Device for preparing high-purity silicon dioxide from silicon-containing tailings

Abstract

A device for preparing high-purity silicon dioxide from silicon-containing tailings, comprising an alkali reaction kettle and a sedimentation tank, a movable hose is connected to the liquid outlet of the sedimentation tank, an acid precipitation kettle is connected to the pipeline of the liquid outlet, a filter is connected to the acid precipitation kettle, a vertical ball mill is arranged at the rear end of the filter, a first powder feeding pipeline is arranged on the ball mill discharge outlet of the vertical ball mill, a hot air blower of the vertical ball mill delivers hot air to the vertical ball mill and blows the dried silicon dioxide to the first powder feeding pipeline, the first powder feeding pipeline is connected to the upper part of a cyclone dust collector, a first bag collector is connected to the cyclone dust collector, a second powder feeding pipeline is connected to the cyclone dust collector, a tubular dust collector is connected to the second powder feeding pipeline, and a second bag collector is connected to the tubular dust collector. The device realizes comprehensive utilization of silicon-containing tailings, reduces environmental pollution, reduces dependence on natural silicon ore, relieves pressure on fluorite resources, and achieves multiple economic and social benefits.

Description

Technical Field

[0001] This utility model relates to silicon dioxide preparation technology, and more particularly to an apparatus for preparing high-purity silicon dioxide from silicon-containing tailings. Background Technology

[0002] Silicon-containing tailings are waste residues generated during metallurgical smelting processes. The composition of silicon-containing tailings is relatively complex, and the impurities they contain are mostly silicon-containing substances. These silicon-containing substances mainly exist in the form of silicon dioxide of different phases. They are usually suitable for producing bricks or other building materials, but the added value of the products is low. As a result, the silicon-containing substances are not effectively utilized. In fact, silicon-containing tailings are usually piled up in tailings ponds, which not only occupy a lot of land and prevents the rational use of silicon-containing tailings, but also causes environmental pollution and safety hazards to the surrounding areas.

[0003] Therefore, making full and comprehensive use of silicon-containing tailings resources has multiple economic and social benefits, such as reducing environmental pollution, alleviating dependence on natural silicon mines, extracting silicon-like substances from silicon-containing tailings to obtain ultrapure functional silicon dioxide, and relieving pressure on fluorite resources. Utility Model Content

[0004] To address the aforementioned problems, this utility model proposes an apparatus for preparing high-purity silica from silicon-containing tailings. The aim is to solve the problem of comprehensive utilization of existing silicon-containing tailings, reduce environmental pollution, and alleviate the pressure on fluorite resources.

[0005] This utility model is achieved through the following scheme: an apparatus for preparing high-purity silica from silicon-containing tailings, comprising an alkaline reactor and a settling tank connected to the alkaline reactor. The bottom of the settling tank is provided with a slag outlet and a liquid outlet. A flexible hose above the liquid surface of the settling tank is connected to the liquid outlet. The liquid outlet pipe is connected to an acid precipitation reactor. A filter is connected to the bottom pipe of the acid precipitation reactor. A vertical ball mill is provided at the rear end of the filter. The vertical ball mill includes a ball mill feed inlet and a ball mill discharge outlet. The silica filtered by the filter passes through the ball mill feed inlet. The ball mill is equipped with a first powder feeding pipe at its discharge port and a hot air blower at its bottom. The hot air blower supplies hot air to the ball mill and blows the dried silica to the first powder feeding pipe. The first powder feeding pipe is connected to the cyclone inlet of a cyclone dust collector. The cyclone dust collector has a first bag filter connected to its bottom hopper opening and a second powder feeding pipe connected to its upper cyclone outlet. The second powder feeding pipe is connected to a tubular dust collector, which is connected to a second bag filter.

[0006] Furthermore, the alkaline reaction vessel is equipped with an electric stirrer, and its stirring paddle is a spiral stirring paddle.

[0007] Furthermore, the alkaline reaction vessel is connected to a compressed air pipe.

[0008] Furthermore, a coil with air holes is installed on the inner bottom of the settling tank. The outside of the coil is connected to the compressed air pipe. Compressed air is introduced into the coil to the bottom of the settling tank. During the settling process of the alkaline solution obtained from the alkaline reactor, the alkaline solution is stirred by the compressed air. This not only prevents impurities from settling at the bottom of the settling tank and causing scaling, but also allows the silicates adsorbed in the impurities at the bottom to be fully dissolved and re-enter the alkaline solution.

