CN115468419A - Device and method for removing boron impurities in metallurgical-grade silicon in ore-smelting furnace - Google Patents

Abstract

The invention discloses a device for removing boron impurities in metallurgical-grade silicon in an ore-smelting furnace, which comprises the ore-smelting furnace, wherein a heating electrode is fixedly connected and arranged at the bottom in the ore-smelting furnace, a heat transfer plate is fixedly connected and arranged in the ore-smelting furnace, the heat transfer plate is positioned on the upper side of the heating electrode and is correspondingly matched with the heating electrode, a feed inlet is arranged on the upper left side in the ore-smelting furnace, a feed pipe is fixedly connected and arranged on the lower side of the feed inlet, a piston block is sleeved in the feed inlet in a matching manner, the piston block penetrates through the feed inlet, a rotating rod is rotatably connected and arranged on the upper side in the ore-smelting furnace, the rotating rod is positioned on the right side of the feed inlet, and a plurality of stirring rods are symmetrically and fixedly connected and arranged on the side wall of the rotating rod. The invention is smelted in the ore-smelting furnace, a graphite crucible is not needed, the production cost is reduced, the silicon liquid is prevented from being polluted by carbon elements, the boron impurities obtain good mass transfer conditions between the slag liquid and the silicon liquid, and the slag silicon is separated more thoroughly.

Description

A device and method for removing boron impurities in metallurgical grade silicon in a submerged arc furnace

technical field

The invention relates to the technical field of metallurgical-grade silicon purification, in particular to a device and method for removing boron impurities in metallurgical-grade silicon in a submerged arc furnace.

Background technique

Due to the many disadvantages of non-renewable and environmental pollution in the use of traditional energy, crystalline silicon solar cells have gradually attracted global attention due to their green advantages. China adds about 18 million kilowatts of photovoltaic power generation equipment every year. In order to meet the rapid development of photovoltaic equipment Therefore, researchers have made a lot of efforts in the field of low-cost and short-process production of solar-grade silicon. The boron content has a great impact on the photoelectric conversion efficiency and stability of solar cells. Generally, the B content in qualified solar silicon wafers is less than 0.3×10 ^-6 , P content below 0.5×10 ^-6 , Fe, Al, Ca and other metal impurities at 0.1×10 ^-6 ; Fe, Al, Ca and other metal impurities can be removed by directional solidification because of their small segregation coefficient; P , Ca and other impurities with high saturated vapor pressure can be removed by vacuum smelting, but B impurities cannot be removed by the above two methods. hot research areas.

Chinese patent CN02135841.9 (Zheng Zhixiong, a kind of high-purity silicon for solar cells and its production method) discloses a method for preparing solar-grade polysilicon by adding fluorite, iron oxide, lime, etc. to silicon melt, and its essence is The B impurities in silicon are oxidized into BO, B ₂ O ₃ , B ₂ O, BO ₂ , B ₂ O ₂ and other boron oxides through the method of CaF ₂ -CaO slagging oxidation refining, and boron oxides are used in the slag system The property that the SS free energy is lower than the Gibbs free energy in the silicon liquid makes the boron oxide tend to enter the slag liquid, and realizes the removal of B impurities in the silicon liquid. The metallurgical and mineral processing laboratory of Xiamen University successfully reduced the B content to 0.15-0.7ppmw at 1650-1750°C through the slag-making experiment of CaO-SiO ₂ -CaF ₂ -BaO slag system (Cai Jing, Chen Chao, Luo Xuetao, Research progress on boron removal from high-purity metallurgical silicon, Materials Bulletin, 2009, 23(12):81-84).

U.S. Patent US200501391485 (Fujiwara Hiroyasu et al., Silicon purifying method, slag for purifying silicon, and purified silicon) reduces the content of silicon B from 7.4 ppm to 0.8 ppm by using CaO-SiO ₂ slag system, but this method requires gas blowing and manufacturing slag at the same time.

