SU885758A1 - Method of stabilizing shaft furnace heat condition - Google Patents

Description

I

The invention relates to metallurgy and can be used in the reduction-sulphidizing shaft smelting of briquetted ore using coke as fuel and with an air-blowing tuyere stock.

There is a known method of stabilizing the thermal condition of a shaft furnace with an evaporative cooling unit, which includes periodic monitoring of the level of rash, measurement and continuous comparison and change in pressure and flow rate to blow Ij.

The disadvantages of the known method are that in the shaft furnaces for reducing sulphiding nickel ore smelting with high rates of discharge of charge materials, it is difficult to stabilize the level of rash, with a decrease in which the temperature of the flue gases rises, resulting in a decrease in the resistance of the evaporative cooling unit and the residence time in the shaft furnace of charge materials is reduced, as a result of which the completion of the mass-exchange processes of the ore-reduction of ore is reduced and the loss of metal with slag.

The purpose of the invention is to increase the resistance of the evaporative cooling unit and reduce the loss of metal from the slag.

The goal is achieved by the fact that in the well-known method of stabilizing the thermal conditions of a shaft furnace with evaporation cooling settling for a sulphidation reduction smelting of briquetted nickel ore, including periodic monitoring of the level of rash, definition, continuous comparison and pressure variation, blow when the level of rash decreases below

10 optimal specific consumption blowing on 1 m of charge materials is maintained constant and equal to its specific consumption at the optimum layer height in the shaft furnace.

The method is carried out as follows.

Continuous comparison of the hydraulic resistance of the column of charge materials and the flow rate to blow on the mine smelting process allows us to constantly monitor the volume of charge materials (rash level) in

20 shaft furnace and when it is lowered to regulate the specific flow rate to blow on M m of charge materials. ,

The fact that the optimum specific flow rate blows when the level of rash is lowered helps to stabilize the thermal condition of the shaft furnace at the optimal level and to avoid both overheating and cooling of the shaft furnace, while reducing its full volume allows it to avoid further reduction of the rash level.

Example. FIG. I shows the change in the hydraulic resistance of the column of charge materials (pressure to blow, LR) air flow to blow (V), gas temperature at the outlet of the furnace top (t), depending on the level of rash (DN) in the usual and proposed method of operation of the shaft furnace, and FIG. 2 - the change in the specific consumption of blowing on I m of charge materials (V) also with the usual and proposed method of operation of the shaft furnace.

The level of rash was determined by direct measurements by the standard method. Depending on the level of rash in the shaft furnace, according to the indications of stationary measuring instruments, the pressure is recorded to blow (curve I, fig. 1, L), its flow (curve 2, fig. 1 B) and the gas temperature at the exit of the furnace top (curve 3, Fig. 1 D) in the usual mode of a shaft furnace. The specific consumption of blowing for 1 m of charge depending on the level of rash during this mode of operation (curve 4) is presented in FIG. 2. A change in the specific consumption of the charge on the I m of the charge during fluctuations in the level of rash causes changes in the thermal state of the shaft furnace.

To stabilize the thermal state of the shaft furnace, the specific air flow rate is blown for 1 m of the charge at the optimum level of rash, which is kept constant (curve 5, fig. 2) when the level of rash falls below the optimum level. This is achieved by changing the position of the throttle valve in the air blowing path, depending on its pressure. For a constant specific flow rate, the pressure adjustment curves for blowing (curve 6, fig. I, A) are determined depending on the level of rash and the flow (blowing), curve (7, figs. 1, 5). A change in the temperature of the gases leaving the furnace top with the proposed method (curve 7) is shown in FIG. I, A.

A comparison of the conventional and the proposed method of operating a shaft furnace for a sulphidizing reducing furnace of briquetted nickel ore makes it possible to establish that using the proposed method makes it possible to increase the resistance of the evaporative cooling unit, reduce the loss of nickel with slag, reduce coke consumption, eliminate the formation of channels and funnels through which blows most of the time, reduce the dust from the furnace.

Claims (1)

Invention Formula A method for stabilizing the thermal condition of a shaft furnace with an evaporative cooling unit for reducing sulphidizing smelting of briquetted nickel ore, including periodic monitoring of the level of rash, measurement, continuous comparison and pressure change blowing, because in order to increase the durability of the evaporative cooling system and reduce metal losses with slag, when the level of rash falls below the optimum, the specific flow rate to blow on I m of charge materials is kept constant and equal to its specific Mu consumption at the optimum layer height in the shaft furnace. Information sources, taken into account in the examination 1. The patent of the NDP No. 85344, cl. F27 B 1 / S, 1976. -g -If -Iff -12 -Iff -o, e -0.1 -o, g o, o & Nashy, n fig. 2