The smelting methods of high carbon ferrochrome include blast furnace method, electric furnace method, plasma furnace method, melt reduction method, etc. Only special pig iron containing about 30% chromium can be produced in the blast furnace; The plasma furnace method and melt reduction method are new processes for smelting high carbon ferrochrome and have not yet been widely adopted. At present, high carbon chromium iron with high chromium content is mostly smelted in a submerged arc furnace using the flux method. 1、 The basic principle of electric furnace smelting The basic principle of electric furnace smelting high carbon ferrochrome is to reduce chromium and iron oxides in chromium ore with carbon. From the above reactions, it can be seen that the starting temperature for carbon reduction of chromium oxide to produce Cr3C2 is 1373K, the starting temperature for the reaction to produce Cr7C3 is 1403K, and the starting temperature for the reaction to reduce to produce chromium is 1523K. Therefore, during carbon reduction of chromium ore, chromium carbides are obtained, rather than metallic chromium. Therefore, only high carbon chromium iron with high carbon content can be obtained. Moreover, the carbon content in ferrochrome depends on the reaction temperature. It is easier to generate carbides with high carbon content than carbides with low carbon content. In actual production, during the heating process, some chromium ore reacts with coke to form Cr3C2. As the temperature of the furnace material increases, most of the chromium ore reacts with coke to form Cr7C3. The temperature further increases, and chromium trioxide plays a refining and decarbonization role on the alloy. The starting temperature of the reduction reaction of iron oxide is lower than that of the reduction reaction of chromium trioxide. Therefore, the iron oxide in the chromium ore is fully reduced at a lower temperature and dissolves with chromium carbide, forming composite carbides and reducing the melting point of the alloy. Meanwhile, due to the mutual dissolution of chromium and iron, the reduction reaction is easier to carry out. 2、 Smelting process operation of high carbon ferrochrome The production of high carbon ferrochrome using electric furnace flux method adopts a continuous operation method. The raw materials are batched in the order of coke, silica, and chromium ore to facilitate uniform mixing. The open furnace adds the material around the electrode through the feeding groove, and the material surface forms a large cone. The closed furnace directly adds materials into the furnace through the discharge pipe. Whether it is an open furnace or a closed furnace, new materials should be added in a timely manner as the furnace material sinks to maintain a certain level of material height. When the furnace condition is normal, the three-phase current is balanced, the electrodes are stable, the ventilation is good, there is no burning, and the furnace material can sink evenly; The temperature of slag and iron is normal, the composition of alloy and slag is stable, and can be smoothly discharged from the furnace; The furnace pressure of a fully enclosed furnace is stable, and the amount and composition of furnace gas do not change much. There is no explosion in the material tube when the raw materials are dry. The number of iron tapping is determined by the capacity of the electric furnace, and iron and slag are simultaneously discharged from the tapping port. In the later stage of iron production and when slag production is not smooth, round steel should be used to clear the furnace hole to help with slag discharge. Determine the depth of blockage based on the degree of erosion of the furnace lining. Carbon brick lining is blocked with refractory clay balls, while magnesium brick lining is blocked with a certain proportion of magnesium sand powder and refractory clay balls. The characteristics of abnormal furnace conditions are: 1. When the amount of reducing agent is insufficient, the electrode is inserted deeply, the current fluctuates, the load is insufficient, and the electrode is consumed quickly; The flame at the furnace mouth darkens; The alloy has low silicon and carbon content, hard iron, and many skin bubbles. The content of Cr3C2 in the slag increases, and the viscosity of the slag increases. 2. When there is an excess of reducing agent, the electrode is inserted shallowly, the current fluctuates, sparks, slag sprays, and the electrode consumption is slow; The temperature at the bottom of the furnace is low, making it difficult to open the tapping hole and discharge the slag; The content of carbon and silicon in the alloy increases, while the content of Cr3C2 in the slag decreases. 3. When there is too much silica, the electrode is deeply inserted, the flame becomes dark, the fluidity of the slag is good, the content of Cr3C2 in the slag increases, the solidified slag turns black, the furnace wall is severely corroded, the carbon content in the alloy increases, the superheat of the alloy is small, and it is difficult to discharge from the furnace. 4. When there is too little silica, the electrode is inserted shallowly, the furnace temperature is high, and there is thick slag around the electrode, which is easy to flip. The viscosity of the slag is high, making it difficult to release from the furnace. Due to the high furnace temperature, the temperature of the molten iron is high, the carbon content decreases, and the amount of slag and iron is also small. 