阅读说明：本技术 锂矿石隧道窑焙烧方法及装置 (Lithium ore tunnel kiln roasting method and device ) 是由 南进喜 吴进方 苏捷 王家前 曾小毛 张颖 于 2021-09-02 设计创作，主要内容包括：本发明就是要提供一种锂矿石隧道窑焙烧提锂方法及装置,是以锂矿石为主原料,以钾、钠、钙盐为辅料,均以粉状形态充分混合均匀,加水搅拌制成锂矿石混合料,经陈化、码墩堆料、煅烧、破碎、球磨、搅拌浸锂等,其煅烧时采用隧道窑的“半隔焰”的燃烧方式,即在隧道窑的每个运转窑车上建设燃烧室,用耐火材料板将砖块物料与燃气火焰隔开,同时在耐火材料板上预留有多条间隙,使加热气体能从燃烧室中通过间隙流出,直接给物料砖块传导热量。燃气喷枪火焰喷射至窑内燃烧室内,使之充分燃烧使窑炉内温度均匀、恒定。此工艺及装置,很好的避开了火焰直射的超高温度,有效防止“塌窑”现象的发生；提高了产品的市场竞争力。(The invention provides a method and a device for roasting and extracting lithium in a lithium ore tunnel kiln, which take lithium ore as a main raw material, potassium, sodium and calcium salts as auxiliary materials, fully and uniformly mix the lithium ore in a powdery form, add water and stir the mixture to prepare a lithium ore mixture, and perform aging, piling, calcining, crushing, ball milling, stirring and lithium leaching and the like. The flame of the gas spray gun is sprayed into the combustion chamber in the kiln, so that the gas spray gun can be fully combusted, and the temperature in the kiln is uniform and constant. The process and the device well avoid the ultrahigh temperature of direct flame irradiation, and effectively prevent the phenomenon of 'kiln collapse'; the market competitiveness of the product is improved.)

1. A lithium ore tunnel kiln roasting lithium extraction method is characterized by comprising the following steps of:

1) aging, namely aging the lithium ore mixture to obtain an aged lithium ore mixture,

2) piling the piers, conveying the aged lithium ore mixture to a storage bin of a press device through an automatic conveying device, pressing the mixture into a square brick shape through the press device, piling the square brick shape into corresponding pier piles meeting the requirements by an intelligent stacking device,

3) calcining, namely feeding the block pier stacking material obtained in the step 2) into a tunnel kiln device for calcining, wherein the calcining comprises drying in a drying area, calcining in a calcining area and cooling in a cooling area, the whole calcining time is controlled to be 6-10 hours, and the drying time is controlled to be more than 2 hours, so as to obtain a calcined material;

4) crushing, namely crushing the roasted material obtained in the previous step into granules of less than 150 mm by using a crushing device;

5) ball milling, namely ball milling the particles obtained in the step 4) to 100-200 meshes by adopting a wet ball milling method to obtain ball grinding materials;

6) stirring, washing and soaking lithium, filtering, separating and extracting lithium, precipitating lithium to prepare lithium salt, adding water into the ball-milled material obtained in the step 5), mixing, stirring, washing and soaking under the condition of uniform stirring, and completely dissolving soluble lithium subjected to roasting reaction in clinker in water solution; leaching water is evaporated water recycled by waste heat generated by a concentration evaporator, the temperature of the evaporated water is controlled to be 40-60 ℃, solid and liquid are separated into filtrate through filtration, and CO is added₂Gas or Na₂CO₃And chemically reacting with Li + to obtain lithium carbonate.

2. The lithium ore tunnel kiln roasting lithium extraction method as claimed in claim 1, wherein the aging treatment in step 1) is performed for 24-48 h while preventing evaporation of water on the surface layer of the aged lithium ore mixture during aging, so as to maintain uniform water content distribution of the aged lithium ore mixture, and to control the water content of the aged lithium ore mixture to 6-11 Wt%.

3. The method for roasting and extracting lithium by using the lithium ore tunnel kiln according to claim 1, wherein in the step 2), the pier stacking material is formed by stacking individual brick-shaped materials layer by layer to form a corresponding cube or cuboid-shaped pier, a plurality of even-numbered piers are combined to form the pier stacking material, a pier gap is controlled to be formed between any pier stacking material and the pier stacking material, and the distance between the pier gaps is controlled to be 50-100 mm; and simultaneously, the interval between the bricks forming any pier is controlled to be a brick gap, and the distance for controlling the size of the brick gap is controlled to be 10-30 mm.

4. The method for extracting lithium by roasting lithium ore in a tunnel kiln according to claim 1, wherein in the step 3), the step of roasting comprises the step of roasting the blocky mounds by using a device for preventing the blocky mounds from collapsing into the kiln during roasting in a roasting area of the tunnel kiln device after drying the blocky mounds, and the roasting temperature of the device for preventing the blocky mounds from collapsing into the kiln is controlled to be 750-980 ℃.

5. A device for realizing the method for extracting lithium by roasting in the lithium ore tunnel kiln of claim 1 comprises a tunnel kiln body 100 and a tunnel kiln car 12, wherein the tunnel kiln body 100 comprises a tunnel kiln inner cavity 19, a plurality of gas spray guns 4 and thermocouples 2 are correspondingly arranged on the wall surface of the tunnel kiln body 100, the tunnel kiln inner cavity 19 comprises a drying area 14, a roasting area 15 and a temperature reduction area 16, the tunnel kiln car 12 can movably operate in the drying area 14, the roasting area 15 and the temperature reduction area 16 in the tunnel kiln furnace cavity 19, and the device is characterized in that a plurality of devices for preventing the tunnel kiln car 12 from collapsing are arranged above the device for preventing the tunnel kiln car 11 from collapsing, and the device for preventing the tunnel kiln car from collapsing roasts the pier dump; the device for preventing the collapse of the calcining kiln comprises a supporting bottom plate 18, a refractory supporting column 8, a calcining flame isolating plate 7, a flame isolating combustion chamber 6 and a flame isolating gap 5; a plurality of fire-resistant supporting columns 8 are arranged between the supporting bottom plate 18 and the roasting flame-insulating plate 7, one ends of the fire-resistant supporting columns 8 are arranged on the supporting bottom plate 18, the other ends of the fire-resistant supporting columns 8 are propped against the roasting flame-insulating plate 7 on one side corresponding to the supporting bottom plate 18, the flame-insulating combustion chamber 6 is formed by a gap space between the supporting bottom plate 18 and the roasting flame-insulating plate 7, and the roasting flame-insulating plate 7 is provided with a flame-insulating gap 5.

