阅读说明：本技术 一种封闭式生产大结晶电熔镁砂的装置 (Closed device for producing macrocrystalline fused magnesia ) 是由 邓乐锐 徐吉龙 赵金秋 章荣会 杨海峰 李娜 李玺 于 2021-02-02 设计创作，主要内容包括：本发明提供一种封闭式生产大结晶电熔镁砂的装置,包括轻烧氧化镁窑和矿热炉,所述轻烧氧化镁窑通过中间仓、链篦式给料机与矿热炉相连接,所述轻烧氧化镁窑匹配对接多套矿热炉,所述链篦式给料机通过菱镁矿粉溜管向矿热炉下料,所述链篦式给料机的外部设置有保温罩,所述中间仓和菱镁矿粉溜管的内壁均设置有隔热耐磨耐火材料。本发明使轻烧氧化镁粉封闭通道热送,减少热量损失,节约能源；通过大结晶电熔镁砂矿热炉烟气回收,可以利用烟气余热预热原材料；矿热炉通过烟气温度监测实现自动加料,对冶炼完毕的矿热炉炉筒进行保温,可单独加盖加罩也可集中放置到保温室内。(The invention provides a closed device for producing macrocrystalline fused magnesia, which comprises a light-burned magnesia kiln and a submerged arc furnace, wherein the light-burned magnesia kiln is connected with the submerged arc furnace through an intermediate bin and a chain grate type feeder, the light-burned magnesia kiln is matched and butted with a plurality of sets of submerged arc furnaces, the chain grate type feeder feeds materials to the submerged arc furnace through a magnesite powder chute, a heat preservation cover is arranged outside the chain grate type feeder, and heat-insulating wear-resistant refractory materials are arranged on the inner walls of the intermediate bin and the magnesite powder chute. The invention leads the light-burned magnesia powder to be delivered in a closed channel, reduces the heat loss and saves the energy; flue gas waste heat can be utilized to preheat raw materials by flue gas recovery of a large-crystallization fused magnesia ore heating furnace; the submerged arc furnace realizes automatic feeding through flue gas temperature monitoring, keeps warm to the submerged arc furnace section of thick bamboo that finishes smelting, can add to cover alone and add the cover also can concentrate and place in the heat preservation room.)

1. The utility model provides a device of large crystallization electric smelting magnesite grain of closed production which characterized in that: the light-burned magnesia kiln is connected with the submerged arc furnace through an intermediate bin and a chain grate feeder, the light-burned magnesia kiln is in butt joint with a plurality of sets of submerged arc furnaces in a matching mode, the chain grate feeder feeds materials to the submerged arc furnace through a magnesite powder chute, a heat preservation cover is arranged outside the chain grate feeder, and heat-insulating wear-resistant refractory materials are arranged on the inner walls of the intermediate bin and the magnesite powder chute.

2. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 1, wherein: the light-burned magnesia kiln adopts a rotary kiln, a rotary kiln hood is arranged at the front end of the rotary kiln, a light-burned magnesia powder chute is arranged on the rotary kiln hood, and the rear end of the rotary kiln is connected with the intermediate bin.

3. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 2, wherein: the middle bin is conical and is used for storing high-temperature light-burned magnesia powder which is just taken out of the kiln, and the lower end of the middle bin is connected with the chain grate type feeder.

4. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 1, wherein: the submerged arc furnace comprises a furnace body and a furnace cover, the lower end of the furnace body is fixed on the trolley, the furnace cover is arranged at the top of the furnace body, and a ceramic fiber sealing gasket is arranged between the lower portion of the furnace cover and the top of the furnace body.

5. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 1, wherein: the furnace cover of the submerged arc furnace is provided with a smoke hole and a blanking hole, the magnesite powder chute is connected with the blanking hole, and the smoke hole is located above the blanking hole.

6. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 5, wherein: the flue gas hole is connected with a flue gas recovery pipeline, the flue gas recovery pipeline comprises an obliquely upward extending pipeline and a vertical pipeline which are connected, and the tail end of the vertical pipeline is connected with the drying cylinder.

