JPH0798979B2 - Method for controlling temperature of flash smelting furnace and temperature measuring device used therefor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a temperature control method for a flash smelting furnace for producing a mat, which is a smelting intermediate of the metal, from copper or nickel sulfide ore, and The present invention relates to a temperature measuring device used therefor.

[Problems to be Solved by Prior Art and Invention]

One of the smelting furnaces using sulfide concentrate as a raw material is a flash smelting furnace called a flash smelting furnace. As shown in FIG. 7, the conventional flash smelting furnace (copper flash smelting furnace) 1 has a reaction tower 3 provided with a concentrate burner 2 at the top and one end connected to the lower part of the reaction tower 3 and a side surface. The settler 6 is basically provided with the Karami outlet 4 and the river outlet 5, and the smoke exhaust passage 7 is connected to the other end of the settler 6. And the smelting process by this was as follows.

First, the powdered concentrate 8 is blown into the reaction tower 3 from the concentrate burner 2 together with the reaction gas 9 such as preheated air. In the reaction tower 3, sulfur and iron which are combustible components in the powdery concentrate 8 react with the reaction gas 9 and are stored in the settler 6 which is a hot water reservoir. In the settler 6, the melt is divided into a kawa 10 which is a mixture of Cu ₂ S and FeS and a karami 11 which contains 2FeO.SiO ₂ as a main component, depending on the difference in specific gravity. And Karami
11 is discharged from the Karami drain port 4 and introduced into the electric smelting furnace 12. On the other hand, the river 10 is extracted from the Karami extraction port 5 in accordance with the demand in the batch process of the converter, which is the next step.

Further, the high temperature exhaust gas 13 generated in the reaction tower 3 is discharged through the settler 6 and the flue gas duct 7, and is cooled by the boiler 14. The kalami that has entered the electric smelting furnace 12 is heated and held by the electric heat supplied by the electrode 15, and is mixed with the lump ore or flux that is inserted into the electric smelting furnace if necessary, and the copper content further settles on the bottom of the furnace. Only the kalami containing a slight amount of remaining copper is discharged from the outlet 16 to the outside of the furnace.

By the way, although an auxiliary fuel is used in the reaction tower 3 to make up for the lack of heat, the reaction heat of the raw material concentrate and the combustion heat of the auxiliary fuel make the inside of the reaction tower 3 a considerably high temperature atmosphere.
For this reason, if an excessive amount of auxiliary fuel is used, the heat load on the reaction tower 3 will increase, and the inner wall bricks of the reaction tower 3 will be severely melted. This brick melting is closely related to the heat load of the reaction tower 3, and when this heat load exceeds 350,000 cal / m ³ · h, brick melting becomes significant, so 250,000 cal / m ³ · h Must be:

On the other hand, in the operation of a flash smelting furnace in which the concentrate, the melt, the fuel, etc. are blown into the reaction tower 3 for melting, in order to effectively use the fuel and improve the efficiency of the reaction, the concentrate or the melt in the reaction tower 3 Is preferably completely melted, and for that purpose, it is necessary to raise the temperature inside the reaction tower 3 to a predetermined temperature or higher.

Therefore, it is desirable to control the temperature within a certain range by measuring the surface temperature of particles in the space inside the reaction tower 3 and adjusting the blowing amount of the auxiliary fuel.

However, it is technically very difficult to measure the surface temperature of the particles, and conventionally, the temperature of the river extracted from the river outlet 5 or the kelami extracted from the leather outlet 4 is measured, and this temperature is measured. Was used as a parameter to calculate the amount of heat and adjust the amount of auxiliary fuel injected.

However, the temperature of the river can be measured only when the river is removed from the outlet 5 of the smelting and smelting furnace 1 according to the operation of the converter, so that the temperature of the particles in the reaction tower 3 can be quickly responded to. There is a problem in that the error cannot be removed and the error tends to increase, and the temperature of the kelami can be measured only when it is intermittently pulled out from the larami extraction port 4 like the river, and there is a similar problem.

The present invention, in view of the above problems, enables quick and accurate temperature measurement that can be quickly responded to temperature changes in the reaction tower,
As a result, the amount of auxiliary fuel blown into the reaction tower can be adjusted accurately, so that the temperature inside the reaction tower is adjusted to a temperature at which the bricks in the reaction tower are not excessively heat-loaded and the concentrate and the melt are completely melted. An object of the present invention is to provide a controllable temperature control method for a flash smelting furnace and a temperature measuring device used therefor.

