Study On The Occurrence And Removal Mechanism Of Phosphorus In Huangling Coal

Huangling mining area is one of the five main mining areas in Huanglong coalfield.Clean and efficient utilization of resources in the area is the key to maximize resource benefits and low-carbon economy.The phosphorus element in the coal of Huangling mining area is abnormal,which restricts the application of coal resources in the area.It is necessary to accurately understand the occurrence law of this element in coal and carry out directional removal of it.This paper takes the phosphorus element in No.1 Coal Mine of Huangling mining area as the research object,systematically studies the occurrence state of phosphorus element in Huangling coal,deeply discusses the removal method of phosphorus through flotation,and seeks the best flotation conditions and removal rate.A kind of Through the analysis of coal quality characteristics of Huangling coal sample,Huangling coal sample belongs to low medium ash coal,medium volatile coal,medium fixed carbon coal and low sulfur coal.Phosphorus in three coal samples was analyzed by phosphorus molybdenum blue spectrophotometry(GB/T 5059-2007).The phosphorus content of three coal samples in Huangling coal was higher than 0.1%,which belonged to high phosphorus coal.The occurrence state of phosphorus in Huangling coal was studied by XRD,SEM-EDS analysis,sieving float and sink test,correlation analysis,step by step chemical extraction and the relationship between phosphorus and fluorine in coal.The screening test shows that the ash content of coal sample generally decreases with the decrease of coal particle size;the sulfur content generally changes irregularly with the coal sample particle size;and thephosphorus content decreases gradually with the decrease of coal sample particle size.It isspeculated that the correlation between phosphorus content and ash content is very high,but the correlation between phosphorus content and sulfur content is not high.The results of float and sink tests show that with the increase of density class of coal sample,the ash content of each density grade product in coal sample also increases gradually.The ash content of coal sample with density class greater than 1.8 g/cm3 is higher than that with density class less than 1.3 g/cm3,indicating that most minerals in coal sample exist in density class greater than 1.8 g/cm3,The results show that the sulfur content in coal samples increases with the increase of density class.The sulfur content of low density coal samples is obviously lower than that of high density coal samples,which indicates that the inorganic sulfur content is higher than the organic sulfur content;the phosphorus content in coal samples also increases with the increase of density class,and the phosphorus content of three coal samples is the highest in the products of density class greater than 1.8 g/cm3.The correlation analysis shows that there is a strong correlation between phosphorus content and ash content,indicating that the inorganic affinity of phosphorus is strong.Phosphorus exists as inorganic matter in coal,and phosphorus content is not related to sulfur content,indicating that there is no sulfur-containing minerals in the occurrence form of phosphorus.The stepwise chemical extraction showed that the main proportion of phosphorus in the three coal samples was inorganic,which was more than 85%.Through XRD and SEM-EDS,it is confirmed that the phosphorus in coal samples exists in the form of fluorapatite.Finally,the relationship between phosphorus and fluorine in coal is studied,and it is further confirmed that phosphorus in coal samples exists in the form of fluorapatite.In this paper,the flotation test of Huangling coal sample was carried out.The effect of various factors,such as flotation time,flotation concentration,collector and frother dosage,on phosphorus removal in coal was studied.The optimum flotation conditions were obtained through analysis:flotation time was 3 min,flotation concentration was 80 g/L,and the dosage of new collector KH(modified fatty acid)was 140 The results show that the average removal rate of phosphorus in coal sample is 68.8%when the amount of secondary octanol is 100 g/t.