Patent CN101671023A discloses a method for polysilicon slagging and boron removal. Two kinds of slagging agents are used, the first is Na ₂ O+SiO ₂ ; the second is CaO+CaF ₂ +SiO ₂ , which can reduce the B content in polysilicon to Reduced to 0.18ppm, but the process requires vacuum conditions.

The above process has the following disadvantages in the production process: 1. The graphite crucible used in the smelting process has a short service life, which leads to high cost of slagging and boron removal; 2. The addition of CaF ₂ seriously corrodes the crucible and equipment; The production equipment has higher requirements, which makes the technology unfavorable for popularization.

Contents of the invention

The purpose of the present invention is to solve the shortcomings in the prior art, such as: the cost of overall boron removal is high, the equipment is corroded seriously, the process requirements are high, which is not conducive to popularization and production, and a proposed method in submerged arc furnace A device and method for removing boron impurities from metallurgical grade silicon.

In order to achieve the above object, the present invention adopts the following technical solutions:

A device for removing boron impurities in metallurgical grade silicon in a submerged arc furnace, comprising a submerged arc furnace, the bottom of the submerged arc furnace is fixedly connected with a heating electrode, and the inside of the submerged arc furnace is fixedly connected with a temperature transfer plate, so The temperature transfer plate is located on the upper side of the heating electrode and matched with the heating electrode. The upper left side of the submerged arc furnace is provided with a feeding port, and the lower side of the feeding port is fixedly connected with a feeding pipe. The matching sleeve in the feed port is provided with a piston block, the piston block is set through the feed port, and the upper side of the submerged arc furnace is rotatably connected with a rotating rod, and the rotating rod is located on the right side of the feed port. The side wall of the rotating rod is symmetrically fixedly connected with a plurality of stirring rods, and the outer side of the rotating rod is also fixedly provided with a first gear, and the first gear is located on the upper side of the plurality of stirring rods. There is a control rod, and the control rod is set through the submerged arc furnace, and the control rod is fixedly connected to a second gear in the submerged arc furnace, and the second gear and the first gear are meshed and connected, and the submerged arc furnace There is a fixed connection and a hose inside, and the hose is installed through the submerged arc furnace. One end of the hose is located in the submerged arc furnace and is fixedly connected with a control ring. control device.

Preferably, the mobile control device includes a fixed plate fixedly connected in the submerged arc furnace, the fixed plate is located on the lower side of the second gear, the upper side of the fixed plate is provided with an inner gear ring, the fixed An annular groove is arranged on the upper side of the plate, and two sliding rods are arranged for symmetrical sliding connection in the annular groove, and the two sliding rods penetrate through the annular groove and are fixedly connected to the inner gear ring, and the inner gear ring and the second gear Matching corresponding settings, the internal meshing sleeve of the inner gear ring is provided with a third gear that is the same as the second gear, the lower side of the third gear is fixedly connected with a first spring, and the other side of the first spring is connected to the second gear. The fixed plate is fixedly connected, and the outer side of the inner gear ring is provided with a wire groove, and a control line is wound and connected in the wire groove, and the control wire is set through the wire groove, and the upper side of the control ring is fixedly connected with a The pull ring is fixedly connected with the control wire and the pull ring.

Preferably, the right side of the submerged arc furnace is fixedly connected with a first fixed ring, the upper side of the submerged arc furnace is fixedly connected with a second fixed ring, and the control line runs through the first fixed ring and the second fixed ring. Retaining ring set.

Preferably, a square hole is provided on the upper side of the fixing plate, a square rod is slidingly sleeved in the square hole, the square rod passes through the square hole, and the square rod is fixedly connected to the third gear.

Preferably, the inner side wall of the submerged arc furnace is provided with a chute, and a slider is slidably connected in the chute, and the slider is fixedly connected through the chute and the control ring.

