Composite multi-process cement grinding system and process and cement production method

Abstract

The invention relates to the technical field of cement production and manufacturing, aims at solving the problems that an existing grinding system is single in function and cannot have multiple cement grinding processes at the same time, and provides a composite multi-process cement grinding system and process and a cement production method. Wherein the composite multi-process cement grinding system comprises a roller press grinding system and a ball mill grinding system, and the composite multi-process cement grinding process comprises three grinding processes, namely a combined grinding process, a semi-final grinding process and a final grinding process; the cement production method comprises the following steps: separately grinding clinker and a mixed material by using two sets of cement grinding systems, and then mixing by using a mixing system to obtain a finished product. According to the invention, the limitation of a single grinding system is broken through, the operability of the system is improved through an ingenious switching means, and the advantages and functions of production through one system and coexistence of multiple technological processes are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of cement production and manufacturing, and in particular to a composite multi-process cement grinding system, process and cement production method. Background Art

[0002] In the cement production process, cement grinding is the link with the highest energy consumption, and the grinding operation can directly affect the quality and quantity of cement production as well as technical and economic indicators; therefore, it is necessary to reasonably select different grinding systems for materials with different characteristics to reduce the power consumption of cement clinker grinding. When selecting a cement grinding system, in principle, grinding equipment with high grinding efficiency and low system energy consumption should be selected, which is also an important part of environmental protection and clean production.

[0003] The development of cement grinding system has undergone a process of continuous improvement and optimization from open circuit grinding to primary closed circuit grinding to roller press combined grinding to roller press combined semi-final grinding and roller press final grinding.

[0004] At present, the mainstream cement grinding process system mainly adopts roller press, disperser or V-type powder classifier, high-efficiency powder classifier, ball mill to form grinding systems with different configurations and different processes. The cement grinding process systems with obvious increase in production and energy saving include combined grinding system and semi-final grinding system.

[0005] Since cement produced by ball mills requires little water and has a wide particle size distribution, the properties of the cement produced are relatively superior. Ball mills are still the mainstream equipment for processing finished cement products. However, the power consumption of pure ball mills is too high. Adding a roller press grinding device in front of the ball mill is an important measure to save energy and reduce consumption in cement grinding systems. At present, the process systems for cement grinding mainly include combined grinding systems, semi-final grinding systems and final grinding systems. The main machines and process types configured in each grinding system are different and have their own characteristics.

[0006] The combined grinding process is as follows: after the prepared cement raw materials are squeezed by the roller press, the particle size and grindability of the materials change, and then they are sent to the powder selection equipment to select the semi-finished products as needed and enter the ball mill for further grinding to cement finished products. The materials that do not meet the requirements for entering the mill are returned to the roller press system for re-grinding until they meet the requirements and are selected for entering the mill. The combined grinding process effectively solves the problem of unstable and fluctuating particle size and grindability of the materials entering the mill, and has a good promoting effect on the stable operation of the roller press.

[0007] The combined grinding system is easy to operate, has a high output and low power consumption per unit product.

[0008] The semi-final grinding process is: select a part of the finished products with qualified fineness in the grinding system in advance and mix them with the finished products of the mill for storage. Select the finished products with qualified fineness in advance to avoid re-grinding, thereby improving the powder selection efficiency of the entire grinding system, reducing the "over-grinding" phenomenon, reducing the waste of grinding energy, and improving the grinding efficiency of the system. In fact, the main purpose of the semi-final grinding process is to directly add part of the fine powder collected by the roller press closed-circuit system into the finished cement product.

[0009] As a branch of the combined grinding system, the semi-final grinding system has a good effect of increasing production and reducing consumption. However, compared with the combined grinding system, its output is slightly higher and its power consumption is slightly lower. However, a part of the finished products directly selected from the semi-final grinding are not ground by the ball mill, and their sphericity is poor. The number of flaky and irregular particles increases, the particle distribution is unreasonable, and the product quality and adaptability are reduced, resulting in an increase in the water consumption of the standard consistency of the cement finished products entering storage and a deterioration in compatibility with admixtures.

[0010] The final grinding process is as follows: the material coming out of the roller press is sent to the powder classifier by the circulating elevator for sorting. The coarse material after sorting (the coarse material from the V-type powder classifier and the coarse material from the dynamic powder classifier) ​​returns to the roller press to be squeezed again, and the qualified cement product is carried by the wind into the cyclone dust collector for collection. There is no ball mill involved in the whole system.

[0011] The final grinding system has a simple structure and few equipments. Compared with the cement ground by ball mill, the cement produced has a narrow particle size distribution and poor sphericity, which leads to a large water demand, low fluidity and slightly poor cement adaptability of the final ground cement.

[0012] These three grinding systems have their own characteristics, advantages and disadvantages, but the combined grinding process is the most popular because of its advantages such as large finished product output, stable quality and low energy consumption. It has the most practical applications and has been widely used in cement production enterprises' cement grinding process technical transformation, expansion and new line construction projects. However, different companies and regions will still switch different production processes from time to time according to material characteristics and market demand. The most important thing is that the cement roller press final grinding system is the ultimate development direction of cement grinding and is the current dominant system for energy saving.

[0013] The above grinding systems have their own advantages and represent the three stages of cement grinding development. The first stage is the roller press grinding process, the second stage is the roller press semi-final grinding process, and the third stage is the roller press final grinding system. The purpose is to increase the proportion of roller press work, thereby further reducing the unit cement grinding power consumption. The general cement mill production workshop can only take into account one cement process flow, and it is impossible to integrate multiple processes in one cement mill workshop. The three processes cannot be adjusted accordingly according to the development of the market and technology. When the enterprise wants to change the grinding process, it must either modify the original workshop process or overturn and rebuild it, which undoubtedly greatly increases the equipment and civil engineering investment, and there is currently no cement grinding process that combines these three processes. Summary of the invention

[0014] The present invention aims to provide a composite multi-process cement grinding system, process and cement production method to solve the problem that the existing grinding system has a single function and cannot combine multiple cement grinding processes.

[0015] The present invention is achieved by adopting the following technical solutions:

[0016] The present invention provides a composite multi-process cement grinding system, comprising a roller press grinding system and a ball mill grinding system, wherein the roller press grinding system comprises a first steady flow bin, a roller press, a primary powder classifier, a first fine powder classifier, a cyclone dust collector, and a first fan connected in sequence; the ball mill grinding system comprises a ball mill, a second fine powder classifier, and a second chute;

[0017] The primary powder classifier is used to perform primary classification of materials, the coarse powder outlet of the primary powder classifier is connected to the feed port of the first stabilizing bin, and the first outlet of the primary powder classifier is connected to the feed port of the first fine powder classifier;

[0018] The coarse powder outlet of the first fine powder classifier is connected to the feed inlet of the first stabilizing bin and the ball mill grinding system, and a control valve is provided between the coarse powder outlet of the first fine powder classifier, the feed inlet of the first stabilizing bin and the ball mill grinding system; the medium coarse powder outlet of the first fine powder classifier is connected to the first stabilizing bin and the ball mill grinding system, and a control valve is provided between the medium coarse powder outlet of the first fine powder classifier, the first stabilizing bin and the ball mill grinding system; the air outlet of the first fine powder classifier is connected to the air inlet of the cyclone dust collector, and the discharge port of the cyclone dust collector is connected to the first chute;

[0019] The first chute is connected to the second chute and the ball mill grinding system, the second chute is connected to the finished product warehouse, and the first chute is provided with a first regulating valve, the first regulating valve is used to regulate the first chute to control it to be connected to the second chute or the ball mill grinding system;

[0020] The finished product outlet of the second fine powder classifier is connected to the second chute, and the ball mill is connected to the second fine powder classifier and the second chute through the fifth chute. The fifth chute is provided with a second regulating valve, and the second regulating valve is used to adjust the fifth chute to control it to be connected to the second fine powder classifier or the second chute.

