, from bottom blow tuyeres 2, and at the same time, through an upper blow lance 3, oxygen is blown into, and a converter interior is kept at a temperature exceeding 1000 deg.C, and the organic chlorine compound solvent is burnt. As a result, the burning can be processed at a low cost without generating the poisonous substance of dioxine, phosgene, or the like, and with decomposition reaction under high temperature atmosphere in a bath and burning reaction near the surface of oxygen jet and a fire point, and chlorine gas or the like can be removed with a dust collecting device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for safely disposing of organic chlorine solvents such as trichlorethylene used for cleaning ICs (integrated circuits), etc. The present invention relates to a method for treating an organic chlorine solvent in which no toxic substances are generated by burning the organic chlorine solvent at a high temperature of 1000° C. or higher.

BACKGROUND OF THE INVENTION Organochlorine solvents such as trichlorethylene are used in large quantities for cleaning ICs in high-tech industries.

This is because trichlorethylene has an outstanding ability several times that of gasoline to remove oil adhering to integrated circuits.

However, on the other hand, trichlorethylene is carcinogenic, and when burned, it releases highly toxic substances such as chlorine, dioxins, and phosgene. Also, if it is left in a drum pipe or the like for many years or buried underground and dumped, the bottom will rot and the contents will flow out and be sucked into the ground. For this reason, in Japan, its discharge into groundwater as a toxic substance has been regulated (from October 1999).

By the way, organic chlorine solvents such as trichlorethylene
It is known that toxic substances such as dioxins and phosgene are not generated when burned at a high temperature of 000° C. or higher.

However, there are only about 30 companies in the country that can process organic chlorine solvents such as trichlorethylene, and there are cases of illegal dumping, which has become a major social problem. Moreover, there are many questions as to whether these processing companies are disposing of waste properly.

According to a survey by the Environment Agency, trichlorethylene, which is below water quality standards, was detected in 4.6% of wells, and tetrachlorethylene, which is the same organic chlorine solvent, was detected in 6.3% of wells.
The contamination is spreading across the country, with 0.4% of 1-trichloroethane detected, showing no signs of slowing down.

Problems to be Solved by the Invention As mentioned above, if organic chlorine solvents such as trichlorethylene are buried and dumped underground, contamination of groundwater becomes a problem. On the other hand, if it is not burned at a high temperature exceeding 1,000 degrees Celsius, toxic substances such as dioxins and phosgene will be generated.

For this reason, the treatment of organic chlorine solvents has to rely on high-temperature combustion methods of over 1000°C or chemical methods, which are expensive and cannot meet the demand for treatment. .

In view of these circumstances, the second invention proposes a method of burning organic chlorine solvents such as trichloroethane at a high temperature exceeding 1000°C at a fixed cost to prevent the emission of toxic substances. That is.

Means to solve the problem When disposing of organic chlorine solvents such as trichlorethylene using high-temperature combustion methods, it is necessary to burn them at high temperatures exceeding 1000°C in order to avoid generating highly toxic substances such as dioxins and phosgene. . However, it is extremely difficult to stably obtain a high temperature exceeding 1000° C. using a normal combustion furnace.

Therefore, the inventor focused on a converter for steel manufacturing and discovered that an organic chlorine solvent such as trichlorethylene can be burned at a high temperature exceeding 1000° C. using a converter.

As is well known, in a converter, hot metal at around 1300°C is charged and the carbon in the hot metal is burned with pure oxygen, so the temperature is always 130°C.
A combustion temperature of 00°C or higher is ensured. therefore,
Burning organic chlorine solvents such as trichlorethylene in a converter can prevent the generation of highly toxic substances.

Based on this knowledge, the gist of this invention is to introduce an organic chlorine solvent into a converter where hot metal or steel is stored through a bottom blowing tuyere, blow in oxygen gas, and burn it at a temperature exceeding 1000°C. It is a thigh.

Effect The combustion treatment temperature of organic chlorine solvents such as trichlorethylene was limited to a temperature exceeding 1000°C.
This is because toxic substances such as dioxins and phosgene are generated at temperatures below.

