Phosphate ore beneficiation: dual considerations of environmental protection and economic benefits

 China's phosphate rock resources are mainly sedimentary rock phosphate rock. This type of phosphate rock is difficult to beneficiated and requires complex beneficiation processes to meet industrial standards. According to the properties of different phosphate ores, the beneficiation processes used are also different. At present, commonly used phosphate ore beneficiation processes at home and abroad include forward flotation, reverse flotation, scrubbing and desliming processes, gravity separation, roasting and digestion, etc.

Positive flotation of phosphate rock

The positive flotation process first uses inhibitors to suppress non-phosphorus minerals, and then uses collectors to attach phosphorus minerals to bubbles for flotation. This process is simple and suitable for processing low- to medium-grade phosphate rock. It is especially effective for sedimentary phosphate rock and can effectively remove impurities. However, a disadvantage of this process is that it often needs to be carried out at a specific temperature, resulting in high energy consumption.

Anti-flotation

The reverse flotation process mainly targets phosphate rocks with high carbonate content and low silicon content. The process is simple to operate, does not require heating, and can be carried out at low or normal temperatures. Therefore, energy consumption and cost are low, and it is easy for industrial application. However, its limitation lies in its weak applicability.

Scrubbing and desliming process

The scrubbing and desliming process is a physical beneficiation method, especially suitable for phosphate rocks with high weathering degree and large mud content. Although its scope of application is limited, it can effectively reduce energy consumption and chemical usage, while improving the grade of phosphate rock and significantly improving the removal rate of harmful impurities such as iron, aluminum, and magnesium.

Grain selection process

The gravity separation process is also a physical mineral separation method based on mineral density differences. This process is simple to operate, has good mineral processing effect, and is environmentally friendly, but it is usually suitable for sorting ores with large density differences. The effect of using the gravity separation process alone is often unsatisfactory, so a more widely used process is the combined process of gravity separation and flotation, which can achieve better mineral processing results.

roasting digestion process

The roasting and digestion process is a direct and clean mineral processing method, mainly used to improve the grade of carbonate phosphate rock. During the roasting process, carbonate decomposes to produce CO2, CaO and MgO. Subsequently, through water digestion treatment, CaO and MgO are converted into Ca(OH)2 and Mg(OH)2 particles. After desliming treatment, calcium, Impurities such as magnesium, and finally obtain phosphate concentrate