An apparatus for the suspension roasting of zinc concentrates

Abstract

The utility model discloses a device of suspension roasting treatment zinc concentrate, it contains feeding hopper, rotary kiln and grate cooler, the grate cooler with the kiln head of rotary kiln is connected, the lower part of grate cooler is provided with the air -blower, and the kiln tail of rotary kiln is connected with the lower extreme of suspension roasting furnace, and the lower part of suspension roasting furnace is provided with suspension burner and suspension air -blower respectively, and the upper end of suspension roasting furnace is connected with the import of gas -solid cyclone, and the air -outlet of gas -solid cyclone is connected with the lower extreme of feeding hopper through preheating mechanism, and the material outlet of gas -solid cyclone is connected with the kiln tail of rotary kiln. The utility model not only guarantees the more optimal oxidation rate, but also avoids the sintering into big piece caused by the long roasting time of material in rotary kiln, and the comprehensive roasting oxidation time is significantly less than traditional oxidation mode, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to a zinc concentrate processing technology, and in particular to a device for suspension roasting zinc concentrate. Background Technology

[0002] In the zinc smelting process, zinc ore is beneficiated to obtain zinc concentrate. Zinc concentrate must be roasted to obtain zinc oxide in order to facilitate subsequent smelting into zinc. This requires that the zinc concentrate be fully roasted in the pretreatment stage to convert zinc concentrate such as sphalerite or smithsonite into zinc oxide as much as possible.

[0003] Traditional roasting methods (such as rotary kiln roasting) have the following problems: high energy consumption: low efficiency of material contact with heat source and insufficient heat utilization; uneven reaction: material accumulation leads to local over-burning or under-burning; although fluidized bed roasting can improve heat transfer efficiency, the residence time is not easy to control, resulting in large fluctuations in zinc oxide conversion rate. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of existing calibration technology and provide a device for suspension roasting of zinc concentrate that is reasonably designed, has low energy consumption and high conversion rate.

[0005] The technical solution of this utility model is:

[0006] An apparatus for suspension roasting zinc concentrate includes a feeding hopper, a rotary kiln, and a grate cooler. The grate cooler is connected to the kiln head of the rotary kiln, and a blower is installed at the lower part of the grate cooler. The kiln tail of the rotary kiln is connected to the lower end of a suspension roasting furnace. A suspension burner and a suspension blower are respectively installed at the lower part of the suspension roasting furnace. The upper end of the suspension roasting furnace is connected to the inlet of a gas-solid cyclone separator. The air outlet of the gas-solid cyclone separator is connected to the lower end of the feeding hopper through a preheating mechanism. The material outlet of the gas-solid cyclone separator is connected to the kiln tail of the rotary kiln.

[0007] Furthermore, the preheating mechanism includes a three-stage cyclone preheater, wherein the lower material outlet of the feeding hopper is connected to the inlet of the first-stage cyclone preheater and the air outlet of the second-stage cyclone preheater, respectively; the material outlet of the first-stage cyclone preheater is connected to the inlet of the second-stage cyclone preheater and the air outlet of the third-stage cyclone preheater, respectively; the material outlet of the second-stage cyclone preheater is connected to the inlet of the third-stage cyclone preheater and the air outlet of the cyclone gas-solid separator, respectively; and the material outlet of the third-stage cyclone preheater is connected to the narrow opening at the bottom of the suspension roasting furnace.

[0008] Furthermore: the suspension burner injects high-temperature flames into the suspension roasting furnace through the combustion pipe to heat the gas inside the furnace and increase the furnace temperature; the air inlet of the suspension blower is connected to the tertiary air supply pipe, which can blow air into the suspension roasting furnace, so that the zinc concentrate entering the suspension roasting furnace is in a suspended state, and the high-temperature gas in the furnace transfers the heat generated by the burner to the material, and the material undergoes suspension roasting oxidation.

[0009] Furthermore, the upper and lower parts of the suspension roasting furnace are both Venturi nozzle-type, which makes it less likely for materials to clog at the inlet and outlet.

[0010] Furthermore, the rotary kiln is characterized by having a rotary kiln burner, which heats the gas inside the kiln and raises the temperature inside the kiln. The zinc concentrate is transported from the kiln tail to the kiln head for roasting and oxidation, and the roasted and oxidized zinc concentrate is then transported to the grate cooler for cooling.

[0011] Furthermore: the material discharged from the rotary kiln enters the inlet of the grate cooler, the blower blows air into the grate cooler, the material and the gas exchange heat, and the cooled material is discharged from the outlet of the grate cooler to obtain the product; the hot air after heat exchange enters the rotary kiln and the cyclone blower respectively to serve as secondary air and tertiary air.

[0012] The beneficial effects of this utility model are:

[0013] 1. This utility model ensures a better oxidation rate while avoiding the sintering of materials into large lumps due to long roasting time in the rotary kiln. The overall roasting and oxidation time is significantly less than that of traditional oxidation methods, thus improving production efficiency.

