JP2000328150A - Operating method of self-fluxing furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operating method to efficiently perform the reaction inside the reaction tower of a self-fluxing furnace. SOLUTION: In the operating method of the self-fluxing furnace, a probe for measuring the temperature having a consumable thermostat mounted thereon is inserted into measurement holes 4-7 provided on a side wall of a reaction tower, the temperature distribution of dropping objects in the reaction tower is measured by changing the insertion depth at equal intervals, the temperature distribution is set to be a reference to judge the situation of the reaction in the reaction tower, and the reaction in the reaction tower is stabilized by adjusting the operating condition on the basis of the result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating an auto-kump type flash furnace used for smelting non-ferrous metals.

[0002]

2. Description of the Related Art Auto-kump type flash smelting furnace is a kind of smelting furnace used for smelting non-ferrous metals. In this flash smelting furnace, a dry raw material of fine powder obtained by adding silicate ore as a solvent to a sulfide concentrate is supplied from a concentrate burner installed at the top of a cylindrical reaction tower together with auxiliary fuel and oxygen-enriched air into the reaction tower. To cause an oxidative combustion reaction in the gas phase. As a product of this oxidation reaction, a mat in which valuable metals such as copper are concentrated, and a slag mainly composed of iron and silica are obtained as a melt,
Stay in Settler.

[0003] The oxidation reaction is completed within a very short time when the dry raw material falls in the reaction tower, but averaging the degree of oxidation of the reactant as much as possible is an important control point in the operation of the flash smelting furnace. is there. However, in the reaction tower, the dry raw material may be locally supplied in excess to the oxygen-enriched air, or vice versa. In the former case, the oxidation is insufficient and the undissolved matter accumulates on the surface of the molten metal or scatters as smoke, and oxidizes and burns in the waste heat recovery boiler to increase the gas temperature, adhere to the water pipes, and heat The exchange rate may be reduced. In the latter case,
Iron in the raw material is peroxidized to cause deterioration of slag properties, hindering separation of the product mat and slag, and generating in-furnace deposits around the smoke outlet. These cause a loss of valuable metal in the slag, a mat, and a blockage of the slag tap hole, and also cause a change in the temperature of the molten metal, the grade of valuable metal in the mat, and adversely affect the operation to the post-process.

Further, the solid-gas ratio between the raw material and the oxygen-enriched air increases as the throughput of the flash smelting furnace increases, so that it becomes more difficult to uniformly disperse the fine powder raw material in the reaction air. Therefore, improving the mixing and dispersibility of the raw material and the reaction air and averaging the degree of oxidation of the reactants as much as possible not only stabilizes the operation of the flash smelting smelting furnace, but also increases the throughput to a single furnace. Is an extremely important control point in increasing the productivity and improving the productivity.

In order to estimate the reaction state in the reaction tower, a probe is inserted through a measurement hole provided in the side wall, and the temperature and oxygen potential of the falling object on the central axis of the reaction tower are measured.
Alternatively, a method of sampling a falling object is already widely practiced. However, it is dangerous to consider only the central axis of the furnace located directly below the concentrate burner that supplies the raw material and supplies the reaction air as the representative point of the entire furnace, and erroneously evaluates the reaction situation in the reaction tower. There was a concern that would give.

[0006]

Therefore, it has been necessary to consider accurately measuring the temperature distribution in the reaction tower. The present inventors have studied a method of measuring the temperature distribution of a falling object in a reaction tower and using the data for efficient operation as a criterion for determining the reaction state in the reaction tower. In other words, when peroxidation occurs, the oxidative combustion reaction proceeds excessively, so that the temperature of the falling object in the reaction tower increases, and conversely, if the oxidizing combustion reaction is insufficient, the temperature decreases. This is a method of estimating the distribution of the degree of oxidation by measuring the temperature distribution. In addition, in the present invention, the temperature distribution of the falling object in the reaction tower is periodically measured at a rate of at least once a day, and the daily reaction state is grasped to obtain a data on a method for responding to a change. So that the non-uniform state can be quickly resolved.

