Co-processing in cement kilns is an important approach for the harmless treatment and resource utilization of municipal sludge; however, odor pollution has become a key factor restricting the large-scale promotion of this technology. Based on the characteristics of cement production processes, this paper systematically analyzes the odor generation stages and pollutant characteristics throughout the entire process of co-processing municipal sludge in cement kilns. It examines the core components, emission patterns, and influencing factors of drying odors, with a focus on sludge drying technologies adapted to cement kiln operating conditions. The study elucidates the odor release characteristics of various drying processes, including disc, thin-layer, fluidized bed, biological, low-temperature belt, and swirl-classification drying, and proposes targeted odor control measures such as chemical conditioning, incineration, activated carbon adsorption, and biofiltration. The feasibility of these technologies is verified through engineering applications, demonstrating that the high temperature of 1 400℃ in cement kilns can effectively decompose drying odors, while biological drying can achieve odor control through enhanced aeration and two-stage biofiltration. The findings provide technical references for the cement industry to carry out municipal sludge co-processing and address odor pollution challenges, and also lay a foundation for subsequent process coupling innovations to achieve odor emission reduction throughout the entire co-processing of municipal sludge in cement kilns.

To address the cost pressures on clinker production caused by rising coal prices, a cement company experimented with using coal slurry (with a calorific value of approximately 2 000kcal/kg) as an alternative fuel. The slurry was blended into the cement raw meal at a ratio of 1.98%, ground, and then fed into the kiln for clinker burning. This paper presents a comparative analysis of changes in rotary kiln system operating parameters, clinker quality, coal consumption, SO₂ emissions, and economic benefits before and after the addition of coal slurry, based on industrial trials. The results indicate that after adding coal slurry, the system’s standard coal consumption decreased by 3.89kg/t.cl, fuel costs per ton of cement clinker fell by 3.93CNY, the 3-day compressive strength of clinker increased by 1.32MPa, and waste heat power generation increased by 1.12kW·h/t.cl, with comprehensive annual cost savings reaching 5.1 million CNY; however, SO₂ emission concentrations rose during mill shutdowns, requiring the auxiliary use of desulfurization agents. This study provides practical reference for the resource utilization of coal slurry and for cement enterprises to reduce costs and improve efficiency.

 With the implementation of ultra-low emission standards in the cement industry, the application of limestone-gypsum wet desulfurization technology has become increasingly widespread. However, as the wet desulfurization system operates over time, problems such as declining desulfurization efficiency and difficulty in dewatering gypsum have gradually emerged. Based on the actual operation of a cement plant's limestone-gypsum wet desulfurization system, this paper analyzes the main reasons for the reduction of desulfurization efficiency, including improper control of pH value and density of absorption tower slurry, low liquid level in absorption tower, and blocked oxidation air pipes. By taking refined treatment measures such as accurately controlling the pH value of the absorption tower slurry to 5.2~5.8, reasonably controlling the slurry density to about 1 080kg/m³, strengthening the maintenance and verification of liquid level gauges, regularly cleaning the oxidation air pipes, and standardizing the operation of the oxidation fan, these measures effectively guarantee the stable and efficient operation of the desulfurization system.

 The cement silo discharge system is critical equipment in cement production, and its stable operation directly affects the continuity of cement production and product quality. Traditional discharge systems generally suffer from the "funnel flow" phenomenon, in which materials only flow along the central area while materials near the silo wall remain static for a long time, resulting in material caking, arching, blockage and other problems. Based on the strategy of "flow field reconstruction + intelligent control", the Powder Flow Control technology realizes the mass flow discharge of materials. Taking a single cement silo of a company as an example, this paper proposes a technical renovation scheme adopting the Powder Flow Control V7.0 H-type control system. By installing Taiji cones and rectifying grids inside the silo, equipping pneumatic flow valves at the silo bottom, and integrating a local/remote dual-mode intelligent control system, the mass flow discharge at the bottom of the cement silo is realized. After renovation, the thickness of the caked material layer in the cement silo decreases significantly, the arching problem is completely eliminated, the power consumption per ton of cement is reduced by 0.74kW·h/t, the silo utilization rate is increased to 98%, and the annual direct economic benefit reaches 2.32×10⁵CNY. This provides a reliable scheme for the upgrading of cement silo discharge systems.