[0021] The coarse powder outlet of the first-stage powder classifier is connected to the feed port of the first stabilizing bin, so as to return the coarse powder with larger particles to the first stabilizing bin and then re-grind it through the roller press; the first outlet of the first-stage powder classifier is used to pass materials other than coarse powder and transport them to the first fine powder classifier for secondary sorting. The particle size of the coarse powder with larger particles is set according to actual conditions.

[0022] The coarse powder outlet of the first fine powder classifier is connected to the feed inlet of the first stabilizing bin and the ball mill grinding system, and a control valve is provided between the coarse powder outlet of the first fine powder classifier, the feed inlet of the first stabilizing bin and the ball mill grinding system. After the second sorting by the first fine powder classifier, the coarse powder selected by the first fine powder classifier can be returned to the first stabilizing bin and then re-grinded by the roller press, or can enter the ball mill grinding system for further grinding, which can be achieved by adjusting the corresponding control valve;

[0023] The medium-coarse powder outlet of the first fine powder classifier is connected to the first steady flow bin and the ball mill grinding system, and a control valve is provided between the medium-coarse powder outlet of the first fine powder classifier, the first steady flow bin and the ball mill grinding system. The medium-coarse powder selected by the first fine powder classifier can all return to the first steady flow bin and then be re-ground by the roller press, or a part of it can enter the roller press and a part of it can enter the ball mill grinding system for grinding, which can be achieved by adjusting the corresponding control valve;

[0024] The air outlet of the first fine powder classifier is connected to the air inlet of the cyclone dust collector, and fine powder is collected by the cyclone dust collector; the discharge port of the cyclone dust collector is connected to the first chute, the first chute is connected to the second chute and the ball mill grinding system, the second chute is connected to the finished product warehouse, and the first regulating valve is used to adjust the first chute so that the fine powder can enter the ball mill grinding system for further grinding, or directly enter the finished product warehouse through the second chute.

[0025] Based on this, three cement grinding processes can be realized through the above-mentioned composite multi-process cement grinding system, namely, combined grinding process, semi-final grinding process, and final grinding process;

[0026] The combined grinding process is: controlling the coarse powder and medium coarse powder selected by the first fine powder classifier to enter the roller press together, and controlling the fine powder collected by the cyclone dust collector to enter the ball mill grinding system for further grinding;

[0027] The semi-final grinding process is as follows: the coarse powder selected by the first fine powder classifier is controlled to enter the roller press, a part of the selected medium and coarse powder enters the roller press, and a part enters the ball mill grinding system, and the fine powder collected by the cyclone dust collector is used as the finished product, and the fine powder is transported to the second chute through the first chute to the finished product warehouse as the finished product;

[0028] The final grinding process is: control the coarse powder and medium coarse powder selected by the first fine powder classifier to all enter the roller press, and use the fine powder collected by the cyclone dust collector as the finished product, and the fine powder is transported to the finished product warehouse through the first chute into the second chute to make the finished product.

[0029] Since the coarse powder outlet of the first fine powder classifier is also connected to the ball mill grinding system, in the actual production process, when the amount of coarse powder collected by the first fine powder classifier is too much, a part of the coarse powder can be passed through the control valve to the ball mill grinding system for grinding, so as to ensure the normal operation of the roller press; since the medium coarse powder outlet of the first fine powder classifier is connected to the first steady flow bin, when the amount of medium coarse powder collected by the first fine powder classifier is too much, more medium coarse powder can be passed through the control valve to the roller press for grinding, so as to ensure that the ball mill system does not have saturation. Such a design makes the system more flexible, has the function of emergency treatment, and ensures the continuity of the grinding process.

[0030] Furthermore, the ball mill grinding system of the present invention includes a ball mill, a second fine powder classifier and a second chute, the finished product outlet of the second fine powder classifier is connected to the second chute, the ball mill is connected to the second fine powder classifier and the second chute through a fifth chute, and the fifth chute is adjusted by a second regulating valve so that the material ground by the ball mill enters the second fine powder classifier for powder selection, and the selected finished product enters the finished product warehouse through the second chute, or directly enters the finished product warehouse through the second chute.

[0031] Based on this, the combined grinding process and final grinding process including the grinding of the ball mill system can be further divided into an open-circuit process and a closed-circuit process. The material ground by the ball mill enters the second fine powder concentrator for sorting, which is a closed-circuit process, and directly enters the finished product warehouse through the second chute, which is an open-circuit process. Combining the above processes, a total of five processes are included.

[0032] The present invention breaks the limitation of a single grinding system, improves the operability of the system through clever switching means, and realizes the advantages and functions of coexistence of multiple process flows through one system production, making advance preparations for realizing the ultimate process flow of "ball-free grinding" for cement grinding. Cement companies can choose which process to use according to their own specific conditions, which can not only improve equipment utilization, but also improve grinding efficiency and reduce production costs to benefit the company's future economic benefits.

[0033] As the preferred technical solution:

[0034] The first-stage powder classifier adopts a V-type powder classifier.

[0035] As the preferred technical solution:

[0036] A dividing valve is provided between the coarse powder outlet of the first fine powder classifier and the first stabilizing bin, the feed end of the dividing valve is connected to the coarse powder outlet of the first fine powder classifier, and the discharge end of the dividing valve is connected to the feed port of the first stabilizing bin and the ball mill grinding system.

[0037] The coarse powder selected by the first fine powder classifier enters the distributing valve from the feed end of the distributing valve, and then enters the feed port of the first stabilizing bin or the ball mill grinding system from the discharge end of the distributing valve to meet the needs of the combined grinding process, the semi-final grinding process and the final grinding process. When the amount of coarse powder collected by the first fine powder classifier is too much, a part of the coarse powder can be passed through the distributing valve into the ball mill grinding system for grinding. The distributing valve is a control valve arranged between the coarse powder outlet of the first fine powder classifier and the feed port of the first stabilizing bin and the ball mill grinding system.

[0038] As the preferred technical solution:

[0039] The ball mill grinding system also includes a second flow stabilization bin and a rotor scale. The second flow stabilization bin, the rotor scale and the ball mill are connected in sequence. The discharge end of the material distribution valve is connected to the feed port of the rotor scale.

[0040] The coarse powder selected by the first fine powder classifier can enter the rotor scale through the material distribution valve, and then enter the ball mill grinding system for grinding.

[0041] As the preferred technical solution:

[0042] A first control valve is provided between the medium-coarse powder outlet of the first fine powder classifier and the dividing valve, and a second control valve is provided between the medium-coarse powder outlet of the first fine powder classifier and the second stabilizing bin.

