JPS63139038A - Use of dust, sludge, flue ash and slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention is applicable to dust and sludge generated from steelworks.
Items with a high iron content are used as raw materials for steelmaking, but dust, sludge, and vat are disposed of in landfills because they have a high iron content but have a lot of oil and moisture attached to them, or because they have a low iron content. Flue ash, which is disposed of in landfills because it contains only a small amount of useful metal oxides such as Co, and charcoal generated from drying ovens and boilers that use wood chip bark as fuel, can be used to produce iron for cement, calcium, It is used as an energy source.

(Conventional technology) Blast furnace dust discharged from a blast furnace is subjected to flotation treatment to recover coke powder and the rest is disposed of in a landfill, or it is separated into iron-rich parts and iron-poor parts using a wet cyclone method. However, the former is used as raw material for sintering, and the latter is incinerated or disposed of in landfills.

Among the sludge generated in the pickling process, lime-neutralized sludge and oil-containing sludge generated in other wet processing processes, those with high iron content are recycled into sintering raw materials after being dried in a rotary kiln, etc. However, the rest is disposed of in landfills.

The flue method used in oil-fired thermal power plants, etc. depends on the oil used, and may be rich in V, Ni, and Co, or contain very little, and the former is concentrated after incineration to produce V, Ni, and Co.
Although it is used as a recovered raw material such as Co, the latter is disposed of in a landfill.

Coal generated from drying furnaces and boilers that burn wood chip bark is also disposed of in landfills.

Steelmaking slag, desiliconization slag, desiliconization slag, etc. are crushed,
Iron grains are collected through magnetic separation and recycled as a raw material for steelmaking, but the remaining slag often expands and disintegrates, so after aging it is only partially used for roadbed materials, fertilizers, cement raw materials, etc. The majority of waste is disposed of in landfills.

(Problem that the invention attempts to solve) As mentioned above, dust generated from iron and steel manufacturing industries.

Sludge, oil-impregnated sludge, etc. have low iron content (T, F
Since it contains a certain amount of CI, Cd, Pb, Zn, etc., it is problematic to recycle it as a sintering raw material or use it as an iron source for cement.

Regarding the flue method, V depends on the type of fuel used.

When the content of Ni, Co, etc. is high but S is also high, V, L
There are cases where the content of +Go etc. is small and the S content is large, so there is a problem that it cannot be used effectively.

The present invention was made in view of these circumstances, and it
Unnecessary substances such as sludge can be removed by washing with water, boiling water, or acid treatment, and in the flue method, when washing with water or treating with mineral acid solution, the S content is reduced to 0.5 to 0.8%, and it is fixed. Carbon is 90-95% and has a generation amount of about 8,000 KcaI/Kg, and the slaked carbon generated from a drying furnace using wood chip bark as fuel is (:d, Pb, 7n.

It contains almost no C1, S, Na, O, etc., has a fixed carbon content of 75-80%, and has a calorific value of approximately 4,0OOKcal/Kg, so we conducted research with the idea that it could be used effectively as a cement raw material and an energy source for cement. The present invention has been completed by repeating the above steps.

When considering the iron source, cab, and 5ift source for cement raw materials, when cement is manufactured from raw materials containing a large amount of NaxO and C1 and used as concrete, problems such as alkali aggregate reaction and reinforcing steel corrosion may occur, and This is not preferable as it may cause the formation of

However, in the case of the above-mentioned dust sludge, slag, and flue method, there is very little Na0 richness, and as mentioned above, CI etc. can be easily removed by washing with water or treating with mineral acid solution. It can be used as an iron source + Ca O + SiOt + energy source for cement raw materials.

Furthermore, the slag generated during the steelmaking, desiliconization, and P-3 processes is C
ab, FezO*+ 5i02. AIzO*tl!
Since l is the main component, it is mixed with limestone, clay, silica stone, etc., and the hydraulic ratio is 2.10. Silicic acid rate=2.75. Iron rate = 1.70
If cement is manufactured by mixing limestone at a constant level, the amount of limestone added will decrease, and the energy required for the decarboxylation reaction will decrease.

Properly mixing the above dust, sludge, flue ash, charcoal, and slag will prevent the dry fine powder from scattering, and if there is too much moisture, the amount of moisture will be adjusted to the appropriate amount, and Ca ions eluted from the slag will become Ca (OH) z, and further It absorbs COz from the air and produces CaCO5, which solidifies and becomes easier to handle.
Altos can be effectively used as an energy source.

(Means for Solving the Problems) The present invention solves the above problems and opens the way to the effective use of dust, sludge, flue ash, charcoal, slag, etc. generated dust,
It is characterized by mixing two or more types of sludge, flue ash generated from an oil-burning furnace, charcoal generated from a furnace using wood chip bark as fuel, oil-containing sludge, pickling sludge, and steelmaking slag and using it as a raw material for cement. This is how dust, sludge, flue pressure, and slag are used.

In the above invention, collected dust and sludge.

The flue ash is washed with water or a mineral acid solution, and the slag is steelmaking slag or P-S-free slag, and the dust is collected.

Ferrous sulfate or ferrous chloride may also be added to the sludge.

(Examples and Effects) Examples and results carried out in order to demonstrate the effects of the present invention to bv t will be shown below. Dust used in the experiment.