[Means and Actions for Solving Problems]

As a result of diligent research efforts, the present inventors have found that the temperature of the kawarami and the river near the kamiami layer accurately reflect the temperature in the reaction tower. In order to accurately grasp the temperature in the reaction tower and its change by measuring the temperature of, the precise temperature control was made possible.

That is, the temperature control method according to the present invention, a reaction tower provided with a concentrate burner at the top, a settler having one end connected to the lower portion of the reaction tower and provided with a side opening and a drainage port on the side, In a flash smelting furnace equipped with a flue gas outlet connected to the other end of the settler, the temperature of the kalami in the settler and / or the kawa near the kalami layer is measured, and the reaction tower according to the temperature is measured. The feature is that the amount of auxiliary fuel supplied to the inside is adjusted.

Further, in order to accurately measure the temperature, it is necessary to bring the thermometer to the measuring position quickly and accurately.

In order to realize that, the temperature measuring device according to the present invention
A cyclomotor with a chain wound around a rotating shaft, a thermometer hung at the free end of the chain and inserted into and removed from the settler of a flash smelting furnace, and the direction and speed of the cyclomotor can be controlled. An inverter that drives the motor, a rotary transducer that converts the rotation of the cyclomotor into a pulse signal and outputs the pulse signal, and a pulse signal from the rotary transducer is counted, and the cyclode is detected at the point where the number of pulses is a pre-registered number. It is characterized by comprising an external set counter that outputs an instruction signal to the inverter to stop the motor.

〔Example〕

Hereinafter, the present invention will be described in detail based on the illustrated embodiments by assigning the same reference numerals to the same members as those in the conventional example.

FIG. 1 is a schematic sectional view of a flash smelting furnace 1 configured to carry out an embodiment of the method of the present invention. An inspection hole 17 is provided on the top wall of the settler 6, from which a thermometer (consumable thermocouple) 18 of a temperature measuring device, which will be described in detail below, is inserted and lowered, and the central portion of the karami 11 is lowered. The temperature of the point B and / or the river 10 near the Karami layer 11 (for example, 100 mm lower part)
The temperature of the point C in the inside is measured. In addition, the temperature at the point A at the outlet of the reaction tower 3 is set as the temperature closest to the surface temperature of the particles in the reaction tower 3 among the measurable temperatures. A meter (consumable thermocouple) 20 is inserted for measurement.

Figure 2 shows the reaction tower 3 when operating at an ore throughput of 60 t / h.
It shows an example of the results of measuring the temperature of the fallout port, the temperature of the karami 11 at the center of the settler 6 and the temperature of the river 10 near the river 11 every 10 days. According to this, it is clear that the temperature of the karami 11 and the river 10 near the karami layer 11 accurately reflects the temperature of the outlet of the reaction tower 3 and thus the temperature of the particles in the reaction tower 3. Therefore, Karami 11 and Karami layer
By measuring the temperature of one or both of the temperatures of the river 10 in the vicinity of 11, it is possible to accurately grasp the temperature in the reaction tower 3 and its change, thereby controlling the amount of auxiliary fuel blown into the reaction tower 3. For example, extremely accurate temperature control is performed.

In order to adjust the auxiliary fuel, it is usually sufficient to measure the temperature of either the Karami 11 or the Kawa 10, but if unmelted material occurs in the furnace 1, the Kawa temperature will drop, and the Karami temperature and the Kawa temperature Since the difference becomes large, it is desirable to measure both the Karami temperature and the Kawa temperature in order to know the furnace condition.

FIG. 3 is a diagram showing an example of the temperature distribution in the vertical direction of the melt in the settler 6 when operating at an ore processing rate of 60 t / h. It can be seen that the lower the melt, the lower the temperature due to the influence of the furnace bottom, and that the temperature of the river 10 near the kalami layer 11 hardly changes up to about 200 mm below the lower surface of the kalami layer 11. Therefore, the temperature measurement position of the Kawa 10 is the lower surface 20 of the Karami layer 11.
It is desirable to be 0 mm below.

Further, there is a temperature difference of about 140 ° C. between the highest temperature Karami layer 11 and the portion immediately near the bottom of the furnace, but this temperature difference varies depending on the residence time of the river 10 and the furnace conditions. Therefore, the temperature of the river extracted from the river outlet as in the past becomes the average temperature of the rivers at these various temperatures, which is far from representative of the temperature in the reaction tower 3 and also the measured temperature. It also shows that the bulkiness becomes larger.

