Method for preparing high-quality phosphate concentrate

Abstract

The invention relates to a method for preparing high-quality phosphate concentrate. Reverse flotation is carried out in a micro-fine particle grade to remove SiO2 and sesquioxide mainly by means of the action of a reverse flotation reagent, and the technology is different from a widely used technology for removing SiO2 in a graded coarse particle grade through reverse flotation and directly discarding tailings in a fine particle grade. According to the method, the influence of slime in the fine fraction on flotation is avoided, and efficient reverse flotation removal of SiO2 and sesquioxide inmicro-fine particles is achieved. The phosphate concentrate prepared by the method can reduce the discharge amount of phosphogypsum in the wet-process phosphoric acid production process and improve the purity of calcium sulfate dihydrate in phosphogypsum.

Description

technical field [0001] The present invention specifically relates to a high P 2 o 5 , low SiO 2 The invention relates to a preparation method of phosphate concentrate with low sesquioxide content, which belongs to the fields of phosphate rock beneficiation and phosphogypsum emission reduction. Background technique [0002] my country has abundant reserves of phosphate rock resources, but most of them need beneficiation and processing before they can become qualified raw materials for downstream use. [0003] Because the production cost of positive flotation is high, most of the phosphate rock is processed by reverse flotation to remove carbonate gangue, so as to supply downstream wet phosphoric acid production. [0004] With the continuous development and utilization of phosphate rock resources, the phosphate rock resources are further depleted, and the phosphorous concentrate obtained by simply using reverse flotation to remove MgO from phosphate rock is increasingly una...

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Problems solved by technology

[0004] With the continuous development and utilization of phosphate rock resources, the phosphate rock resources are further depleted, and the phosphorous concentrate obtained by simply using reverse flotation to remove MgO from phosphate rock is increasingly unable to meet the needs of downstream wet-process phosphoric acid ore. requirements, on the one hand after MgO removal P 2 o 5 The recovery rate is reduced. On the other hand, the process cannot effectively reduce the sesquioxide content, which affects the production of wet-process phosphoric acid. At the same time, a large amount of silicate enters the wet-process phosphoric acid process, which also leads to low phosphoric acid production efficiency and phosphogypsum emissions. increase, the content of calcium sulfate dihydrate in phosphogypsum decreases

[0005] SiO from phosphate rock 2 From the point of view of the intercalation particle size characteristics of sesquioxide, SiO 2 Sesquioxide and sesquioxide are embedded in phosphate rock with fine particle size, especially the content of sesquioxide in the fine-grained grade is often many orders of magnitude higher than that in the coarse-grained grade. The treatment methods currently available for this characteristic It is to classify and desludge the fine particle level and directly throw the tail. This method will greatly reduce the recovery rate of phosphate ore, and the technical and economic indicators are extremely poor, so it is usually not adopted.

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