LIU Zheng-jian
,
REN Shan
,
ZHANG Jian-liang
,
LIU Wei-jian
,
XING Xiang-dong
,
SU Bu-xin
钢铁研究学报(英文版)
In order to effectively recycle resource for the benefit of the global environment, the utilization of waste plastics as auxiliary injectant for blast furnaces is becoming increasingly important. Combustion kinetics of plastics-coal blends with 0, 10%, 20% and 40% waste plastics (WP) are investigated separately by thermogravimetric analysis (TGA) from ambient temperature to 900 ℃ in air atmosphere. These blends are combusted at the heating rates of 5, 10 and 20 ℃/min. The results indicate that, with the increase of waste plastics content, the combustion processes of blends could be divided into one stage, two stages and three stages. The waste plastics content and heating rates have important effects on the main combustion processes of blends. With the increase of waste plastics content, the ignition temperature and the final combustion temperature of blends tend to decrease, while the combustion reaction becomes fiercer. With the increase of the heating rate, the ignition temperature, the mass loss rate of the peaks and the final combustion temperature of blends combustion tend to increase. The Flynn-Wall-Ozawa (FWO) iso-conversional method is used for the kinetic analysis of the main combustion process. The results indicate that, when the waste plastics content varied from 0 to 40%, the values of activation energy increase from 126.05 to 184.12 kJ /mol.
关键词:
waste plastics
,
anthracite
,
co-combustion kinetics
,
TGA
,
iso-conversional method
LIN Yin-he
,
GUO Zhan-cheng
,
TANG Hui-qing
,
REN Shan
,
LI Jing-wei
钢铁研究学报(英文版)
Micro-fluidized bed reactor is a new research method for the reduction of iron ore fines. The reactor is operated as a differential reactor to ensure a constant gas concentration and temperature within the reactor volume. In order to understand the dynamic process of the reduction reaction in micro-fluidized bed, a series of kinetic experiments were designed. In the micro-fluidized bed, the use of shrinking core model describes the dynamic behavior of reduction of iron ore. And the apparent activation energy is calculated in the range of 700-850 ℃ while the initial atmosphere is 100% content of CO.
关键词:
iron ore reduction
,
micro-fluidized bed
,
dynamics
ZHANG Jian-liang
,
REN Shan
,
SU Bu-xin
,
LIN Yin-he
,
LONG Shi-gang
钢铁研究学报(英文版)
In order to study the combustion characteristics of waste tire particle (WTP), pulverized coal (PC) and their mixture, the contents of CO, CO2 and O2 of off-gas during the combustion of WTP, PC and mixture under the condition of rich oxygen by 0-4% in blast and at 1250 ℃ were measured simultaneously using synthetically infrared analyzer, and then the corresponding combustion ratio was calculated and compared. The results showed that the burning rate of WTP reached approximately 57%, which is much higher than that of PC (only about 18%) in the initial 650 s in fresh air, and then the increase of combustion rate of PC is faster than that of WTP; the combustion rate of PC improved remarkably with the addition of WTP. Meanwhile, the combustion rates of all these materials improved with the increase of oxygen content.
关键词:
blast furnace
,
waste tire particle
,
pulverized coal
,
combustion ratio