 In the cement production process, the iron removal effect of the raw meal roller grinding system directly affects the stability of equipment operation and product quality. A certain company used a disc magnetic separator and a permanemt magnetic drum at two separate locations for iron removal, which had problems such as severe dust emission, low iron removal efficiency, high labor intensity, high maintenance costs, and frequent shutdowns of the mill. Therefore, a transformation was implemented based on the cement raw material batching process and the source of iron impurities. A disc-type electromagnetic separator to remove iron at the source was added above each raw material conveying belt conveyor to intercept iron at the source; the original external discharge belt conveyor was removed, and the discharge process was simplified; the discharge belt conveyor was fully sealed and a scraper chain cleaning device to eliminate dust and material backflow; iron removal equipment was added at the discharge area of the mill cleaner, the circulating elevator discharge chute, and the discharge port of the feed belt conveyor to form multiple levels of protection. After the transformation, the dust emission at the site was effectively controlled, the iron removal efficiency was significantly improved, unplanned shutdowns due to iron blockage were completely eliminated, labor intensity and maintenance costs were significantly reduced, and the stability of the mill operation was significantly improved.

 As an important admixture for cement production, the discharge stability and weighing accuracy at the bottom of fly ash silos directly affect the output and quality of the cement grinding system. At present, cement plants generally adopt discharge and weighing configurations such as "single-tube screw feeder + weigh belt feeder" or "single-tube screw feeder + single-tube screw weighing scale", which often suffer from the problems such as material rushing and low weighing accuracy. Although the rotor scale has become the preferred weighing equipment due to its high precision and high stability, it still faces difficulties such as easy material rushing and dust collector failure in practical application. Based on two actual engineering projects, this paper systematically analyzes the problems existing in the bottom discharge system of fly ash silos and the rotor scale weighing system, and puts forward optimization schemes including canceling redundant aeration systems, adding variable-pitch screw feeders, and increasing the capacity of intermediate bins. The reforming practice shows that the optimized rotor scale weighing system has completely solved the problems of material rushing and uneven material flow at the bottom of fly ash silos, significantly improved the weighing accuracy, and ensured the stable and efficient operation of the cement grinding system.

With the gradual depletion of bauxite resources in China, the significance of the sintering method in alumina production is increasingly prominent. As the critical equipment in the alumina clinker calcination system, the cooling device directly affects the energy consumption index and product quality of the system. This article takes the walking steady-flow grate cooler in the cement industry as the research object and systematically analyzes its adaptive transformation and optimization upgrade in the cross-industry alumina clinker sintering process. By comparing the traditional single-tube and double-tube cooling devices in alumina production and analyzing the physicochemical properties of alumina clinker, the improvement measures of the cooling equipment are expounded, revealing the technical path of the cross-industry application of the walking steady-flow grate cooler. The research shows that in response to the high alkalinity, strong corrosivity, and easy deliquescence of alumina clinker, through the development of special corrosion-resistant and wear-resistant materials, optimization of the grate cooler's grate plate structure, and addition of a screening device, the technical problems such as easy clogging and rapid wear of the walking steady-flow grate cooler in the alumina clinker cooling process can be effectively solved, meeting the requirements of the alumina clinker cooling process and providing a useful reference for the cross-industry application of cement industry cooling equipment in the nonferrous industry.

A 4 500t/d cement clinker production line faced issues such as low preheater heat exchange efficiency, high negative pressure and temperature at the outlet of the C1 cyclone, small decomposition furnace volume, insufficient cooling capacity of the grate cooler, and high standard coal consumption for clinker pyro system. By implementing measures including upgrading the five-stage preheater to a six-stage one, expanding the decomposition furnace, reducing resistance in each cyclone, replacing the reciprocating push-type grate cooler with a stepped high-efficiency grate cooler, and replacing the kiln head burner, the system's operational stability was significantly improved. After transformation, the system's standard coal consumption decreased by 14.23kg/t.cl, the outlet temperature of the C1 cyclone dropped from 305℃ to 295℃, the outlet negative pressure decreased by 200Pa, the electricity consumption of the pyro process decreased by 5.99kW·h/t.cl, and the 3d and 28d compressive strength of the clinker increased by 6.1MPa and 5.5MPa respectively. Annually, it can save 27.1696 million CNY and reduce CO₂ emissions by approximately 54 421t, demonstrating good economic and social benefits.

