JPS6055576B2 - Method for adjusting the amount of fuel supplied to the shaft section in flash-smelting furnace operation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting the supplied fuel when both heavy oil and pulverized coal are supplied to the shaft portion as fuel in the operation of a flash furnace.

For the operation of a flash furnace, the composition of raw materials such as ore, copper slag, smoke ash, and solvent is analyzed and determined, and the target Cu content% of the plate produced using these raw materials is determined. From this value, the S% of the fracture, Fe%,
At the same time, the Cu% of silver produced is estimated.

Also, the ratio of the amount of Fe to the amount of silicic acid in Hime (Fe/SiO2)
Set the amount, and calculate the amount of coating, amount of molten material, and amount of solvent from the mass balance calculation. In addition, the amount of oxygen required for the reaction of Fe, S, etc. necessary for the production of Kaji and Hime is calculated. On the other hand, the target plate temperature that is considered to be the most desirable for operation is set based on the reaction temperature, separation of cracks and cracks, removal of these from the furnace, etc. The temperature (shaft gas temperature) at the reaction end position in the shaft portion is generally assumed to be 140±10 to 2 CfC higher than the target plate temperature in a flash furnace. The amount of auxiliary fuel required to be supplied to the shaft to maintain this shaft gas temperature is determined by calculating the heat balance of raw material reaction heat, heavy oil combustion heat, blown air and other sensible heat, and the amount of heat dissipated from the shaft. demand. The amount of air required for combustion of this auxiliary fuel is calculated taking oxygen efficiency into consideration, and the amount of air required for the reaction of the raw materials is added to this to calculate the theoretical amount of air to be blown to the shaft section. Based on this calculated value, the amount of fuel and air supplied to the shaft portion is controlled. Therefore, changes in raw material charging amount, blending brand, blending ratio, target Cu% of production plate, target Fe/SlO2 of production plate,
When there is a change in the target breaking temperature, that is, a change in the calculation basis, the amount of air to be blown changes and the amount of fuel to be supplied changes accordingly.

In addition, the temperature of the produced plate can be measured using an immersion thermocouple or the like when it is removed from the furnace according to the requirements of the converter, but the temperature of the produced plate may affect the operation of the converter. In order to minimize the temperature fluctuation of the production plate, the applicant filed a patent application No. 49-17548.
No. 2, filed an application for a method for adjusting the amount of fuel supplied to the shaft in the operation of a flash-smelting furnace. However, the method for adjusting the amount of fuel supplied uses only heavy oil as the fuel.

Due to the recent rise in the price of heavy oil, the use of pulverized coal as a cheaper alternative fuel has been considered, and pulverized coal is extracted from the middle of the concentrate burner installed at the top of the flash furnace shaft, which supplies concentrate, heavy oil, and hot air. If the amount of pulverized coal is supplied, changes in the amount of pulverized coal supplied will immediately affect the thermal balance of the shaft portion, but it is not easy to freely adjust the amount of both heavy oil and pulverized coal supplied. Ta. The present invention improves the method of adjusting the amount of fuel supplied to the shaft section in which only heavy oil is supplied in the operation of a flash furnace. It is an object of the present invention to provide a method for adjusting the amount of fuel supplied to a shaft portion, which can minimize fluctuations in the amount of fuel supplied to the shaft portion.

Now, when using both heavy oil and pulverized coal as fuel, if the ratio of the amount of heavy oil used (K9lH) to the amount used of pulverized coal (K9lH) is 1:P, the composition of the charge, the target Cu of the produced plate
%, the target breaking temperature, and other factors to calculate the heat balance of the shaft portion, and calculate the required amounts of both fuels according to the following equations (1) to (4).

