The research progress of flue gas mercury removal technology at home and abroad, such as condensation, adsorption, oxidative absorption and synergistic mercury removal, are introduced. In recent years, with the rapid development of China's economy, mercury emissions have increased year by year, among which mercury emissions from the cement industry accounted for 14.3% of the total emissions. In order to protect the environment, mercury have been included in the cement industry to limit emissions of pollutants. It is of great significance to strengthen the research on technologies and equipment for mercury emissions in the cement industry.

The Paris Agreement established the basic framework for the international community to co-operate to address climate change after 2020, and countries all over the world are actively working on this. In Chinese 14th five-year plans and the 2035 long-term goal outline, ecological priority and green development is the development direction. This article focuses on green mine construction, material bed powder research technology, particle fluid theory, waste disposal and co-processing, establishment of a new low-carbon cement industrial system, powder modification and cement functionalization, and intelligent production and management to introduce the current scientific and technological achievements of chinese cement industry, combined with the analysis of the status quo of foreign industrial technology development, and put forward the ideas and tasks of implementing ecological priority and green development.

After analysis and comparison, the ratio of precalcining kiln refractory bricks is out of adjustment, which is mainly affected by the change of kiln diameter and the thermal mechanical stress and deformation of the cylinder, as well as the size of refractory bricks, brick shape accuracy, brick shape and other factors. By adopting C-type refractory bricks, improving the dimensional accuracy of bricks, and using refractory bricks with the opposite deviation direction when laying bricks, it can alleviate the problem of imbalance in the ratio of refractory bricks.

The specific surface area, grindability and activity index of fly ash in different regions of China are researched and analyzed. The results show that the activity index of fly ash varies greatly in different regions, and the improvement of fly ash activity index through physical activation is limited. It is uneconomical to increase the strength of cement concrete by only increasing the fineness of fly ash.

According to the performance requirements of C60 concrete, C60 concrete is prepared by using the method of single mixing of ultrafine grinding fly ash (>600m2/kg) or double mixing with S95 granulated blast furnace slag. Through experiments, a suitable mix ratio scheme for C60 concrete production is found. The C60 concrete produced is economical and can meet the requirements of concrete application.

In a 3 000t/d cement production line in Xingtai City, Hebei Province, through the modification of the calciner system and the optimization of the SNCR system, the calciner volume was expanded by 60%, the ammonia utilization rate was increased, and the flue gas NOx emission concentration was lower than 50mg/Nm³. The emission indicators meet the regional environmental protection emission requirements, and the modification effect is significant.

Aiming at the problem of poor grindability of a company's mixed materials and high power consumption of the open circuit cement mill combined grinding system, technical measures were taken to increase the ball diameter of the first chamber, increase the grinding area of the second chamber and the third chamber of the ball mill, and replace the self-cleaning grate plate of the replaceable screen plate. The cement output of P·O42.5 increased from 98t/h to 127t/h,  and the power consumption of the system decreased from 33.0kW·h/t to 28.3kW·h/t. The effect of increasing production and saving electricity was remarkable.

The situation of the raw meal grinding system being changed from the original roller grinding system to the final grinding system of the roller press is introduced. The new grinding system is equipped with a sealed feeder in front of the V-type powder separator, and a high-efficiency energy-saving fan is selected. The cyclone for collecting the finished product is changed to two, and the pneumatic gate valve is changed to a pneumatic rod valve, which uses permanent magnets motor for driving. After the transformation, the output of the raw meal grinding system was increased from 430t/h to more than 500t/h, and the power consumption of the system was reduced from 15.7kW·h/t to 10.8kW·h/t.

The reasons for the low fineness passing rate and high power consumption of CLM1700 coal mill are analyzed, and the problems such as high differential pressure of coal mill dust collector and high system resistance are rebuilt. Through technical measures such as increasing the dust collector pulse valve, increasing the area of the air outlet pipe of the separator and the area of the air inlet of the cyclone, the differential pressure of the dust collector is reduced from 4 500Pa to 1 300Pa, the passing rate of coal powder fineness is greatly improved, and the process electricity consumption is reduced from 33kW·h/t to less than 24kW·h/t, which receive a good improvement effect.