Preferably, the control rod is located in the submerged arc furnace and is provided with a control cylinder, the control cylinder is located on the upper side of the second gear, the control rod is located in the control cylinder and is fixedly sleeved with a moving ring, and the moving ring The lower side of the second spring is fixedly connected with a second spring, and the other side of the second spring is fixedly connected with a rotating ring, and the rotating ring and the bottom of the control cylinder are rotationally connected, and the inner fixed sleeve of the control cylinder is provided with a limit ring, the limit ring is located on the upper side of the moving ring and is set in contact with the moving ring.

A method for removing boron impurities in metallurgical grade silicon in a submerged arc furnace, comprising the following steps:

S1. First, take out the piston block from the feed port, put the metallurgical silicon into the submerged arc furnace, start the heating electrode, and start smelting until all the raw silicon becomes liquid silicon;

S2. Put the mixed Na ₂ CO ₃ -SiO ₂ slag agent into the silicon liquid through the feed port and the feed pipe and keep it warm;

S3, put the mixed CaO _- SiO slag agent into the silicon liquid through the feed port and the feed pipe and keep it warm;

S4. After the overall reaction is completed, move the control lever downward, the control lever drives the moving ring to move downward, the moving ring compresses the second spring, and the control lever also drives the second gear to move downward, the second gear and the third gear Contact and drive the third gear to move downward, the third gear compresses the first spring until the third gear and the inner gear ring are disconnected, and the inner gear ring and the second gear are engaged and connected, turn the control lever, and the control lever passes through The second gear drives the inner gear ring to rotate, and under the action of the control line and the control ring’s own gravity, the control ring moves downward until the control ring moves to the upper side of the slag boundary layer. Extract the slag liquid, repeat the above operation, and then take out the silicon liquid.

Preferably, during the process of adding raw silicon, Na ₂ CO ₃ -SiO ₂ slag agent and CaO-SiO ₂ slag agent, the control rod is rotated, and the control rod drives the rotation rod to rotate through the second gear and the first gear, and the rotation rod Drive the stirring rod to rotate, carry out the corresponding stirring operation, and reduce the mixing time.

Preferably, the weight ratio of Na ₂ CO ₃ -SiO ₂ slag agent to metallurgical silicon in the step S2 is 45:100; the mass percentage of Na ₂ CO ₃ in the Na ₂ CO ₃ -SiO ₂ slag agent It is 64%-69.5%, and the balance is SiO ₂ ; the holding temperature is 1800-1950° C.; the holding time is 20-30 minutes.

Preferably, the weight ratio of the CaO-SiO ₂ slag agent to metallurgical silicon in the step S3 is 87:100; the mass percentage of the CaO-SiO ₂ slag agent CaO is 70%-74%, and the balance is SiO ₂ ; the holding temperature is 1800-1900° C.; the holding time is 30-40 minutes.

Compared with prior art, the beneficial effect of the present invention is:

1. Due to the smelting in the submerged arc furnace, no graphite crucible is needed, which reduces the production cost and avoids the pollution of silicon liquid by carbon elements;

2. The slag agent formulated does not contain CaF ₂ , which alleviates the corrosion of equipment during the smelting process;

3. The Na ₂ O-SiO ₂ slag liquid is located above the silicon liquid, and after the CaO-Na ₂ O-SiO ₂ slag liquid is formed, the slag liquid sinks and the silicon liquid floats up, and the B impurities obtain good mass transfer between the slag liquid and the silicon liquid Conditions; 4. After the slag-silicon liquid is stratified, the slag liquid can be discharged first, and the separation effect is good.

Description of drawings

Fig. 1 is a kind of structural representation of the device and method for removing boron impurities in metallurgical grade silicon in submerged arc furnace that the present invention proposes;

Fig. 2 is a kind of top view connection schematic diagram between control ring and submerged arc furnace in the device and method for removing boron impurities in metallurgical grade silicon in submerged arc furnace proposed by the present invention;

Fig. 3 is a kind of device and method for removing boron impurities in metallurgical grade silicon proposed by the present invention and the connection schematic diagram of control ring, flexible pipe and draw ring;

Fig. 4 is the enlarged structure diagram of place A in Fig. 1;

Fig. 5 is a kind of structure enlarged view of the control cylinder in the device and method for removing boron impurities in metallurgical grade silicon in submerged arc furnace proposed by the present invention;

Fig. 6 is a schematic diagram of a device and method for removing boron impurities in metallurgical grade silicon in a submerged arc furnace proposed by the present invention.