6. The device as claimed in claim 5, wherein the gas outlet end of the gas spray gun 4 arranged on the inner wall surface of the inner cavity 19 of the tunnel kiln is corresponding to the inner cavity space of the muffle combustion chamber 6.

7. The apparatus of claim 5, wherein the flame-muffle gap 5 corresponds to the size of the pier gap 10.

8. The apparatus of claim 5, wherein the flame-proof holes 701 are respectively formed on the baking flame-proof plate 7 or the supporting bottom plate 18; the flame trap apertures 701 correspond in size to the brick gaps 9 on the pier piles 11.

9. The device as claimed in claim 5, wherein the tunnel kiln body 100 is provided with an air inlet duct 13 in the inner cavity thereof, and a plurality of air inlets 1301 are formed on the air inlet duct 13; the outlet of the air inlet 1301 corresponds to the upper position and the lower position of the roasting flame-isolating plate 7.

The technical field is as follows:

the invention relates to the field of lithium ore materials of a lithium battery new energy technology, mainly relates to roasting and device of lithium ore, and particularly relates to a method and device for roasting and extracting lithium in a lithium ore tunnel kiln.

Background art:

aiming at the current severe situation with stricter and stricter environmental requirements, new energy resources are vigorously developed in all countries; the method has important significance for the requirements of carbon peak reaching and carbon neutralization in the world and China, promoting the energy development of China to quickly transit from fossil energy to new energy, getting rid of the dependence on foreign energy, relieving the energy crisis and environmental protection problems in China and ensuring the energy safety. The lithium battery new energy technology and the application thereof are one of the main technical directions of new energy in the world and become a strategic industry which is vigorously supported by governments of various countries.

Lithium is known as energy metal and white petroleum, and a lithium compound is a basic core raw material of new energy of the lithium battery. Lithium is mainly present in natural ores in the form of spodumene, lepidolite, and xenotime as a lithic ore resource. Therefore, the extraction of lithium from lithium ore resources by adopting advanced process and device becomes the key point of technical research.

The most key link is the roasting of the lithium ore, and the lithium ore is roasted at high temperature to change the complex structure of the lithium ore into physical and chemical changes and change the chemical composition and physical properties, so that the lithium oxide which is difficult to dissolve is converted into the lithium compound which is easy to dissolve out. The lithium ore roasting process technology and the device determine the lithium extraction rate and are important indexes for evaluating the comprehensive utilization level of the lithium ore.

At present, the roasting of lithium ore mainly adopts a rotary kiln technology, the rotary kiln roasting technology is mature, the yield is high, the operation is easy, and the method is widely applied to industrial production. However, the whole kiln body and materials are always in a rotating and rolling working state in the roasting process of the rotary kiln, and the dynamic roasting mode has the disadvantages of large mechanical power, large energy consumption, difficult control of control precision and roasting temperature, and relatively large dust generated in the roasting process.

Therefore, the industry focuses on the research of the tunnel kiln roasting technology, and the tunnel kiln roasting is a static roasting mode relative to the rotary kiln, i.e., the tunnel kiln is stationary and the material is stationary, the material is pressed into a module brick shape, the module brick shape is stacked up by a mechanical arm layer, the module brick shape is stacked and placed on a kiln car, and the kiln car continuously runs through tunnel kilns in different temperature zones at a certain speed, so that the material roasting process is completed. The tunnel kiln roasting effectively avoids the defects of the rotary kiln, and has high lithium recovery rate and low energy consumption. Meanwhile, the equipment has high availability ratio, high utilization rate and low maintenance cost. And (3) roasting in a tunnel kiln, wherein the material enters a brick shape for roasting, and no dust is generated in the whole roasting process.

However, as the tunnel kiln roasting technology advances, various technical problems caused by the tunnel kiln roasting are still not enough, such as the problem which does not occur when other materials are roasted by the tunnel kiln, and the phenomenon of 'kiln collapse' which is generated or exists when the raw materials of the lithia ore or the lepidolite are roasted by the tunnel kiln, which becomes a key technical problem restricting the industrial application of the method and the device for roasting the lithia ore. The tunnel kiln generally uses gas fuel as a heat source, such as natural gas, coal gas and the like, and provides a roasting heat source for the tunnel kiln by injecting flame into the tunnel kiln from two side surfaces of the tunnel kiln through gas spray guns, and the temperature and the uniformity of the temperature in the tunnel kiln are adjusted by controlling the size of the flame of the spray guns, the distribution of the gas spray guns in the tunnel kiln and an air network system.

Since lithium ore forms a liquid phase and softens at a certain temperature, for example, during the calcination of lepidolite, the material gradually starts to generate a liquid phase when the temperature reaches 940 ℃, and the material softens when the temperature exceeds 1000 ℃. The lithium mineral material roasted in the tunnel kiln is pressed into a module, usually in a brick shape, which is beneficial to the operation of a robot, and the lithium mineral material is stacked at least on a flat kiln car. In the roasting process, local brick materials in a flame direct injection region are easy to form local high temperature due to concentrated combustion, while lithium ore block-shaped materials are easy to soften due to excessive high temperature, so that the phenomenon of 'kiln collapse' is caused, and collapse bricks caused by the 'kiln collapse' are easy to cause the occurrence of trucks and kiln blocking, so that production is forced to be stopped and the kiln is stopped; the brick can be placed into a kiln to be cleaned or repaired after being cooled, and the continuous normal production cannot be realized. The local high-temperature roasting of the material will produce over-sintered crystals, directly reducing the roasting quality.

