JP3367155B2 - How to adjust dry mine supply - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying raw materials to a smelting furnace used in a non-ferrous metal smelting furnace.

[0002]

2. Description of the Related Art Non-ferrous metal smelting methods using sulfide concentrates include a self-smelting method and a molten pool smelting method. The flash smelting method involves blowing powdery smelting raw materials such as sulfide concentrate, flux, and smoke ash and a reaction gas into the reaction tower from a concentrate burner provided at the top of the reaction tower of the flash smelting furnace. In addition, the molten metal refining method attempts to concentrate valuable metal as a kawa and separate other components as a kami by blowing the powdery raw material and the reaction gas into the molten metal stored in the furnace. Is.

By the way, when a large amount of this sulfide concentrate is stored in a dry state, iron sulfide and the like present in the sulfide concentrate spontaneously combust and a sulfide concentrate (hereinafter simply referred to as "concentrate") is produced. Risk of burning. The content of iron sulfide, etc. in the concentrate, as well as copper, sulfur, etc., differs depending on the place of production of the concentrate, that is, the so-called brand. For this reason, in order to prevent the natural combustion of the concentrate, it is common to store the minerals in a storage area in a damp state so as to be below a certain height and sorted by brand.

In order to supply the concentrate thus stored to the flash smelting furnace and process it efficiently and with high productivity, concentrates of various brands are blended before supply with copper and sulfur. It is necessary to adjust the quality with the kalamy component such as silicic acid and dry. For this reason, after providing a plurality of storage bins and using a belt conveyor from the storage field to supply concentrates and flux components such as silicate ore to the predetermined storage bins for storage, or While supplying to the storage bins, concentrates of each brand are cut out from the bottom of the storage bin at a specified ratio for each brand and supplied to the drying equipment. Then, the mixture of the prepared concentrate or silicate ore (hereinafter simply referred to as "dry ore") obtained by drying is provisionally placed in a relatively small storage bottle (hereinafter referred to as "relay bottle"). It is stored and continuously supplied from the relay bottle to the flash furnace.

In the flash smelting furnace, dry ore cut from a lower part of a relay bottle by a conveyor is supplied to a concentrate burner provided at the top of the reaction tower from the end of the conveyor, and the free fall in the concentrate chute is carried out to the reaction tower. Supply dry ore into the inside, blow the reaction gas from the wind box of the concentrate burner,
The smelting reaction is completed in the reaction tower. At this time, the ratio between the dry ore and the reaction gas is set considering the physical quantity balance and the heat balance.

In operation, it is important to maintain the actual supply amount of dry ore and reaction gas at the above-mentioned set value with high accuracy. For example, if the amount of dry ore supplied to a certain amount of gas for reaction is too high, the quality of the obtained Kawa, the melt temperature of the Kawa and Karami will decrease, and the viscosity of Kawa and Karami, especially Karami will be high. Therefore, it becomes difficult to discharge it outside the furnace, which causes a serious trouble in operation. On the contrary, if the amount of dry ore supplied is too small, the quality of the river and the temperature of the molten metal will rise excessively, which will cause melting of the furnace wall. Therefore, the difference between the actual dry ore supply amount and reaction gas amount and their set values can be accurately detected, and the dry bottle supply amount from the relay bottle to the concentrate burner and the reaction gas supply to the wind box. Adjusting the amount is a very important control item in operation.

The reaction gas can be installed in a relatively good environment such as a flow meter and a flow rate controller, and the reaction gas itself can be managed accurately because it is cleaned through a filter. However, the supply amount of dry ore is determined, for example, by providing an impact plate between the end of the slicing conveyor and the concentrate chute, and determining the amount of impact on the impact plate during the free fall of the dry ore. There is no choice but to use such a method, and there is a high possibility that a large error will occur due to the state of adhesion of dry ore etc. to the impact plate. Therefore, the reliability of the value obtained by the impact plate is low, and in fact, the dry ore supply amount is adjusted so as to maintain the optimum furnace condition while monitoring the reactor condition,
In some cases, the measured values obtained from the impact plate have to be ignored.

In recent years, demands for labor saving, resource saving, and cost reduction have become strong, and as a result of this, attempts have been made to significantly increase the treatment amount by using a conventional smelting furnace, and have been implemented. . In order to surely and stably meet such requirements, the above-mentioned difference between the actual supply amount of dry ore and the set value has become a serious problem. That is, while monitoring the conventional furnace condition, the difference between the actual dry ore supply amount and the set value is read to adjust the actual dry ore supply amount to maintain the optimum furnace condition and the operating method is close to the equipment limit. Even if it is applied to the operation, it is difficult to expect the operation to be stabilized. Then, a highly accurate method of measuring the actual dry ore supply amount that can solve this problem has been studied, but a sufficient method has not been proposed yet.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object thereof is to provide a more accurate method of adjusting the supply amount of dry ore.