However, 8: Required amount of heavy oil (K9lH) 8: Required amount of pulverized coal (K9lH) Required heat amount of the shaft part other than sensible heat of exhaust gas due to combustion of all fuel (KcallH) Q1: Combustion heat of all fuel and fuel combustion Shaft heat input other than sensible heat of air (KcalI
H) Qel; Heavy oil effective calorific value (Kcallkg) Qe2
; Pulverized coal effective calorific value (KcaIlk9) P; heavy oil amount 1
Pulverized coal usage ratio (weight ratio) q1; Heavy oil calorific value (Kcallk9) Q2; Pulverized coal calorific value (Kcallk9) a1; Theoretical air amount required for combustion of heavy oil (NdIkg) A
2; Theoretical air amount required for combustion of pulverized coal (Nd'K9)q
&; Sensible heat of air for fuel combustion (KcallNi) g1; Sensible heat of exhaust gas due to heavy oil combustion at target shaft gas temperature (Tg) (Kcall kg) &; Pulverized coal at target shaft gas temperature (Tg) Sensible heat of exhaust gas due to combustion (Kcallk9) Equation (1) is the amount of heat required in the shaft that is insufficient due to the heat of arrangement of Fe and S in the ore, the sensible heat of the air necessary for this oxidation, etc. It calculates a value that compensates for by the combustion heat of the fuel,
Since air is required for combustion of fuel, combustion exhaust gas is generated, and as this exhaust gas exits from the shaft at a high temperature, part of the total calorific value of the fuel is used to compensate for the lack of heat in the shaft. This was established in order not to contribute to the situation.

Normally, operations are carried out based on the amount of heavy oil and pulverized coal determined by equations (1) and (2) above, and when the raw material charging amount, blending, target Cu% of produced plate, etc. change, heat Calculate the balance and change the amount of heavy oil and pulverized coal.

Next, the temperature of the produced kettle is measured, and when the difference from the target temperature is less than a set allowable value X°C, the amount of fuel to be supplied is determined by increasing or decreasing the amounts of heavy oil and pulverized coal in proportion to only the temperature difference.

In addition, when the difference between the temperature of the plate produced and the target temperature is more than the set allowable value The required amount of fuel is determined by correcting the heat balance of the shaft portion, and the amount of fuel to be supplied is determined by adding or subtracting a correction amount proportional to the temperature difference.

Generally, when changing the temperature of a substance, even if it is heated or cooled, it takes time to raise and lower the temperature depending on the heat capacity of the substance, and the larger the amount of heating or cooling heat per unit time, the more the temperature will change. The time required will be shorter.

Even if the amount of fuel is increased or decreased in order to modify the temperature of the production breakthrough, it will take some time for the effect to appear. If the temperature of the production plate deviates from the target value by more than the set allowable value, even if the fuel is simply increased or decreased in proportion to the temperature difference,
The effect of increasing or decreasing fuel does not necessarily appear in proportion to the temperature of the production breakout, and it is also unclear how long it takes for the effect to appear. Therefore, the part where the fuel is adjusted in stages (the amount of fuel modified by modifying the shaft gas temperature)
The amount of fuel to be supplied is corrected using both of the following: and a portion that adjusts the amount of fuel in proportion to the difference between the temperature of the production tank and the target value. The purpose of modifying the shaft gas temperature is to bring the temperature of the production fracture closer to the target value as quickly as possible.

That is, when the difference between the produced plate temperature and the target plate temperature is less than or equal to a preset allowable value x° C., the feed amounts of heavy oil and pulverized coal are corrected according to the following equations (5) to (9).

~ Corrected pulverized coal supply amount (K9'H) C1 Proportional correction amount for production plate temperature difference of heavy oil (KglH) C2 Proportional correction amount for production plate temperature difference of pulverized coal (K9lH) E1 Measured temperature of production plate (℃) E
Target temperature for 2nd production (℃) Kt8. Heavy oil correction amount (K9lH) that changes depending on the ratio of pulverized coal used per 1°C temperature difference K1; Difference in breaking temperature of heavy oil 1°C
Preset correction amount per 1 degree Celsius difference in pulverized coal plate temperature (K9lH) K2; Preset correction amount per 1°C difference in plate temperature of pulverized coal (K9lH) Furthermore, the difference between the produced plate temperature and its target temperature is the set allowable value
If the temperature is above ℃, correct the shaft gas temperature according to the following formula.

However, Tg: Shaft gas temperature after correction (℃) T,'': Shaft gas temperature before correction (℃) ΔT,; When the difference between production failure temperature and target failure temperature is more than the preset tolerance value X℃ The shaft gas correction temperature is a predetermined temperature Y°C.

