Gradient combustion technology divides the furnace space of the calciner into functional partitions through multi-stage control of the air inlet, feeding, and coal injection, establishing a combustion atmosphere environment of "strong lean oxygen reduction zone - weak lean oxygen reduction zone - combustion zone", thereby achieving source emission reduction of NO_X. This article develops an online gradient combustion calciner and a supporting swirl dispersion burner, which can increase the residence time of the strong reduction zone to 2.5~3.0 seconds and improve the self denitrification effect. The application of this technology in the Tengzhou Dongguo production line shows that, the self denitrification efficiency can reach over 70%, the stable control of NOX at the outlet of the calciner is below 260mg/Nm³, and the NOX emission control of the chimney gas is 30~50mg/Nm³. the dosage of ammonia water used in the clinker production is less than 2.5kg/t, achieving low-cost and ultra-low emission of NO_X in cement kiln flue gas.

Based on the current situation and existing problems of intelligent construction in the cement industry's grinding system, combined with the achievements of intelligent grinding research, a new intelligent construction plan of "expert diagnosis+ intelligent control+ intelligent operation" is proposed. Taking the "roller press+ ball mill" joint grinding system as an example, the specific content and precautions for the implementation of the intelligent construction plan of the cement grinding system are introduced in detail. The application effect of the pilot enterprise shows that, the new intelligent construction plan can effectively enhance the intelligent level of the cement grinding system, improve the production economic indicators of the cement grinding system, and improve the stability of product quality.

This article introduces the cement equipment intelligent operation and maintenance platform independently developed by Tianjin Cement Institute from three aspects: service system, operation and maintenance strategy, and platform architecture. The cement equipment intelligent operation and maintenance platform is customer-oriented, and conducts full lifecycle testing of cement production and cement equipment. It provides cement production enterprises with digital and intelligent equipment operation and maintenance services, including intelligent early warning, fault diagnosis, optimization of production, data analysis, and expert services. By collecting real-time production and process design data, graphically displaying multi-dimensional production operation indicators, establishing a multi-application scenario data analysis model, conducting production operation and equipment health management, establishing a digital expert library to provide functional module knowledge basis, achieving intelligent operation and maintenance of cement equipment, improving the operation rate of cement production equipment, and promoting the digital transformation of cement production enterprises.

This paper analyzes the drawbacks and causes of the current modular project management platform for cement engineering, and innovatively proposes a smart engineering project management platform. The platform is based on project management data, led by project implementation planning, with time as the management axis, each sub project as the spatial positioning, business activity management as the core, and progress, quality, and cost management as the focus of performance evaluation. By constructing five modules of "database, project implementation planning, business management, performance management, and functional management", the platform has achieved intelligent guidance for various tasks and achieved interconnectivity of project management process data, improved the intelligence level of project management.

Due to factors such as early input of roller presses, small selection, the cement semi-final grinding system has problems such as high power consumption and low output. By combining the existing two small roller presses with one ball mill to form a "two drag one" double closed circuit semi- final grinding system, and adding a large roller press system, the energy efficiency utilization rate of the roller press has been improved, the operating pressure deviation has been improved, and the crushing capacity has been enhanced. At the same time, by changing the internal structure of the ball mill from two chambers to three chambers, using ceramic ball grinding bodies in the third chamber, replacing anti blocking ball mill partition plates and discharge grate plates, optimizing activation rings, etc., the cement particle grading has been optimized. The comprehensive power consumption of cement grinding has been stabilized at around 22kW·h/t, and the system output has been increased from 190t/h to 325~335t/h, providing an important technical approach for energy conservation and carbon reduction in cement production.

The SFC4×6 push rod cooling machine has problems such as high failure rate, poor extreme cooling effect, low heat recovery efficiency, and high power consumption. Therefore, the fourth generation walking beam with intermediate roller crusher grate cooler of Tianjin Cement Institute is adopted for replacement and transformation. The walking grate cooler with intermediate rollers adopts a fixed slope grate plate with the Coenda effect, and the horizontal movable grate bed is designed based on the walking principle. The grate bed rows are equipped with gas sealing devices and dust sealing devices, and there is no material leakage in the grate bed. The central roller crusher can crush red and large materials to a particle size of  below 25mm, with good secondary cooling effect. After the renovation, the clinker temperature of the cooler was stabilized below 100 ℃, the heat recovery efficiency of the cooler was increased from 54% to 78%, the secondary air temperature was stabilized between 1 150℃ and 1 200℃, the power generation was increased to 29~30kW·h/t, and the equipment operation rate was improved, achieving the expected renovation goals.