[0010]

According to the method of the present invention for solving the above problems, an undried smelting raw material is cut out from a storage bottle, the smelting raw material is dried in a drying facility, and the obtained dry ore is relayed. The amount of dry ore in the relay bottle is measured at a desired constant time interval t (unit: minutes) in a supply facility that continuously or simultaneously supplies the dry ore to the smelting furnace from the relay bottle. , The measured value a _n (unit ton) is stored, and when the number of measurements is m, the measured value a _n of the nth time and the measured value a _nm of m times before are used to calculate the numerical formula 4, the mathematical formula 5, and the mathematical formula 6. The raw material supply rate M _C (dry ton / hour) is calculated by using, and the feed rate from the relay bottle to the smelting furnace is corrected based on the calculated value. The amount of raw material supplied is calculated by using the calculated value, and the feed rate of dry ore from the relay bottle to the smelting furnace is adjusted each time based on the calculated value. Therefore, the correction coefficient k is preferably 0.8.

[0011]

## EQU4 ## C _n = a _n-1 × k + a _n (1-k)

## EQU00005 ## _C.sub.n-m = _a.sub.n-m- 1.times.k + _a.sub.n-m (1-k)

[Equation 6] Here, k is a correction coefficient for correcting the influence of the load collapse of the dry ore in the relay bin, and takes a value of 0 ≦ k <1. C _n and C _n-m are the dry ore amounts in the relay bottle after correction, and b is the water content (%) on a wet basis of the dry ore.
_Where C _mt is the amount of undried smelting raw material (tons) supplied to the drying equipment from the storage bottle during the time mt, and d is the moisture content of the undried smelting raw material on a wet basis ( %). The moisture content on a wet basis in b and d above
(%) Is the amount of water relative to the total amount (dry amount + water amount)
Means a percentage.

[0012]

In the method of the present invention, the amount of dry ore in the relay bottle is measured at a constant time interval t, and the period t is calculated by using the moving average of the amount of dry ore supplied to the smelting furnace during the time mt. The reason for adjusting the supply rate at is to minimize the effect of fluctuations in the measured values on the supply amount due to the collapse of the dry ore load in the relay bottle. It is necessary to determine t and m in consideration of the size and shape of the relay bottle to be used, and the residence time of kawa and kalami in the smelting furnace. Therefore, when applying the method of the present invention, it is necessary to determine t and m in advance based on these specifications.

[0013] For example, t must be a time that is controllable before a significant portion of the karami in the smelting furnace is replaced, however long. To give an example, the inner size is 6
m with a length of 20 m and an effective volume of 50 m ³ with a smelting furnace 1
When operating at a concentrate throughput of 800 tons / day, t is 5
Minutes and m are optimally set to 12.

In the formula underlying the method of the invention:
Although the correction coefficient k is used, this is a coefficient for better correcting the influence of the collapse of dry mine load in the relay bin. Of course, as described above, t and m are selected so as to minimize the fluctuation of the measured value due to the collapse of the dry ore load in the relay bottle, but this dry ore load collapse occurs relatively slowly. In some cases, it may occur very rapidly. In the present invention, the measured value at the time of the measurement of the calculation target and the measured value immediately before that are weighted to obtain the average value of both, and the calculation is performed based on the average value, and the calculation is performed by the above-mentioned equation 6. Try to make the impact smaller. Therefore, the value of k takes a value in the range of 0 ≦ k <1, and the value depends exclusively on the structure of the relay bin and the method of measuring the amount of dry ore in the relay bin. In the normal case, k is set to 0 and there is no problem, but more preferably, it is desirable to obtain the optimum value of k in advance.

As a method for measuring the amount of dry ore in the relay bottle, various level meters such as a souding type, an ultrasonic type, a microwave type and an X-ray type can be used. Applicable. Further, the method of supplying dry ore into the concentrate chute from the relay bottle is not a problem as long as it uses a device capable of quantitative supply, for example, a screw conveyor or a belt conveyor may be used, and a rotary valve may be used. Is also good.

[0016]

EXAMPLES Next, examples of the present invention will be described.

(Embodiment) In the inner dimension, a width of 6 m, a length of 20 m, an effective volume of 50 m ^3, a molten metal reservoir, a diameter of 6 m, and a height of 6.5 m are provided, and four concentrates are provided at the top of the reaction column. A burner is provided, and each of the concentrate burners is provided with a cutting conveyor that supplies the dry ore to the relay bin capable of storing 100 tons of dry ore. The test operation was performed under the following conditions while supplying it to the concentrate burner.