In the figure: 1 submerged arc furnace, 2 temperature transfer plate, 3 heating electrode, 4 rotating rod, 5 stirring rod, 6 first gear, 7 feeding port, 8 feeding pipe, 9 piston block, 10 control rod, 11 first gear Second gear, 12 third gear, 13 first spring, 14 fixed plate, 15 square hole, 16 square rod, 17 second fixed ring, 18 control cylinder, 19 control ring, 20 pull ring, 21 chute, 22 slider , 23 flexible pipes, 24 internal gear rings, 25 wire grooves, 26 control lines, 27 first fixed rings, 28 annular grooves, 29 slide bars, 30 moving rings, 31 second springs, 32 limit rings, 33 rotating rings.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention.

In describing the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", " The orientation or positional relationship indicated by "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, so as to Specific orientation configurations and operations, therefore, are not to be construed as limitations on the invention.

Referring to Figures 1-6, a device for removing boron impurities in metallurgical grade silicon in a submerged arc furnace 1 includes a submerged arc furnace 1, and a heating electrode 3 is fixedly connected to the inner bottom of the submerged arc furnace 1. The fixed connection is provided with a temperature transfer plate 2, and the temperature transfer plate 2 is located on the upper side of the heating electrode 3 to match the heating electrode 3. The heating electrode 3 is a prior art, so no redundant description is made. The upper left of the submerged arc furnace 1 The side is provided with a feed port 7, the lower side of the feed port 7 is fixedly connected with a feed pipe 8, and the matching sleeve of the feed port 7 is provided with a piston block 9, and the piston block 9 is set through the feed port 7. 1. A rotating rod 4 is arranged on the upper side of the rotating connection. The rotating rod 4 is located on the right side of the feed port 7. The side wall of the rotating rod 4 is symmetrically fixedly connected with a plurality of stirring rods 5. The outer side of the rotating rod 4 is also fixedly sleeved. The first gear 6, the first gear 6 is located on the upper side of a plurality of stirring rods 5, the submerged arc furnace 1 is provided with a control rod 10, the control rod 10 runs through the submerged arc furnace 1, and the control rod 10 is located in the submerged arc furnace 1 The inner fixed connection is provided with a second gear 11, and the second gear 11 and the first gear 6 are meshed and connected. The submerged arc furnace 1 is provided with a fixed connection and a hose 23 is provided. The hose 23 runs through the submerged arc furnace 1 and is set. The pipe 23 is located in the submerged arc furnace 1 and one end is fixedly connected with a control ring 19. The submerged arc furnace 1 is provided with a mobile control device for the control ring 19. The mobile control device includes a fixed plate 14 fixedly connected in the submerged arc furnace 1. The fixed plate 14 is arranged on the lower side of the second gear 11, the upper side of the fixed plate 14 is provided with an inner gear ring 24, the upper side of the fixed plate 14 is provided with an annular groove 28, and two sliding rods are arranged for symmetrical sliding connection in the annular groove 28 29, two sliding rods 29 penetrate through the annular groove 28 and are fixedly connected with the inner gear ring 24, and the inner gear ring 24 and the second gear 11 are matched and correspondingly arranged, and the inner gear ring 24 is provided with the same The third gear 12, the lower side of the third gear 12 is fixedly connected with the first spring 13, the other side of the first spring 13 is fixedly connected with the fixed plate 14, and the outer side of the inner gear ring 24 is provided with a wire groove 25, the wire groove 25 is wound and connected with a control line 26, the control line 26 is set through the wire groove 25, and the upper side of the control ring 19 is fixedly connected with a pull ring 20, and the control line 26 and the pull ring 20 are fixedly connected and set. The right side is fixedly connected with a first fixed ring 27, and the upper side of the submerged arc furnace 1 is fixedly connected with a second fixed ring 17. The control line 26 runs through the first fixed ring 27 and the second fixed ring 17. Cooperate between the fixed ring 27 and the second fixed ring 17 to complete the simple restriction operation on the trajectory of the control line 26. The upper side of the fixed plate 14 is provided with a square hole 15, and the sliding sleeve in the square hole 15 is provided with a square rod 16. The square rod 16 runs through the square hole 15, and the square rod 16 and the third gear 12 are fixedly connected to determine and limit the movement track of the third gear 12, so that a better connection between the third gear 12 and the inner gear ring 24 can be achieved. To carry out the meshing connection operation, the inner side wall of the submerged arc furnace 1 is provided with a chute 21, and the sliding connection in the chute 21 is provided with a slider 22, and the slider 22 runs through the chute 21 It is fixedly connected with the control ring 19 to complete the simple limit operation of the control ring 19. The control rod 10 is located in the submerged arc furnace 1 and is provided with a control cylinder 18. The control cylinder 18 is located on the upper side of the second gear 11. The control rod 10 A moving ring 30 is fixedly set inside the control cylinder 18, a second spring 31 is fixedly connected to the lower side of the moving ring 30, and a rotating ring 33 is fixedly connected to the other side of the second spring 31, and the rotating ring 33 and the control cylinder are fixedly connected. The bottom of 18 is rotated and connected, and the control cylinder 18 is fixedly sleeved with a limit ring 32. The limit ring 32 is located on the upper side of the moving ring 30 and is connected to the moving ring 30. The second spring 31 and the limit ring in the control cylinder 18 The positioning ring 32 completes the limiting and fixing operation of the moving ring 30 , and further completes the limiting and fixing operation of the control rod 10 .

