SU1069875A1 - Method of processing loose slags - Google Patents

Abstract

METHOD OF PROCESSING OF DISSOLVING ISHAKS, including cooling of the slag drained from the furnace in modes that ensure its decomposition, followed by separation into metallic and nonmetallic composition in the energy carrier flow, characterized in that it is New. In order to extract silage from the slag, the separation is carried out in an upward air flow moving at a speed of 3-6 m / s, at a concentration of 0.2-2.5 kg / nm of air supplied to the separation of slag. S

Description

O5 00

cx |

The invention relates to ferrous metallurgy, specifically to the separation of metal crowns from slag, primarily for the processing of disintegrating slags of silicocalcium production. There is a known method for extracting silico-calcium from slag, in which silicocalcium from a furnace is poured into a flat separable mold through a hopper filled with dry sand to separate metal and slag. Lighter than the slag, the alloy flows into the mold, and the slag remains in the digger. The resulting slag block contains a significant amount of metal. After cooling, large pieces of metal from the blocks choose the immobile and the rest completely. Send to the dumper G13. The disadvantages of this method are the large losses of metal with slag and the difficult working conditions of slag workers. Closest to the present invention is a method for processing crumbling slags from the production of ferroalloys. In this method, the slag after discharge from the furnace, cooling and disintegration is fed to an air separator, where the separation of metal and undissolved slag pieces from the small fractions of slag in the field of action of centrifugal forces and closed air streams is performed. Freed from dust particles, the material is fed to magnetic separation into the zone of action of weak and strong magnetic fields, in which C2 metal is extracted. However, the air separator does not provide satisfactory separation of the slag into metal and non-metal parts, and the use of magnetic separation for recovery, silicocalcd is unacceptable since the latter is related to the discharge of non-magnetic materials. The purpose of the invention is to increase the efficiency of the recovery of silicocalcium from slag. This goal is achieved by the fact that in the method of processing scattered slags, including cooling the slag drained from the furnace in modes that both bake decay, followed by separation into metallic and nonmetallic components in the flow of energy carrier, the separation is conducted in an upward air flow moving at 3-6 m / s at the concentration of air supplied to the separation of slag 0.2-2.5 kg / nm. The particle speed of motion (or critical velocity) is the velocity of the vertical air flow, at which the particle introduced into this stream is suspended (it soars. The speed of spin depends on particle size, roughness and shape of their surface, density, and also on dynamic viscosity of air flow, i.e., each particular particle has its own soaring speed. If the flow rate is greater than the soaring speed for a particle, the particle will move together with the air flow upwards, and if the speed is The flow will be less, then the particle will be deposited in this stream. In other words, in an air stream the particles will be separated at a given speed depending on their inherent properties. Considering the fact that not one particle is subjected to separation, but the particle flow the concentration of particles in the air flow or the intensity of the particles in the separation medium per unit of time will be affected. An analysis of the material composition and physicomechanical properties of the decomposed slags from Production 30 and 15% silicocalcium, showing t, the metallic and non-metallic components have skhodnyeznacheni specific density (Table 1). Table 1 At the same time, metallic inclusions are mainly present in the 2.5–0.315 mm class, i.e. in relatively large fractions (Table 2).

Table

Petrographic analysis of decomposition products shows that the silico-calcium alloy in the slag is not associated with the mineral component, but is presented in the form of rolled smooth particles with a tightly spherical surface. Slag particles have a loose, polished, uiepo-like surface and an indefinite shape. The values of the physical PROPERTIES of the metallic and nonmetallic components and the experimental verification of the separation of slag and metal in the upward air flow allows the selection of the initial parameters to neglect the process. The air flow rate is determined by calculation and refined under experimental conditions. The values of the experimental velocities of the particle soaring by 20–22% exceed the calculated ones. The values of the weight concentration are determined experimentally. The satisfactory performance of the process of separating the slag into a metallic and non-metallic component at flow rates from 3 to 6 m / s. and x values of the concentration of the material to be separated in the air flow from 0.2 to 2.5 kg / nm3. An increase in the air flow rate above 6 m / s leads to the fact that metal particles are carried along with the slag, and a decrease in the speed below 3 m / s leads to the precipitation of a large amount of slag particles together with the metal in the deposition bunker. The quality of the separation of the source material is influenced by the magnitude of its weight concentration in the air flow. A decrease in the weight concentration below 0.2 kg / nm of air leads to a reduction in the productivity of the process without improving the quality of the separation. In this case, with large. flow rates occur the active removal of metallic inclusions together with CO by slag. Increasing the weight concentration above 2.5 kg / Nm3 drastically reduces the separation efficiency due to the fact that the air flow, even at high speeds, has a relatively low energy consumption and does not ensure full interaction with the material flow. Example. Slags produced by silicocalcium, drained from the furnace, undergo silicate decomposition, which occurs due to the polymorphic transformation of calcium orthosilicate at

slow cooling in the temperature range from 525 to with an increase in the specific volume of approximately 1: 2%. The collapsed 1ilacs are accumulated in bunkers, over which they arrange receiving grids, limiting-. the fall of large pieces nerazavshshego | with slag for further processing. from hoppers by feeder and belt | The slag conveyor serves in the ALA device OLE of separating the slag into the metal and non-metal components in the upstream air flow. For the NIN section, the material is loaded into the apparatus of the super xy. The speed of the upward air flow in the apparatus is set based on the soar speed value of the particles of the boundary size. The size of the granular size is determined by examining the physical properties of the different.

Indicators of the extraction of alloy from slag produced by IC 30

Extraction of the metal into the coarse product is 86.5%.

fissile material. For donkeys, the coca ligature assesses a grain size of 0.315 mm as the separation boundary.

The weight concentration of the material separated in the apparatus at each moment of time is determined based on the volume of air flowing through the apparatus per unit of time due to a change in the performance of the feeder. For example, if 10 nm3 of air passes through the apparatus within a minute, then the capacity of the feeder should be within 2-25 kg / min.

With pneumatic classification of slags of 15 and 30% silicocalcium at an engine speed of 4-6 m / s and slag concentration in a flow of 1.8 kg / nm, an alloy extraction of 69-87% is obtained (Tables 3 and 4).

Table 3 Indicators of the extraction of alloy from slag produced by SC 15

 The recovery of the metal into the coarse product is 69.3%. The use of the proposed method makes it possible to reduce the loss of a valuable alloying alloy and increase the efficiency of its use in metallurgy.

Table The economic effect of 6t implementation of this method with a volume of processing of donkeys in 20 thousand tons due to the additional extraction of silicocalcium will be 102 thousand rubles. in year.

Claims (1)

METHOD FOR PROCESSING DISSOLVING SLAGS, including cooling the slag melted in the furnace in the modes ensuring its decay, with the subsequent separation into metallic and nonmetallic components in the energy carrier stream, characterized in that, in order to increase. to increase the efficiency of extracting silicocalcium from slag, the separation is carried out in an upward air flow moving at a speed of 3-6 m / s, with a concentration of 0.2-2.5 kg / nm ^{3 of} ioelectric delivered to the separation of slag. l