JP6331035B2 - Method for producing iron source material using oil-containing dust sludge and method for treating oil-containing dust sludge - Google Patents

Description

  The present invention relates to a method for producing an iron source material using oil-containing dust sludge discharged in a production process of steel products and the like, and a method for treating oil-containing dust sludge. Specifically, the present invention relates to a method capable of efficiently removing oil from an oil-containing dust sludge and producing an iron source material without increasing the processing cost, and a method for treating the oil-containing dust sludge. .

  In steelworks, various iron and steel products are manufactured by reducing iron ore with coke to form hot metal and refining the hot metal into steel. When manufacturing such steel products, various sludges and dusts (containing iron as a main component) containing oil and moisture are discharged.

  For example, in the rolling process, various rolling lubricating oils, hydraulic oils, and greases are used to reduce the rolling load by reducing the friction coefficient, and to ensure the lubricity of the rolling mill and avoid the wear of the components. A large amount of iron-based sludge containing these oils is discharged (hereinafter, such oils and moisture-containing dust and sludge are referred to as “oil-containing dust sludges”). .

  The concentration of the oil contained in the oil-containing dust sludge varies depending on the process in which the oil-containing dust sludge is discharged, the type of rolling mill, and the like.

  Conventionally, the oil-containing dust sludge has been used as it is as a part of a granulated raw material for obtaining a sintered raw material.

  However, since the oil-containing dust sludge contains 20% by mass or more of oil as described above, the oil-containing dust sludge is charged when the sintered raw material of the pseudo particles after granulation is charged into a sintering machine and sintered. The oil contained in the sintered raw material vaporizes and adheres to the electrostatic precipitator and the bag filter, causing problems such as filter clogging and fire.

  Although attempts have been made to use oil-containing dust sludge as a steelmaking raw material for converters, the oil-containing dust sludge has a fine particle size and increases the amount of dust scattering, so it must be separately briquetted or pelletized. In addition to the inevitable inconvenience of rising costs, when steelmaking raw materials were charged into the converter, there was a risk that smoke would be generated due to the oil contained, or that a steam explosion would occur during pouring.

  As described above, if oil-containing dust sludge is used as it is, there are concerns about various adverse effects in terms of operation, and in fact, it is difficult to reuse as an iron-making raw material. The current situation is that the waste is disposed of by landfill.

On the other hand, some containing oil dust sludge contains a large amount of iron, to remove oil contained therein (dehydration, separation, roasting, etc.) to achieve reused as an iron source, so far Various studies have been made.

  For example, in Patent Document 1, in a method for treating oil-containing sludge using a co-current rotary kiln type heating furnace, it is necessary to burn the oil to a point where the oil in the oil-containing sludge evaporates in the furnace of the heating furnace. Air or oxygen-enriched air is forcibly blown, and the oxygen concentration in the exhaust gas on the outlet side of the heating furnace is controlled to 0.1 to 5% by volume. It is disclosed that after removing oil by burning under conditions where the inner wall surface temperature is 400 ° C. or higher, the sludge from which oil has been removed is cooled under non-oxidizing conditions.

  Patent Document 2 discloses that a high-pressure fluid is sprayed on oil-containing sludge in a rotor kiln, and the oil-containing sludge is dispersed in the form of small lumps of 1 to 10 mm on the inner wall surface of the kiln heated to high temperature. A method has been proposed.

Japanese Patent Laid-Open No. 10-169957 Japanese Patent Laid-Open No. 8-121736

  According to the method disclosed in the above-mentioned document 1, it is possible to completely burn only the oil content while limiting the combustion (oxidation) of the iron content in the oil-containing sludge as much as possible. Further, according to the above-mentioned document 2, it is possible to dramatically improve the combustion efficiency of oil-containing sludge having a low fluidity, which has a poor combustion efficiency. It was said that there was an advantage that the amount of coke oven gas) could be reduced.

