Preenrichment-three segment suspension roasting-magnetic separation treatment method of complex refractory iron ores

A technology of suspension roasting and treatment methods, applied in chemical instruments and methods, magnetic separation, solid separation, etc., can solve problems such as waste of resources, poor sorting indicators, and unsynchronized reactions, and achieve efficient recycling, improved recovery, and The effect of improving the recovery rate

Active Publication Date: 2015-08-05
上海逢石科技有限公司
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  • Abstract
  • Description
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AI Technical Summary

Problems solved by technology

[0003] Hematite-siderite-limonite-magnetite mixed ore is a typical complex refractory iron ore resource, widely distributed in Liaoning, Shanxi, Shaanxi, Gansu, Xinjiang and other places; the mineral composition of this type of iron ore is extremely Complex, the main minerals are hematite, magnetite, siderite, quartz, iron dolomite, etc., of which iron in hematite accounts for 30-80%, iron in siderite accounts for 5-20%, limonite The iron in the ore accounts for 5-20%, and the iron in the magnetite accounts for 5-20%. Due to the complex mineral composition and close symbiotic relationship of the ore, there are many types of iron-containing minerals, and the separation properties vary greatly. Technology is difficult to obtain better technical and economic indicators; Northeastern University and Dong'anshan Sintering Plant adopt "step-by-step flotation" technology to process Dong'anshan carbonate-bearing iron ore (belonging to hematite-siderite-limonite-magnetic Iron ore mixed ore), obtained the industrial technical index of TFe grade 63.37%, recovery rate only 60~65%
[0004] Magnetization roasting-magnetic separation refers to heating materials or ores in the corresponding atmosphere to perform complex physical and chemical actions, so that weak magnetic iron minerals can be transformed into strong magnetic iron minerals (Fe 3 o 4 ), and then use the magnetic difference between minerals for magnetic separation; common methods of magnetization roasting include shaft furnace roasting, rotary kiln roasting, fluidized roasting, etc. 3 Shaft furnace roasting technology processes this type of ore. The roasted ore can be subjected to weak magnetic separation to obtain iron concentrate with a TFe grade of 55%-56%, and the iron recovery rate is 70-80%. However, the ore size suitable for shaft furnace processing is 25-75mm. About 40% of the 0-25mm ore in Jiuquan Iron and Steel Concentrator can only use the strong magnetic separation process, which can only obtain iron concentrate with a TFe grade of 49.06%, and the iron recovery rate is 66.59%, resulting in a large waste of resources; and the shaft furnace roasting process There are problems such as high energy consumption, long roasting time, uneven product quality, etc.
[0005] When the above magnetization roasting technology is used to process hematite-siderite-limonite-magnetite mixed ore, there are three problems as follows: 1. Due to the inconsistency of iron mineral properties, the reactions of different minerals under the same reduction conditions are not synchronized , the reducing material cannot completely react to generate magnetic Fe 3 o 4 , or there is over-reduction to generate non-magnetic FeO, which leads to poor sorting indicators; 2. The heating and reduction of materials are carried out simultaneously, and the reduction atmosphere is difficult to guarantee, and it is difficult to implement industrialization; 3. It cannot handle 0~25mm fine-grained materials

Method used

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  • Preenrichment-three segment suspension roasting-magnetic separation treatment method of complex refractory iron ores
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  • Preenrichment-three segment suspension roasting-magnetic separation treatment method of complex refractory iron ores

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Experimental program
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Effect test

Embodiment 1

[0054] The main components of the complex refractory iron ore used are shown in Table 1 (unit wt%);

[0055] Table 1

[0056] components TF FeO SiO 2 Al 2 o 3 CaO content 34.43 12.8 49.41 0.15 0.39 components MgO P S K Na content 0.37 0.07 0.05 0.04 0.03

[0057] The chemical phase analysis results are shown in Table 2;

[0058] Table 2

[0059]

[0060] The method proceeds as follows:

[0061] 1. Pre-magnetic separation: Grind the complex and refractory iron ore to a particle size of -0.074mm, accounting for 40% of the total weight, and then perform weak magnetic separation to obtain weak magnetic concentrate and weak magnetic tailings; The ore is subjected to strong magnetic separation to obtain strong magnetic separation concentrate and strong magnetic separation tailings; strong magnetic separation concentrate is a mixture of hematite, siderite and limonite;

[0062] 2. Pre-oxidation: Put the high-strength ...

