1. Horizontal converter blowing example

The table below lists the equipment, operating conditions and product composition of horizontal converters for some nickel plants at home and abroad.

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2. Normal operation of horizontal converter blowing The normal operation of the furnace production includes feeding, opening air, adding flux, adding cold material, and discharging slag. This is repeated several times until the furnace capacity is reached, and then concentrated into a high-nickel crucible. .
For the first feeding, two packs of low nickel crucible are generally added, about 30t, and the furnace is transferred to the blowing position for air softening. When turning the furnace, care should be taken to open the air before the tuyere is immersed in the melt to prevent the tuyere from being filled. At the beginning of the air blowing for ten minutes, the purpose is to oxidize and volatilize impurities such as lead and zinc in the nickel crucible. At this time, the exothermic reaction in the furnace can raise the furnace temperature quickly. When the temperature of the furnace rises to 1200 °C ~ 1250 °C, it is possible to add cold material and quartz for the slag-forming cold material and quartz to be staggered and added in batches, each time adding about 4t. The principle of adding quartz and cold materials: diligently, less, and evenly added to ensure proper furnace temperature and good slag type.
The practice of blowing production shows that the amount of quartz added to the furnace has a great influence on the slag type. When the quartz in the furnace is used for a long time, the slag is sticky and the fluidity is poor. Some of the slag entrained with quartz particles adheres to the furnace wall; the crust is placed on the inner surface of the slag package; the flame is blue-white during blowing. The normal amount of quartz and the good slag type are as follows: the deep liquid level swings back and forth, the slag is placed on the inner surface of the package, and the crust is hollow, and the slag is hollow and spherical, and the flame is slightly blue.
It takes about 55 minutes from the feeding to the first package of slag. The performance of the slag is: the flame is clear and the bluish is blue, and the splash is bright. After the residue was added to a bag made good low nickel matte, blowing 3 ~ 5min and then put a pool, on which mesh Chang reduced slag containing copper, cobalt and other valuable metals. The prepared slag is placed in a 6m3 cast steel ladle brushed with yellow mud water. When the thickness of the slag layer in the furnace is 20~30mm, the slag is stopped to avoid releasing nickel ruthenium. When slag is discharged, the thickness of the slag should be measured by the slag hook. The amount of slag is generally one package at a time. When slag is discharged, the amount of quartz in the furnace and the slag type should be observed.
After the slag is discharged, the furnace is transferred to the feeding position, a package of low-nickel bismuth is added, the furnace is blown open, and the quartz slag is added in batches, and the cold material is added to control the temperature of the furnace, so that the melt is repeated until the slag is melted. accounting for feeding was stopped when 1/3 ~ 1/2 volume of the bath when the furnace iron nickel matte containing 8% to 10% of the furnace operation can be carried out screen.
In the sieve furnace, the thickness of the slag layer is only about 20 mm. The shorter the operation time of the sieve furnace, the higher the metal recovery rate and the larger the output. The amount of quartz added can be appropriately increased in the sieve furnace to accelerate the slagging. The furnace body should be gradually inclined backward during the sieve furnace, usually 10-15 min. Rotate once, each time about 100mm. When the blowing flame is cleared by mixing, the smoke is obviously reduced, and when the flame appears green, the blowing is nearing the end point, and the nickel-containing iron is close to 2% to 4%. At this time, the furnace can be considered, and then the furnace is added. Some quartz is blown for about 2 minutes, and the slag is discharged by rotating the furnace. The sample is quickly analyzed. If the iron is qualified, it can be discharged. The iron content of the sample needs to be judged by the operator's intuitive observation of the sample. The visual observation method of whether the sample is qualified is: the performance of the qualified sample is good, the conductivity is good, and the surface tension is large. Because of the different physical shapes of the sample on the sample plate, the qualified section has a narrower, thicker surface with a certain oily luster and wrinkles. When the heat is opened, the cross section is golden yellow when the temperature is high, and dark red when the temperature is low. When the temperature is low, the grain is fine and the grain is fine and silvery white. The unqualified sample with high iron content has a thin section, the surface is dark and has burrs, the heat is broken, the central part is dark, the cold section is rough, the iron content is less than 2%, and the cross section is narrower. Thicker, the hot-opened section of golden yellow quickly turns dark red, the surface is tarnished, spots begin to appear, metal performance is stronger, but the yield is significantly reduced. After the melt is high nickel bismuth, it is poured into the cast steel slag, and then suspended by a crane to a high nickel crater for casting.