Dry ore supply 90 tons / hour Auxiliary fuel (heavy oil) 300 liters / hour Blast rate 33000 Nm ³ / hour Oxygen enrichment 43% Target Kawa quality 62% Fe / SiO ₂ 1.05 in Karami

First, the supply amount of dry ore was measured by the conventional measuring method using an impact plate, and based on this, the operation was carried out for 3 days while monitoring the furnace condition (conventional example). During this time, the Kawa quality, Kawa temperature and Karami temperature were measured 27 times. As a result, the average Kawa grade was 62.19% with a standard deviation of 1.38%,
The average Kawa temperature was 1227.9 ° C, the standard deviation was 14.5 ° C, the average Karami temperature was 1237.9 ° C, and the standard deviation was 15.6 ° C.
Although the average kawa quality was close to the target kawa quality, the standard deviation was large. The large standard deviation was the same for the average Kawa temperature and the average Karami temperature. This standard deviation is an index showing the stable state of the furnace condition, and a large standard deviation is not preferable.

Next, the supply amount of the dry ore to the concentrate chute is adjusted to 5 minutes, the m is set to 12 and the k is set to 0, and the dry ore supply amount is adjusted for 3 days according to the method of the present invention. The test operation was performed (Example 1). The amount of dry ore in the relay bottle was measured by using a souding level meter manufactured by Matsushima Kiken Co., Ltd. Moisture content b of the dry ore is based on the drying equipment
The management target value in was used. In addition, smelting raw materials
Moisture content d on a wet basis is measured in advance for each raw material brand
Each raw material used, based on moisture content on a wet basis
Mixing ratio of undried smelting raw materials after mixing brands
The value estimated from was used.

During this period, the quality of the Kawa, the temperature of the Kawa and the temperature of the Karami were measured 26 times. As a result, the average Kawa grade is 61.87%,
The standard deviation was 0.91%, the average Kawa temperature was 1226.4 ° C, the standard deviation was 9.2 ° C, the average Karami temperature was 1233.3 ° C, and the standard deviation was 10.1 ° C. The average kawa quality was close to the target kawa quality, and the standard deviation became smaller. Moreover, the standard deviation of the Kawa temperature and the Karami temperature became smaller, and it was found that a better furnace condition was obtained. Therefore, it can be understood that the problem of adjusting the dry ore supply amount by the impact plate can be solved by adopting the method of the present invention.

Then, a test operation similar to the above was continued for about 3 days with k set to 0.8 (Example 2).

During this period, the quality of the Kawa, the temperature of the Kawa and the temperature of the Karami were measured 23 times. As a result, the average Kawa grade is 62.21%,
The standard deviation was 0.74%, the average Kawa temperature was 1232.1 ° C, the standard deviation was 7.3 ° C, the average Karami temperature was 1233.8 ° C, and the standard deviation was 8.5 ° C. The average kawa quality was close to the target kawa quality, and the standard deviation was even smaller. This is k 0.8
By doing so, it is possible to correct the error in the measured value due to the variation in the presence of dry ore in the relay bin, and minimize the effect of sudden changes in the measured value due to load collapse in the relay bin. Shows that it is possible.

[0024]

EFFECTS OF THE INVENTION According to the method of the present invention, dry ore can be supplied without being affected by load collapse in the relay bottle, and as a result, variations in the quality of the river, the temperature of the river, and the temperature of the kelami can be suppressed. It is possible to stabilize the furnace conditions.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C22B 1/00 C22B 15/00

Claims (2)

(57) [Claims] 1. An undried smelting raw material is cut out from a storage bin, and the smelting raw material is dried in a drying facility, and the obtained dry ore is supplied to a relay bottle, or while being supplied, the dry ore from the relay bottle. the in continuously feeding supply equipment to the smelting furnace, to measure the dry ore weight in relaying bottle at desired fixed time intervals t (in minutes), to store the measured value a _n (units tons), measured when the number of times was defined as m, the number 1 by using the measured values a _nm before n th measurement values a _n and m times, number 2, calculates the material supply amount M _C (Drayton / hr) using a number 3 Then, the feed rate from the relay bottle to the smelting furnace is corrected based on the obtained calculated value, and the raw material supply amount is calculated by using the number 1, the number 2, and the number 3 each time after the measurement, and based on the calculated value. A method for adjusting the amount of dry ore supplied to a smelting furnace, characterized in that the rate of supply of dry ore from a relay bottle to the smelting furnace is corrected each time. ## EQU1 ## C _n = a _n-1 × k + a _n (1-k) ## EQU2 ## C _nm = a _{nm -1} × k + a _nm (1-k) ## EQU3 ## Here, k is a correction coefficient for correcting the influence of the collapse of the dry ore load in the relay bin, and takes a value of 0 ≦ k <1. C _n and C _nm are the amounts of dry ore in the relay bin after correction, b is the moisture content (%) on a wet basis of dry ore, and C _mt is the amount of dry ore from the storage bin during the time mt. It is the amount of undried smelting raw material supplied to the facility (ton), and d is the moisture content (%) on a wet basis of the undried smelting raw material. 2. The method for adjusting the amount of dry ore supplied to a smelting furnace according to claim 1, wherein k is 0.8.