Process and system for removing phosphorus from vanadium solution in vanadium pentoxide produced from vanadium slag

Abstract

The invention provides a vanadium solution dephosphorization process and system used during production of vanadium pentoxide by vanadium slag. The dephosphorization system comprises a phosphate removing agent storage tank, a phosphate removing agent high-level gauging tank, a distribution vehicle, a first-grade thickener, a second-grade thickener, a transfer pump and a vacuum filtration pump. The process comprises the steps that clinker obtained by roasting the vanadium slag is loaded in the distribution vehicle and is leached, a leaching solution is delivered into the first-grade thickener through the vacuum filtration pump, the clinker in the distribution vehicle is washed with a phosphate removing agent in the phosphate removing agent storage tank in a sprayed manner to be subjected to primary dephosphorization and then continues being washed with water in the sprayed manner, and the leaching solution in the first-grade thickener continuously overflows into the second-grade thickener; a steam stirring solution is introduced into the second-grade thickener, the phosphate removing agent is delivered into the phosphate removing agent high-level gauging tank through the transfer pump, and the phosphate removing agent is delivered into the second-grade thickener to conduct secondary dephosphorization; and a qualified vanadium solution is obtained after the second-grade thickener stands still and the solution is clarified. The process and system have the advantages that the equipment utilization rate is high, the structure is reasonable, operation is convenient, consumption of the phosphate removing agent is little, less waste residues are produced in the dephosphorization process, and the vanadium recovery rate is high.

Description

technical field [0001] The invention belongs to the field of vanadium slag roasting and extracting vanadium, in particular to a vanadium solution dephosphorization process and system for producing vanadium pentoxide from vanadium slag. Background technique [0002] Vanadium-titanium magnetite is the main mineral resource of vanadium. Vanadium-titanium magnetite is smelted into vanadium-containing molten iron by blast furnace, then oxidized and blown by converter. After enrichment, vanadium enters the slag phase to obtain vanadium slag. The phosphorus content of the vanadium slag after smelting vanadium-titanium magnetite is 0.020-0.30%. When the vanadium slag is oxidized and sodiumized to extract vanadium and roast clinker, a large amount of phosphorus is converted into water-soluble phosphate, and the clinker is directly leached with water. The solution contains a large amount of phosphorus ions. In order to ensure that the phosphorus content in the vanadium pentoxide prod...

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Problems solved by technology

However, this method of phosphorus removal has the following disadvantages: (1) the amount of phosphorus removal agent is large, and the efficiency of phosphorus removal is low; (2) the loss of vanadium is large and the recovery rate is low. Vanadium in the solvent reacts with the solution and converts into insoluble calcium vanadate and enters the waste residue (containing 8-14% of vanadium), resulting in a large loss of vanadium; Phosphorus removal equipment such as stirring tanks did not make full use of the existing concentrators, distribution vehicles and other equipment in the vanadium extraction process; (4) The amount of waste residue generated during the phosphorus removal process was relatively large, and the amount of slag generated per ton of vanadium pentoxide was 200-350kg. polluted environment

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