JPH05164673A - Measuring method of carbon of powder sample and apparatus therefor - Google Patents

Abstract

PURPOSE:To speedily measure the amount of non-compound type carbon by one reaction container without stains caused by the adhering matter to a carbonic acid gas detector or corrosion by halogen gas. CONSTITUTION:A compound-type carbon and a non-compound type carbon are mixed in a powder sample A. After the powder sample A is set in a reaction container, as the reaction container is heated from outside, an inert gas is supplied to substitute the interior of the container. Thereafter, the powder sample A is heated to a predetermined temperature and the compound-type carbon is dissolved into a carbonic acid gas. The carbonic acid gas is discharged together with the inert gas. Then, the supply of the inert gas is stopped. While an oxygen gas is being supplied from the direction opposite to that of the inert gas, the powder sample A is heated to 1000-1300 deg.C to burn the non-compound type carbon. The resultant carbonic acid gas is introduced into a carbonic acid gas detector M which communicates with the side of the reaction container opposite to the supply side of the oxygen gas. The amount of the non-compound type carbon is measured by measuring the amount of the carbonic acid gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a non-combined powder sample containing uncombined carbon (powder coke, powder charcoal, etc.) and combined carbon (calcium carbonate, carbonate carbonate, sodium carbonate, etc.). The present invention relates to a method and apparatus for measuring the amount of carbon in the mold.

[0002]

The raw material of the Related Art sintered ore used in SeiTetsugyo In addition to iron ore, limestone (CaCO _3), carbonate Natoryumu (NaCO _3), carbonate Maguneshumu (MgCO ₃₎
It contains compounded carbon as a carbonate such as and non-combined carbon such as coke powder. The method of measuring the powder coke in this raw material, that is, the amount of non-combined carbon, is, for example, as described in Japanese Patent Publication No. 1-30108, the carbon dioxide gas of carbon monoxide / oxygen dioxide is burned in an oxygen stream. Then, there is a combustion measurement method in which the carbon dioxide gas is detected by a carbon dioxide gas detector using an infrared absorption method, a coulometric titration method, or the like, and the carbon content is measured from the temperature.

However, in the case of the powder sample in which the non-compounding carbon and the compounding carbon are mixed in this method, both carbons become carbon dioxide gas, and therefore both are measured, and only the non-compounding carbon is measured. Could not be measured. As a method for measuring the amount of non-combined carbon in such a mixed sample, as described in "Japan Analytical Chemistry Handbook" edited by the Japan Society for Analytical Chemistry (published on September 20, 1981) P145, Maruzen Co., Ltd. After adding phosphoric acid or hydrochloric acid to the powder sample in advance to decompose and dry the carbonate as the compound carbon and remove the compound carbon, the non-compound carbon that does not react with the phosphoric acid or hydrochloric acid is subjected to the combustion measurement. Some are measured by the method. After heating the carbonate of the powder sample in a reaction vessel (hereinafter referred to as a cylindrical furnace) in an inert gas atmosphere to decompose it into carbon dioxide and release it, the non-combined carbon is measured by the combustion measurement method. There is something.

[0004]

However, the above-mentioned method of decomposing carbonate with phosphoric acid or hydrochloric acid is troublesome because of the handling of phosphoric acid or hydrochloric acid and the drying of phosphoric acid or hydrochloric acid after the treatment, and at the same time, in an oxygen atmosphere. At the time of burning the uncombined carbon, the residual phosphoric acid or hydrochloric acid evaporates, and flows into the carbon dioxide gas detector together with the carbon dioxide gas generated by the combustion of the uncombined carbon. It was sometimes corroded.

Further, in the method of decomposing carbonate in the above-mentioned inert gas atmosphere, since the gas body in the cylindrical furnace is released to the outside through the carbon dioxide gas detector, it is volatilized to the powder sample. In the case where the amount of volatile components is present, it is attached to the carbon dioxide gas detector due to its volatile components, and when fluorine and chlorine are mixed in the sample, these become halogen gas. Since the detector corrodes, the step of decomposing carbonate in an inert gas atmosphere and the step of burning uncombined carbon in an oxygen atmosphere must be performed in separate cylindrical furnaces, which is complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is free from stains caused by deposits on a carbon dioxide gas detector and corrosion caused by halogen gas. It is possible to rapidly measure the amount of non-combined carbon with one tubular furnace. The present invention has been made to solve the above problems, and means 1 thereof is provided.
After charging a powder sample in which compounded carbon and non-compounded carbon coexist in the reaction vessel and supplying an inert gas while externally heating the reaction vessel to replace the inside of the vessel with the gas , The powder sample is heated to a predetermined temperature to decompose the compounded carbon into carbon dioxide gas and exhausted together with the inert gas, after which the supply of the inert gas is stopped and the reverse of the inert gas is applied. The powder sample from 1000 to 13 while supplying oxygen gas from the direction.
The non-combined carbon is burned by heating to 00 ° C., and the carbon dioxide gas generated by this is introduced into a carbon gas detector connected to the anti-oxygen gas supply side of the cylindrical furnace and the amount thereof is measured. This is a method for measuring the amount of non-combined carbon.