The cement plant burns 100% anthracite, the self-denitrification effect is poor, the initial emission concentration of NOx is high, the CO concentration at the outlet of the calciner is high, and the SNCR denitrification efficiency is low. By installing new ammonia injectors at different heights of the calciner, ammonia mist droplets are sprayed into the flue gas to accelerate the mixing of ammonia and NOx. And an intelligent control model is established to dynamically adjust the amount of ammonia injected in different temperature ranges of the pyro system to reduce the total amount of ammonia injection. It tests the denitrification effect of different layers of spray guns, and determines the inlet and outlet of C6 as the best spray points for denitrification of spray guns, etc. After the transformation, the high-efficiency SNCR denitrification efficiency of T cement plant can reach 75%. Compared with the denitrification efficiency of burning anthracite and bituminous coal, if the burning anthracite is adjusted to burning bituminous coal, the denitrification efficiency of T cement plant can be further improved.

The inlet duct and insulation design of AQC boiler in cement kiln waste heat power plant have a significant impact on boiler operation and heat utilization. To reduce heat loss and improve waste heat recovery efficiency, insulation measures need to be taken for the inlet duct. This article analyzes the heat transfer mechanism of the AQC boiler inlet duct, establishes a physical field model of the AQC boiler inlet duct, and conducts numerical simulation calculations using software of Fluent. The temperature field of the AQC boiler inlet duct with different inner insulation layer thickness and the linear relationship curve of the hot air temperature with the length of the duct are obtained. The numerical simulation results indicate that the most economical and reasonable design scheme for insulation layer thickness is when the thickness of the inner insulation layer of the inlet duct（?3 620mm×8mm）of the AQC boiler is 70mm, and the thickness of the wear-resistant casting material and outer insulation layer is 100mm.

During the operation of the ?4.2m×13m cement sliding shoe mill discharge end cylinder, there were abnormal situations such as spraying dust. Upon inspection, it was found that the cement sliding shoe discharge end cylinder was worn and perforated, and a large amount of dust entered the lubrication system of the sliding shoe from the perforation. After analyzing the reasons and comparing multiple plans, based on the actual production situation, a repair plan was selected to repair and strengthen the protective plate of the cylinder. After implementing this plan, the repair construction was completed within 3 days (24-hour operation). After the repair of the mill cylinder, the strength of the cylinder was strengthened, and the insulation and deformation prevention of the cylinder were achieved, achieving the expected repair effect.

Based on the operation data of ?4.8m×74m rotary kiln, it briefly descrbes the measuring method of the clearance between the kiln tyre and the backing plate by measuring the thermal expansion and slippage, and the impact of clearance size on the operation of rotary kiln and its adjustment measures. Excessive clearance between the kiln tyre and the backing plate would easily cause the breakage and fall-off of the refractory bricks and shorten its service life, while too small clearance would easily cause uneven thermal expansion of the rotary kiln and result in the "necking" phenomenon, which would seriously affect the safe operation of the kiln. By strengthening the lubrication and maintenance, adjusting the thickness of the backing plate, replacing the backing plate, etc., the clearance between the kiln tyre and the backing plate could be ensured within a reasonable range, which reduce costs of kiln maintenance, and further improve the operation rate of the rotary kiln.

The traditional bulk loading system of aggregate production lines has a low level of intelligence, and there are problems during the loading process, such as the need for drivers to cooperate with the truck, the tendency of bulk machines to jam and overflow materials, and the difficulty of quantitative loading. The quantitative automatic loading system based on mobile belt machines achieves the design goals of quantitative loading, automatic feeding, and intelligent operation of central control through buffer bin replenishment, weighing bin measurement and control, bidirectional reversible tape machine uniform loading, and precise loading capacity using car scales. This reduces the number of operators, reduces labor intensity, reduces operating costs, and improves loading efficiency.

After the introduction of new energy power generation technology in cement factories, how to reasonably set up electricity metering points and new energy power generation access points is related to the safety, stability, and economy of the cement factory's power system. This paper elaborates on the layout plan of the electrical energy metering and analysis system for a cement production line. Based on the layout of the electrical energy metering system, grid connection voltage level, and capacity requirements, the selection of access point schemes for three new energy generation methods, namely photovoltaic power generation, wind power generation, and waste heat power generation, is proposed. By reasonably planning the layout of the cement plant's electricity metering system and the access points for new energy generation, real-time and comprehensive collection of cement plant power system operation data can be achieved. It optimizies electricity management, and further achievies energy conservation and consumption reduction.

The Life Cycle Assessment (LCA) method was used to compare and study the environmental impact of the whole production process of P·O 42.5R cement and P·Ⅱ 42.5R cement produced before and after the use of mixed material in a cement plant in Guangzhou, and the evaluation results were analyzed. Six environmental impact types were selected: Global Warming Potential(GWP), Acidification Potential(AP), Abiotic Depletion Potential(ADP), Eutrophication Potential(EP), Respirable Inorganic material(RI), and Photochemical Ozone Formation Potential(POFP). LCA calculation shows that adding 3.34% gangue and 3.32% fly ash in the cement grinding process can reduce the six environmental impacts of the cement production process. GWP, ADP, AP, EP, RI and POFP decreased by 8.52%, 9.18%, 9.09%, 8.68%, 8.88% and 8.29% respectively.