JPS5931793A - Preparation of nitrohumic acid - Google Patents

Abstract

PURPOSE:To prepare the titled compound having uniform and stable quality even from a mixture of a variety of raw materials, in high yield, with shortened reaction period with nitric acid, by controlling the water-content of a low- carbon coal such as lignite, brown coal, etc. to a specific level, and reacting with nitric acid. CONSTITUTION:Nitrohumic acid is prepared by reacting low-carbon coal such as lignite, brown coal, etc. with nitric acid. In the above process, the powdered low- carbon coal is fed from the stock tank 2 to an end of the moisture-controlling pug mill 1, and at the same time, water is supplied from the water tank 3 to attain the water-content of 30-40% according to the water-content of the original coal. The moisture-controlled coal is fed through the chuter 5 to one end of the reactor pug mill 6, dilute nitric acid is poured from the nitric acid tank 7 to the mill, the paddle 8 is rotated by conventional method to effect the stirring, reaction and transfer of the mixture of the low-carbon coal and nitric acid. The objective compound can be obtained by discharging the reaction product from the other end of the reactor pug mill 6 to the belt conveyor 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing nitrofumic acid, and an object of the present invention is to provide a method for producing nitrofumic acid with high quality and less variation.

Nitrohumic acid is produced by adding dilute nitric acid to seven or more types of young coal, such as lignite and brown coal, using a horizontal continuous reaction apparatus such as a bag mill.

However, the reaction between the raw material young coal and nitric acid is a solid-liquid reaction and the reaction rate is slow, and the reaction time and yield vary depending on the type of young coal, making it difficult to produce nitrofumic acid of a constant quality. is difficult.

As shown in Table 1, when the moisture content of young coal is 30-40%, the reaction success rate is high, and when the moisture content is 30% or less, the reaction success rate decreases.

Table 1 However, the moisture content of young coking coal varies depending on the type, production area, etc.
There is variation in the range of -5θ%. Also, initially 3O-l
Even if the raw material has a moisture content of 10%, the moisture content often decreases to 30% or less after being stored for 3 months. Moreover, in our country, the production of young coal extracted from mines is small, so in industrial production it is necessary to use a mixture of two or more types. The reaction rate tends to vary, the amount of unreacted substances increases, the reaction time becomes longer, and the yield is not always sufficient.

Furthermore, in Table 1, the reaction time required for the reaction completion rate to reach approximately qθ% was determined using the same young coal.

As is clear from Table 1, if the moisture content of the raw material is 30% or less, the added nitric acid will react in a short period of time, resulting in a decrease in the production rate of nitrofumic acid, making it impossible to achieve the purpose.

(3) By adopting the configuration described in the claims, the present inventors were able to obtain a method capable of stably producing nitrofumic acid of a constant quality in a high yield and in a constant time.

The drawings show an example of an apparatus used to carry out the present invention. Next, the present invention will be explained based on the drawings. A raw material storage tank 2 and a water tank 3 are attached to one side of a bag mill 1 for humidity control, and the storage tank 1 stores young coal pulverized to 32 meshes.

The crushed young coal is supplied from below the storage tank 1 to one end of the bag mill 1, and water is supplied from the water tank 3 so that the moisture content of the young coal becomes 30-10% depending on the moisture content of the young coal. .

Paddle 4 installed inside bag mill 1 at the same time
is rotated to transfer the crushed young coal to the other end of the bag mill 1 while stirring it.

In the above, when the moisture content of young coal reaches 11.6% or more (4
) This is not preferable because the nitric acid concentration during nitric acid oxidation is reduced and the residence time in the bag mill 1 is shortened due to the fluidity being too good, which reduces the reaction completion rate.

Furthermore, when the moisture content of the young coal is 1IO% or more, it is of course possible to adjust the moisture content by appropriately mixing young coal with low moisture content without supplying water into the bag mill 1. Incidentally, the humidity of young coal does not need to be controlled using a bag mill as shown in the illustrated example, and any type of apparatus may be used.

After adjusting the moisture content of the young coal as described above, the shooter
At the same time, a predetermined amount of dilute nitric acid is injected from the nitric acid tank 7 installed on the same side as the end of the reaction bag mill 6 where the shooter 5 is installed. Thereafter, the paddle 8 installed inside the reaction bag mill 6 is rotated in accordance with a conventional method to stir and react the young coal, which is then transferred and supplied from the other end of the reaction bag mill 6 to the belt conveyor 9.

Table 2 uses the equipment shown in the figure and the same raw materials as in Table 1 above, and then the sample is delivered -AL? about 35-10% moisture
After stirring and mixing in a humidity conditioning bag mill 1 for /S minutes, 11
．． This figure shows the case where 70 parts of S% nitric acid (anhydrous base weight) was simultaneously added to the reaction bag mill 6 and reacted.

From the results in Table 2, even if the original raw material contains less than 30% water, the reaction rate can be increased by adding water in advance to adjust the raw material moisture to 30%-110%. y can be a constant value.

As described above, in the present invention, before reacting young carbon with nitric acid,
By adjusting the moisture content of young coal to 30-40% in advance, the reaction time between young coal and nitric acid can be shortened.
Furthermore, the reaction rate of young coal and nitric acid can be maintained at a high and constant value, and 2L-lohmic acid of stable quality with less unreacted substances can be produced.

Example The young coal shown in Table 3 was pulverized to 32 meshes, and the moisture content was 3.
Add water to 5% and stir and mix for 75 minutes.

Table 3 Next, feed the raw materials (1) and (7) (2) whose moisture content was adjusted to 3S% as described above to a reaction bag mill with width/m, height/m, and length at a rate of /, gt/hour. At the same time, 15% dilute nitric acid was supplied at a rate of 7 t/hour, and the mixture was stirred and mixed for ZS minutes to obtain the products shown in Table 9.

Group table

[Brief explanation of the drawing]

The drawings show an example of the apparatus used to carry out the invention. 1... Humidity control bag mill, 2... Raw material storage tank, 3...
・Water tank, 4, 8...paddle, 5...shooter
56... Reaction bag mill, γ... Nitric acid tank. Patent applicant Rikichi Ichikawa (8) Agent of Japan Heavy and Chemical Industry Co., Ltd.

Claims (1)

[Claims] When producing nitrofumic acid by reacting young coal such as lignite or brown coal with nitric acid, the water content of the young coal is reduced in advance to 30°
%, and then reacting with nitric acid.