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Several key issues for improving the production efficiency of calcium carbide furnaces (including open furnaces): 1. The quality of lime. The over-burning quality of lime affects the electricity consumption and production of calcium carbide, with little impact on the long-term operation of calcium carbide furnaces. Magnesium in impurities has a significant impact on calcium carbide production; it affects both yield and quality. Sticky calcium carbide and high temperatures resulting from magnesium oxidation not only prevent the electrodes from functioning properly but can also cause damage to the electrodes and the equipment in the furnace. Therefore, the magnesium content in lime must be strictly controlled. It can be said that lime with a high magnesium content is not suitable for producing calcium carbide, and it is impossible to achieve good results in calcium carbide production. 2. Quality issues with coke. The impurities in coke have a modest impact on the power consumption and yield in calcium carbide production. Carbon materials with low fixed carbon content can affect the quality of calcium carbide; however, by adjusting the proportions used, it is possible to produce high-quality calcium carbide. This adjustment does have an effect on power consumption, but it is not a decisive factor in the production process. The high resistance of carbon materials is the most important factor in carbon materials. The depth to which the electrodes penetrate into the furnace is the most important issue in calcium carbide production; it is the key factor that determines the success of the entire production process. Therefore, reducing the particle size of coke and using carbon materials with high electrical resistance (such as lignite, anthracite, oil coke, etc.) are issues that should be given great attention in calcium carbide production. 3. The proportional relationship between the particle sizes of lime and coke. Generally, in calcium carbide furnaces, the particle size of lime is controlled between 5–40 mm, while that of metallurgical coke is kept below 20 mm; this allows the resistance of the furnace charge to meet the requirements for high production and high quality. Of course, further narrowing the control range of the particle size is more beneficial for calcium carbide production, but it will increase the cost of raw materials. 4. Ensure the pressing depth of the electrode, so that it extends at least 1.2 times the diameter of the electrode into the furnace. It should be noted that to accurately assess the quality of electrode baking, when the current is at its maximum and the load is high, the baking process proceeds relatively quickly. In such cases, it is possible to apply pressure multiple times – by increasing the number of applications but using smaller amounts of pressure each time – which can accelerate the baking process of the electrodes. 5. The three-phase molten pool must remain unobstructed. The three-phase molten pool remains unobstructed, which facilitates the timely removal of calcium carbide; this prevents situations where certain phases of calcium carbide fail to be removed and the electrodes do not descend, thus avoiding the vicious cycle that is most undesirable in calcium carbide production. To maintain three-phase connectivity, attention must be paid to three aspects. First, the resistance of the furnace charge must be high; therefore, carbon materials with high resistance (including particle size) should be selected. Second, the depth of penetration of the control electrode. Generally speaking, when starting the furnace, the transformer is connected in a Y configuration; or production is carried out at low load with high current and low voltage, which allows for the forced insertion of electrodes to rapidly raise the temperature inside the furnace, thereby facilitating smooth operation of the three phases. Once the three conditions for starting a new furnace are met, the load can be increased at an appropriate time; the necessary electrode length can be maintained or even increased to sustain a stable operating condition in the furnace. Once all three are operational, maintain high-load operation. Third, manage the relationship between furnace exit and electrode stability. Calcium carbide in the molten pool generally has a negative effect on the penetration of the electrode; removing the calcium carbide promptly allows the electrode to penetrate further, and this deeper penetration in turn facilitates the removal of calcium carbide, creating a positive feedback loop. Under normal circumstances, if the electrodes do not descend or if the operating current is high, it is necessary to consider removing the furnace contents promptly. The position of the furnace opening should always be kept low, so that the bottom of the furnace remains at a lower level; this helps the electrodes to remain stable and deeply inserted in the furnace for an extended period, and it also facilitates the timely removal of ferrosilicon, thereby extending the furnace’s service life.