Silicon thermal reduction smelting equipment

April 01, 2024

Production of silicon thermal reduction method rare earth ferrosilicon alloy iron smelting device, usually borrow EAF and standard equipment. The overall requirement for the equipment is to adapt to different raw materials to produce a variety of products, save energy, have a high degree of mechanization and automation, high production efficiency, long service life, easy maintenance and environmental protection. The main technical parameters of domestic common arc furnaces for smelting rare earth ferrosilicon alloys are listed in Table 1.

Table 1 main technical parameters of electric arc furnace

model	HGT-0.5	HGX-1.5	HGX-3	HGX-5
Electric arc furnace capacity / t Transformer capacity / kVA Shell diameter / mm Furnace diameter / mm Molten pool diameter / mm Electrode diameter / mm Maximum electrode travel / mm	0.5 500 1480 950 240 150 850	1.5 1200 2230 1600 290 200 1100	3 1800 2740 2000 360 250 1300	5 2250 3240 2520 430 300 1700

The capacity of the electric arc furnace can be determined according to the output of the design product, the variety and the raw material condition used, and the capacity of the transformer. Generally, it can be calculated by the following formula:

W=P/(K·N·T) [1]

Where W is the nominal capacity of the transformer, kVA;

P——the output of rare earth ferrosilicon alloy, t;

K——the raw material coefficient, generally taking 1.0 to 1.3, the lower limit of the rare earth rich slag, and the upper limit of the rare earth concentrate slag;

N——Electric arc furnace utilization factor, t/(MVA·d);

T - annual working time, d.

(1) Top hopper charge Because the solid rare earth rich slag has poor conductivity, it can only be used after the first arc is charged. The charge is first loaded into the hopper for calculation, and then transported by crane to the top of the furnace for storage. After the arc furnace starts to arc, the gate of the silo can be opened when the feeding is needed, and the charging material flows from the feeding hole of the furnace cover to the furnace through the guiding tube. Each electric arc furnace can be provided with 1 or 2 feeding holes according to the size of its capacity.

(2) Increasing the depth of the molten pool Because the volume of the smelting rare earth ferrosilicon is large, and the slag boiling often occurs during smelting, it is necessary to increase the depth of the molten pool and enlarge the volume of the molten pool to meet the requirements of smelting rare earth silicon alloy. . In practice, it is often used to increase the position of the furnace door to increase the depth of the molten pool.

(3) Adopting carbonaceous lining Because the fluorine-containing rare earth slag has strong corrosiveness to the lining of the alkaline refractory material, the life of the lining is short, and the operating rate of the electric arc furnace is reduced. Carbon lining.

(4) Adding smoke and dust removal facilities A large amount of flue gas is generated in the process of smelting rare earth ferrosilicon alloy in electric arc furnace, and its dust content can reach 2g/m ³ , and contains harmful gases such as fluorine, which seriously deteriorates the working environment. At present, rare earth alloy production plants generally use hoods to collect flue gas, and use the induced draft fan to remove the flue gas through cloth bags or static electricity to achieve emission standards for flue gas emissions.

Figure (1) shows the equipment system for smelting rare earth ferrosilicon alloy by 5t arc.