7. The closed type apparatus for producing macrocrystalline fused magnesia according to claim 5, wherein: the thermocouple is arranged at the vertical section of the flue gas recovery pipeline, sends a signal to the control system, and controls the starting of the feeding system through the control system.

Technical Field

The invention relates to a large-crystal fused magnesia production and processing device, in particular to a closed device for producing large-crystal fused magnesia.

Background

At present, most large-crystal fused magnesia is produced by adopting a two-step method. The two-step method is characterized in that firstly, the magnesite ore is lightly calcined at a lower temperature to obtain the lightly calcined magnesite powder with the MgO content of more than 90%. Then the light-burned magnesite powder is used as a raw material and put into a submerged arc furnace for large-crystal electric smelting of magnesium. The submerged arc furnace is mostly of an open structure. The smelted furnace barrel is generally placed in a workshop for natural cooling.

At present, the production process of light-burned magnesite dust and the production process of large-crystal electric fused magnesia are two independent links, the hot light-burned magnesite dust just coming out of a kiln can be gradually cooled to normal temperature for storage, and the heat energy is wasted.

After the light-burned magnesite powder at normal temperature enters the ore-smelting furnace, the light-burned magnesite powder is heated to a high temperature of more than 2800 ℃ to smelt large-crystal fused magnesite. But also needs more electric energy to heat the normal temperature raw materials.

The heat of the flue gas of the open submerged arc furnace cannot be utilized, the dust flies on the spot, and the operation environment is severe.

The furnace barrel after smelting is naturally cooled, the cooling speed is too high, the migration and enrichment of impurities in the melt are influenced, and the size, the output proportion and the purity of large-crystal magnesia grains are difficult to further improve.

Disclosure of Invention

The invention provides a closed device for producing large-crystal fused magnesia, which solves the problem of connection between a light-burned magnesia powder production process and a large-crystal fused magnesia production process, and adopts the following technical scheme:

the utility model provides a device of closed production macrocrystal electric smelting magnesia, includes light-burned magnesia kiln and hot stove in ore deposit, light-burned magnesia kiln is connected with the hot stove in ore deposit through intermediate bin, grate type batcher, light-burned magnesia kiln matches the many sets of hot stove in ore deposit of butt joint, grate type batcher passes through magnesite powder elephant trunk and to hot stove unloading in ore deposit, the outside of grate type batcher is provided with the heat preservation cover, the inner wall of intermediate bin and magnesite powder elephant trunk all is provided with thermal-insulated wear-resisting refractory material.

The light-burned magnesia kiln adopts a rotary kiln, a rotary kiln hood is arranged at the front end of the rotary kiln, a light-burned magnesia powder chute is arranged on the rotary kiln hood, and the rear end of the rotary kiln is connected with the intermediate bin.

The middle bin is conical and is used for storing high-temperature light-burned magnesia powder which is just taken out of the kiln, and the lower end of the middle bin is connected with the chain grate type feeder.

The submerged arc furnace comprises a furnace body and a furnace cover, the lower end of the furnace body is fixed on the trolley, the furnace cover is arranged at the top of the furnace body, and a ceramic fiber sealing gasket is arranged between the lower portion of the furnace cover and the top of the furnace body.

The furnace cover of the submerged arc furnace is provided with a smoke hole and a blanking hole, the magnesite powder chute is connected with the blanking hole, and the smoke hole is located above the blanking hole.

The flue gas hole is connected with a flue gas recovery pipeline, the flue gas recovery pipeline comprises an obliquely upward extending pipeline and a vertical pipeline which are connected, and the tail end of the vertical pipeline is connected with the drying cylinder.

The thermocouple is arranged at the vertical section of the flue gas collecting pipeline and sends a signal to the control system, and the control system controls the starting of the feeding system.

