JP5505801B2 - High temperature slag treatment method - Google Patents

Description

  The present invention relates to a method for treating high-temperature slag.

  Conventionally, when separating the metal contained in steelmaking slag discharged at a high temperature of 1200 ° C or higher, as a pre-process of the separation work, the high-temperature slag is allowed to cool in the cooling pit for several hours to a temperature at which there is no danger of steam explosion After the cooling, in order to further proceed the cooling, a cooling step of cooling while sprinkling the cooling water for several hours was necessary. In addition, the slag after the cooling process was then classified and separated from the slag in large chunks, medium chunks and small chunks, while repeatedly passing through a crusher and a magnetic separator. Thus, the separated bullion may not be sufficiently separated from the slag, and it has been difficult to stably obtain a bullion with a high iron content.

  In contrast, the applicant of the present invention can efficiently recover the metal contained in the steel slag without causing a steam explosion or fire, and obtain a metal with a high iron content. Rotary cooler for the purpose of providing a recovery method and a method capable of recovering bullion contained in steelmaking slag without requiring excessive facilities and costs and suppressing dust scattering The steelmaking slag is charged in a high temperature state around 1000 ° C. inside, and by rotating the rotary cooler provided with protrusions on the inner surface of the shell, the steelmaking slag is cooled while applying a crushing action due to a drop impact, The technique which isolate | separates the bullion contained in steelmaking slag is disclosed (patent document 1).

  In the method for separating metal in steelmaking slag described in Patent Document 1, high-temperature steelmaking slag of 1300 to 1500 ° C discharged from the steelmaking process is cooled to 800 to 1250 ° C in a cooling pit (hereinafter referred to as primary cooling). After that, it is put into the rotary cooler through the hopper. At the entrance of the hopper, a lattice-shaped vibrating screen called a vibrating grizzly is installed, and the large ingots in the steelmaking slag are collected here. Next, the steelmaking slag that has passed through the vibration grizzly is charged into the rotary cooler while being in a high temperature state of about 800 to 1250 ° C. by a cutting device such as a vibration feeder. The rotary cooler has a structure with protrusions on the inner surface of the shell, and is cooled to 300 ° C. or lower while applying a crushing action by dropping impact to the steelmaking slag by rotating the shell (hereinafter referred to as secondary cooling), Metals contained in steelmaking slag can be separated. The steelmaking slag thus crushed and separated from the metal is then discharged from the exit chute onto the conveyor.

  The high-temperature slag temperature charged into the rotary cooler varies from about 800 to 1250 ° C. Conventionally, as a means of cooling such slag to 300 ° C or less by secondary cooling, slag is conventionally charged into the rotary cooler. The amount was set to about 70% (for example, 50 t / h) of the maximum input amount per unit time (for example, 75 t / h) at the maximum cooling capacity of the rotary cooler, and steady operation was performed. However, there is a problem that the efficiency of slag treatment is reduced by the control that always operates below the maximum processing capacity of the rotary cooler.

JP 2009-127094 A

  An object of the present invention is to provide a high-temperature slag treatment method capable of solving the above-described problems and improving the treatment efficiency in the slag cooling process.

The high temperature slag treatment method of the present invention made to solve the above problems is a high temperature slag treatment method in which the high temperature slag is primarily cooled and then secondarily cooled while moving inside the cooling device, The mass per unit time and the internal temperature of the slag after primary cooling are measured before the cooling device is charged to calculate the amount of heat contained in the slag, and the slag having the amount of heat is converted into the maximum cooling treatment capacity (J / h) have line control of the introduced into the cooling device 80% to 100% range, as a cooling device for performing secondary cooling, using a rotary cooler with internal means, the inlet side of the rotary cooler, primary A hopper into which the slag after cooling is charged, and a vibration feeder that supplies the slag in the hopper to the rotary cooler while vibrating the hopper, the slag mass in the hopper Determining means and slag temperature measuring means, and the control determines the amount of slag to be cut into the rotary cooler based on the actual measurement data measured by the slag mass measuring means and the slag temperature measuring means, and according to the amount of cut The control is to change the vibration amount of the vibration feeder .