When the production plate temperature is higher than the target breakdown temperature, it is a negative value, and when the production plate temperature is lower than the target breakdown temperature, it is a positive value. 0
Correct the shaft gas temperature Tg according to formula 0, and calculate this T,
Accordingly, we recalculated equations (3) and (4) and equations (1) and (2) to find the corrected Tsukasa and B2, and calculated them using these eight, B2, and equations (7) and (8). C1, C2 as (5), (
6) Calculate the corrected heavy oil supply amount and corrected pulverized coal supply amount using the formula.

The theoretical gas temperature in the shaft immediately after the completion of the metallurgical reaction is 140±10~140±10% higher than the target plate temperature.
Since it is assumed that it is 20℃ higher, in order to correct the temperature of the production plate, the previous gas temperature was revised by increasing or decreasing this temperature by a predetermined temperature of Y℃. The shaft gas temperature is used as a reference, and the heat balance of the shaft is recalculated to increase or decrease the amounts of heavy oil and pulverized coal.

This Y° C. is determined by balancing the size of the furnace, the frequency of measuring the temperature of the produced plate, the average amount of plate accumulated inside the furnace, and the quantity of fuel K1 and K2 corrected in proportion to the temperature difference of the produced plate.

In the example described below, K1=1.25kgIH. K2
=2.0k91H,. Y=4°C, and the set tolerance x for the difference between the measured temperature of the produced plate and the target plate temperature was ±5°C.

This set allowable value is determined by taking into account the temperature of supply to the converter, the separability of silver from silver, and other factors. In the above, the fuel supply amount was corrected for both heavy oil and pulverized coal, and the ratio of the amounts used of both fuels was always set at 1:P.
Next, a case will be described in which one of the fuel oil and pulverized coal supplies is fixed and the supply amount of only the other one is increased or decreased.

These cases can also be implemented by making slight modifications to the above-described method. First, when the amount of heavy oil is constant, if the constant amount of heavy oil supplied is L'' (K9lH), the following (
'2'), (3), (4), (6''), (8''), and the required amount of pulverized coal and the corrected amount of pulverized coal are determined according to the [phase] formula. However, L″: Fixed heavy oil supply amount (K9lH) M: Necessary amount of pulverized coal (K9lH) ~″: Corrected pulverized coal supply amount (K9lH) C2″: Proportional correction amount of pulverized coal production breakdown temperature difference ( K9lH)
Other proviso is the same as above.

Equation (2'') is the amount of pulverized coal M required to compensate for the insufficient amount of heat in the shaft part by the effective amount of heat from pulverized coal after subtracting the effective amount of heat from the heavy oil supplied in a certain amount.
The correction due to the difference between the measured temperature and the target temperature for production failure is calculated as follows: If the difference is less than the set allowable value
), (8″) to increase or decrease the pulverized coal supply amount in proportion to only the temperature/degree difference, and if the difference is greater than the set allowable value Correct Tg, recalculate equations (3), (4), and (2') according to this Tg to find the corrected pulverized coal amount M, and then calculate (8'')
Calculate the corrected pulverized coal supply amount using the temperature difference proportional correction amount obtained using the formula.

Next, when the amount of pulverized coal is constant, if the constant pulverized coal supply amount is M'' (K9lH), the following (1''), (3
), (4), (5″), (7″) and [phase] According to the equation, the theoretical air amount required for the combustion of heavy oil heavy oil a1 = 11.0N Ik9 The theoretical air amount required for the combustion of pulverized coal! =7.0N i1k9 Sensible heat of air for fuel combustion q&=140Kca11N
B Sensible heat of exhaust gas due to heavy oil combustion at the theoretical shaft gas temperature (Tg) g1 = 5800 Kca1 Ik9 Sensible heat of exhaust gas due to pulverized coal combustion at the theoretical shaft gas temperature (Tg) &=3500 Kca11 k9 Charge amount,
9, Q1 calculated from the composition, target i & Cu grade, etc. using the above values, from equations (3) and (4), from equation (1), from equation (2), i.e. heavy oil amount 1115.5k91H, pulverized coal amount 557
．． It was operating at 8k91H.

When the measured temperature E1 of the production head is 1214°C, this temperature is within the set tolerance value ±5°C, so equations (7) to (9) are used to calculate the proportional correction amount of the production head temperature difference.