The closed device for producing the macrocrystalline fused magnesia has the following advantages:

(1) the light-burned magnesia powder is delivered in a closed channel, so that the heat loss is reduced, and the energy is saved;

(2) the chain grate belt is provided with a sealing cover, and heat insulation fibers are laid on the inner wall of the sealing cover, so that dust and heat loss in the feeding process are reduced;

(3) the chain grate machine can feed materials in two directions;

(4) the top of the submerged arc furnace is closed, so that the heat loss is reduced, smoke dust is prevented from flying out of the furnace, and the field operation environment is improved;

(5) the ceramic fiber gasket and the electrode sealing ring further reduce the loss of smoke in the furnace;

(6) flue gas in the submerged arc furnace is uniformly recovered through a closed pipeline and can be used for preheating raw materials, so that the temperature of the raw materials entering the furnace is increased, and the energy consumption is reduced;

(7) the automatic control of feeding into the submerged arc furnace is realized by monitoring the flue gas temperature of the submerged arc furnace;

(8) the furnace barrel after smelting is subjected to heat preservation treatment, so that the yield and the purity of the large-crystal magnesia are improved.

Drawings

FIG. 1 is a schematic structural view of the closed type apparatus for producing macrocrystalline fused magnesia;

the reference numbers in the figures: 1. a trolley; 2. a furnace body; 3. a sealing gasket; 4. a furnace cover; 5. magnesite powder chute; a chain grate feeder; 7. a rotary kiln hood; 8. lightly firing a magnesia powder chute; 9. a rotary kiln; 10. a middle bin; 11. an electrode; 12. an electrode seal ring; 13. flue gas collecting pipe.

Detailed Description

As shown in figure 1, the closed device for producing the large-crystal fused magnesia comprises a light-burned magnesia kiln and a submerged arc furnace, wherein the light-burned magnesia kiln is connected with a chain-grate feeder 6 through a middle bin 10, and is in butt joint with a plurality of sets of submerged arc furnaces through matching of the chain-grate feeder 6.

The light-burned magnesia kiln is a kiln for producing light-burned magnesia, and can be a shaft kiln, a rotary kiln, a fluidized bed furnace and the like, and the rotary kiln 9 is adopted in the invention. The front end of the rotary kiln 9 is provided with a rotary kiln hood 7, and the rotary kiln hood 7 is provided with a light-burned magnesia powder chute 8 for introducing light-burned magnesia powder. The rear end of the rotary kiln 9 is connected with a middle bin 10, and the light-burned magnesia powder which is just taken out of the kiln is conveyed to the middle bin 10 for storage.

The submerged arc furnace comprises a furnace body 2 and a furnace cover 4, the lower end of the furnace body 2 is fixed on the trolley 1, the furnace cover 4 is arranged at the top of the furnace body 2, and a ceramic fiber sealing gasket 3 is arranged between the lower portion of the furnace cover 4 and the top of the furnace body 2 to enhance the sealing effect. The inner wall of the furnace cover 4 is provided with a refractory material layer which plays roles of heat insulation and external steel shell protection, and the top of the furnace cover 4 is a refractory material prefabricated part with an electrode insertion hole. The gap between the electrode 11 and the electrode insertion hole is sealed by a combined sealing ring, the sealing ring is sleeved by two sealing rings, and the diameter of an inner hole formed by combination is equivalent to that of the electrode 11, so that the sealing ring can be tightly attached to the electrode 11.

The side wall of the furnace cover 4 is provided with a plurality of flue gas holes for connecting the inlets of the flue gas recovery pipelines. The side wall of the furnace cover 4 is also provided with a discharging hole, the discharging hole is connected with a discharging opening of the magnesite powder slide pipe 5 and used for discharging, and a feeding opening of the magnesite powder slide pipe 5 is connected with the chain grate type feeder 6. Wherein, the height of the flue gas hole is slightly higher than that of the discharging hole, so that the fine powder is prevented from being brought out by the flue gas.

The flue gas recovery pipeline connected with the furnace cover 4 extends upwards in an inclined way at first and then forms a section of vertical pipeline, and the vertical pipeline is beneficial to fine powder brought out by the flue gas to slide back into the furnace. The flue gas is finally introduced into the head of the drying cylinder through a closed pipeline. The inner wall of the flue gas recovery pipeline is provided with a heat insulation refractory material or a ceramic heat insulation material, so that heat loss of flue gas in the pipeline is reduced, and the rear end can preheat raw materials by utilizing flue gas waste heat.