Therefore, how to provide a method and a device for roasting and extracting lithium in a lithium ore tunnel kiln, when the lithium ore is roasted in the tunnel kiln, based on the problems of overburning and 'kiln collapse' of materials caused by overhigh local heating temperature of lithium mineral bricks in the tunnel kiln, the roasting device and the process technology of the lithium ore tunnel kiln are innovated so as to prevent the flame of a gas spray gun from being directly sprayed on the brick materials, reduce the local high temperature and enable the roasting temperature of the brick materials to be more uniform. Thoroughly solve the problem that the local high temperature causes the overburning or the kiln collapse when the lithium ore is roasted in the tunnel kiln. Greatly reduces the production cost of calcining and extracting lithium in the lithium ore tunnel kiln.

The invention content is as follows:

the invention aims to provide a method and a device for roasting and extracting lithium in a lithium ore tunnel kiln, which take lithium ore as a main raw material, potassium, sodium and calcium salt as auxiliary materials, fully and uniformly mix the lithium ore in a powdery form, add water and stir the mixture to prepare a lithium ore mixture, age the mixture, stack the mixture, calcine, crush, ball mill, stir and soak lithium and the like. The flame of the gas spray gun is sprayed into the combustion chamber in the kiln, so that the gas spray gun can be fully combusted, and the temperature in the kiln is uniform and constant. The process and the device well avoid the ultrahigh temperature of direct flame irradiation, and effectively prevent the phenomenon of 'kiln collapse';

the market competitiveness of the product is improved.

The invention aims to provide a method for roasting and extracting lithium in a lithium ore tunnel kiln, which takes lithium ore as a main raw material and potassium, sodium and calcium salts as auxiliary materials, fully and uniformly mixes the materials in a powdery form, adds water and stirs the materials to prepare a lithium ore mixture, and comprises the following steps:

1) aging, namely aging the lithium ore mixture to obtain an aged lithium ore mixture,

2) piling the piers, conveying the aged lithium ore mixture to a storage bin of a press device through an automatic conveying device, pressing the mixture into a square brick shape through the press device, piling the square brick shape into corresponding pier piles meeting the requirements by an intelligent stacking device,

3) calcining, namely feeding the block pier stacking material obtained in the step 2) into a tunnel kiln device for calcining, wherein the calcining comprises drying in a drying area, calcining in a calcining area and cooling in a cooling area, the whole calcining time is controlled to be 6-10 hours, and the drying time is controlled to be more than 2 hours, so as to obtain a calcined material;

4) crushing, namely crushing the roasted material obtained in the previous step into granules of less than 150 mm by using a crushing device;

5) ball milling, namely ball milling the particles obtained in the step 4) to 100-200 meshes by adopting a wet ball milling method to obtain ball grinding materials;

6) stirring, washing and soaking lithium, filtering, separating and extracting lithium, precipitating lithium to prepare lithium salt, adding water into the ball-milled material obtained in the step 5), mixing, stirring, washing and soaking under the condition of uniform stirring, and completely dissolving soluble lithium subjected to roasting reaction in clinker in water solution; leaching water is evaporated water recycled by waste heat generated by a concentration evaporator, the temperature of the evaporated water is controlled to be 40-60 ℃, solid and liquid are separated into filtrate through filtration, and CO is added₂Gas or Na₂CO₃And chemically reacting with Li + to obtain lithium carbonate.

The lithium ore tunnel kiln roasting lithium extraction method comprises the following steps of 1) ageing treatment, wherein the ageing treatment is controlled for 24-48 hours, the evaporation of water on the surface layer of an aged lithium ore mixture in the ageing process is prevented, the uniform distribution of the water content of the aged lithium ore mixture is kept, and the water content of the aged lithium ore mixture after the ageing treatment is controlled to be 6-11 Wt%.

According to the lithium ore tunnel kiln roasting lithium extraction method, in the step 2), the pier stacking is that independent brick-shaped materials are stacked layer by layer to form a corresponding cube or cuboid-shaped pier, a plurality of even piers are combined to form the pier stacking, a pier gap is controlled to be formed between any pier stacking and the pier stacking, and the distance of the pier gap is controlled to be 50-100 mm; and simultaneously, the interval between the bricks forming any pier is controlled to be a brick gap, and the distance for controlling the size of the brick gap is controlled to be 10-30 mm.

The lithium ore tunnel kiln roasting lithium extraction method comprises the step 3) of calcining, wherein after drying treatment, the pier stacking materials enter a roasting area in a tunnel kiln device for roasting, the blocky pier stacking materials are roasted through a calcination collapse prevention device, and the roasting temperature of the calcination collapse prevention device is controlled to be 750-980 ℃.

The invention also aims to provide a device for realizing the lithium extraction method by roasting the lithium ore tunnel kiln, which comprises a tunnel kiln body and a tunnel kiln car, wherein the tunnel kiln body comprises a tunnel kiln inner cavity, a plurality of gas spray guns and thermocouples are correspondingly arranged on the wall surface of the tunnel kiln body, the tunnel kiln inner cavity comprises a drying area, a roasting area and a cooling area, and the tunnel kiln car can movably run in the drying area, the roasting area and the cooling area in the tunnel kiln cavity; the device for preventing the kiln collapse during the calcination comprises a supporting bottom plate, a fireproof supporting column, a calcination flame isolating plate, a flame isolating combustion chamber and a flame isolating gap; a plurality of fire-resistant supporting columns are arranged between the supporting bottom plate and the roasting flame-isolating plate, one ends of the fire-resistant supporting columns are arranged on the supporting bottom plate, the other ends of the fire-resistant supporting columns are propped against the roasting flame-isolating plate on one side corresponding to the supporting bottom plate, the flame-isolating combustion chamber is formed by supporting the fire-resistant supporting columns in a gap space between the supporting bottom plate and the roasting flame-isolating plate, and flame-isolating gaps are arranged on the roasting flame-isolating plate.

The gas outlet end of the gas spray gun arranged on the inner wall surface of the inner cavity of the tunnel kiln corresponds to the inner cavity space of the flame-proof combustion chamber.

Further, the flame-proof gap corresponds to the size of the pier gap.

Preferably, flame isolating holes are respectively arranged on the roasting flame isolating plate or the supporting bottom plate; the flame isolating small holes correspond to the gaps of the bricks on the pier stacking materials.

Further, an air inlet pipeline is arranged in the inner cavity of the tunnel kiln body, and a plurality of air inlets are formed in the air inlet pipeline; the outlet of the air inlet corresponds to the upper position and the lower position of the roasting flame-isolating plate.

