System for producing lime from carbide slag and production process thereof

Abstract

The invention belongs to the technical field of industrial waste residue recycling, and particularly discloses a system for producing lime from carbide slag and a production process thereof. The system is composed of a carbide slag warehouse, metering equipment, conveying equipment A, conveying equipment B, conveying equipment C, conveying equipment D, a homogenization metering system, a cyclone preheating system, a cyclone calcination decomposition system, a suspension cooling system, a lime warehouse, a homogenization metering system, granulation equipment, a calcium carbide production line and the like. The method has the beneficial effects that the technological process is simple, the layout is compact, the suspension preheating decomposition calcining technology of cyclone preheating, pipeline type decomposition furnace and suspension cooling is adopted, continuous production can be achieved, the production efficiency is high, the carbide slag decomposition rate is larger than 98%, and the rate of finished products is high; the calcium carbide slag suspension calcination technology is adopted, the unit product energy consumption of lime can be reduced, and therefore the unit energy consumption of the calcium carbide finished product is reduced, calcium carbide by-product furnace gas is adopted as calcination fuel, reasonable and full utilization of coal resources can be achieved, and no extra coal resource consumption exists.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial waste slag recycling, and specifically relates to a lime production system of carbide slag and a production process thereof. Background Art

[0002] Calcium carbide slag is an industrial waste slag with calcium hydroxide as the main component after acetylene is obtained by hydrolysis of calcium carbide. Calcium carbide is widely used in organic synthesis, oxyacetylene welding, steel desulfurization and other fields in industry, and is an important raw material for the production of PVC. Especially in recent years, with the growth of domestic PVC production, the demand for calcium carbide has further increased, thereby promoting the continuous growth of calcium carbide slag production. According to statistics, my country's calcium carbide production in 2023 is about 27.5 million tons. 1 ton of calcium carbide can produce 1.2 tons of dry-based calcium carbide slag, so my country's calcium carbide slag produced in 2023 is about 33 million tons.

[0003] At present, the production of cement as a raw material has become the main way to comprehensively utilize carbide slag. However, the process of carbide slag cement is complex, with high energy consumption, large investment, low output and poor market competitiveness. Carbide slag can also be directly used in construction projects to prepare lime mortar and used in the cement mortar of highway roadbeds, but it is limited by its high water content, high transportation cost and scattered use points, and it is easy to cause new environmental pollution. Carbide slag can also be used in environmental protection fields such as sewage treatment, soil improvement, flue gas desulfurization, but many technologies and methods are not yet mature and the amount is limited. Carbide slag can be used to make chemical products such as lime, high whiteness ultrafine calcium carbonate, and coatings, but because carbide slag contains certain impurities, the quality of the products produced is not high, the production cost is high, and the economic benefits are poor. A large amount of carbide slag cannot be utilized as a resource, so most companies choose to pile or landfill the carbide slag on site.

[0004] Calcium carbide waste residue is a Class II general industrial solid waste. Its strong alkaline leachate can pollute soil and water bodies, and long-term storage can lead to serious environmental pollution. The flammable and explosive gases in calcium carbide slag are prone to explosion when encountering fire or high temperature, causing personal injury and environmental damage. In addition, the heavy metals and organic substances in calcium carbide slag also pose certain hazards to the environment and human health.

[0005] Calcium carbide slag is an industrial waste that must be taken seriously and given priority in its treatment and utilization. Only by seeking breakthroughs in process technology can we turn calcium carbide slag into treasure and promote the green and sustainable development of the calcium carbide industry.

[0006] Therefore, based on the above problems, the present invention provides a system for producing lime from carbide slag and a production process thereof. Summary of the invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a system for producing lime from carbide slag and its production process, so as to solve the problems of limited consumption of carbide slag, long-term stacking, environmental pollution, etc., and to make efficient and comprehensive utilization of carbide slag.

[0008] Technical solution: The first aspect of the present invention provides a carbide slag lime production system, which consists of a carbide slag storage, metering equipment, conveying equipment A, conveying equipment B, conveying equipment C, conveying equipment D, a homogenizing metering system, a cyclone preheating system, a cyclone calcining and decomposition system, a suspension cooling system, a lime storage, a homogenizing metering system, a granulating equipment and a carbide production line;

[0009] The carbide slag powder in the carbide slag warehouse is measured by a metering device and then sent to the cyclone preheating system via a conveying device B;

[0010] The cyclone preheating system preheats and removes impurities from the carbide slag powder to remove impurities in the carbide slag.

