Eco-cement refers to the cement with good ecological environment coordination made by using various wastes such as papermaking sludge and their incinerators as the main raw materials through certain production processes. With the strong support of Zhengzhou Hengda Papermaking Equipment Co., Ltd., the project was launched in March 2021 in the College of Civil Engineering of Henan Polytechnic University, and a series of tests were carried out.
The chemical composition and mineral composition of sludge were analyzed by X-ray diffraction ( XRD ) and X-ray fluorescence diffraction ( XRF ). The results show that the calcined papermaking sludge ash has certain activity or potential activity due to the existence of CaO and active SiO2, Al2O3 components produced by high-temperature decomposition such as CaCO3. The experimental study found that when the heating rate and other process conditions remained unchanged, the activity of sludge ash was the highest when the equal mass of papermaking sludge ash calcined at 650 °C replaced 10 % of cement. When the content of calcined sludge ash was 15 % at 650 °C, the compressive strength was the highest, and the 7 d compressive strength was 14.5 % higher than that of pure cement. Subsequently, a series of experiments will be carried out to complete the resource utilization of papermaking sludge, and cooperate with Zhengzhou Hengda Papermaking Equipment Co., Ltd.
Determination of setting time of mortar Calcination of muffle furnace
Calcination results at different temperatures
Heating mode diagram