Compared with the rotary kiln roasting and the tunnel kiln roasting process in the prior art, the method and the device for extracting lithium by roasting the lithium ore in the tunnel kiln have the following outstanding advantages:

1) temperature control is more uniform: in the same temperature zone, the temperature difference is less than or equal to +/-8 ℃;

2) energy conservation and environmental protection: the power consumption is saved by more than or equal to 40 percent, and the fuel consumption is saved by more than or equal to 50 percent; the whole process of static baking of brick-shaped materials basically has no dust;

3) the equipment availability is high: the equipment availability is improved by more than 80%, the maintenance downtime is reduced, and the continuous production efficiency is improved.

4) The roasting quality of the lithium ore is high: because the roasting temperature control precision is high, the roasting quality is high, and the lithium leaching yield is high; the lithium leaching yield of the lepidolite roasting clinker can reach 95 percent;

secondly, compared with the roasting process of the conventional tunnel kiln for the lithium ore

1) Temperature control is easier and more uniform: the device is arranged in a calcination collapse prevention kiln device or a semi-muffle combustion chamber, so that direct injection of gas flame to lithium ore brick materials is avoided, temperature control is more uniform under the combined action of a gap stacking mode of the brick materials and negative pressure of an air grid system of a tunnel kiln, the temperature difference of a roasting area of the tunnel kiln can be controlled to be 1-3 ℃, and the phenomenon of local heating and over-burning of the materials caused by flame direct injection is avoided;

2) the tunnel kiln has higher availability: because of no 'collapse' and the phenomena of trucks and blocking, the completeness rate of the tunnel kiln can be improved by more than 10 percent, the tunnel kiln can be continuously produced for more than 6 months without overhaul, and the service time of the tunnel kiln is prolonged by more than one time compared with the prior tunnel kiln;

3) the lithium leaching yield is higher: in the roasting process, the phenomena of material over-sintered crystals and 'kiln collapse' caused by over-high local temperature are avoided, and the roasting of the lithia ore brick material, namely the pier stacking material is more uniform, so that the roasting quality is good, and the lithium leaching yield of the lepidolite roasting clinker is improved by 1-2%;

4) the energy consumption is lower: on the basis of heat insulation and preservation of a multi-layer concave-convex sealing structure between the kiln car and two side walls of the tunnel kiln, relative negative pressure is formed in the tunnel kiln body above a kiln car combustion chamber by utilizing the blowing, air suction and other effects of a main air net and a branch air net on the top of the tunnel kiln, so that a heat source is ensured to be upwards transferred to roasted materials, and the heat source is prevented from being lost to the lower part of the kiln car. The energy consumption can be further reduced by 5-10%.

On the other hand, the invention is based on the problems of material overburning and 'kiln collapse' caused by overhigh heating temperature of the lithium mineral brick blocks in the tunnel kiln, and innovations are made on the roasting device and the roasting process technology of the lithium mineral brick tunnel kiln so as to prevent the flame of a gas spray gun from being directly sprayed on brick material, reduce local high temperature and enable the roasting temperature of the brick material to be more uniform. The method adopts a 'semi-flame-proof' combustion mode, namely, one or a plurality of anti-burning collapse kiln devices or combustion chambers are arranged on each operating kiln car of the tunnel kiln, brick materials are separated from gas flame by refractory plates, and a plurality of gaps are reserved on the refractory plates, so that heating gas can flow out of the combustion chambers through the gaps, and heat is directly conducted to the material bricks. The flame of the gas spray gun is sprayed into the combustion chamber in the kiln to be fully combusted, firstly, the flame isolation plate is heated, and heat is transferred to the material bricks through the flame isolation plate; secondly, the high-temperature flame heats the gas in the combustion chamber in the kiln, and the hot gas flows out from the gap of the flame isolation plate through the air duct system to transfer heat, so that the temperature in the kiln is uniform and constant. The process and the device well avoid the ultrahigh temperature of direct flame irradiation, control the highest temperature at 980 ℃, heat the brick material more uniformly, and thoroughly solve the problem of over-burning or kiln collapse caused by over-high local temperature.

On each operating kiln car of the tunnel kiln, a space of a calcining collapse prevention kiln device or a shed is built by adopting a plurality of support columns and a plurality of small flat plate towers which are made of refractory materials. The preparation material of the calcination-collapse-preventing kiln device is made of refractory materials, for example, gaps are reserved among small flat plates of the calcination-collapse-preventing kiln device, the flat plates of the supporting bottom plate 18 are used for stacking at least material bricks, and the gaps among all layers of pier material bricks correspond to the gaps of a roof, so that the flow of hot gas is facilitated.

Preferably, the height of the refractory material support column, i.e. the refractory support column 8, is controlled to be 200-500 mm, i.e. the height of the flameholding combustion chamber 6, the size of the general controllable shelf board, i.e. the roasting flameholding board 7, is 600 × 600 mm square, when the roasting flameholding board 7 is built in the tower, a gap of 50-100 mm, i.e. a flameholding gap 5, is left between the board and the board, and the flameholding gap 5 may be a "semi-flameholding board" structure in which a plurality of roasting flameholding boards 5 are spliced to form an incomplete flameholding; or according to the designed running conditions of the inner cavity of the tunnel kiln and the tunnel kiln car, a plurality of flame isolating gaps 5 and flame isolating small holes 701 are divided by the complete roasting flame isolating plate 7, and in order to enhance the roasting effect, the roasting flame isolating plate 5 is also provided with the flame isolating small holes 701;

concave-convex grooves are arranged between the refractory material supporting columns or called refractory supporting columns 8 and the shed plate, namely the baking flame-isolating plate 7, and the refractory material supporting columns or called refractory supporting columns are mixed and bonded with high-temperature refractory mortar during installation. The gas spray guns 4 are arranged on two side surfaces of the tunnel kiln and are always aligned in the flame isolating combustion chambers 6, gas flames of the spray guns are directly sprayed into the combustion chambers, and each kiln car forms a combustion chamber. The flame isolation plate isolates the material from the gas flame, thereby preventing the flame of the spray gun from being directly sprayed on the brick material.

