The suggestion to adjust and control the quality of cement clinker has been provided in this paper, in order to deal with the trouble of powdery clinker during the cement production in Tongling Conch 12 000t/d line. Based on the chemical analysis of raw meal and clinker, as well as the petrographic configuration of clinker, the main reasons of powdery clinker appearance, such as operation, fineness of raw meal, clinker modulus, mineral composition and etc., have been presented.

Stability of gypsum whisker at the different solutions was studied. By measuring compression strength, rupture strength, impact work, hydration heat, and through the tests of mercury injection, X-ray diffraction, and scanning electron microscopy, the effect of gypsum whisker on the mechanical properties, pore structure, and hydration heat of hardened fly-ash cement paste have been analyzed. Results show that gypsum whisker could improve strength of fly ash cement composite material, especially early strength, and the big pores got smaller, but the total porosity and density increased. The hydration heat of fly-ash cement could be reduced by adding appropriate gypsum whisker.

The effect on mechanical properties and microstructure of dry-mixed mortar and cement colloidal mortar caused by different proportions of waste concrete has been investigated. Experimental results show that mechanical properties (3d and 28d) of dry-mixed mortar and cement colloidal mortar increase firstly and then decrease with the increase of the proportions of waste concrete. The appropriate proportion is 40% considering the compression strength and workability.

According to the newly issued “Emission standard of air pollutants for cement industry (GB 4915-2013)”, the emission concentration values of dust collectors for cement kiln and grinding system have been restricted to less than 20mg/Nm³ in important protection areas. However, the designed value of existed bag filter reformed from ESP is 30mg/Nm³. How to meet the increasingly stringent environmental regulations according to the second modification of existed bag filters reformed from ESP with least investment is the key issue for cement plants. Based on the filter mechanism, the optimized method to decrease the emissions is to increase the filter area and reduce the filtration velocity. The aim can be realized in practice by means of CFD simulations and adding new bag compartments.