  However, both of the above-mentioned documents 1 and 2 require not only large-scale equipment but also use fuel such as heavy oil for the treatment of oil-containing sludge. From the viewpoint of cost reduction and environmental conservation, it is preferable to reduce the amount of fuel used as much as possible. However, there is no mention of this point, and it has not been improved yet. There was room left.

An object of the present invention is to produce an iron source material by efficiently removing oil from oil-containing dust sludge without requiring large-scale equipment or increasing the amount of fuel such as heavy oil. there is to propose a processing method preparation and containing oil dust sludge.

  As a result of repeated studies to solve the above problems, in order to efficiently remove oil from the oil-impregnated dust sludge without increasing the amount of fuel used, bubbles are generated in the oil-impregnated dust sludge. The present inventors have found that it is extremely effective to use a foaming agent that separates and removes oil contained in oil-containing dust sludge. The present invention has been made based on this finding.

That is, the present invention provides a method for producing an iron source raw material using an oil-containing dust sludge containing at least one of a metal and a metal oxide, and 0.5 to 1 of water added to the oil-containing dust sludge. The oil content contained in the oil-impregnated dust sludge is separated and removed by the bubbles generated at that time, and the foaming agent set at a double amount and 0.5-5 times the amount of the oil-impregnated dust sludge is added. It is a manufacturing method of the iron source raw material using the oil-containing dust sludge characterized.

In the production method of the iron source material using the above-containing oil dust sludge,
1 ) The foaming agent is added to the oil-impregnated dust sludge after adding water 1 to 5 times the amount of the oil-impregnated dust sludge and stirring under conditions of 150 to 1000 rpm for 1 second or more and 10 minutes or less. Or being added during stirring,
2) the blowing agent, the concentration 5% by mass or more, and this is a less hydrogen peroxide 30 wt%, but preferably as a means for solving the problems. Here, the concentration in 2 ) is not only the concentration of the foaming agent itself, but also the concentration in the case where, for example, a liquid such as water is added to the oil-containing dust sludge and stirred, and the foaming agent is added thereto. Shall be included.

The present invention also relates to a method for treating oil-containing dust sludge that removes oil from oil-containing dust sludge containing at least one of a metal and a metal oxide . A foaming agent that is set to 5 to 1 times and 0.5 to 5 times the amount of oil-containing dust sludge, generates bubbles, and separates and removes oil contained in the oil-containing dust sludge by the bubbles. It is the processing method of the oil-containing dust sludge characterized by adding.

In the processing method of the above oil-containing dust sludge,
3 ) Add the foaming agent after adding 1 to 5 times the amount of oil-containing dust sludge to the oil-containing dust sludge and stirring at 150 to 1000 rpm for 1 second or more and 10 minutes or less. Or being added during stirring,
4 ) The foaming agent is preferably a hydrogen peroxide solution having a concentration of 5% by mass or more and 30% by mass or less as a specific means for solving the problem.

  According to the method for producing an iron source material using oil-containing dust sludge having the above-described configuration, the foaming agent is directly added to the oil-containing dust sludge to be treated, and is contained in the dust sludge due to fine bubbles generated at that time. The oil component can be pressurized and floated, thereby producing an iron source material with a reduced oil concentration without requiring large-scale equipment or increasing the amount of fuel used such as heavy oil. Is possible.

  Further, according to the method for producing an iron source raw material using the oil-containing dust sludge of the present invention, by using hydrogen peroxide water as a foaming agent, the metal and / or metal acid oxidation contained in the oil-containing dust sludge is increased. Since the product functions as a catalyst, it is possible to generate a very large number of bubbles as compared with the case where it is added to a material that does not contain metal and / or metal oxide, and oil can be efficiently removed.

Moreover, according to the processing method of the oil-containing dust sludge of this invention, an oil component can be efficiently removed from oil-containing dust sludge by simple operation which only adds a foaming agent.