[0011] The carbide slag powder that has been cleaned and preheated is sent to a cyclone calcination and decomposition system for calcination and decomposition;

[0012] The calcined and decomposed lime product is sent to a suspension cooling system for cooling and collection;

[0013] The finished lime products collected by the cyclone cooling system are sent to the lime storage for storage via the conveying device C;

[0014] The lime powder coming out from the bottom of the lime storage is measured by the homogenization metering system and then sent to the granulation equipment through the conveying equipment D;

[0015] The granulation equipment extrudes and granulates the lime;

[0016] The prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as a raw material for calcium carbide production.

[0017] In the technical solution, the carbide slag storage is connected to a metering device; the metering device is connected to one end of a conveying device B; the other end of the conveying device B is connected to a cyclone preheating system; wherein the metering device is a quantitative feeder; and the conveying device B is a belt conveyor and a bucket elevator.

[0018] In the technical solution, the cyclone preheating system in step 2 includes a drying and dispersing machine, a powder selecting and slag removing machine and a bag dust collector; the cyclone preheating system is connected to the bag dust collector, and the exhaust gas from the cyclone preheating system is purified by the bag dust collector and then discharged, and the particles collected by the bag dust collector are undecomposed calcium hydroxide, which are sent to the kiln ash bin and then sent to the furnace for calcination again through the conveying equipment A; wherein the calcium carbide slag powder conveyed by the conveying equipment B is first processed by the drying and dispersing machine and then enters the powder selecting and slag removing machine for further processing.

[0019] In the technical solution, the cyclone calcination decomposition system in step 3 includes a decomposition furnace and a cyclone, and the decomposition furnace is respectively connected to the powder selection and slag removal machine and the cyclone; the calcium carbide slag powder preheated by the drying and dispersing machine, the powder selection and slag removal machine and the bag dust collector is sent to the decomposition furnace for suspended calcination, and the finished lime product after calcination and decomposition enters the next-level cyclone for material-gas separation, and the high-temperature exhaust gas enters the upper cyclone preheating system to dry and preheat the calcium carbide slag powder.

[0020] In the technical solution, the suspension cooling system in step 4 includes a suspension cooler, a high-temperature induced draft fan, a hot air supplementary combustion furnace and an extraction and purification device. The suspension cooler adopts air cooling and directly uses fresh air for rapid cooling; one end of the suspension cooler is connected to the high-temperature induced draft fan, the other end of the suspension cooler is connected to the cyclone, one end of the high-temperature induced draft fan is connected to the hot air supplementary combustion furnace, and the extraction and purification equipment is respectively connected to the calcium carbide production line and the hot air supplementary combustion furnace; the hot air exiting the suspension cooler is heat-recovered and utilized, and is sent to the hot air supplementary combustion furnace through the high-temperature induced draft fan to provide the hot air required for combustion; the fuel of the hot air supplementary combustion furnace is carbon monoxide, a by-product of the production of calcium carbide by the calcium carbide production line, which is sent to the furnace for combustion through a pipeline through the carbon monoxide extraction and purification equipment.

[0021] In the technical solution, the conveying equipment C in step 5 includes but is not limited to an air conveying chute.

[0022] In the technical solution, the homogenizing and metering system is installed at the bottom of the lime storage.

[0023] In the present technical solution, the conveying equipment D is an air conveying chute and a bucket elevator.

[0024] Another aspect of the present invention provides a production process for a lime production system using carbide slag, the process comprising the following steps:

[0025] Step 1, measure the carbide slag powder in the carbide slag warehouse through the metering equipment and then send it to the cyclone preheating system through the conveying equipment B; Step 2, the cyclone preheating system preheats and removes impurities in the carbide slag; Step 3, the preheated carbide slag powder with impurities removed is sent to the cyclone calcination and decomposition system for calcination and decomposition; Step 4, the finished lime product after calcination and decomposition is sent to the suspension cooling system for cooling and collection; Step 5, the finished lime product collected by the cyclone cooling system is sent to the lime warehouse for storage through the conveying equipment C; Step 6, the lime powder coming out of the bottom of the lime warehouse is measured by the homogenization metering system and sent to the granulation equipment through the conveying equipment D; Step 7, the granulation equipment extrudes and granulates the lime; Step 8, the prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as the raw material for calcium carbide production in calcium carbide production.

[0026] In the technical solution, the water content of the carbide slag powder in step 1 is 6%-10%; the impurities removed from the carbide slag in step 2 include but are not limited to glass.