The means 2 has a charging port on one side, a carbon dioxide gas detector is connected to the other side, and has a heater in the middle part. In the reaction container, there is no connection between the charging port of the reaction container and the heating device. A supply pipe for supplying an active gas is communicatively connected, and a supply pipe for supplying an oxygen gas is communicatively connected between a communication connection side of a carbon dioxide detector and a heater.

[0008]

The operation of the present invention will be described with reference to FIG. First, a charging port 1 provided on one side of a cylindrical furnace 1 as a reaction container.
From a, in the state where the powder sample A in which the compound carbon and the non-compound carbon are mixed is charged therein, the inert gas is supplied to the supply pipe 7
From the sample inlet 1a to form an inert gas flow in the direction of arrow B, and the cylindrical furnace 1
The inside is replaced with an inert gas.

In this state, the temperature in the cylindrical furnace 1 is raised to a predetermined temperature by a heater (hereinafter referred to as a heater) H1 to decompose the carbonate of the compound carbon of the powder sample A into carbon dioxide gas. Together with the volatile components such as oil adhering to the powder sample A,
Fluorine and chlorine mixed in the powder sample A are separated by a halogen gas, and the carbon dioxide gas, volatile matter, and halogen gas together with the inert gas are exhausted to the outside from the sample inlet 1a.

By performing this treatment for a predetermined time, the compound carbon of the powder sample A is removed and harmful substances such as oil, fluorine and chlorine (substances that pollute the carbon dioxide gas detector or oxidize it to cause harm). Remove. At this time, it is preferable that the treatment temperature is higher because the treatment time can be shortened.
At 900 ° C. or higher, the oxygen contained in the oxide in the powder sample A reacts with the uncombined oxygen to decompose,
The heating upper limit temperature is preferably about 850 ° C.

The lower limit temperature for heating does not significantly extend the heat treatment time, and is a temperature at which the compound carbon in the powder sample A is decomposed, for example, the powder sample A is limestone (CaCO ₃ ) , Iron ore, serpentine, slaked lime, etc., 700 ° C (the temperature at which ordinary carbonate of limestone decomposes is 850 ° C, but the iron ore, serpentine, slaked lime etc. When containing, the catalytic action of the iron ore,
Due to the melting point lowering action due to the mixing, the temperature at which the carbonate of limestone decomposes decreases, and the decomposition time also becomes about 8 minutes. ) Depending on the raw material contained in the powder sample A.

Next, the sample inlet 1a of the cylindrical furnace 1 is sealed and changed to the inert gas, and oxygen gas is supplied to the supply pipe 8.
The powder sample A is heated to 1000 to 1300 ° C. while being supplied to the carbon dioxide gas detector M and forming an oxygen gas flow in the direction of arrow C, which is the opposite direction to the inert gas flow. As a result, the non-combined carbon of the powder sample A is burned and decomposed into carbon dioxide gas, and the carbon dioxide gas detector M together with the oxygen gas.
Flow into.

By doing so, the carbon dioxide gas detector M is prevented from introducing volatile components such as oil and halogen gas into the carbon dioxide gas detector M, and the carbon dioxide gas detector M is eliminated.
Since the generation of stains and oxidation in the interior is almost eliminated, it is possible to perform accurate measurement for a long period of time, and it is possible to significantly extend the life.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1 is a cylindrical furnace, 1a is a charging port provided on one side of the cylindrical furnace 1, 3 is a sample charging port lid that is openably and closably provided in the charging port 1a via a seal packing 2, H1 and H2. Is a heater arranged on the outer periphery of the middle part of the cylindrical furnace 1, 4 is a porcelain sample boat charged with the powder sample A, 5 is a cylindrical combustion gas introduction pipe 6 connected to the carbon dioxide detector M Combustion gas introduction pipe fitting connected to the other side of the furnace 1, and 7 connected to the other side of the cylindrical furnace 1 (connection side of the carbon dioxide gas detector M) to supply nitrogen gas as an inert gas. A gas supply pipe, 8 is an oxygen gas supply pipe connected to one side (the charging port 1a side) of the cylindrical furnace 1 to supply oxygen gas, V1 is a valve provided in the nitrogen gas supply pipe 7, and V2 is oxygen gas A valve provided in the supply pipe 8,
T1 and T2 are thermometers provided on the heaters H1 and H2.

Next, the case of measuring the amount of coke in the sintering raw material will be described. First, heating is started while observing the temperature measurement value of the thermometer T1 so that the cylindrical furnace 1 is maintained at 750 ° C. by the heater H1, and further the cylindrical furnace 1 is maintained at 1300 ° C. by the heater H2. Then, heating is started while observing the temperature measurement value of the thermometer T2. Next, the valve V1
Is opened to supply nitrogen gas into the cylindrical furnace 1 from the nitrogen gas supply pipe 7 and exhaust the nitrogen gas from the charging port 1a to form a nitrogen gas flow in the direction of the arrow B. The air is replaced with nitrogen gas.

