Large-furnace high-voltage low-current industrial silicon smelting process

Abstract

The invention relates to the technical field of submerged arc furnaces for industrial silicon, in particular to a large-furnace type high-voltage and low-current industrial silicon smelting process. The method comprises the following steps of: producing industrial silicon in a 33000KVA industrial silicon electric furnace by adopting high voltage and low current; the 33000KVA submerged arc furnace adopts high voltage and low current to produce industrial silicon, and the secondary voltage of the industrial silicon electric furnace reaches 240V or above. Compared with the prior art, the method has the advantages that the furnace condition fluctuation is small, the smelting period is long, the unit power consumption is low, the power consumption and the production cost are greatly reduced, and a solid foundation is laid for subsequent automation and intellectualization.

Description

Technical Field

[0001] The invention relates to the technical field of ore-fired furnaces for industrial silicon, and is a large-furnace high-voltage, low-current smelting process for industrial silicon. Background Art

[0002] The carbides and slag generated during the production of silicon are deposited at the bottom of the furnace, causing the bottom of the furnace to rise, the electrodes to lift, difficulty in unloading, ignition on the surface of the material, short simmering time, high unit energy consumption, etc. If the furnace condition is not discovered early, correctly analyzed and judged, and effective measures are not taken in time, it will eventually lead to economic losses such as stopping the furnace, digging the furnace, building the furnace, and starting a new furnace.

[0003] In recent years, with the influence of national macro policies and the increase in enterprise production capacity, industrial silicon electric furnace equipment has developed in the direction of large-scale, automated and environmentally friendly. However, large-scale and automated industrial silicon electric furnaces cause frequent fluctuations in furnace conditions, easy rise in furnace bottom temperature, and a short effective smelting cycle, which not only results in poor production indicators and high unit power consumption, but also leads to a substantial increase in comprehensive costs such as furnace shutdown, furnace digging, furnace building, and new furnace opening. Summary of the invention

[0004] The present invention provides a large-furnace high-voltage, low-current smelting industrial silicon process, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of frequent furnace condition fluctuations, short smelting cycle, high unit power consumption and high production cost of existing industrial silicon electric furnaces.

[0005] The technical solution of the present invention is achieved through the following measures: a large furnace high voltage, low current smelting industrial silicon process, according to the following method: 33000KVA industrial silicon electric furnace adopts high voltage, low current to produce industrial silicon.

[0006] The following are further optimizations and / or improvements to the above technical solutions: The above secondary voltage is 243V to 253V.

[0007] The above primary current is 443A to 530A.

[0008] The 33000KVA ore-fired furnace of the present invention adopts high voltage and low current to produce industrial silicon, and the secondary voltage of the industrial silicon electric furnace reaches above 240V. Compared with the prior art, the present invention has less furnace condition fluctuation, longer smelting cycle and lower unit power consumption, which greatly reduces power consumption and production cost and lays a solid foundation for subsequent automation and intelligence. Implementation

[0009] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0010] Example 1: The large furnace high voltage, low current smelting industrial silicon process is carried out according to the following method: A 33000KVA industrial silicon electric furnace adopts high voltage and low current to produce industrial silicon.

[0011] Embodiment 2, as an optimization of the above embodiment, the secondary voltage is 243V to 253V.

[0012] Embodiment 3, as an optimization of the above embodiment, the primary current is 443A to 530A.

[0013] The invention discloses a large furnace high voltage, low current smelting process for industrial silicon, and the technical problems to be solved and the determination of the technical solutions (1) One of the core factors of smelting in a submerged arc furnace (industrial silicon electric furnace) is the electrode power. The submerged arc furnace uses arc and heat mixed work, that is, star and angle mixed work. The result is that under different capacities and a certain smelting voltage, the arc does not do work, only the heat resistance does work. Because the arc pressure on the electrode head is low and the arc cannot be started, the greater the heat resistance, the smaller the arc heat, which is a nonlinear relationship.

[0014] (2) Add material barriers to cut off branch current and increase secondary voltage.