Embodiment 2

[0069] The iron grade of the complex refractory iron ore is 32% TFe, containing 16% FeO, SiO 2 45%;

[0070] Method is with embodiment 1, and difference is:

[0071] (1) The part that grinds the complex refractory iron ore to a particle size of -0.074mm accounts for 50% of the total weight;

[0072] (2) Heat the material in the suspension roaster to 700°C for pre-oxidation roasting, and the pre-oxidation time is 30s;

[0073] (3) The reduction time is 15 seconds; the volume flow ratio of CO and nitrogen is 1:3;

[0074] (4) When the temperature drops to 350°C, air is introduced into the suspension roaster for reoxidation; the main component of the reoxidized material is magnetic iron γ-Fe 2 o 3 and Fe 3 o 4 ; where γ-Fe 2 o 3 The weight content is 60%, Fe 3 o 4 The weight content is 33%;

[0075] (5) When the part of the material after the second grinding to the particle size -0.044mm accounts for 50% of the total weight, the material after the second grinding is ...

Embodiment 3

[0077] The iron grade of complex refractory iron ore is 30% TFe, containing 15% FeO, SiO 2 38%;

[0078] Method is with embodiment 1, and difference is:

[0079](1) The part that grinds the complex refractory iron ore to a particle size of -0.074mm accounts for 60% of the total weight;

[0080] (2) Heat the material in the suspension roaster to 600°C for pre-oxidation roasting, and the pre-oxidation time is 60s;

[0081] (3) The reduction time is 30 seconds; the volume flow ratio of CO and nitrogen is 1:5;

[0082] (4) When the temperature drops to 300°C, air is introduced into the suspension roaster for reoxidation; the main component of the reoxidized material is magnetic iron γ-Fe 2 o 3 and Fe 3 o 4 ; where γ-Fe 2 o 3 The weight content is 80%, Fe 3 o 4 The weight content is 14%;

[0083] (5) When the part of the material after the second grinding to the particle size -0.044mm accounts for 60% of the total weight, the material after the second grinding is subje...

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Abstract

The invention discloses a preenrichment-three segment suspension roasting-magnetic separation treatment method of complex refractory iron ores, and belongs to the technical field of mineral processing. The method comprises the following steps: 1, levigating the complex refractory iron ores, carrying out weak magnetic separation, and carrying out strong magnetic separation on mine tailings; 2, putting concentrate obtained after strong magnetic separation in a suspension roasting furnace, and heating to 450-800DEG C in a suspension state in order to carry out pre-oxidation roasting; 3, introducing nitrogen to displace air, and introducing a reducing gas to carry out reduction in a suspension loose state; 4, introducing air when the temperature decreases to 250-400DEG C in order to oxidize, taking out the obtained material when the temperature decreases to below 100DEG C, and carrying out ore milling; and 5, carrying out third segment magnetic separation, and mixing concentrate obtained after three segment magnetic separation with concrete obtained after the weak magnetic separation to obtain finial concentrate. The method has the advantages of simple process, improvement of the recovery rate of the complex refractory iron ores, strong adaptability, safe and reliable process, uniform and stable product quality, energy saving and consumption reduction.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and in particular relates to a pre-enrichment-three-stage suspension roasting-magnetic separation treatment method of complex refractory iron ore. Background technique [0002] With the rapid development of my country's iron and steel industry, the demand for iron ore has risen sharply. my country's iron ore has low grade, poor endowment, and high mining and dressing costs, resulting in domestic iron ore production that is far from meeting the needs of the development of the iron and steel industry; in 2014, my country imported 933 million tons of iron ore, and its dependence on foreign countries was as high as 78.5%. Excessive dependence on foreign iron ore has further reduced the international discourse power and security of China's steel industry; in 2014, the price of imported iron ore has dropped from US$130 / t at the beginning of the year to below US$70 / t, and domestic iron ore has...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B1/00C22B1/02B03C1/00
Inventor 韩跃新李艳军高鹏
Owner 上海逢石科技有限公司
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