Method for preparing lithium iron phosphate and lithium iron pyrophosphate by taking mineral leaching tail liquor as iron source

A technology of lithium iron pyrophosphate and lithium iron phosphate, which is applied in the field of comprehensive utilization of industrial wastewater, can solve problems such as hidden environmental hazards, no utilization value, and difficult treatment, and achieve the effects of low price, resource utilization, and easy precipitation and recovery.

Inactive Publication Date: 2015-04-29
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the colloidal nature of the former, it is difficult to precipitate, which causes great difficulties for subsequent treatment, and the mixture of ferric hydroxide

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] 1) One thousand liters of leaching tailings from a mine, containing 9.8 g / L of iron, pour a 5% trisodium phosphate solution into the leaching tailings pool, stir and check the pH until the pH reaches 3.0 and precipitates form ;

[0044] 2) Spray 5 kg of non-ionic polyacrylamide (PAM) solution with a concentration of 0.1% evenly into the tail liquid pool and stir;

[0045] 3) Stand still for 8 hours to precipitate the suspension, dehydrate the sediment by pressure filtration, rinse with cold water, and dry the solid phase at 90°C to obtain ferric phosphate;

[0046] 4) Mix iron phosphate + lithium formate evenly at a molar ratio of 1:1, grind together for 0.5 hours, put them in a closed container, heat to 500°C in a nitrogen atmosphere, and cool to room temperature to obtain lithium iron phosphate.

Embodiment 2

[0048] 1) One thousand liters of ore leaching tailings from a mine, containing 15.6 g / L of iron, pour 10% disodium hydrogen phosphate solution into the leaching tailings pool, stir and check the pH until the pH reaches 3.5 and there is precipitation form;

[0049] 2) Spray 50 kg of non-ionic polyacrylamide (PAM) solution with a concentration of 0.01% evenly into the tail liquid pool and stir;

[0050] 3) Stand still for 4 hours to precipitate the suspension, dehydrate the sediment by pressure filtration, rinse with cold water, and dry the solid phase at 80°C to obtain ferric phosphate;

[0051] 4) Mix iron phosphate + lithium formate evenly at a molar ratio of 1:1, grind them together for 1 hour, put them in a closed container, heat to 600°C in an argon atmosphere, and cool to room temperature to obtain lithium iron phosphate.

Embodiment 3

[0053] 1) One thousand liters of ore leaching tailings from a mine, containing 21 g / L of iron, pour 8% sodium dihydrogen phosphate solution into the leaching tailings pool, stir and check the pH until the pH reaches 4.0 and there is precipitation form;

[0054] 2) Spray 20 kg of non-ionic polyacrylamide (PAM) solution with a concentration of 0.05% evenly into the tail liquid pool and stir;

[0055] 3) Stand still for 6 hours to precipitate the suspension, dehydrate the sediment by pressure filtration, rinse with cold water, and dry the solid phase at 90°C to obtain ferric phosphate;

[0056] 4) Mix iron phosphate + lithium oxalate evenly at a molar ratio of 2:1, grind together for 1 hour, put them in a closed container, heat to 550°C in an argon atmosphere, and cool to room temperature to obtain lithium iron phosphate.

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PUM

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Abstract

The invention discloses a method for preparing lithium iron phosphate and lithium iron pyrophosphate by taking mineral leaching tail liquor as an iron source. The method comprises the following steps: spraying a phosphate or pyrophosphate solution into the mineral leaching tail liquor, adding an organic flocculant after complete precipitation, and dehydrating and drying the precipitate to obtain ferric phosphate or ferric pyrophosphate; uniformly mixing ferric phosphate with lithium formate, or lithium acetate, or lithium oxalate, grinding the mixture, heating the ground mixture in a protective atmosphere, and cooling to obtain lithium iron phosphate or lithium iron pyrophosphate; and uniformly mixing ferric pyrophosphate with sodium pyrophosphate and lithium formate, or lithium acetate, or lithium oxalate, grinding the mixture, drying the ground mixture in a drying oven, heating the dried mixture in a protective atmosphere, cooling to the room temperature, leaching, and drying to obtain lithium iron pyrophosphate. The method realizes recycling of dissolved iron while achieving harmless disposal of mineral leaching tail liquor, and the prepared lithium iron phosphate and lithium iron pyrophosphate are easy for precipitation and recovery, are materials for manufacturing zincodes, are not cheap and have a wide market prospect.

Description

technical field [0001] The invention relates to a comprehensive utilization technology of industrial wastewater, in particular to a method for preparing lithium iron phosphate and lithium iron pyrophosphate by using ore leaching tailing liquid as an iron source. Background technique [0002] Heap leaching of low-grade sulfide ores is often used to extract useful elements in the ore. When the useful elements are extracted, the resulting leaching tailings are bulky, strongly acidic, and contain a high concentration of ferric sulfate And sulfuric acid, improper disposal will cause great harm to the environment. [0003] At present, lime milk neutralization method is mostly used to treat this kind of wastewater. The neutralization process will produce a large amount of suspended solids, mainly iron hydroxide and calcium sulfate. Because the former has a colloidal nature, it is difficult to precipitate, which causes great difficulties for subsequent treatment, and the mixture of...

Claims

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Application Information

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IPC IPC(8): C01B25/45C01B25/42
Inventor 叶瑛秦雯丽夏天夏枚生张平萍陈雪刚张维睿
Owner ZHEJIANG UNIV
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