[0015] (3) Find the differences: Compare the experimental results, find the differences in the production conditions of the same furnace type with different voltages and currents, and make improvements.

[0016] Faced with huge market pressure, the company urgently needs to rely on the resources and technology of the group company, combined with the conditions of existing equipment, to invest in the research and development of high-voltage and low-current production of industrial silicon; so as to achieve high and stable production and the expected hot shutdown period of up to one month without dry burning treatment.

[0017] Technical solution of the present invention: (1) Finding data difference points Analyze and study the various parameters of furnaces of different companies (secondary voltage, primary current, electrode voltage, electrode resistance, active power, reactive power, power factor, transformer gear and other production parameters), find out the differences and make improvements.

[0018] (2) Comparative analysis and experiment By comparing with the 12500KVA, 2 and 25500KVA used by the group's brother company (Xinjiang Western Silicon Materials), on this premise, we used our company's 33000KVA to conduct experiments of different degrees to determine the secondary voltage and primary current to be used in the end. This experimental project is the first 33000KVA industrial silicon furnace in the country to produce at high voltage and low current, laying a solid foundation for subsequent automation and intelligence.

[0019] The company's equipment is used to maximize the secondary voltage of the 33000KVA ore-fired furnace and reduce the primary current parameters for production. Compared with other artificially controlled industrial silicon ore-fired furnace smelting processes in China, not only is the furnace operation more stable (small current and voltage fluctuations, greatly reduced electrode operation, wide and uniform ignition area on the material surface, and timely handling of abnormal situations), but also has outstanding advantages in terms of power consumption.

[0020] The occurrence of dry burning during hot shutdown is reduced, and the furnace that has been hot shut down for up to one month does not need to be dry burned, and each furnace eye can be boiled normally; it takes an average of about 9 days to resume normal production (daily output of more than 46 tons).

[0021] (1) Secondary voltage range: 243V-253V (2) Current range: 443A-530A (3) Active power range: 26000KW-29000KW (4) To avoid causing the furnace bottom to rise, the electrode to move upward, the furnace eye to be blocked, the output to decrease, and the cost to increase, dry burning treatment should be carried out.

[0022] The secondary voltage is selected from 243V to 253V. The furnace that has been shut down for up to 29 days does not need to be dry-burned. Each furnace eye can be boiled normally, and normal production can be restored in an average of about 9 days (daily output of more than 46 tons). This experimental project is the first 33000KVA industrial silicon electric furnace in the country with a secondary voltage of more than 240V, laying a solid foundation for subsequent automation and intelligence.

[0023] Advantages of the present invention: Economic Benefits (1) Energy saving: The automatic control system can effectively adjust the balance of power consumption inside the industrial silicon furnace. Compared with the period before the technical transformation, it saves 1,000 kWh of electricity per ton of silicon on average. Calculated at 0.39 yuan per kWh, it saves 390 yuan per ton of silicon. Calculated at an annual design capacity of 400,000 tons, it saves 156 million yuan per year.

[0024] (2) Saving raw material costs: The use of automated control systems reduces direct material costs by RMB 326 per ton. Based on an annual design capacity of 400,000 tons, this results in an annual cost savings of RMB 130.4 million.

[0025] Social Benefits (1) Promote the economic development of Shanshan; encourage more skilled talents from secondary vocational schools, colleges and other institutions to find employment, promote social progress, stimulate employment and improve people’s living standards.

[0026] (2) The use of high voltage and low current has outstanding advantages in energy saving and consumption reduction, saving 1,000 kWh / ton of electricity, saving 40 million kWh of electricity per year, optimizing energy use, and playing a positive role in environmental protection and energy conservation.

[0027] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A large furnace type high voltage, low current smelting industrial silicon process, characterized in that Proceed as follows: 33000KVA industrial silicon electric furnace uses high voltage and low current to produce industrial silicon.

2. The large furnace high voltage, low current smelting industrial silicon process according to claim 1 is characterized in that The secondary voltage is 243V to 253V.

3. The large furnace high voltage, low current smelting industrial silicon process according to claim 1 or 2, characterized in that The primary current is 443A to 530A.