A method for preparing iron phosphate and iron pyrophosphate by using leaching tailings as iron source

Abstract

The invention discloses a method for preparing ferric phosphate and ferric pyrophosphate by using an ore leaching tail liquid as an iron source. The method comprises the following steps: 1) while stirring, spraying a 5-10 wt% phosphate or pyrophosphate solution into the ore leaching tail liquid until the pH value is equal to 3.5-4.5 and a precipitate is formed; 2) standing for 0.5-2 hours, and spraying a 0.1-0.3% organic flocculant solution into the suspension, wherein the flocculant solution accounts for 0.5-5 wt% of the ore leaching tail liquid; and 3) standing for 4-12 hours to precipitate the suspension, dewatering the precipitate by vacuum filtration or pressure filtration, eluting with cold water, and baking the solid phase at 80-90 DEG C to obtain the ferric phosphate or ferric pyrophosphate. On the premise of implementing harmless treatment on the ore leaching tail liquid, the method recovers the dissolved-state iron in the ore leaching tail liquid, and the obtained ferric phosphate or ferric pyrophosphate is a raw material for preparing lithium ion batteries.

Description

technical field [0001] The invention relates to a comprehensive utilization technology of industrial waste water, in particular to a method for preparing iron phosphate and 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 ferric hydroxi...

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 and calcium sulfate is basically useless and can only be stored in tailings ponds, which not only occupies land, but also still exists in the environment. Hidden danger

[0004] On the other hand, after the copper, lead, zinc and other industrial elements in the leaching tailings are extracted, the purity and concentration of iron ions are relatively high. The existing treatment methods for this type of wastewater do not consider the recycling of iron, resulting in waste of resources