From equations (9) and (7), from equations (8) 1′3 υ●υ′JV●U−−1◆J(5), (
6) Revised from Eq.

Example 2 Seven hours after the fuel was corrected in Example 1, the measured temperature of the production tank was 1203C. Since this temperature was lower than the target temperature and more than the set allowable value ±5°C, the temperature was changed to 0a first.
Correct the shaft gas temperature by the formula.

Gogure-JlVUυ● τ-1uu&tνUsing this shaft gas temperature, the heat balance is corrected by equations (1) to (4) to determine the necessary amount of heavy oil and pulverized coal to be supplied to the shaft portion.

Next, the production failure temperature difference proportional correction fuel amount is determined from equations (7) and (8).

The corrected fuel amount is obtained from equations (5) and (6) and the fuel supply amount is changed.

Example 3 Use ratio of pulverized coal to heavy oil under the conditions of Example 1 P = 4
．． Changed to 0.

The amount of heavy oil and pulverized coal at this time is E1 = 1206℃ when the temperature of production failure is measured from equations (1) and (2). Since this temperature is within the set allowable value, (7) to (9) Calculate the production breakdown temperature difference proportional correction amount using the formula.

Formulas (5) and (6) were modified from formula (9).

Example 4 Under the conditions of Example 1, when the fuel oil supply amount is fixed at 400k91H and the fuel supply amount is adjusted only with pulverized coal, and the production slope temperature is 1213'C, from equation (2'), AVVVVV number - Since the Vl temperature difference is within the allowable value, from equations (6″) and (8″),
＾１ ＾＾八 ＾＾＾＾＾＾＾＾＾） One household＾
Example 5 When a breakdown temperature of 1207 C was measured 7 hours after the amount of pulverized coal was corrected in Example 4, the temperature difference exceeded the allowable value, so the shaft gas temperature was corrected using a side equation.

Using this shaft gas temperature, (7), (3), (4)
Calculate the required amount of pulverized coal to be supplied to the shaft by correcting the heat balance using the formula.

1U Kaoru 4J●ν (6″), (8″) From formula breath t −1V−υ●riWXV4V5ν～to〃vugu1q
Corrected to 1.

Example 6 Under the conditions of Example 1, when the supply amount of pulverized coal is fixed at 1500k91H per month and the fuel supply amount is adjusted only with heavy oil, and the production failure temperature is 1206°C, modify from formula (1'') did.

Example 7 Under the conditions of Example 1, the supply amount of pulverized coal was fixed at 1500 kg 1H, and the operation was carried out by adjusting the fuel supply amount only with heavy oil, and until then the shaft gas temperature was 1358 ° C. and heavy oil was being supplied. .

Thereafter, the mound temperature was measured and found to be 1220°C.
Since the temperature difference exceeds the allowable value, the shaft gas temperature is corrected using the [stock] formula, and using that shaft gas temperature, (1"
), (3), and (4) to correct the heat balance and determine the required amount of heavy oil to be supplied to the shaft. Revised.

As described above, the present invention uses both heavy oil and pulverized coal as fuel to be supplied to the shaft part, and adjusts the supply amount so as to keep the ratio of both fuels constant while minimizing fluctuations in the temperature of the production breakout. Furthermore, since the supply amount of one fuel can be kept constant while the supply amount of the other fuel can be adjusted, inexpensive pulverized coal can be used efficiently.

Claims (1)