[0043] By controlling the dividing valve, the first control valve and the second control valve, the medium and coarse powder selected by the first fine powder classifier can all enter the dividing valve through the first control valve, and then by adjusting the dividing valve, the medium and coarse powder can all enter the first steady flow bin and be ground by the roller press; the medium and coarse powder selected by the first fine powder classifier can also partially enter the roller press, and partially enter the ball mill for grinding through the second steady flow bin and the rotor scale. When the amount of medium and coarse powder collected by the first fine powder classifier is too much, by adjusting the dividing valve, more medium and coarse powder can be passed through the dividing valve into the roller press for grinding, ensuring that the ball mill system does not have saturation grinding, so as to meet the needs of combined grinding process, semi-final grinding process and final grinding process.

[0044] As the preferred technical solution:

[0045] The first control valve and the second control valve are gate valves.

[0046] As the preferred technical solution:

[0047] As the preferred technical solution:

[0048] The first flow stabilization bin and the second flow stabilization bin are weighing flow stabilization bins.

[0049] As the preferred technical solution:

[0050] The first regulating valve and the second regulating valve are electric dispensing valves.

[0051] As the preferred technical solution:

[0052] The cyclone dust collector adopts a double cyclone dust collector.

[0053] As the preferred technical solution:

[0054] The first fine powder classifier adopts a three-separation high-efficiency powder classifier, and the second fine powder classifier adopts a T-sepax high-efficiency three-separation powder classifier.

[0055] As the preferred technical solution:

[0056] A first elevator is provided between the roller press and the primary powder classifier, and the first elevator is used to lift and transport the material ground by the roller press to the primary powder classifier;

[0057] The ball mill is connected to the fourth chute, and a second elevator is arranged between the fourth chute and the fifth chute, and the second elevator is used to lift and transport materials to the fifth chute.

[0058] The materials are lifted and transported by elevator.

[0059] As the preferred technical solution:

[0060] The finished product outlet of the second fine powder classifier is connected to the second chute through the sixth chute, and the second outlet of the second fine powder classifier is connected to the ball mill through the third chute.

[0061] The second outlet is used to feed unqualified powder into the ball mill through the third chute for re-grinding.

[0062] As the preferred technical solution:

[0063] The air outlet of the first fan is connected to the air inlet of the first-stage powder classifier and the air inlet of the first dust collector, the air outlet of the first dust collector is connected to the air inlet of the second fan, and the discharge port of the first dust collector is connected to the second chute through the seventh chute.

[0064] The present invention sets a dust collection system behind the first fine powder concentrator, so that the system has the function of independently producing cement with a roller press, avoiding sharing the air path with the ball mill system. The roller press grinding system is equipped with an independent dust removal system, which can bypass the ball mill grinding system to achieve the roller press final grinding method.

[0065] As the preferred technical solution:

[0066] The air inlet of the first-stage powder classifier is provided with a first cold air valve; the outlet of the second fine powder classifier is provided with a second cold air valve.

[0067] By adding fresh air through the cold air valve, the material temperature can be lowered to avoid the phenomenon of material hardening due to dehydration caused by high temperature when transported to the finished product warehouse.

[0068] As the preferred technical solution:

[0069] The outlet end of the ball mill is connected to the air inlet of the second dust collector, the air outlet of the second dust collector is connected to the air inlet of the third fan, the first discharge port of the second dust collector is connected to the second chute, and the second discharge port of the second dust collector is connected to the fourth chute;

[0070] The second fine powder classifier is connected to the air inlet of the third dust collector, the air outlet of the third dust collector is connected to the air inlet of the fourth fan, and the discharge port of the third dust collector is connected to the finished product warehouse through the second chute.

[0071] The ball mill is independently designed with a ventilation dust collector and a dust collecting fan to reduce dust emission during the grinding process, meet environmental protection requirements, and also recycle powder. The second fine powder concentrator is also independently designed with a ventilation dust collector and a dust collecting fan.

[0072] The present invention further provides a composite multi-process cement grinding process, which utilizes the composite multi-process cement grinding system to grind cement, including three grinding processes, namely, a combined grinding process, a semi-final grinding process, and a final grinding process;

[0073] The combined grinding process is: the coarse powder and medium coarse powder collected by the first fine powder classifier are controlled to enter the roller press, and the fine powder collected by the cyclone dust collector is controlled to enter the ball mill for further grinding;

[0074] The semi-final grinding process is as follows: the coarse powder collected by the first fine powder classifier is controlled to enter the roller press, and part of the medium and coarse powder collected by the first fine powder classifier is controlled to enter the roller press and part of it to enter the ball mill, and the fine powder collected by the cyclone dust collector is used as the finished product, and the fine powder is collected into the second chute through the first chute and transported to the finished product warehouse as the finished product;

[0075] The final grinding process is as follows: the coarse powder and medium coarse powder collected by the first fine powder classifier are controlled to enter the roller press, and the fine powder collected by the cyclone dust collector is used as the finished product, and the fine powder is collected into the second chute through the first chute and transported to the finished product warehouse as the finished product;

[0076] For the combined grinding process and the semi-final grinding process, they include an open circuit process and a closed circuit process respectively;

[0077] The closed-circuit process is: the materials ground by the ball mill are controlled to enter the second fine powder concentrator for sorting, and the qualified materials after sorting enter the finished product warehouse through the second chute;

[0078] The open circuit process is to control the materials ground by the ball mill to directly enter the finished product warehouse through the second chute.

[0079] In the present invention, the fine powder collected by the first fine powder classifier is particles with a particle size of less than 30 μm, the medium coarse powder is particles with a particle size of 30 to 200 μm, and the coarse powder is coarse particles with a particle size of more than 200 μm.

[0080] The present invention further provides a cement production method, comprising the following steps:

[0081] S1. Arrange two sets of the above-mentioned composite multi-process cement grinding systems in the cement grinding workshop, namely cement grinding system 1 and cement grinding system 2. Each cement grinding system can switch to multiple modes, and use the two cement grinding systems to grind clinker and mixed materials separately;

[0082] S2, the ground clinker and mixed materials are stored separately in storage 1 and storage 2 respectively;

[0083] S3. According to the different types of cement produced, the amount of clinker and mixed materials is controlled by a metering scale in the mixing system, and the two are sent together into the mixing system for mixing of cement types; the finished products are transported to the cement finished product warehouse system for separate storage.

[0084] As the preferred technical solution:

[0085] In step S1, mode three final grinding mode is used to grind single materials separately, especially clinker which is difficult to grind. The particle size of clinker powder needs to be controlled during grinding. Mixed materials are ground separately and the particle size is controlled as needed.

[0086] The working principle of the present invention is as follows: the materials from the cement batching and conveying system are transported to the first elevator through the feeding belt conveyor, and then are lifted to the first steady flow bin by the first elevator and fed to the roller press for grinding; after being ground by the roller press, the materials are transported to the primary powder classifier through the first elevator for breaking and sorting, and the large-particle coarse powder is selected and returned to the roller press for further grinding, and the other materials enter the first fine powder classifier for secondary sorting;

[0087] The coarse powder selected by the first fine powder classifier is returned to the roller press for secondary grinding, the medium-coarse powder can be returned to the roller press for secondary grinding, or it can enter the ball mill and return to the roller press for further grinding in a certain proportion; the fine powder selected by the first fine powder classifier is collected by the cyclone dust collector, and the fine powder can be made into finished products and sent to the finished product warehouse, or it can be returned to the ball mill for further grinding.