In addition, the horizontal measurement position of the temperature of the Karami 11 and the river 10 is
Any position of the settler 6 may be used as long as it is not affected by the side wall or the furnace bottom.

FIG. 4 shows an embodiment of a temperature measuring device for measuring the temperature of the leather 10 and the kelami 11 in the settler 6.

Reference numeral 21 is a cyclomotor in which a chain 22 is wound around a rotary shaft, and a holder 23 is provided at the free end (lower end) of the chain 22.
A thermometer 18 is attached via. 24 is an inverter that is connected to the cyclomotor 21 and drives the cyclomotor 21 so that the rotation direction and rotation speed can be controlled, and 25 is attached to the rotation shaft of the cyclomotor 21 to rotate the cyclomotor 21 by a predetermined number of pulse signals. Transducer to convert to and output, 26 is transducer 25
And a power source connected to the inverter 24, 27 is an external setter connected to the power source 26, 28 is an external set counter connected to the external setter 27 and capable of storing a plurality of count numbers, and these are control circuits. I am configuring. 29 is a recorder connected to the thermometer 18, and 30 is an indicator connected to the recorder 29.

Next, the operation of this embodiment will be described.

First, when the switch provided in the power supply 26 is turned on, the inverter 24 operates and the cyclomotor 1 rotates, and as a result, the chain 22 descends, the holder 23 and the thermometer 18 descend, and they are inserted into the furnace 1. . On the other hand, the rotation of the shaft of the cyclomotor 21 is converted into a predetermined number, for example, 1000 pulse signals per rotation by the rotation transducer 25, and the pulse signals are sent to the external set counter 28.

The external set counter 28 counts the received pulse signals and, when approaching the number of pulses registered in advance by the external setter 27 by the external setter 27, relays the power supply 26 and outputs an instruction signal to the inverter 24 to slow the rotation. And when the number of registered pulses is reached, the cyclomotor
It outputs a signal to stop the rotation of 21. By this signal, the cyclomotor 21 stops its rotation and brakes, thereby eliminating the blurring after the stop and ensuring the stop accuracy.

Although a plurality of stop positions can be set, in this embodiment, the stop positions are set so as to measure the temperatures at two points of the central part of the kalami layer 11 and the river 10 near the kalami layer 11. It is set.

Thus, according to this embodiment, it is possible to bring the thermometer 18 to the measuring position quickly and accurately.

The material of the holder 23 is 1300 ° C because it is inserted into the melt.
Any material can be used as long as it can be used in an oxidizing atmosphere to some extent, and SUS 304 is used in this embodiment. Moreover, since the working temperature of the thermometer 18 is 1200 to 1300 ° C, a thermocouple is suitable,
Particularly, the consumable thermocouple, which has high measurement accuracy at high temperature and does not require periodic inspection, is most suitable. In order to protect the thermometer 18, the shorter the residence time of the thermometer 18 in the flash smelting furnace 1, the better. Therefore, using the inverter 24, the descending speed is increased until the thermometer 18 is immersed in the molten metal, and the ascending / descending speed is decreased after the immersion to increase the stop accuracy, and the ascending speed is increased after the measurement. There is.

Further, in the present embodiment, the pulse signal is used for controlling the ascending / descending distance, but other than that, a limit switch, a micro switch, a photoelectric switch, an approach switch, an ultrasonic switch or the like can be used. However, these have a problem that the stopping accuracy is completely inferior to that of the present embodiment or is too expensive. Further, as an elevating device, it is conceivable to use an electric hoist or a mechanism for elevating a thermometer support portion screwed by rotating a screw, but any of them has difficulty in stopping accuracy.

Experimental Example 1 Performing calorific value calculation using the temperature of the river removed from the river as in the past, and adjusting the amount of auxiliary fuel blown into the reaction tower while operating at an ore processing rate of 60 t / h for 2 months. After that, the calorific value was calculated using the temperature of the river 100 mm directly below the Karami layer in the settler, and the amount of auxiliary fuel blown into the reaction tower was adjusted while the ore throughput of 60 t / h was adjusted to 5
I operated for a month. The monthly average value of the gas temperature in the reaction tower measured during this period is shown in FIG. During the test operation, there was no change in the viscosity of the kelami or the river, and no unmelted material was formed.

As is apparent from FIG. 5, the gas temperature in the three months using the method of the present invention is about 40 ° C. lower on average than the gas temperature in the first two months using the conventional method. This decrease in gas temperature indicates that excessive auxiliary fuel was blown in in the conventional method.