The application of JX-300XP automatic control system in a 2 500 t/d cement production line is introduced. JX-300XP automatic control system has the advantages of stable control, convenient operation and friendly interface. It realizes the functions of data acquisition, control operation, alarm monitoring, remote communication, real-time data processing and the functions of configuration, debugging and diagnosis of the information, and realizes the unification of process control and equipment management.

A design method of rotary feeder for cleaning rotor groove by mechanical method is introduced. By establishing mathematical model of rotor groove and compiling function calculation program, a self-cleaning rotary feeder with easy manufacture and good cleaning effect can be quickly designed.

The coal mill slag discharge used to be cleaned regularly by manual trolley, the labor intensity and workload of the field personnel handling was large. Through the transformation, it increased slag discharge belt and bucket elevator, and realized automatic chain program control. After that, the labor intensity of the post workers is greatly reduced, the normal operation of the production is ensured, and the use effect is good.

It describes the breakdown of the bolt group of the reducer shell and the bolt group of the torque supporting device caused by the foreign body stuck on the roller surface during operation of the roller press, and makes the fault mechanics analysis and comparison, finds out the main failure cause. And it introduces the roller press driving output and input shaft technical requirements and roller press input shaft online welding repair, processing of fault disposal method, summarizes the matters needing attention to avoid the occurrence of failure and ensure the safe and stable operation.

The chemical composition of wet slag with low content of R2O is close to that of clay, it is suitable for raw meal of the clinker. The experiment of wet slag proportioning in laboratory was carried out, and raw meal cost were calculated. The industrial test in the 6 500t/d cement was carried out by three steps. Additionally, the influence of proportioning scheme on raw meal cost and the influence of wet slag content on kiln system and clinker quality were studied. Results show that the ratio of clay to wet slag of 2:1 is the optimal scheme. The 28d compressive strength of clinker can be greatly increased and the cost of P·O42.5 cement can be reduced by 19.2 million yuan.

The lithofacies of the cement samples after the clinker strength decreased were contrastive analyzed.The existing problems of the clinker production were found out, and the improvement schemes were put forward. After adjusting the ingredients, controlling the fineness of raw materials, increasing the sintering temperature, and reducing the feeding quantity fluctuation, the strength of clinker in cement production was stabilized at 57MPa for 28d, and the mixing material content increased to 15%.

It analyzed the difference of solid-air ratio in pulverized coal pneumatic conveying between A and B weighing - pneumatic conveying technology and its influence on coal consumption and power consumption of cement sintering system. The results show that under the promise of low wear, low maintenance and high operation rate of weighing equipment, for a 5 000t/d clinker production line, A style pulverized coal weighing feeder can save 797t coal and 79 200 kW·h power each year due to its high solid-air ratio of pneumatic conveying.

This paper introduces the working process of cement rotary kiln waste heat power station isolated network operation, and makes in-depth analysis from personnel preparation, power load accounting, key operation steps, safety measures and other aspects. The successful implementation of isolated network operation has maintained the stability of kiln thermal system, reduced the consumption of refractory materials and reduced the production cost.

Introduced the composition of the optimized control system, and compared effect of drum water level, hot well water level, main feed water pressure after applying application optimization control. The waste heat power station is running more stable after applying optimization control. It makes workers reduce labor intensity and improve the automation control level of waste heat power station. Also it lay the foundation for few people on duty or quasi-unattended in waste heat power station.

This paper analyzes the reasons for the longer setting time of concrete in a concrete mixing station from the aspects of cement quality, concrete materials and mix ratio, and finally finds out that the longer setting time is caused by the alcohol pollution of concrete sand. After taking corresponding measures, the setting time returns to normal.