On the basis of heat insulation and heat preservation of a sealing structure between two side walls of a kiln car and two side walls of a tunnel kiln, a semi-flame-insulation combustion mode is adopted, gas flame is fully combusted in a combustion chamber, and relative negative pressure is formed in a tunnel kiln body above the kiln car combustion chamber by utilizing the blowing and suction effects of a main air net and a branch air net at the top of the tunnel kiln, so that a heat source is ensured to be upwards transferred to roasted materials, and the heat source is prevented from being lost to an invalid area below the plane of the kiln car. Firstly, heat is transferred into the kiln through a flame isolation plate; secondly, the hot gas in the combustion chamber is sprayed out from the gap of the flame isolating plate to transfer heat, so that the baking temperature of the brick material in the kiln is uniform and constant. The process and the device well change the roasting mode, namely, the original direct flame roasting is changed into the buffer indirect roasting, the situation ultrahigh temperature phenomenon generated by the direct flame materials is avoided, the roasting temperature of the tunnel kiln is softer, and the precise control is easy.

The temperature and the uniformity of the temperature in the tunnel kiln are adjusted by controlling the flame size of the spray gun, the gas spray gun in the kiln and the air network system. The roasting of the lithium ore is controlled at 750-980 ℃, the temperature difference of a roasting area is controlled at less than or equal to +/-8 ℃, and the lithium ore is roasted for 1-3 h at constant temperature under the condition of the temperature. At this time, the flame temperature of the gas spray gun should reach 1200-.

The brick materials stacked layer upon layer are divided into a plurality of layers of piers, a fixed gap is formed between every two layers of piers, and a fixed gap is also formed between every two adjacent layers of bricks. Gaps between the layer piers and between the brick blocks become air ducts for hot gas flow conduction, and the hot gas flow conduction passages correspond to gaps of the flame isolation plates of the combustion chamber of the kiln car, so that heat can be quickly conducted and diffused in the kiln body, and the temperature of the kiln body is more uniform. The distance between the gaps between the layer piers, namely the pier gap 10, is 50-100 mm, and the gap between the bricks, namely the brick gap 9, is 10-30 mm. The high-temperature flame heats the gas in the combustion chamber in the kiln, and the hot gas flows out from the gap of the flame isolating plate through the air duct system to transfer heat, so that the temperature in the kiln is uniform and constant. The process and the device well avoid the ultrahigh temperature of direct flame irradiation, control the highest temperature at 980 ℃, and heat the brick material more uniformly.

Description of the drawings:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention,

fig. 2 is an enlarged schematic view of a point a in fig. 1,

fig. 3 is an enlarged schematic view of B in fig. 1,

FIG. 4 is a left side view of an embodiment of the present invention,

figure 5 is a schematic view of the air inlet duct 13,

fig. 6 is a schematic structural view of another embodiment of the present invention,

FIG. 7 is a left side view of another embodiment of the present invention;

in the figure: 1. the device comprises a suction fan, 100, a tunnel kiln body, 2, a thermocouple, 3, a suction pipe, 4, a gas spray gun, 5, a flame-proof gap, 6, a flame-proof combustion chamber, 7, a roasting flame-proof plate, 701, flame-proof small holes, 8, a fireproof support column, 9, a brick gap, 10, a pier gap, 11, a pier stacking material, 12, a tunnel kiln car, 13, an air inlet pipeline, 1301, an air inlet, 14, a drying area, 15, a roasting area, 16, a cooling area, 17, a calcination collapse prevention device I, 1701, a calcination collapse prevention device II, 18, a support base plate, 19 and a tunnel kiln inner cavity.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to a specific corresponding embodiment and the accompanying drawings, wherein the upper, lower, left, right, etc. are referred to the accompanying drawings of the present invention; mass ratio or mass parts.

As shown in figures 1-2, the invention relates to a method and a device for roasting and extracting lithium in a lithium ore tunnel kiln, which takes lithium ore as a main raw material and potassium, sodium and calcium salts as auxiliary materials, the lithium ore and the calcium salts are fully and uniformly mixed in a powdery form, and water is added for stirring to prepare a lithium ore mixture, and the method comprises the following steps:

1) and (3) aging, namely aging the lithium ore mixture for 24-48 h, preventing the water on the surface layer of the aged lithium ore mixture from evaporating in the aging process, keeping the water content of the aged lithium ore mixture uniformly distributed, and controlling the water content of the aged lithium ore mixture to be 6-11 Wt%. In order to age the lithium ore mixture,

2) stacking the piers and stacking, conveying the aged lithium ore mixture to a storage bin of a press device through an automatic conveying device, pressing the mixture into a square brick shape through the press device, stacking the square brick shape into a pier stacking material meeting the corresponding requirements through an intelligent stacking device, wherein the pier stacking material refers to that each independent brick material is stacked layer by layer to form a corresponding cube or cuboid shape as a pier, combining a plurality of even piers into the pier stacking material, controlling a pier gap 10 to be arranged between any pier stacking material and a pier stacking material 11, and controlling the distance of the pier gap 10 to be 50-100 mm; simultaneously controlling the brick gap 9 among the bricks forming any pier, wherein the distance of the brick gap 9 is controlled to be 10-30 mm;

3) calcining, namely feeding the mound of the block pier in the step 2) into a tunnel kiln device for calcining, wherein the calcining comprises drying in a drying region, calcining in a calcining region and cooling in a cooling region, after drying the mound of the block pier, controlling the whole calcining time to be 6-10 hours and controlling the drying time to be more than 2 hours, when the mound of the block pier enters the calcining region in the tunnel kiln device for calcining, calcining the mound of the block pier by adopting a calcination collapse prevention kiln device, and controlling the temperature of the calcination collapse prevention kiln device in the calcining to be 750-980 ℃ to obtain the calcined material, wherein the calcination collapse prevention kiln device comprises a calcination collapse prevention kiln I17 and a calcination collapse prevention kiln II 1701;

4) crushing, namely crushing the roasted material obtained in the previous step into granules of less than 150 mm by using a crushing device;

5) ball milling, namely ball milling the particles obtained in the step 4) to 100-200 meshes by adopting a wet ball milling method to obtain ball grinding materials;

6) stirring, washing and soaking lithium, filtering, separating and extracting lithium, precipitating lithium to prepare lithium salt, adding water into the ball-milled material obtained in the step 5), mixing, stirring, washing and soaking under the condition of uniform stirring, and completely dissolving soluble lithium subjected to roasting reaction in clinker in water solution; leaching water is evaporated water recycled by waste heat generated by a concentration evaporator, the temperature of the evaporated water is controlled to be 40-60 ℃, solid and liquid are separated into filtrate through filtration, and CO is added₂Gas or Na₂CO₃And chemically reacting with Li + to obtain lithium carbonate.