[Claims] 1. During the operation of a flash-smelting furnace in which heavy oil and pulverized coal are supplied to the shaft portion at a feed weight ratio of heavy oil to pulverized coal of 1:P, the temperature of ① produced is measured, and the temperature of If the difference from the target temperature in ■ is less than the set allowable value
), and if the temperature difference is above the set allowable value X℃, correct the target shaft gas temperature using the following equation (10), and use this value to calculate the following equations (1) to (9). A method for adjusting the amount of fuel supplied to the shaft part in the operation of a flash furnace, characterized by adjusting the output temperature by changing the amount of heavy oil and pulverized coal supplied according to calculations. B_1=(Q_0-Q_1)/{(Q_e_1+Q_e
＿2)×P}(1)B_2=B_1×P(2)Q_e_
1=q_1+a_1×q_a-g_1(3)Q_e_2
=q_2+a_2×q_a-g_2(4)A_1=B_
1-C_1(5) A_2=B_2-C_2(6) C_1=K(E_1-E_2)(7) C_2=C_1×P(8) K=K_1K_2/(K_1×P+_K_2)(9)T
_g=T_g'+ΔT_g (10) However, B_1: Required amount of heavy oil to maintain the shaft gas temperature at the target temperature (kg/H) B_2; Required amount of pulverized coal to maintain the shaft gas temperature at the target temperature ( kg/H)Q_
0; Required heat amount of the shaft part other than sensible heat of exhaust gas due to combustion of all fuel (Kcal/H) Q_1; Shaft part heat input amount other than combustion heat of all fuel and sensible heat of fuel combustion air (Kca
l/H) Q_e_1; Heavy oil effective calorific value (Kcal/kg
) Q_e_2; Pulverized coal effective calorific value (Kcal/kg) P
; Pulverized coal usage ratio (weight ratio) when the amount of heavy oil is 1
_1; Heavy oil calorific value (Kcal/kg) q_2; Pulverized coal calorific value (Kcal/kg) a_1; Theoretical air amount required for combustion of heavy oil (Nm^3/kg) a_2;
Theoretical amount of air required for combustion of pulverized coal (Nm^3/kg)q
_a; Sensible heat of air for fuel combustion (Kcal/Nm^3) g
_1; Sensible heat of exhaust gas (Kcal/kg) g_2 due to heavy oil combustion at target shaft gas temperature (T_g)
Sensible heat of exhaust gas (Kcal/kg) A_1 due to pulverized coal combustion at target shaft gas temperature (T_g);
Corrected heavy oil supply amount (kg/H) A_2; Corrected pulverized coal supply amount (kg/H) C_1; Production of heavy oil ■ Temperature difference proportional correction amount (kg/H) C
_2; Production of pulverized coal ■ Temperature difference proportional correction amount (kg/H) E
_1; Measured temperature of production ■ (℃) E_2; Target temperature of production ■ (℃) K; ■ Corrected amount of heavy oil (kg/H) that changes depending on the usage ratio of pulverized coal per 1 degree Celsius temperature K_1; ■ Temperature of heavy oil Preset correction amount per 1℃ difference (kg/H) K_2; Preset correction amount per 1℃ temperature difference (kg/H) T of pulverized coal
＿g; Shaft gas temperature after correction (℃) T_g′; Shaft gas temperature before correction (℃) ΔT_g; Production ■Temperature and target ■ Shaft gas correction temperature when the difference between temperature is more than the preset tolerance value X℃ and a predetermined temperature of Y°C. If the production temperature is higher than the target temperature, it is a negative value, and if the production temperature is lower than the target temperature, it is a positive value. 2
During the operation of a flash-smelting furnace that supplies heavy oil and pulverized coal as fuel to the shaft section with a constant supply amount of heavy oil, the temperature of the produced ■ is measured, and the difference between the target temperature of the produced ■ and the set allowable value X
If the temperature difference is below the set tolerance value X℃, correct the target shaft gas temperature using the formula (10) below. , depending on this value, the following (2'), (3), (4), (6
'), A method for adjusting the amount of fuel supplied to a shaft section in the operation of a flash-smelting furnace, characterized in that the amount of pulverized coal supplied is changed according to the calculation of formula (8') to adjust the output temperature. M={(Q_0-Q_1-Q_e_1)×L'}/Q_
e_2(2')Q_e_1=q_1+a_1×q_a-
g_1 (3) Q_e_2=q_2+a_2×q_a-g
_2(4)A_2'=MC_2'(6')C_2'=
K_2(E_1-E_2)(8')T_g=T_g'+
ΔT_g (10) where M: Required amount of pulverized coal to maintain the shaft gas temperature at the target temperature (kg/H) L': Constant heavy oil supply amount (k
