An apparatus for the production of zinc oxide by suspension calcination

Abstract

The utility model discloses a device of preparation zinc oxide of suspension calcination, it device of preparation zinc oxide of suspension calcination contains feeding hopper, rotary kiln and cooling machine, the kiln head of cooling machine with rotary kiln is connected, the kiln tail of rotary kiln is connected with the lower extreme of suspension calcining furnace, the lower part of suspension calcining furnace is provided with suspension combustor and suspension blower respectively, the upper end of suspension calcining furnace is connected with the import of cyclone dust collector, the export of cyclone dust collector is connected with bag type dust collector, the material export of feeding hopper is connected with the kiln tail of rotary kiln. The utility model is through reducing zinc first and then oxidizing zinc, makes full use of the low boiling point physical property of zinc, can handle the material of lower zinc content, and the zinc steam is oxidized in suspension kiln, and zinc and oxygen contact more fully, and the particle size of the separated zinc oxide is smaller.

Description

Technical Field

[0001] This utility model relates to a zinc oxide preparation technology, and in particular to an apparatus for preparing zinc oxide by suspension roasting. Background Technology

[0002] Zinc oxide is an oxide of zinc. It is sparingly soluble in water but soluble in acids and strong alkalis. Zinc oxide is a commonly used chemical additive, widely used in the manufacture of plastics, silicate products, synthetic rubber, lubricants, paints, coatings, ointments, adhesives, food, batteries, flame retardants, and other products. Zinc oxide has a large band gap and exciton binding energy, high transparency, and excellent room-temperature luminescence properties, making it used in semiconductor products such as liquid crystal displays, thin-film transistors, and light-emitting diodes. With global zinc concentrate production declining and recycled zinc production capacity limited, the extraction of zinc from lean ores and from waste materials has become an increasingly important focus.

[0003] Application publication number CN119321685A discloses a production process and apparatus for zinc calcined ore, comprising a hollow decomposition furnace, a rotary kiln connected to the bottom of the decomposition furnace, a three-way valve connected to the upper end of the decomposition furnace, the decomposition furnace tapering at both ends, a burner installed at the lower end of the decomposition furnace, one end of the three-way valve connected to a fifth calcination cyclone separator, and the other end of the three-way valve connected to an outer pipe of a carbonization furnace. The carbonization furnace consists of multiple carbonization flue gas pipes installed inside a flue gas pipe. The upper part of the three-way valve, away from the fifth calcination cyclone separator, is tangentially connected to the outer pipe of the carbonization furnace, and the other ends of the multiple carbonization pipes are connected to the lower end of the decomposition furnace. This application has the effect of reducing production costs by using the flue gas from the rotary kiln production of zinc calcined ore as a heat source and utilizing a multi-stage calcination cyclone separator to calcine the zinc calcined ore to obtain the product zinc calcined ore.

[0004] However, the above-mentioned patented technology has some problems: first, the use of a decomposition furnace results in poor roasting effect; second, the filtration and separation effect is poor. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of existing calibration technology and provide a device for preparing zinc oxide by suspension roasting with reasonable design, good roasting effect and high conversion rate.

[0006] The technical solution of this utility model is:

[0007] An apparatus for preparing zinc oxide by suspension roasting includes a feeding hopper, a rotary kiln, and a cooler. The cooler is connected to the kiln head of the rotary kiln, and the kiln tail of the rotary kiln is connected to the lower end of the suspension roasting furnace. The lower part of the suspension roasting furnace is equipped with a suspension burner and a suspension blower. The upper end of the suspension roasting furnace is connected to the inlet of a cyclone dust collector, and the outlet of the cyclone dust collector is connected to a bag filter. The material outlet of the feeding hopper is connected to the kiln tail of the rotary kiln.

[0008] Furthermore: there is one or more cyclone dust collectors. When there are multiple cyclone dust collectors, they are connected in series.

[0009] Furthermore: the suspension burner injects a high-temperature flame into the suspension roasting furnace through a combustion pipe to heat the gas inside the furnace and increase the furnace temperature; the suspension blower can blow air into the suspension roasting furnace, so that the material entering the suspension roasting furnace is in a suspended state, and the high-temperature gas inside the furnace transfers the heat generated by the burner to the material, and the material undergoes suspension roasting oxidation.

[0010] Furthermore, the suspension roasting furnace is equipped with an oxygen content detector, which controls the air volume of the suspension blower.