The device for realizing the lithium extraction method by roasting the lithium ore in the tunnel kiln comprises a tunnel kiln body 100 and a tunnel kiln car 12, wherein the tunnel kiln body 100 comprises a tunnel kiln inner cavity 19, a plurality of gas spray guns 4 and thermocouples 2 are correspondingly arranged on the wall surface of the tunnel kiln body 100, the thermocouples 2 are uniformly distributed on the corresponding wall surface of the tunnel kiln body 100, so that the temperature in the tunnel kiln inner cavity 19 can be accurately detected, the tunnel kiln inner cavity 19 comprises a drying area 14, a roasting area 15 and a temperature reduction area 16, the tunnel kiln car 12 can movably run in the drying area 14, the roasting area 15 and the temperature reduction area 16 in the tunnel kiln inner cavity 19, a plurality of anti-collapse devices are arranged above the tunnel kiln car 12, the pier material 11 is arranged above the anti-collapse devices, and the pier material is roasted by the anti-collapse devices; thus, bricks pressed by the lithium ore mixture of the pier stacking material 11 can be fully combusted; and the air outlet end of the gas spray gun 4 arranged on the inner wall surface of the inner cavity 19 of the tunnel kiln is controlled to correspond to the inner cavity space of the flame-proof combustion chamber 6. An air inlet pipeline 13 is arranged in the inner cavity of the tunnel kiln body 100, and a plurality of air inlets 1301 are arranged on the air inlet pipeline 13; the outlet of the air inlet 1301 corresponds to the upper position and the lower position of the roasting flame-isolating plate 7.

Example 1

As shown in fig. 1-2 and 4, the method for extracting lithium salt by roasting lithium ore in tunnel kiln of the invention takes lithium ore as main raw material and potassium, sodium, calcium salt and the like as auxiliary materials, which are fully and uniformly mixed in powder form; controlling the ratio of the main raw material to the auxiliary materials to be 55-70%: 30-45% (dry basis), total 100%; the lithium ore is mainly in the form of spodumene, lepidolite, lithium porcelain stone, phospholith and other lithium ore resources and is a lithium ore mixture;

1) aging, namely aging the lithium ore mixture for 24-28 h; various raw materials and auxiliary materials in the lithium ore mixture are further combined through aging, so that the water distribution of the lithium ore mixture is uniform, and the forming performance of the lithium ore mixture can be improved; the aging time is controlled not to be too long so as to prevent the water on the surface layer of the mixture from evaporating and cause uneven water distribution again, the water mass ratio of the lithium ore mixture is controlled to be 6-11%, and the water distribution needs to be uniform; aging the lithium ore mixture;

2) stacking piers, namely delivering the aged lithium ore mixture, namely the aged lithium ore mixture to an automatic bin above a press through an automatic conveying system, making the lithium ore mixture into a brick shape through a press with the pressure of 1200-3000 tons, stacking the brick material onto the plane of a shed plate built in a kiln car tower through a grouping machine and an intelligent manipulator, stacking the brick material layer by layer to form a corresponding cube or cuboid shape as a pier, dividing the stacked brick material layer by layer into 2-6 piers which are symmetrical and even as shown in figures 1 and 2, and controlling the distance between the piers, namely the pier gap 10, to be 50-100 mm; meanwhile, the gap between the bricks of each pier and the brick arrangement, namely the brick gap 9, is controlled to be 10-30 mm, so that smooth flowing and uniform distribution of a heat source are facilitated;

3) calcining, namely, as shown in figure 1, fully automatically and continuously feeding the kiln car loaded with the brick materials into a tunnel kiln body 100, sequentially passing through a drying area 14, a roasting area 15 and a cooling area 16 in an inner cavity 19 of the tunnel kiln, and as shown in figure 4, controlling the time for completing the whole process of roasting of the tunnel kiln to be 6-9 h; the device for preventing the kiln collapse caused by calcination is a kiln collapse preventing device I17 which comprises a supporting bottom plate 18, a refractory supporting column 8, a calcination flame isolating plate 7, a flame isolating combustion chamber 6 and a flame isolating gap 5; a plurality of refractory supporting columns 8 are arranged between the supporting bottom plate 18 and the roasting flame-insulating plate 7, one ends of the refractory supporting columns 8 are arranged on the supporting bottom plate 18, the other ends of the refractory supporting columns 8 are propped against the roasting flame-insulating plate 7 on one side corresponding to the supporting bottom plate 18, the flame-insulating combustion chamber 6 is formed by a gap space between the supporting bottom plate 18 and the roasting flame-insulating plate 7, which is supported by the refractory supporting columns 8, and a plurality of flame-insulating gaps 5 are arranged on the roasting flame-insulating plate 7; the flame-proof gap 5 corresponds to the pier gap 10, and the distance is generally controlled to be 50-100 mm. In order to make the temperature of the roasting atmosphere more balanced, namely, the lithium ore mixture in the inner cavity of the tunnel kiln is heated more uniformly, so as not to form concentrated overheating roasting on the pier stacking material 11, preferably, the roasting flame isolating plate 7 or the supporting bottom plate 18 is respectively provided with a flame isolating small hole 701; the flame-proof apertures 701 correspond to the brick gaps 9 in the pier stacking 11, and the size distance is generally controlled to be 10-30 mm.