5. When the amount of silica and coke is insufficient, the content of Cr3C2 in the slag is low, very viscous, containing many unreduced chromite and small metal particles, which are difficult to flow out of the furnace. The content of silicon and carbon in the alloy decreases. 6. When the amount of coke is insufficient and the amount of silica is excessive, the slag temperature is low, easy to melt and viscous, containing a large amount of silicon dioxide, Cr3C2, and iron oxide. The silicon content in the alloy decreases and the carbon content increases; Insertion depth under the electrode increases consumption. 7. When there is an excess of silica and coke, the slag is easily melted, and some coke with hanging slag is discharged from the tapping hole; The silicon and carbon content in the alloy are both high; Unstable insertion of electrodes. 8. When there is excess coke and insufficient silica, the electrode is lifted up, causing a stinging fire, and coke sprays out from the crucible; The melting point of slag is high, the temperature of slag is also high, the content of Cr3C2 in slag is low, the slag is viscous, and it is not easy to release from the furnace. The chromium content in the alloy depends on the chromium iron ratio in the chromium ore and the recovery rate of chromium. The carbon content in alloys is mainly related to the physical properties of chromium ore. When chromium ore has good melting ability and small block size, the feeding rate is fast, the furnace temperature is low, and the carbon content of the alloy is high; On the contrary, if the ore is difficult to melt, has a large block size, slow feeding speed, and high furnace temperature, due to the refining effect of Cr3C2 on chromium carbides in the block ore, the carbon content of the alloy is low. The silicon content in the alloy is mainly related to the amount of reducing agent used, the silicon dioxide content in the slag, and the furnace temperature. If the amount of reducing agent is high, the furnace temperature is high, and the silicon dioxide content in the slag is relatively high, the silicon content in the alloy is also high; On the contrary, the silicon content in the alloy is low. The silicon content of the alloy fluctuates between 0.1% and 5% during production. About 80% of the sulfur in the alloy comes from coke, so to reduce the sulfur content of the alloy, low sulfur coke must be used. In the smelting process of high carbon ferrochrome, the amount of flux directly affects the composition of the slag. Due to the fact that the composition of slag determines its melting point, which in turn determines the temperature inside the furnace, selecting and controlling the composition of slag is an important issue in smelting ferrochrome. The appropriate composition of slag can reach a sufficient temperature inside the furnace, ensuring the smooth progress of reduction reaction and the smooth discharge of reduction products. The melting point of high carbon ferrochrome is over 1773K. In order to ensure a high reaction rate and facilitate the smooth release of the generated alloy from the furnace and separation of slag and iron, the furnace temperature must be controlled above the melting point of ferrochrome at 1923-1973K. Therefore, the melting point of slag should be controlled within this range. Otherwise, if the melting point of the slag is low and the temperature inside the furnace is also low, although the slag can flow out smoothly during the discharge, the molten iron cannot flow smoothly due to the low superheat, resulting in a phenomenon of more slag and less iron, and in severe cases, only slag but not iron will be discharged; If the melting point of slag is too high and the temperature inside the furnace is also high, the slag cannot flow smoothly due to the high melting point and insufficient superheat. However, if the molten iron can flow smoothly, there will be a phenomenon of less slag and more iron, and in severe cases, only iron will be produced without slag. After the reduction of Cr3C2 and FeO in chromite, the remaining main oxides are magnesium oxide and aluminum trioxide. Both of these oxides have high melting points and require the addition of a flux (silica) to lower their melting points before they can flow out of the furnace. Therefore, the amount of flux directly affects the composition of the slag. The amount of silica added is determined based on the aluminum magnesium silicon ternary phase diagram. Due to the ratio of magnesium oxide to aluminum trioxide in the slag being around 1, it is possible to draw a line perpendicular to the bottom through the vertex of silicon dioxide. The points on the line represent the melting point of the slag, which decreases with the increase of silicon dioxide content. When the ratio of magnesium oxide to aluminum trioxide changes, it has little effect on the melting point of the slag, because the isomelting line is basically parallel to the bottom line. When checking the ternary phase diagram, the sum of the contents of silicon dioxide, aluminum trioxide, and magnesium oxide in the slag must be converted to 100%. The content of alumina in slag has an impact on the viscosity of the slag. If the content of alumina in slag is too high, the viscosity of the slag will increase, which is not conducive to slag discharge. But aluminum trioxide can increase the resistivity of the slag, which is beneficial for deep electrode insertion, so a certain amount is required.