The vertical section part of the flue gas collecting pipeline of each submerged arc furnace is provided with a thermocouple for monitoring the temperature of the flue gas of the furnace. And realizing automatic control of charging into the submerged arc furnace according to the temperature signal. The thermocouple sends a signal to a control system, and the control system controls the starting of a feeding system, wherein the feeding system comprises a chain-grate feeder 6. Along with the powder melting progress in the ore heating furnace, the flue gas temperature can rise gradually, and when the ore heating furnace flue gas temperature reaches and sets up the upper limit temperature, 6 automatic start-up of grate feeder are through adding the raw materials in magnesite powder elephant trunk 5 to corresponding ore heating furnace. The flue gas temperature can reduce gradually in the feeding process, and when the flue gas temperature reaches the set lower limit temperature, the feeding operation is automatically stopped.

The invention carries out hot delivery on the high-temperature light-burned magnesia powder which is just taken out of the kiln through the chain grate type feeder 6 with the heat preservation cover, and the ceramic fiber felt is laid on the inner wall of the heat preservation cover to play the role of heat insulation and preservation. The intermediate bin 10 is used as a hot material storage bin, and heat-insulating wear-resistant refractory materials are arranged on the inner walls of the intermediate bin and the magnesite powder chute 5, so that heat loss is reduced.

The invention realizes the connection of the light-burned magnesia production kiln and the large-crystallization electric melting ore furnace, realizes the hot delivery of the light-burned magnesia powder into the ore furnace, realizes the hot delivery of the light-burned magnesia powder by adopting a grate feeder, the grate is made of heat-resistant steel, the outer part of the grate feeder is provided with a heat-insulating cover, and the inner wall of the heat-insulating cover is paved with heat-insulating fibers. Wherein, the chain grate machine can feed materials bidirectionally. The invention can utilize the flue gas waste heat to preheat the raw materials by recycling the flue gas of the large-crystal fused magnesia ore heating furnace. The submerged arc furnace realizes automatic feeding through flue gas temperature monitoring, keeps warm to the submerged arc furnace section of thick bamboo that finishes smelting, can add to cover alone and add the cover also can concentrate and place in the heat preservation room. It has the following characteristics:

1. the technical proposal connects a kiln for producing light-burned magnesite powder and an ore-smelting furnace for producing large-crystal fused magnesite. The light-burned magnesia powder which is just taken out of the kiln is thermally conveyed by a chain grate type feeder 6 with a heat preservation cover and enters a transfer bin in a high-temperature state or directly enters the submerged arc furnace. One set of light-burned magnesia powder kiln can simultaneously provide high-temperature light-burned magnesia powder raw materials for a plurality of sets of submerged arc furnaces.

2. The submerged arc furnace is covered and sealed, and the high-temperature flue gas in the submerged arc furnace is recycled in a centralized manner.

3. A temperature sensor is arranged at a proper position of the vertical section of the flue gas recovery pipeline and is used for continuously monitoring the temperature change condition of flue gas in the furnace in real time on line. The upper layer of the furnace body has a dry powder layer with a certain thickness in the smelting process, and the function of arc shielding and heat insulation is achieved. In the smelting process, the dry powder layer can be continuously melted and thinned, even completely melted, and at the moment, the materials need to be fed in time to ensure the proper thickness of the dry powder layer. The process that the dry powder layer becomes thin and even disappears will lead to the rise of the smoke temperature, and the automatic control of the blanking is realized by monitoring the smoke temperature signal. The blanking action is triggered when the smoke temperature reaches the set upper limit, the feeding system starts blanking at a constant speed, the smoke temperature is reduced along with the gradual thickening of a dry powder layer in the furnace in the blanking process, and the blanking is stopped when the smoke temperature reaches the set lower limit, so that the unsmooth exhaust in the furnace caused by the over-thick dry powder layer is avoided.