Study On Pellets Process For Preparation Of Yellow Phosphorus From Phosphate Rock

The method of making phosphoric acid mainly includes fire and wet methods.The fire method,also known as the thermal method,The first step is to produce yellow phosphorus and then produce phosphoric acid or other phosphoric acid products.With the increasing consumption of high quality phosphate rock,fewer and fewer phosphate rock can be used to produce yellow phosphorus.It is urgent to solve the problem of source of yellow phosphorus ore.On the other hand,a large amount of powdery ore can be produced during the crushing process of phosphate rock,which can not be directly used for the production of yellow phosphorus.If the powdered ore can be used in yellow phosphorus production after pelletizing,the above two problems can be solved and the efficient utilization of phosphate rock can be realized.Based on this,the pelletizing process for preparing yellow phosphorus from phosphate rock powder and phosphate concentrate was studied.Pelletizing and pressing balls of phosphorus concentrate and pressing balls of Phosphate rock were studied.The effects of binder dosage,water content,roasting temperature and roasting time on the pelletizing process were investigated.The main findings are as followed:?1?The compressive strength of phosphate concentrate pellets is 1053N/pellet,when the dosage of DS is 0.5%,the water content is 8%,the drying temperature is100?and the drying time is 80 min.The calcination temperature is 1000?,the calcination time is 35 min,and the compressive strength of the finished pellets is1423N/pellet.The pellets can meet the production requirements.?2?Under the conditions of 2.5%bentonite,6%water,100?preheating temperature,20 min preheating time,1100?roasting temperature and 20 min roasting time,the compressive strength of the finished pellet is 1045N/pellet,,and the pellet properties can meet the production requirements.?3?The compressive strength of phosphate rock pellet is 1120N/pellet,when the dosage of DS is 0.3%,the dosage of water is 8%,the drying temperature is 100?and the drying time is 80 min.The effect of particle size of phosphate rock powder on pellet strength was considered in the experiment.The pellet pressing test was carried out with different particle size of phosphate rock powder.The results showed that the particle size of phosphate rock powder had little effect on pellet strength.In the pellet roasting test,When calcination temperature is 1000?and the calcination time is 35min.the pellet's compressive strength was 1387N/piece,and the pellet's performance could meet the production requirements.?4?After pellet roasting,carbonate decomposition,P₂O₅ grade increased,three types of pellet grade increased by different magnitudes,the order of size is the highest in phosphate concentrate pelletizing,followed by phosphate rock powder pelletizing,phosphate concentrate pelletizing at least.?5?Phosphate concentrate and phosphate rock powder pelleting process,the final product ball can meet the current yellow phosphorus production requirements with phosphate rock.The adhesive DS has a good bonding effect in the direction of pressing the ball.It has the characteristics of low dosage,high compressive strength and short time of forming the ball.It has a good application prospect.