A method for removing boron impurities in metallurgical grade silicon in a submerged arc furnace 1, comprising the following steps:

S1. First, take out the piston block 9 from the feed port 7, put the metallurgical silicon into the submerged arc furnace 1, start the heating electrode 3, and start smelting until all the raw silicon becomes silicon liquid;

S2. Put the mixed Na ₂ CO ₃ -SiO ₂ slag agent into the silicon liquid through the feed port 7 and the feed pipe 8 and keep it warm. The weight ratio of Na ₂ CO ₃ -SiO ₂ slag agent to metallurgical silicon is 45:100; the mass percentage of Na ₂ CO ₃ in the Na ₂ CO ₃ -SiO ₂ slag agent is 64%-69.5%, and the balance is SiO ₂ ; the holding temperature is 1800-1950°C; the The holding time is 20-30 minutes;

S3, put the mixed CaO- _SiO2 slag agent into the silicon liquid through the feed port 7 and the feed pipe 8 and keep it warm, the weight ratio of CaO- _SiO2 slag agent to metallurgical silicon is 87:100; The mass percentage of CaO-SiO ₂ slag agent CaO is 70%-74%, and the balance is SiO ₂ ; the holding temperature is 1800-1900°C; the holding time is 30-40 minutes;

S4. After the overall reaction is completed, move the control lever 10 downward, the control lever 10 drives the moving ring 30 to move downward, the moving ring 30 compresses the second spring 31, and the control lever 10 also drives the second gear 11 to move downward, The second gear 11 is in contact with the third gear 12 and drives the third gear 12 to move downward, and the third gear 12 compresses the first spring 13 until the connection between the third gear 12 and the inner gear ring 24 is disconnected, and the inner gear ring 24 Rotate the control lever 10 until it meshes with the second gear 11, the control lever 10 drives the inner gear ring 24 to rotate through the second gear 11, and the control ring 19 moves downward under the action of the control line 26 and the control ring 19's own gravity , until the control ring 19 moves to the upper side of the slag boundary layer, use the hose 23 and the corresponding press to extract the slag liquid, repeat the above operation, and then take out the silicon liquid, and carry out the raw material silicon, Na ₂ CO ₃ -SiO ₂ During the addition of slag agent and CaO-SiO ₂ slag agent, turn the control rod 10, the control rod 10 drives the rotation rod 4 to rotate through the second gear 11 and the first gear 6, and the rotation rod 4 drives the stirring rod 5 to rotate, and the corresponding The stirring operation reduces the mixing time.