The tunnel kiln car 12 or the kiln car has the same meaning, the brick materials are dried through a drying area of a tunnel kiln inner cavity 19 in a tunnel kiln body 100, the temperature in the drying area 14 is controlled to be 100-plus-150 ℃, and a heat source of the brick materials is transferred from a high-temperature roasting area 15 to a low-temperature drying area 14 and utilizes waste heat; and controlling the drying time to be 2-6 h, wherein the drying time of the brick material cannot be too fast, and the moisture of the brick material is slowly discharged and evaporated as much as possible. If the drying time is too short and the moisture content of the brick material is still high, when the brick material enters a high-temperature roasting area, obvious cracks are easily generated on the surface of the brick material, and the brick is broken seriously to cause the collapse of the piled brick piers, namely 'kiln collapse';

the tunnel kiln car 12 roasts the brick material at high temperature through a roasting area 15, which is the key for determining the quality of roasting and lithium extraction; the roasting temperature of the roasting area 15 is accurately controlled to be 750-980 ℃, the heat source of the roasting area is that gas flame is sprayed to a flame isolating combustion chamber 6 or a semi-flame isolating combustion chamber of a kiln collapse prevention device 17 below a brick material platform of a kiln car by using gas spray guns 4 distributed from two side surfaces of a tunnel kiln, the embodiment is provided with the kiln collapse prevention device 17, and the kiln collapse prevention device 17 comprises a supporting bottom plate 18, a fireproof supporting column 8, a roasting flame isolating plate 7, a flame isolating combustion chamber 6 and a flame isolating gap 5; one end of the fire-resistant supporting column 8 is connected to a supporting bottom plate 18, the other end of the fire-resistant supporting column is supported against the roasting muffle plate 7, the supporting bottom plate 18 of the embodiment adopts a heat-insulating flat plate of the tunnel kiln car 12, or is an upper platform plate of the tunnel kiln car 12, the fire-resistant supporting column 8 is designed to be provided with a plurality of pieces according to the requirement, not only the roasting muffle plate 7 is ensured not to collapse, but also the space of the muffle combustion chamber 6 is ensured, the roasting muffle plate 7 can be a whole or an integer, or a plate corresponding to each pier material 11, and a gap size of the muffle gap 5 is arranged between the plates of each pier material 11 and corresponds to the pier gap 10; when the roasting flame-proof plate 7 is designed into a whole, the flame-proof gap 5 is also required to be designed on the roasting flame-proof plate; the roasting muffle plate 7 is also provided with a flame isolating small hole 701, the size and the position of the flame isolating small hole 701 correspond to the brick gap 9 of the pier stacking material 11, so that heat generated by the combustion of the flame isolating combustion chamber 6 is correspondingly transferred to the pier gap 1 and the brick gap 9 of the pier stacking material 11 through the flame isolating gap 5 and the flame isolating small hole 701, and accordingly the pier stacking material 11 is roasted in a balanced manner, the collapse of the lithium ore tunnel kiln during the roasting is effectively prevented through use and practice, the roasting time of the kiln is greatly increased, the maintenance and shutdown time is reduced, the continuous production efficiency is improved, and the equipment integrity rate is improved by more than 80%;

meanwhile, a main fan 1 and a plurality of sub-fans which are arranged at the top of a roasting area of the tunnel kiln are used for forming a blower 3 of an air duct air net and an air inducing function, so that relative negative pressure is formed above a semi-muffle flat plate in the tunnel kiln, a heat source is enabled to transfer from a combustion chamber to a space for stacking and carrying brick materials above the kiln body, namely heat is transferred through a muffle gap 5 between roasting muffle plates 7 of a muffle combustion chamber 6, the size of the muffle gap 5 corresponds to that of a pier gap 10, as shown in figures 1 and 2, as shown in figure 1, an air inlet pipeline 13 is arranged on the inner side wall surface of a tunnel kiln inner cavity 19 of a tunnel kiln body 100 of the tunnel kiln, and a plurality of air inlets 1301 are arranged on the air inlet pipeline 13; the outlet of the air inlet 1301 corresponds to the upper position and the lower position of the roasting flame-isolating plate 7. In the embodiment, the position of the air inlet 13 of the air inlet pipeline 13 of the air supply device is controlled, so that the combustion heat from the flame-proof combustion chamber 6 is more uniformly transferred to the pier stockpile 11 along with the air; the heat flow air channel is unblocked through the reserved gaps between the piers and between the bricks of the brick material, so that the temperature of the whole roasting area is uniform, and the temperature difference of each point of the longitudinal section is small; the brick material needs to be baked for 1-3 h at constant temperature to be completely and thoroughly baked;

the roasting area of the invention adopts the structural design and the process of the combustion chamber, so that the phenomenon that the material is directly sprayed by gas flame, which is easy to cause the local over-temperature softening of the material to cause 'kiln collapse' is effectively avoided; secondly, on the basis of heat insulation and heat preservation of a multi-layer concave-convex sealing structure and the like between two side walls of a kiln car and a tunnel kiln, design and process of an air net system with air blowing and air inducing functions are adopted, relative negative pressure is formed in a space for stacking brick materials on a semi-muffle plate of a semi-muffle combustion chamber of the kiln car, a heat source of a combustion chamber is effectively transferred to the upward brick materials of the kiln car, heat required by roasting the brick materials is ensured, and the possibility that the heat source of the combustion chamber is dissipated to the lower part of the kiln car is prevented; thirdly, stacking the partition plate gap of the combustion chamber with a semi-muffle and the gap of brick materials to effectively control smooth transfer of a heat source and constant temperature in the kiln;

the kiln car moves the baked brick material to a cooling area; cooling the clinker of the brick piles 11 on the tunnel kiln car 12 to below 80 ℃ in the cooling area 16 in an air cooling mode, and controlling the cooling time in the cooling area 16 to be 1-1.5 h; at the moment, the kiln car carries the brick clinker to be transported out of the tunnel kiln.

4) And crushing, namely after the brick clinker carried by the kiln car is conveyed out of the tunnel kiln, conveying the brick clinker on the kiln car into a crusher through a full-automatic brick holding machine to carry out crushing on the brick clinker, and crushing the brick clinker into particles of less than 150 mm.

5) And (3) wet ball milling: and (3) feeding the crushed clinker particles into a ball mill through a conveyer belt for wet ball milling to 100-200 meshes. The ball milling of the materials can not be over-milled, the materials are milled too finely, and the materials are easy to stick filter cloth during the filtration of solid-liquid separation, thereby affecting the filtration effect and reducing the filtration efficiency.