[0027] Compared with the prior art, the system for producing lime from carbide slag and the production process thereof of the present invention have the following beneficial effects:

[0028] 1. The process flow of the present invention is simple and the system layout is compact. It adopts the suspension preheating decomposition and calcination technology of cyclone preheating plus pipeline decomposition furnace plus suspension cooling, which can realize continuous production with high production efficiency. The decomposition rate of calcium carbide slag is greater than 98%, and the yield rate is high. The finished lime produced has good activity. This suspension calcination production technology is very advanced, efficient and environmentally friendly.

[0029] 2. The present invention adopts the technology of suspended calcination of calcium carbide slag, which can reduce the unit energy consumption of lime product, thereby reducing the unit energy consumption of calcium carbide finished product, and the calcination fuel adopts the furnace gas of calcium carbide by-product, which can realize the rational and full utilization of coal resources without additional coal resource consumption; the use of this technology will greatly reduce the energy cost of products, which is in line with the development direction of energy conservation and consumption reduction in the calcium carbide industry and brings greater economic benefits to enterprises.

[0030] 3. The calcined raw material of the present invention is industrial waste slag, which can basically realize the recycling of calcification and achieve the goal of zero discharge of solid waste, solve the problem of difficult treatment of industrial solid waste slag, reduce the environmental pollution caused by the stacking and burial of calcium carbide slag and the treatment cost of solid waste, and has extremely high social environmental benefits and corporate economic benefits.

[0031] 4. The present invention has greater environmental value than the large amount of carbon dioxide produced by calcining limestone. It is a real low-carbon production and fully complies with the country's low-carbon environmental protection strategic goals. It provides a way for enterprises to occupy a dominant position in the carbon trading market and establish a benchmark image.

[0032] 5. The present invention adopts a pure dry production process. There is no production water or production wastewater, only a small amount of domestic water and cooling water. The cooling water does not directly contact the raw fuel and products, and only serves as a medium for heat exchange. The water quality does not undergo chemical changes. Most of it can be recycled, and a small amount can be directly discharged. The domestic wastewater does not contain harmful substances and can be directly discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1The invention discloses a system for producing lime from carbide slag and a flow chart of its production process. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "one side", "the other side", "front", "back", "middle part", "inside", "top end", "bottom end", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0038] Example

[0039] like Figure 1 A carbide slag lime production system shown in the figure, the system consists of a carbide slag silo, metering equipment, conveying equipment A, conveying equipment B, conveying equipment C, conveying equipment D, a homogenizing metering system, a cyclone preheating system, a cyclone calcining and decomposition system, a suspension cooling system, a lime silo, a homogenizing metering system, a granulating equipment and a carbide production line;

[0040] The carbide slag powder in the carbide slag warehouse is measured by a metering device and then sent to the cyclone preheating system via a conveying device B;

[0041] The cyclone preheating system preheats and removes impurities from the carbide slag powder to remove impurities in the carbide slag.

[0042] The carbide slag powder that has been cleaned and preheated is sent to a cyclone calcination and decomposition system for calcination and decomposition;

[0043] The calcined and decomposed lime product is sent to a suspension cooling system for cooling and collection;

[0044] The finished lime products collected by the cyclone cooling system are sent to the lime storage for storage via the conveying device C;

[0045] The lime powder coming out from the bottom of the lime storage is measured by the homogenization metering system and then sent to the granulation equipment through the conveying equipment D;

[0046] The granulation equipment extrudes and granulates the lime;

[0047] The prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as a raw material for calcium carbide production.

[0048] In addition, preferably, the carbide slag warehouse is connected to a metering device; the metering device is connected to one end of the conveying device B; the other end of the conveying device B is connected to the cyclone preheating system;

[0049] Among them, the metering equipment is a quantitative feeder; the conveying equipment B is a belt conveyor and a bucket elevator.

[0050] In addition, preferably, the cyclone preheating system in step 2 includes a drying and dispersing machine, a powder selection and slag removal machine and a bag dust collector; the cyclone preheating system is connected to the bag dust collector, and the exhaust gas from the cyclone preheating system is purified by the bag dust collector and then discharged, and the particles collected by the bag dust collector are undecomposed calcium hydroxide, which are sent to the kiln ash bin and sent to the furnace for calcination again through the conveying equipment A;

[0051] Among them, the calcium carbide slag powder transported by the conveying equipment B is first processed by the drying and disintegrating machine and then enters the powder selection and slag removal machine for further processing.