[0014] 2. This utility model enables zinc concentrate to undergo two oxidation processes: suspension roasting oxidation and rotary kiln roasting oxidation. Compared to single oxidation, even zinc concentrate materials that fail to be oxidized during suspension roasting can be oxidized in the subsequent rotary kiln body. This ensures the oxidation rate of the method while saving energy and improving efficiency.

[0015] 3. This utility model firstly converts zinc concentrate into zinc oxide in a very short time through a highly efficient pre-suspended roasting oxidation system, and then performs a secondary conversion of zinc concentrate through a rotary kiln roasting system. Compared with the traditional oxidation method that only uses rotary kiln roasting, this method has high heat transfer efficiency and saves fuel.

[0016] 4. This utility model uses a burner to heat the gas inside the suspension roasting furnace and a blower to blow air into the furnace. The material is fully dispersed inside the furnace, and each small piece of zinc concentrate is surrounded by high-temperature gas. The heat transfer area is large and the heat conduction is fast, which can transfer the heat of combustion to the material in a timely manner. The heat transfer efficiency is high, saving fuel and roasting time. Most of the zinc concentrate entering the rotary kiln has already begun to oxidize. The rotary kiln only needs to maintain the kiln temperature to oxidize the remaining zinc concentrate. By controlling the residence time of the rotary kiln roasting, the probability of sintering is reduced. The material itself has a high kiln entry temperature, which further saves the energy consumption of rotary kiln roasting.

[0017] 5. This utility model has a reasonable design, low energy consumption and high conversion rate, while improving production efficiency, easy to promote and implement, and good economic benefits. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a device for suspension roasting zinc concentrate.

[0019] Figure 2 This is a process flow diagram of an apparatus for suspension roasting zinc concentrate. Detailed Implementation

[0020] Example: See Figure 1 -- Figure 2 In the diagram, 11-feeding hopper, 21-primary cyclone separator, 22-secondary cyclone separator, 23-tertiary cyclone separator, 24-gas-solid cyclone separator, 31-suspension roasting furnace, 32-suspension burner, 33-blower, 41-rotary kiln, 42-rotary kiln burner, 51-grate cooler, 52-blower.

[0021] An apparatus for suspension roasting zinc concentrate includes a preheating mechanism, a suspension roasting mechanism, a rotary kiln roasting mechanism, and a cooling mechanism connected in sequence, wherein:

[0022] The preheating mechanism includes a feeding hopper 11 and a multi-stage cyclone preheater. The material outlet of the feeding hopper 11 is connected to the inlet of the first-stage cyclone preheater 21 and the air outlet of the second-stage cyclone preheater 22. The material outlet of the first-stage cyclone preheater 21 is connected to the inlet of the second-stage cyclone preheater 22 and the air outlet of the third-stage cyclone preheater 23. The material outlet of the second-stage cyclone preheater 22 is connected to the inlet of the third-stage cyclone preheater 23 and the air outlet of the cyclone gas-solid separator 24. The material outlet of the third-stage cyclone preheater 23 is connected to the narrow opening at the bottom of the suspension roasting furnace 31. The material outlet of the cyclone gas-solid separator 24 is connected to the tail end 41 of the rotary kiln.

[0023] The suspension roasting mechanism includes a suspension roasting furnace 31, a burner 32, and a blower 33. The top of the suspension roasting furnace 31 is connected to a gas-solid cyclone separator 24. The suspension burner 32 injects a high-temperature flame into the suspension roasting furnace 31 through a combustion pipe to heat the gas inside the furnace and increase the furnace temperature. The air inlet of the blower 33 is connected to a tertiary air supply pipe, and the other end is connected to the suspension roasting furnace 31. The blower 32 blows air into the suspension roasting furnace, keeping the zinc concentrate material entering the suspension roasting furnace 31 in a suspended state. The high-temperature gas inside the furnace transfers the heat generated by the burner to the material, and the material undergoes suspension roasting oxidation. The opening and closing of the suspension burner 32, the size and direction of the flame, and the opening and closing of the blower, the air force, and the air direction can be adaptively adjusted according to the actual working conditions. The bottom of the suspension roasting furnace 31 is connected to the tail of the rotary kiln 41. The upper and lower parts of the suspension roasting furnace 31 are shaped like Venturi nozzles, which prevents the material from clogging at the inlet and outlet.

[0024] The rotary kiln roasting and oxidation mechanism includes a rotary kiln body 41 and a rotary kiln burner 42. The kiln tail of the rotary kiln body 41 is connected to the suspension roasting furnace 31, and the kiln head is connected to the cooling mechanism. The rotary kiln burner 42 heats the gas inside the rotary kiln body, increasing the kiln temperature. The zinc concentrate is transported from the kiln tail to the kiln head for roasting and oxidation. The roasted and oxidized zinc concentrate is then transported to the cooling mechanism for cooling.

[0025] The cooling mechanism includes a grate cooler 51 and a blower 52. The grate cooler 51 is connected to the head of the rotary kiln 41, and the blower 52 blows air from the bottom. The material enters from the inlet of the grate cooler 51, is cooled, and is discharged from the outlet to obtain the product. After heat exchange between the gas and the material, the gas enters the rotary kiln 41 and the suspension kiln 31 to serve as secondary and tertiary air, respectively.