In the present invention, first, the piston block 9 is taken out from the feed port 7, the metallurgical silicon is put into the submerged arc furnace 1, the heating electrode 3 is started, and the smelting starts. Until all the raw silicon becomes silicon liquid; put the mixed Na ₂ CO ₃ -SiO ₂ slag agent into the silicon liquid through the feed port 7 and the feed pipe 8 and keep it warm, wherein the Na ₂ CO ₃ -SiO ₂ slag agent and The weight ratio of metallurgical silicon is 45:100; the mass percentage of Na ₂ CO ₃ in the Na ₂ CO ₃ -SiO ₂ slag agent is 64%-69.5%, and the balance is SiO ₂ ; the holding temperature is 1800-1950°C ; The holding time is 20-30 minutes; the CaO-SiO ₂ slag agent that will be mixed is dropped in the silicon liquid through feed inlet 7 and feed pipe 8 and kept warm, wherein CaO-SiO _The weight ratio of slag agent and metallurgical silicon is 87:100; the mass percentage of CaO-SiO ₂ slag agent CaO is 70%-74%, and the balance is SiO ₂ ; the holding temperature is 1800-1900°C; the holding time is 30-40 minutes; after the overall reaction is completed , move the control rod 10 downward, the control rod 10 drives the moving ring 30 to move downward, the moving ring 30 compresses the second spring 31, and the control rod 10 also drives the second gear 11 to move downward, the second gear 11 and the third The gears 12 contact and drive the third gear 12 to move downward, the third gear 12 compresses the first spring 13 until the connection between the third gear 12 and the inner gear ring 24 is disconnected, and the inner gear ring 24 and the second gear 11 are meshed and connected until the control rod 10 is rotated, the control rod 10 drives the inner gear ring 24 to rotate through the second gear 11, and under the action of the control line 26 and the control ring 19's own gravity, the control ring 19 moves downward until the control ring 19 moves to As far as the upper side of the slag boundary layer, use the hose 23 and the corresponding press to extract the slag liquid, repeat the above operation, and then take out the silicon liquid, and carry out the raw material silicon, Na ₂ CO ₃ -SiO ₂ slag agent and CaO-SiO ₂ During the addition of slag agent, turn the control rod 10, the control rod 10 drives the rotating rod 4 to rotate through the second gear 11 and the first gear 6, and the rotating rod 4 drives the stirring rod 5 to rotate, and performs corresponding stirring operations to reduce mixing In time, the B impurity in the silicon liquid diffuses to the slag-silicon interface and is oxidized by Na ₂ O, the decomposition product of Na ₂ CO ₃ , CaO, an alkaline earth metal oxide, and SiO ₂ that can provide free [O]. Since boron oxides BO, B ₂ O ₃ , B ₂ O, BO ₂ , B ₂ O ₂ have lower Gibbs free energy in the slag system, boron oxides tend to enter the slag liquid, realizing Removal of B impurities in silicon liquid. In addition, since the density of the formed Na ₂ O-SiO ₂ slag liquid is lower than that of the silicon liquid, the slag liquid is located above the silicon liquid; when the mixed CaO-SiO ₂ slag agent is added, the CaO-Na ₂ O-SiO ₂ slag system is formed, At this time, the density of the slag liquid is greater than that of the silicon liquid; convection is formed between the scum liquid and the scum liquid on the sinking silicon liquid, which increases the contact area between the slag liquid and the silicon liquid, and improves the mass transfer of impurities between the slag liquid and the silicon liquid. Dynamic conditions improve the overall boron removal effect. After the reaction reaches equilibrium, stratification occurs between the slag-silicon liquid. separation.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (10)

