JP3185242B2 - Operating method of flash furnace - 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 of operating a flash smelting furnace for producing a mat which is an intermediate for smelting a metal from copper or nickel sulfide ore.

[0002]

2. Description of the Related Art A flash smelting furnace called a smelting furnace using a sulfide concentrate as a raw material has many advantages as compared with other smelting furnaces, but also has many disadvantages. One of the disadvantages is as follows.

[0003] The concentrate, which is the main raw material of the flash smelting furnace, is usually fine particles having an average particle diameter of about 50 µm, which are blown into the reaction tower from a concentrate burner together with a flux, an auxiliary fuel, and reaction air. The temperature is raised in the tower, reacts and becomes a melt, falls into a settler, and is separated into a glue and a knot by the settler. It is known that concentrate particles and the like collide with each other during the fall and become enlarged (Journal of Japan Society for Resources and Materials Vol.106, No14, pp 873-879). However, it is also known that among the particles that fall on the settler, there are many particles that still fall with the original particle diameter. These fine particles disperse in the entanglement and reduce the separability of entanglement and glue in the settler. The separation between glue and glue in the settler depends on the specific gravity difference between glue and glue, but fine glue particles dispersed in the glue do not easily separate only by the difference in specific gravity, and the glue between the settler and the glue in the glue is not easily separated. Even after several hours of settling in a smelting furnace provided for separation, considerable glue particles do not settle out and are discharged out of the furnace with entanglement. Since the entangled waste is usually sold or rejected as entanglement, the glue in the entanglement, that is, the copper content, is directly lost copper.

[0004]

In the conventional operation using a flash smelting furnace or a smelting furnace, there is no effective method for separating fine glue in the above-described entanglement, and the copper grade in the entanglement is 0.6%. %. SUMMARY OF THE INVENTION An object of the present invention is to provide an operation method capable of promoting the sedimentation of the particles of the glue suspended in the settler of the flash smelting furnace or the encrusting furnace and reducing the loss of copper.

[0005]

According to a method of the present invention for solving the above-mentioned problems, a reaction column, a concentrate burner provided at the top of the reaction column, and one end connected to a lower portion of the reaction column are provided. In a method for operating a flash smelting furnace having a settler and a flue gas duct connected to the other end of the settler, the concentrate burner includes concentrate, repetitive smoke ash, flux, etc.
This is to supply a 0.5 mm solid bar.

[0006] The hardener to be added is produced by a normal operation of copper smelting, and is a glue adhered and solidified on a ladle.

[0007]

In the present invention, the reason for using solid barbecue is that it is the same as the glue produced in the flash furnace and does not change the glue quality, which is one of the operation control items of the flash furnace.
In addition, solid hardener is scientifically stable, does not cause a decomposition reaction involving endothermic reaction in the reaction tower, and can easily balance heat. Normally, this solid bar is in the form of a block, and is crushed before use.

[0008] If the particle size of the solid wax added is too small, the effect of accelerating the settling of the suspended glue particles in the entanglement does not appear. Conversely, if it is too large, it does not dissolve in the reaction tower and drops on the surface of the melt in the settler. And deposit as undissolved matter. For this reason, the grain size of the hard bar depends on the amount added, but is 0.1 to 0.5 m.
m is required.

[0009] The addition of 3% or more of the solids to the entanglement produces the above effect of promoting sedimentation, but more preferably 5% or more. When the addition amount of solid arsenic increases, a large amount of auxiliary fuel must be blown into the furnace from the concentrate burner in order to balance heat. This results in an increase in the heat load and the amount of generated exhaust gas in the reaction tower, and consequently reduces the concentrate processing amount. Therefore, the upper limit of the addition amount of solid must be comprehensively determined from the concentrate composition, the concentrate dissolution amount, the capacity of the exhaust gas treatment system, and the like, and cannot be determined unconditionally.

[0010] In the method of the present invention, it is also possible to use a copper-containing raw material corresponding to this instead of solid hardener. In addition, a method of spraying the coarse-grained or lump copper-containing raw material into the reaction tower by a chute or the like from the ceiling of the reaction tower instead of the concentrate burner may be considered, but such a method is only for rapid dissolution of the copper-containing raw material. However, as a result, the method of the present invention is inferior in the effect of reducing the amount of generated smoke ash.

[0011]

The present invention will be further described below with reference to examples.

(Study Example 1) Alumina tanman tube (T-
6) 200 g of the solidified self-melting furnace pulverized to about 2 to 3 mm, charged, and placed in an inert atmosphere from room temperature to 1200
℃ in about 2 hours, then 10, 4
The mixture was allowed to stand for 0, 70, 130, and 250 minutes, and then rapidly cooled.

[0013] The solidified tang was cut out in a depth of 1 cm together with the Tamman tube to obtain a layered sample piece. Except for the lowest part and the uppermost part of the obtained sample piece, the intermediate part was divided into five layers, and the first part, the second layer, the third layer, the fourth layer, and the fifth layer were formed from the bottom. Then, the copper content of each of these layers was analyzed. The results obtained are shown in Table 1.

[0014]

[Table 1]

The copper content in the entanglement is considered to be the sum of the suspension of the glue particles and the chemical dissolution, but under the conditions of this experiment, the copper content due to the chemical dissolution changes in the height direction. Therefore, the distribution of copper shown in Table 1 can be regarded as the distribution of suspended copper.