[0026] The working process of an apparatus for suspension roasting zinc concentrate includes the following steps:

[0027] Step 1: Zinc Concentrate Preheating Treatment: The zinc concentrate is conveyed to the feeding hopper 11. The material, along with the hot air from the secondary cyclone preheater 22, enters the primary cyclone preheater 21. After heat exchange in the primary cyclone preheater 21, the exhaust gas is cooled to approximately 200°C and finally discharged from the top of the primary cyclone preheater 21. After treatment, it is released into the atmosphere. The material, heated to 200°C, flows out from the bottom of the primary cyclone preheater 21 and enters the secondary cyclone preheater 22 along with the air pipe of the tertiary cyclone preheater 23. In this stage, the exhaust gas is cooled to 400–500°C, and the material is heated to 400–500°C. The material from the secondary cyclone preheater 22, along with the gas from the gas-solid cyclone separator 24, enters the tertiary cyclone preheater 23. The material is heated to 700–800°C, and the gas is cooled to 700–800°C.

[0028] Step 2: Suspension roasting oxidation: The zinc concentrate material preheated in Step 1 is conveyed to the bottom of the suspension roasting furnace 31. The burner 32 injects flames into the suspension roasting furnace 31 through the combustion pipe, raising the temperature of the gas inside the furnace. The blower 33 blows air into the suspension roasting furnace, and the zinc concentrate material is fully dispersed in the furnace and is in a suspended state, surrounded by the high-temperature gas inside the furnace. The temperature inside the furnace is raised to 900-1000℃, and the zinc concentrate begins to be converted into zinc oxide. The residence time is 1-2 minutes. The suspended material and gas enter the gas-solid cyclone separator 24 together. The gas enters the three-stage preheater 23, and the solid enters the rotary kiln 41 for further heat preservation and conversion into zinc oxide.

[0029] Step 3 Rotary kiln calcination oxidation: After the material obtained in step 2 is fully heated to the temperature required for oxidation, it is necessary to maintain the reaction for a certain period of time. The material enters from the tail of rotary kiln 41, and the temperature of rotary kiln 41 is maintained at 1000-1100℃. It slowly flows out from the head of rotary kiln 41, and the residence time is about 20-40 minutes.

[0030] Step 4: Cooling treatment of zinc concentrate material: Zinc oxide enters the grate cooler 51 from the rotary kiln 41. Air is blown into the bottom of the grate cooler 51, and the zinc oxide material is cooled to about 80°C. The heated air is used as the secondary and tertiary air of the burner.

[0031] 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 suspension roasting of zinc concentrate, comprising a feeding hopper, a rotary kiln, and a grate cooler, wherein the grate cooler is connected to the kiln head of the rotary kiln, and a blower is provided at the lower part of the grate cooler, 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 the gas-solid cyclone separator. The air outlet of the gas-solid cyclone separator is connected to the lower end of the feeding hopper through a preheating mechanism. The material outlet of the gas-solid cyclone separator is connected to the kiln tail of the rotary kiln.

2. The apparatus for suspension roasting zinc concentrate according to claim 1, characterized in that: The preheating mechanism includes a three-stage cyclone preheater. The lower material outlet of the feeding hopper is connected to the inlet of the first-stage cyclone preheater and the outlet of the second-stage cyclone preheater. The material outlet of the first-stage cyclone preheater is connected to the inlet of the second-stage cyclone preheater and the outlet of the third-stage cyclone preheater. The material outlet of the second-stage cyclone preheater is connected to the inlet of the third-stage cyclone preheater and the outlet of the cyclone gas-solid separator. The material outlet of the third-stage cyclone preheater is connected to the narrow opening at the bottom of the suspension roasting furnace.

3. The apparatus for suspension roasting zinc concentrate 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 air inlet of the suspension blower is connected to the tertiary air supply pipe, which can blow air into the suspension roasting furnace, so that the zinc concentrate entering the suspension roasting furnace is in a suspended state. The high-temperature gas in the furnace transfers the heat generated by the burner to the material, and the material undergoes suspension roasting and oxidation.

4. The apparatus for suspension roasting zinc concentrate according to claim 1, characterized in that: The upper and lower parts of the suspension roasting furnace are both Venturi nozzle-type, which makes it less likely for materials to clog at the inlet and outlet.

5. The apparatus for suspension roasting zinc concentrate 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 zinc concentrate is transported from the kiln tail to the kiln head for roasting and oxidation. The zinc concentrate that has been roasted and oxidized in the rotary kiln is then transported to the grate cooler for cooling.

6. The apparatus for suspension roasting zinc concentrate according to claim 1, characterized in that: The material discharged from the rotary kiln enters the inlet of the grate cooler, and the blower blows air into the grate cooler. The material and the gas exchange heat, and the cooled material is discharged from the outlet of the grate cooler to obtain the product. The hot air after heat exchange enters the rotary kiln and the cyclone blower respectively to serve as secondary air and tertiary air.

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