Study on leaching extraction of high purity potassium chloride from sintering machine head ash
In order to achieve high value-added utilization of potassium chloride in the ash of sintering machine head,elec-trostatic precipitator dust from the sintering machine head and high-salt alkaline wash dewatering were used as raw materi-als.By adopting the process route of pretreatment,high salt wastewater synergistic water elution of potassium,vacuum filtra-tion,impurity removal and decolorization,solid-liquid separation,and salt crystallization,Box Behnken experiment was de-signed.The mathematical model between three factors of leaching temperature,liquid-solid ratio,and stirring speed,and the removal rate of potassium from sintering machine head ash was established.The removal rate of ash and potassium from sin-tering machine head was optimized by using Box Behnken method,and salt crystallization was carried out by measuring the solubility of sodium chloride and potassium chloride at different temperatures.The response surface analysis experimental results showed that the degree of influence of three factors on the removal rate of potassium in the ash of the sintering ma-chine head was in descending order:leaching temperature,liquid-solid ratio,and stirring speed.The optimal process condi-tions for leaching were a leaching temperature of 51.45 ℃,a liquid-solid mass ratio of 2.85∶1,a stirring rate of 674 r/min,and a potassium removal rate of 93.89％after 30 minutes.After impurity removal and decolorization treatment of potassium containing filtrate,the NaCl-KCl-H2O water salt system phase diagram was used to control the evaporation conditions for salt crystallization,so that the flash endpoint was controlled within the single solid phase crystallization zone of potassium chloride,and a purity of 92％potassium chloride product could be obtained.
sintering machine head ashsynergisticresponse surface methodsalt separationpotassium chloride
万方数据
维普
