JPH03246446A - Method for measuring grain size distribution of gypsum - Google Patents

Abstract

PURPOSE:To measure the grain size distribution of gypsum in a diluted gypsum slurry by the diffraction with a laser in a laser diffraction device as a light source by introducing the diluted gypsum slurry to the laser diffraction device. CONSTITUTION:A branch pipe 8 is mounted to the intermediate point of a conduit 7 for sending the gypsum slurry discharged from an oxidizing column 3 to a thickener 4 and a part of the gypsum slurry sent through the conduit 7 to the thickener 4 is introduced through the branch pipe 8 to a stirring chamber 9. The ethanol in a chamber 10 is added through a conduit into the gypsum slurry in the stirring chamber 9 and the gypsum slurry is sufficiently stirred and is diluted by the ethanol.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for automatically and accurately measuring the particle size distribution of gypsum produced from coke oven gas.

[Conventional technology]

Coke oven gas generated during carbonization of coal is sent to desulfurization equipment after recovering tar, light oil, ammonia, etc. as by-products from the gas, and the hydrogen sulfide (H2S) contained in the gas is sent to desulfurization equipment. ) are removed.

The waste liquid containing a large amount of sulfur produced by the desulfurization process in this desulfurization equipment is sent to a combustion furnace.

Then, in the combustion furnace, the sulfur content contained in the waste liquid is burned. The combustion exhaust gas generated at this time is sent to the gypsum manufacturing facility, where the sulfur dioxide gas (SO□) in the combustion exhaust gas and an amount of calcium hydroxide (Ca(0) Gypsum is produced by the reaction between 1) and 2).

FIG. 3 is a schematic process diagram of gypsum production in the gypsum production facility. As shown in Figure 3, combustion exhaust gas containing SO Then, make a calcium bisulfite slurry. Next, the calcium bisulfite slurry thus obtained was passed through tank 2,
It is sent to oxidation tower 3.

In this way, the calcium hydrogen sulfite slurry sent to the oxidation tower 3 reacts with the oxygen in the air blown into the tower from the lower part to become gypsum slurry. The gypsum slurry thus produced is sent to a gypsum separator 5 via a thickener 4.

Gypsum 6 is separated in a gypsum separator 5. In this way, plaster 6 is manufactured.

[Problem to be solved by the invention]

When producing gypsum as described above, it is necessary to control the production conditions so that the particle size distribution is at a predetermined value. When the average particle size of the product gypsum is smaller than a predetermined value, its commercial value decreases.

For this purpose, it is necessary to measure the particle size distribution of the product gypsum, but conventionally, particle size distribution was measured using a sieve, which required a lot of effort and was not possible to measure continuously, resulting in measurement accuracy. was also inferior.

Therefore, it is an object of the present invention to provide a method for continuously and automatically measuring the particle size distribution of gypsum produced from coke oven gas with high precision.

[Means to solve the problem]

This invention uses gypsum slurry produced in an oxidation tower,
A branch pipe is provided in the middle of the conduit that is sent from the oxidation tower to the equipment for the next process, and a part of the gypsum slurry is guided through the branch pipe to the stirring tank. The gypsum slurry is diluted by adding an ethanol solution of This method is characterized by measuring the particle size distribution of gypsum in gypsum slurry.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a process diagram showing one embodiment of the method of the present invention. As shown in FIG. 1, a branch pipe 8 is installed in the middle of a conduit 7 that sends the gypsum slurry discharged from the oxidation tower 3 to the thickener 4, and a part of the gypsum slurry sent to the thickener 4 through the conduit 7 is It is led to a stirring tank 9 through a branch pipe 8.

Next, ethanol in the tank 10 is added to the gypsum slurry in the stirring tank 9 through the conduit, and the slurry is sufficiently stirred to dilute the gypsum slurry with ethanol.

The amount of ethanol added to the gypsum slurry is preferably at a ratio of 100 parts of ethanol to 0.5 to 1.5 parts of the gypsum slurry.

The diluted gypsum slurry thus obtained.

The particle size distribution of gypsum in the diluted gypsum slurry is measured by diffraction using a laser as a light source.

FIG. 2 is a diagram showing the principle of the laser diffraction device 11.

As shown in FIG. 2, the laser diffraction device 11 includes a laser light source 12, a second lens 18, a fixed filter 14 having a slit 15, a rotating filter 16 having 13 windows 17, and a second lens 18. and photodetector 1
9 are arranged in line with each other, and a microprocessor 20 is connected to the photodetector 19.

The particle size distribution of the gypsum is determined by irradiating the flowing diluted gypsum slurry with a laser beam from the laser light source 12 and performing calculations according to a predetermined program based on the obtained diffraction image.

The removal of the gypsum slurry from the conduit 7 through the branch pipe 8 is performed intermittently at regular intervals by the valve 21, and all such operations are automatically performed according to a predetermined sequence.

In addition, in measuring the particle size distribution of gypsum using such a laser diffraction device 11, the gypsum slurry is as described above.
It is necessary to dilute with ethanol. Without dilution, too many gypsum particles will be present in the 2-gypsum slurry, reducing the accuracy of measuring the particle size distribution of 1-gypsum.

〔Effect of the invention〕

As described above, according to the present invention, the particle size distribution of gypsum produced from coke oven gas can be continuously and automatically measured with high accuracy, which is an industrially useful effect. brought about.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing one embodiment of the present invention, FIG. 2 is a principle diagram of a laser diffraction apparatus, and FIG. 3 is a schematic process diagram of gypsum production. In the drawing. l...absorption tower, 2...tank. 3. Oxidation tank, 4. Thickener 5. Gypsum separator, 6. Gypsum, 7. Conduit,
8. Branch pipe. 9. Stirring tank, 10. Tank, 11. Laser diffraction device, 12. Laser light source, 13. Runs,
14... fixed filter 15... slit,
16...Rotating filter 17...Window,
18...Second lens, 9 Photodetector. 0 Microflosser.

Claims (1)

[Claims] 1. A branch pipe is provided in the middle of the conduit that sends the gypsum slurry generated in the oxidation tower from the oxidation tower to the equipment for the next process,
A portion of the gypsum slurry is introduced into a stirring tank through the branch pipe, and then a predetermined amount of ethanol liquid is added to the gypsum slurry in the stirring tank and thoroughly stirred to dilute the gypsum slurry. Next, the diluted gypsum slurry is introduced into a laser diffraction device, and the particle size distribution of gypsum in the diluted gypsum slurry is measured by diffraction in the laser diffraction device using a laser as a light source. How to measure particle size distribution.