Development and application research of environmental-friendly coal antifreeze

Chlorine is one of the most harmful elements in coal. In the combustion process,it is mainly converted into HCl to corrode equipment and acidify air,endangering the health of animals and plants. Due to its high chlorine content(64%),traditional calcium chloride antifreeze will lead to a double or even ten of times increase in chlorine content in coal. The introduction of a large amount of chlorine makes the coal more harmful in subsequent applications,and exceeds the restrictions on coal chlorine content of exports. In order to promote the clean utilization of the whole process of coal,in this paper,a non-chlorine organic and inorganic composite pour point depressant and a metal composite corrosion inhibitor are added to develop an environmentally friendly coal antifreeze with excellent antifreeze performance and high corrosion inhibition. Its freezing point can reach -53 ℃,and the corrosion inhibition performance is excellent. The corrosion rates of steel,aluminum and copper are 0.03 mm/a,0.04 mm/a and 0.03 mm/a respectively,and the chlorine content is extremely low,only 86 ×10-6. According to the analysis of organic elements,the environment-friendly antifreeze coal contained mainly organic elements C,H,O three elements,which total content of 74.83%. It can be fully burned during the use of coal,reducing the impact of antifreeze on the subsequent use of coal. The antifreeze and the traditional calcium chloride antifreeze are compared in an industrial test. The results show that the spraying of calcium chloride antifreeze increase the chlorine content of the three groups of trains by an average of about 10 times，while the spraying of environmentally friendly coal antifreeze has almost no effect on the chlorine content in coal. The change of chlorine content is within the reproducibility criticality range specified by the test method. Other properties such as antifreeze of environmentally friendly coal antifreeze are also superior to calcium chloride antifreeze,which meets the antifreeze use of railway coal transportation and provides a new way for the low chlorine clean utilization of coal.