[0052] In addition, preferably, the cyclone calcination decomposition system in step 3 includes a decomposition furnace and a cyclone, and the decomposition furnace is respectively connected to the powder selection and slag removal machine and the cyclone; the calcium carbide slag powder that has been preheated by the drying and disintegrating machine, the powder selection and slag removal machine and the bag dust collector is sent to the decomposition furnace for suspended calcination, and the finished lime product after calcination and decomposition enters the next-level cyclone for material and gas separation, and the high-temperature exhaust gas enters the upper cyclone preheating system to dry and preheat the calcium carbide slag powder.

[0053] In addition, preferably, the suspension cooling system in step 4 includes a suspension cooler, a high-temperature induced draft fan, a hot air supplementary combustion furnace and an extraction and purification device. The suspension cooler adopts air cooling and directly uses fresh air for rapid cooling; one end of the suspension cooler is connected to the high-temperature induced draft fan, the other end of the suspension cooler is connected to the cyclone, one end of the high-temperature induced draft fan is connected to the hot air supplementary combustion furnace, and the extraction and purification equipment is respectively connected to the calcium carbide production line and the hot air supplementary combustion furnace; the hot air exiting the suspension cooler is heat-recovered and utilized, and is sent to the hot air supplementary combustion furnace through the high-temperature induced draft fan to provide the hot air required for combustion, rationally utilize the waste heat, and reduce the heat consumption required for heating the air;

[0054] The fuel of the hot air supplementary combustion furnace is carbon monoxide, a byproduct of the production of calcium carbide in the calcium carbide production line, which is sent to the furnace for combustion through a pipeline via carbon monoxide extraction and purification equipment.

[0055] In addition, preferably, the conveying equipment C in step 5 includes but is not limited to an air conveying chute to achieve rapid and safe conveying of carbide slag powder.

[0056] In addition, preferably, the homogenizing metering system is installed at the bottom of the lime storage in a detachable manner to facilitate inspection and maintenance.

[0057] In addition, preferably, the conveying equipment D is an air conveying chute and a bucket elevator to achieve fast and safe conveying and lifting of carbide slag powder.

[0058] A production process of a lime production system using carbide slag of the present invention comprises the following steps:

[0059] Step 1, the carbide slag powder in the carbide slag warehouse is measured by a metering device and then sent to the cyclone preheating system via a conveying device B;

[0060] Step 2: The cyclone preheating system preheats and removes impurities from the carbide slag powder to remove impurities in the carbide slag;

[0061] Step 3: The preheated carbide slag powder is sent to a cyclone calcination and decomposition system for calcination and decomposition;

[0062] Step 4: The calcined and decomposed lime product is sent to a suspension cooling system for cooling and collection;

[0063] Step 5: The finished lime products collected by the cyclone cooling system are sent to the lime warehouse for storage through the conveying equipment C;

[0064] Step 6: The lime powder coming out from the bottom of the lime storage is measured by the homogenization metering system and then sent to the granulation equipment through the conveying equipment D;

[0065] Step 7, the granulation equipment extrude and granulate the lime; Step 8, the prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as the raw material for calcium carbide production.

[0066] In addition, preferably, the water content of the carbide slag powder in step 1 is 6% or 7% or 8% or 9% or 10%; and the impurities removed from the carbide slag in step 2 include but are not limited to glass.

[0067] The present invention adopts advanced suspended preheating calcination and cooling technology to purify, calcine and shape carbide slag into granular calcium oxide, which is then returned to the carbide furnace to produce carbide, thereby realizing the circulation of calcium oxide in the chlor-alkali industry.

[0068] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0069] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A system for producing lime from carbide slag, characterized in that: It consists of carbide slag storage, metering equipment, conveying equipment A, conveying equipment B, conveying equipment C, conveying equipment D, homogenizing metering system, cyclone preheating system, cyclone calcining and decomposition system, suspension cooling system, lime storage, homogenizing metering system, granulating equipment and carbide production line; The carbide slag powder in the carbide slag warehouse is measured by a metering device and then sent to the cyclone preheating system via a conveying device B; The cyclone preheating system preheats and removes impurities from the carbide slag powder to remove impurities in the carbide slag. The carbide slag powder that has been cleaned and preheated is sent to a cyclone calcination and decomposition system for calcination and decomposition; The calcined and decomposed lime product is sent to a suspension cooling system for cooling and collection; The finished lime products collected by the cyclone cooling system are sent to the lime storage for storage via the conveying device C; The lime powder coming out from the bottom of the lime storage is measured by the homogenization metering system and then sent to the granulation equipment through the conveying equipment D; The granulation equipment extrudes and granulates the lime; The prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as a raw material for calcium carbide production.

