Pellet production process adopting microwave low-temperature carbon-free roasting

A production process and microwave generator technology, applied in the direction of improving process efficiency, etc., can solve the problems of uneven pellet roasting, flue gas pollutant emissions, and high roasting temperature, so as to reduce energy consumption and achieve zero carbon emissions , the effect of reducing the emission of flue gas pollutants

Active Publication Date: 2022-07-12
CENT SOUTH UNIV
View PDF7 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In view of the fact that the pellet production process in the prior art mainly uses carbon-based fuel combustion and heat conduction heating as the main roasting method, the roasting temperature is high, the energy consumption is large, the pellets are roasted unevenly, and some pellets are "over-burned" or "under-fired". "burning", as well as the problems of carbon emissions and flue gas pollutant emissions. The purpose of the present invention is to provide a microwave low-temperature carbon-free roasting iron ore oxidation pellet production process. The key to this process is to directly heat the pellets by using microwave The uniform heating of the pellets promotes the full consolidation of the pellets in the roasting section, improves the quality of the pellets, and reduces the roasting temperature. At the same time, the heating method of direct microwave heating replaces the carbon-based fuel combustion in the prior art The heat supply method realizes "zero carbon emission" in the pellet production process and greatly reduces NO x and SO 2 emissions

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Pellet production process adopting microwave low-temperature carbon-free roasting
  • Pellet production process adopting microwave low-temperature carbon-free roasting

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Aiming at the microwave low-temperature carbon-free roasting pellet technology proposed in the present invention, 98.8% magnetic and hematite mixed iron concentrate raw materials (magnetite:hematite=7:3) are used, and 1.2% bentonite is added to prepare acid pellets. In the process, the pellet thickness is 200mm, the pellet size is 8-13mm, the microwave frequency is 2450MHz, and the thermal system is blast drying at 350℃ for 2min, 500℃ for 4min, preheating at 800℃ for 6min, and preheating at 1050℃ for 10min. After preheating, the FeO content in the pellets was 2.2%, and the desulfurization rate of the pellets was 92.3%; the finished pellets were obtained under the thermal regime of roasting at 1180 °C for 8 min and cooling rate of 80 °C / min. Pellet indicators, carbon emissions during pellet production, NO x Emissions are shown in Table 1.

Embodiment 2

[0039] Aiming at the microwave-based low-temperature carbon-free roasting pellet technology proposed in the present invention, magnesium is prepared by using 91.2% magnetic and hematite mixed iron concentrate, adding 0.5% organic binder (CMC), 3.8% magnesite and 4.5% limestone. Mass flux pellets (basicity 0.4, MgO content 2.0). In the process, the pellet thickness is 200mm, the pellet size is 8-13mm, the microwave frequency is 915MHz, and the thermal system is 300°C blast drying for 3 minutes, 450°C exhaust drying for 5 minutes, 1000°C preheating for 8 minutes, and 1150°C preheating for 8 minutes. After preheating, the FeO content in the pellets was 1.8%, and the desulfurization rate of the pellets was 88.3%; the finished pellets were obtained under the thermal regime of roasting at 1250 °C for 10 min and cooling rate of 50 °C / min. Pellet indicators, carbon emissions during pellet production, NO x Emissions are shown in Table 1.

Embodiment 3

[0041] Aiming at the microwave low-temperature carbon-free roasting pellet technology proposed by the present invention, 96.3% vanadium-titanium magnetite is used, 1.6% bentonite and 2.1% magnesium oxide powder are added to prepare magnesia vanadium-titanium pellets (MgO content 2.0%). During the process, the pellet thickness is 100mm, the pellet size is 8-13mm, the microwave frequency is 2450MHz, the thermal system is blast drying at 250℃ for 3min, 400℃ for 5min, preheating at 1000℃ for 10min, and preheating at 1150℃ for 6min. After preheating, the FeO content in the pellets was 2.7%, and the desulfurization rate of the pellets was 89.5%; the finished pellets were obtained under the thermal regime of roasting at 1230 °C for 12 min and cooling rate of 50 °C / min. Pellet strength index, carbon emissions during pellet production, NO x Emissions are shown in Table 1.

[0042] Table 1 implements the pellet strength index produced by the process of the present invention

[0043] ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention discloses a pellet production process adopting microwave low-temperature carbon-free roasting, which comprises the following steps of: placing a pellet material on a movable trolley, and sequentially treating the pellet material through a forced air drying section, an air draft drying section, a preheating section I, a preheating section II, a roasting section, a cooling section I, a cooling section II and a cooling section III to obtain finished pellets, the main improvement is that the roasting section directly supplies heat through a microwave device. According to the technology, pellet materials are evenly heated in a microwave direct heating mode, sufficient solidification of the pellet materials in the roasting section is promoted, the pellet quality is improved, the roasting temperature is reduced, meanwhile, the heat supply mode of microwave direct heating replaces the heat supply mode of carbon-based fuel combustion in the prior art, zero emission of carbon in the pellet production process is achieved, and the production cost is reduced. And the emission of NOx and SO2 is greatly reduced.

Description

technical field [0001] The invention relates to a pellet production process, in particular to a pellet production process of microwave low-temperature carbon-free roasting, and belongs to the technical field of energy saving and emission reduction of iron ore pellets. Background technique [0002] Pellets are high-quality raw materials for blast furnace ironmaking. Compared with sintered ore, they have the advantages of high iron grade and good metallurgical properties, and the process energy consumption and pollutant emissions of the pellet production process are also lower. In addition, the status quo of iron ore resources dominated by concentrates in my country is also more suitable for the development of pellets. In recent years, with the development of the steel industry, the output of pellets has also shown a gradual upward trend. Therefore, promoting the progress and development of the pelletizing process and further developing the energy-saving and emission-reductio...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C22B1/20C22B1/243C22B1/244
CPCC22B1/20C22B1/243C22B1/244C22B1/2406Y02P10/20
Inventor 甘敏范晓慧吕浩季志云孙增青陈许玲黄晓贤刘卓奇
Owner CENT SOUTH UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap