JPS6034494B2 - Method for producing porous activated coke - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides semi-formed coke with a carbonization temperature of 400 to 900oC used in the steel industry for reducing iron ore to an inert gas containing 70,000 or more gases including oxygen (1% or less) and carbon dioxide, e.g. The present invention relates to a method for producing porous activated coke with excellent adsorption performance by performing child heating and primary activation using nitrogen gas, and then performing secondary activation using steam at a temperature of 800 to 90,000.

- Activated carbon is an adsorbent that has been widely used industrially.

This activated carbon is manufactured by using coal, petroleum pitch, chassis shell, wood, etc. as starting materials through a carbonization process and an impregnation process. At this time, a large amount of energy is required, and since all of these raw materials are expensive, it is inevitable that the activated carbon obtained will also be expensive. The present invention provides an inexpensive and high-quality adsorbent by taking into account these conventional drawbacks, utilizing carbon materials and waste heat energy used in the steel industry, and performing a new activation process. . In other words, the blast furnace charge for the purpose of reducing iron ore is optimally prepared by using semi-formed coke as a starting material from among the raw materials mixed with sintered ore, and by combining it with high-temperature waste gas having favorable atmospheric components during activation. We have discovered a method for producing porous activated coke that is inexpensive and has excellent adsorption performance by selecting activation conditions. The present invention will be described in more detail as follows.

That is, the raw material for producing porous activated coke has a carbonization temperature of 400°C in order to suitably develop the pongee pore structure in the loading reaction.
~90,000 semi-formed coke is used. Carbonization temperature 40
At temperatures below 0°C, the pore structure is insufficiently developed and there are many residual substances, so activation takes a long time. Also, the carbonization temperature is 90
If it is more than 000, a product with excellent strength can be obtained, but the pongee hole structure has poor developability in the activation process. Therefore, a product with a carbonization temperature of 400 to 900oo is used, but in order to obtain a product with particularly excellent strength and quality, a carbonization temperature of 600 to 900oo is used.
Approximately 70,000 is preferable. As the raw coal for this semi-formed coke, in addition to highly viscous light blue coal for iron-making coke, any of lignite, anthracite, or a mixture of these coals may be used.

The next step is activation treatment, which involves converting this semi-formed coke to, for example, 0.
5-1.5 m/m, 1-2 m/m, 1.5-3 skin/skin,
The particles pulverized to a particle size range of about 2.5 to 5 m/m are placed in an activation furnace, and two-stage activation is performed using two types of inert gases containing oxygen and carbon dioxide, such as nitrogen gas and water vapor.

That is, first, heat treatment is performed using heated nitrogen gas of 70,000 or more containing 1% or less oxygen and 1% or more carbon dioxide for 10 to 2 hours to produce child heat and primary activation, and then steam is used for 0.5 to 2 hours. Porous activated coke with a large surface area can be obtained through short-time secondary activation. If the oxygen concentration in the heated nitrogen gas used in the primary activation is high, the yield will drop significantly due to oxidative combustion during competitive activation, and the quality will also be unfavorable, so it should be kept at 1% or less.

Furthermore, when the carbon dioxide concentration is 1% or more, the activation effect is sufficiently exhibited, and an increase in this content is rather preferable and makes the activation effect more suitable. The heating gas is, for example, 700 to 9
Approximately 500C is preferable for the development of the pongee hole structure, and below 70,000C the activation is slow, and above 95,000C the yield is poor and high quality products cannot be obtained. The development of the pongee pore structure is remarkable even with this primary activation alone, and a material that can be used as an adsorbent can be obtained even with this method, but the quality can be further improved by adding water vapor storage.

The product obtained by this two-step activation is far superior to that obtained by mere steam activation.

A feature of the present invention is that the number of active sites is increased by simultaneous activation of carbon dioxide activation and water vapor activation, and two-stage activation treatment, and a significant increase in pore volume and surface area is brought about.

Next, examples of the present invention will be given.

Example 1 Highly viscous bituminous coal-based semi-formed coke with a carbonization temperature of 600°C was pulverized to 1 to 2.5 m/m and placed in an activation furnace, and 0.5% oxygen and 5% carbon dioxide were added. The primary activation was carried out for 2 hours in a heated nitrogen gas atmosphere containing 80,000 ℃.

Then, 2 parts steam per 1 part weight of semi-formed coke per hour.
Through this, it was activated for 2 hours at 85,000. At the same time, only steam activation was performed directly under the same conditions without primary activation using heated nitrogen gas. Surface area and Japan Water Works Association standard KI1
Table 1 shows the iodine adsorption power measured according to the 3-1974 Powdered Activated Carbon Test Method for Water Supply. Table 1 Table 1 Example 2 Example 1 for lignite-based coke with a carbonization temperature of 60,000
Table 2 shows the performance of products activated in the same manner as .

Table 2 Example 3 The COD removal performance of the two-step activated coke obtained in Examples 1 and 2 and the commercially available coal-based activated carbon CAL (manufactured by Calgon) was investigated using actual wastewater.

The results are shown in Table 3.

The target wastewater used in the experiment was coke ammonium water treated with activated sludge and treated with iron salt coagulation and precipitation to have a COD of 70 PPM.

COD measurement is performed using acidic KMn0 according to JISK OI02.
Four methods were used. As shown in Table 3 and above, according to the method of the present invention, activated coke having an extremely large surface area and excellent adsorption performance can be obtained.

It can be effectively used to remove oil and organic COD from industrial wastewater and to remove air pollutants by sorption. Commercially available activated carbon is expensive because it is manufactured using carefully selected raw materials and requires a large amount of energy.

In the steel industry, heated nitrogen gas containing oxygen and carbon dioxide is also available, and semi-formed coke is also available at a relatively low price, so by utilizing both, it is possible to produce an inexpensive adsorbent with excellent performance.

Claims (1)

[Scope of Claims] 1. A method for producing porous activated coke, which comprises activating semi-formed coke with a carbonization temperature of 400 to 900° C. with a heated gas containing one or more of steam and carbon dioxide. 2 Semi-formed coke with a carbonization temperature of 400 to 900°C is heated to 700°C.
A method for producing porous activated coke, which comprises performing preheating and primary activation with heated gas at a temperature of 0.degree. C. or higher, and then performing secondary activation with heated gas containing water vapor.