[0088] The coarse powder and medium coarse powder collected by the first fine powder classifier are fed into the roller press together, while the fine powder is fed into the ball mill for further grinding, which is called the combined grinding process. Since the crushing function of the ball mill is relatively weak but the fine grinding ability is relatively strong, the grinding system of the roller press reduces the particle size of the material entering the ball mill, thereby improving the grinding efficiency of the ball mill. Moreover, the coarse powder with a size of >200μm is fed back to the roller press, which can significantly reduce the maximum particle size of the material entering the ball mill and improve the efficiency of the roller press.

[0089] The coarse powder collected by the first fine powder selector enters the roller press, and part of the medium coarse powder enters the roller press and part of the ball mill. The qualified fine powder selected is the finished product, which is collected by the cyclone dust collector and then merged into the second chute to be transported to the finished product warehouse as the finished product, which is the semi-final grinding process; the semi-final grinding process selects the powder produced by the roller press that meets the fineness of the cement finished product in advance, and then mixes it with the cement finished product ground by the ball mill to form the final cement product. This part of the pre-selected finished product does not pass through the ball mill to grind, which can reduce the burden of the ball mill and the ratio of over-grinded materials, thereby improving the system grinding efficiency, and can greatly reduce the over-grinding phenomenon of the mill, thereby increasing the system output and reducing the system grinding power consumption. In the semi-final grinding process, the cement finished product directly selected by the roller press extrusion grinding has certain differences in particle size distribution and particle morphology from the cement finished product prepared by the ball mill, which often leads to a large water demand for the cement finished product, which increases the difficulty of concrete preparation and does not meet the needs of mixing stations in some areas. At present, some areas are using this process.

[0090] The coarse powder and medium coarse powder collected by the first fine powder selector enter the roller press, while the fine powder is collected by the cyclone dust collector and then directly transported to the finished product warehouse through the second chute to make the finished product, which is the final grinding process. Compared with the cement ground by the ball mill, the cement produced by the final grinding process has a narrow particle size distribution and poor sphericity, resulting in problems such as large water demand and low fluidity in the final ground cement. In response to this problem, it is necessary to grind the clinker and various admixtures in each type of cement separately. The separate grinding production method can produce clinker powder and various admixture powders of uniform standards, avoiding the phenomenon of over-grinding. The fineness can be controlled according to the characteristics of the clinker and admixture, and they can be stored separately and then mixed to make various types of cement, so that the particle gradation of the finished cement produced is more reasonable and the amount of clinker is more economical.

[0091] The ball mill grinding system in the combined grinding process and semi-final grinding process is equipped with a T-sepax high-efficiency three-separation powder classifier. The material discharged from the ball mill is lifted to the fifth chute by the second elevator. The fifth chute is provided with a second regulating valve. The material discharged from the mill can enter the T-sepax high-efficiency three-separation powder classifier for sorting, which is a closed-circuit process, or directly enter the second chute to the finished product warehouse, which is an open-circuit process. The advantages and disadvantages of the open-circuit closed-circuit process are obvious: the temperature of the closed-circuit can be controlled, and the fineness can be controlled. When the temperature is high in summer or the clinker temperature is high, a closed-circuit process is adopted. The cement is cooled by the cold air of the matching T-sepax high-efficiency three-separation powder classifier, so that the cement entering the warehouse is below 70°C for a long time, avoiding the cement in the warehouse from dehydration and agglomeration due to gypsum, which is conducive to cement discharge and improving cement performance; the particle grading of the open-circuit is stronger than that of the closed-circuit. The particle distribution of the closed-circuit milled cement is narrow, so the water demand is large, and the particle distribution of the open-circuit milled cement is wide, so the water demand is small. The fineness of cement tends to be coarse when it is ground in an open circuit, so the flow rate in the mill cannot be too fast, which results in the heat in the mill not being discharged in time, the temperature of the cement leaving the mill is high, the gypsum is dehydrated, and in severe cases, the cement is falsely set.

[0092] Through the composite multi-process grinding process optimized and designed by the above system, the combined grinding process of the roller press and the semi-final grinding process correspond to the open and closed modes of the ball mill system respectively, combining four process flows. Together with the independent roller press final grinding system, there are a total of five cement production process flows. According to the material conditions and market demand, the production can be switched through multiple processes to improve the working efficiency of the roller press, the grinding efficiency of the ball mill and the powder selection efficiency of the powder classifier, which provides a guarantee for the cement grinding system to increase production and reduce consumption, so that the system has lower power consumption in the grinding process, greatly reduces the cement grinding preparation cost, and makes advance preparations for the ultimate process of realizing cement grinding "without ball milling".

[0093] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0094] 1. The composite multi-process cement grinding system of the present invention can composite multi-process cement grinding technology, so that a variety of different grinding process flows are integrated in one cement grinding workshop, and a cement grinding process with multiple grinding processes coexisting is derived, so that the production process in a cement grinding workshop can be switched between combined grinding (open circuit and closed circuit), semi-final grinding process (open circuit and closed circuit), and final grinding, breaking the limitation of a single grinding system; the entire system of the grinding workshop can flexibly switch different processes according to market conditions, and the operation control is flexible and changeable, which improves the market adaptability of the cement mill.

[0095] 2. The present invention can connect two sets of such process flows in parallel in a cement grinding workshop, use the final grinding process mode to grind materials such as clinker and mixed materials separately, store them separately, and then mix the ground single raw materials into qualified cement products of different varieties. It not only avoids the over-grinding phenomenon, but also realizes the adjustment and optimization of the particle distribution of different materials, and obtains better cement particle grading and characteristics to meet the requirements of cement performance. This process can greatly improve the grinding efficiency and reduce the power consumption of cement grinding.

[0096] 3. In the roller press grinding system of the present invention, a three-separation high-efficiency powder classifier is added between the V-type powder classifier and the cyclone dust collector. The three-separation high-efficiency powder classifier with bottom air inlet takes into account the powder selection needs of cement semi-finished products and cement finished products, realizes accurate grading and sorting, and improves the utilization rate of the equipment.

[0097] 4. In the roller press grinding system of the present invention, a dust collecting system is separately arranged after the cyclone dust collector, and its air path operates independently, so that the roller press system can be produced independently, so that the function of the roller press is fully exerted. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 It is a schematic structural diagram of the composite multi-process cement grinding system described in the present invention.

[0099] Figure 2 This is a schematic structural diagram of the composite multi-process cement grinding system of the present invention (mode one: roller press + closed-circuit tube mill combined grinding process).

[0100] Figure 3 This is the flow chart of mode 1 of the present invention: roller press + closed-circuit tube mill combined grinding process.

[0101] Figure 4 It is a structural schematic diagram of the composite multi-process cement grinding system described in the present invention (mode one: roller press + open circuit cement tube mill combined grinding process).

[0102] Figure 5 This is the flow chart of mode 1 of the present invention: roller press + open circuit cement tube mill combined grinding process.

[0103] Figure 6 This is a schematic structural diagram of the composite multi-process cement grinding system of the present invention (mode two: roller press + closed-circuit tube mill semi-final grinding process).

[0104] Figure 7 This is the flow chart of mode 2 of the present invention: roller press + closed-circuit tube mill semi-final grinding process.

[0105] Figure 8It is a structural schematic diagram of the composite multi-process cement grinding system described in the present invention (mode two: roller press + open circuit cement tube mill semi-final grinding process).

[0106] Fig. 9 This is the flow chart of mode 2 of the present invention: roller press + open circuit cement tube mill semi-final grinding process.

[0107] Fig.10 This is a schematic structural diagram of the composite multi-process cement grinding system described in the present invention (mode three: roller press final grinding process).