2. A system for producing lime from carbide slag according to claim 1, characterized in that: The carbide slag warehouse is connected to a metering device; the metering device is connected to one end of a conveying device B; the other end of the conveying device B is connected to a cyclone preheating system; Among them, the metering equipment is a quantitative feeder; the conveying equipment B is a belt conveyor and a bucket elevator.

3. A system for producing lime from carbide slag according to claim 2, characterized in that: The cyclone preheating system includes a drying and dispersing machine, a powder selection and slag removal machine and a bag dust collector; the cyclone preheating system is connected to the bag dust collector, and the exhaust gas from the cyclone preheating system is purified by the bag dust collector before being discharged. The particles collected by the bag dust collector are undecomposed calcium hydroxide, which are sent to the kiln ash bin and then sent to the furnace for calcination again through the conveying equipment A; Among them, the calcium carbide slag powder transported by the conveying equipment B is first processed by the drying and disintegrating machine and then enters the powder selection and slag removal machine for further processing.

4. A system for producing lime from carbide slag according to claim 3, characterized in that: The cyclone calcination decomposition system comprises a decomposition furnace and a cyclone barrel, wherein the decomposition furnace is connected to a powder selection and slag removal machine and a cyclone barrel respectively; The carbide slag powder that has been preheated by the drying and disintegrating machine, the powder selecting and slag removing machine and the bag dust collector is sent to the decomposition furnace for suspended calcination. The finished lime product after calcination and decomposition enters the next stage cyclone for material and gas separation, and the high-temperature exhaust gas enters the upper cyclone preheating system to dry and preheat the carbide slag powder.

5. A system for producing lime from carbide slag according to claim 4, characterized in that: The suspension cooling system includes a suspension cooler, a high-temperature induced draft fan, a hot air supplementary combustion furnace and extraction and purification equipment. The suspension cooler adopts air cooling and directly uses fresh air for rapid cooling. One end of the suspension cooler is connected to the high-temperature induced draft fan, the other end of the suspension cooler is connected to the cyclone, one end of the high-temperature induced draft fan is connected to the hot air supplementary combustion furnace, and the extraction and purification equipment is connected to the calcium carbide production line and the hot air supplementary combustion furnace respectively; The hot air from the suspension cooler is recycled and sent to the hot air supplementary combustion furnace through a high-temperature induced draft fan to provide the hot air required for combustion; The fuel of the hot air supplementary combustion furnace is carbon monoxide, a byproduct of the production of calcium carbide in the calcium carbide production line, which is sent to the furnace for combustion through a pipeline via carbon monoxide extraction and purification equipment.

6. A system for producing lime from carbide slag according to claim 1, characterized in that: The conveying equipment C in step 5 includes but is not limited to an air conveying chute.

7. A system for producing lime from carbide slag according to claim 5, characterized in that: The homogenizing and metering system is installed at the bottom of the lime storage.

8. A system for producing lime from carbide slag according to claim 1, characterized in that: The conveying equipment D is an air conveying chute and a bucket elevator.

9. The production process of a carbide slag lime production system according to claim 1, characterized in that: The process includes the following steps, Step 1, the carbide slag powder in the carbide slag warehouse is measured by a metering device and then sent to the cyclone preheating system via a conveying device B; Step 2: The cyclone preheating system preheats and removes impurities from the carbide slag powder to remove impurities in the carbide slag; Step 3: The preheated carbide slag powder is sent to a cyclone calcination and decomposition system for calcination and decomposition; Step 4: The calcined and decomposed lime product is sent to a suspension cooling system for cooling and collection; Step 5: The finished lime products collected by the cyclone cooling system are sent to the lime warehouse for storage through the conveying equipment C; Step 6: The lime powder coming out from the bottom of the lime storage is measured by the homogenization metering system and then sent to the granulation equipment through the conveying equipment D; Step 7, the granulation equipment extrudes and granulates the lime; Step 8: The prepared granular calcium oxide is connected to the existing calcium carbide production line in the factory and used as a raw material for calcium carbide production; The water content of the carbide slag powder in step 1 is 6%-10%; the impurities removed from the carbide slag in step 2 include but are not limited to glass.

Images