According to a second aspect of the present invention, in the high-temperature slag processing method according to the second aspect, the vibration feeder has a variable control function by an inverter.

According to a third aspect of the present invention, in the high-temperature slag processing method according to the first aspect, the temperature of the slag after the primary cooling is 800 to 1250 ° C.

According to a fourth aspect of the present invention, in the high-temperature slag processing method according to the first aspect, the slag temperature at the outlet of the cooling device is set to 300 ° C. or lower.

The invention according to claim 5 is the high temperature slag treatment method according to claim 1, wherein a grizzly is installed at the inlet of the cooling device to separate the bulk metal in the slag after the primary cooling. Is.

The invention described in claim 6 is the high-temperature slag processing method described in claim 1, wherein the slag containing CaO is steelmaking slag or hot metal pretreatment slag.

In the method for treating high-temperature slag according to the present invention, the mass and internal temperature of the slag after primary cooling are measured before charging the cooling device, the amount of heat contained in the slag is calculated, and the slag having the heat amount is converted into the cooling device. There line control to be introduced into the cooling device 80 to 100% of the maximum cooling capacity of the (J / h), as a cooling device for performing secondary cooling, using a rotary cooler with internal means, said rotary Provided on the inlet side of the cooler is a hopper into which the slag after the primary cooling is charged, and a vibration feeder that supplies the slag in the hopper to the rotary cooler while vibrating the hopper. Measuring means, and the control is based on the actual measurement data measured by the slag mass measuring means and the slag temperature measuring means. Determines the slag cut amount to a control for changing the vibration amount of the vibration feeder in response to the cut-out amount, it has a configuration that will trough. According to this configuration, the amount of heat of the slag that is input into the cooling device is grasped before the input, and the amount of input to the cooling device is determined according to the amount of heat from 80 to the maximum cooling processing capacity (J / h) of the cooling device. Since it can be controlled within the range of 100%, the slag cooling is conventionally compared to the case where the operation is uniformly performed by setting it to about 70% of the maximum slag input amount with the maximum cooling processing capacity of the cooling device. The processing efficiency in the process can be improved.

It is a schematic explanatory drawing of a high temperature slag processing facility. It is explanatory drawing of the slag injection equipment arrange | positioned at the entrance part of a rotary cooler.

Preferred embodiments of the present invention are shown below.
FIG. 1 shows a schematic explanatory diagram of a high-temperature slag treatment facility, and FIG. 2 shows an explanatory diagram of a slag charging facility arranged at the inlet of the rotary cooler.

  In the present embodiment, high-temperature slag is caused to flow down from the slag pan 1 to the pit 2 to perform primary cooling first. The high-temperature slag to be treated in the present invention is steelmaking slag discharged from the furnace or pan or hot metal pretreatment slag, the steelmaking slag is the converter blown slag, the hot metal pretreatment slag is the hot metal dephosphorization slag, hot metal Desulfurization slag, etc. are included.

  In addition, although the temperature of the slag discharged | emitted from a furnace or a pan changes with kinds of slag, generally it is 1400-1600 degreeC in steelmaking slag, and is 1200-1400 degreeC in hot metal pretreatment slag.

  The structure of the pit 2 for performing the primary cooling is not particularly limited, but here, a structure in which a slab having a thickness of 0.25 m is laid on the crushed stone layer is adopted. In addition, primary cooling can also be performed using a cooling box. The hot slag is leveled on the pit 2 to a uniform thickness, and large lumps and bullion are removed. Further, cooling water is sprayed from a watering nozzle (not shown). By this primary cooling, the slag temperature is lowered to about 800 to 1250 ° C.

  Next, slag is taken out from the pit 2 with an appropriate device such as a power shovel, and secondary cooling is performed in the cooling device 10. A hopper 11 is installed in the front stage of the cooling device 10, and a grid 12 for sieving called a grizzly is provided in an inclined state on the surface thereof. The bulk metal in the slag after the primary cooling is separated by the sieving grid 12, and only the small-diameter slag that has passed through the grizzly is put into the cooling device 10 by the vibration feeder 13.