[0108] Fig.11 This is mode three of the present invention: a flow chart of the roller press final grinding process.

[0109] Fig.12 The present invention is a flow chart of the cement production method.

[0110] Icons: 1-first elevator, 2-first weighing and stabilizing bin, 3-roller press, 4-second elevator, 5-V-type powder classifier, 6-three-separation high-efficiency powder classifier, 7-double cyclone dust collector, 8-first fan, 9-first dust collector, 10-second fan, 11-first chute, 12-second chute, 13-third chute, 14-second weighing and stabilizing bin, 15-rotor scale, 16-ball mill, 17-fourth chute, 18-third elevator , 19-fifth chute, 20-T-sepax high-efficiency three-separation powder classifier, 21-sixth chute, 22-seventh chute, 23-second dust collector, 24-third fan, 25-third dust collector, 26-fourth fan, 27-distribution valve, 28-first gate valve, 29-second gate valve, 30-first electric distribution valve, 31-second electric distribution valve, 32-first cold air valve, 33-second cold air valve, 34-fifth fan. DETAILED DESCRIPTION

[0111] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0112] Example 1

[0113] like Figure 1 As shown, this embodiment proposes a composite multi-process cement grinding system, including a roller press grinding system and a ball mill grinding system, wherein the roller press grinding system is arranged on one side of the ball mill grinding system.

[0114] Among them, the roller press grinding system includes a first elevator 1, a first weighing stabilizing bin 2, a roller press 3, a second elevator 4, a V-type powder classifier 5, a three-separation high-efficiency powder classifier 6, a double cyclone dust collector 7, a first fan 8, a first dust collector 9, a second fan 10, a first chute 11, a first electric material distribution valve 30, and a first cold air valve 32.

[0115] The discharge port of the first elevator 1 corresponds to the feed port of the first weighing and stabilizing bin 2, and the first elevator 1 is used to lift and transport the raw materials to the first weighing and stabilizing bin 2. The discharge port of the first weighing and stabilizing bin 2 is connected to the feed port of the roller press 3, and the materials enter the roller press 3 for grinding. The discharge port of the roller press 3 corresponds to the feed port of the second elevator 4, and the discharge port of the second elevator 4 corresponds to the feed port of the V-type powder selector 5. The second elevator 4 is used to lift and transport the materials ground by the roller press 3 to the V-type powder selector 5, and the V-type powder selector 5 performs primary sorting on the materials. The coarse powder outlet of the V-type powder selector 5 is connected to the feed port of the first weighing and stabilizing bin 2, and at the same time, the first outlet of the V-type powder selector 5 is connected to the feed port of the three-separation high-efficiency powder selector 6, and the first outlet is used to pass other materials after the coarse powder is removed. The coarse powder outlet of the three-separation high-efficiency powder classifier 6 is connected to the feed port of the first weighing stabilizing flow bin 2 and the ball mill grinding system. The coarse powder is usually returned to the first weighing stabilizing flow bin 2 and then re-ground by the roller press 3. When the amount of coarse powder collected by the three-separation high-efficiency powder classifier 6 is too much, a part of the coarse powder can be passed into the ball mill grinding system for grinding to ensure the normal operation of the roller press 3; the medium coarse powder outlet of the three-separation high-efficiency powder classifier 6 is connected to the first weighing stabilizing flow bin 2 and the ball mill grinding system. The system is connected, the medium and coarse powder can all return to the first weighing steady flow bin 2, and then be re-grinded by the roller press 3, or a part of it can enter the roller press 3 and a part of it can enter the ball mill grinding system for grinding; the air outlet of the three-separation high-efficiency powder selector 6 is connected to the double cyclone dust collector 7, the exhaust port of the double cyclone dust collector 7 is connected to the first fan 8, and the discharge port of the double cyclone dust collector 7 is connected to the first chute 11, so that the fine powder is transported to the first chute 11. The first electric material distribution valve 30 is also installed on the first chute 11. The air outlet of the first fan 8 is connected to the air inlet of the V-type powder selector 5 and the air inlet of the first dust collector 9, and the air outlet of the first dust collector 9 is connected to the air inlet of the second fan 10. The air inlet of the V-type powder selector 5 is connected to the first cold air valve 32.

[0116] The materials from the cement batching and conveying system are transported to the first elevator 1 through the feeding belt conveyor, and are lifted and transported to the first weighing steady flow bin 2 through the first elevator 1, and then enter the roller press 3 for extrusion and crushing. The crushed materials are lifted by the second elevator 4 and sent to the V-type powder classifier 5 for dispersion and primary sorting. The coarse powder with larger particles returns to the roller press 3 for roller grinding again, and the remaining selected materials are subjected to secondary sorting by the three-separation high-efficiency powder classifier 6. This cyclone adopts a downward air intake mode and a two-stage powder selection method to select coarse powder and medium coarse powder. The fine powder is collected by the double cyclone dust collector 7, and part of the exhaust gas passes through the first fan 8 and returns to the V-type powder classifier 5 for powder selection again, and part enters the first dust collector 9 for dust collection. The purified gas is discharged through the second fan 10, wherein the air temperature of the roller press grinding system can be adjusted by the first cold air valve 32.

[0117] The ball mill grinding system includes a second chute 12, a third chute 13, a second weighing stabilizing bin 14, a rotor scale 15, a ball mill 16, a fourth chute 17, a third elevator 18, a fifth chute 19, a T-sepax high-efficiency three-separation powder classifier 20, a sixth chute 21, a seventh chute 22, a second dust collector 23, a third fan 24, a third dust collector 25, a fourth fan 26, a distributing valve 27, a first gate valve 28, a second gate valve 29, a second electric distributing valve 31, a second cold air valve 33, and a fifth fan 34.

[0118] The second weighing stabilizing bin 14, the rotor scale 15, and the ball mill 16 are connected in sequence, the discharge port of the second weighing stabilizing bin 14 is connected to the feed port of the rotor scale 15, and the discharge port of the rotor scale 15 is connected to the feed port of the ball mill 16. The second chute 12 is connected to the finished product warehouse, the first chute 11 is located above the second chute 12, and the first chute 11 is respectively connected to the second weighing stabilizing bin 14 and the second chute 12 through the first electric material distribution valve 30, so the fine powder collected by the double cyclone dust collector 7 can be directly transported to the finished product warehouse through the first chute 11 and the second chute 12, and can also enter the second weighing stabilizing bin 14 and then continue to be ground through the ball mill 16.

[0119] The coarse powder outlet of the three-separation high-efficiency powder classifier 6 is connected to the dividing valve 27, the feed end of the dividing valve 27 is connected to the coarse powder outlet of the three-separation high-efficiency powder classifier 6, and the discharge end of the dividing valve 27 is connected to the feed port of the rotor scale 15 and the feed port of the first weighing stabilizing bin 2. In this embodiment, the dividing valve 27 is installed on the chute of the three-separation high-efficiency powder classifier 6 to control the direction of the selected powder.

[0120] The coarse powder selected by the three-separation high-efficiency powder classifier 6 usually enters the first weighing steady flow bin 2 through the dividing valve 27, and then is re-ground by the roller press 3. When the amount of coarse powder collected by the three-separation high-efficiency powder classifier 6 is too much, a part of the coarse powder can be controlled by the dividing valve 27 to enter the rotor scale 15, and then enter the ball mill 16 for grinding to ensure the normal operation of the roller press 3.