[0009] Furthermore, a plate and frame filter press is installed at the slag outlet, and the filtrate outlet pipe of the plate and frame filter press is connected to the settling tank. The precipitated impurities that settle in the settling tank are periodically processed by the plate and frame filter press to obtain solid impurity residue. The filter water produced after filtration is pumped back into the settling tank through a pipeline connection. The dissolved sodium silicate solution in the filter water can thus be recycled back into the settling tank, while the precipitated impurities in the filter water undergo further settling.

[0010] Furthermore, a gauze filter is installed on the pipe between the liquid outlet and the acid precipitation vessel. The gauze filter further filters the precipitate before it enters the acid precipitation vessel, ensuring that the precipitate inside the vessel is clean and clear.

[0011] Furthermore, both the alkali reaction vessel and the acid precipitation vessel are equipped with heating jackets. The heating jackets can heat and maintain the temperature of the alkali reaction vessel or the acid precipitation vessel, thereby ensuring that the reaction can proceed better.

[0012] Furthermore, a vacuum pump is connected to the filter. By using the vacuum pump to evacuate the filter, the filtration speed can be accelerated and the filtration efficiency improved.

[0013] In this invention, pulverized silicon-containing tailings are added to an alkaline reactor through a feed port. Water or recycled wastewater is pumped in through a water inlet pipe. The water or recycled wastewater and silicon-containing tailings are stirred by a spiral agitator to obtain a slurry of silicon-containing tailings. A neutralizing agent containing additives such as sodium hydroxide, carbonates, and heavy metal scavengers is added through an alkali inlet pipe. The silicon-containing tailings react with the sodium hydroxide and carbonates in the neutralizing agent to form sodium silicate dissolved in the neutralizing agent. The heavy metal impurities in the silicon-containing tailings are chelated and precipitated or settled by the chelating effect of the heavy metal scavengers. The resulting alkaline solution is pumped into a settling tank through a bottom pipe of the alkaline reactor. To increase the discharge rate of the reaction slurry, pressure can be applied to the inside of the alkaline reactor using a compressed air pipe connected to the top of the reactor.

[0014] In this invention, the alkaline solution obtained from the alkaline reaction vessel is settled in a settling tank. A certain amount of flocculant is added to the settling tank to achieve rapid settling of the alkaline solution. The sodium silicate salt in the alkaline solution is better dissolved by the agitation of compressed air through a coil with vents installed at the bottom of the settling tank. After the sediment and alkaline solution are separated by the settling process, a clear settling liquid is obtained. The opening of the settling hose is controlled, and the clear settling liquid in the settling tank is pumped into an acid precipitation vessel through the settling hose. The precipitated impurities in the settling tank are filtered by a plate and frame filter press, and the filtrate is returned to the settling tank. The filter cake is used to produce bricks or other building materials.

[0015] In this invention, hydrochloric acid solution is added to an acid precipitation vessel. Under the action of hydrochloric acid, the pH value of the sediment in the acid precipitation vessel gradually decreases. When the pH value of the sediment is acidic, the silicates in the sediment are hydrolyzed to obtain silica precipitate. The obtained silica precipitate is then filtered through a vacuum filter. During the filtration process, the silica precipitate is washed with water until neutralized to obtain high-purity silica wet material.

[0016] In this invention, a vertical ball mill can grind filtered silica and simultaneously dry it under the action of a hot air blower. The ground silica is fed into a first powder feeding pipe by the hot air blower. After the silica is cooled and dehumidified by the first powder feeding pipe, it enters a cyclone separator for cyclone separation. The functional silica obtained by the cyclone separator is collected by a first bag collector. The silica that fails to settle and separate in the cyclone separator enters a second powder feeding pipe through the cyclone outlet of the cyclone separator, and is further captured by a tubular dust collector. The resulting nano-sized functional ultrapure silica is collected by a second bag collector.

[0017] This invention obtains high-purity wet silica from silicon-containing tailings through alkaline dissolution, sedimentation filtration, and acid precipitation filtration. The high-purity wet silica is then ground in a vertical ball mill and separated into functional silica using a cyclone separator. Finally, nanoscale functional ultrapure silica is captured by a tubular dust collector. This invention achieves comprehensive utilization of silicon-containing tailings, reduces environmental pollution, lessens dependence on natural silicon mines, and alleviates pressure on fluorite resources, thus achieving multiple economic and social benefits. Attached Figure Description

[0018] Figure 1 A schematic diagram of an apparatus for preparing high-purity silica from silicon-containing tailings.