In this way, the 750 ° C. range and the 1300 ° C. range are formed in the longitudinal direction of the cylindrical furnace 1. In this state, the sample inlet cover 3 is opened (position indicated by the dotted line), and the sample boat 4 containing a predetermined amount of sintering raw material sample (hereinafter simply referred to as powder sample) A is inserted into the heater H1 position of the cylindrical furnace 1. Charge P1. At this time, the sample loading lid 3 is set at the position indicated by the alternate long and short dash line so that a slight gap is generated between the sample loading lid 3 and the packing 2.

As a result, the powder sample A is heated at 750 ° C. for 8 minutes in a nitrogen gas atmosphere, and the compound carbon as a carbonate such as limestone, sodium carbonate, magnesium carbonate, etc. in the powder sample A is carbon dioxide gas. At the same time, the volatile components such as oil are vaporized, fluorine and chlorine are separated as a halogen gas, and the halogen gas is discharged to the outside from the sample inlet 1a together with the nitrogen gas. Then, when the powder sample A is heated in the cylindrical furnace 1 for 8 minutes, the valve V1 is closed and the supply of the nitrogen gas from the nitrogen gas supply pipe 7 into the cylindrical furnace 1 is stopped. The preliminary processing of A is completed.

Next, the sample inlet cover 3 is opened again, the sample boat 4 is pushed into the heater H2 position P2, and then the sample inlet cover 3 is closed and hermetically closed. Then, by opening the valve V ₂ of the oxygen gas supply pipe 8 and supplying oxygen gas into the cylindrical furnace 1, the non-combined carbon of the powder sample A heated to 1300 ° C. is burned to generate carbon dioxide gas. Becomes By sequentially introducing the carbon dioxide gas together with the oxygen gas into the carbon dioxide detector M through the combustion gas introducing pipe 6, the oxygen gas flows in the direction of arrow C. Thus, when the carbon dioxide gas is no longer generated, the valve V2 is closed and the oxygen gas supply from the oxygen gas supply pipe 8 into the cylindrical furnace 1 is stopped.

The amount of carbon dioxide gas introduced in this way is measured by the carbon dioxide gas detector M, and the ratio of uncombined carbon K (%) in the sample is calculated from the measured amount of carbon dioxide gas G (ml) by the following formula. .. K = {(G / 22400 (ml / mol)) × 12 (g / mol) × 100} / M where M is the sample weight (g)

FIG. 2 shows another embodiment. In the above embodiment, two heaters H are provided in the cylindrical furnace 1.
1 and H2 are installed, and the cylindrical furnace 1 has 750 ° C range and 1300 ° C.
Although the zones are formed at different places, in this example, the heater H is only a single group, and the current flowing through the heater H is changed to heat at 750 ° C. and 1300 ° C. In this case, it is not necessary to move the sample boat 4 in the cylindrical furnace 1, which is preferable.

[0021]

EFFECT OF THE INVENTION According to the present invention, a carbon dioxide gas detector for measuring the amount of uncombined carbon in a powder sample in which uncombined carbon and compound carbon are mixed is stable with good measurement accuracy over a long period of time. In addition to being able to maintain the temperature, it is possible to prevent oxidation of the carbon dioxide gas detector, so that it is possible to greatly extend the life of the carbon dioxide detector.

[Brief description of drawings]

FIG. 1 is a simplified side sectional view showing an embodiment of the present invention.

FIG. 2 is a simplified side sectional view showing another embodiment of the present invention.

[Explanation of reference symbols] 1 tubular furnace 2 packing 3 sample inlet lid 4 sample boat 5 combustion gas introduction pipe fitting 6 combustion gas introduction pipe 7 nitrogen gas supply pipe 8 oxygen gas supply pipe 1a sample inlet M carbon dioxide detector A powder sample H1 heater H2 heater T1 thermometer T2 thermometer V1 valve V2 valve P1 heater H1 position P2 heater H2 position

Claims (2)

[Claims] 1. A reaction vessel is charged with a powder sample in which compounded carbon and non-compounded carbon are mixed, and an inert gas is supplied while the reaction vessel is externally heated to supply the gas in the vessel. After the replacement, the powder sample is heated to a predetermined temperature to decompose the compound carbon into carbon dioxide gas and exhausted together with the inert gas, and thereafter, the supply of the inert gas is stopped and the inert gas is removed. While supplying oxygen gas from the opposite direction to 10
The non-combined carbon is burned by heating to 00 to 1300 ° C., and the carbon dioxide gas generated by this is introduced into a carbon dioxide detector connected to the anti-oxygen gas supply side of the reaction vessel, and the amount is measured. The method for measuring carbon in a powder sample, comprising: 2. A reaction vessel having a charging port on one side, a carbon dioxide gas detector on the other side, and a heater in the middle, and an inert gas between the charging port of the reaction vessel and the heating device. A carbon measuring device for a powder sample, characterized in that a supply pipe for supplying gas is connected in communication, and a supply pipe for supplying oxygen gas is connected in communication between a communication connection side of a carbon dioxide detector and a heater.