The grinding fineness of phosphate ore determines whether the phosphate ore can be dissociated into monomers and separated from gangue minerals, and further affects the flotation efficiency of phosphate ore, and then affects the final concentrate grade and recovery rate. Therefore, the determination of phosphate ore grinding fineness is an important topic worthy of study.
The grinding fineness of phosphate ore is determined through a series of experimental studies and process mineralogy analysis, mainly considering factors such as mineral dissociation degree, flotation effect and economic benefits. The following are some key steps and methods for determining the optimal value of phosphate ore grinding fineness:
Use equipment such as mineral dissociation degree tester (MLA) to study the chemical composition, element distribution, mineral composition, dissociation degree and symbiotic relationship of phosphate ore. The appropriate grinding fineness can be determined by determining the dissociation degree of minerals under different grinding fineness conditions.
Obtain better test parameters through single factor condition test, such as reverse flotation demagnesium reagent conditions, reverse flotation desiliconization reagent conditions, etc., to determine the optimal grinding fineness.
Through experimental research on the effect of grinding fineness on flotation effect, the optimal grinding fineness is determined. For example, with the increase of grinding fineness, the concentrate grade first remains stable and then gradually increases, while the recovery rate is higher when the grinding fineness reaches a certain proportion.
Under the premise of meeting the beneficiation effect, the impact of grinding fineness on energy consumption and cost is considered. Appropriate grinding process parameters can increase the effective phosphorus content and citric acid solubility of phosphate rock powder, while reducing energy consumption.
Determine the appropriate grinding fineness of the ore through experimental research. For example, a low-grade phosphate mine in Mabian, Sichuan, was determined to have a suitable grinding fineness of -0.074mm65% through a series of conditional experiments.
While determining the grinding fineness, the flotation closed-circuit process flow and parameters also need to be considered to ensure the best flotation effect under the condition that the original ore contains P2O5.
The experimental results show that the shorter the grinding time, the smaller the grinding fineness. As the grinding time increases, the grinding fineness increases. According to the flotation experiment, the grinding time is 7 minutes and the grinding fineness is 8.5%.
In short, the determination of the grinding fineness of phosphate ore needs to consider many factors comprehensively, and through the grinding test of the ore sample, the fineness that can be dissociated and separated from the gangue minerals is selected, which is the appropriate fineness. It should also be noted that the fineness of phosphate ore grinding is not the finer the better. In the grinding process, over-grinding should be avoided to produce serious mud problems, which will inevitably increase the hidden dangers for subsequent flotation, so it is very important to master the scale.
