FREEMAN TECHNOLOGY

Process-relevant characterisation of the flow properties of surface treated cement

All Freeman Technology

1 Measuring the force and torque acting on a helical blade as it rotates through the powder sample, under controlled conditions, quantifies flow energy, the energy associated with moving a powder in a defined flow/stress regime

2 AE data indicate that surface treatment has successfully reduced the strength of inter-particulate forces improving the flow characteristics of the cement under aerated conditions

3 The high compressibility of Sample 2 makes it most likely to be influenced by storage under its own weight and to exhibit poor hopper discharge performance

4 Shear cell data indicate that surface coating has not impacted flow properties under relatively high stress as much as under different conditions

Improving the flowability of cement helps to reduce the risk of poor process performance, a critical issue for an industry targeting the very highest levels of efficiency. This article describes the use of dynamic flow testing to characterise the flow properties of Portland cements and to quantify the enhancement achieved by surface treatment.

1 Introduction

The scale, capital-intensity and environmental impact of the cement industry shape its requirements for exceptional reliability and enhanced sustainability. With modern kiln systems capable of throughputs as high as 15000 t of clinker per day and investment costs for a new cement line in the region of several hundred million euros [1] the efficiency of cement manufacturing lines is critical. Rigorous process optimisation, along with the highest levels of reliability, maximises return on investment. At this scale even minimal amounts of unplanned downtime can rapidly add-up to...