In response to the typical faults in the hydraulic system of a roller press caused by high dust levels and harsh working conditions, such as oil contamination, system overheating, and main cylinder oil leakage, a systematic analysis of the fault causes was conducted, and optimization measures were proposed. By adding a return oil filter and a circulating filtration cooling system, along with a design that separates the oil tank cleaning side from the return oil side, the oil cleanliness and system thermal stability were effectively improved. Additionally, through structural modifications to the main cylinder — such as adopting stepped plungers, increasing the return oil port in the oil drainage chamber, and incorporating axial main seals with a double-layer seal structure — the sealing reliability of the main cylinder was enhanced. Practical application demonstrated that after the hydraulic system improvements, the frequency of faults like valve jamming, component wear, and pressure retention failure significantly decreased. The service life of the main cylinder seals was extended from approximately 2 years to 3~5 years, effectively improving the stability and reliability of the roller press's hydraulic system while reducing equipment failure rates and maintenance costs.

To clarify the contact shear performance between stored cement and multi-compartment silos made of different materials, this paper systematically conducted direct shear tests on the contact interfaces between cement and Plexiglas, polypropylene (PP) board, and cement mortar. The test results indicate that the shear stress at the contact interface of each material increases continuously with the increase in shear displacement, and a higher vertical stress corresponds to a higher maximum shear stress value. By fitting the Mohr-Coulomb strength criterion, the internal friction angle of cement was calculated to be 34.2°. The friction coefficients of the contact interfaces between cement and Plexiglas, PP board, and cement mortar were determined to be 0.51, 0.54, and 0.74, respectively. On this basis, by introducing the material friction coefficients and geometric dimension parameters, a conversion formula for lateral wall pressure between a combined Plexiglas-PP board mortar silo and a single-material cement mortar silo was derived.  This provides an effective approach for the mutual conversion of lateral wall pressure among silos made of different materials, offering robust theoretical support for conducting lateral wall pressure tests on multi-compartment cement silos and for the practical application of test results in engineering projects.

To address the issues of low efficiency and inability to meet the demands of modern mining production associated with traditional ore particle size detection methods, this paper introduces a machine vision recognition-based image analysis methodology for ore size distribution characterization. The acquired images are first denoised using median filtering, which effectively suppresses noise while preserving particle edge sharpness. Subsequently, adaptive threshold segmentation is employed to separate ore particles from the background, and morphological operations are applied to eliminate adhesions and fill internal voids. Building upon this preprocessing, gradient-based segmentation coupled with distance transformation is utilized to delineate boundaries of touching particles. Finally, particle size distribution is quantified by fitting a calibrated “size-volume” model, enabling accurate particle identification and granularity analysis. Experimental validation from a sand and gravel aggregate production line project demonstrates that the ore particle size image detection system built using this method can reliably perform real-time particle size detection. Compared to manual sieving results, the error in the longest dimension of ore particles is controlled within 8%, and the P80 error is controlled within 14%. The detection accuracy meets the requirements for industrial field applications, providing effective data support for evaluating ore processing performance and optimizing production processes.