[0011] Furthermore: the rotary kiln is equipped with a rotary kiln burner, which heats the gas inside the kiln and increases the temperature inside the kiln. The material is conveyed from the kiln tail to the kiln head for roasting and reduction. Then, the material roasted by the rotary kiln is conveyed to the cooler for cooling treatment. The reduced zinc vapor enters the suspension roasting furnace from the rotary kiln.

[0012] Furthermore, the cooler is a single-cylinder cooler. The material enters the cooler from the rotary kiln for heat exchange. After the material is cooled, it is discharged from the cooler. The heated air enters the rotary kiln as secondary air to support combustion.

[0013] Furthermore: Under the action of the fan, the gas enters the cyclone dust collector from the suspension roasting furnace. The outer wall of the cyclone dust collector is equipped with a jacketed water system, which cools the gas and allows the waste heat to be used for power generation. The coarser powder is discharged from the cyclone dust collector, while the finer zinc oxide powder is discharged from the bag filter.

[0014] The beneficial effects of this utility model are:

[0015] 1. This utility model reduces zinc in materials by calcining in a rotary kiln. Zinc vapor and exhaust gas are then fed into a suspension roasting furnace for roasting and oxidation, which removes toxic and harmful components from the exhaust gas and precipitates zinc oxide crystals. Oxidizing zinc oxide and roasting it in a suspension furnace makes it easier to obtain pure zinc oxide without producing gas pollution or waste.

[0016] 2. This utility model fully utilizes the low boiling point property of zinc by first reducing zinc and then oxidizing it, which can process materials with low zinc content. The zinc vapor is oxidized in the suspension kiln, and the zinc and oxygen are in more complete contact, resulting in smaller zinc oxide particles.

[0017] 3. This utility model makes zinc material, carbon, and sodium fluoride into pellets, which are less prone to volatile dust on the surface, resulting in higher quality zinc oxide products. The pellets can also be sold as ceramsite without generating waste.

[0018] 4. The air introduced into the cooler of this utility model can enter the rotary kiln as secondary air to support combustion, saving energy. In addition, the water in the jacket of the cyclone dust collector forms steam for power generation and steaming of the feed balls. The CO generated during the zinc reduction process is used for combustion in the suspension furnace. The whole process is green, pollution-free and energy-saving.

[0019] 5. This utility model has a reasonable design, good roasting effect and high conversion rate, while improving production efficiency. It can also handle a large volume through a rotary kiln, enabling industrial-scale production. It is easy to promote and implement, and has good economic benefits. Attached Figure Description

[0020] Figure 1 A schematic diagram of an apparatus for preparing zinc oxide by suspension roasting;

[0021] Figure 2 A process flow diagram of an apparatus for preparing zinc oxide by suspension roasting. Detailed Implementation

[0022] Example: See Figure 1 -- Figure 2 In the diagram, 11-feeding hopper, 21-rotary kiln, 22-rotary kiln burner, 31-cooler, 41-suspension roasting furnace, 42-suspension burner, 43-suspension blower, 51-primary cyclone dust collector, 52-secondary cyclone dust collector, 61-bag dust collector.

[0023] An apparatus for preparing zinc oxide by suspension roasting includes a feeding hopper 11, a rotary kiln 21, a cooler 31, a suspension roasting furnace 41, and a powder recovery mechanism connected in sequence, wherein:

[0024] Rotary kiln 21 is equipped with a rotary kiln burner 22. When the rotary kiln 21 is started, it transports the material from the kiln tail to the kiln head for roasting and reduction. The material roasted in the rotary kiln 21 is then transported to a cooling furnace 31 for cooling treatment. The reduced zinc vapor enters the suspension roasting furnace 41 from the tail of the rotary kiln 21. The rotary kiln burner 22 heats the gas inside the kiln, increasing the kiln temperature. The rotary kiln burner 22 uses natural gas or similar fuels to avoid using fuels that produce fly ash.

[0025] Cooler 31 is a single-cylinder cooler. The cooling of the material is completed during the process of the material balls entering and exiting the cooler 31, and the air is heated to a certain temperature and enters the rotary kiln 21 as secondary air to support combustion.

[0026] The suspension furnace 41 is equipped with an oxygen content detector (not shown in the figure). The suspension blower blows oxygen-enriched air into the furnace, and the air volume of the suspension blower is controlled by the oxygen content detector.

[0027] The dust collection mechanism includes two-stage cyclone dust collectors 51-52, a bag filter 61, and a fan. The fan draws gas from the suspension roasting furnace 41 into the cyclone dust collectors 51-52. The outer wall of the cyclone dust collectors 51-51 has a water jacket to cool the gas, and the waste heat can be used to generate electricity. The coarser powder is discharged from the cyclone dust collectors 51-51, while the finer zinc oxide powder is discharged from the bag filter 61.