[0121] The medium and coarse powder outlet of the three-separation high-efficiency powder classifier 6 is connected to the dividing valve 27 through the first gate valve 28 on the one hand, and is connected to the feed port of the second weighing stabilizing bin 14 through the second gate valve 29 on the other hand.

[0122] The medium and coarse powder selected by the three-separation high-efficiency powder selector 6 can all be returned to the first weighing steady flow bin 2, and then re-grinded by the roller press 3, or a part of it can enter the roller press 3 and a part of it can enter the ball mill 16 for further grinding. When the amount of medium and coarse powder collected by the three-separation high-efficiency powder selector 6 is too much, more medium and coarse powder can be passed into the roller press 3 for grinding through the dividing valve 27 to ensure that the ball mill 16 does not have saturation grinding phenomenon.

[0123] The discharge port of the ball mill 16 is connected to the feed port of the fourth chute 17, the discharge port of the fourth chute 17 is connected to the feed port of the third elevator 18, the discharge port of the third elevator 18 is connected to the feed port of the fifth chute 19, and the third elevator 18 is used to lift and transport the material ground by the ball mill 16 to the fifth chute 19.

[0124] The T-sepax high-efficiency three-separation powder concentrator 20 and the second chute 12 are arranged below the fifth chute 19, the sixth chute 21 is arranged between the T-sepax high-efficiency three-separation powder concentrator 20 and the second chute 12, the finished product outlet of the T-sepax high-efficiency three-separation powder concentrator 20 is connected to the sixth chute 21, and the outlet end of the sixth chute 21 is connected to the second chute 12. The fifth chute 19 is provided with a second electric dispensing valve 31, and the fifth chute 19 is connected to the T-sepax high-efficiency three-separation powder concentrator 20 and the second chute 12 through the second electric dispensing valve 31. The material ground by the ball mill 16 can be directly transported to the finished product warehouse through the fifth chute 19 and the second chute 12, and can also be transported to the finished product warehouse through the fifth chute 19, the T-sepax high-efficiency three-separation powder concentrator 20, and the second chute 12.

[0125] The third chute 13 is also provided below the T-sepax high-efficiency three-separation powder selector 20, the second outlet of the T-sepax high-efficiency three-separation powder selector 20 is connected to the third chute 13, and the outlet end of the third chute 13 is connected to the feed port of the ball mill 16. The qualified finished products selected by the T-sepax high-efficiency three-separation powder selector 20 are transported to the second chute 12 through the finished product outlet, and the unqualified powder is transported to the ball mill 16 through the second outlet for re-grinding.

[0126] The outlet end of the ball mill 16 is connected to the air inlet of the second dust collector 23, the air outlet of the second dust collector 23 is connected to the air inlet of the third fan 24, the first discharge port of the second dust collector 23 is connected to the second chute 12, and the second discharge port of the second dust collector 23 is connected to the fourth chute 17.

[0127] The T-sepax high-efficiency three-separation powder selection machine 20 is connected to the air inlet of the third dust collector 25, the air outlet of the third dust collector 25 is connected to the air inlet of the fourth fan 26, and the discharge port of the third dust collector 25 is connected to the finished product warehouse through the second chute 12. The air outlet of the T-sepax high-efficiency three-separation powder selection machine 20 is also connected to the air inlet of the fifth fan 34, and the air outlet of the fifth fan 34 is connected to the air inlet of the third dust collector 25. The outlet of the T-sepax high-efficiency three-separation powder selection machine 20 is provided with a second cold air valve 33.

[0128] The discharge port of the first dust collector 9 is connected to the seventh chute 22, the seventh chute 22 is located above the second chute 12, the outlet end of the seventh chute 22 corresponds to the second chute 12, and the discharge port of the first dust collector 9 is connected to the finished product warehouse through the seventh chute 22 and the second chute 12.

[0129] After the material passes through the roller press grinding system, the coarse powder usually enters the first weighing stabilizing flow bin 2 through the dividing valve 27, and then enters the roller press 3 for grinding. When the amount of coarse powder collected by the three-separation high-efficiency powder selector 6 is too much, the dividing valve 27 can be used to control a part of the coarse powder to enter the rotor scale 15, and then enter the ball mill 16 for fine grinding. On the one hand, the medium coarse powder can enter the first weighing stabilizing flow bin 2 through the dividing valve 27 and the first gate valve 28, and then enter the roller press 3 for grinding. On the other hand, it can enter the second weighing stabilizing flow bin 14 through the second gate valve 29, and then enter the rotor scale 15 and the ball mill 16 for grinding. On the one hand, the fine powder can be transported to the finished product warehouse through the first chute 11 and the second chute 12, and on the other hand, it can enter the second weighing stabilizing flow bin 14 for metering and stabilization through the control of the first electric dividing valve 30. After entering the second weighing stabilizing bin 14, the material enters the rotor scale 15 for fine metering of the mill weight, and then enters the ball mill 16 for fine grinding. After grinding, it is transported to the third elevator 18 through the fourth chute 17, and then transported through the fifth chute 19. The direction of material transportation is controlled by the second electric material distribution valve 31. On the one hand, the material can enter the T-sepax high-efficiency three-separation powder classifier 20 for three-level sorting, and the qualified finished products selected enter the sixth chute 21 and merge into the second chute 12 to be transported to the finished product warehouse. The unqualified powder selected is then fed through the third chute 13 into the ball mill 16 for re-grinding to form closed-circuit grinding. On the other hand, the material after passing through the roller press grinding system can also be directly transported to the finished product warehouse through the second chute 12 to form open-circuit grinding. These two processes can be switched at will according to actual production conditions. The exhaust gas in the mill is purified by the second dust collector 23 and discharged by the third fan 24, while the exhaust gas from the T-sepax high-efficiency three-separation powder classifier 20 is purified by the third dust collector 25 and discharged by the fourth fan 26, wherein the air temperature in the powder selection system can be adjusted by the second cold air valve 33.

[0130] In the present invention, fine powder refers to particles with a particle size of less than 30 μm, medium coarse powder refers to particles with a particle size of 30 to 200 μm, and coarse powder refers to coarse particles with a particle size of more than 200 μm.

[0131] like Figure 2 and Figure 3As shown, when the coarse powder collected by the three-separation high-efficiency powder classifier 6 is controlled by the dividing valve 27 to return to the first weighing steady flow bin 2 and then enter the roller press 3 for further grinding, the medium-coarse powder is controlled by the first gate valve 28 to enter the first weighing steady flow bin 2 and then enter the roller press 3 for further grinding, and the fine powder collected by the double cyclone dust collector 7 is controlled by the first electric dividing valve 30 to enter the second weighing steady flow bin 14, and then enter the ball mill 16 for further grinding after being measured by the rotor scale 15. The ground material passes through the fourth chute 17, the third elevator 18, and the fifth chute 19 to enter the T-sepax high-efficiency three-separation powder classifier 20 for powder selection, which is the mode 1 combined grinding process of the present invention, specifically the roller press + closed-circuit tube mill combined grinding;