g/H) A_2′; Corrected pulverized coal supply amount (kg/H) C_
2'; Production of pulverized coal ■ Temperature difference proportional correction amount (kg/H) Q
_0; Shaft part required heat amount other than sensible heat of exhaust gas due to combustion of all fuel (Kcal/H) Q_1; Shaft part heat input other than combustion heat of all fuel and sensible heat of fuel combustion air (Kc
al/H) Q_e_1; Heavy oil effective calorific value (Kcal/k
g) Q_e_2; Pulverized coal effective calorific value (Kcal/kg)
q_1; Calorific value of heavy oil (Kcal/kg) q_2; Calorific value of pulverized coal (Kcal/kg) a_1; Theoretical amount of air required for combustion of heavy oil (Nm^3/kg) a_2; Theoretical amount of air required for combustion of pulverized coal ( Nm^3/kg) q_a; Sensible heat of air for fuel combustion (Kcal/Nm^3) g_1; Sensible heat of exhaust gas due to heavy oil combustion at target shaft gas temperature (T_g) (Kcal/kg) g_2; Sensible heat of exhaust gas due to pulverized coal combustion (Kcal/kg) at shaft gas temperature (T_g) E_1; Measured temperature of production (°C) E_2; Target temperature of production (°C) K_2; ■Temperature difference of pulverized coal 1 Preset correction amount per °C (kg/H) T_g; Shaft gas temperature after correction (°C
) T_g'; Shaft gas temperature before correction (℃) ΔT_g
; Shaft gas correction temperature when the difference between the output ■ temperature and the target ■ temperature is more than a preset tolerance value X °C, which is a predetermined temperature Y °C. If the production temperature is higher than the target temperature, it is a negative value, and if the production temperature is lower than the target temperature, it is a positive value. 3
During the operation of a flash-smelting furnace that supplies heavy oil and pulverized coal as fuel to the shaft section with a constant supply of pulverized coal,
If the difference from the target temperature of production (■) is less than the set allowable value In the above case, correct the target shaft gas temperature using the following formula (10), and use this value to determine the following (1'), (3), (4), (
5') A method for adjusting the amount of fuel supplied to the shaft section in the operation of a flash-smelting furnace, characterized in that the amount of heavy oil supplied is changed in accordance with the calculation of formula (7') to adjust the output temperature. L={(Q_0-Q_1-Q_e_2)×M'}/Q_
e_1(1')Q_e_1=q_1+a_1×q_a-
g_1 (3) Q_e_2q_2+a_2×q_a-g_
2(4)A_1'=L-C_1'(5')C_1'=K
_1(E_1-E_2)(7')T_g=T_g'+Δ
T_g (10) However, L: Required amount of heavy oil to maintain the shaft gas temperature at the target temperature (kg/H) M': Constant pulverized coal supply amount (k
g/H) A_1′; Corrected heavy oil supply amount (kg/H) C_1
'; Heavy oil production ■ Temperature difference proportional correction amount (kg/H) Q_0
; Shaft part required heat amount other than sensible heat of exhaust gas due to combustion of all fuel (Kcal/H) Q_1; Shaft part heat input other than combustion heat of all fuel and sensible heat of fuel combustion air (Kcal
/H) Q_e_1; Heavy oil effective calorific value (Kcal/kg)
Q_e_2; Pulverized coal effective calorific value (Kcal/kg) q_
1; Heavy oil calorific value (Kcal/kg) q_2; Pulverized coal calorific value (Kcal/kg) a_1; Theoretical air amount required for combustion of heavy oil (Nm^3/kg) a_2; Theoretical air amount required for pulverized coal combustion ( Nm^3/kg) q_a; Sensible heat of air for fuel combustion (Kcal/Nm^3) g_1; Sensible heat of exhaust gas due to heavy oil combustion at target shaft gas temperature (T_g) (Kcal/kg) g_2; Exhaust gas sensible heat (Kcal/kg) due to pulverized coal combustion at shaft gas temperature (T_g) E_1; Measured temperature of production (■)
°C) E_2; Target temperature for output (°C) K_1; Preset correction amount per 1°C temperature difference in heavy oil (kg/H) T_g; Shaft gas temperature after correction (°C)
T_g′; Shaft gas temperature before correction (℃) ΔT_g;
Output ■ Temperature and target ■ Temperature difference is preset tolerance value X℃
Shaft gas correction temperature in case of above, which is a predetermined temperature Y°C. If the production temperature is higher than the target temperature, it is a negative value, and if the production temperature is lower than the target temperature, it is a positive value.