It is the figure which showed typically the suitable equipment used for implementing this invention.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
Figure 1 is a schematic diagram showing a preferred equipment for carrying out the processing method of the preferred equipment, or containing oil dust sludge to produce an iron source material using the oil-containing dust sludge present invention .

  Reference numeral 1 in the figure denotes a container for treating oil-containing dust sludge. The lower side wall of the container 1 is provided with a discharge port 1a for taking out the treated dust sludge, that is, dust sludge that can be used as an iron source material, from the container 1.

  2 is a supply unit for supplying oil-containing dust sludge into the container 1, 3 is a supply unit for adding a foaming agent to the oil-containing dust sludge supplied into the container 1, and 4 is supplied into the container 1. It is a stirrer which stirs the oil-containing dust sludge.

  In order to remove the oil contained in the oil-containing dust sludge, the oil-containing dust sludge is supplied to the container 1 together with water through the supply unit 2 and stirred by the stirrer 4, and a foaming agent is added from the supply unit 3 during or after stirring. do it.

  By adding the foaming agent, fine bubbles are generated in the container 1, and the oil contained in the oil-containing dust sludge is separated by the bubbles, and the bubbles attached to the oil overflow from the container 3 and the system It will be discharged outside.

  The dust sludge from which the oil has been removed has a large specific gravity and settles down to the lower part of the container 1 and is discharged from the discharge port 1a.

The addition amount of the foaming agent, the water added to the oil-containing dust sludge, and 0.5 to 1 times. The amount of blowing agent is 0.5 to 5 times the oil-containing dust sludge, which is, by adding a blowing agent in this range, can be brought into contact with the blowing agent throughout the oil-containing dust sludge This is because the oil concentration can be reduced.

  As the timing for adding the foaming agent, add water 1 to 5 times the amount of oil-containing dust sludge and add after stirring under conditions of 150 to 1000 rpm for 1 second or more and 10 minutes or under stirring. According to this, since the foaming agent can be uniformly contacted over the entire oil-containing dust sludge, air bubbles can be generated throughout the oil-containing dust sludge.

  In the present invention, it is desirable to use hydrogen peroxide water as a foaming agent because the oil-containing dust sludge contains a large amount of metal and / or metal oxide. In addition, the bubbles generated when the metal oxide acts as a catalyst are much larger than those containing no metal and / or metal oxide, and the effect of removing the oil contained in the oil-containing dust sludge is effective. Because it becomes higher.

  The concentration of the hydrogen peroxide solution is preferably 5% by mass or more and 30% by mass or less. The reason is as follows.

  That is, when the concentration of the hydrogen peroxide solution is less than 5% by mass, there is a concern that the oil content in the oil-containing dust sludge cannot be efficiently removed. On the other hand, when the concentration exceeds 30% by mass. This is because there is a concern about an increase in cost (because hydrogen peroxide water is always used in the treatment of oil-containing dust).

  Here, many commercially available hydrogen peroxide solutions have a concentration of 30% by mass or less, and even if a commercially available hydrogen peroxide solution is used, a sufficient effect is obtained for removing oil. Therefore, it is not necessary to use hydrogen peroxide solution having a concentration higher than that of the commercial product, which is feared to increase the cost.

  As the foaming agent, sodium hydrogen carbonate, ammonium carbonate or the like can be used in addition to the hydrogen peroxide solution.

  In the present invention, the case of producing the iron source raw material using the oil-containing dust sludge discharged at the steelworks, or the case of processing the oil-containing dust sludge discharged at the steelworks, the present invention, It is also possible to apply oil-containing dust sludge discharged by processes other than the steel industry, and the present invention is not limited to oil-containing dust sludge discharged from steelworks.