[0019] Among them: 1-alkali reaction vessel, 2-water addition pipe, 3-alkali addition pipe, 4-compressed air pipe, 5-feeding port, 6-sedimentation tank, 61-slag outlet, 62-liquid outlet, 7-coil, 8-flexible hose, 9-plate and frame filter press, 10-gauze filter, 11-acid precipitation vessel, 12-acid addition pipe, 13-filter, 14-vacuum pump, 15-vertical ball mill, 151-ball mill feed port, 152-ball mill discharge port, 153-hot air blower, 16-first powder feeding pipe, 17-cyclone dust collector, 171-cyclone inlet, 172-cyclone outlet, 173-hopper opening, 18-first bag collector, 19-second powder feeding pipe, 20-tubular dust collector, 21-second bag collector. Detailed Implementation

[0020] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0021] An apparatus for preparing high-purity silica from silicon-containing tailings, such as... Figure 1 The reaction vessel includes an alkali reactor 1 and a settling tank 6 connected to the alkali reactor 1. The alkali reactor 1 is connected to a water inlet pipe 2 and an alkali inlet pipe 3. The alkali reactor 1 is equipped with an electric stirrer, and its stirring paddle is a spiral stirrer. Crushed silicon-containing tailings are added to the alkali reactor 1 through the feed port 5. Water or recycled wastewater is pumped into the alkali reactor 1 through the water inlet pipe 2. The water or recycled wastewater and the silicon-containing tailings are stirred by the spiral stirrer to obtain a slurry of silicon-containing tailings. Then, a neutralizing agent containing additives such as sodium hydroxide, carbonates, and heavy metal scavengers is added through the alkali inlet pipe 3. After the tailings are reacted, the silicon-containing substances react with the sodium hydroxide and carbonate in the neutralizing agent to obtain sodium silicate dissolved in the neutralizing agent. The heavy metal impurities in the silicon-containing tailings are chelated and precipitated or settled under the chelating action of the heavy metal capture agent. The resulting alkaline solution is pumped into the settling tank 6 through the bottom pipe of the alkaline reactor 1. In order to increase the discharge speed of the reaction slurry, the compressed air pipe 4 connected to the top of the alkaline reactor 1 can be used to apply pressure to the inside of the alkaline reactor 1, thereby pumping the alkaline solution in the alkaline reactor 1 into the settling tank 6.

[0022] The bottom of the settling tank 6 is equipped with a slag outlet 61 and a liquid outlet 62. A flexible hose 8, higher than the liquid surface in the settling tank 6, is connected to the liquid outlet 62. The hose of the liquid outlet 62 is connected to an acid precipitation vessel 11. A coil 7 with vents is installed inside the bottom of the settling tank 6. The outside of the coil 7 is connected to a compressed air pipe 4. A plate and frame filter press 9 is installed on the slag outlet 61 of the settling tank 6. The filtrate outlet pipe of the plate and frame filter press 9 is connected to the settling tank 6. By adding a certain amount of flocculant to the settling tank 6, the reaction alkaline solution is rapidly settled in the settling tank 6. The vents installed at the bottom of the settling tank 6 are utilized to achieve this. The agitation of compressed air in coil 7 allows the sodium silicate in the reaction alkaline solution to dissolve better, preventing impurities from settling at the bottom of settling tank 6 and causing scaling. After standing for 4-8 hours, settling is achieved, and the precipitate is separated from the reaction alkaline solution. The clarified settling liquid is then pumped into acid precipitation tank 11 through flexible hose 8, controlling the opening of flexible hose 8. The precipitated impurities in settling tank 6 are filtered by plate and frame filter press 9, and the filtrate is returned to settling tank 6. The filter cake is used to produce bricks or other building materials.