The chemical analysis values of sludge, flue ash, slaked coal, and slag are shown in Table 1. They were washed with water, treated with a mineral acidic solution, etc. at a pulp concentration of 30%, and treated with a stirrer for 15.30 minutes for different treatment times. Dehydrated using a funnel. However, when treated with mineral acidic solution, the sample was further washed with water of the same weight as the sample amount. Since there is almost no difference in these values even if the time is changed, Table 2 shows the analytical values obtained after processing for 15 minutes.

As a result of the above, if the material contains a considerable amount of CI, Zn, Pb, Cd, etc. and is undesirable as a cement raw material, it should be washed with water, hot water, or mineral acid. It can be easily removed by treating with 8 liquids for about 15 minutes.

However, these dusts, sludges, etc. are often very fine and when dried, they become a source of dust and scatter.When mixed with slag, Ca ions eluted from the slag become Ca(01ri!), which further releases air into the air. It absorbs CO2 from inside and becomes CaCO*, which hardens and prevents the generation of dust.The mixed raw material is limestone.

Mixed with silica stone, clay, etc., the plain value was approximately 3 in a test ball mill.
,000cd/g, add water and knead about 10-15
Pellets of φ1 were made into pellets, placed in a platinum plate in an Elema electric furnace maintained at 1,450°C, fired for 30 minutes, cooled in air outside the furnace, and then made into a prototype Talinker. 4% gypsum trihydrate was added, and a test ball mill was used to reduce the plain value to approx. Table 3 shows the results of pulverizing to 3,150-/g, making JIS mortar (4 x 4 x 16 mm) according to the JIS method, and measuring the cement strength.

In addition, the calculation of the cement raw material is as follows: hydraulic ratio -2.10, silicic acid ratio = 2.75. Iron rate = 1.75. Limestone, silica stone, and clay, which are normal cement raw materials, have a gate go of 2.0.

No. 1, limestone when using karami and serpentine.

No. 2, limestone, silica stone when using silica stone, clay, steelmaking slag (slag ■), dust ■1 dust ■.

Cases using clay, steelmaking slag (slag ■), de-P-S slag (slag ■), washing of dust ■, sloughji ■, dust ■, and flue ash ■ are designated as No. 3, and prototype raw materials and prototype tallincar. And so.

According to the elution test method published by the Environment Agency, dust ■ contains 0.0I P, P, M? of Cr'° ions. However, if 0.1% of ferrous sulfate or ferrous chloride is added and mixed after watering, elution can be prevented. Therefore, limestone, silica stone, clay and P-S-free slag (slag ■).

Dust■ treated with 0.1% ferrous sulfate, sludge■
, the case where Dust ■ was used was designated as No. 4, and was used as a trial raw material and a trial production Talinker.

As mentioned above, it can be seen that by mixing dust sludge, etc., which had been disposed of as industrial waste in a landfill, with slag, it can be effectively used as a raw material for cement, with almost no change in the strength of cement.

In addition, materials containing C such as flue ash, blast furnace dust, and slaked coal were mixed, but the calorific value was approximately 3+500 to 8,000 Kc.
Although it has al/Kg, the amount of heat decreases because it is an experimental electric furnace! Not approved.

However, carbonaceous shale and waste tires are also used by cement manufacturing companies to reduce energy consumption, and I think this would be effective if done in an actual rotary kiln. In addition, flue ash, extinguished coal, etc. are not only mixed with cement raw materials and used, but also blown (supplied) from a device near the bottom of the suspension preheater device that blows pulverized coal, oil, etc. as combustion. Both have the same effect, so you can use either one.

(Effects of the invention) As described above, dust generated from the steel industry, etc., has problems because it contains too little iron or contains oil to be recycled as a raw material for steel production, and is disposed of in landfills as industrial waste. Sludge.

Slag or flue ash generated from power plants, etc., which is disposed of in landfills due to its low content of valuable metal oxides, can be used as an energy source, or it can be washed with water or cleaned with mineral acid solution. By doing this, C1, Pb, Zn, etc. which are undesirable for cement are removed, and Zn,
By recovering Pb, Cd, etc. as hydroxides, etc., and effectively using the residue as a raw material for cement, it is possible to extend the life of limited resources such as limestone and silica stone.

Claims (1)

[Claims] 1. Dust and sludge generated from steel mills, flue ash generated from oil-burning furnaces, charcoal generated from furnaces using wood chip bark as fuel, oil-impregnated sludge, pickling sludge, and steelmaking slag A method of utilizing dust, sludge, flue ash, and slag, characterized by mixing two or more of the following and using the mixture as a raw material for cement. 2. The dust, sludge, and flue ash set forth in claim 1, characterized in that the collected dust, sludge, and flue ash have been washed with water or washed with a mineral acid solution; How to use slag. 3. A method of utilizing dust, sludge, flue ash, and slag according to claim 1, wherein the oil-impregnated sludge contains iron. 4. The dust according to claim 1, wherein the slag is steelmaking slag or P/S-free slag;
How to use sludge, flue ash and slag. 5. A method of utilizing dust, sludge, flue ash, and slag according to claim 1, characterized in that the collected dust and sludge contain ferrous sulfate or ferrous chloride.