The bag is poured into the slag package which is cleaned and brushed with yellow mud water. After being placed for 3 hours, the slag is poured out, and a slag shell is formed on the inner side of the bun. Since the melting point of the slag is about 200 ° C higher than that of the high nickel niobium, and the thermal conductivity is not good, the buns can be protected from the nickel crucible. [next]
3, horizontal converter blowing fault treatment production practice often has blowing temperature too low, too high, slag over blowing, excessive and too little quartz flux, leakage furnace and other failures, must take measures to restore normal operation .
(1) The furnace is too low. It means that the furnace temperature is lower than 1000 °C, and the reaction speed in the melt in the furnace is slow. The performance is as follows: 1 wind pressure increases, hurricane occurs; 2 flame reds and sways weak; 3 hurricane mouth is difficult, steel brazing is sticky There are many knots, the reasons are: 1 the furnace temperature before the feed is too low, the quartz and cold materials are added too much; 2 the low ice nickel with too much slag; 3 the furnace remains too much to repair the residual fire Material; 4 due to the temperature of the low tuyere bonding is severe, the air supply is difficult to react slowly.
Treatment method: 1 increase the air supply capacity, that is, organize the manpower, strengthen the air supply, and speed up the reaction; 2, contact with the previous process, enter a package of hot nickel crucible, increase the melt temperature; 3 pour out part of the cold melt Body, plus some hot nickel to stay. Generally, after taking the above measures, a pack of slag is produced and the furnace temperature can be restored to normal.
(2) The furnace temperature is too high. The melt temperature exceeded 1300 °C. Its performance is as follows: the flame is in an incandescent state, the wind pressure is small, the air volume is greatly turned over the furnace to see the lining bright and dazzling, the brick joint is obvious, the slag has good fluidity, and like the water, there is no need for a hurricane.
Treatment method: Add quartz and cold materials properly to reduce the furnace temperature to normal, or directly release the superheated slag. The reaction in the furnace is also a cause of high temperature, which can reduce the supply of air to reduce the reaction speed. When it is impossible to add quartz or cold material, turn the furnace to cool naturally.
(3) The foreign minister blew over. The end point of the furnace was not controlled, and the iron content of the high nickel niobium was reduced to less than 2%. The loss of copper and nickel increases during over-blowing, a portion of the over-blowed copper, nickel oxide and silica slag, and the other part adheres to the lining, resulting in a significant reduction in production.
Treatment method: Slowly add a small amount of low nickel niobium to the furnace before slag to reduce, which can reduce the loss of valuable metals.
(4) The slag is over-blowing. After the slag is built, it is not released in time and the slag is blown. The performance is as follows: the slag splashes frequently, and when the blow is heavy, a small amount of slag is sprayed first, followed by a large amount of spray, or even all of it. The slag that has been blown is in the form of a sheet, which is grayish white after cooling; the slag is sticky when slag is discharged, the fluidity is poor, and the slag shell is thick. The main hazard of slag over-blowing is that the acidity of the slag increases, the lining erosion is severe, and the slag contains metal.
Treatment method: first put less slag, then put in low nickel bismuth or wood, scrap iron and other reducing substances for reduction and blowing and appropriately reduce the amount of quartz added, and slag is released after about 15 minutes of blowing.
(5) Too much or too little quartz. Mainly refers to the content of silica in the slag, less silica, easy to form magnetic iron oxide, resulting in operational difficulties, while increasing the loss of nickel and cobalt in the slag. At this time, it is necessary to add less, add quartz, and gradually reduce the magnetic iron oxide to ferrous oxide to form slag. Excessive silica will increase, and care should be taken to reduce the amount of quartz added.
(6) Air outlet area, end wall, furnace venting. It means that the melt leaks from the tuyere area, the end wall and the outside of the abdomen.
Treatment method: light watering is cooled and blocked with yellow mud; when it is severe, the melt is poured out to prevent burning of the furnace shell, and then continue to blow after processing.
(7) Suddenly stop the wind, power off, and stop the water. When the wind is suddenly stopped or the power is cut off, the automatic protection device of the furnace will automatically turn the furnace to the feeding position to stop. However, when the automatic protection device of the converter fails, the standby power supply should be started immediately. The converter is stopped at the feeding position to prevent the tuyere from being filled. Even if the automatic protection device is good, it should be monitored at any time to prevent accidents. When the water is stopped, the furnace should be turned to the same material position to prevent the water-cooled hood from being burnt out.

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