On the other hand, the sedimentation velocity of the glue particles in the entanglement is
Generally, it is expressed by the following equation. v = (2/3) * [g (ρ _m −ρ _s ) / η _s ] * (D / 2) ² * (η _s + η _m ) / (2η _s + 3η _m ) where v: Sedimentation velocity (cm / Sec) g: Gravitational acceleration (cm / Sec ² ) ρm: Density of glue (g / cm ³ ) ρs: Density of entanglement (g / cm ³ ) D: Particle diameter of glue (cm) ηm: The viscosity of the glue (poise) ηs is the viscosity of pouring.

Now, assuming that the glue particles are uniformly dispersed in the leash at first, and that all the glue particles are settled uniformly according to the above equation, the copper quality in the leash is always constant regardless of the settling time. Is higher than the upper layer, and if the average of the upper layer to the lower layer is averaged, the longer the settling time, the lower the copper content should be.

However, in Table 1, the settling time 40
However, when the settling time is 70 minutes or more, the copper content is almost constant, the copper content is almost constant, and the relationship with the settling time can be found. Absent. Further, when these entanglements were confirmed by the bromo-methanol method, it was found that about 0.3% of copper was present as glue particles.

This indicates that the glue particles having a certain size or more are settled at the settling time of 70 minutes, and the remaining fine glue particles do not obey the above formula and remain in the entanglement. In this example, the depth of the melt in the Tamman tube is about 7 cm. Using this, the size of the particles that settle out in 70 minutes according to the above equation is approximately 100 μm. Therefore, fine particles having a particle size of less than 100 μm do not exhibit the behavior according to the above equation, and are still present in the wrinkle after a long settling.

(Study Example 2) Alumina tanman tube (T-
Into 6), 200 g of water granulation was charged, and 20 g of coarsely ground solid copper shown in Table 2 was added to the surface, and the temperature was raised to 1200 ° C. in a deoxidized high-purity Ar atmosphere.
Each was kept at 1200 ° C. for 0, 1, and 2 hours. Thereafter, the Tamman tube was taken out of the furnace and quenched. After coagulation, the amount of suspended glue in the lees was determined by the bromethanol method.

[0021]

[Table 2]

For the purpose of comparison, similar examination experiments were carried out with no addition of solid arsenic and with holding times of 0, 1, 2, 3, and 4 hours. The results are shown in Table 3.

[0023]

[Table 3]

From Table 3, it can be seen that the addition of the coarse grained hard rice to the entangled surface lowers the amount of suspended mold, and the degree of decrease in the amount of suspended mold with respect to the holding time is remarkable.

Considering Study Example 1 and Study Example 2 together,
It is presumed that when the coarse glue particles added to the surface of the entanglement settle down in the entanglement, fine suspended glue particles were absorbed by the difference in sedimentation speed, and the fine glue particles floating in the entanglement were reduced.

From the above findings, it is effective to reduce the size of the suspended glue particles to 100 μm or more in order to reduce the glue particles suspended in the entanglement. It can be seen that it is effective to add the glue particles to the leech surface as an adsorbent.

Example 1 A reaction tower having an inner diameter of 1.5 m and a height from the settler surface to the ceiling of the reaction tower of 3.5 m, and a brick having an inner diameter of 1.5 m and a settler portion length of 5.25 m were prepared. Using a small test flash furnace consisting of a settler section and a flue gas,
u 30.4%, Fe 27.0%, S31.8%, S
79 parts by weight of 4.6% copper concentrate of iO2, SiO2 8
9% by weight of 5% flux, 20.5% Cu, Fe
A dry mine consisting of 13.1%, S 9.4%, SiO2 6.9% fume ash and 12 parts by weight has a particle size of +0.1 to 0.5.
Cu 60.0 crushed so that mm occupies 80%
%, Fe 11.7%, and S23.0% were added so as to be 1.5% with respect to the dry mine.
Days of operation. In addition, the addition amount of solid arsenic of Case 2 is 2.5% of dry mine, and that of Case 3 is 5%. Further, as a comparative example, a test was performed without adding hard copper. The obtained results are also shown in Table 4.

[0028]

[Table 4]

From Table 4, the effectiveness of the present invention is supported by a bench scale test using a small flash furnace. A secondary effect is a reduction in the rate of smoke ash generation. This is presumably because the adhesion of particles such as fine concentrate to the coarse glue particles in the reaction tower is promoted.

[0030]

In the method of the present invention, the coarse solid copper or copper-containing raw material supplied to the concentrate burner together with the concentrate, etc., removes heat from the combustion gas of the concentrate and auxiliary fuel and the furnace wall in the reaction tower. Receiving, melting and dropping on the surface of the settler, forming relatively large glue particles. These glue particles settle while absorbing fine glue particles, and reach the glue layer below the leech layer. For this reason, the amount of suspended glue during entangling can be reduced. In addition, at the time of collision of particles in the reaction tower, since larger glue particles are present, fine particles can be absorbed by larger particles, and as a result, the smoke ash generation rate can be reduced.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-13543 (JP, A) JP-A-3-183733 (JP, A) JP-B 64-96624 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) C22B 1/00-61/00

Claims (1)

(57) [Claims] 1. A reaction tower, a concentrate burner provided at the top of the reaction tower, a settler provided by connecting one end to a lower part of the reaction tower, and a smoke exhaust provided by connecting to the other end of the settler. In a method for operating a flash smelting furnace having a path, the concentrate burner has a grain size of 0.3% together with concentrate, repeated smoke and flux.
A method for operating a flash smelting furnace, characterized in that a solid solder of 1 to 0.5 mm is supplied.