[0132] like Figure 4 and Figure 5 As shown, when the coarse powder collected by the three-separation high-efficiency powder selector 6 is controlled by the dividing valve 27 to return to the first weighing stabilizing flow bin 2 and then enter the roller press 3 for further grinding, the medium-coarse powder is controlled by the first gate valve 28 to enter the first weighing stabilizing flow bin 2 and then enter the roller press 3 for further grinding, and the fine powder collected by the double cyclone dust collector 7 is controlled by the first electric dividing valve 30 to enter the second weighing stabilizing flow bin 14, and then enters the ball mill 16 for further grinding after being measured by the rotor scale 15. The ground material is transported to the finished product warehouse through the fourth chute 17, the third elevator 18, the fifth chute 19, and the second chute 12, which is the mode 1 combined grinding process of the present invention, specifically the roller press + open-circuit cement tube mill combined grinding;

[0133] like Figure 6 and Figure 7 As shown, when the coarse powder collected by the three-separation high-efficiency powder classifier 6 is controlled by the distributing valve 27 to return to the first weighing steady flow bin 2 and then enter the roller press 3 for further grinding, a part of the medium coarse powder is controlled by the first gate valve 28 to return to the first weighing steady flow bin 2 and then enter the roller press 3 for further grinding, and a part of the medium coarse powder is controlled by the second gate valve 29 to enter the second weighing steady flow bin 14 and then enter the ball mill 16 for further grinding after being measured by the rotor scale 15. The material ground by the ball mill 16 passes through the fourth chute 17, the third elevator 18, and the fifth chute 19 to enter the T-sepax high-efficiency three-separation powder classifier 20 for powder selection, and the fine powder collected by the double cyclone dust collector 7 is directly controlled by the first electric distributing valve 30 on the first chute 11 to be transported to the second chute 12 to enter the finished product warehouse to make the finished product, which is the mode 2 semi-final grinding process of the present invention, specifically the roller press + closed-circuit tube mill semi-final grinding;

[0134] like Figure 8 and Fig. 9 As shown, when the coarse powder collected by the three-separation high-efficiency powder selector 6 is controlled by the distributing valve 27 to return to the first weighing stabilizing flow bin 2 and then enter the roller press 3 for further grinding, a part of the medium coarse powder is controlled by the first gate valve 28 to return to the first weighing stabilizing flow bin 2 and then enter the roller press 3 for further grinding, and a part of the medium coarse powder is controlled by the second gate valve 29 to enter the second weighing stabilizing flow bin 14 and then enter the ball mill 16 for further grinding after being measured by the rotor scale 15. The material ground by the ball mill 16 is transported to the finished product warehouse through the fourth chute 17, the third elevator 18, the fifth chute 19, and the second chute 12. The fine powder collected by the double cyclone dust collector 7 is directly controlled by the first electric distributing valve 30 on the first chute 11 to be transported to the second chute 12 to enter the finished product warehouse to make the finished product, which is the mode 2 semi-final grinding process of the present invention, specifically the roller press + open-circuit cement pipe mill semi-final grinding;

[0135] like Fig.10 and Fig.11 As shown, when the coarse powder and medium coarse powder collected by the three-separation high-efficiency powder selector 6 are all returned to the first weighing steady flow bin 2 through the control of the dividing valve 27 and the first gate valve 28, and the fine powder collected by the double cyclone dust collector 7 is directly controlled by the first electric dividing valve 30 on the first chute 11 and transported to the second chute 12 to enter the finished product warehouse to be made into finished products, the situation where the cement mill and ball mill grinding system are bypassed is the mode three final grinding process of the present invention.

[0136] In the mode 2 semi-final grinding process mode, when high-grade cement needs to be ground or the water requirement is high, the fine powder collected by the double cyclone dust collector 7 can also enter the ball mill 16 through the first electric feeder valve 30 for further grinding, and the ball mill 16 is used for particle shaping to meet the quality requirements.

[0137] When a device in the ball mill grinding system fails, the ball mill grinding system can be shut down by adjusting the directions of the dosing valve 27 and the first electric dosing valve 30 and closing one end of the second gate valve 29 connected to the ball mill 16 to facilitate the maintenance of the ball mill grinding system.

[0138] In this embodiment, the powder selection accuracy levels of the four powder selection machines, namely, the V-type powder selection machine 5, the three-separation high-efficiency powder selection machine 6, the double cyclone dust collector 7, and the T-sepax high-efficiency three-separation powder selection machine 20, are from low to high. However, it is not limited to using only these powder selection machines, and other types of powder selection machines can also be used as long as they can meet the required powder selection effect.

[0139] In this embodiment, the ball mill 16 may be a cement tube mill.

[0140] Example 2

[0141] This embodiment provides a composite multi-process cement grinding process, which uses the composite multi-process cement grinding system described in Example 1 for grinding, including three grinding processes, namely a combined grinding process, a semi-final grinding process, and a final grinding process.

[0142] The combined grinding process is: the coarse powder and medium coarse powder collected by the three-separation high-efficiency powder selector 6 are controlled to enter the roller press 3, and the fine powder collected by the double cyclone dust collector 7 is controlled to enter the ball mill 16 for further grinding;

[0143] The semi-final grinding process is as follows: the coarse powder collected by the three-separation high-efficiency powder classifier 6 is controlled to enter the roller press 3, and part of the medium-coarse powder collected by the three-separation high-efficiency powder classifier 6 is controlled to enter the roller press 3, and part of it enters the ball mill 16, and the fine powder collected by the double cyclone dust collector 7 is used as the finished product, and the fine powder is collected into the second chute 12 through the first chute 11 and transported to the finished product warehouse as the finished product;

[0144] The final grinding process is as follows: the coarse powder and medium coarse powder collected by the three-separation high-efficiency powder selector 6 are controlled to enter the roller press 3, and the fine powder collected by the double cyclone dust collector 7 is used as the finished product, and the fine powder is collected into the second chute 12 through the first chute 11 and transported to the finished product warehouse as the finished product;

[0145] For the combined grinding process and the semi-final grinding process, they include an open circuit process and a closed circuit process respectively;

[0146] The closed-circuit process is as follows: the materials ground by the ball mill 16 are controlled to enter the T-sepax high-efficiency three-separation powder separator 20 for sorting, and the qualified materials after sorting enter the finished product warehouse through the second chute 11;

[0147] The open circuit process is: controlling the material ground by the ball mill 16 to directly enter the finished product warehouse through the second chute 12.

[0148] Example 3

[0149] like Fig.12 As shown, this embodiment provides a cement production method, comprising the following steps:

[0150] S1. Two cement grinding systems described in Example 1 are arranged in a cement grinding workshop, namely cement grinding system 1 and cement grinding system 2. Each cement grinding system can switch to multiple modes. The two cement grinding systems are used to grind clinker and mixed materials separately.

[0151] S2. The ground clinker and mixed material are stored separately in storage 1 and storage 2 respectively.

[0152] S3. According to the different types of cement produced, the amount of clinker and mixed materials is controlled by a metering scale in the mixing system, and the two are sent together into the mixing system for mixing of cement types; the finished products are transported to the cement finished product warehouse system for separate storage.

[0153] In step S1, mode three final grinding mode is used to grind single materials separately, especially clinker which is difficult to grind. The particle size of clinker powder needs to be controlled during grinding. Mixed materials are ground separately and the particle size is controlled as needed.

