Method for preparing ground phosphate pellets for yellow phosphorus production by utilizing medium-low-grade ground phosphate rock

Abstract

The invention discloses a method for preparing ground phosphate pellets for yellow phosphorus production by using medium-low-grade ground phosphate rock, which comprises the following steps: mixing modified industrial paper pulp waste liquid, modified yellow phosphorus slag, a powdered carbon raw material, a ground phosphate rock raw material and mud phosphorus slag as main raw materials, and pressing the mixture into balls. By means of the method, recycling of solid waste such as medium-low-grade phosphate rock, yellow phosphorus slag and mud phosphorus slag can be effectively achieved, the obtained yellow phosphorus pellets have the advantages of being large in grade improvement, high in compressive strength and the like, and an effective way can be provided for recycling of medium-low-grade ground phosphate rock and the like; and the related preparation method is simple and relatively low in energy consumption, and has important economic and environmental benefits.

Description

technical field [0001] The invention belongs to the technical field of phosphorus chemical industry, and in particular relates to a method for preparing phosphate rock pellets for yellow phosphorus production by utilizing medium and low-grade phosphate rock powder. Background technique [0002] my country's phosphate rock resources are abundant, but the rich ore (P 2 o 5 Grade greater than 30%) accounted for only 7%, medium and low grade phosphate rock (P 2 o 5 The grade is 20-26%) accounts for about 90% of the total reserves of phosphate rock in my country, and the utilization of medium and low grade phosphate rock is less in industry at present. One of the main uses of phosphate rock is to prepare phosphoric acid, and yellow phosphorus is an important raw material for preparing phosphoric acid. According to the characteristics of phosphate rock in my country, the lump ore that can be used to produce yellow phosphorus only accounts for 2% of the total amount of phosphat...

AI Technical Summary

Problems solved by technology

On the one hand, the ore used for yellow phosphorus production is getting less and less; on the other hand, in the lump ore crushing and processing project, a large amount of powder ore is produced which cannot be reused, further causing waste of resources

In addition, during the production of yellow phosphorus, two solid wastes, yellow phosphorus slag and sludge phosphorus slag, are produced, which also waste some useful phosphate rock resources.

[0003] Sludge phosphorus slag is one of the main by-products in the yellow phosphorus production process. It has fine particle size and complex composition. It is a dangerous solid waste, but its phosphorus content reaches 10-20%. Currently, the main method of treating sludge phosphorus is to recover elements Phosphorus and the preparation of phosphorus compounds, but this method cannot deal with depleted sludge phosphorus and the treatment cost is high, and the flue gas and dust pollution in the treatment process is high. If this part of phosphorus can be utilized in the yellow phosphorus production process, it will not only have high economic benefits , it can also alleviate the pollution of the sludge and phosphorus slag to the environment

Yellow phosphorus slag is another by-product in the production process of yellow phosphorus. At present, it is mainly used in building materials, but the economic benefits are low, so there are also problems such as low utilization rate and large storage capacity, and a lot of financial resources are spent every year. and energy to deal with the pollution caused by yellow phosphorus slag

[0004] Phosphate rock pellets are one of the raw materials for the production of yellow phosphorus. One of the necessary raw materials used in the pellet preparation process at this stage is a binder. At present, inorganic binders are widely used, including water glass, slaked lime, bentonite, etc. , but there are certain problems: as the modulus of water glass is different, the structural strength of pellet products is also different, and most of them do not meet the production requirements, and the preparation process of high-quality water glass that meets the production requirements is complicated and expensive; the main component of hydrated lime It is calcium hydroxide (strongly alkaline). Calcium ions will be introduced when slaked lime is used, which will not only affect the phosphorus content of the raw ore, but also increase the amount of flux used; although the most widely used bentonite is cheap, it is used in a large amount. And part of the bentonite will adsorb phosphorus, and the prepared pellets will cause phosphorus to be lost into the slag during the production of yellow phosphorus, resulting in a certain degree of waste

The production process of yellow phosphorus also needs another main raw material, carbon. In industry, lump white coal and coke are generally the main materials, but the cost is relatively high.

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