1. The utility model provides a get rid of device of boron impurity in metallurgical grade silicon in ore smelting furnace, includes hot stove in ore smelting (1), its characterized in that, bottom fixed connection is equipped with heating electrode (3) in hot stove in ore smelting (1), fixed connection is equipped with heat transfer board (2) in hot stove in ore smelting (1), upside and the matching of heating electrode (3) that heat transfer board (2) are located heating electrode (3) correspond the setting, upward the left side is equipped with feed inlet (7) in hot stove in ore smelting (1), feed inlet (7) downside fixed connection is equipped with inlet pipe (8), the matching cover is equipped with piston block (9) in feed inlet (7), piston block (9) run through in feed inlet (7) setting, upside rotation connection is equipped with dwang (4) in hot stove in ore smelting (1), dwang (4) are located the right side setting of feed inlet (7), lateral wall symmetry fixed connection of dwang (4) is equipped with a plurality of dwang puddlers (5), fixed cover still is equipped with first gear (6) in the outside of ore smelting (4), first gear (6) are located the upside setting of a plurality of puddlers (5), be equipped with ore smelting (10) control rod (10) in ore smelting (10) control rod (10), second gear (11) and first gear (6) meshing connection set up, it is equipped with fixed connection and is equipped with hose (23) to be equipped with in hot stove in the ore deposit (1), hose (23) run through in hot stove in the ore deposit (1) setting, hose (23) are located hot stove in the ore deposit (1) one end fixed connection and are equipped with control ring (19), be equipped with the mobile control device of control ring (19) in the hot stove in the ore deposit (1).

2. An apparatus according to claim 1 for removing boron impurities from metallurgical grade silicon in a submerged arc furnace, it is characterized in that the mobile control device comprises a fixed plate (14) fixedly connected and arranged in the submerged arc furnace (1), the fixing plate (14) is arranged at the lower side of the second gear (11), an inner gear ring (24) is arranged on the upper side of the fixing plate (14), an annular groove (28) is arranged on the upper side of the fixing plate (14), two sliding rods (29) are symmetrically and slidably connected in the annular groove (28), the two sliding rods (29) penetrate through the annular groove (28) and the inner gear ring (24) to be fixedly connected, the inner gear ring (24) and the second gear (11) are correspondingly matched, a third gear (12) which is the same as the second gear (11) is sleeved in the inner gear ring (24), a first spring (13) is fixedly connected with the lower side of the third gear (12), the other side of the first spring (13) is fixedly connected with the fixing plate (14), a wire guide groove (25) is arranged on the outer side of the inner gear ring (24), a control wire (26) is wound and connected in the wire guide groove (25), the control wire (26) is arranged by penetrating through the wire guide groove (25), the upper side of the control ring (19) is fixedly connected with a pull ring (20), the control line (26) and the pull ring (20) are fixedly connected.

3. The device for removing the boron impurities in the metallurgical grade silicon in the submerged arc furnace according to the claim 2, characterized in that a first fixing ring (27) is fixedly connected to the right side in the submerged arc furnace (1), a second fixing ring (17) is fixedly connected to the upper side in the submerged arc furnace (1), and the control wire (26) is arranged to penetrate through the first fixing ring (27) and the second fixing ring (17).

4. The device for removing boron impurities in metallurgical-grade silicon in the ore smelting furnace according to claim 2, characterized in that the fixing plate (14) is provided with a square hole (15) at the upper side, a square rod (16) is slidably sleeved in the square hole (15), the square rod (16) penetrates through the square hole (15), and the square rod (16) and the third gear (12) are fixedly connected.