Experimental Example 2 Using the temperature measuring device shown in FIG. 4, the first stop point was set to 3640 mm below the reference point, the second stop point was set to 3840 mm below the reference point, and the stop time was set to 2 minutes. Stopping accuracy was measured. The results obtained are shown in the table below.

The first stop point corresponds to the Karami layer, and the error in the measured values is 6 mm at maximum. The second stopping point corresponds to the Kawa layer,
The maximum error of the measured value was 5 mm.

Since the thickness of the kalami layer is at least about 30 mm, it is clear that there is no problem in use.

Experimental Example 3 Using the temperature measuring device shown in FIG. 4, the rest time at the first stop point was set to 20 sec, and the rest time at the second stop point was set to 18 sec. The temperature and the river temperature were measured. The results are shown in FIG.

Reference numeral 31 is a measurement start time point, 32 is a time point when the thermometer enters the Karami layer, and 33 is a time point when the thermometer is stopped in the Karami layer. 34 is the time when the thermometer is lowered again after 20 seconds, and 35 is the time when the thermometer is stopped in the Kawa layer 100 mm below the Karami layer. 3
6 is the time when the thermometer was started to be lifted after standing still for 15 seconds, and 37 was the time when it was completely lifted.

As a result, the temperature of Karami is 1230 ℃, the temperature of Kawa is 1200 ℃.
Met.

〔The invention's effect〕

As described above, according to the temperature control method of the flash smelting furnace and the temperature measuring device used therefor according to the present invention, it is possible to quickly respond to the temperature change in the reaction tower and to perform accurate temperature measurement. The temperature of the auxiliary fuel in the reaction tower in the reaction tower can be controlled to a temperature at which the concentrate or the melt is completely melted without giving an excessive heat load to the brick of the reaction tower. Therefore, there is an advantage that the life of the brick can be extended and the amount of the auxiliary fuel blown into the reaction column can be greatly reduced because the average temperature does not decrease and the measured temperature does not vary.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a flash smelting furnace configured to carry out an embodiment of a temperature control method according to the present invention, and FIG. 2 is a reaction tower outlet temperature and a center of a settler in actual operation. The figure which shows an example of the result which measured the Karami temperature and the Kawa temperature of the part every 10 days, FIG. 3 is a figure which shows an example of the vertical temperature distribution of the molten metal in a settler, and FIG. 4 is the temperature by this invention. FIG. 6 is a schematic view of an embodiment of a measuring apparatus, FIG. 5 is a view showing a difference between monthly average values of gas temperatures in a reaction tower according to the conventional method and the method of the present invention, FIG.
The figure shows the result of measuring the temperatures of the kelami and the river in the settler using the temperature measuring device, and FIG. 7 is a schematic sectional view of a conventional flash smelting furnace. 1 ... Smelting and smelting furnace, 2 ... Concentration burner, 3 ... Reaction tower, 6 ... Settler, 7 ... Smoke exhaust, 10 ... Kawa, 11 ...
… Karami, 17, 19 …… Inspection hole, 18, 20 …… Thermometer, 21 ……
Cyclomotor, 22 …… chain, 23 …… holder,
24 ... Inverter, 25 ... Transducer, 26 ...
… Power supply, 27 …… External setter, 28 …… External set counter, 29 …… Recorder, 30 …… Indicator.

Claims (2)

[Claims] 1. A reaction tower provided with a concentrate burner at the top, a settler having one end connected to a lower part of the reaction tower and provided with a side opening and a drainage port, and another end of the settler. In a flash smelting furnace equipped with a flue gas outlet connected to, the temperature of the kalami in the settler and / or the river in the vicinity of the kalami layer is measured, and auxiliary to supply into the reaction tower according to the temperature. A temperature control method characterized in that the amount of fuel is adjusted. 2. A cyclomotor having a rotating shaft around which a chain is wound, a thermometer hung at the free end of the chain and inserted into and removed from a settler of a flash smelting furnace, and the cyclomotor is rotated in the direction of rotation. And an inverter that drives the rotation speed controllable, a rotation transducer that converts the rotation of the cyclomotor into a pulse signal and outputs the pulse signal, and the pulse signal from the rotation transducer is counted to obtain the number of pulses registered in advance. A temperature measuring device comprising an external set counter that outputs an instruction signal to the inverter so that the cyclomotor stops at a certain point.