  As shown in FIG. 2, the hopper 11 includes a load cell 17 for measuring the mass of slag thrown into the hopper and a thermocouple 18 for measuring the temperature of the slag thrown into the hopper. Further, the vibration feeder 13 has a variable control function by an inverter, and controls the amount of slag cutout to the rotary cooler.

Specifically, the mass per unit time W (kg / h) and the internal temperature T (K) of the slag charged into the hopper 11 are measured, and the amount of heat Q (J / J) contained in the slag is measured. h) is obtained by the following formula, and the amount of slag cut-out per unit time (t / h) of the vibration feeder 13 so as to be 80 to 100% of the maximum cooling processing capacity (J / h) per unit time of the rotary cooler. Control for determining h) is performed.

  Thus, by grasping the amount of heat of the slag that is input into the cooling device before the input, and controlling the amount of input to the cooling device according to the amount of heat, the processing efficiency in the cooling process of the slag can be improved. it can. For example, when the slag temperature is high, the amount of slag cut out to the cooling device is reduced, and when the slag temperature is low, the amount of slag cut out to the rotary cooler is increased, the maximum cooling processing capacity per unit time (J / H), it is possible to always operate at 80 to 100% of the maximum cooling capacity (J / h) by appropriately increasing or decreasing the amount of slag cutout within a range not exceeding. This makes it possible to treat more slag more efficiently compared to the conventional case where the maximum slag input amount is set to about 70% of the maximum cooling capacity of the cooling device. It becomes.

  Although various types of cooling devices 10 for secondary cooling can be used, a rotary cooler is used in this embodiment. In this case, the casing 14 is rotated around an axis that is slightly inclined with respect to a horizontal plane, and cooling air spraying means is provided therein. The slag that has reached 800 to 1250 ° C. due to the primary cooling is introduced from the hopper 11, fed into the casing 14 by the vibration feeder 13, and gradually moves toward the outlet 15 as the casing 14 rotates. By the secondary cooling, the slag is cooled to 300 ° C. or less, discharged from the outlet 15 to the inclined conveyor 16, and then conveyed to the product pit 20 via the tripper conveyor 19.

DESCRIPTION OF SYMBOLS 1 Slag pan 2 Pit 10 Cooling device 11 Hopper 12 Grid for sieving 13 Vibrating feeder 14 Casing 15 Outlet 16 Inclined conveyor 17 Load cell 18 Thermocouple 19 Tripper conveyor 20 Product pit

Claims (6)

A method for treating high-temperature slag that primarily cools high-temperature slag and then performs secondary cooling while moving inside the cooling device,
The amount of heat contained in the slag is calculated by measuring the mass and internal temperature of the slag after the primary cooling before charging the cooling device, and the slag having the heat amount is converted into the maximum cooling processing capacity (J / h) of the cooling device. There line control to be introduced into the cooling device 80 to 100% of the,
As a cooling device that performs secondary cooling, use a rotary cooler with internal means,
On the inlet side of the rotary cooler, a hopper into which slag after primary cooling is charged, and a vibration feeder that supplies the slag in the hopper to the rotary cooler while vibrating the hopper,
The hopper includes slag mass measuring means and slag temperature measuring means,
Control in which the control determines the amount of slag cutout to the rotary cooler based on the actual measurement data measured by the slag mass measurement means and the slag temperature measurement means, and changes the vibration amount of the vibration feeder according to the cutout amount A method for treating high-temperature slag, wherein: The high temperature slag processing method according to claim 1, wherein the vibration feeder has a variable control function by an inverter . The temperature of the slag which finished primary cooling is 800-1250 degreeC , The processing method of the high temperature slag of Claim 1 characterized by the above-mentioned. The method for treating high-temperature slag according to claim 1, wherein the slag temperature at the outlet of the cooling device is 300 ° C or lower . The processing method of the high temperature slag of Claim 1 which installs a grizzly at the inlet of a cooling device, and isolate | separates the metal bullion in the slag which finished primary cooling . The method for treating high-temperature slag according to claim 1 , wherein the slag containing CaO is steelmaking slag or hot metal pretreatment slag .

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