[0023] An acid precipitation vessel 11 is equipped with an acid addition pipe 12. To ensure that the sediment in the acid precipitation vessel 11 is clean and clear, a gauze filter 10 is also installed on the pipe between the outlet 62 and the acid precipitation vessel 11. The sediment is further filtered by the gauze filter 10 to obtain a clean and clear sediment. Hydrochloric acid solution is added to the acid precipitation vessel 11 through the acid addition pipe 12. Under stirring conditions, the pH value of the sediment in the acid precipitation vessel 11 gradually decreases under the action of hydrochloric acid. When the pH value of the sediment is acidic, the silicate in the sediment is hydrolyzed to obtain silica precipitate. The silica precipitate and the solution after the reaction are completed are filtered by the filter 13. In order to accelerate the filtration speed of the filter 13 and improve the filtration efficiency, a vacuum pump 14 is connected to the filter 13 to realize vacuum filtration. During the filtration process of the filter 13, the silica precipitate is washed with water until neutralized to obtain high-purity silica wet material.

[0024] A vertical ball mill 15 is located at the rear end of the filter 13. The vertical ball mill 15 includes a ball mill inlet 151 and a ball mill outlet 152. Silica filtered by the filter 13 is fed through the ball mill inlet 151. A first powder feeding pipe 16 is provided on the ball mill outlet 152. A hot air blower 153 is located at the bottom of the vertical ball mill 15. The hot air blower 153 supplies hot air to the vertical ball mill 15 and blows the dried silica to the first powder feeding pipe 16. The first powder feeding pipe 16 cools and dehumidifies the silica. The first powder feeding pipe 16 is connected to the cyclone inlet 171 of the cyclone dust collector 17. 7. A first bag collector 18 is connected to the hopper opening 173 at the bottom. Silica is separated by the cyclone separator 17 to obtain functional silica, which is then collected by the first bag collector 18. The cyclone outlet 172 at the top of the cyclone dust collector 17 is connected to a second powder feeding pipe 19. A tubular dust collector 20 is connected to the second powder feeding pipe 19. The tubular dust collector 20 is connected to a second bag collector 21. The tubular dust collector 20 further captures the remaining small-molecule silica inside the air supply to obtain nano-sized functional ultrapure silica, which is then collected by the second bag collector 21.

[0025] In a further embodiment, both the alkali reaction vessel 1 and the acid precipitation vessel 11 are equipped with heating jackets, which can heat and keep the alkali reaction vessel 1 or the acid precipitation vessel 11, thereby ensuring that the reaction can proceed better.

[0026] The above embodiments merely illustrate the implementation of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An apparatus for preparing high-purity silica from silicon-containing tailings, characterized in that: The apparatus includes an alkali reaction vessel and a settling tank connected to the alkali reaction vessel. The bottom of the settling tank has a slag outlet and a liquid outlet. A flexible hose, higher than the liquid surface in the settling tank, is connected to the liquid outlet. An acid precipitation vessel is connected to the bottom of the acid precipitation vessel via a pipe. A filter is connected to the rear end of the filter via a vertical ball mill. The vertical ball mill includes a ball mill inlet and a ball mill outlet. Silica filtered by the filter is fed into the ball mill through the ball mill inlet. A first powder feeding device is provided at the ball mill outlet. The vertical ball mill is equipped with a hot air blower at its bottom. The hot air blower supplies hot air to the vertical ball mill and blows the dried silica to the first powder feeding pipe. The first powder feeding pipe is connected to the cyclone inlet of a cyclone dust collector. The cyclone dust collector has a first bag filter connected to the hopper opening at its bottom. The cyclone dust collector has a second powder feeding pipe connected to the cyclone outlet at its top. The second powder feeding pipe is connected to a tubular dust collector, which is connected to a second bag filter.

2. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: The alkaline reaction vessel is equipped with an electric stirrer, and its stirring paddle is a spiral stirring paddle.

3. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: The alkaline reaction vessel is connected to a compressed air pipe.

4. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 3, characterized in that: A coil with air holes is installed on the inner bottom of the settling tank, and the outside of the coil is connected to the compressed air pipe.

5. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: A plate and frame filter press is installed at the slag outlet, and the filtrate outlet pipe of the plate and frame filter press is connected to the settling tank.

6. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: A gauze filter is also installed on the pipeline between the liquid outlet and the acid precipitation vessel.

7. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: Both the alkali reaction vessel and the acid precipitation vessel are equipped with heating jackets.

8. The apparatus for preparing high-purity silica from silicon-containing tailings according to claim 1, characterized in that: A vacuum pump is connected to the filter.

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