[0007]

That is, the present invention provides (1) a method of inserting a temperature measuring probe equipped with a consumable thermocouple from a measuring hole provided in a side wall of a reaction tower, and changing an insertion depth at an equal interval. By measuring the temperature distribution of the falling objects in the reaction tower,
The temperature distribution is used as a reference for judging the state of the reaction in the reaction tower,
A method for operating a flash smelting furnace, comprising stabilizing a reaction in a reaction tower by adjusting operating conditions according to the results.

[0008] (2) The temperature distribution in the reaction tower
The method according to the above (1), which is performed from the direction. (3) The above-mentioned (1), wherein the measurement is performed while automatically moving the measurement point on the diameter line of the reaction tower by a mobile temperature measuring device having a probe equipped with a consumable thermocouple at the tip.
The described method. It is.

Hereinafter, the present invention will be described in detail. FIG. 1 is a side view of an auto-kump flash furnace, and FIG. 2 is a plan view. One concentrate burner (20) was installed at the top center.
Inspection holes are installed at a total of 10 places on the side wall of the 2m x 6m height reaction tower with different heights and positions. The temperature distribution is measured at a level of about 4.5 m below the top (the arrow in the reaction tower in FIG. 1) and is measured from four inspection holes with an inner diameter of 100 mm, which are in a positional relationship as shown in FIG. These are A,
Called B, C and D holes. Incidentally, even if there are four or more inspection holes, it is not excluded from the present invention.

A dry raw material and oxygen-enriched air are blown into the concentrate burner (20), and fall while reacting in the reaction tower (1). About 0.5-0.7 to reach the position about 4.5m below
Although the time of seconds elapses, as a result of various investigations, it can be estimated that the reaction is completed at this position. The measurement point is not limited to the above-mentioned position, but is preferably a position where the reaction is almost completed.

The temperature is measured by attaching a consumable thermocouple (10) to the tip of the temperature measuring probe shown in FIG. 3 and inserting it into the reaction tower through each inspection hole (4-7). 15-25 after insertion
The temperature of the reaction product held in the reaction tower for 2 seconds and dropped onto the consumable thermocouple (10) is measured. As for the temperature, the signal from the consumable thermocouple (10) is chart-recorded (12).
Output to and record. At this time, for each inspection hole, the position of the tip of the consumable thermocouple (10) was set at 2.5m → 2m from the center of the reaction tower →
・ Temperature is measured at 50cm intervals such as 0m. The side fixed position may be any measurement point at which the following furnace temperature distribution can be accurately grasped. The measurement position is marked on the rear end side of the probe (9) in advance by calculating the length from the outer surface of the inspection hole furnace to the measurement point. After marking, the probe is inserted for one measurement point, held for 15 to 25 seconds, and the probe is removed. The temperature is measured and the consumable thermocouple is replaced. By performing the above measurement, a temperature distribution curve as shown in FIG. 4 is created.

Based on the temperature distribution curve, the presence or absence of a non-uniform reaction is estimated, the results of inspections at various locations are comprehensively determined, measures such as changes in operating conditions are taken, and a favorable reaction state is maintained. As a result, stable operations will be continued without reducing the raw material throughput. The above temperature measurement can be performed manually using a temperature probe as shown in FIG. 3, and FIG. 5 shows a temperature measuring device capable of performing this mechanically.

The lance (18) has a double pipe structure, and is cooled by flowing compressed air or compressed nitrogen from the inner pipe to the outer pipe. A holder (20) is installed at the tip of the lance (18), and a consumable thermocouple (10) is attached thereto. The lance (18) is supported by a support roller (19), and moves back and forth on a rail by a motorized driving carriage (15) at the rear of the lance. A chain (18) is laid on the rail, and a pinion gear rotates on the chain in conjunction with the movement of the drive cart. The number of rotations of the pinion is detected by an absocoder (16) on the driving bogie, converted into a moving distance, and moved according to a moving distance set by a variable limit. At this time, in order to minimize the time of exposure to the high temperature inside the furnace, move the measurement point from the fixed point in the furnace set by the variable limit and move the furnace from the measurement point after measurement for 15 to 25 seconds. High speed (30
５０50 m / min).

