A method for direct reduction of industrial waste slag in rotary hearth furnace

A technology for industrial waste residue and rotary hearth furnace, which is applied in the direction of improving process efficiency, can solve problems such as difficulty, easy bursting and reduction of pellets, low falling strength of green pellets, etc., and achieves low production cost, low investment in equipment and infrastructure, and environmental protection. Effective measures

Inactive Publication Date: 2011-12-14
UNIV OF SCI & TECH BEIJING
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AI Technical Summary

Problems solved by technology

[0008] The method of the present invention is to comprehensively recycle valuable elements in iron-containing industrial waste residues, economically obtain reducing agent resources, and solve the comprehensive recycling of industrial waste residues and the problems encountered in the process of utilization, such as the prepared cold-solidified carbon-containing spheres The falling strength of the raw pellets is low, and the pellets are easy to burst after being put into the furnace, resulting in difficulty in reduction, etc., so the present invention is specially proposed to adapt to the production method of industrial operation

Method used

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Experimental program
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Effect test

Embodiment 1

[0018] The technological process of the present invention is: batching-mixing-pellet-drying-preheating-reduction-metallized pellets;

[0019] Ingredients: use iron-containing industrial waste residue with an iron grade of 51%; the selected reducing agent powder components are: fixed carbon 79.98%, ash content 13.94%, volatile matter 6.08%; the selected binder is corn flour, and the added concentration is 4 % sodium hydroxide solution. Mix according to the ratio of iron-containing industrial waste: reducing agent powder: binder=100:15:2.5, the amount of water added is 18%, and the bottom material in the rotary hearth furnace is cinder.

[0020] Mixing and making pellets: Add the above-mentioned raw materials in proportion to the mixer, and after mixing, press them into pellets with a double-roller ball press. The size of the pellets is 40×30×21mm

[0021] Drying: Dry the pressed pellets at 200°C for 3 hours

[0022] Preheating: put the dried carbon-containing pellets into the...

Embodiment 2

[0027] The technological process of the present invention is: batching-mixing-pellet-drying-preheating-reduction-metallized pellets;

[0028]Ingredients: Iron-containing industrial waste slag with an iron grade of 45% is selected, and 30% of ordinary iron concentrate powder with an iron grade of 63% is selected; the components of the selected reducing agent powder are: fixed carbon 86.47%, ash 4.95%, volatile matter 8.58%; the selected binder is bentonite. Mix according to the ratio of iron-containing industrial waste: reducing agent powder: binder=100:20:2.5, the amount of water added is 20%, and the bottom material in the rotary hearth furnace is the reducing agent powder mixed in the pellets.

[0029] Mixing and making pellets: Add the above-mentioned raw materials in proportion to the mixer, and after mixing, press them into pellets with a double-roller ball press. The size of the pellets is 40×30×21mm

[0030] Drying: Dry the pressed pellets at 300°C for 1.5h

[0031] P...

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PUM

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Abstract

The invention relates to a direct reduction method for treating industrial waste slag in a rotary hearth furnace, belonging to a new direct reduction ironmaking process in the metallurgical industry. The main process is: ingredients - mixing - pellets - drying - preheating - reduction - metallized pellets. Metallized pellets with a metallization rate of over 80% can be obtained after reduction in a rotary hearth furnace. The present invention comprehensively recycles and utilizes valuable elements in iron-containing industrial waste residues, economically obtains reducing agent resources, and solves the problem of low falling strength of cold solidified carbon-containing pellets prepared in the process of comprehensive recycling of industrial waste residues It has the advantages of high metallization rate, simple operation, easy control of process conditions, less equipment investment, low production cost, easy to meet raw material conditions, etc., and the overall process is more energy-saving than the furnace smelting process. It is also more environmentally friendly, and more importantly, the method can comprehensively recycle industrial waste, reduce its pollution to the environment, and save energy and protect the environment.

Description

technical field [0001] The invention relates to a direct reduction treatment method of industrial waste residue. Specifically, carbon-containing pellets are made from discarded iron-containing industrial waste slag and carbonaceous reducing agent, and then reduced in a rotary hearth furnace to obtain metallized pellets. Background technique [0002] With the rapid development of my country's steel production, the amount of imported iron ore is also increasing year by year. Although the import price of iron ore has soared all the way, 619 million tons of iron ore were still imported in 2010, and the dependence on imported iron ore was as high as 63%. Therefore, it is urgent to broaden the sources of ironmaking raw materials in my country. [0003] The rapid development of the chemical industry, while promoting the advancement of the national and local social economy, also brings a series of related negative problems. Many domestic enterprises have problems such as extensiv...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21B13/00
CPCY02P10/20
Inventor 张建良王春龙刘征建苏步新邢相栋王广伟孔德文杨广庆
Owner UNIV OF SCI & TECH BEIJING
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