5. The device for removing the boron impurities in the metallurgical-grade silicon in the submerged arc furnace according to the claim 1, characterized in that the inner side wall of the submerged arc furnace (1) is provided with a sliding chute (21), the sliding chute (21) is internally and slidably connected with a sliding block (22), and the sliding block (22) is fixedly connected with a control ring (19) through the sliding chute (21).

6. The device for removing boron impurities in metallurgical-grade silicon in the submerged arc furnace according to claim 1, wherein the control rod (10) is positioned in the submerged arc furnace (1) and sleeved with a control cylinder (18), the control cylinder (18) is positioned on the upper side of the second gear (11), the control rod (10) is positioned in the control cylinder (18) and sleeved with a moving ring (30), the lower side of the moving ring (30) is fixedly connected with a second spring (31), the other side of the second spring (31) is fixedly connected with a rotating ring (33), the rotating ring (33) is rotatably connected with the bottom of the control cylinder (18), the control cylinder (18) is sleeved with a limiting ring (32), and the limiting ring (32) is positioned on the upper side of the moving ring (30) and in contact connection with the moving ring (30).

7. A method for removing boron impurities in metallurgical-grade silicon in a submerged arc furnace is characterized by comprising the following steps:

s1, firstly, taking out a piston block (9) from a feeding hole (7), putting metallurgical silicon into a submerged arc furnace (1), starting a heating electrode (3) and smelting until all raw material silicon is changed into silicon liquid;

s2, mixing the Na ₂ CO ₃ -SiO ₂ Slag agents are put into the silicon liquid through a feeding hole (7) and a feeding pipe (8) and are kept warm;

s3, mixing the evenly mixed CaO-SiO ₂ Slag agents are put into the silicon liquid through a feeding hole (7) and a feeding pipe (8) and are kept warm;

s4, after the integral reaction is finished, the control rod (10) is moved downwards, the control rod (10) drives the moving ring (30) to move downwards, the moving ring (30) compresses the second spring (31), the control rod (10) can also drive the second gear (11) to move downwards, the second gear (11) is in contact with the third gear (12) and drives the third gear (12) to move downwards, the third gear (12) compresses the first spring (13) until the third gear (12) is disconnected with the inner gear ring (24), the inner gear ring (24) is meshed with the second gear (11) and connected, the control rod (10) is rotated, the control rod (10) drives the inner gear ring (24) to rotate through the second gear (11), the control ring (19) is moved downwards under the self-gravity action of the control wire (26) and the control ring (19), until the control ring (19) moves to the upper side of a slag boundary layer, the slag liquid is extracted through the hose (23) and then is repeatedly extracted.

8. A method according to claim 7, characterized in that the raw material silicon, na is processed ₂ CO ₃ -SiO ₂ Slag agent and CaO-SiO ₂ In the adding process of the slag agent, the control rod (10) is rotated, the control rod (10) drives the rotating rod (4) to rotate through the second gear (11) and the first gear (6), the rotating rod (4) drives the stirring rod (5) to rotate, corresponding stirring operation is carried out, and the mixing time is shortened.

9. The method for removing boron impurities in metallurgical grade silicon in ore furnace according to claim 7, wherein Na in step S2 ₂ CO ₃ -SiO ₂ The weight ratio of the slag agent to the metallurgical silicon is 45; said Na ₂ CO ₃ -SiO ₂ Na in slag agent ₂ CO ₃ The mass percentage of the silicon dioxide is 64 percent to 69.5 percent, and the balance is SiO ₂ (ii) a The heat preservation temperature is 1800-1950 ℃; the heat preservation time is 20-30 minutes.

10. The method for removing boron in a submerged arc furnace according to claim 7, wherein CaO-SiO in the step S3 ₂ The weight ratio of the slag agent to the metallurgical silicon is 87; the CaO-SiO ₂ The weight percentage content of the slag agent CaO is 70 percent to 74 percent, and the rest is SiO ₂ (ii) a The heat preservation temperature is 1800-1900 ℃; the heat preservation time is 30-40 minutes.

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