[0014]

EXAMPLE As a result of examining the cause of deterioration of the temperature distribution in the reaction furnace of the flash smelting furnace, it was found that the raw material had a bias at the time of charging, and during the furnace repair period, the raw material of the concentrate burner (20) was The charging part was modified to correct the drift when charging the raw materials. FIG. 4 shows the temperature distribution measured after the remodeling. This temperature measurement position is indicated by the arrow in the reaction tower (1) shown in FIG. At this time, the operating conditions were 140 t / h of raw material charge and 3
69 Nm ³ / min, the target copper grade in the mat is 63%, which is almost the same as the case of FIG. 6, but the temperature distribution is well-balanced between the left and right. . During this period, the furnace condition was relatively stable, and the copper loss in the slag was 0.60%.
Approximately 0.2% less than the case of FIG. 6 shown in the comparative example.

Thereafter, the temperature distribution in the reaction tower was used as one index of the reaction state. As a result, it is now possible to maintain stable operation while raising the target matte copper grade to 65%, increasing the raw material charge to 160t / h and increasing the processing capacity by about 14%.

[0016]

Comparative Example One comparative example will be described below in detail. FIG. 6 shows a representative example of the temperature distribution measurement results. This temperature measurement position is also indicated by the arrow in the reaction tower (1) in FIG. The operating conditions at this time were a raw material charging amount of 140 t / h, a total air blowing amount of 374 Nm ³ / min, and a target matte copper grade of 63%. As shown in FIG. 6, the temperature on the side of the hole A is about 1350 ° C. to 1400 ° C.
On the C hole side, the point 1 m to 2 m from the furnace center is 1200 ° C. or less, which indicates that the temperature distribution is poorly balanced. At this point, the furnace condition was unstable, and the copper loss in the slag, which was normally 0.65 to 0.70%, was 0.82%.
And worse.

[0017]

According to the method of the present invention, the reaction condition in the reaction tower can be accurately and easily evaluated, and the operating conditions can be quickly adjusted based on the evaluation result. This not only allows stable operation to continue,
It is possible to accurately respond to changes in operating conditions due to increased processing of raw materials. In addition, when a manual temperature measurement device was introduced and the measurement was performed manually, it took 30 minutes to 1 hour for five persons to measure in about 20 minutes for one operator of the apparatus.

[0018]

[Brief description of the drawings]

FIG. 1 is a side view of a flash smelting furnace.

FIG. 2 is a plan view of a flash smelting furnace.

FIG. 3 Probe for temperature measurement

FIG. 4 shows an example of a temperature distribution curve of the reactor of the present invention.

FIG. 5 is a temperature distribution measuring device for a reactor.

FIG. 6 shows a temperature distribution curve of the embodiment.

[Explanation of symbols]

 Reaction tower Raw material loading port Raw material loading port A hole B hole C hole D hole 8 Compensating conductor probe Consumable thermocouple Sub-sleeve Chart recorder Cooling air outlet Cooling air inlet Driving trolley Absocoder Chain lance Support roller 20 Concentrate burner

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K001 AA09 BA06 DA01 EA03 EA04 GA04 GB11 4K056 AA02 BA01 BB01 CA04 CA07 FA12

Claims (3)

[Claims] The temperature distribution of a falling object in a reaction tower is changed by inserting a temperature measurement probe equipped with a consumable thermocouple through a measurement hole provided in a side wall of the reaction tower and changing the insertion depth at equal intervals. And operating the temperature distribution as a reference for judging the state of the reaction in the reaction tower, and adjusting the operation conditions based on the result, thereby stabilizing the reaction in the reaction tower. . 2. The method according to claim 1, wherein the temperature distribution in the reaction column is measured from two orthogonal directions. 3. The method according to claim 1, wherein the measurement is performed while automatically moving the measurement point on the diameter column of the reaction tower by a mobile temperature measuring device having a probe having a consumable thermocouple attached to the tip. .