As a method for introducing the organic chlorine solvent into the converter, existing tuyeres or nozzles installed on the bottom of the furnace or the side wall of the furnace can be used.

The reaction of the organic chlorine solvent in the converter proceeds as follows.

■ Decomposition reaction CI H+n under high temperature atmosphere in bath
C1n=1-C+m-H+n-C1■ Combustion reaction on the surface of the oxygen jet and near the fire point C+1/20 = CO H2+1/202= Ht.

C+ 02 = CO2 Therefore, it can be decomposed or burned without generating substances such as dioxins and phosgene.

Here, as the organic chlorine solvent, in addition to trichlorethylene, the following are known.

Methyl chloride, methylene chloride, carbon tetrachloride, ethyl chloride,
Ethylene chloride, ethylidene chloride, trichloroethane, tetrachloroethane, perchlorethylene, pentachloroethane, hexachloroethane, bromochloroethane, allyl chloride, isopropyl chloride, propylene chloride, trichloropropane, butyl chloride, dichlorobutane, hexachloropropylene, Hexachlorobutadiene, amyl chloride, dichloropentane, 2-ethylhexyl chloride, chlorcosane, chlorobenzene, O-dichlorobenzene, trichlorobenzene, chlorotoluene, dichlorotoluene,
or a mixture of these.

Embodiment FIG. 1 is a schematic diagram showing an embodiment of the present invention, in which (1) is a converter, (2) is a bottom blowing tuyere, (3) is a top blowing lance, and (4) is a bottom blowing tuyere.
) indicates hot metal, (5) indicates slag, and (6) indicates an organic chlorine solvent such as trichlorethylene.

That is, a converter (1) in which an appropriate amount of hot metal (4) is stored is charged with an organic chlorine solvent (6) such as trichlorethylene.
) is blown in from the bottom blowing tuyere (2) together with, for example, Nt 2 gas, while oxygen is blown in from the top blowing lance (3) to maintain the inside of the furnace at a temperature exceeding 1000° C. to burn the organic chlorine solvent.

Example 1 Table 2 shows the results of combustion treatment of trichlorethylene (CHCI CC1,) under the blowing conditions shown in Table 1 in a small test furnace having the structure shown in FIG. 1 and having a processing capacity of 10 tons of hot metal.

For comparison, the combustion conditions and results when trichlorethylene was burned in a conventional combustion furnace are also shown.

As is clear from the results in Table 2, the conventional method requires a large amount of fuel (heavy oil), and in addition to high HCI in the exhaust gas, the low combustion temperature generates highly toxic substances such as dioxin and phosgene. On the other hand, in the present invention, since hot metal is used as a heat source, fuel (heavy oil) is unnecessary and economical, and dioxin and phosgene can be completely eliminated. Furthermore, HCI%Cl t in the exhaust gas is at most 250 ppm, which is less than half of the conventional method, and most of it can be removed by the existing wet type dust collector, so there is no problem.

As described in detail in Table 1 below, according to the method of this invention, organic chlorine solvents such as trichlorethylene can be combusted at low cost without generating toxic substances such as dioxins and phosgene. Furthermore, chlorine gas can be almost completely removed using existing dust collectors, making it extremely effective as a treatment method for organic chlorine solvents, and it is highly effective in preventing environmental pollution such as groundwater contamination caused by organic chlorine solvents. It is something to play.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an embodiment of the present invention. 1... Converter 2... Bottom blowing tuyere 3...
・Top blowing lance 4...Hot metal 6...Organic chlorine solvent

Claims (1)

[Claims] In a method of burning an organic chlorine solvent such as trichlorethylene at a temperature of 1000°C or higher, the organic chlorine solvent is introduced into a converter in which hot metal or molten steel is stored through a bottom blowing tuyere, etc., and oxygen gas is injected into the furnace. A method for treating an organic chlorine solvent, which comprises blowing the organic chlorine solvent into a tank and burning the organic chlorine solvent at a temperature exceeding 1000°C.