To explore the reasons for the unstable results of the determination of limestone content in cement by the alkali asbestos absorption weighting method, this paper experimentally tested the effects of factors such as limestone grade, weighing method of the U-tube in the absorption device, quality of the alkali asbestos absorbent, micro-boiling time of the reaction solution, and gas flow rate on the determination results. The experiments showed that the lower the limestone grade, the greater the negative deviation of the determination results; the stability of the weighing method where the U-tube of the absorption device is placed vertically in the beaker is better than that of the direct horizontal placement; the performance difference of the alkali asbestos absorbent directly affects the accuracy of the determination results; a micro-boiling time of the reaction solution < 4min would lead to a significant underestimation of the detection results; there is an optimal range for the gas flow rate (3~5 bubbles per second), and rates that are too fast or too slow would introduce errors in the determination results due to incomplete absorption of CO₂ gas or changes in system pressure. Finally, it is proposed that strictly controlling the quality of the experimental samples, standardizing the operation steps, and using alkali asbestos absorbents with stable performance are the keys to improving the accuracy of the determination results.

To meet the market demand for Portland cement in nuclear power projects and address the challenge of producing high-quality clinker from high-silica, low-calcium limestone, this study employed optimized raw materials and fuels, four-component raw meal blending, and refined calcination control techniques to produce nuclear-grade cement clinker with a silica ratio of approximately 3.50 and an alkali content below 0.40%. The resulting P·N42.5 cement exhibits the "three lows and one high" characteristics (low alkali, low heat of hydration, low dry shrinkage, and high early strength), not only meeting national standards but also providing a new pathway for the high-value utilization of low-grade limestone.

Aiming at the problems of material interruption and unstable material supply in the batching station caused by material blocking, silo bridging, empty silo, feeding scale failure and other issues in cement grinding production, which further lead to fluctuations in the working conditions of the grinding system, fluctuations in the quality of cement out of the mill, and an increase in system energy consumption, an automatic material interruption complementary control system based on an advanced control platform was developed. The system integrates two control modes: automatic and manual. In the automatic mode, according to the preset quality management parameters, material compensation is automatically triggered when material interruption or abnormal material supply occurs; in the manual mode, the operator sets parameters to participate in the compensation. The application results show that the system can accurately identify material interruption and material supply deviation in the batching station, effectively improve the stability of the working conditions of the grinding system and the quality stability of cement out of the mill, reduce system energy consumption, and at the same time reduce the workload of quality management personnel and operators, providing a solution for the stability control of similar grinding systems.

Traditional equipment management in cement plants is dominated by manual operation, which leads to delayed monitoring of equipment operating status, maintenance strategies lacking data basis, and severe information silos between systems. Targeting the above problems, this paper proposes an intelligent transformation solution for equipment management covering the entire production process. This solution adopts a hierarchical distributed architecture, integrating key technologies such as data acquisition and integration, data storage and management, and intelligent analysis and decision-making. It establishes functional modules including comprehensive equipment monitoring, predictive maintenance, smart energy management, full lifecycle management, intelligent decision support, and performance analysis. Engineering practice of a cement enterprise in Yibin proves that after the implementation of the solution, unplanned equipment downtime is reduced by more than 50%, overall efficiency increased by 15%, and maintenance costs decreased by 25%, which effectively improves equipment management capacity and operational benefits. This paper also analyzes technical, financial, talent and organizational challenges in the intelligent transformation of equipment management, and presents the future development trend of in-depth integration of digital twin and artificial intelligence, so as to provide a reference for the intelligent construction of equipment management in the cement industry.

To address the problems of high failure rates, reliance on manual experience for diagnosis, and long downtime in traditional lubrication systems for main bearings of mining mills, this study conducted a system failure mechanism analysis, constructed a lubrication system expert knowledge base including a rule base and a case base, and developed a fault diagnosis expert system based on a combination of CBR (case-based reasoning) and RBR (rule-based reasoning). This formed the core technical support for an intelligent lubrication system for mill main bearings. The system monitors lubrication system operating parameters in real time through sensors, enabling fault early warning, rapid matching, and in-depth diagnosis, and outputs targeted solutions. Simultaneously, it wirelessly transmits equipment status information to a cloud-based mining equipment industrial internet platform, supporting intelligent services such as remote monitoring, fault diagnosis, and preventive maintenance. Engineering applications show that this system effectively improves the operational reliability and intelligence level of the mill main bearing lubrication system, shortens downtime, reduces maintenance costs, and provides technical support for the intelligent and unmanned development of mining equipment.