6) Stirring and washing to soak lithium: mixing the ball-milled lithium ore clinker slurry and an aqueous solution according to a solid-liquid weight ratio of 1: 0.5 to 1.0 percent of the raw materials are mixed and stirred at a constant speed in a leaching pool for carrying out agitation washing leaching treatment, and the soluble lithium in the clinker after the roasting reaction is completely dissolved in water solution. The leaching water is mainly recycled by using evaporated water generated by a concentration evaporator, and the lithium leaching effect is better by using waste heat capable of reaching 40-60 ℃ to evaporate water. Solid-liquid filtration and separation are carried out to extract lithium. Carrying out solid-liquid separation on the lithium leaching mixed liquor by a belt filter, wherein the solid is leaching residue, namely lithium residue; the liquid is lithium salt solution, namely industrial brine. The lithium salt solution is mainly lithium sulfate or lithium chloride or lithium phosphate or lithium carbonate or lithium hydroxide and the like; precipitating lithium to prepare lithium salt, further removing impurities and purifying the lithium salt solution, and carbonizing to generate lithium carbonate, namely CO₂Gas or Na₂CO₃With Li⁺The chemical reaction is carried out, and lithium hydroxide is generated through causticization treatment, namely, the lithium hydroxide is obtained through the chemical reaction of NaOH and Li +.

On the basis of heat insulation and heat preservation of a tunnel kiln car 12 or a called kiln car and 2-3 layers of concave-convex sealing structures and the like built between two side walls of a tunnel kiln, a semi-flame-insulated combustion mode is adopted, gas flame is fully combusted in a combustion chamber, and relative negative pressure is formed in a tunnel kiln body above the combustion chamber of the tunnel kiln car by utilizing the blowing and suction effects of a main air net and a branch air net at the top of the tunnel kiln, so that a heat source is ensured to be upwards transferred to roasted materials, and the heat source is prevented from being dissipated to an invalid area below the plane of the tunnel kiln car. Firstly, heat is transferred into the kiln through a flame isolation plate; secondly, the hot gas in the combustion chamber is sprayed out from the gap of the flame isolating plate to transfer heat, so that the baking temperature of the brick material in the kiln is uniform and constant. The process and the device well change the roasting mode, namely, the original direct flame roasting is changed into the buffer indirect roasting, so that the situation of ultrahigh temperature generated by the direct flame material is avoided, the roasting temperature of the tunnel kiln is softer, and the precise control is easy; the temperature and the uniformity of the temperature in the tunnel kiln are adjusted by controlling the flame size of the spray gun, the gas spray gun in the kiln and the air network system. Roasting the lithium ore at 750-980 ℃, controlling the roasting temperature difference in the roasting area to be less than or equal to +/-8 ℃, and roasting at constant temperature for 1-3 h, wherein the flame temperature of a gas spray gun 4 is controlled to be 1200-1500 ℃; the temperature control in the roasting process of the invention adopts the thermocouple 2 arranged on the tunnel kiln body 100 for detection control.

The brick materials stacked layer upon layer are divided into a plurality of layers of piers, a fixed gap is formed between every two layers of piers, and a fixed gap is also formed between every two adjacent layers of bricks. Gaps between the layer piers and between the brick blocks become air ducts for hot gas flow conduction, and the hot gas flow conduction passages correspond to gaps of the flame isolation plates of the combustion chamber of the kiln car, so that heat can be quickly conducted and diffused in the kiln body, and the temperature of the kiln body is more uniform. The gap between the layer piers is 50-100 mm, and the gap between the brick and the brick is 10-30 mm.

Example 2

The contents are the same as those in example 1 and the above-described embodiment except for the following description;

as shown in fig. 3, 6 and 7, in order to improve the efficiency of calcination and maintain the balance of heat distribution during calcination, and more effectively prevent the collapse phenomenon, in this embodiment, as shown in fig. 6, the calcination collapse prevention device in this embodiment includes a calcination collapse prevention kiln I17 and a calcination collapse prevention kiln II 1701, one calcination collapse prevention kiln I17 is disposed on the upper platform surface or flat plate of the tunnel kiln car 12, i.e. the supporting bottom plate 18 of the calcination collapse prevention kiln I17 is the upper platform panel of the tunnel kiln car 12, the pier compost 11 is disposed above the corresponding calcination muffle plate 7, another calcination collapse prevention kiln II 1701 is disposed above the pier compost 11, i.e. the supporting bottom plate 18 of the calcination collapse prevention kiln II 1701 and the calcination muffle plate 7 have the same structure, i.e. the supporting bottom plate 18 and the calcination muffle plate 7 on the calcination collapse prevention kiln II 1701 are both provided with the muffle gaps 5 and the muffle holes 701, the supporting floor 18 of the calcination collapse preventing device II 1701 is placed on the pier dump 11 and the upper surface of the calcination flame barrier 7 is also provided with the pier dump 11, as shown in fig. 3, another calcination collapse preventing device 1701 is also provided at a corresponding position in the middle of the pier dump 11, and the supporting floor 18 of the calcination collapse preventing device 1701 is structured to correspond to the calcination flame barrier 7, that is, the supporting floor 18 is also provided with the flame barrier gap 5 and the flame barrier holes 701 and corresponds to the calcination collapse preventing device 17. The roasting flame-proof plate 7 and the supporting bottom plate 18 in this embodiment may be an integral plate, on which the flame-proof gap 5 and the flame-proof small hole 701 are correspondingly arranged, or may be formed by a plurality of independent roasting flame-proof plates, and the flame-proof gap 5 is formed by splicing the independent roasting flame-proof plates 7; by adopting the structural design, the lithium ore calcination of the invention saves the power consumption by more than or equal to 40 percent and the fuel consumption by more than or equal to 50 percent; the whole process of static baking of brick-shaped materials basically has no dust. The lithium leaching yield of the lepidolite roasting clinker can reach 95 percent.

The description is only an overview of the invention, and can be implemented according to the content of the description, which is only a preferred embodiment of the invention, and not to limit the invention in any way. Those skilled in the art can make numerous possible variations and modifications to the described embodiments, or modify equivalent embodiments, without departing from the scope of the invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technology of the present invention are within the protection scope of the present invention, unless the content of the technical solution of the present invention is departed from.