In the modern large and medium-sized steel casting production enterprises, the electric energy consumption per ton of molten steel in the electric arc furnace is an important energy index. Now we have the experience in the production of 30t electric arc furnace in our company's cast steel business unit, and talk about the relationship between electric arc furnace fabric and power transmission system. The original cloth method of Harbin Electric Machinery Co., Ltd. simply stipulates that the heavy material is added to the bottom and the upper part is light and thin; the power transmission system is for 5~10min for small current and low voltage, and the highest voltage and maximum after the arc is buried in the scrap. The current is sent and melted, and the oxygen is cut in the middle. After the collapse is completed, the reactor is removed, and the three-stage voltage is supplied, and the current is appropriately adjusted according to the smelting condition. After the energy management refinement and upgrading, we found that the same material, the same tonnage of smelting furnaces, different time, different power consumption, statistical analysis found that the same charge, the maximum power transmission, the whole furnace for the steel sheet furnace The average average smelting speed is obviously faster than the average melting speed of most risers plus a small amount of waste steel sheet heat, and the uniform melting rate of the charge is faster than that of the furnace. Most of the charge is a riser, with an average power consumption of 20%. Several comparison tests were conducted for the number of heats that were loaded into large risers. The first group is the highest voltage and maximum current after penetrating the well. The second group is the voltage drop to 2 after the well, the current is reduced by 20%, the melting rate is not significantly different, and the second group of power consumption is reduced by 5% to 10%. . Our analysis believes that the melting rate of the large riser and the edge of the charge is slow, the power supply is too fast and can not be absorbed quickly, local high temperature, large heat dissipation, resulting in increased power consumption. The adjustment measures are as follows: the feeding material is as stable and uniform as possible, so that the charging material, especially the heavy material, is not biased toward the edge of the furnace body; when the material block is too large, the power supply strength is appropriately reduced. In the case where the same tonnage, the same furnace charging method and the power transmission mode have appeared in the test, the smelting time is also similar, but the power consumption varies greatly. The maximum energy consumption is 15%. According to the voltage and current loaded into the electric furnace, we calculate the electric energy input into the electric furnace, and find that the electric energy used for melting is basically similar. The difference is that the working time of the reactor is different, because the reactor consumes a part of electric energy, resulting in an increase in reactive power. , resulting in an increase in electricity consumption per ton of molten steel. After a period of statistics, the energy consumption of the furnace with a long period of time is too large. Through reasonable cloth and oxygen blowing, it is possible to advance the time of leaving the reactor and reduce the power consumption of smelting. The power transmission system of the electric furnace is a main working system used by the electric arc furnace. It should not be static. It should be adjusted according to the specific conditions of the charging materials. The fabric is a basic work and should be strictly according to the smelting characteristics of the electric arc furnace. Prescribe and refine operations.  

According to relevant national and regional policies, from now on, the city will restrict the production of calcium carbide and ferroalloy. In order to conscientiously implement the State Council's video and telephone conference on energy conservation and emission reduction work and the “State Council’s Circular on Further Enlarging Work to Ensure the Implementation of the “Eleventh Five-Year Plan” Energy Conservation and Emission Reduction Targets”, the Autonomous Region Government issued the “Inner Mongolia People’s Government’s Implementation Guarantee” a few days ago. After completing the "Eleventh Five-Year Plan" emergency measures for energy saving targets, it was decided to limit the production of calcium carbide and ferroalloy, and the output of calcium carbide and ferroalloy allocated to our city was 1 million tons and 190,000 tons, respectively. In order to ensure the completion of the “Eleventh Five-Year Plan” energy saving target, strictly implement the plan for production distribution of calcium carbide and ferroalloy in the autonomous region, and according to the needs of the energy conservation situation, the city decided to implement restrictions on production or production suspension of calcium carbide and ferroalloys so as to curb the rapid growth of calcium carbide and ferroalloy. . From now on, all ferrosilicon enterprises in the city's ferroalloy industry will stop production, the remaining production will be allocated to ferromanganese, ferrochrome, nickel-iron and other enterprises; calcium carbide will be allocated to calcium carbide as much as possible by quotas, the integrated upstream and downstream PVC group.

The vertical aluminum alloy quenching furnace is a cycle-type resistance furnace, which is mainly used for the heating of quenched aluminum alloy parts. The vertical aluminum alloy quenching furnace has the advantages of uniform furnace temperature, rapid temperature rise, short water inlet time, and low energy consumption. The temperature control system of the vertical aluminum alloy quenching furnace adopts PID zero-triggered thyristor, and the structure of the electric furnace consists of bottom bracket, heating furnace body, heating element, hot air circulation system, mobile quenching tank truck, basket lifting mechanism, control system, etc. Partly composed. Brief introduction of vertical aluminum alloy quenching furnace: The vertical aluminum alloy quenching furnace consists of a heating furnace cover and a mobile chassis. The square (or round) furnace hood is equipped with a crane, and the basket can be hoisted to the furnace through chains and hooks. The furnace hood is supported by a profiled steel and the bottom of the oven door is operated pneumatically (or electrically). The base frame below the furnace hood can be moved along the track and positioned. The chassis carries the quenched water tank and basket. Vertical aluminum alloy quenching furnace features: (1) Temperature uniformity of vertical aluminum alloy quenching furnace The temperature uniformity achieved by the user is guaranteed by the associative design of the circulation fan, wind deflector plate, furnace structure, electric power distribution, arrangement of electric heating elements, control method and process, and door structure. (2) Vertical aluminum alloy quenching furnace with advanced mechanical system The advanced nature of the system is ensured by the design, component selection and quality, and processing and manufacturing quality. The mechanical system runs smoothly and reliably, and the equipment is in a state of low noise and low vibration. (3)Vertical aluminum alloy quenching furnace has perfect control system Reflected in 100 - 650 °C can achieve accurate temperature control, the system is stable and reliable, easy to operate, to avoid human error operation, complete functions and so on. (4) Quenching transfer time is rapid and adjustable Bottom-moving furnace door, rapid lifting mechanism, and advanced mechanical system make the quenching transfer fast and reliable. The time can be based on the user's process requirements, quenching speed ≤15S. (5) The quenching tank adopts a mobile trolley, or adopts the form of a pit, so that the workpiece can be processed conveniently and quickly.