[0028] The working process of an apparatus for preparing zinc oxide by suspension roasting includes the following steps:

[0029] Step 1: Mix and grind the zinc-containing raw materials, carbonaceous reducing agent and sodium fluoride additive to form 5-15 mm pellets.

[0030] Step 2 involves drying the material balls and then curing them in an autoclave, which makes it less likely for the surface of the material balls to shed powder.

[0031] Step 3: Feed the material balls into the feeding hopper 11, and after quantitative metering, feed them into the rotary kiln 21.

[0032] Step 4: Ignite the rotary kiln burner 22 to heat the rotary kiln 21 to 1100-1300℃. The zinc in the feed pellets is reduced and forms zinc vapor. The zinc vapor enters the suspension roasting kiln 41 from the tail of the rotary kiln 21, while the feed pellets enter the cooler 31 from the head of the rotary kiln 21.

[0033] After the material balls are discharged from the cooler 31 in step 5, they are packaged and bagged for sale.

[0034] Step 6: Zinc vapor enters the suspension roasting furnace 41, along with some CO. The suspension roasting furnace 41 is ignited by the suspension burner 42, and oxygen-enriched air is introduced. The airflow of the suspension blower 43 is adjusted by the oxygen content detector at the top of the suspension roasting furnace. The temperature of the suspension roasting furnace 41 is maintained at 700-900℃, and the residence time is 1-2 minutes. The zinc vapor is rapidly oxidized into zinc oxide, and CO is oxidized into CO2 as fuel.

[0035] In step 7, after the zinc oxide enters the two-stage cyclone dust collectors 51-52, it is cooled to 100-200℃. The jacket water on the surface of the cyclone dust collectors 51-52 is heated into steam. The collected steam is used for power generation and steaming the feed pellets. Meanwhile, the coarser zinc oxide and dust are discharged from the bottom of the cyclone dust collectors 51-52 and collected.

[0036] In step 8, the finer zinc oxide powder cannot be removed by the cyclone dust collectors 51-52, so it enters the bag dust collector 61 where it is filtered and collected. The exhaust gas is then treated and discharged into the atmosphere.

[0037] It should be noted that the models and quantities of blowers, burners, etc., can be adjusted according to actual working conditions, and the number of stages of cyclone dust collectors can be increased according to actual working conditions.

[0038] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications made based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. An apparatus for preparing zinc oxide by suspension roasting, comprising a feeding hopper, a rotary kiln, and a cooler, wherein the cooler is connected to the kiln head of the rotary kiln, characterized in that: The kiln tail of the rotary kiln is connected to the lower end of the suspension roasting furnace. The lower part of the suspension roasting furnace is equipped with a suspension burner and a suspension blower. The upper end of the suspension roasting furnace is connected to the inlet of a cyclone dust collector. The outlet of the cyclone dust collector is connected to a bag filter. The material outlet of the feeding hopper is connected to the kiln tail of the rotary kiln.

2. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: The cyclone dust collector is one or more. When there are multiple cyclone dust collectors, they are connected in series.

3. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: The suspension burner injects a high-temperature flame into the suspension roasting furnace through a combustion pipe to heat the gas inside the furnace and increase the furnace temperature; the suspension blower can blow air into the suspension roasting furnace, so that the material entering the suspension roasting furnace is in a suspended state, and the high-temperature gas inside the furnace transfers the heat generated by the burner to the material, and the material undergoes suspension roasting oxidation.

4. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: The suspension roasting furnace is equipped with an oxygen content detector, which controls the air volume of the suspension blower.

5. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: The rotary kiln is equipped with a rotary kiln burner, which heats the gas inside the kiln and increases the temperature inside the kiln. The material is conveyed from the kiln tail to the kiln head for roasting and reduction. The material after roasting in the rotary kiln is then conveyed to the cooler for cooling treatment. The reduced zinc vapor enters the suspension roasting furnace from the rotary kiln.

6. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: The cooler is a single-cylinder cooler. The material enters the cooler from the rotary kiln for heat exchange. After the material is cooled, it is discharged from the cooler. The heated air enters the rotary kiln as secondary air to support combustion.

7. The apparatus for preparing zinc oxide by suspension roasting according to claim 1, characterized in that: Under the action of the fan, the gas enters the cyclone dust collector from the suspension roasting furnace. The outer wall of the cyclone dust collector is equipped with a jacketed water system to cool the gas. The waste heat can be used to generate electricity. The coarser powder is discharged from the cyclone dust collector, while the finer zinc oxide powder is discharged from the bag dust collector.

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