[0154] The following is an example to further illustrate that the cement grinding system in WX Cement Plant is composed of two Φ3.8m×13m ball mills 16, two Φ1800×1600mm roller presses 3, two V-type powder selectors 5, two LSX5000 three-separation high-efficiency powder selectors 6 and two T-sepax high-efficiency three-separation powder selectors 20. It is a composite multi-process cement grinding production line composed of roller presses 3 and ball mills 16. The mixed material from the batching warehouse enters the first weighing steady flow bin 2 through the belt conveyor and the first elevator 1. The material out of the bin is squeezed by the CDG180160 roller press 3 and then enters the CDV6000 through the second elevator 4. After classification by the V-type powder classifier 5, the large coarse particles exiting the V-type powder classifier 5 are returned to the roller press 3 for further extrusion and grinding, while the other materials exiting the V-type powder classifier 5 are further sorted by the LSX5000 three-separation high-efficiency powder classifier 6, and the coarse powder is returned to the roller press for further grinding, while the medium-coarse powder can be returned to the roller press or can be entered into the ball mill for further grinding; among them, the roller press grinding system is separately equipped with an independent dust removal system, which can bypass the ball mill grinding system to achieve the final grinding method of the roller press. Since the two systems coexist, the clinker and mixed materials can be separately ground and stored by the two systems, and then synthesized into qualified cement varieties in the mixing system. Compared with the general cement grinding system, this engineering system has high output, low clinker material consumption, low power consumption, reasonable particle gradation of cement products, improved cement product quality, and higher market acceptance.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A composite multi-process cement grinding system, characterized by: It includes a roller press grinding system and a ball mill grinding system, wherein the roller press grinding system includes a first steady flow bin, a roller press, a primary powder classifier, a first fine powder classifier, a cyclone dust collector, and a first fan connected in sequence; the ball mill grinding system includes a ball mill, a second fine powder classifier, and a second chute; The primary powder classifier is used to perform primary classification of materials, the coarse powder outlet of the primary powder classifier is connected to the feed port of the first stabilizing bin, and the first outlet of the primary powder classifier is connected to the feed port of the first fine powder classifier; The coarse powder outlet of the first fine powder classifier is connected to the feed inlet of the first stabilizing bin and the ball mill grinding system, and a control valve is provided between the coarse powder outlet of the first fine powder classifier, the feed inlet of the first stabilizing bin and the ball mill grinding system; the medium coarse powder outlet of the first fine powder classifier is connected to the first stabilizing bin and the ball mill grinding system, and a control valve is provided between the medium coarse powder outlet of the first fine powder classifier, the first stabilizing bin and the ball mill grinding system; the air outlet of the first fine powder classifier is connected to the air inlet of the cyclone dust collector, and the discharge port of the cyclone dust collector is connected to the first chute; The first chute is connected to the second chute and the ball mill grinding system, the second chute is connected to the finished product warehouse, and the first chute is provided with a first regulating valve, the first regulating valve is used to regulate the first chute to control it to be connected to the second chute or the ball mill grinding system; The finished product outlet of the second fine powder classifier is connected to the second chute, and the ball mill is connected to the second fine powder classifier and the second chute through the fifth chute. The fifth chute is provided with a second regulating valve, and the second regulating valve is used to adjust the fifth chute to control it to be connected to the second fine powder classifier or the second chute.

2. The composite multi-process cement grinding system according to claim 1 is characterized in that: A dividing valve is provided between the coarse powder outlet of the first fine powder classifier and the first stabilizing bin, the feed end of the dividing valve is connected to the coarse powder outlet of the first fine powder classifier, and the discharge end of the dividing valve is connected to the feed port of the first stabilizing bin and the ball mill grinding system.

3. The composite multi-process cement grinding system according to claim 2 is characterized in that: The ball mill grinding system also includes a second flow stabilization bin and a rotor scale. The second flow stabilization bin, the rotor scale and the ball mill are connected in sequence. The discharge end of the material distribution valve is connected to the feed port of the rotor scale.

4. The composite multi-process cement grinding system according to claim 1 is characterized in that: A first control valve is provided between the medium-coarse powder outlet of the first fine powder classifier and the dividing valve, and a second control valve is provided between the medium-coarse powder outlet of the first fine powder classifier and the second stabilizing bin.

5. The composite multi-process cement grinding system according to claim 1 is characterized in that: A first elevator is provided between the roller press and the primary powder classifier, and the first elevator is used to lift and transport the material ground by the roller press to the primary powder classifier; The ball mill is connected to the fourth chute, and a second elevator is arranged between the fourth chute and the fifth chute, and the second elevator is used to lift and transport materials to the fifth chute.

6. The composite multi-process cement grinding system according to claim 1 is characterized in that: The finished product outlet of the second fine powder classifier is connected to the second chute through the sixth chute, and the second outlet of the second fine powder classifier is connected to the ball mill through the third chute.

7. The composite multi-process cement grinding system according to claim 1, characterized in that: The air outlet of the first fan is connected to the air inlet of the first-stage powder classifier and the air inlet of the first dust collector, the air outlet of the first dust collector is connected to the air inlet of the second fan, and the discharge port of the first dust collector is connected to the second chute through the seventh chute.

8. The composite multi-process cement grinding system according to claim 1, characterized in that: The outlet end of the ball mill is connected to the air inlet of the second dust collector, the air outlet of the second dust collector is connected to the air inlet of the third fan, the first discharge port of the second dust collector is connected to the second chute, and the second discharge port of the second dust collector is connected to the fourth chute; The second fine powder classifier is connected to the air inlet of the third dust collector, the air outlet of the third dust collector is connected to the air inlet of the fourth fan, and the discharge port of the third dust collector is connected to the finished product warehouse through the second chute.

9. A composite multi-process cement grinding process, characterized in that: Grinding using the composite multi-process cement grinding system described in any one of claims 1 to 8 includes three grinding processes, namely, a combined grinding process, a semi-final grinding process, and a final grinding process; The combined grinding process is: the coarse powder and medium coarse powder collected by the first fine powder classifier are controlled to enter the roller press, and the fine powder collected by the cyclone dust collector is controlled to enter the ball mill for further grinding; The semi-final grinding process is as follows: the coarse powder collected by the first fine powder classifier is controlled to enter the roller press, and part of the medium and coarse powder collected by the first fine powder classifier is controlled to enter the roller press and part of it to enter the ball mill, and the fine powder collected by the cyclone dust collector is used as the finished product, and the fine powder is collected into the second chute through the first chute and transported to the finished product warehouse as the finished product; The final grinding process is as follows: the coarse powder and medium coarse powder collected by the first fine powder classifier are controlled to enter the roller press, and the fine powder collected by the cyclone dust collector is used as the finished product, and the fine powder is collected into the second chute through the first chute and transported to the finished product warehouse as the finished product; For the combined grinding process and the semi-final grinding process, they include an open circuit process and a closed circuit process respectively; The closed-circuit process is: the materials ground by the ball mill are controlled to enter the second fine powder concentrator for sorting, and the qualified materials after sorting enter the finished product warehouse through the second chute; The open circuit process is to control the materials ground by the ball mill to directly enter the finished product warehouse through the second chute.

10. A cement production method, characterized in that: The following steps are involved: S1. Arrange two sets of composite multi-process cement grinding systems as described in any one of claims 1 to 8 in a cement grinding workshop, namely cement grinding system 1 and cement grinding system 2, each cement grinding system can switch to multiple modes, and use the two cement grinding systems to grind clinker and mixed materials separately; S2, the ground clinker and mixed materials are stored separately in storage 1 and storage 2 respectively; S3. According to the different types of cement produced, the amount of clinker and mixed materials is controlled by a metering scale in the mixing system, and the two are sent together into the mixing system for mixing of cement types; the finished products are transported to the cement finished product warehouse system for separate storage.

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