  Oil-containing dust sludge (oil-containing dust / oil-containing sludge) contains metal and / or metal oxide and oil or water, and is discharged in various processes in the production of various products. Among these, oil-containing dust sludge containing iron and / or iron oxide is advantageous in that the oil content can be efficiently removed by the method of the present invention. Such oil-containing dust sludge is used for steel products that perform from steelmaking to rolling. It is discharged in various processes in manufacturing.

  The iron source material produced according to the present invention or the dust sludge treated according to the present invention has an oil concentration of less than 1% by mass and should be used as it is as a part of the granulated material when producing the sintered material. In addition to being capable of being used as a raw material for converter steelmaking, it has the advantage of not causing any trouble in operation.

  The container of the equipment shown in FIG. 1 is replaced with a beaker, and oil-containing dust sludge (see Table 1 for oil concentration) generated in an ironworks is charged into this beaker, and water is added to the beaker with a stirrer. While stirring, a foaming agent was added, and after standing for a while (until no bubbles were generated), the floating oil was removed and the residue in the container was collected and the concentration of the oil contained therein was investigated. The results are shown in Table 1 together with the results of processing by methods other than the method of the present invention.

  The oil concentration of the dust sludge after the treatment was measured by a normal hexane extraction method (JIS K0101 or JIS K0102).

  Usually, the dust sludge that can be used as the iron source material has an oil concentration of approximately 1% by mass, but in Examples 1-4 of the present invention, all are about 0.8 to 1.0% by mass, It was confirmed that it can be used sufficiently as an iron source material.

  On the other hand, Comparative Examples 1 and 2 each had an oil concentration of 1% by mass or more and were difficult to use as an iron source material.

  According to the present invention, it is possible to apply a method capable of producing an iron source material from oil-containing dust sludge without requiring a large facility or increasing the amount of fuel such as heavy oil. Moreover, according to this invention, the processing method which can remove efficiently the oil content contained in oil-containing dust sludge can be provided.

DESCRIPTION OF SYMBOLS 1 Container 1a Outlet 2 Oil supply dust sludge supply part 3 Foaming agent supply part 4 Stirrer

Claims (6)

In a method for producing an iron source material using an oil-containing dust sludge containing at least one of a metal and a metal oxide,
To the oil- containing dust sludge, a foaming agent set to 0.5 to 5 times the amount of water added to the oil-containing dust sludge and 0.5 to 5 times the amount of the oil-containing dust sludge is added. A method for producing an iron source material using an oil-containing dust sludge, wherein oil contained in the oil-containing dust sludge is separated and removed by generated bubbles. The foaming agent is added to the oil-containing dust sludge after adding water 1 to 5 times the amount of the oil-containing dust sludge and stirring under conditions of 150 to 1000 rpm, 1 second or more, within 10 minutes, It adds during stirring, The manufacturing method of the iron source raw material using the oil-containing dust sludge of Claim 1 characterized by the above-mentioned. The method for producing an iron source material using oil-containing dust sludge according to claim 1 or 2 , wherein the blowing agent is a hydrogen peroxide solution having a concentration of 5% by mass or more and 30% by mass or less. An oil-containing dust sludge treatment method for removing oil from an oil-containing dust sludge containing at least one of a metal and a metal oxide,
The oil- containing dust sludge is set to 0.5 to 1 times the amount of water added to the oil-containing dust sludge and 0.5 to 5 times the amount of oil-containing dust sludge, and is contained in the oil-containing dust sludge by bubbles. A method for treating oil-containing dust sludge, characterized by adding a foaming agent for separating and removing oil. The foaming agent is added to the oil-containing dust sludge after adding water 1 to 5 times the amount of the oil-containing dust sludge and stirring under conditions of 150 to 1000 rpm, 1 second or more, within 10 minutes, The method for treating oil-containing dust sludge according to claim 4 , wherein the oil-containing dust sludge is added during stirring. The method for treating oil- containing dust sludge according to claim 4 or 5 , wherein the foaming agent is a hydrogen peroxide solution having a concentration of 5% by mass or more and 30% by mass or less.

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